1,716 research outputs found

    Pmp27 Promotes Peroxisomal Proliferation

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    Peroxisomes perform many essential functions in eukaryotic cells. The weight of evidence indicates that these organelles divide by budding from preexisting peroxisomes. This process is not understood at the molecular level. Peroxisomal proliferation can be induced in Saccharomyces cerevisiae by oleate. This growth substrate is metabolized by peroxisomal enzymes. We have identified a protein, Pmp27, that promotes peroxisomal proliferation. This protein, previously termed Pmp24, was purified from peroxisomal membranes, and the corresponding gene, PMP27, was isolated and sequenced. Prop27 shares sequence similarity with the Pmp30 family in Candida boidinii. Pmp27 is a hydrophobic peroxisomal membrane protein but it can be extracted by high pH, suggesting that it does not fully span the bilayer. Its expression is regulated by oleate. The function of Pmp27 was probed by observing the phenotype of strains in which the protein was eliminated by gene disruption or overproduced by expression from a multicopy plasmid. The strain containing the disruption (3B) was able to grow on all carbon sources tested, including oleate, although growth on oleate, glycerol, and acetate was slower than wild type. Strain 3B contained peroxisomes with all of the enzymes of β-oxidation. However, in addition to the presence of a few modestly sized peroxisomes seen in a typical thin section of a cell growing on oleate-containing medium, cells of strain 3B also contained one or two very large peroxisomes. In contrast, cells in a strain in which Pmp27 was overexpressed contained an increased number of normal-sized peroxisomes. We suggest that Pmp27 promotes peroxisomal proliferation by participating in peroxisomal elongation or fission.

    Integrating and Visualizing Tropical Cyclone Data Using the Real Time Mission Monitor

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    The Real Time Mission Monitor (RTMM) is a visualization and information system that fuses multiple Earth science data sources, to enable real time decision-making for airborne and ground validation experiments. Developed at the NASA Marshall Space Flight Center, RTMM is a situational awareness, decision-support system that integrates satellite imagery, radar, surface and airborne instrument data sets, model output parameters, lightning location observations, aircraft navigation data, soundings, and other applicable Earth science data sets. The integration and delivery of this information is made possible using data acquisition systems, network communication links, network server resources, and visualizations through the Google Earth virtual globe application. RTMM is extremely valuable for optimizing individual Earth science airborne field experiments. Flight planners, scientists, and managers appreciate the contributions that RTMM makes to their flight projects. A broad spectrum of interdisciplinary scientists used RTMM during field campaigns including the hurricane-focused 2006 NASA African Monsoon Multidisciplinary Analyses (NAMMA), 2007 NOAA-NASA Aerosonde Hurricane Noel flight, 2007 Tropical Composition, Cloud, and Climate Coupling (TC4), plus a soil moisture (SMAP-VEX) and two arctic research experiments (ARCTAS) in 2008. Improving and evolving RTMM is a continuous process. RTMM recently integrated the Waypoint Planning Tool, a Java-based application that enables aircraft mission scientists to easily develop a pre-mission flight plan through an interactive point-and-click interface. Individual flight legs are automatically calculated "on the fly". The resultant flight plan is then immediately posted to the Google Earth-based RTMM for interested scientists to view the planned flight track and subsequently compare it to the actual real time flight progress. We are planning additional capabilities to RTMM including collaborations with the Jet Propulsion Laboratory in the joint development of a Tropical Cyclone Integrated Data Exchange and Analysis System (TC IDEAS) which will serve as a web portal for access to tropical cyclone data, visualizations and model output

    Maternal psychological distress in primary care and association with child behavioural outcomes at age three

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    Observational studies indicate children whose mothers have poor mental health are at increased risk of socio-emotional behavioural difficulties, but it is unknown whether these outcomes vary by the mothers’ mental health recognition and treatment status. To examine this question, we analysed linked longitudinal primary care and research data from 1078 women enrolled in the Born in Bradford cohort. A latent class analysis of treatment status and self-reported distress broadly categorised women as (a) not having a common mental disorder (CMD) that persisted through pregnancy and the first 2 years after delivery (N = 756, 70.1 %), (b) treated for CMD (N = 67, 6.2 %), or (c) untreated (N = 255, 23.7 %). Compared to children of mothers without CMD, 3-year-old children with mothers classified as having untreated CMD had higher standardised factor scores on the Strengths and Difficulties Questionnaire (d = 0.32), as did children with mothers classified as having treated CMD (d = 0.27). Results were only slightly attenuated in adjusted analyses. Children of mothers with CMD may be at risk for socio-emotional and behavioural difficulties. The development of effective treatments for CMD needs to be balanced by greater attempts to identify and treat women. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00787-015-0777-2) contains supplementary material, which is available to authorized users

    Report from the Passive Microwave Data Set Management Workshop

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    Passive microwave data sets are some of the most important data sets in the Earth Observing System Data and Information System (EOSDIS), providing data as far back as the early 1970s. The widespread use of passive microwave (PM) radiometer data has led to their collection and distribution over the years at several different Earth science data centers. The user community is often confused by this proliferation and the uneven spread of information about the data sets. In response to this situation, a Passive Microwave Data Set Management Workshop was held 17 ]19 May 2011 at the Global Hydrology Resource Center, sponsored by the NASA Earth Science Data and Information System (ESDIS) Project. The workshop attendees reviewed all primary (Level 1 ]3) PM data sets from NASA and non ]NASA sensors held by NASA Distributed Active Archive Centers (DAACs), as well as high ]value data sets from other NASA ]funded organizations. This report provides the key findings and recommendations from the workshop as well as detailed tabluations of the datasets considered

    High Energy Neutrinos from Cosmological Gamma-Ray Burst Fireballs

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    Observations suggest that γ\gamma-ray bursts (GRBs) are produced by the dissipation of the kinetic energy of a relativistic fireball. We show that a large fraction, ≥10\ge 10%, of the fireball energy is expected to be converted by photo-meson production to a burst of ∼1014eV\sim10^{14} eV neutrinos. A km^2 neutrino detector would observe at least several tens of events per year correlated with GRBs, and test for neutrino properties (e.g. flavor oscillations, for which upward moving τ\tau's would be a unique signature, and coupling to gravity) with an accuracy many orders of magnitude better than is currently possible.Comment: Submitted to PRL (4 pages, LaTeX

    A Good Samaritan inspired foundation for a fair health care system

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    Distributive justice on the income and on the service aspects is the most vexing modern day problem for the creation and maintenance of an all inclusive health care system. A pervasive problem of all current schemes is the lack of effective cost control, which continues to result in increasing burdens for all public and private stakeholders. This proposal posits that the responsibility and financial obligation to achieve an ideal outcome of equal and affordable access and benefits for all citizens is misplaced. The Good Samaritan demonstrated basic ethical principles, which are revisited, elaborated and integrated into a new approach to health care. The participants are limited to individual contributors and beneficiaries and organized as a citizen carried, closed, independent, and self-sufficient self-governing cooperative for their own and the benefit of a minority of disadvantaged health care consumers. The government assumes oversight, provides arbitration, enforces democratic decision making, a scheme of progressive taxation, a separate and transparent accounting system, and a balance between income and reinvestment in health care. The results are a fair distribution of cost, its effective control, and increased individual motivation to take on responsibility for personal health as a private good and a sharpened focus towards community health. At the sociopolitical level the government as well as employers are released from the inappropriate burden of catering to individual health

    Coherent Matter Wave Transport in Speckle Potentials

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    This article studies multiple scattering of matter waves by a disordered optical potential in two and in three dimensions. We calculate fundamental transport quantities such as the scattering mean free path â„“s\ell_s, the Boltzmann transport mean free path \elltrb, and the Boltzmann diffusion constant DBD_B, using a diagrammatic Green functions approach. Coherent multiple scattering induces interference corrections known as weak localization which entail a reduced diffusion constant. We derive the corresponding expressions for matter wave transport in an correlated speckle potential and provide the relevant parameter values for a possible experimental study of this coherent transport regime, including the critical crossover to the regime of strong or Anderson localization.Comment: 33 pages, minor corrections, published versio

    The positions of primary and secondary schools in the English school field: a case of durable inequality

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    In interviews as part of a research study of structural reform in England, some tension between primary head teachers and their secondary peers was evident. This was symptomatic of a long-standing difference in status between the two phases. At a time when relations between stakeholders in local systems are subject to change, we seek to understand anew why that might be the case and how the tension we found was evidence of a current difference of power within interactions between representatives of the phases. We analyse differences of size, resources, workforce, pedagogy and history, and how they have resulted in different, and differently valued, practices and professional identities. We explore how attributes of the two phases have been counterposed and how, in complex interaction with wider discourses of politics, gender and age, this process has invested the differences with meanings and values that tend to relegate attributes associated with primary school. By focusing on the activation of cumulative inequality in interactions, we contribute a complementary perspective to studies of perceived relative status and highlight the implications for understanding school positioning in local arenas as the role of local authorities is reduced

    Bayesian Methods for Exoplanet Science

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    Exoplanet research is carried out at the limits of the capabilities of current telescopes and instruments. The studied signals are weak, and often embedded in complex systematics from instrumental, telluric, and astrophysical sources. Combining repeated observations of periodic events, simultaneous observations with multiple telescopes, different observation techniques, and existing information from theory and prior research can help to disentangle the systematics from the planetary signals, and offers synergistic advantages over analysing observations separately. Bayesian inference provides a self-consistent statistical framework that addresses both the necessity for complex systematics models, and the need to combine prior information and heterogeneous observations. This chapter offers a brief introduction to Bayesian inference in the context of exoplanet research, with focus on time series analysis, and finishes with an overview of a set of freely available programming libraries.Comment: Invited revie
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