Colorado College
  • Colorado Springs, CO, United States
Recent publications
Social media use is pervasive among youth and is associated with body image disturbance and self-objectification. The present study investigated whether a 3-day social media fast in a sample for whom social media is especially salient, female adolescent dancers, can mitigate such negative effects. Through an online survey, 65 pre-teen and teen girls, aged 10–19, completed measures of self-objectification (body surveillance and body shame), self-esteem and self-compassion both prior to and following three days of abstaining from all social media. During the fast, girls reflected on their experiences in group messages on the messaging app, WhatsApp. Overall, the fast had positive effects on participants, for whom body surveillance and body shame was significantly reduced after the fast. Self-compassion significantly mediated the change in both body surveillance and body shame, and self-esteem was a significant mediator of improvements in body shame. The content of girls’ group messages revealed a number of themes, such as more positive mental states during the fast. Future research should continue to examine the potential of brief social media fasts as a means to alleviate appearance pressures adolescent girls face on these platforms in daily life.
Clinical assessments of movement disorders currently rely on the administration of rating scales, which, while clinimetrically validated and reliable, rely on clinicians’ subjective analyses, resulting in interrater differences. Intraoperative microelectrode recording for deep brain stimulation targeting similarly relies on clinicians’ subjective evaluations of movement-related neural activity. Digital motion tracking can improve the diagnosis, assessment, and treatment of movement disorders by generating objective, standardized measures of patients’ kinematics. Motion tracking with concurrent neural recording also enables motor neuroscience studies to elucidate the neurophysiology underlying movements. Despite these promises, motion tracking has seen limited adoption in clinical settings due to the drawbacks of conventional motion tracking systems and practical limitations associated with clinical settings. However, recent advances in deep learning based computer vision algorithms have made accurate, robust markerless motion. tracking viable in any setting where digital video can be captured. Here, we review and discuss the potential clinical applications and technical limitations of deep learning based markerless motion tracking methods with a focus on DeepLabCut (DLC), an open-source software package that has been extensively applied in animal neuroscience research. We first provide a general overview of DLC, discuss its present usage, and describe the advantages that DLC confers over other motion tracking methods for clinical use. We then present our preliminary results from three ongoing studies that demonstrate the use of DLC for 1) movement disorder patient assessment and diagnosis, 2) intraoperative motor mapping for deep brain stimulation targeting and 3) intraoperative neural and kinematic recording for basic human motor neuroscience.
The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are the closest massive satellite galaxies of the Milky Way. They are probably on their first passage on an infalling orbit towards our Galaxy¹ and trace the continuing dynamics of the Local Group². Recent measurements of a high mass for the LMC (Mhalo ≈ 1011.1–11.4 M⊙)3–6 imply that the LMC should host a Magellanic Corona: a collisionally ionized, warm-hot gaseous halo at the virial temperature (105.3–5.5 K) initially extending out to the virial radius (100–130 kiloparsecs (kpc)). Such a corona would have shaped the formation of the Magellanic Stream⁷, a tidal gas structure extending over 200° across the sky2,8,9 that is bringing in metal-poor gas to the Milky Way¹⁰. Here we show evidence for this Magellanic Corona with a potential direct detection in highly ionized oxygen (O⁺⁵) and indirectly by means of triply ionized carbon and silicon, seen in ultraviolet (UV) absorption towards background quasars. We find that the Magellanic Corona is part of a pervasive multiphase Magellanic circumgalactic medium (CGM) seen in many ionization states with a declining projected radial profile out to at least 35 kpc from the LMC and a total ionized CGM mass of log10(MH II,CGM/M⊙) ≈ 9.1 ± 0.2. The evidence for the Magellanic Corona is a crucial step forward in characterizing the Magellanic group and its nested evolution with the Local Group.
Quantifying reproductive effort (RE), the trade-off between devoting resources to reproduction versus individual growth, in plants presents a number of challenges. Of particular interest is comparing RE between reproductive strategies, such as those in Bromeliaceae: semelparous, where individuals undergo a one-time and subsequently lethal sexual reproductive event, versus iteroparous, where individuals reproduce sexually multiple times by producing clonal offshoots called pups. We introduce a dynamic model of vegetative and reproductive growth in long-lived Bromeliaceae rosettes accounting for the allocation of resources over developmental time. We compare multiple definitions of RE in semelparous and iteroparous Bromeliaceae at critical times during development and over the entire reproductive life of the individual. While others have posited that semelparous taxa exhibit higher RE than comparable iteroparous taxa, our results indicate this will only occur in limited circumstances: when RE is calculated over the lifespan of a rosette started from seed, semelparous RE is greater when pup mass is accounted for as if it were purely vegetative; or when RE is calculated over the lifespan of the genetic individual, semelparous RE is greater when the ratio of vegetative to inflorescence mass in each pup is greater than that of the originating rosette started from seed.
One of the most difficult aspects of studying intact amphibian communities is that they tend to occupy isolated areas within inaccessible terrain—factors that both protect watersheds from development and disturbance while also making them difficult to study. We conducted an extensive survey of the freshwater herpetofauna of the remote King Range National Conservation Area in Northern California using a combination of visual encounter surveys and environmental DNA (eDNA) sampling. We found twelve species of native aquatic amphibians and the western pond turtle (Actinemys marmorata), and no introduced amphibians. Detection probabilities for the four most commonly encountered species, giant salamanders (Dicamptodon sp), foothill yellow-legged frogs (Rana boylii), western toads (Anaxyrus boreas), and black salamanders (Aneides flavipunctatus), were affected by substrate and canopy cover, but the effects of these habitat characteristics on detection probability were species specific. Neither survey method, visual encounter surveys nor eDNA sampling, was more effective than the other, and our study suggests that the use of visual encounter surveys in conjunction with eDNA sampling may counteract the shortcomings of either when done individually. Five species were found using both methods, seven were only encountered during visual encounter surveys, and one recorded only from eDNA sampling. DNA samples from two taxa, toads and giant salamanders, could not be resolved to species. Toad species identity was assigned to the only member of the candidate species with a species range known to overlap the study area; the other three candidate species occupy restricted ranges far from the study area. Neither of the two giant salamander candidate species have known species ranges overlapping the study area. One, the California giant salamander (D. ensata), is known to occur within 100 km. However, there is a paucity of genetic material in GenBank DNA library for both the California giant salamander and the coastal giant salamander (D. tenebrosus), a widely distributed species with a range overlapping the study area, which could lead to inaccurate assignment of eDNA fragments.
This paper presents a novel tendon-driven soft prosthetic hand with 5 fingers and 9 independent actuators. A special notched structure was used as the finger joint, which brings adequate compliance to grasping. The soft finger has two kinds of vertically arranged joints that can produce flexion/extension and abduction/adduction motions under tension and release, enabling a three-dimensional workspace of the finger and improving the dexterity of the hand. The design and manufacture of the finger and soft hand are described in detail. An open-loop kinematic model based on piecewise constant curvature of the finger was established and verified experimentally. The results show that the model could precisely predict finger movement. The slip resistance of the soft hand was tested, and the capacity to grasp objects was evaluated based on power grasp and precision grasp. With abduction joints, the proposed hand can perform various gestures and in-hand manipulations, which indicate high dexterity. This work provides a way to realize high dexterity for soft prosthetic hands.
Personality variables, including sensation-seeking, interpersonal trust, avoidance of uncertainty, endorsement of social conformity, and love styles (Ludus, Eros, Pragma, Storge, Mania, and Agape), were examined as predictors of prejudicial attitudes toward individuals who practice polyamory and personal interest in engaging in consensual non-monogamy (CNM) among 1831 participants who completed anonymous surveys online. Personality characteristics were also compared between individuals who currently practice CNM (n = 67) and case-matched controls involved in monogamous relationships. As predicted, prejudicial attitudes and willingness to engage in CNM were positively and moderately correlated and there was substantial overlap in the predictors of both variables. However, the strongest predictors differed: prejudicial attitudes were best predicted, in a positive direction, by endorsement of social conformity and, to a lesser extent, Pragma love style, while willingness to engage in CNM was best predicted by the Ludus (positive) and Eros (negative) love styles. Individuals who practice monogamy and CNM were more similar than different: only two of the 12 variables tested significantly differed. CNM individuals are more ludic and more tolerant of cognitive uncertainty. Difficulty interpreting some of the results laid bare the need for relationship measures that are valid for individuals who practice CNM. Improving our understanding of the relation between personality traits and CNM may help us develop better interventions for clients who seek to transition from monogamy to CNM but struggle to adapt to the new challenges as well as design better efforts to increase acceptance and reduce discrimination against those who practice CNM.
Understanding how mud moves and deposits is essential for conceptualizing the dynamic nature of surface environments and their ancient counterparts. Experimental study has largely been pursued by civil engineers, using kaolinite as an active ingredient. Yet, applying their data to the physical comprehension of mudstone sedimentology is hampered by multiple flume configurations between labs, and data sets tailored to specific engineering needs. The need for a better grasp of underlying processes is acute, given recent flume studies that show that moving suspensions form large bedload floccules, migrating floccule ripples and bed accretion under currents capable of moving sand grains. To advance mudstone sedimentology, integrated study of suspended sediment concentration, salinity and bed shear stress on the deposition of floccules is crucial. Described here is a set of tightly controlled experiments that explored suspended sediment concentrations from 70 to 900 mg/l, freshwater, brackish and marine salinities, flow velocities in the 5 to 50 cm/s range (equivalent to 0.01 to 0.58 Pa bed shear), measured the size of in‐flow and bedload floccules, and the critical velocity of sedimentation that marks the onset of sustained bedload accumulation. The critical velocity of sedimentation of kaolinite clays is in the 26 to 28 cm/s flow velocity range (0.22 to 0.25 Pa), appears insensitive to a wide range of suspended sediment concentrations and salinities, and coincides with the formation of sand‐size bedload floccules. Further decrease of flow velocity/bed shear stress is accompanied by a steady increase in the size of bedload floccules. Large bedload floccules appear to form in the high‐shear basal part of the flow, a phenomenon requiring further investigation. Better understanding of the mechanisms that facilitate mud deposition from moving suspensions is critical for more realistic assessments of the depositional conditions of mud and mudstones, as well as for refining predictive models for the flux of fine‐grained sediments across the Earth’s surface.
Background: Active esophageal cooling during pulmonary vein isolation (PVI) with radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF) is increasingly being utilized to reduce esophageal injury and atrioesophageal fistula formation. Randomized controlled data also show trends towards increased freedom from AF when using active cooling. This study aimed to compare one-year arrhythmia recurrence rates between patients treated with luminal esophageal temperature (LET) monitoring versus active esophageal cooling during left atrial ablation. Methods: Data from two healthcare systems (including 3 hospitals and 4 electrophysiologists) were reviewed for patient rhythm status at one-year follow up after receiving PVI for the treatment of AF. Results were compared between patients receiving active esophageal cooling and those treated with traditional LET monitoring using Kaplan-Meier estimates. Results: A total of 513 patients were reviewed; 253 received LET monitoring using either single or multi-sensor temperature probes, and 260 received active cooling. Mean age was 66.8 (SD +/-10) years, and 36.8% were female. Arrhythmias were 60.1% paroxysmal AF, 34.3% persistent AF, and 5.6% long-standing persistent AF, with no significant difference between groups. At one-year follow-up, KM estimates for freedom from AF were 58.2% for LET monitored patients and 72.2% for actively cooled patients, for absolute increase in freedom from AF of 14% with active esophageal cooling (P=.03). Conclusions: In this first study to date of the association between esophageal protection strategy and long-term efficacy of left atrial RF ablation, a clinically and statistically significant improvement in freedom from atrial arrhythmia at one-year was found in patients treated with active esophageal cooling when compared to patients that received LET monitoring.
In this paper we describe how we created an undergraduate course in psychoanalysis for Colorado College students at the Chicago Psychoanalytic Institute, how the course is constructed in terms of meeting with psychoanalysts, how we create an optimal ambiance for the course, how it is part of a psychoanalysis minor, and why it has been so meaningful for the students. We also articulate why we think teaching psychoanalysis to undergraduates is extraordinarily important and the difficulties and risks in doing so.
We use an experiment to examine whether form of payment (cash or mobile money) affects estimates of intertemporal choice and risk taking. We find that form of payment does not affect temporal discounting and risk taking. Given that participants prefer payment via mobile money, the results suggest that there are minimal concerns with using mobile money to pay participants in experimental studies.
Protein amyloid fibrils have widespread implications for human health. Over the last twenty years, fibrillation has been studied using a variety of crowding agents to mimic the packed interior of cells or to probe the mechanisms and pathways of the process. We tabulate and review these results by considering three classes of crowding agent: synthetic polymers, osmolytes and other small molecules, and globular proteins. While some patterns are observable for certain crowding agents, the results are highly variable and often depend on the specific pairing of crowder and fibrillating protein.
Humor can facilitate relationship-building and comfort in new experiences, essential elements for nature education programs prioritizing inclusive practices. This article presents insights on using humor in outdoor educational settings from a qualitative case study of an equity-driven nature education program. I present four key elements of instructors’ uses of humor. The program instructors used humor to (1) foster students’ emotional safety and comfort with novelty or physical risk; (2) subvert students’ expectations of “normal” behavior (for students and adults alike) and of possible program experiences; and (3) bond among themselves and mitigate tensions between their and visiting teachers’ practices. Additionally, (4) the instructors consciously discussed and set positionally-aware norms for their most common uses of and responses to humor. Through these four elements, I suggest that the program instructors used humor to create provisional safe spaces for themselves and their students—spaces that normalize engaging with novelty, discomfort, and continuous learning. To close, I offer suggestions for nature educators wishing to facilitate cross-cultural inclusivity through humor in their programs.
Sublethal exposure to methylmercury (MeHg) can have consequences for the reproductive, neurological, and physiological health of birds. Songbirds, regardless of trophic position, are often exposed to mercury (Hg) and may be at risk for health effects – especially if they inhabit a place that is subject to high Hg atmospheric deposition and/or have local conditions that are prone to methylation. This study investigates Hg concentrations in terrestrial songbirds of Southeast Michigan, where historical and present-day anthropogenic emissions of heavy metals are elevated. We collected tail feather samples from 223 songbirds across four different species during summer and fall of 2018 and 2019. The mean (±SE) Hg concentration across all samples was 103 ± 3.43 ng/g of dry feather weight. Mercury concentration varied significantly among species, and by age and site in some species, but not by sex. Mean concentrations were nearly seven times higher in two omnivore species, American robin (Turdus migratorius) and European starling (Sturnus vulgaris), than in the two granivore species, American goldfinch (Spinus tristus) and house sparrow (Passer domesticus). Juveniles had higher feather Hg concentrations than adults in all species except American goldfinches - which feed their young primarily seeds, further supporting a role of diet in exposure. We also found a negative correlation between Hg concentration and body condition in American robins, but further research is needed to verify this relationship. While our sample concentrations do not exceed the threshold for sublethal effects, our findings provide insight into the patterns of Hg concentrations in terrestrial songbirds, which may help in understanding Hg exposure pathways, bioaccumulation and risks in terrestrial species.
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1,201 members
Mark Wilson
  • Dept. of Organismal Biology and Ecology
Lynne E Gratz
  • Environmental Studies Program
Bob Jacobs
  • Psychology
Rachel S Jabaily
  • Organismal Biology and Ecology
Jim Parco
  • Department of Economics and Business
14 East Cache La Poudre, 80903, Colorado Springs, CO, United States
Head of institution
President Jill Tiefenthaler