1,468 research outputs found

    Identification of dividing, determined sensory neuron precursors in the mammalian neural crest

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    Sensory and autonomic neurons of the vertebrate peripheral nervous system are derived from the neural crest. Here we use the expression of lineage-specific transcription factors as a means to identify neuronal subtypes that develop in rat neural crest cultures grown in a defined medium. Sensory neurons, identified by expression of the POU-domain transcription factor Brn-3.0, develop from dividing precursors that differentiate within 2 days following emigration from the neural tube. Most of these precursors generate sensory neurons even when challenged with BMP2, a factor that induces autonomic neurogenesis in many other cells in the explants. Moreover, BMP2 fails to prevent expression of the sensory-specific basic helix-loop-helix (bHLH) transcription factors neurogenin1, neurogenin2 and neuroD, although it induces expression of the autonomic-specific bHLH factor MASH1 and the paired homeodomain factor Phox2a in other cells. These data suggest that there are mitotically active precursors in the mammalian neural crest that can generate sensory neurons even in the presence of a strong autonomic-inducing cue. Further characterization of the neurons generated from such precursors indicates that, under these culture conditions, they exhibit a proprioceptive and/or mechanosensory, but not nociceptive, phenotype. Such precursors may therefore correspond to a lineally (Frank, E. and Sanes, J. (1991) Development 111, 895-908) and genetically (Ma, Q., Fode, C., Guillemot, F. and Anderson, D. J. (1999) Genes Dev. 13, in press) distinct subset of early-differentiating precursors of large-diameter sensory neurons identified in vivo

    Age, Period, and Cohort Effects on Death Penalty Attitudes in the United States, 1974–2014

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    In this article, we further the understanding of both changes in public opinion on capital punishment in the United States and changes in the factors associated with public opinion on the death penalty. Support for the death penalty may be motivated by events happening during specific time periods, and it can vary across birth cohorts as a result of cohort-specific socialization processes, demographic changes, and formative events that are specific to each generation. An explication of the sources of and variation in death penalty attitudes over time would benefit from the accounting for the age of the respondent, the year of the survey response, and the birth cohort of the respondent. We improve on previous research by using multiple approaches including hierarchical age–period–cohort models and data from the General Social Survey (N = 41,474) to examine changes in death penalty attitudes over time and across birth cohorts. The results showed curvilinear age effects, strong period effects, and weak cohort effects on death penalty support. The violent crime rate explained much of the variation in support for the death penalty across periods. The examination of subgroup differences suggests that support for the death penalty is becoming concentrated among Whites, Protestants, and Republicans

    Cognitive dysfunction following desflurane versus sevoflurane general anesthesia in elderly patients: a randomized controlled trial.

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    UnlabelledAs life expectancy increases, more patients ≥65 years undergo general anesthesia. Anesthetic agents may contribute to postoperative cognitive dysfunction, and incidence may differ with anesthetic agents or intraoperative anesthesia depth. Responses to anesthetic adjuvants vary among elderly patients. Processed electroencephalography guidance of anesthetic may better ensure equivalent cerebral suppression. This study investigates postoperative cognitive dysfunction differences in elderly patients given desflurane or sevoflurane using processed electroencephalography guidance.IRB approved, randomized trial enrolled consenting patients ≥65 years scheduled for elective surgery requiring general anesthesia ≥120 minute duration. After written informed consent, patients were randomly assigned to sevoflurane or desflurane. No perioperative benzodiazepines were administered. Cognitive impairment was measured by an investigator blinded to group assignment using mini-Mental Status Examination (MMSE) at baseline; 1, 6, and 24 hours after the end of anesthesia. Mean arterial pressure was maintained within 20% of baseline. Anesthetic dose was adjusted to maintain moderate general anesthesia per processed electroencephalograpy (Patient State Index 25 to 50). The primary outcome measure was intergroup difference in MMSE change 1 hour after anesthesia (median; 95% confidence interval).110 patients consented; 26 were not included for analysis (no general anesthesia; withdrew consent; baseline MMSE abnormality; inability to perform postoperative MMSE; data capture failure); 47 sevoflurane and 37 desflurane were analyzed. There were no significant differences in patient characteristics; intraoperative mean blood pressure (desflurane 86.4; 81.3 to 89.6 versus sevoflurane 82.5; 80.2 to 86.1 mmHg; p = 0.42) or Patient State Index (desflurane 41.9; 39.0 to 44.0 versus sevoflurane 41.0; 37.5 to 44.0; p = 0.60) despite a lower MAC fraction in desflurane (0.82; 0.77 to 0.86) versus sevoflurane (0.96; 0.91 to 1.03; p < 0.001). MMSE decreased 1 hour after anesthesia (p < 0.001). The decrease at one hour was larger in sevoflurane (-2.5; -3.3 to -1.8) than desflurane (-1.3; -2.2 to -0.5; p = 0.03). MMSE returned to baseline by 6 hours after anesthesia.ConclusionsFor elderly patients in whom depth of anesthesia is maintained in the moderate range, both desflurane and sevoflurane are associated with transient decreases in cognitive function as measured by MMSE after anesthesia, with clinically insignificant differences between them in this setting.Trial registryClinicalTrials.gov NCT01199913

    Language matters: a study of teachers' uses of language for understanding practice

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    This dissertation asks how thinking about language can help us think about, and perhaps think differently about, education. Based on interviews with practicing classroom teachers who are also alumnae of a Master's in Education degree program for Experienced Teachers, in this work teachers describe encounters with various languages of education, including administrative languages and languages of the academy. Based in Bronwyn Davies' (2000) assertion that theorizing language allows us to make visible and disrupt our positioning through language, thereby repositioning ourselves, this study interprets practices of education through theories of language to explore both the contradictions and the possibilities for change that are revealed when languages of education are theorized. Located at the nexus of phenomenology, philosophical anthropology, and literary criticism, this work applies a postmodern hermeneutics (Nash, 1997) to the study of languages of education. Texts of teacher interviews were put into conversation with other key texts that inform thinking in education. Arguing that contemporary politics of education block meaningful conversations among educators, this work also confronts reductions of language that reduce practice. This work advances Kristeva's (1984) notion of the semiotic for its potential to open up and expand discursive situations and positions in education

    Noxious weed monitoring at the U.S. Air Force Academy: year 4 results

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    Prepared for: U.S. Air Force Academy, Dept. of Natural Resources.August 15, 2009.Includes bibliographical references

    Examining Behaviors Using Respondents’ Cell Phones and a Burst Design: Drinking and Activities Across the First Year of College Among Transitioning Freshmen

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    Purpose The study of developmental and life-course changes of an individual necessitates longitudinal data. Traditional panel designs, however, that tend to collect data annually or less often may not reflect change experienced by individuals especially in periods of transition. The first year of college likely is one such period in which change takes place at a rapid pace. Methods We followed approximately 100 residential college students across their freshman year. In an attempt to capture the changes taking place in friendships, activities, and alcohol use, we used a traditional panel design in which we administered structured surveys at the beginning, middle, and end of the academic year. We extended this design by employing a “burst” design to capture data frequently and in real time. Respondents were sent a text message with a link to a short survey asking about their activities. They received our text across 3-day intervals, multiple times within each day, approximately every month of the school year. Results In this paper, we discuss our approach and demonstrate the utility of burst designs. We show how such data collection schemes can complement more traditional designs by comparing information collected with the two approaches to show what could have been lost had we relied only on surveys at three time points. Conclusions The developmental transitions of college students occurred at a faster rate than our panel design could capture. Our findings suggest that researchers interested in a wide variety of transitions should employ burst designs alongside other traditional data collection techniques

    Sleep and Delinquency: Does the Amount of Sleep Matter?

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    Sleep, a key indicator of health, has been linked to a variety of indicators of well-being such that people who get an adequate amount generally experience greater well-being. Further, a lack of sleep has been linked to a wide range of negative developmental outcomes, yet sleep has been largely overlooked among researchers interested in adolescent delinquency. The purpose of this study was to explore the relationship between hours of sleep and delinquent behavior among adolescents by using data from Wave 1 of the National Longitudinal Study of Adolescent Health (n = 14,382; 50.2% female, 63.5% white). A series of negative binomial regressions showed that youth who typically sleep seven or fewer hours per night reported significantly more property delinquency than youth who sleep the recommended 8–10 h. Further, youth who reported sleeping 5 or fewer hours per night reported significantly more violent delinquency than youth who reported sleeping the recommended number of hours per night. The findings suggest that sleep is an important, and overlooked, dimension of delinquent behavior and studies that focus on adolescent health should further investigate the effects of insufficient sleep. Finally, the authors recommend that sleep and other relevant health behaviors be considered in the context of more comprehensive approaches to delinquency prevention and intervention

    History of dating violence and the association with late adolescent health

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    BACKGROUND: The present investigation expands upon prior studies by examining the relationship between health in late adolescence and the experience of physical/sexual and non-physical dating violence victimization, including dating violence types that are relevant to today’s adolescents (e.g., harassment via email and text messaging). We examined the relationship between physical/sexual and non-physical dating violence victimization from age 13 to 19 and health in late adolescence/early adulthood. METHODS: The sample comprised 585 subjects (ages 18 to 21; mean age, 19.8, SD = 1.0) recruited from The Ohio State University who completed an online survey to assess: 1) current health (depression, disordered eating, binge drinking, smoking, and frequent sexual behavior); and 2) dating violence victimization from age 13 to 19 (retrospectively assessed using eight questions covering physical, sexual, and non-physical abuse, including technology-related abuse involving stalking/harassment via text messaging and email). Multivariable models compared health indicators in never-exposed subjects to those exposed to physical/sexual or non-physical dating violence only. The multivariable models were adjusted for age and other non-dating abuse victimization (bullying; punched, kicked, choked by a parent/guardian; touched in a sexual place, forced to touch someone sexually). RESULTS: In adjusted analyses, compared to non-exposed females, females with physical/sexual dating violence victimization were at increased risk of smoking (prevalence ratio = 3.95); depressive symptoms (down/hopeless, PR = 2.00; lost interest, PR = 1.79); eating disorders (using diet aids, PR = 1.98; fasting, PR = 4.71; vomiting to lose weight, PR = 4.33); and frequent sexual behavior (5+ intercourse and oral sex partners, PR = 2.49, PR = 2.02; having anal sex, PR = 2.82). Compared to non-exposed females, females with non-physical dating violence only were at increased risk of smoking (PR = 3.61), depressive symptoms (down/hopeless, PR = 1.41; lost interest, PR = 1.36), eating disorders (fasting, PR = 3.37; vomiting, PR = 2.66), having 5+ intercourse partners (PR = 2.20), and having anal sex (PR = 2.18). For males, no health differences were observed for those experiencing physical/sexual dating violence compared to those who did not. Compared to non-exposed males, males with non-physical dating violence only were at increased risk of smoking (PR = 3.91) and disordered eating (fasting, using diet aids, vomiting, PR = 2.93). CONCLUSIONS: For females, more pronounced adverse health was observed for those exposed to physical/sexual versus non-physical dating violence. For both females and males, non-physical dating violence victimization contributed to poor health

    Global analysis of proliferation and cell cycle gene expression in the regulation of hematopoietic stem and progenitor cell fates

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    Knowledge of the molecular networks controlling the proliferation and fate of hematopoietic stem cells (HSC) is essential to understand their function in maintaining blood cell production during normal hematopoiesis and upon clinical transplantation. Using highly purified stem and progenitor cell populations, we define the proliferation index and status of the cell cycle machinery at discrete stages of hematopoietic differentiation and during cytokine-mediated HSC mobilization. We identify distinct sets of cell cycle proteins that specifically associate with differentiation, self-renewal, and maintenance of quiescence in HSC and progenitor cells. Moreover, we describe a striking inequality of function among in vivo cycling and quiescent HSC by demonstrating that their long-term engraftment potential resides predominantly in the G0 fraction. These data provide a direct link between HSC proliferation and function and identify discrete molecular targets in regulating HSC cell fate decisions that could have implications for both the therapeutic use of HSC and the understanding of leukemic transformation
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