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Reproductive phasiRNAs (phased, small interfering RNAs) are broadly present in angiosperms and play crucial roles in sustaining male fertility. While the premeiotic 21-nt (nucleotides) phasiRNAs and meiotic 24-nt phasiRNA pathways have been extensively studied in maize (Zea mays) and rice (Oryza sativa), a third putative category of reproductive phasiRNAs-named premeiotic 24-nt phasiRNAs-have recently been reported in barley (Hordeum vulgare) and wheat (Triticum aestivum). To determine whether premeiotic 24-nt phasiRNAs are also present in maize and related species and begin to characterize their biogenesis and function, we performed a comparative transcriptome and degradome analysis of premeiotic and meiotic anthers from five maize inbred lines and three teosinte species/subspecies. Our data indicate that a substantial subset of the 24-nt phasiRNA loci in maize and teosinte are already highly expressed at the premeiotic phase. The premeiotic 24-nt phasiRNAs are similar to meiotic 24-nt phasiRNAs in genomic origin and dependence on DCL5 (Dicer-like 5) for biogenesis, however, premeiotic 24-nt phasiRNAs are unique in that they are likely i) not triggered by microRNAs, ii) not loaded by AGO18 proteins, and iii) not capable of mediating PHAS precursor cleavage. In addition, we also observed a group of premeiotic 24-nt phasiRNAs in rice using previously published data. Together, our results indicate that the premeiotic 24-nt phasiRNAs constitute a unique class of reproductive phasiRNAs and are present more broadly in the grass family (Poaceae) than previously known.

BackgroundThis pilot assessed transfusion requirements during resuscitation with whole blood followed by standard component therapy (CT) versus CT alone, during a change in practice at a large urban Level I trauma center.MethodsThis was a single-center prospective cohort pilot study. Male trauma patients received up to 4 units of cold-stored low anti-A, anti-B group O whole blood (LTOWB) as initial resuscitation followed by CT as needed (LTOWB + CT). A control group consisting of women and men who presented when LTOWB was unavailable, received CT only (CT group). Exclusion criteria included antiplatelet or anticoagulant medication and death within 24 hours. The primary outcome was total transfusion volume at 24 hours. Secondary outcomes were mortality, morbidity, and intensive care unit- and hospital-free days.ResultsThirty-eight patients received LTOWB, with a median of 2.0 (interquartile range [IQR] 1.0-3.0) units of LTOWB transfused. Thirty-two patients received CT only. At 24 hours after presentation, the LTOWB +CT group had received a median of 2,138 mL (IQR, 1,275-3,325 mL) of all blood products. The median for the CT group was 4,225 mL (IQR, 1,900-5,425 mL; p = 0.06) in unadjusted analysis. When adjusted for Injury Severity Score, sex, and positive Focused Assessment with Sonography for Trauma, LTOWB +CT group patients received 3307 mL of blood products, and CT group patients received 3,260 mL in the first 24 hours (p = 0.95). The adjusted median ratio of plasma to red cells transfused was higher in the LTOWB + CT group (0.85 vs. 0.63 at 24 hours after admission; p = 0.043. Adjusted mortality was 4.4% in the LTOWB + CT group, and 11.7% in the CT group (p = 0.19), with similar complications, intensive care unit-, and hospital-free days in both groups.ConclusionBeginning resuscitation with LTOWB results in equivalent outcomes compared with resuscitation with CT only.Level of evidenceTherapeutic (Prospective study with 1 negative criterion, limited control of confounding factors), level III.

This study seeks to examine the effectiveness of peer-led team learning (PLTL) pedagogy when it is implemented in an entirely online environment. Past evaluations of PLTL have demonstrated the effectiveness of this approach when used with in-person teaching, but an online environment is expected to pose unique challenges to students, and therefore, the past work may not generalize to an online environment. The study implemented PLTL within four classes of second-semester general chemistry each offered online. The classes were evaluated in reference to six classes of the same course, also taught exclusively online, that relied primarily on didactic instruction. The evaluation showed the average score for students with online PLTL ranged from 0.15 to 0.20 standard deviations better than students with online didactic across the tests and final exams and that this difference was partially explained by past performance. Further, online PLTL students had a higher likelihood of earning a passing grade in the class which corresponded with a lower proportion of students failing and a lower proportion of students withdrawing from the course. The results indicate that PLTL was an effective instructional technique within an online modality at the research setting.

Prior research has demonstrated the important role of chemistry students' affect in academic performance. Likert-scale surveys are the most prevalent tools to measure students' affect within chemistry education research, however, data collected through a Likert-scale survey may exhibit response style bias which can hinder accurately measuring students' affect. This study investigates the utility of a novel survey methodology, termed rank-sort survey, in understanding students' academic motivation in a general chemistry course. Informed by Q methodology, in a rank-sort survey participants rank a set of statements in terms of level of agreement with limits in place on how many items can be assigned a particular rank. In this investigation, a rank-sort survey was developed by using statements from an existing Likert-scale instrument, the Academic Motivation Survey in Chemistry. Data collected from the rank-sort surveys, compared to Likert-scale surveys, showed a better alignment with self-determination theory, the underlying theoretical framework, and a better ability to predict students' academic performance in chemistry. The study also discusses which surveys in chemistry education research are likely to benefit from adopting a rank-sort approach.

Representations are ubiquitous in chemistry. They are part of the chemistry language instructors use to communicate chemistry phenomenon to students. Literature calls in support of learning with multiple representations, but there is a pre-requisite for students to learn from a single representation. In this exploratory study, 1086 students in second semester general chemistry were randomly assigned to one of four representations showing bonding of sulfur dioxide: chemical formula, Lewis dot structure, an image of a ball and stick model, or an image of a space filling model. Students were asked to predict chemical properties of sulfur dioxide: relative bond length, molecular polarity, and the strongest intermolecular force with a water molecule. Using the lens of Multimedia Learning Theory on Learning with Text and Visual Representations, analyses of students' prediction of chemical properties and the features cited when making predictions was conducted. Effect sizes were used to describe variations among representations in terms of how students predicted bond length, polarity and intermolecular forces. Meaningful differences were found across representations in students' ability to correctly predict relative bond length and molecular polarity. These explorations generated the following hypotheses: (1) chemical formula leads students to depend on chemical conventions, (2) Lewis dot structure hinders predicting polarity when it shows an inaccurate shape, and (3) visual representations of ball and stick and space filling cue students to rely on visual estimations more than the other representations. Upon further testing, these hypotheses can inform instructors how to introduce representations and in the decision-making process of which representations to use to convey or assess a specific chemical property.

Some students struggle with chemistry because they do not find the relevance between chemistry content and their lives or they perceive their intelligence as fixed. Social-psychological interventions (SPIs), brief interventions that target students' subjective experiences, were developed to address these issues. As a result, SPIs have been associated with gains in students' academic performance, attitude, and persistence in various instructional settings; however, only a limited number of studies have explored SPIs within a chemistry context. This study evaluated the effectiveness of two SPIs, a growth mindset intervention (GMI) and a utility value intervention (UVI), on promoting students' academic performance and attitude in a general chemistry course with a large class size. This study also explored a theoretical explanation for the relationship among SPIs, attitude, and academic performance. Each SPI was designed to facilitate instructional adoption and was implemented by posting three prompts incorporated into homework assignments. The results show that the UVI led to a consistent improvement in student achievement, and among students who begin the course with lower attitudes toward chemistry, the UVI led to an improvement in students' emotional satisfaction and utility value. The UVI's improvement in academic performance was also observed with a group of students who have been underrepresented in the sciences, although a smaller sample size prevented finding statistical significance. The GMI improved academic performance relative to a comparison group but not to the extent observed with the UVI. The cost-to-benefit ratio associated with adopting SPIs within chemistry instruction seems highly favorable and thus warrants strong consideration among chemistry instructors.

Conceptually understanding chemistry requires the ability to transition among representational levels to use an understanding of submicroscopic entities and properties to explain macroscopic phenomena. Past literature describes student struggles with these transitions but provides limited information about upper-level post-secondary chemistry students' abilities to transition among levels. This group is of particular interest as they are engaging in potentially their final training before entering a career as professional chemists, thus if students are likely to develop this skill during their formal education it should be manifest among this group. This study characterized analytical chemistry students' responses to open-ended assessments on acid--base titrations and thin-layer chromatography for the use of sub-microscopic entities or properties to explain these macroscopic phenomena. Further, to understand whether explanatory statements were an expectation inherent in the instructional context of the setting, the analytical chemistry instructor's lectures on acid--base titrations and thin-layer chromatography were analyzed with the same framework. The analysis found that students seldom invoked explanatory statements within their responses and that congruence between lectures and responses to assessment was primarily limited to the use of macroscopic, descriptive terms. Despite the fact that the lecture in class regularly invoked explanatory statements in one context, this did not translate to student use of explanatory statements. To further test the hypothesis that analytical chemistry students struggle with explanatory statements, a follow-on study was also conducted among a second cohort of students reviewing their responses when specifically prompted to use sub-microscopic entities to explain a macroscopic phenomenon. The results suggest that fewer than half of the students showed proficiency on generating explanatory statements when explicitly prompted to do so. Instructional implications to promote explanatory statements are proposed in the discussion.

This paper is designed to synopsize the efforts of a team of general chemistry teachers to enact assessments during the abrupt transition to online-only instruction and reflect on what was done successfully and what could be improved. The focus is on the extent remote, online assessments accurately measured student knowledge described within the context of the decisions made for administration of the assessments. To limit the extent of unintended student collaboration, exams were given at a set day and time; question banks were developed so that students received variants of similar questions, and a remote proctoring software was used. Correlations showed consistency between online exams and paper exams, alleviating concerns that widespread cheating may take place. A concern was found with reusing the same exam at a later date for students who missed the original exam despite efforts to keep the online exam secure. The generation of alternative exams for later dates is recommended, potentially supported by creating and curating an online repository of assessment items to utilize.

The submission of a traditional postgraduate research thesis (or dissertation) is a milestone achievement that should be celebrated and has been regarded as a rite of passage. This major document has normally occupied a significant amount of mental space and time, often involving a frantic and intense period of writing to meet the submission deadline. Immediately after submission, research supervisors inevitably turn their attention to thoughts of publications. Some students are fortunate and will have managed to generate several publications during their postgraduate research but for most this represents a daunting process. In recent years, speculation regarding a new paradigm for the PhD thesis and its examination has emerged. In many countries, including Europe and Australasia, there has been a shift towards integrating separate publications with conventional chapters to assemble a thesis or dissertation by publication, which is often referred to as a ''cumulative thesis or dissertation'' (Christianson et al., 2015; Mason and Merga, 2018; Frick, 2019). Regardless, the outcome is likely to be that students will be required to engage in the publication process at a much earlier point in their studies and thesis examination will require a different approach to evaluating the contribution of the candidate as an author. In chemistry education research, the traditional thesis structure is still a prevalent format so the process of converting a sometimes circuitous and very personal research journey into concise peer-reviewed articles requires careful consideration. In this article, the authors have brought together some thoughts from the editorial team to guide the process of publishing postgraduate research (PhD or Masters) in the "Chemistry Education Research and Practice" ("CERP"), being mindful that in the future, a different approach to mentoring novice authors in the process of publication may be necessary.

Calls for assessments incorporating representations beyond the symbolic level (e.g., chemical reactions and formulas) have encouraged assessment designers to choose from a variety of representations in the design of chemistry assessments. This work expands on prior work in considering how representations are incorporated within assessments. First, students were given assessment items similar in task with common rationales for the design of answer choices with different representations "substituted" across the items. Second, students were randomly assigned to items identical in prompt, answer choices, and symbolic representation with experimental items "supplementing" symbolic representation with particulate or mathematical representation. The impact was operationalized as student performance, the performance of at-risk chemistry students scoring in the bottom quartile of the cohort's standardized math test scores, and on the answer choices to which students attend. Substituting symbolic for particulate representation had a significant, negative impact on overall and at-risk student performance and a considerable impact on students' selection of distractors. However, supplementing symbolic with a particulate representation had no discernible impact. Supplementing symbolic representations with tables including a column for "moles" had a significant, positive impact on overall student performance with considerable improvement observed among at-risk students. Students' selection of a distractor representative of a failure to apply a mole-to-mole ratio was reduced when symbolic representations were supplemented with tables. Practical implications for the use of representations in a more equitable assessment design, and as a learning experience for students overall, are described.

The methodological limitations education researchers face in the evaluation of reformed instruction have led to debates as to the evidence advancing evidence-based practices. To conduct more effective research, methodological pluralism in the evaluation of educational reforms can be used to complement the strengths and limitations of a corpus of literature informing the impact of an evidence-based practice. This study seeks to introduce randomization tests, a nonparametric statistical analysis incorporating a random-assignment component that can be applied to a single-subject (N = 1) research design, as a methodology to be counted amongst evaluations of instructional reforms. To demonstrate the utility of this approach, an evaluation of peer-led team learning (PLTL) for classes of second-semester general chemistry spanning 7 semesters was conducted using randomization tests. The design contributes novel understandings of PLTL including differences in effectiveness across instructors, trends in effectiveness over time, and a perspective as to the appropriateness of assumptions concerning statistical independence when applied to educational settings. At the research setting, four instructors (each constituting an individual case) alternated implementing lecture-based instruction and PLTL by term. Across these four instructors, the treatment effects of peer-led team learning when compared to lecture-based instruction ranged in impact (from d = 0.233 to 2.09). For two instructors, PLTL provided a means by which to significantly reduce the differential performances observed of students with variable preparations in mathematics, thereby advancing the equitability of their courses. Implications of this work include the incorporation of single-subject research designs in establishing evidence-based instructional practices, the effectiveness of PLTL as interpreted in a methodologically pluralistic context of the research literature, and enacting measurements of equity when gauging the success of instructional reforms in science. Further, this introduction to randomization tests offers another methodology for the evaluation of instructional reforms more widely applicable in educational settings with smaller sample sizes ("e.g.," reforms conducted within a single classroom or upper-level courses with small class sizes).

Genome biology approaches have made enormous contributions to our understanding of biological rhythms, particularly in identifying outputs of the clock, including RNAs, proteins, and metabolites, whose abundance oscillates throughout the day. These methods hold significant promise for future discovery, particularly when combined with computational modeling. However, genome-scale experiments are costly and laborious, yielding "big data" that are conceptually and statistically difficult to analyze. There is no obvious consensus regarding design or analysis. Here we discuss the relevant technical considerations to generate reproducible, statistically sound, and broadly useful genome-scale data. Rather than suggest a set of rigid rules, we aim to codify principles by which investigators, reviewers, and readers of the primary literature can evaluate the suitability of different experimental designs for measuring different aspects of biological rhythms. We introduce CircaInSilico, a web-based application for generating synthetic genome biology data to benchmark statistical methods for studying biological rhythms. Finally, we discuss several unmet analytical needs, including applications to clinical medicine, and suggest productive avenues to address them.

Students who score within the bottom quartile on cognitive measures of math aptitude have been identified as at-risk for low performance in chemistry courses, with less attention as to "why" such differential performance persists. At-risk students struggle most differentially on assessment items related to the mole concept and stoichiometry. An exploration as to the nature of the differential performance observed became of great interest as the assessment of these topics rarely progresses beyond multiplication or division, and at-risk students who achieved proficiency with the mole concept and stoichiometry had no noticeable gaps in academic chemistry performance when compared to students scoring in the top three quartiles of math aptitude. Thus, students in first-semester general chemistry were surveyed to describe their solution processes toward assessment items involving the mole concept and stoichiometry. Three hundred and forty-eight students responded to all survey prompts with 101 identified as at-risk. Findings suggest that while all students were observed to struggle in the conceptualization of the algorithms by which they execute solution processes, not-at-risk chemistry students were more likely to achieve correct answers via chemically implausible solution pathways. Rather than suggest the removal of assessment practices involving algorithmic, multiple-choice assessment on these topics, the implications include practical suggestions and opportunities for further research toward improving the equitability of measures used to assess proficiency with stoichiometry.

Reproductive phasiRNAs (phased, small interfering RNAs) are broadly present in angiosperms and play crucial roles in sustaining male fertility. While the premeiotic 21-nt (nucleotides) phasiRNAs and meiotic 24-nt phasiRNA pathways have been extensively studied in maize (Zea mays) and rice (Oryza sativa), a third putative category of reproductive phasiRNAs-named premeiotic 24-nt phasiRNAs-have recently been reported in barley (Hordeum vulgare) and wheat (Triticum aestivum). To determine whether premeiotic 24-nt phasiRNAs are also present in maize and related species and begin to characterize their biogenesis and function, we performed a comparative transcriptome and degradome analysis of premeiotic and meiotic anthers from five maize inbred lines and three teosinte species/subspecies. Our data indicate that a substantial subset of the 24-nt phasiRNA loci in maize and teosinte are already highly expressed at the premeiotic phase. The premeiotic 24-nt phasiRNAs are similar to meiotic 24-nt phasiRNAs in genomic origin and dependence on DCL5 (Dicer-like 5) for biogenesis, however, premeiotic 24-nt phasiRNAs are unique in that they are likely i) not triggered by microRNAs, ii) not loaded by AGO18 proteins, and iii) not capable of mediating PHAS precursor cleavage. In addition, we also observed a group of premeiotic 24-nt phasiRNAs in rice using previously published data. Together, our results indicate that the premeiotic 24-nt phasiRNAs constitute a unique class of reproductive phasiRNAs and are present more broadly in the grass family (Poaceae) than previously known. [ABSTRACT FROM AUTHOR]

Introduction: The Strengths and Difficulties Questionnaire (SDQ) is one the most widely used behavior screening tools for public schools due to its strong psychometric properties, low cost, and brief (25-question) format. However, this screening tool has several limitations including being primarily developed for the purposes of identifying clinical diagnostic conditions and primarily in a European population. To date, there has been minimal comparative research on measurement invariance in relationship to important U.S. socio-demographic metrics such as race and gender. Method: This study utilized both structural equationmodeling (i.e., confirmatory factor analysis) and item response theory (IRT) methods to investigate the measurement invariance of the SDQ across gender (male, female) and race (Black, White). CFA analyses were first conducted for each of the SDQ subscales to identify potential misfit in loadings, thresholds, and residuals. IRT-graded response models were then conducted to identify and quantify the between-group differences at the item and factor levels in terms of Cohen's d styled metrics (d > 0.2 = small, d > 0.5 = medium, d > 8 = large). Results: There were 2,821 high school participants (52% Male, 48% Female; 88% Black, 12% White) included in these analyses. CFA analyses suggested that the item-factor relationship for most subscales were invariant, but the Conduct Problems and Hyperactivity subscales were non-invariant for strictmeasurement invariance. IRT analyses identified several invariant items ranging from small to large. Despite moderate to large effects for item scores on several scales, the test-level effects on scale scores were negligible. Discussion: These analyses suggest that the SDQ subscale scores display reasonable comparable item-factor relationships across groups. Several subscale item scores displayed substantive item-level misfit, but the test level effects were minimal. Implications for the field are discussed. [ABSTRACT FROM AUTHOR]

There has been an increased use of authentic practices in both science and environmental education in recent years. Such practices can utilize social constructivist frameworks to consider the learning that may be taking place as students become engaged in tool use. The current study focuses on a group of elementary school students studying the Everglades in the field and in a classroom setting during one academic year. In particular, we observed students' use of tools (identified as tool-conventions to include both artifacts and conventions) and compared their use in both settings. We found that in the field, students spent considerable amount of time engaged in data collection activity such as taking observations and measurements that resembled what scientists might be doing and included the invention of new tools to facilitate data gathering. In this context, students generally worked more independently from the teacher, collaborated in small work groups, and engaged in more self-directed inquiry. In the classroom, while some of the scientific field tools were practiced in anticipation of their use in the field, activity included more teacher direction, often resembling what might be found in other types of classroom work and the tools used there often supported this work. Models of tool use based on Yrjo Engestrom's activity approach were constructed for both settings. Implications of the results include the importance of viewing tool use in authentic learning with a sociocultural and activity perspective to reflect the socially constructed nature of such learning. (Contains 5 figures, 1 table, and 3 endnotes.)

The identification of students at risk for academic failure in undergraduate chemistry courses has been heavily addressed in the literature. Arguably one of the strongest and most well-supported predictors of undergraduate success in chemistry is the mathematics portion of the SAT (SAT-M), a college-entrance, standardized test administered by the College Board. While students scoring in the bottom quartile of the SAT-M (herein referred to as at-risk) perform significantly worse on first-semester chemistry assessments, little is known of the topics on which these students differentially struggle. The purpose of this study is to provide insight as to which first-semester chemistry topics present an incommensurate challenge to at-risk students. Students were identified as either at-risk or not at-risk via SAT-M scores. Students' assessment responses were collected across four semesters of first-semester chemistry courses at a large, public university (N = 5636). At-risk students struggled consistently across all topics but disproportionately with mole concept and stoichiometry. Analyzing the trend in topics suggests that the struggles of at-risk students are not entirely attributable to topics that rely heavily on algorithms or algebraic math. Moreso, at-risk students found to have performed well on mole concept and stoichiometry went on to perform similarly as their not at-risk peers. The results support an instructional emphasis on these topics with reviewed literature offering promising, practical options to better serve at-risk students and broaden representation in the sciences.

The Achievement Goal Framework describes students' goal orientations as: task-based, focusing on the successful completion of the task; self-based, evaluating performance relative to one's own past performance; or other-based, evaluating performance relative to the performance of others. Goal orientations have been used to explain student success in a range of educational settings, but have not been used in post-secondary chemistry. This study describes the goal orientations of General Chemistry students and explores the relationship of goal orientations to success in the course. On average, students report higher task and self orientations than other orientation. Task orientation had a positive relationship with exam performance and self orientation had a negative relationship with exam performance. Clustering students showed that for the majority of students task and self orientations moved concurrently and students with low preference across the three orientations also performed lowest on exams. Finally, students in classes using Flipped-Peer Led Team Learning, a pedagogy designed to bring active learning to a large lecture class, showed higher task orientation than those in classes with lecture-based instruction.

Mid-infrared optics require optical coatings composed of high- and low-refractive-index dielectric layers for the design of optical mirrors, filters, and anti-reflection coatings. However, there are not many technologies for depositing a material with a refractive index of less than 2 and a low loss in the mid-infrared region. Here, we present a unique deposition method of crosslinked polyethylene thin film for mid-IR optical filter design. Polyethylene has a refractive index of 1.52 in the mid-infrared region and a small number of absorption peaks, so it is useful for making optical filters in the mid-infrared region. Only 1 keV of energy is required to crosslink the entire film by irradiating an electron beam while depositing polyethylene. In addition, crosslinked polyethylene thin film has high mechanical strength, so there is no cracking or peeling when used with germanium. This allows for the use of crosslinked polyethylene as a low refractive index for mid-infrared optical coating. [ABSTRACT FROM AUTHOR]

Meta-analysis can provide a robust description of the impact of educational reforms and also offer an opportunity to explore the conditions where such reforms are more or less effective. This article describes a meta-analysis on the impact of cooperative learning on students' chemistry understanding. Modifiers in the meta-analysis are purposefully chosen to model instructors' decisions in implementing cooperative learning. Modifiers investigated include: using cooperative learning periodically or in every class period; setting a maximum group size at four or smaller versus five or larger; using closed-ended or open-ended assessments; and assessing a single topic or assessing the cumulative topics in the course. The results showed cooperative learning's effectiveness is robust across a wide range of instructional decisions except no evidence of effectiveness was found with cumulative assessments. The overall results from the meta-analysis provide a benchmark for evaluating future efforts to evaluate pedagogical interventions in chemistry.

The research-based pedagogical strategy of flipped classes has been shown to be effective for increasing student achievement and retention in postsecondary chemistry classes. The purpose of flipped classes is to move content delivery (e.g., lecture) outside of the classroom, freeing more face-to-face time for active learning strategies. The opportunity to engage in active learning with students can be a challenge for instructors of large classes (more than 100 students). Furthermore, there has been little discussion in the chemical education literature to provide instructors with detailed descriptions of successful implementations of flipped classes combined with active learning in large classes. To this end, this report provides a comprehensive description and evaluation of a coordinated implementation of flipped classes with peer-led team learning (PLTL) for second-semester general chemistry with class sizes greater than 200 students. This approach is described as "Flipped PLTL." This report includes details about creation of videos for flipped instruction, class structure, and the recruiting and training of peer leaders. The purpose of this paper is to provide an example of flipped classes with PLTL that can guide other instructors who wish to implement these pedagogies in large classes.

A well-established literature base identifies a portion of students enrolled in post-secondary General Chemistry as at-risk of failing the course based on incoming metrics. Learning about the experiences and factors that lead to this higher failure rate is essential toward improving retention in this course. This study examines the relationship between study habits and academic performance for at-risk students in General Chemistry. Students who were in the bottom quartile of SAT math scores were identified as at-risk students. The study habits of General Chemistry students, both those identified as at-risk and those not identified were measured by text message inquiries. The text message asked ''Have you studied for General Chemistry I in the past 48 hours? If so, how did you study?'' twice a week throughout a semester. Student responses to the messages were used to calculate the frequency of studying throughout the term. The results from a multiple regression analysis showed that high frequency of studying could mitigate the difference between at-risk and non-at-risk students on final exam scores. Additionally, the quality of studying for six at-risk students was analyzed by student interviews in concert with their text message responses. The results indicated that the quality of studying is not necessarily linked to frequency of studying and both quality and frequency can play a role in at-risk students' academic performance. The results presented offer a path for at-risk students to succeed in General Chemistry and the methodology presented offers a potential avenue for evaluating future efforts to improve student success.

Spiral jet mills are ubiquitous in the pharmaceutical industry. Breakage and classification in spiral jet mills occur due to complex interactions between the fluid and the solid phases. The study of these interactions requires the use of computational fluid dynamics (CFD) for the fluid phase coupled with discrete element models (DEM) for the particle phase. In this study, we investigate particle dynamics in a 50-mm spiral jet mill through coupled CFD-DEM simulations. The simulations showed that the fluid was significantly decelerated by the presence of the particles in the milling chamber. Furthermore, we study the particle dynamics and collision statistics at two different operating conditions and three different particle loadings. As expected, the particle velocity was affected by both the particle loading and operating pressure. The particles moved slower at low pressures and high loadings. We also found that particle–particle collisions outnumbered particle–wall collisions.