University of Vermont
  • Burlington, VT, United States
Recent publications
This retrospective study used data from patients treated for uterine fibroids with ultrasound-guided high-intensity focused ultrasound (USgHIFU) from April 2015 to April 2019. One hundred and seven patients with solitary fibroids were divided into two groups: (1) the L group with larger fibroids (≥10 cm) and (2) the S group with smaller fibroids (<10 cm). Using magnetic resonance imaging (MRI), we examined the efficacy of high-intensity focused ultrasound (HIFU) ablation by comparing uterine and fibroid volumes before and three months after the procedure. The three-month follow-up clinical visit used a visual analog scale and a uterine fibroid symptom health-related quality of life questionnaire to evaluate clinical symptoms. Both the L and S groups had significant reduction in uterine and fibroid volumes, but the rate was significantly higher in the S group (p < 0.05). Both groups also had improvements in clinical symptoms, but there was no statistical difference. USgHIFU reduced the size of both large and small fibroids but was most effective on fibroids smaller than 10 cm. Both the L and S groups had improved dysmenorrhea symptoms and quality of life.
The imposed lockdown, due to the COVID-19 outbreak, resulted in the rise to a “new normal” of working from home. This study explores how the lockdown and the sudden shift in the working style affected the job satisfaction of employees in India. We examined the relationship of job satisfaction with work autonomy, and determined whether work-family conflict, and anxiety due to COVID-19 are negatively related to job satisfaction amongst employees working from home in India. Through a correlational research design, a total of 211 participants took part in the study, and only 200 of the data, representing a 95% response rate, were eligible for further analysis. The data were analyzed using Structural Equation Modeling, and the results showed that work-family conflict and anxiety related to COVID-19 have a negative correlation with job satisfaction, while work autonomy had a positive correlation with job satisfaction. Perceived work autonomy, work-family conflict, and anxiety related to the COVID-19 pandemic significantly predicted job satisfaction and accounted for an overall 37.8% of the variance in job satisfaction. The findings of the current study provide valuable insight into the consequences of a pandemic or similar uncontrollable event and augmented the literature on organizational behavior where most employees are compelled to work remotely, either full-time or part-time. The theoretical and empirical implications of how work-family conflict and anxiety related to the COVID-19 pandemic negatively impact the job satisfaction of employees in India were discussed. Evaluation of the structural relationship (SEM) reveals that the overall exogenous constructs significantly predicted job satisfaction of employees working from home in India during the COVID-19 pandemic.
Citizen-generated counter speech is a promising way to fight hate speech and promote peaceful, non-polarized discourse. However, there is a lack of large-scale longitudinal studies of its effectiveness for reducing hate speech. To this end, we perform an exploratory analysis of the effectiveness of counter speech using several different macro- and micro-level measures to analyze 180,000 political conversations that took place on German Twitter over four years. We report on the dynamic interactions of hate and counter speech over time and provide insights into whether, as in ‘classic’ bullying situations, organized efforts are more effective than independent individuals in steering online discourse. Taken together, our results build a multifaceted picture of the dynamics of hate and counter speech online. While we make no causal claims due to the complexity of discourse dynamics, our findings suggest that organized hate speech is associated with changes in public discourse and that counter speech—especially when organized—may help curb hateful rhetoric in online discourse.
GitHub has become the central online platform for much of open source, hosting most open source code repositories. With this popularity, the public digital traces of GitHub are now a valuable means to study teamwork and collaboration. In many ways, however, GitHub is a convenience sample, and may not be representative of open source development off the platform. Here we develop a novel, extensive sample of public open source project repositories outside of centralized platforms. We characterized these projects along a number of dimensions, and compare to a time-matched sample of corresponding GitHub projects. Our sample projects tend to have more collaborators, are maintained for longer periods, and tend to be more focused on academic and scientific problems.
While joining farmer cooperatives has been identified as a way for farmers, especially small farmers, to overcome their limitations in the marketplace and increase their income, this paper presents an analytical framework for examining how farmer cooperative may increase farmer income in rural China, empirically assesses the impacts of such membership on household income, and examines how the membership may affect income inequality. Data from a large-scale survey of rural households in China are used to examine the impacts of farmer cooperative membership and other factors on household income through a multivariate regression analysis and to test whether the impacts are different across income groups through a quantile regression analysis. The propensity score matching technique is used to address potential self-selection bias problems in the dataset and quantile regression is used to examine the impact for different income quantiles or groups of farmers. The empirical results indicate that farmers participating in professional cooperatives, on average, earned significantly higher income than their counterparts, but the positive impact was not statistically significant for low-income quantiles. This finding suggests that encouraging the development of and participation in farmer cooperatives could increase the average income but may not contribute directly to the policy goal of reducing income inequality in rural China.
Ibrutinib is effective in the treatment of relapsed/refractory (R/R) marginal zone lymphoma (MZL) with an overall response rate (ORR) of 48%. However, factors associated with response (or lack thereof) to ibrutinib in R/R MZL in clinical practice are largely unknown. To answer this question, we performed a multicenter (25 US centers) cohort study and divided the study population into three groups: “ibrutinib responders”—patients who achieved complete or partial response (CR/PR) to ibrutinib; “stable disease (SD)”; and “primary progressors (PP)”—patients with progression of disease as their best response to ibrutinib. One hundred and nineteen patients met the eligibility criteria with 58%/17% ORR/CR, 29% with SD, and 13% with PP. The median PFS and OS were 29 and 71.4 months, respectively, with no difference in PFS or OS based on the ibrutinib line of therapy or type of therapy before ibrutinib. Patients with complex cytogenetics had an inferior PFS (HR = 3.08, 95% CI 1.23–7.67, p = 0.02), while those with both complex cytogenetics (HR = 3.00, 95% CI 1.03–8.68, p = 0.04) and PP (HR = 13.94, 95% CI 5.17–37.62, p < 0.001) had inferior OS. Only primary refractory disease to first-line therapy predicted a higher probability of PP to ibrutinib (RR = 3.77, 95% CI 1.15–12.33, p = 0.03). In this largest study to date evaluating outcomes of R/R MZL treated with ibrutinib, we show that patients with primary refractory disease and those with PP on ibrutinib are very high-risk subsets and need to be prioritized for experimental therapies.
Integrating ecosystem services (ESs), i.e., the benefits humans obtain from nature, into decision making is essential for the sustainable management of resilient urban landscapes, where people and nature are interdependent. However, ES spatial assessments often leave unanswered important questions about their relationship to social systems and their implications in management. In this study, we identified ES provisioning areas in the Chicago metropolitan region that have potential to produce ESs across multiple ES-categories (i.e., ES hotspots). We also identified areas lacking this capacity (i.e., ES coldspots). We then analyzed spatial linkages to local demographics. Specifically, we: (1) modelled the distribution of ES hotspots and ES coldspots at 30-m resolution; (2) compared the proportion of total ES-hotspot and ES-coldspot land area to that of racial groups and residents living below the poverty line; and (3) determined overlap of ES hotspots and ES coldspots with conservation, managed and public open land. We found that, at regional level, ES-hotspots correlate negatively with racial minorities. We also observed that a great number of ES hotspots overlap with conserved and government-managed land, but because these land types inversely correlate with racial minorities it is likely that these cannot serve to alleviate race-based ES inequality if targeted. Therefore, we made a number of suggestions on how to circumvent this issue, including acquiring land (for conservation) in areas where racial minorities live the most, particularly targeting vacant lots and grassland within the City of Chicago to address ES inequity in the region.
Understanding why people do what they do is central to advancing equitable and sustainable futures. Yet, theories about human action are fragmented across many social science disciplines, each with its own jargon and implicit assumptions. This fragmentation has hindered theory integration and accessibility of theories relevant to a given challenge. We synthesized human action theories from across the humanities and social sciences. We developed eight underlying assumptions—metatheories—that reveal a fundamental organization of human action theories. We describe each metatheory and the challenges that it best elucidates (illustrated with climate change examples). No single metatheory addresses the full range of factors and problems; only one treats interactions between factors. Our synthesis will help researchers, policymakers, and practitioners gain a multifaceted understanding of human action. Expected final online publication date for the Annual Review of Environment and Resources, Volume 47 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Cerebral blood flow (CBF) is exquisitely controlled to meet the ever-changing demands of active neurons in the brain. Brain capillaries are equipped with sensors of neurovascular coupling agents released from neurons/astrocytes onto the outer wall of a capillary. While capillaries can translate external signals into electrical and Ca2+ changes, control mechanisms from the lumen are less clear. The continuous flux of red blood cells and plasma through narrow-diameter capillaries imposes mechanical forces on the luminal (inner) capillary wall. Whether—and, if so, how—the ever-changing CBF could be mechanically sensed in capillaries is not known. Here, we propose and provide evidence that the mechanosensitive Piezo1 channels operate as mechanosensors in CNS capillaries to ultimately regulate CBF. Patch clamp electrophysiology confirmed the expression and function of Piezo1 channels in brain cortical and retinal capillary endothelial cells. Mechanical or pharmacological activation of Piezo1 channels evoked currents that were sensitive to Piezo1 channel blockers. Using genetically encoded Ca2+ indicator (Cdh5-GCaMP8) mice, we observed that Piezo1 channel activation triggered Ca2+ signals in endothelial cells. An ex vivo pressurized retina preparation was employed to further explore the mechanosensitivity of capillary Piezo1-mediated Ca2+ signals. Genetic and pharmacologic manipulation of Piezo1 in endothelial cells had significant impacts on CBF, reemphasizing the crucial role of mechanosensation in blood flow control. In conclusion, this study shows that Piezo1 channels act as mechanosensors in capillaries, and that these channels initiate crucial Ca2+ signals. We further show that Piezo1 modulates CBF, an observation of profound significance for the control of brain blood flow in health and in disorders where hemodynamic forces are disrupted, such as hypertension.
Climate change affects the Arctic and sub-Arctic regions by exposing previously frozen permafrost to thaw, unlocking soil nutrients, changing hydrological processes, and boosting plant growth. As a result, sub-Arctic tundra is subject to a shrub expansion, called “shrubification”, at the expense of sedge species. Depending on the intrinsic foliar properties of these plant species, changes in foliar mineral element fluxes with shrubification in the context of permafrost degradation may influence topsoil mineral element composition. Despite the potential implications of changes in topsoil mineral element concentrations for the fate of organic carbon, this remains poorly quantified. Here, we investigate vegetation foliar and topsoil mineral element composition (Si, K, Ca, P, Mn, Zn, Cu, Mo, V) across a natural gradient of permafrost degradation at a typical sub-Arctic tundra at Eight Mile Lake (Alaska, USA). Results show that foliar mineral element concentrations are higher (up to 9 times; Si, K, Mo for all species, and for some species Zn) or lower (up to 2 times; Ca, P, Mn, Cu, V for all species, and for some species Zn) in sedge than in shrub species. As a result, a vegetation shift over ∼40 years has resulted in lower topsoil concentrations in Si, K, Zn, and Mo (respectively of 52, 24, 20, and 51%) in highly degraded permafrost sites compared to poorly degraded permafrost sites due to lower foliar fluxes of these elements. For other elements (Ca, P, Mn, Cu, and V), the vegetation shift has not induced a marked change in topsoil concentrations at this current stage of permafrost degradation. A modeled amplified shrubification associated with a further permafrost degradation is expected to increase foliar Ca, P, Mn, Cu, and V fluxes, which will likely change these element concentrations in topsoil. These data can serve as a first estimate to assess the influence of other shifts in vegetation in Arctic and sub-Arctic tundra such as sedge expansion under wetter soil conditions.
The impacts of recreational boating on lake ecosystems are often not well characterized, including for Lake Champlain (US/Canada) where excess watershed phosphorus loading drives cyanobacteria blooms. Improperly disposed boater-generated sewage has not been considered as a source of phosphorus in total maximum daily load models or implementation plans for the Lake. Surveys of marinas and boaters informed sewage production estimates by marina-using boaters. Annual boater-generated sewage volume was estimated to range between 2,445 and 5,184 m³. These volumes allowed estimation of potential phosphorus contributions to Lake Champlain by improperly disposed sewage at varied rates of discharge. Such contributions were negligible compared to known Lake Champlain phosphorus sources, suggesting use of Clean Water Funds to reduce phosphorus inputs may not be warranted. Nonetheless, due to potential for pathogen contamination, continued financial support through other means was recommended to allow marinas to operate and maintain pumpout facilities at rates reasonable to boaters. Management implications Improperly disposed sewage was estimated to represent <0.01% of annual phosphorus contributions to Lake Champlain (USA/Canada). As such, Clean Water Funds targeted to address significant phosphorus inputs to the lake may not be warranted. Nonetheless, continued governmental support for marinas to provide and maintain sewage pumpout facilities for free or at rates most boaters were willing to pay is recommended to minimize introduction of pathogens associated with fecal pollution. To further help ensure compliance with sewage disposal regulations, educational materials and messaging to boaters to encourage use of pumpout facilities should be made available in English and French due to significant populations of boaters speaking each language.
In the struggle to mitigate anthropogenic threats to environmental systems, science has made great progress identifying and quantifying the potential of various mitigation initiatives. It has made less progress in identifying and assessing how those initiatives will affect their targets and whether those initiatives can be adopted given the constraints of social, economic, and political systems. We present a framework for a science of mitigation that integrates understanding of mitigation potential with empirically based and context-specific knowledge from the social and behavioral sciences to address those gaps. The goal is to help change agents move beyond subjective judgment or broad theory toward a stronger basis for choosing and implementing mitigation strategies. This developing science incorporates knowledge about mitigation potential with knowledge about the plasticity of human responses to initiatives for change, feasibility of adopting and implementing such initiatives, and emerging principles for the effective design of initiatives. We place current and emerging lines of research within this framework and show how they can be developed to better inform practical mitigation choices, identify key research needs for this integrative science, and propose ways to support the needed efforts.
Purpose Research on the learning benefits of the feedback-rich formative assessment environment of virtual patient cases (VPCs) has largely been limited to single institutions and focused on discrete clinical skills or topical knowledge. To augment current understanding, we designed a multi-institutional study to explore the distinct and cumulative effects of VPC formative assessments and optional self-assessment questions (SAQs) on exam performance. Method In this correlational study, we examined the records of 1,692 students on their family medicine (FM) clerkship at 20 medical schools during the 2014–2015 academic year. Schools utilized an established online curriculum, which included family medicine VPCs, embedded formative assessments, context-rich SAQs corresponding with each VPC, and an associated comprehensive family medicine exam. We used mixed-effects modeling to relate the student VPC composite formative assessment score, SAQ completion, and SAQ performance to students’ scores on the FM final examination. Results Students scored higher on the final exam when they performed better on the VPC formative assessments, completed associated SAQs, and scored higher on those SAQs. Students’ SAQ completion enhanced examination performance above that explained by engagement with the VPC formative assessments alone. Conclusions This large-scale, multi-institutional study furthers the body of research on the effect of formative assessments associated with VPCs on exam performance and demonstrates the added benefit of optional associated SAQs. Findings highlight opportunities for future work on the broader impact of formative assessments for learning, exploring the benefits of integrating VPCs and SAQs, and documenting effects on clinical performance and summative exam scores.
High-throughput microRNA sequencing was performed during differentiation of MC3T3-E1 osteoblasts to develop working hypotheses for specific microRNAs that control osteogenesis. The expression data show that miR-101a, which targets the mRNAs for the epigenetic enzyme Ezh2 and many other proteins, is highly upregulated during osteoblast differentiation and robustly expressed in mouse calvaria. Transient elevation of miR-101a suppresses Ezh2 levels, reduces tri-methylation of lysine 27 in histone 3 (H3K27me3; a heterochromatic mark catalyzed by Ezh2), and accelerates mineralization of MC3T3-E1 osteoblasts. We also examined skeletal phenotypes of an inducible miR-101a transgene under direct control of doxycycline administration. Experimental controls and mir-101a over-expressing mice were exposed to doxycycline in utero and postnatally (up to 8 weeks of age) to maximize penetrance of skeletal phenotypes. Male mice that over-express miR-101a have increased total body weight and longer femora. MicroCT analysis indicate that these mice have increased trabecular bone volume fraction, trabecular number and trabecular thickness with reduced trabecular spacing as compared to controls. Histomorphometric analysis demonstrates a significant reduction in osteoid volume to bone volume and osteoid surface to bone surface. Remarkably, while female mice also exhibit a significant increase in bone length, no significant changes were noted by microCT (trabecular bone parameters) and histomorphometry (osteoid parameters). Hence, miR-101a upregulation during osteoblast maturation and the concomitant reduction in Ezh2 mediated H3K27me3 levels may contribute to the enhanced trabecular bone parameters in male mice. However, the sex-specific effect of miR-101a indicates that more intricate epigenetic mechanisms mediate physiological control of bone formation and homeostasis.
Organophosphines have garnered attention from many avenues ranging from agriculture to fine chemicals. One-time use of phosphate resources has made sustainable use of phosphorus overall imperative. Hydrophosphination serves as an efficient method to selectively prepare P–C bonds, furnishing a range of phosphorus-containing molecules while maximizing the efficient use of phosphorus. Since its discovery in the 1990s, a wide array of catalysts have appeared for hydrophosphination, a reaction that is spontaneous in some instances. This review presents a representative view of the literature based on known catalysts through mid-2022, highlighting extensions to unique substrates and advances in selectivity. While several excellent reviews have appeared for aspects of this transformation, this review is meant as a comprehensive guide to reported catalysts.
Conduct problems (CP) in patients with disruptive behavior disorders have been linked to impaired prefrontal processing of negative facial affect compared to controls. However, it is unknown whether associations with prefrontal activity during affective face processing hold along the CP dimension in a healthy population sample, and how subcortical processing is affected. We measured functional brain responses during negative affective face processing in 1444 healthy adolescents [ M = 14.39 years (SD = 0.40), 51.5% female] from the European IMAGEN multicenter study. To determine the effects of CP, we applied a two-step approach: (a) testing matched subgroups of low versus high CP, extending into the clinical range [ N = 182 per group, M = 14.44 years, (SD = 0.41), 47.3% female] using analysis of variance, and (b) considering (non)linear effects along the CP dimension in the full sample and in the high CP group using multiple regression. We observed no significant cortical or subcortical effect of CP group on brain responses to negative facial affect. In the full sample, regression analyses revealed a significant linear increase of left orbitofrontal cortex (OFC) activity with increasing CP up to the clinical range. In the high CP group, a significant inverted u-shaped effect indicated that left OFC responses decreased again in individuals with high CP. Left OFC activity during negative affective processing which is increasing with CP and decreasing in the highest CP range may reflect on the importance of frontal control mechanisms that counteract the consequences of severe CP by facilitating higher social engagement and better evaluation of social content in adolescents.
Purpose The purpose of this study was to test the feasibility, usability, and acceptability of implementing a web-based method for collecting social network and longitudinal daily interaction data from cancer survivors and their caregivers. Methods Young adult and sexual/gender minority cancer survivors and their informal caregivers were recruited as dyads. Feasibility data, including enrollment and retention, were captured. Individual social network data were collected at baseline and used to individualize daily electronically delivered surveys assessing characteristics of daily social support-related interactions with identified network members for 14 days. Follow-up questionnaires assessing usability and exit interviews assessing acceptability were completed at the end of the 2-week study period. Results Fourteen survivor-caregiver dyads (28 individual participants) were enrolled and completed all baseline and final measures. Participants completed 85.2% of daily diary reports and reported excellent usability ratings. Acceptability was also high. In qualitative interviews, participants reported enjoying the daily reflection on social support facilitated by our methods. Conclusions Our method has been shown to be highly feasible, usable, and acceptable. Implications for Cancer Survivors Developing better data collection tools can lead to better understanding of the social support cancer survivors and their caregivers receive, and how the social network structure facilitates or creates barriers to accessing this support.
Metacognitive deficits affect Alzheimer’s disease (AD) patient safety and increase caregiver burden. The brain areas that support metacognition are not well understood. 112 participants from the Imaging and Genetic Biomarkers for AD (ImaGene) study underwent comprehensive cognitive testing and brain magnetic resonance imaging. A performance-prediction paradigm was used to evaluate metacognitive abilities for California Verbal Learning Test–II learning (CVLT-II 1–5) and delayed recall (CVLT-II DR); Visual Reproduction-I immediate recall (VR-I Copy) and Visual Reproduction-II delayed recall (VR-II DR); Rey-Osterrieth Complex Figure Copy (Rey-O Copy) and delayed recall (Rey-O DR). Vertex-wise multivariable regression of cortical thickness was performed using metacognitive scores as predictors while controlling for age, sex, education, and intracranial volume. Subjects who overestimated CVLT-II DR in prediction showed cortical atrophy, most pronounced in the bilateral temporal and left greater than right (L > R) frontal cortices. Overestimation of CVLT-II 1–5 prediction and DR performance in postdiction showed L > R associations with medial, inferior and lateral temporal and left posterior cingulate cortical atrophy. Overconfident prediction of VR-I Copy performance was associated with right greater than left medial, inferior and lateral temporal, lateral parietal, anterior and posterior cingulate and lateral frontal cortical atrophy. Underestimation of Rey-O Copy performance in prediction was associated with atrophy localizing to the temporal and cingulate areas, and in postdiction, with diffuse cortical atrophy. Impaired metacognition was associated to cortical atrophy. Our results indicate that poor insight into one’s cognitive abilities is a pervasive neurodegenerative feature associated with AD across the cognitive spectrum.
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5,289 members
Osama F Harraz
  • Department of Pharmacology
Timothy Stickle
  • Department of Psychological Science
Diane M Jaworski
  • Department of Neurological Sciences
Erika Miles Edwards
  • Department of Mathematics and Statistics
Peter Dodds
  • Department of Mathematics and Statistics
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