Browsing by Subject "development"
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Item Open Access A comparative analysis of egg provisioning using mass spectrometry during rapid life history evolution in sea urchins.(Evolution & development, 2019-05-17) Davidson, Phillip L; Thompson, J Will; Foster, Matthew W; Moseley, M Arthur; Byrne, Maria; Wray, Gregory AA dramatic life history switch that has evolved numerous times in marine invertebrates is the transition from planktotrophic (feeding) to lecithotrophic (nonfeeding) larval development-an evolutionary tradeoff with many important developmental and ecological consequences. To attain a more comprehensive understanding of the molecular basis for this switch, we performed untargeted lipidomic and proteomic liquid chromatography-tandem mass spectrometry on eggs and larvae from three sea urchin species: the lecithotroph Heliocidaris erythrogramma, the closely related planktotroph Heliocidaris tuberculata, and the distantly related planktotroph Lytechinus variegatus. We identify numerous molecular-level changes possibly associated with the evolution of lecithotrophy in H. erythrogramma. We find the massive lipid stores of H. erythrogramma eggs are largely composed of low-density, diacylglycerol ether lipids that, contrary to expectations, appear to support postmetamorphic development and survivorship. Rapid premetamorphic development in this species may instead be powered by upregulated carbohydrate metabolism or triacylglycerol metabolism. We also find proteins involved in oxidative stress regulation are upregulated in H. erythrogramma eggs, and apoB-like lipid transfer proteins may be important for echinoid oogenic nutrient provisioning. These results demonstrate how mass spectrometry can enrich our understanding of life history evolution and organismal diversity by identifying specific molecules associated with distinct life history strategies and prompt new hypotheses about how and why these adaptations evolve.Item Open Access A Smartphone App With a Digital Care Pathway for Patients Undergoing Spine Surgery: Development and Feasibility Study.(JMIR perioperative medicine, 2020-10-16) Ponder, Madison; Ansah-Yeboah, Abena A; Charalambous, Lefko T; Adil, Syed M; Venkatraman, Vishal; Abd-El-Barr, Muhammad; Haglund, Michael; Grossi, Peter; Yarbrough, Chester; Dharmapurikar, Rajeev; Gellad, Ziad; Lad, Shivanand PBackground
There is a great unmet clinical need to provide patients undergoing spinal surgery and their caregivers with ongoing, high-quality care before and after surgery in an efficiency-focused health care environment.Objective
The objective of this study is to design, develop, and evaluate the acceptability and feasibility of a novel planning-, outcomes-, and analytics-based smartphone app called ManageMySurgery (MMS) in patients undergoing elective spine surgery (MMS-Spine).Methods
The development process of the MMS app was conducted over 2 sequential stages: (1) an evidence-based intervention design with refinement from surgeon and patient feedback and (2) feasibility testing in a clinical pilot study. We developed a novel, mobile-based, Health Insurance Portability and Accountability Act-compliant platform for interventional and surgical procedures. It is a patient-centric mobile health app that streamlines patients' interactions with their care team. MMS divides the patient journey into phases, making it feasible to provide customized care pathways that meet patients' unique needs. Patient-reported outcomes are easily collected and conform to the National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) standard.Results
We tested the feasibility of the MMS-Spine app with patients undergoing elective spine surgery at a large academic health system. A total of 47 patients undergoing elective spine surgery (26 cervical spine and 21 lumbar spine surgeries) downloaded and used MMS-Spine to navigate their surgical journey, quantify their baseline characteristics and postoperative outcomes, and provide feedback on the utility of the app in preparing for and recovering from their spinal surgery. The median age was 59.0 (range 33-77) years, 22 of the 47 patients (47%) were women, and 26 patients (55%) had commercial insurance. Of the 47 patients, a total of 33 (70%) logged in on an iOS device, 11 (23%) on an Android device, and 3 (6%) on a computer or tablet. A total of 17 of the 47 patients (36%) added a caregiver, of which 7 (41%) logged in. The median number of sign-ins was 2. A total of 38 of 47 patients (81%) completed their baseline preoperative PROMIS-29 outcomes, and 14 patients (30%) completed at least one PROMIS-29 survey during the postoperative period. Of the 24 patients who completed the MMS survey, 21 (88%) said it was helpful during preparation for their procedure, 16 (67%) said it was helpful during the postoperative period, and 23 (96%) said that they would recommend MMS to a friend or family member.Conclusions
We used a patient-centered approach based on proven behavior change techniques to develop a comprehensive smartphone app for patients undergoing elective spine surgery. The optimized version of the app is ready for formal testing in a larger randomized clinical study to establish its cost-effectiveness and effect on patients' self-management skills and long-term outcomes.Item Embargo Aiding or Failing the Bureaucracy? Foreign Aid in Uganda's Central Government(2024) Nagawa, MariaHow does foreign aid shape bureaucratic incentives and impact bureaucrats' performance? Despite the large amounts of development assistance directed towards the public sectors of developing countries across the world, this question has gone largely unanswered in the literature. This is a critical gap since bureaucrats are key to the implementation of development programs and undergird state capacity. In this dissertation, I argue that aid alters bureaucrats' incentives and drives them to make tradeoffs between their regular government duties and aid projects. As a result, performance on aid projects is boosted at the expense of government programming and organizational coherence.
I test my argument using a combination of qualitative, survey experimental, and observational panel data. My qualitative data consists of interviews of 39 bureaucrats across various ministries and agencies in Uganda's central government. My survey experimental data comprises responses from 559 mid-level bureaucrats across 6 ministries and approximately 70 departments, also in Uganda's central government. As one of the top recipients of aid in Africa, Uganda provides an ideal context for understanding how development aid impacts recipient governments. For my panel, I draw on data that runs across 161 countries over a period of 17 years.
Evidence from the panel data suggests that increased dependency on project aid lowers a country's bureaucratic quality. The qualitative and experimental findings demonstrate the mechanisms that drive these findings. The qualitative results show that aid projects disrupt bureaucratic hierarchies, distort bureaucrats' incentives, and undermine government programming. These findings are supported by the experimental results, which show that bureaucrats are willing to allocate effort away from their regular government duties and towards aid projects as financial incentives on aid projects increase. Taken together, the results highlight that in endeavouring to ensure the success of relatively short term aid programs, donors compromise bureaucratic capacity.
This comprehensive analysis, building upon rich descriptive insights to link individual-level to state-level effects, provides a critical lens into the mechanisms underlying how aid works and the possible implications for both aid effectiveness and state capacity. The findings challenge donors' reliance on project aid as a disbursement modality and underscore a need to reevaluate the role of aid in the bureaucracies of developing countries.
Item Open Access Economic Structure and Performance(1986) Kuran, TimurThis festschrift, featuring 26 papers by 36 authors, is a fitting tribute to Hollis Chenery who, for over three decades, has been one of the luminaries of development economics. Most of the issues he brought into focus, the methodologies he helped develop, and the styl- ized facts he hammered into the consciousness of the profession receive detailed attention. The contributors include numerous influential scholars, many of whom are his distinguished students and colleagues from Harvard, Stan- ford, and the World Bank. Although a few of the papers lack originality, sophistication, or polish, the overall quality of the volume is high...Item Embargo Functional development of brain-scale neural circuits underlying vertebrate visuomotor transformations(2024) Loring, Matthew DavidVisual behaviors are ubiquitous throughout the animal kingdom, assisting organisms in navigation, reproduction, and survival. The neuronal circuits underlying visual processing change substantially throughout development and adapt throughout life while maintaining proper function. However, the neurobiological mechanisms underlying visual functional circuit maturation remain unknown and largely underexamined. Addressing these questions requires a tractable model system that offers access to all participating neurons and quantifiable visuomotor behaviors across development. This work leverages the genetically and optically tractable zebrafish to monitor the functional maturation of the optomotor response (OMR), an innate visuomotor orienting behavior. This visually guided behavior and the associated neural circuits have been characterized in larval zebrafish older than 6 days post-fertilization. Monitoring OMR behaviors from the moment visual information is provided to the brain at 72 hours post fertilization (hpf), I reveal a stage-like development, uncovering the specific developmental transitions from the immature, non-responsive to a robust OMR repertoire at 120 hpf. To investigate the associated neural circuit maturation, I used two-photon calcium imaging to monitor the activity of nearly all neurons of the OMR circuitry, including the retinorecipient pretectum, revealing distinct region-specific developmental trajectories. Neuronal visual response properties correlate with the developmental stage, explaining behavioral maturation. While sensory neural processing is present in young, 72 hpf zebrafish, lack of hindbrain activation suggests that sensory and motor circuits are not yet connected. Finally, by combining longitudinal imaging with computational cell-tracking methods, I reveal that individual neurons display stable tuning characteristics from 72 hpf onwards, suggesting neurons emerge in specialized circuit roles. These results provide a quantitative framework for advancing our understanding of functional interactions driving visuomotor circuit maturation in vertebrates at the cellular level.
Item Open Access Migration and development in Ethiopia: Exploring the mechanisms behind an emerging mobility transition(Migration Studies, 2021-12-01) Schewel, K; Asmamaw, LBThis article examines the impact of Ethiopia's historical development on the nature, volume, and direction of internal and international migration. We describe three important trends associated with an emerging 'mobility transition': the sedentarization of nomadic and semi-nomadic populations; the urbanization of internal migration trajectories; and the diversification of international migration. Within these overarching trends, we discuss periods of political conflict, resettlement, and famine that led to significant internal and international displacement. We then explore the drivers of these mobility shifts, evaluating the relative influence of various political, economic, cultural, and technological developments on migration patterns over time. Our analyses distinguish between the deep drivers of an emerging mobility transition (e.g. nation-state formation, rising educational attainment, infrastructure development, and industrialization) and the drivers of displacement (e.g. political conflict or resettlement programs) that can suddenly affect the movements of large population segments. This detailed case study contributes to a growing body of research on the 'mobility transition' by revealing how a society's entire mobility complex changes - not only levels of international migration - as the social transformations associated with modern-day development proceed.Item Open Access Pioneers in Development: Second Series(1988) Kuran, TimurMost doubtful, though, is Gruchy's unbridled faith in planning. The unpredictable dynamics Gruchy finds in economic systems argue strongly against centralized planning, as neo- Austrians suggest. At the practical level most relevant to institutionalism, economic regula- tion has too frequently led to either chaos, rent seeking, or "capture" by the regulated.Item Unknown Refraining from use diminishes cannabis-associated epigenetic changes in human sperm.(Environmental epigenetics, 2021-01) Schrott, Rose; Murphy, Susan K; Modliszewski, Jennifer L; King, Dillon E; Hill, Bendu; Itchon-Ramos, Nilda; Raburn, Douglas; Price, Thomas; Levin, Edward D; Vandrey, Ryan; Corcoran, David L; Kollins, Scott H; Mitchell, John TCannabis use alters sperm DNA methylation, but the potential reversibility of these changes is unknown. Semen samples from cannabis users and non-user controls were collected at baseline and again following a 77-day period of cannabis abstinence (one spermatogenic cycle). Users and controls did not significantly differ by demographics or semen analyses. Whole-genome bisulfite sequencing identified 163 CpG sites with significantly different DNA methylation in sperm between groups (P < 2.94 × 10-9). Genes associated with altered CpG sites were enriched with those involved in development, including cardiogenesis and neurodevelopment. Many of the differences in sperm DNA methylation between groups were diminished after cannabis abstinence. These results indicate that sustained cannabis abstinence significantly reduces the number of sperm showing cannabis-associated alterations at genes important for early development.Item Unknown Rewiring of an Early Developmental Gene Regulatory Network in Lecithotrophic Sea Urchins(2024) Swart, Jane SingletonThe field of evolution and development explores how novelty arises from delicate and highly coordinated developmental processes. As even minor disruptions to development can have catastrophic effects on an organism, studying evolutionary change reveals which developmental processes are most crucially conserved. The sea urchin genus Heliocidaris provides a model in which to explore these questions. The genus contains two closely related species with dramatically different modes of development: the planktotrophic (feeding) species, H. tuberculata, and lecithotrophic (non-feeding) species, H. erythrogramma, diverge only roughly 5 million years, a remarkably short time for such dramatic changes to evolve. H. erythrogramma has an abbreviated larval stage in which major components of the embryo, including a functional gut and structural skeleton are missing. Planktotrophic development, as in H. tuberculata, is characterized by asymmetrical cleavage at the sixteen-cell stage, creating the micromeres which establish the signaling center of the embryo and specify the skeletogenic cell lineage. H. erythrogramma notably does not form micromeres, a major disruption to the understood model of sea urchin development. This document explores how lecithotrophic sea urchin H. erythrogramma establishes the signaling center and the skeletogenic lineage following the loss of the micromeres. In planktotrophic development, micromeres are the first cells to express components of the Wnt signaling pathway, which establishes the anterior-posterior axis of the embryo. Disruptions of wnt signaling in H. erythrogramma indicate that its role in gastrulation and specification of the endoderm are largely conserved across the switch to lecithotrophic development. However, expression patterns of wnt ligands reveal delays in the timing of these signaling events, and rewiring of wnt activity outside of primary axis specification. The micromeres are also the progenitors of the skeletogenic cell lineage. H. erythrogramma skeleton is both delayed and reduced as compared to planktotrophs, indicating disruptions to skeletal development. Using assays and perturbations of components of the skeletal pathway, I have demonstrated that the activation of skeletogenesis has been rewired in H. erythrogramma. However, the downstream pathway appears largely conserved. These results provide groundwork for constructing the developmental gene regulatory network in H. erythrogramma and better understanding how the planktotrophic dGRN evolved.
Item Unknown Who prefers to stay? voluntary immobility among youth in Ethiopia, India, and Vietnam(Journal of Ethnic and Migration Studies, 2022-01-01) Schewel, K; Fransen, SFar fewer people migrate than global disparities in wealth and well-being would lead us to predict, yet we know relatively little about why those who presumably have much to gain from migration prefer to stay in place. This article examines the motivations of young people who express the preference to stay put, and asks what individual and household characteristics are associated with voluntary immobility. Using survey data collected in Ethiopia, India, and Vietnam for the Young Lives Project, we find that the majority of young people surveyed envision a future within their home country, and between 32 per cent (Ethiopia) and 60 per cent (Vietnam) prefer to stay in their current location. Most youth prefer to stay for family-related reasons. Living in an urban area and engagement in farm work are associated with greater staying aspirations, but only for youth from the most resource-poor or the wealthiest households. Higher levels of schooling, wealth, feelings of self-efficacy and paid employment are consistently associated with diminished desires to stay, with stronger effects for youth from rural settings, resource-poor households, and women. Our results reveal the social patterning of staying aspirations and have important implications for development interventions that seek to enhance aspirations and capabilities of individuals to stay in place.