Getting Under the Hood: How and for Whom Does Increasing Course Structure Work?

The authors explore the transferability of an active-learning intervention and expand upon the original studies by 1) disaggregating student populations to identify for whom the intervention works best and 2) exploring possible proximate mechanisms (changes in student behaviors and perceptions) that could mediate the observed increase in achievement.At the college level, the effectiveness of active-learning interventions is typically measured at the broadest scales: the achievement or retention of all students in a course. Coarse-grained measures like these cannot inform instructors about an intervention's relative effectiveness for the different student populations in their classrooms or about the proximate factors responsible for the observed changes in student achievement. In this study, we disaggregate student data by racial/ethnic groups and first-generation status to identify whether a particular intervention—increased course structure—works better for particular populations of students. We also explore possible factors that may mediate the observed changes in student achievement. We found that a “moderate-structure” intervention increased course performance for all student populations, but worked disproportionately well for black students—halving the black–white achievement gap—and first-generation students—closing the achievement gap with continuing-generation students. We also found that students consistently reported completing the assigned readings more frequently, spending more time studying for class, and feeling an increased sense of community in the moderate-structure course. These changes imply that increased course structure improves student achievement at least partially through increasing student use of distributed learning and creating a more interdependent classroom community

Inclusion in neuroscience through high impact courses

Recognizing that STEM disciplines, including neuroscience, have a long way to go to attract and retain diverse talent, educators can take action by being more intentional about their departmental curricula, course design, and pedagogical strategies. A deep body of research suggests that one way we can promote inclusion is through the use of high impact practices (HIPs). These active learning teaching practices promote deep learning and student engagement and have been shown to have a positive differential impact on historically underserved student populations. Here we describe the characteristics of two different types of HIP courses, makerspace classes, and course-based undergraduate research experiences (CUREs). In addition, we provide ideas for how these courses can be structured to help all students engage and learn. With experience overseeing a large campus-wide program introducing these course types to the curriculum, we also provide insights about faculty experiences and assessment. We propose that including these types of courses in a curriculum can engage a more diverse group of students to choose neuroscience as a major and as a career

Seal Occurrence and Habitat Use during Summer in Petermann Fjord, Northwestern Greenland

Ice-associated seals are considered especially susceptible and are potentially the first to modify distribution and habitat use in response to physical changes associated with the changing climate. Petermann Glacier, part of a unique ice-tongue fjord environment in a rarely studied region of northwestern Greenland, lost substantial sections of its ice tongue during major 2010 and 2012 calving events. As a result, changes in seal habitat may have occurred. Seal occurrence and distribution data were collected in Petermann Fjord and adjacent Nares Strait region over 27 days (2 to 28 August) during the multidisciplinary scientific Petermann 2015 Expedition on the icebreaker Oden. During 239.4 hours of dedicated observation effort, a total of 312 individuals were recorded, representing four species: bearded seal (Erignathus barbatus), hooded seal (Crystophora cristata), harp seal (Pagophilus groenlandicus), and ringed seal (Pusa hispida). Ringed seals were recorded significantly more than the other species (χ2 = 347.4, df = 3, p < 0.001, n = 307). We found significant differences between species in haul-out (resting on ice) behavior (χ2 = 133.1, df = 3, p < 0.001, n = 307). Bearded seals were more frequently hauled out (73.1% n = 49), whereas ringed seals were almost exclusively in water (93.9%, n = 200). Differences in average depth and ice coverage where species occurred were also significant: harp seals and bearded seals were found in deeper water and areas of greater ice coverage (harp seals: 663 ± 366 m and 65 ± 14% ice cover; bearded seals: 598 ± 259 m and 50 ± 21% ice cover), while hooded seals and ringed seals were found in shallower water with lower ice coverage (hooded seals: 490 ± 163 m and 38 ± 19% ice cover; ringed seals: 496 ± 235 m, and 21 ± 20% ice cover). Our study provides an initial look at how High Arctic seals use the rapidly changing Petermann Fjord and how physical variables influence their distribution in one of the few remaining ice-tongue fjord environments.Les phoques associés aux glaces sont considérés comme très susceptibles et sont potentiellement les premiers à modifier la répartition de leur population et la façon dont ils utilisent leur habitat en réponse aux changements physiques découlant des changements climatiques. Le glacier Petermann fait partie d’une langue glaciaire de fjord unique dans une région rarement étudiée du nord-ouest du Groenland. De gros blocs de glace se sont détachés du glacier Petermann pendant le vêlage de 2010 à 2012. Par conséquent, l’habitat des phoques aurait pu être modifié. Pendant 27 jours (du 2 au 28 août), des données sur la présence et la répartition des phoques ont été recueillies au fjord Petermann et dans la région adjacente du détroit de Nares dans le cadre de l’expédition scientifique multidisciplinaire Petermann 2015 sur le brise-glace Oden. Au cours de 239,4 heures d’observation soutenue, la présence d’un total de 312 phoques représentant quatre espèces a été notée : le phoque barbu (Erignathus barbatus), le phoque à capuchon (Crystophora cristata), le phoque du Groenland (Pagophilus groenlandicus) et le phoque annelé (Pusa hispida). La présence de phoques annelés est considérablement plus importante que celle des autres espèces (χ2 = 347,4, ddl = 3, p < 0,001, n = 307). Nous avons constaté une différence significative dans les comportements d’échouerie (repos sur la glace) des phoques selon les espèces (χ2 = 133,11, ddl = 3, p < 0,001, n = 307). Les phoques barbus étaient plus souvent hors de l’eau (73,1 %, n = 49), tandis que les phoques annelés se trouvaient presque exclusivement dans l’eau (93,9 %, n = 200). Des différences significatives en ce qui a trait à la présence des espèces selon la profondeur et la couverture glaciaire ont été notées. Les phoques du Groenland et les phoques barbus fréquentent les profondeurs d’eau moyennes (663 ± 366 m et 598 ± 259 m, respectivement) et les régions où la couverture de glace correspond à la moyenne supérieure (65 ± 14 % et 50 ± 21 %, respectivement), tandis que les phoques à capuchon et les phoques annelés fréquentent les eaux moins profondes (490 ± 163 m et 496 ± 235 m, respectivement) et les régions où la couverture de glace correspond à la moyenne inférieure (38 ± 19 % et 21 ± 20, respectivement). Notre étude présente un premier aperçu de la façon dont les phoques de l’Extrême-Arctique utilisent le fjord Petermann en évolution rapide et de l’influence des variables physiques sur leur répartition dans l’une des rares langues glaciaires de fjord restantes

The Multi-faceted Ecto-enzyme CD38: Roles in Immunomodulation, Cancer, Aging, and Metabolic Diseases

CD38 (Cluster of Differentiation 38) is a multifunctional ecto-enzyme that metabolizes NAD+ and mediates nicotinamide dinucleotide (NAD+) and extracellular nucleotide homeostasis as well as intracellular calcium. CD38 is also an emerging therapeutic target under conditions in which metabolism is altered including infection, aging, and tumorigenesis. We describe multiple enzymatic activities of CD38, which may explain the breadth of biological roles observed for this enzyme. Of greatest significance is the role of CD38 as an ecto-enzyme capable of modulating extracellular NAD+ precursor availability: 1 to bacteria unable to perform de novo synthesis of NAD+; and 2 in aged parenchyma impacted by the accumulation of immune cells during the process of ‘inflammaging’. We also discuss the paradoxical role of CD38 as a modulator of intracellular NAD+, particularly in tumor immunity. Finally, we provide a summary of therapeutic approaches to CD38 inhibition and ‘NAD+ boosting’ for treatment of metabolic dysfunction observed during aging and in tumor immunity. The present review summarizes the role of CD38 in nicotinamide nucleotide homeostasis with special emphasis on the role of CD38 as an immunomodulator and druggable target

The Holocene retreat dynamics and stability of Petermann Glacier in northwest Greenland

Submarine glacial landforms in fjords are imprints of the dynamic behaviour of marine-terminating glaciers and are informative about their most recent retreat phase. Here we use detailed multibeam bathymetry to map glacial landforms in Petermann Fjord and Nares Strait, northwestern Greenland. A large grounding-zone wedge (GZW) demonstrates that Petermann Glacier stabilised at the fjord mouth for a considerable time, likely buttressed by an ice shelf. This stability was followed by successive backstepping of the ice margin down the GZW’s retrograde backslope forming small retreat ridges to 680 m current depth (∼730–800 m palaeodepth). Iceberg ploughmarks occurring somewhat deeper show that thick, grounded ice persisted to these water depths before final breakup occurred. The palaeodepth limit of the recessional moraines is consistent with final collapse driven by marine ice cliff instability (MICI) with retreat to the next stable position located underneath the present Petermann ice tongue, where the seafloor is unmapped

Live imaging molecular changes in junctional tension upon VE-cadherin in zebrafish

Forces play diverse roles in vascular development, homeostasis and disease. VE-cadherin at endothelial cell-cell junctions links the contractile acto-myosin cytoskeletons of adjacent cells, serving as a tension-transducer. To explore tensile changes across VE-cadherin in live zebrafish, we tailored an optical biosensor approach, originally established in vitro. We validate localization and function of a VE-cadherin tension sensor (TS) in vivo. Changes in tension across VE-cadherin observed using ratio-metric or lifetime FRET measurements reflect acto-myosin contractility within endothelial cells. Furthermore, we apply the TS to reveal biologically relevant changes in VE-cadherin tension that occur as the dorsal aorta matures and upon genetic and chemical perturbations during embryonic development

Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland

Petermann Fjord is a deep (>1000 m) fjord that incises the coastline of north-west Greenland and was carved by an expanded Petermann Glacier, one of the six largest outlet glaciers draining the modern Greenland Ice Sheet (GrIS). Between 5 and 70 m of unconsolidated glacigenic material infills in the fjord and adjacent Nares Strait, deposited as the Petermann and Nares Strait ice streams retreated through the area after the Last Glacial Maximum. We have investigated the deglacial deposits using seismic stratigraphic techniques and have correlated our results with high-resolution bathymetric data and core lithofacies. We identify six seismo-acoustic facies in more than 3500 line kilometres of sub-bottom and seismic-reflection profiles throughout the fjord, Hall Basin and Kennedy Channel. Seismo-acoustic facies relate to bedrock or till surfaces (Facies I), subglacial deposition (Facies II), deposition from meltwater plumes and icebergs in quiescent glacimarine conditions (Facies III, IV), deposition at grounded ice margins during stillstands in retreat (grounding-zone wedges; Facies V) and the redeposition of material downslope (Facies IV). These sediment units represent the total volume of glacial sediment delivered to the mapped marine environment during retreat. We calculate a glacial sediment flux for the former Petermann ice stream as 1080–1420 m3 a−1 per metre of ice stream width and an average deglacial erosion rate for the basin of 0.29–0.34 mm a−1. Our deglacial erosion rates are consistent with results from Antarctic Peninsula fjord systems but are several times lower than values for other modern GrIS catchments. This difference is attributed to fact that large volumes of surface water do not access the bed in the Petermann system, and we conclude that glacial erosion is limited to areas overridden by streaming ice in this large outlet glacier setting. Erosion rates are also presented for two phases of ice retreat and confirm that there is significant variation in rates over a glacial–deglacial transition. Our new glacial sediment fluxes and erosion rates show that the Petermann ice stream was approximately as efficient as the palaeo-Jakobshavn Isbræ at eroding, transporting and delivering sediment to its margin during early deglaciation