Keynote Address - Promising Practices in Undergraduate Science Education: Why Don’t We Implement Them?

Improving undergraduate science education for all students is a national imperative in the US, called out in many recent reports, including the President’s Council of Advisors on Science and Technology’s (PCAST) Engage to Excel. Globally, we face profound challenges to provide adequate resources to a growing human population in the face of climate change, pollution, and loss of biodiversity that can be addressed, in part, by scientists, engineers, and a scientifically literate society. Undergraduate science education serves a range of purposes from providing foundational knowledge for all students, to preparing the future teachers, to preparing a STEM workforce. A shortage of STEM workers is predicted in the coming decade and improving retention of undergraduate STEM majors through improved STEM education in the first two years of university is a solution called out in the PCAST report. The National Research Council’s Discipline-based Education Research: Understanding and Improving Learning in Undergraduate Science and Engineering report provides the evidence base for effective teaching practices in undergraduate programs. This presentation will explore what is known about improving students’ problem solving skills and conceptual understanding in science through more effective teaching and then unpack the challenges to widespread uptake of these practices

From Observers to Participants: Joining the Scientific Community

In this essay, we have integrated the voices of our mentors and students to explore 45 years of undergraduate research experiences and their role in shaping our scientific community. In considering our collective experiences, we see undergraduate involvement in research as a rich source of community development, one that has both touched our lives and influenced our teaching

Nonequivalent effects of PKC activation by PMA on murine CD4 and CD8 cell‐surface expression

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154260/1/fsb2002012010.pd

Photometry of Kuiper belt object (486958) Arrokoth from New Horizons LORRI

On January 1st 2019, the New Horizons spacecraft flew by the classical Kuiper belt object (486958) Arrokoth (provisionally designated 2014 MU69), possibly the most primitive object ever explored by a spacecraft. The I/F of Arrokoth is analyzed and fit with a photometric function that is a linear combination of the Lommel-Seeliger (lunar) and Lambert photometric functions. Arrokoth has a geometric albedo of p_v = 0.21_(−0.04)^(+0.05) at a wavelength of 550 nm and ≈0.24 at 610 nm. Arrokoth's geometric albedo is greater than the median but consistent with a distribution of cold classical Kuiper belt objects whose geometric albedos were determined by fitting a thermal model to radiometric observations. Thus, Arrokoth's geometric albedo adds to the orbital and spectral evidence that it is a cold classical Kuiper belt object. Maps of the normal reflectance and hemispherical albedo of Arrokoth are presented. The normal reflectance of Arrokoth's surface varies with location, ranging from ≈0.10–0.40 at 610 nm with an approximately Gaussian distribution. Both Arrokoth's extrema dark and extrema bright surfaces are correlated to topographic depressions. Arrokoth has a bilobate shape and the two lobes have similar normal reflectance distributions: both are approximately Gaussian, peak at ≈0.25 at 610 nm, and range from ≈0.10–0.40, which is consistent with co-formation and co-evolution of the two lobes. The hemispherical albedo of Arrokoth varies substantially with both incidence angle and location, the average hemispherical albedo at 610 nm is 0.063 ± 0.015. The Bond albedo of Arrokoth at 610 nm is 0.062 ± 0.015

Polyploidy Did Not Predate the Evolution of Nodulation in All Legumes

BACKGROUND: Several lines of evidence indicate that polyploidy occurred by around 54 million years ago, early in the history of legume evolution, but it has not been known whether this event was confined to the papilionoid subfamily (Papilionoideae; e.g. beans, medics, lupins) or occurred earlier. Determining the timing of the polyploidy event is important for understanding whether polyploidy might have contributed to rapid diversification and radiation of the legumes near the origin of the family; and whether polyploidy might have provided genetic material that enabled the evolution of a novel organ, the nitrogen-fixing nodule. Although symbioses with nitrogen-fixing partners have evolved in several lineages in the rosid I clade, nodules are widespread only in legume taxa, being nearly universal in the papilionoids and in the mimosoid subfamily (e.g., mimosas, acacias)--which diverged from the papilionoid legumes around 58 million years ago, soon after the origin of the legumes. METHODOLOGY/PRINCIPAL FINDINGS: Using transcriptome sequence data from Chamaecrista fasciculata, a nodulating member of the mimosoid clade, we tested whether this species underwent polyploidy within the timeframe of legume diversification. Analysis of gene family branching orders and synonymous-site divergence data from C. fasciculata, Glycine max (soybean), Medicago truncatula, and Vitis vinifera (grape; an outgroup to the rosid taxa) establish that the polyploidy event known from soybean and Medicago occurred after the separation of the mimosoid and papilionoid clades, and at or shortly before the Papilionoideae radiation. CONCLUSIONS: The ancestral legume genome was not fundamentally polyploid. Moreover, because there has not been an independent instance of polyploidy in the Chamaecrista lineage there is no necessary connection between polyploidy and nodulation in legumes. Chamaecrista may serve as a useful model in the legumes that lacks a paleopolyploid history, at least relative to the widely studied papilionoid models

High-throughput isolation and characterization of untagged membrane protein complexes: outer membrane complexes of Desulfovibrio vulgaris.

Cell membranes represent the "front line" of cellular defense and the interface between a cell and its environment. To determine the range of proteins and protein complexes that are present in the cell membranes of a target organism, we have utilized a "tagless" process for the system-wide isolation and identification of native membrane protein complexes. As an initial subject for study, we have chosen the Gram-negative sulfate-reducing bacterium Desulfovibrio vulgaris. With this tagless methodology, we have identified about two-thirds of the outer membrane- associated proteins anticipated. Approximately three-fourths of these appear to form homomeric complexes. Statistical and machine-learning methods used to analyze data compiled over multiple experiments revealed networks of additional protein-protein interactions providing insight into heteromeric contacts made between proteins across this region of the cell. Taken together, these results establish a D. vulgaris outer membrane protein data set that will be essential for the detection and characterization of environment-driven changes in the outer membrane proteome and in the modeling of stress response pathways. The workflow utilized here should be effective for the global characterization of membrane protein complexes in a wide range of organisms

Metabolic Health Reduces Risk of Obesity-Related Cancer in Framingham Study Adults

Abstract Background: It is unknown whether the risk for obesity-related cancers differs between metabolically unhealthy and healthy overweight/obese adults. Methods: Data on body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and random blood glucose in Framingham Heart Study adults (n ¼ 3,763) ages 55 to 69 years were used to estimate risks of obesity-related cancers (n ¼ 385), including postmenopausal breast, female reproductive, colon, liver, gallbladder, pancreas, and kidney cancers, as well as esophageal adenocarcinomas. Multivariable-adjusted Cox proportional hazards models were used to estimate risk for obesity-related cancers associated with body fat and metabolic health (as defined by glucose levels) among subjects in three risk groups (vs. referent group with normal weight/normal glucose): normal weight/elevated glucose, overweight/normal glucose, and overweight/elevated glucose. Results: Overweight adults [BMI 25 or WHtR 0.51 (men) and 0.57 (women)] with elevated glucose (125 mg/dL) had a statistically significant 2-fold increased risk of developing obesity-related cancer, whereas overweight adults with normal glucose had a 50% increased risk. Normal-weight adults with elevated glucose had no excess cancer risk. The effects of BMI and WHtR were independent of one another. Finally, overweight women with elevated blood glucose had a 2.6-fold increased risk [95% confidence interval (CI), 1.4-4.9] of female reproductive (cervical, endometrial, uterine cancers) and postmenopausal breast cancers, whereas overweight women with normal glucose levels had only a 70% increased risk (95% CI, 1.1-2.5). Conclusion: These results suggest that cancer risk may be lower among metabolically healthy overweight/ obese older adults than among overweight/obese adults with metabolic dysfunction. Impact: Metabolic dysfunction and obesity act synergistically to increase cancer risk. Cancer Epidemiol Biomarkers Prev; 23(10); 2057-65. Ó2014 AACR

Photometry of Kuiper belt object (486958) Arrokoth from New Horizons LORRI

On January 1st 2019, the New Horizons spacecraft flew by the classical Kuiper belt object (486958) Arrokoth (provisionally designated 2014 MU69), possibly the most primitive object ever explored by a spacecraft. The I/F of Arrokoth is analyzed and fit with a photometric function that is a linear combination of the Lommel-Seeliger (lunar) and Lambert photometric functions. Arrokoth has a geometric albedo of p_v = 0.21_(−0.04)^(+0.05) at a wavelength of 550 nm and ≈0.24 at 610 nm. Arrokoth's geometric albedo is greater than the median but consistent with a distribution of cold classical Kuiper belt objects whose geometric albedos were determined by fitting a thermal model to radiometric observations. Thus, Arrokoth's geometric albedo adds to the orbital and spectral evidence that it is a cold classical Kuiper belt object. Maps of the normal reflectance and hemispherical albedo of Arrokoth are presented. The normal reflectance of Arrokoth's surface varies with location, ranging from ≈0.10–0.40 at 610 nm with an approximately Gaussian distribution. Both Arrokoth's extrema dark and extrema bright surfaces are correlated to topographic depressions. Arrokoth has a bilobate shape and the two lobes have similar normal reflectance distributions: both are approximately Gaussian, peak at ≈0.25 at 610 nm, and range from ≈0.10–0.40, which is consistent with co-formation and co-evolution of the two lobes. The hemispherical albedo of Arrokoth varies substantially with both incidence angle and location, the average hemispherical albedo at 610 nm is 0.063 ± 0.015. The Bond albedo of Arrokoth at 610 nm is 0.062 ± 0.015

Assessing exposure in epidemiologic studies to disinfection by-products in drinking water: report from an international workshop.

The inability to accurately assess exposure has been one of the major shortcomings of epidemiologic studies of disinfection by-products (DBPs) in drinking water. A number of contributing factors include a) limited information on the identity, occurrence, toxicity, and pharmacokinetics of the many DBPs that can be formed from chlorine, chloramine, ozone, and chlorine dioxide disinfection; b) the complex chemical interrelationships between DBPs and other parameters within a municipal water distribution system; and c) difficulties obtaining accurate and reliable information on personal activity and water consumption patterns. In May 2000, an international workshop was held to bring together various disciplines to develop better approaches for measuring DBP exposure for epidemiologic studies. The workshop reached consensus about the clear need to involve relevant disciplines (e.g., chemists, engineers, toxicologists, biostatisticians and epidemiologists) as partners in developing epidemiologic studies of DBPs in drinking water. The workshop concluded that greater collaboration of epidemiologists with water utilities and regulators should be encouraged in order to make regulatory monitoring data more useful for epidemiologic studies. Similarly, exposure classification categories in epidemiologic studies should be chosen to make results useful for regulatory or policy decision making