2,238 research outputs found

    An EPIIC Vision to Evolve Project Integration, Innovation, and Collaboration with Broad Impact for How NASA Executes Complex Projects

    Get PDF
    Evolving Project Integration, Innovation, and Collaboration (EPIIC) is a vision defined to transform the way projects manage information to support real-time decisions, capture best practices and lessons learned, perform assessments, and manage risk across a portfolio of projects. The foundational project management needs for data and information will be revolutionized through innovations on how we manage and access that data, implement configuration control, and certify compliance. The embedded intelligence of new interactive data interfaces integrate technical and programmatic data such that near real time analytics can be accomplished to more efficiently and accurately complete systems engineering and project management tasks. The system-wide data analytics that are integrated into customized data interfaces allows the growing team of engineers and managers required to develop and implement major NASA missions the ability to access authoritative source(s) of system information while greatly reducing the labor required to complete system assessments. This would allow, for example, much of what is accomplished in a scheduled design review to take place as needed, between any team members, at any time. An intelligent data interface that rigorously integrates systems engineering and project management information in near real time can provide substantially greater insight for systems engineers, project managers, and the large diverse teams required to complete a complex project. System engineers, programmatic personnel (those who focus on cost, schedule, and risk), the technical engineering disciplines, and project management can realize immediate benefit from the shared vision described herein. Implementation of the vision also enables significant improvements in the performance of the engineered system being developed

    A randomized controlled trial of assisted intention monitoring for the rehabilitation of executive impairments following acquired brain injury

    Get PDF
    Background. Acquired brain injury (ABI) can impair executive function, impeding planning and attainment of intentions. Research shows promise for some goal-management rehabilitation interventions. However, evidence that alerts assist monitoring and completion of day-to-day intentions is limited. Objective. To examine the efficacy of brief goal-directed rehabilitation paired with periodic SMS text messages designed to enhance executive monitoring of intentions (assisted intention monitoring [AIM]). Methods. A randomized, double-blind, controlled trial was conducted. Following a baseline phase, 74 people with ABI and executive problems were randomized to receive AIM or control (information and games) for 3 weeks (phase 1) before crossing over to either AIM or no intervention (phase 2). The primary outcome was change in composite score of proportion of daily intentions achieved. A total of 59 people (71% male; 46% traumatic brain injury) completed all study phases. Results. Per protocol crossover analysis found a significant benefit of AIM for all intentions [F(1, 56) = 4.28; P = .04; f = 0.28; 3.7% mean difference; 95% CI = 0.1%-7.4%] and all intentions excluding a proxy prospective memory task [F(1, 55) = 4.79; P = .033; f = 0.28, medium effect size; 3% mean difference; 95% CI = 0.3%-5.6%] in the absence of significant changes on tests of executive functioning. Intention-to-treat analyses, comparing AIM against control at the end of phase 1 revealed no statistically significant differences in the attainment of intentions. Conclusion. Combining brief executive rehabilitation with alerts may be effective for some in improving achievement of daily intentions, but further evaluation of clinical effectiveness and mechanisms is required

    Carotid Atheroinflammation Is Associated With Cerebral Small Vessel Disease Severity.

    Get PDF
    Background: Atherosclerosis is a systemic inflammatory disease, with common inflammatory processes implicated in both atheroma vulnerability and blood-brain barrier disruption. This prospective multimodal imaging study aimed to measure directly the association between systemic atheroma inflammation ("atheroinflammation") and downstream chronic cerebral small vessel disease severity. Methods: Twenty-six individuals with ischemic stroke with ipsilateral carotid artery stenosis of >50% underwent 18fluoride-fluorodeoxyglucose-positron emission tomography within 2 weeks of stroke. Small vessel disease severity and white matter hyperintensity volume were assessed using 3-tesla magnetic resonance imaging also within 2 weeks of stroke. Results: Fluorodeoxyglucose uptake was independently associated with more severe small vessel disease (odds ratio 6.18, 95% confidence interval 2.1-18.2, P < 0.01 for the non-culprit carotid artery) and larger white matter hyperintensity volumes (coefficient = 14.33 mL, P < 0.01 for the non-culprit carotid artery). Conclusion: These proof-of-concept results have important implications for our understanding of the neurovascular interface and potential therapeutic exploitation in the management of systemic atherosclerosis, particularly non-stenotic disease previously considered asymptomatic, in order to reduce the burden of chronic cerebrovascular disease

    Risk factors for eating disorder symptoms at 12 years of age: A 6-year longitudinal cohort study

    Get PDF
    Eating disorders pose risks to health and wellbeing in young adolescents, but prospective studies of risk factors are scarce and this has impeded prevention efforts. This longitudinal study aimed to examine risk factors for eating disorder symptoms in a population-based birth cohort of young adolescents at 12 years. Participants from the Gateshead Millennium Study birth cohort (n = 516; 262 girls and 254 boys) completed self-report questionnaire measures of eating disorder symptoms and putative risk factors at age 7 years, 9 years and 12 years, including dietary restraint, depressive symptoms and body dissatisfaction. Body mass index (BMI) was also measured at each age. Within-time correlates of eating disorder symptoms at 12 years of age were greater body dissatisfaction for both sexes and, for girls only, higher depressive symptoms. For both sexes, higher eating disorder symptoms at 9 years old significantly predicted higher eating disorder symptoms at 12 years old. Dietary restraint at 7 years old predicted boys' eating disorder symptoms at age 12, but not girls'. Factors that did not predict eating disorder symptoms at 12 years of age were BMI (any age), girls’ dietary restraint at 7 years and body dissatisfaction at 7 and 9 years of age for both sexes. In this population-based study, different patterns of predictors and correlates of eating disorder symptoms were found for girls and boys. Body dissatisfaction, a purported risk factor for eating disorder symptoms in young adolescents, developed concurrently with eating disorder symptoms rather than preceding them. However, restraint at age 7 and eating disorder symptoms at age 9 years did predict 12-year eating disorder symptoms. Overall, our findings suggest that efforts to prevent disordered eating might beneficially focus on preadolescent populations

    Age-Related Decline in Reproductive Sensitivity to Inhibition by Short Photoperiod in Peromyscus Leucopus

    Get PDF
    Seasonal environments favor the timing, of reproduction to match seasons when Successful reproduction is most likely. Most species of temperate zone mammals suppress reproduction in winter using changes in day length as a cue. In many species, individuals vary genetically in how strongly they respond to these seasonal cues. Individuals also may modify their response to day length depending upon other factors, including their age. Age-specific changes might occur because young, peripubertal rodents are more strongly affected by harsh conditions than adults, and therefore might be more sensitive to inhibitory photoperiods. We tested the hypothesis that genetic variation in responses to photoperiod persists as individuals age. Young males from a captive population of white-footed mice (Peromyscus leucopus) that is genetically variable for reproductive inhibition by short day length (SD) were tested for photoperiod responses. Mice were placed in SD within 3 days after birth, tested at age 70 days, allowed to mature for at least 18 weeks at long day length, and then tested again as adults aged \u3e= 34 weeks. Young males were more likely to be strongly reproductively Suppressed by SD than adults, indicating that age-specific changes in reproductive strategy occur in this Population. However, males that were reproductively photoresponsive when young also were more likely to be reproductively photoresponsive as adults. Thus, genetic tendency for reproductive sensitivity to photoperiod is a trait retained from puberty to adulthood, but attenuates with age

    Electrical lithosphere beneath the Kaapvaal craton, southern Africa

    Get PDF
    Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): B04105, doi:10.1029/2010JB007883.A regional-scale magnetotelluric (MT) experiment across the southern African Kaapvaal craton and surrounding terranes, called the Southern African Magnetotelluric Experiment (SAMTEX), has revealed complex structure in the lithospheric mantle. Large variations in maximum resistivity at depths to 200–250 km relate directly to age and tectonic provenance of surface structures. Within the central portions of the Kaapvaal craton are regions of resistive lithosphere about 230 km thick, in agreement with estimates from xenolith thermobarometry and seismic surface wave tomography, but thinner than inferred from seismic body wave tomography. The MT data are unable to discriminate between a completely dry or slightly “damp” (a few hundred parts per million of water) structure within the transitional region at the base of the lithosphere. However, the structure of the uppermost ∼150 km of lithosphere is consistent with enhanced, but still low, conductivities reported for hydrous olivine and orthopyroxene at levels of water reported for Kaapvaal xenoliths. The electrical lithosphere around the Kimberley and Premier diamond mines is thinner than the maximum craton thickness found between Kimberley and Johannesburg/Pretoria. The mantle beneath the Bushveld Complex is highly conducting at depths around 60 km. Possible explanations for these high conductivities include graphite or sulphide and/or iron metals associated with the Bushveld magmatic event. We suggest that one of these conductive phases (most likely melt-related sulphides) could electrically connect iron-rich garnets in a garnet-rich eclogitic composition associated with a relict subduction slab.In addition to the funding and logistical support provided by SAMTEX consortium members, this work is also supported by research grants from the National Science Foundation (EAR‐0309584 and EAR‐0455242 through the Continental Dynamics Program), the Department of Science and Technology, South Africa, and Science Foundation of Ireland (grant 05/RFP/ GEO001)

    A non-canonical ESCRT pathway, including histidine domain phosphotyrosine phosphatase (HD-PTP), is used for down-regulation of virally ubiquitinated MHC class I.

    Get PDF
    The Kaposi's sarcoma-associated herpes virus (KSHV) K3 viral gene product effectively down-regulates cell surface MHC class I. K3 is an E3 ubiquitin ligase that promotes Lys(63)-linked polyubiquitination of MHC class I, providing the signal for clathrin-mediated endocytosis. Endocytosis is followed by sorting into the intralumenal vesicles (ILVs) of multivesicular bodies (MVBs) and eventual delivery to lysosomes. The sorting of MHC class I into MVBs requires many individual proteins of the four endosomal sorting complexes required for transport (ESCRTs). In HeLa cells expressing the KSHV K3 ubiquitin ligase, the effect of RNAi-mediated depletion of individual proteins of the ESCRT-0 and ESCRT-I complexes and three ESCRT-III proteins showed that these are required to down-regulate MHC class I. However, depletion of proteins of the ESCRT-II complex or of the ESCRT-III protein, VPS20 (vacuolar protein sorting 20)/CHMP6 (charged MVB protein 6), failed to prevent the loss of MHC class I from the cell surface. Depletion of histidine domain phosphotyrosine phosphatase (HD-PTP) resulted in an increase in the cell surface concentration of MHC class I in HeLa cells expressing the KSHV K3 ubiquitin ligase. Rescue experiments with wild-type (WT) and mutant HD-PTP supported the conclusion that HD-PTP acts as an alternative to ESCRT-II and VPS20/CHMP6 as a link between the ESCRT-I and those ESCRT-III protein(s) necessary for ILV formation. Thus, the down-regulation of cell surface MHC class I, polyubiquitinated by the KSHV K3 ubiquitin ligase, does not employ the canonical ESCRT pathway, but instead utilizes an alternative pathway in which HD-PTP replaces ESCRT-II and VPS20/CHMP6.This work was supported by an MRC research grant to J.P.L. (G0900113). M.D.J.P. and J.L.E. were MRC research students and S.P. a Wellcome Trust research student. K.B. was a British Heart Foundation Intermediate Fellow and P.J.L. is a Wellcome Trust Principal Fellow. The CIMR is supported by a Wellcome Trust Strategic Award 100140 and an electron microscope was purchased with Wellcome Trust grant 093026.This is the final version of the article. It first appeared from Portland Press via http://dx.doi.org/10.1042/BJ2015033

    On the Heterogeneity of Metal-Line and Ly-Alpha Absorption in Galaxy "Halos" at z~0.7

    Get PDF
    We examine the properties of two galaxy "halos" at z ~ 0.7 in the TON 153 (z_em = 1.01) quasar field. The first absorber-galaxy pair (G1) is a z = 0.672, L_B = 4.3 L*_B, E/S0 galaxy probed at D = 58 kpc. G1 is associated with a remarkable five-component Ly-alpha complex having tau_LL < 0.4, W_r(Lya) = 2.8 A, and a velocity spread of v = 1420 km/s. We find no MgII, CIV, NV, nor OVI absorption in these clouds and infer metallicity upper limits of -3 < log(Z/Z_sun) < -1, depending upon assumptions of photoionized or collisionally ionized gas. The second absorber-galaxy pair (G2) is a z = 0.661, L_B = 1.8 L*_B, Sab galaxy probed at D = 103 kpc. G2 is associated with metal--enriched (log Z/Z_sun ~ -0.4) photoionized gas having N(HI) ~ 18.3 and a velocity spread of v = 200 km/s. The very different G1 and G2 systems both have gas-galaxy properties inconsistent with the standard luminosity dependent galaxy "halo" model commonly invoked for quasar absorption line surveys. We emphasize that mounting evidence is revealing that extended galactic gaseous envelopes in the regime of D < 100 kpc do not exhibit a level of homogeneity supporting a standardized halo model. Selection effects may have played a central role in the development of a simple model. We discuss the G1 and G2 systems in the context of Lambda-CDM models of galaxy formation and suggest that the heterogeneous properties of absorber-galaxy pairs is likely related to the range of overdensities from which galaxies and gas structures arise.Comment: 5 pages, 2 figures, Accepted to Ap

    Teaching about complex systems is no simple matter: building effective professional development for computer-supported complex systems instruction

    Get PDF
    The recent next generation science standards in the United States have emphasized learning about complex systems as a core feature of science learning. Over the past 15 years, a number of educational tools and theories have been investigated to help students learn about complex systems; but surprisingly, little research has been devoted to identifying the supports that teachers need to teach about complex systems in the classroom. In this paper, we aim to address this gap in the literature. We describe a 2-year professional development study in which we gathered data on teachers’ abilities and perceptions regarding the delivery of computer-supported complex systems curricula. We present results across the 2 years of the project and demonstrate the need for particular instructional supports to improve implementation efforts, including providing differentiated opportunities to build expertise and addressing teacher beliefs about whether computational-model construction belongs in the science classroom. Results from students’ classroom experiences and learning over the 2 years are offered to further illustrate the impact of these instructional supports.National Science Foundation (U.S.). Discovery Research K– 12 (Grant 1019228

    Changes in performance and bio-mathematical model performance predictions during 45 days of sleep restriction in a simulated space mission

    Get PDF
    Lunar habitation and exploration of space beyond low-Earth orbit will require small crews to live in isolation and confinement while maintaining a high level of performance with limited support from mission control. Astronauts only achieve approximately 6 h of sleep per night, but few studies have linked sleep deficiency in space to performance impairment. We studied crewmembers over 45 days during a simulated space mission that included 5 h of sleep opportunity on weekdays and 8 h of sleep on weekends to characterize changes in performance on the psychomotor vigilance task (PVT) and subjective fatigue ratings. We further evaluated how well bio-mathematical models designed to predict performance changes due to sleep loss compared to objective performance. We studied 20 individuals during five missions and found that objective performance, but not subjective fatigue, declined from the beginning to the end of the mission. We found that bio-mathematical models were able to predict average changes across the mission but were less sensitive at predicting individual-level performance. Our findings suggest that sleep should be prioritized in lunar crews to minimize the potential for performance errors. Bio-mathematical models may be useful for aiding crews in schedule design but not for individual-level fitness-for-duty decisions
    corecore