Science.gov

Sample records for advancing fundamental understanding

  1. Experimental Investigation and Fundamental Understanding of a Slowed UH-60A Rotor at High Advance Ratios

    NASA Technical Reports Server (NTRS)

    Datta, Anubhav; Yeo, Hyeonsoo; Norman, Thomas R.

    2011-01-01

    This paper describes and analyzes the measurements from a full-scale, slowed RPM, UH-60A rotor tested at the National Full-Scale Aerodynamics Complex 40- by 80- ft wind tunnel up to an advance ratio of 1.0. A comprehensive set of measurements, that includes performance, blade loads, hub loads and pressures/airloads makes this data set unique. The measurements reveal new and rich aeromechanical phenomena that are special to this exotic regime. These include reverse chord dynamic stall, retreating side impulse in pitch-link load, large inboard-outboard elastic twist differential, supersonic flow at low subsonic advancing tip Mach numbers, diminishing rotor forces yet dramatic build up of blade loads, and dramatic blade loads yet benign levels of vibratory hub loads. The objective of this research is the fundamental understanding of these unique aeromechanical phenomena. The intent is to provide useful knowledge for the design of high speed, high efficiency, slowed RPM rotors of the future and a challenging database for advanced analyses validation.

  2. ADVANCING THE FUNDAMENTAL UNDERSTANDING AND SCALE-UP OF TRISO FUEL COATERS VIA ADVANCED MEASUREMENT AND COMPUTATIONAL TECHNIQUES

    SciTech Connect

    Biswas, Pratim; Al-Dahhan, Muthanna

    2012-11-01

    Tri-isotropic (TRISO) fuel particle coating is critical for the future use of nuclear energy produced byadvanced gas reactors (AGRs). The fuel kernels are coated using chemical vapor deposition in a spouted fluidized bed. The challenges encountered in operating TRISO fuel coaters are due to the fact that in modern AGRs, such as High Temperature Gas Reactors (HTGRs), the acceptable level of defective/failed coated particles is essentially zero. This specification requires processes that produce coated spherical particles with even coatings having extremely low defect fractions. Unfortunately, the scale-up and design of the current processes and coaters have been based on empirical approaches and are operated as black boxes. Hence, a voluminous amount of experimental development and trial and error work has been conducted. It has been clearly demonstrated that the quality of the coating applied to the fuel kernels is impacted by the hydrodynamics, solids flow field, and flow regime characteristics of the spouted bed coaters, which themselves are influenced by design parameters and operating variables. Further complicating the outlook for future fuel-coating technology and nuclear energy production is the fact that a variety of new concepts will involve fuel kernels of different sizes and with compositions of different densities. Therefore, without a fundamental understanding the underlying phenomena of the spouted bed TRISO coater, a significant amount of effort is required for production of each type of particle with a significant risk of not meeting the specifications. This difficulty will significantly and negatively impact the applications of AGRs for power generation and cause further challenges to them as an alternative source of commercial energy production. Accordingly, the proposed work seeks to overcome such hurdles and advance the scale-up, design, and performance of TRISO fuel particle spouted bed coaters. The overall objectives of the proposed work are

  3. Design and fundamental understanding of Minimum Quantity Lubrication (MQL) assisted grinding using advanced nanolubricants

    NASA Astrophysics Data System (ADS)

    Kalita, Parash

    Abrasive grinding is widely used across manufacturing industry for finishing parts and components requiring smooth superficial textures and precise dimensional tolerances and accuracy. Unlike any other machining operations, the complex thermo-mechanical processes during grinding produce excessive friction-induced energy consumption, heat, and intense contact seizures. Lubrication and cooling from grinding fluids is crucial in minimizing the deleterious effects of friction and heat to maximize the output part quality and process efficiency. The conventional flood grinding approach of an uneconomical application of large quantities of chemically active fluids has been found ineffective to provide sufficient lubrication and produces waste streams and pollutants that are hazardous to human health and environment. Application of Minimum Quantity Lubrication (MQL) that cuts the volumetric fluid consumption by 3-4 orders of magnitude have been extensively researched in grinding as a high-productivity and environmentally-sustainable alternative to the conventional flood method. However, the lubrication performance and productivity of MQL technique with current fluids has been critically challenged by the extreme thermo-mechanical conditions of abrasive grinding. In this research, an MQL system based on advanced nanolubricants has been proposed to address the current thermo-mechanical challenges of MQL grinding and improve its productivity. The nanolubricants were composed of inorganic Molybdenum Disulphide nanoparticles (≈ 200 nm) intercalated with organic macromolecules of EP/AW property, dispersed in straight (base) oils---mineral-based paraffin and vegetable-based soybean oil. After feasibility investigations into the grindability of cast iron using MQL with nanolubricants, this research focused on the fundamental understanding of tribological behavior and lubricating mechanisms of nanolubricants as a method to improve the productivity of MQL-assisted surface grinding

  4. Advances in analytical spectrochemistry with ionized gases. I. Improved fundamental understanding through laser based techniques. II. Novel bioanalytical applications

    NASA Astrophysics Data System (ADS)

    Gamez, Gerardo

    Over the past several decades plasma spectrochemistry has become the workhorse for performing elemental analysis. Nevertheless, we are still far from fully understanding the fundamental mechanisms that affect and led to the production of the analytical signal. Thus, the first part of this study was focused on improving our knowledge of plasma fundamental processes. First, the effect of exposing an inductively coupled plasma to a mass spectrometer sampling interface was investigated. Our results show that the mass spectrometer sampler affects the plasma fundamental parameters in a way that changes with gas flow, forward r.f. power, and plasma torch-to-sampler distance. The findings help to better explain the plasma sampling process and have made clear that results from mass-spectrometry based plasma diagnostics are applicable to unperturbed plasmas only as a rough approximation. Second, and instrument was constructed to characterize the fundamental parameters of an analytical glow discharge by using Thomson and Rayleigh laser scattering. A continuous dc glow discharge source was studied and a set of corresponding numerical modeling experiments were performed. The resulting theory agrees qualitatively with the experimental findings; moreover, the theoretical and experimental techniques often provide complementary information. Finally, a temporally and spatially resolved map of the fundamental parameters of a dc glow discharge operated in pulsed mode was obtained. The results confirm previously proposed electron energy-transfer mechanisms at the beginning of the pulse. In contrast, the findings call into question other mechanisms involving plasma gas metastable formation proposed for the time period immediately after the end of the pulse. In the second part of the study an imaging radio frequency glow discharge instrument was developed to provide three-dimensional elemental analysis of solids. The newly developed instrument was then applied to the simultaneous

  5. Understand vacuum-system fundamentals

    SciTech Connect

    Martin, G.R. ); Lines, J.R. ); Golden, S.W. )

    1994-10-01

    Crude vacuum unit heavy vacuum gas-oil (HVGO) yield is significantly impacted by ejector-system performance, especially at conditions below 20 mmHg absolute pressure. A deepcut vacuum unit, to reliably meet the yields, calls for proper design of all the major pieces of equipment. Ejector-system performance at deepcut vacuum column pressures may be independently or concurrently affected by: atmospheric column overflash, stripper performance or cutpoint; vacuum column top temperature and heat balance; light vacuum gas-oil (LVGO) pumparound entrainment to the ejector system; cooling-water temperature; motive steam pressure; non-condensible loading, either air leakage or cracked light-end hydrocarbons; condensible hydrocarbons; intercondenser or aftercondenser fouling ejector internal erosion or product build-up; and system vent back pressure. The paper discusses gas-oil yields; ejector-system fundamentals; condensers; vacuum-system troubleshooting; process operations; and a case study of deepcut operations.

  6. Fundamental understanding of matter: an engineering viewpoint

    SciTech Connect

    Cullingford, H.S.; Cort, G.E.

    1980-01-01

    Fundamental understanding of matter is a continuous process that should produce physical data for use by engineers and scientists in their work. Lack of fundamental property data in any engineering endeavor cannot be mitigated by theoretical work that is not confirmed by physical experiments. An engineering viewpoint will be presented to justify the need for understanding of matter. Examples will be given in the energy engineering field to outline the importance of further understanding of material and fluid properties and behavior. Cases will be cited to show the effects of various data bases in energy, mass, and momentum transfer. The status of fundamental data sources will be discussed in terms of data centers, new areas of engineering, and the progress in measurement techniques. Conclusions and recommendations will be outlined to improve the current situation faced by engineers in carrying out their work. 4 figures.

  7. Photoacoustic tomography: fundamentals, advances and prospects

    PubMed Central

    Yao, Junjie; Wang, Lihong V.

    2011-01-01

    Optical microscopy has been contributing to the development of life science for more than three centuries. However, due to strong optical scattering in tissue, its in vivo imaging ability has been restricted to studies at superficial depths. Advances in photoacoustic tomography (PAT) now allow multiscale imaging at depths from sub-millimeter to several centimeters, with spatial resolutions from sub-micrometer to sub-millimeter. Because of this high scalability and its unique optical absorption contrast, PAT is capable of performing anatomical, functional, molecular and fluid-dynamic imaging at various system levels, and is playing an increasingly important role in fundamental biological research and clinical practice. This Review discusses recent technical progress in PAT and presents corresponding applications. It ends with a discussion of several prospects and their technical challenges. PMID:22025335

  8. Towards fundamental understanding of ultracold KRb

    NASA Astrophysics Data System (ADS)

    Kotochigova, Svetlana

    2009-05-01

    The recent formation of ultracold KRb molecules in their absolute rovibrational ground state [1] has created great promise for study of collective phenomena that rely on the long-range interactions between polar molecules. Here we discuss the theoretical analysis of various essential properties of the KRb molecules [2] that accompanied these experimental advances. This analysis is based on multi-channel bound-state calculations of both ground and excited electronic states. We have found that the theoretical hyperfine and Zeeman mixed X^1&+circ; and a^3&+circ; vibrational structure shows excellent agreement with the experimentally observed structure. In addition, multi-channel calculations of the rovibrational structure of the excited state potentials have allowed us to find the optimal transitions to the lowest v=0 vibrational levels. Finally, we examine the dynamic polarizability of vibrationally cold KRb molecules as a function of laser frequency. Based on this knowledge, laser frequencies can be selected to minimize decoherence from loss of molecules due to spontaneous or laser-induced transitions. [1] K.-K. Ni, S. Ospelkaus, M. H. G. de Miranda, A. Peer, B. Neyenhuis, J. J. Zirbel, S. Kotochigova, P. S. Julienne, D. S. Jin, and J. Ye, Science 322, 231 (2008). [2] S. Kotochigova, E. Tiesinga, and P. S. Julienne, submitted to New J. Phys. (2009).

  9. Nanostructured materials for rechargeable batteries: synthesis, fundamental understanding and limitations

    SciTech Connect

    Zhan, Hui; Xiao, Jie; Nie, Zimin; Li, Xiaolin; Wang, Chong M.; Zhang, Jiguang; Liu, Jun

    2013-05-30

    Nanostructured materials have emerged as very attrcative electrode materials for energy storage due to their small sizes and structure/morphology related properties. The purpose of this article to discuss the opportunities and challenges of nanostructured materials for advanced energy storage devices. Nanostructured silicon (Si) anodes together with other cathode and anode materials are used as examples to illustrate the different methods available for synthesis and the range of materials that can be produced to improve the storage capacity and stability. Recent progresses in using well-defined nanostructures to gain new fundamental understanding of the complex electrochemical reactions and charge-discharge processes are also discussed. Finally, the paper addresses some key problems that are yet to be solved and the need to optimize the microstructures and control the high level architectures beyond nanoscale.

  10. Fundamental Limitations in Advanced LC Schemes

    SciTech Connect

    Mikhailichenko, A. A.

    2010-11-04

    Fundamental limitations in acceleration gradient, emittance, alignment and polarization in acceleration schemes are considered in application for novel schemes of acceleration, including laser-plasma and structure-based schemes. Problems for each method are underlined whenever it is possible. Main attention is paid to the scheme with a tilted laser bunch.

  11. Towards a fundamental understanding of natural gas hydrates.

    PubMed

    Koh, Carolyn A

    2002-05-01

    Gas clathrate hydrates were first identified in 1810 by Sir Humphrey Davy. However, it is believed that other scientists, including Priestley, may have observed their existence before this date. They are solid crystalline inclusion compounds consisting of polyhedral water cavities which enclathrate small gas molecules. Natural gas hydrates are important industrially because the occurrence of these solids in subsea gas pipelines presents high economic loss and ecological risks, as well as potential safety hazards to exploration and transmission personnel. On the other hand, they also have technological importance in separation processes, fuel transportation and storage. They are also a potential fuel resource because natural deposits of predominantly methane hydrate are found in permafrost and continental margins. To progress with understanding and tackling some of the technological challenges relating to natural gas hydrate formation, inhibition and decomposition one needs to develop a fundamental understanding of the molecular mechanisms involved in these processes. This fundamental understanding is also important to the broader field of inclusion chemistry. The present article focuses on the application of a range of physico-chemical techniques and approaches for gaining a fundamental understanding of natural gas hydrate formation, decomposition and inhibition. This article is complementary to other reviews in this field, which have focused more on the applied, engineering and technological aspects of clathrate hydrates. PMID:12122641

  12. Recent advances in understanding schizophrenia

    PubMed Central

    Haller, Chiara S.; Padmanabhan, Jaya L.; Lizano, Paulo; Torous, John

    2014-01-01

    Schizophrenia is a highly disabling disorder whose causes remain to be better understood, and treatments have to be improved. However, several recent advances have been made in diagnosis, etiopathology, and treatment. Whereas reliability of diagnosis has improved with operational criteria, including Diagnostic and Statistical Manual of Mental Disorders, (DSM) Fifth Edition, validity of the disease boundaries remains unclear because of substantive overlaps with other psychotic disorders. Recent emphasis on dimensional approaches and translational bio-behavioral research domain criteria may eventually help move toward a neuroscience-based definition of schizophrenia. The etiology of schizophrenia is now thought to be multifactorial, with multiple small-effect and fewer large-effect susceptibility genes interacting with several environmental factors. These factors may lead to developmentally mediated alterations in neuroplasticity, manifesting in a cascade of neurotransmitter and circuit dysfunctions and impaired connectivity with an onset around early adolescence. Such etiopathological understanding has motivated a renewed search for novel pharmacological as well as psychotherapeutic targets. Addressing the core features of the illness, such as cognitive deficits and negative symptoms, and developing hypothesis-driven early interventions and preventive strategies are high-priority goals for the field. Schizophrenia is a severe, chronic mental disorder and is among the most disabling disorders in all of medicine. It is estimated by the National Institute of Mental Health (NIMH) that 2.4 million people over the age of 18 in the US suffer from schizophrenia. This illness typically begins in adolescence and derails the formative goals of school, family, and work, leading to considerable suffering and disability and reduced life expectancy by about 20 years. Treatment outcomes are variable, and some people are successfully treated and reintegrated (i.e. go back to work

  13. Recent advances in understanding schizophrenia.

    PubMed

    Haller, Chiara S; Padmanabhan, Jaya L; Lizano, Paulo; Torous, John; Keshavan, Matcheri

    2014-01-01

    Schizophrenia is a highly disabling disorder whose causes remain to be better understood, and treatments have to be improved. However, several recent advances have been made in diagnosis, etiopathology, and treatment. Whereas reliability of diagnosis has improved with operational criteria, including Diagnostic and Statistical Manual of Mental Disorders, (DSM) Fifth Edition, validity of the disease boundaries remains unclear because of substantive overlaps with other psychotic disorders. Recent emphasis on dimensional approaches and translational bio-behavioral research domain criteria may eventually help move toward a neuroscience-based definition of schizophrenia. The etiology of schizophrenia is now thought to be multifactorial, with multiple small-effect and fewer large-effect susceptibility genes interacting with several environmental factors. These factors may lead to developmentally mediated alterations in neuroplasticity, manifesting in a cascade of neurotransmitter and circuit dysfunctions and impaired connectivity with an onset around early adolescence. Such etiopathological understanding has motivated a renewed search for novel pharmacological as well as psychotherapeutic targets. Addressing the core features of the illness, such as cognitive deficits and negative symptoms, and developing hypothesis-driven early interventions and preventive strategies are high-priority goals for the field. Schizophrenia is a severe, chronic mental disorder and is among the most disabling disorders in all of medicine. It is estimated by the National Institute of Mental Health (NIMH) that 2.4 million people over the age of 18 in the US suffer from schizophrenia. This illness typically begins in adolescence and derails the formative goals of school, family, and work, leading to considerable suffering and disability and reduced life expectancy by about 20 years. Treatment outcomes are variable, and some people are successfully treated and reintegrated (i.e. go back to work

  14. Recent advances in understanding psoriasis

    PubMed Central

    Eberle, Franziska C.; Brück, Jürgen; Holstein, Julia; Hirahara, Kiyoshi; Ghoreschi, Kamran

    2016-01-01

    T helper (Th) cells producing interleukin (IL)-17, IL-22, and tumor necrosis factor (TNF) form the key T cell population driving psoriasis pathogenesis. They orchestrate the inflammation in the skin that results in the proliferation of keratinocytes and endothelial cells. Besides Th17 cells, other immune cells that are capable of producing IL-17-associated cytokines participate in psoriatic inflammation. Recent advances in psoriasis research improved our understanding of the cellular and molecular players that are involved in Th17 pathology and inflammatory pathways in the skin. The inflammation-driving actions of TNF in psoriasis are already well known and antibodies against TNF are successful in the treatment of Th17-mediated psoriatic skin inflammation. A further key cytokine with potent IL-17-/IL-22-promoting properties is IL-23. Therapeutics directly neutralizing IL-23 or IL-17 itself are now extending the therapeutic spectrum of antipsoriatic agents and further developments are on the way. The enormous progress in psoriasis research allows us to control this Th17-mediated inflammatory skin disease in many patients. PMID:27158469

  15. Recent advances in understanding dengue

    PubMed Central

    Yacoub, Sophie; Mongkolsapaya, Juthathip; Screaton, Gavin

    2016-01-01

    Dengue is an emerging threat to billions of people worldwide. In the last 20 years, the incidence has increased four-fold and this trend appears to be continuing. Caused by one of four viral serotypes, dengue can present as a wide range of clinical phenotypes with the severe end of the spectrum being defined by a syndrome of capillary leak, coagulopathy, and organ impairment. The pathogenesis of severe disease is thought to be in part immune mediated, but the exact mechanisms remain to be defined. The current treatment of dengue relies on supportive measures with no licensed therapeutics available to date. There have been recent advances in our understanding of a number of areas of dengue research, of which the following will be discussed in this review: the drivers behind the global dengue pandemic, viral structure and epitope binding, risk factors for severe disease and its pathogenesis, as well as the findings of recent clinical trials including therapeutics and vaccines. We conclude with current and future dengue control measures and key areas for future research. PMID:26918159

  16. Recent advances in understanding apicomplexan parasites.

    PubMed

    Seeber, Frank; Steinfelder, Svenja

    2016-01-01

    Intracellular single-celled parasites belonging to the large phylum Apicomplexa are amongst the most prevalent and morbidity-causing pathogens worldwide. In this review, we highlight a few of the many recent advances in the field that helped to clarify some important aspects of their fascinating biology and interaction with their hosts. Plasmodium falciparum causes malaria, and thus the recent emergence of resistance against the currently used drug combinations based on artemisinin has been of major interest for the scientific community. It resulted in great advances in understanding the resistance mechanisms that can hopefully be translated into altered future drug regimens. Apicomplexa are also experts in host cell manipulation and immune evasion. Toxoplasma gondii and Theileria sp., besides Plasmodium sp., are species that secrete effector molecules into the host cell to reach this aim. The underlying molecular mechanisms for how these proteins are trafficked to the host cytosol ( T. gondii and Plasmodium) and how a secreted protein can immortalize the host cell ( Theileria sp.) have been illuminated recently. Moreover, how such secreted proteins affect the host innate immune responses against T. gondii and the liver stages of Plasmodium has also been unraveled at the genetic and molecular level, leading to unexpected insights. Methodological advances in metabolomics and molecular biology have been instrumental to solving some fundamental puzzles of mitochondrial carbon metabolism in Apicomplexa. Also, for the first time, the generation of stably transfected Cryptosporidium parasites was achieved, which opens up a wide variety of experimental possibilities for this understudied, important apicomplexan pathogen. PMID:27347391

  17. Recent advances in understanding apicomplexan parasites

    PubMed Central

    Seeber, Frank; Steinfelder, Svenja

    2016-01-01

    Intracellular single-celled parasites belonging to the large phylum Apicomplexa are amongst the most prevalent and morbidity-causing pathogens worldwide. In this review, we highlight a few of the many recent advances in the field that helped to clarify some important aspects of their fascinating biology and interaction with their hosts. Plasmodium falciparum causes malaria, and thus the recent emergence of resistance against the currently used drug combinations based on artemisinin has been of major interest for the scientific community. It resulted in great advances in understanding the resistance mechanisms that can hopefully be translated into altered future drug regimens. Apicomplexa are also experts in host cell manipulation and immune evasion. Toxoplasma gondii and Theileria sp., besides Plasmodium sp., are species that secrete effector molecules into the host cell to reach this aim. The underlying molecular mechanisms for how these proteins are trafficked to the host cytosol ( T. gondii and Plasmodium) and how a secreted protein can immortalize the host cell ( Theileria sp.) have been illuminated recently. Moreover, how such secreted proteins affect the host innate immune responses against T. gondii and the liver stages of Plasmodium has also been unraveled at the genetic and molecular level, leading to unexpected insights. Methodological advances in metabolomics and molecular biology have been instrumental to solving some fundamental puzzles of mitochondrial carbon metabolism in Apicomplexa. Also, for the first time, the generation of stably transfected Cryptosporidium parasites was achieved, which opens up a wide variety of experimental possibilities for this understudied, important apicomplexan pathogen. PMID:27347391

  18. Recent advances in understanding vitiligo

    PubMed Central

    Manga, Prashiela; Elbuluk, Nada; Orlow, Seth J.

    2016-01-01

    Vitiligo, an acquired depigmentation disorder, manifests as white macules on the skin and can cause significant psychological stress and stigmatization. Recent advances have shed light on key components that drive disease onset and progression as well as therapeutic approaches. Vitiligo can be triggered by stress to the melanin pigment-producing cells of the skin, the melanocytes. The triggers, which range from sunburn to mechanical trauma and chemical exposures, ultimately cause an autoimmune response that targets melanocytes, driving progressive skin depigmentation. The most significant progress in our understanding of disease etiology has been made on three fronts: (1) identifying cellular responses to stress, including antioxidant pathways and the unfolded protein response (UPR), as key players in disease onset, (2) characterizing immune responses that target melanocytes and drive disease progression, and (3) identifying major susceptibility genes. The current model for vitiligo pathogenesis postulates that oxidative stress causes cellular disruptions, including interruption of protein maturation in the endoplasmic reticulum (ER), leading to the activation of the UPR and expression of UPR-regulated chemokines such as interleukin 6 (IL-6) and IL-8. These chemokines recruit immune components to the skin, causing melanocytes to be targeted for destruction. Oxidative stress can further increase melanocyte targeting by promoting antigen presentation. Two key components of the autoimmune response that promote disease progression are the interferon (IFN)-γ/CXCL10 axis and IL-17-mediated responses. Several genome-wide association studies support a role for these pathways, with the antioxidant gene NRF2, UPR gene XBP1, and numerous immune-related genes including class I and class II major histocompatibility genes associated with a risk for developing vitiligo. Novel approaches to promote repigmentation in vitiligo are being investigated and may yield effective, long

  19. Understanding Femtosecond-Pulse Laser Damage through Fundamental Physics Simulations

    NASA Astrophysics Data System (ADS)

    Mitchell, Robert A., III

    It did not take long after the invention of the laser for the field of laser damage to appear. For several decades researchers have been studying how lasers damage materials, both for the basic scientific understanding of highly nonequilibrium processes as well as for industrial applications. Femtosecond pulse lasers create little collateral damage and a readily reproducible damage pattern. They are easily tailored to desired specifications and are particularly powerful and versatile tools, contributing even more industrial interest in the field. As with most long-standing fields of research, many theoretical tools have been developed to model the laser damage process, covering a wide range of complexities and regimes of applicability. However, most of the modeling methods developed are either too limited in spatial extent to model the full morphology of the damage crater, or incorporate only a small subset of the important physics and require numerous fitting parameters and assumptions in order to match values interpolated from experimental data. Demonstrated in this work is the first simulation method capable of fundamentally modeling the full laser damage process, from the laser interaction all the way through to the resolidification of the target, on a large enough scale that can capture the full morphology of the laser damage crater so as to be compared directly to experimental measurements instead of extrapolated values, and all without any fitting parameters. The design, implementation, and testing of this simulation technique, based on a modified version of the particle-in-cell (PIC) method, is presented. For a 60 fs, 1 mum wavelength laser pulse with fluences of 0.5 J/cm 2, 1.0 J/cm2, and 2.0 J/cm2 the resulting laser damage craters in copper are shown and, using the same technique applied to experimental crater morphologies, a laser damage fluence threshold is calculated of 0.15 J/cm2, consistent with current experiments performed under conditions similar

  20. Advancing Drought Understanding, Monitoring and Prediction

    NASA Technical Reports Server (NTRS)

    Mariotti, Annarita; Schubert, Siegfried D.; Mo, Kingtse; Peters-Lidard, Christa; Wood, Andy; Pulwarty, Roger; Huang, Jin; Barrie, Dan

    2013-01-01

    , focused and coordinated research efforts are needed, drawing from excellence across the broad drought research community. To meet this challenge, National Oceanic and Atmospheric Administration (NOAA)'s Drought Task Force was established in October 2011 with the ambitious goal of achieving significant new advances in the ability to understand, monitor, and predict drought over North America. The Task Force (duration of October 2011-September 2014) is an initiative of NOAA's Climate Program Office Modeling, Analysis, Predictions, and Projections (MAPP) program in partnership with NIDIS. It brings together over 30 leading MAPP-funded drought scientists from multiple academic and federal institutions [involves scientists from NOAA's research laboratories and centers, the National Aeronautics and Space Administration (NASA), U.S. Department of Agriculture, National Center for Atmospheric Research (NCAR), and many universities] in a concerted research effort that builds on individual MAPP research projects. These projects span the wide spectrum of drought research needed to make fundamental advances, from those aimed at the basic understanding of drought mechanisms to those aimed at testing new drought monitoring and prediction tools for operational and service purposes (as part of NCEP's Climate Test Bed). The Drought Task Force provides focus and coordination to MAPP drought research activities and also facilitates synergies with other national and international drought research efforts, including those by the GDIS.

  1. Advances in understanding cartilage remodeling

    PubMed Central

    Li, Yefu; Xu, Lin

    2015-01-01

    Cartilage remodeling is currently among the most popular topics in osteoarthritis research. Remodeling includes removal of the existing cartilage and replacement by neo-cartilage. As a loss of balance between removal and replacement of articular cartilage develops (particularly, the rate of removal surpasses the rate of replacement), joints will begin to degrade. In the last few years, significant progress in molecular understanding of the cartilage remodeling process has been made. In this brief review, we focus on the discussion of some current “controversial” observations in articular cartilage degeneration: (1) the biological effect of transforming growth factor-beta 1 on developing and mature articular cartilages, (2) the question of whether aggrecanase 1 (ADAMTS4) and aggrecanase 2 (ADAMTS5) are key enzymes in articular cartilage destruction, and (3) chondrocytes versus chondron in the development of osteoarthritis. It is hoped that continued discussion and investigation will follow to better clarify these topics. Clarification will be critical for those in search of novel therapeutic targets for the treatment of osteoarthritis. PMID:26380073

  2. Toward a Fundamental Understanding of Nuclear Reactions and Exotic Nuclei

    NASA Astrophysics Data System (ADS)

    Quaglioni, Sofia; Hupin, Guillaume; Langhammer, Joachim; Romero-Redondo, Carolina; Schuster, Micah D.; Johnson, Calvin W.; Navrátil, Petr; Roth, Robert

    Nuclear systems near the drip lines offer an exciting opportunity to advance our understanding of the interactions among nucleons, which has so far been mostly based on the study of stable nuclei. However, this is not a goal devoid of challenges. From a theoretical standpoint, it requires the capability to address within an ab initio framework not only bound, but also resonant and scattering states, all of which can be strongly coupled. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from Quantum Chromodynamics employing Hamiltonians constructed within chiral effective field theory. In this contribution, we present a brief overview of one of such methods, the ab initio no-core shell model with continuum, and its applications to nucleon and deuterium scattering on light nuclei. The first investigation of the low-lying continuum spectrum of 6He within an ab initio framework that encompasses the 4He + n + n three-cluster dynamics characterizing its lowest particle-decay channel will also be briefly presented.

  3. Advances in Understanding the Biosynthesis of Fumonisins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumonisins are a group of economically important mycotoxins that are derived polyketides. Since the cloning of the fumonisin polyketide synthase (PKS) gene from Fusarium verticillioides in 1999, significant advances have been made in understanding the molecular mechanisms for fumonisin biosynthesis...

  4. Fundamental understanding and development of low-cost, high-efficiency silicon solar cells

    SciTech Connect

    ROHATGI,A.; NARASIMHA,S.; MOSCHER,J.; EBONG,A.; KAMRA,S.; KRYGOWSKI,T.; DOSHI,P.; RISTOW,A.; YELUNDUR,V.; RUBY,DOUGLAS S.

    2000-05-01

    The overall objectives of this program are (1) to develop rapid and low-cost processes for manufacturing that can improve yield, throughput, and performance of silicon photovoltaic devices, (2) to design and fabricate high-efficiency solar cells on promising low-cost materials, and (3) to improve the fundamental understanding of advanced photovoltaic devices. Several rapid and potentially low-cost technologies are described in this report that were developed and applied toward the fabrication of high-efficiency silicon solar cells.

  5. Enhancing Cognitive Understanding to Improve Fundamental Movement Skills

    ERIC Educational Resources Information Center

    Drost, Daniel K.; Todorovich, John R.

    2013-01-01

    The development of fundamental movement skills in physical education is an important contributor toward children's' lifetime interest and participation in physical activity. Physical education teachers and their curricula follow national and state standards to provide learning experiences and instruction that support the acquisition of…

  6. Understanding the Fundamental Connection Between Electronic Correlation and Decoherence.

    PubMed

    Kar, Arnab; Chen, Liping; Franco, Ignacio

    2016-05-01

    We introduce a theory that exposes the fundamental and previously overlooked connection between the correlation among electrons and the degree of quantum coherence of electronic states in matter. For arbitrary states, the effects only decouple when the electronic dynamics induced by the nuclear bath is pure-dephasing in nature such that [H(S),H(SB)] = 0, where H(S) is the electronic Hamiltonian and H(SB) is the electron-nuclear coupling. We quantitatively illustrate this connection via exact simulations of a Hubbard-Holstein molecule using the Hierarchical Equations of Motion that show that increasing the degree of electronic interactions can enhance or suppress the rate of electronic coherence loss. PMID:27075605

  7. A brief review: history to understand fundamentals of electrocardiography.

    PubMed

    AlGhatrif, Majd; Lindsay, Joseph

    2012-01-01

    The last decade of the 19th century witnessed the rise of a new era in which physicians used technology along with classical history taking and physical examination for the diagnosis of heart disease. The introduction of chest x-rays and the electrocardiograph (electrocardiogram) provided objective information about the structure and function of the heart. In the first half of the 20th century, a number of innovative individuals set in motion a fascinating sequence of discoveries and inventions that led to the 12-lead electrocardiogram, as we know it now. Electrocardiography, nowadays, is an essential part of the initial evaluation for patients presenting with cardiac complaints. As a first line diagnostic tool, health care providers at different levels of training and expertise frequently find it imperative to interpret electrocardiograms. It is likely that an understanding of the electrical basis of electrocardiograms would reduce the likelihood of error. An understanding of the disorders behind electrocardiographic phenomena could reduce the need for memorizing what may seem to be an endless list of patterns. In this article, we will review the important steps in the evolution of electrocardiogram. As is the case in most human endeavors, an understanding of history enables one to deal effectively with the present. PMID:23882360

  8. A brief review: history to understand fundamentals of electrocardiography

    PubMed Central

    AlGhatrif, Majd; Lindsay, Joseph

    2012-01-01

    The last decade of the 19th century witnessed the rise of a new era in which physicians used technology along with classical history taking and physical examination for the diagnosis of heart disease. The introduction of chest x-rays and the electrocardiograph (electrocardiogram) provided objective information about the structure and function of the heart. In the first half of the 20th century, a number of innovative individuals set in motion a fascinating sequence of discoveries and inventions that led to the 12-lead electrocardiogram, as we know it now. Electrocardiography, nowadays, is an essential part of the initial evaluation for patients presenting with cardiac complaints. As a first line diagnostic tool, health care providers at different levels of training and expertise frequently find it imperative to interpret electrocardiograms. It is likely that an understanding of the electrical basis of electrocardiograms would reduce the likelihood of error. An understanding of the disorders behind electrocardiographic phenomena could reduce the need for memorizing what may seem to be an endless list of patterns. In this article, we will review the important steps in the evolution of electrocardiogram. As is the case in most human endeavors, an understanding of history enables one to deal effectively with the present. PMID:23882360

  9. Recent advances in understanding hepatitis C

    PubMed Central

    Ploss, Alexander

    2016-01-01

    The past decade has seen tremendous progress in understanding hepatitis C virus (HCV) biology and its related disease, hepatitis C. Major advances in characterizing viral replication have led to the development of direct-acting anti-viral therapies that have considerably improved patient treatment outcome and can even cure chronic infection. However, the high cost of these treatments, their low barrier to viral resistance, and their inability to prevent HCV-induced liver cancer, along with the absence of an effective HCV vaccine, all underscore the need for continued efforts to understand the biology of this virus. Moreover, beyond informing therapies, enhanced knowledge of HCV biology is itself extremely valuable for understanding the biology of related viruses, such as dengue virus, which is becoming a growing global health concern. Major advances have been realized over the last few years in HCV biology and pathogenesis, such as the discovery of the envelope glycoprotein E2 core structure, the generation of the first mouse model with inheritable susceptibility to HCV, and the characterization of virus-host interactions that regulate viral replication or innate immunity. Here, we review the recent findings that have significantly advanced our understanding of HCV and highlight the major challenges that remain. PMID:26918166

  10. Recent advances in understanding hepatitis C.

    PubMed

    Douam, Florian; Ding, Qiang; Ploss, Alexander

    2016-01-01

    The past decade has seen tremendous progress in understanding hepatitis C virus (HCV) biology and its related disease, hepatitis C. Major advances in characterizing viral replication have led to the development of direct-acting anti-viral therapies that have considerably improved patient treatment outcome and can even cure chronic infection. However, the high cost of these treatments, their low barrier to viral resistance, and their inability to prevent HCV-induced liver cancer, along with the absence of an effective HCV vaccine, all underscore the need for continued efforts to understand the biology of this virus. Moreover, beyond informing therapies, enhanced knowledge of HCV biology is itself extremely valuable for understanding the biology of related viruses, such as dengue virus, which is becoming a growing global health concern. Major advances have been realized over the last few years in HCV biology and pathogenesis, such as the discovery of the envelope glycoprotein E2 core structure, the generation of the first mouse model with inheritable susceptibility to HCV, and the characterization of virus-host interactions that regulate viral replication or innate immunity. Here, we review the recent findings that have significantly advanced our understanding of HCV and highlight the major challenges that remain. PMID:26918166

  11. Shape direction and size control of novel nanostructures: Towards a fundamental understanding of growth

    NASA Astrophysics Data System (ADS)

    Leong, G. Jeremy

    Shape control of metal nanoparticles has had a great deal of attention in the past decade due to the enhanced catalytic properties based on structure and surface faceting. Numerous methods have been developed to synthesize various nanostructures that make more efficient use of the active surfaces by tuning porosity, shapes, sizes, and facets by adding foreign ions which promote or restrict growth on specific sites; however, a fundamental mechanistic understanding of how and why ions and other synthetic parameters direct growth resulting in specific shapes and porosity have only been hypothesized. Herein, we first demonstrate the importance of shaped metal nanoparticles in terms of active sites in Au icosahedra, which motivates a full literature review of shaped Pt nanostructures. The conclusions regarding need for understanding towards growth systems motivates the study of both direct (wet chemical reduction) and indirect (galvanic displacement) synthesis techniques, which is then followed by the probing of nanoparticle growth kinetics as well as mesopore expansion in silica. Synergistic capabilities of computationally-guided synthetic routes as proposed by the Materials Genome Initiative (MGI) are demonstrated by testing hypotheses, then utilizing experimental insight from platinum systems to predict the growth of faceted palladium nanocrystals. Mechanistic insight on growth kinetics can be elucidated by studying the role of directing ions during the growth process, thereby obtaining a general fundamental understanding of directed nanoparticle formation. The pore expansion mechanisms in mesoporous materials via hydrothermal treatments allows us to understand pore sizes as a function of solution etching, thus giving rise to size-dependent separation and sequestration applications. Understanding structure and activity relationships of our resulting products will assist in the synthesis of next generation materials with enhanced properties, thereby advancing the

  12. Improving conservation outcomes with a new paradigm for understanding species’ fundamental and realized adaptive capacity

    USGS Publications Warehouse

    Beever, Erik; O’Leary, John; Mengelt, Claudia; West, Jordan M.; Julius, Susan; Green, Nancy; Magness, Dawn; Petes, Laura E.; Stein, Bruce A.; Nicotra, Adrienne B; Hellmann, Jessica J; Robertson, Amanda L; Staudinger, Michelle D.; Rosenberg, Andrew A.; Babij, Eleanora; Brennan, Jean; Schuurman, Gregor W; Hofmann, Gretchen E

    2016-01-01

    Worldwide, many species are responding to ongoing climate change with shifts in distribution, abundance, phenology, or behavior. Consequently, natural-resource managers face increasingly urgent conservation questions related to biodiversity loss, expansion of invasive species, and deteriorating ecosystem services. We argue that our ability to address these questions is hampered by the lack of explicit consideration of species’ adaptive capacity (AC). AC is the ability of a species or population to cope with climatic changes and is characterized by three fundamental components: phenotypic plasticity, dispersal ability, and genetic diversity. However, few studies simultaneously address all elements; often, AC is confused with sensitivity or omitted altogether from climate-change vulnerability assessments. Improved understanding, consistent definition, and comprehensive evaluations of AC are needed. Using classic ecological-niche theory as an analogy, we propose a new paradigm that considers fundamental and realized AC: the former reflects aspects inherent to species, whereas the latter denotes how extrinsic factors constrain AC to what is actually expressed or observed. Through this conceptualization, we identify ecological attributes contributing to AC, outline areas of research necessary to advance understanding of AC, and provide examples demonstrating how the inclusion of AC can better inform conservation and natural-resource management.

  13. Recent advances in understanding and managing asthma.

    PubMed

    Loo, Su-Ling; Wark, Peter A B

    2016-01-01

    This review highlights the important articles published in the area of asthma research from January 2015 to July 2016. In basic science, significant advances have been made in understanding the link between the innate immune response and type II acquired immune responses in asthma and the role of the airway epithelium. Novel information continues to emerge with regard to the pathogenesis and heterogeneity of severe asthma. There have been important translational clinical trials in the areas of childhood asthma, treatment of allergy to improve asthma outcomes, and improving drug delivery to optimize the management of asthma. In addition, there are increasing data concerning the application of biological agents to the management of severe asthma. This body of work discusses the most notable advances in the understanding and management of asthma. PMID:27610226

  14. Recent advances in understanding and managing asthma

    PubMed Central

    Loo, Su-Ling; Wark, Peter A.B.

    2016-01-01

    This review highlights the important articles published in the area of asthma research from January 2015 to July 2016. In basic science, significant advances have been made in understanding the link between the innate immune response and type II acquired immune responses in asthma and the role of the airway epithelium. Novel information continues to emerge with regard to the pathogenesis and heterogeneity of severe asthma. There have been important translational clinical trials in the areas of childhood asthma, treatment of allergy to improve asthma outcomes, and improving drug delivery to optimize the management of asthma. In addition, there are increasing data concerning the application of biological agents to the management of severe asthma. This body of work discusses the most notable advances in the understanding and management of asthma. PMID:27610226

  15. Advances in understanding and treating premature ejaculation.

    PubMed

    Saitz, Theodore R; Serefoglu, Ege Can

    2015-11-01

    Over the past several years, many advances have been made in our understanding of the epidemiology, pathophysiology, and management of premature ejaculation. Newly developed definitions of premature ejaculation are now available, and our perception of the classification, prevalence, aetiological factors, and treatment options for premature ejaculation have evolved. Despite ongoing research, there remains much to be learned about all aspects of this common sexual disorder, in particular effective clinical diagnosis and treatment options. PMID:26502991

  16. Recent advances in understanding and managing rhabdomyosarcoma

    PubMed Central

    Hiniker, Susan M.

    2015-01-01

    Rhabdomyosarcoma is the most common childhood soft tissue sarcoma and the fourth most common pediatric solid tumor. For most patients, treatment consists of a multimodality approach, including chemotherapy, surgery, and/or radiotherapy. To guide treatment, patients with rhabdomyosarcoma are risk stratified based on a number of factors. These factors include clinical group, which depends largely on the extent of resection and nodal involvement, and stage, which takes into account tumor size, invasion, nodal involvement, and disease site. Histology of the tumor and age at diagnosis are also factored into risk stratification. Recent advances in understanding the biology of the disease have allowed for the further sub-classification of rhabdomyosarcoma. In addition, elucidation of additional clinical features associated with poor prognosis has allowed for better understanding of risk and provides more clarity regarding those patients who require more intensive therapy. Many areas of active investigation are ongoing, including the following: further delineation of the biological underpinnings of the various disease subtypes with the possibility of molecularly targeted therapy; a better understanding of clinical risk factors, including the evaluation and management of potentially involved lymph nodes; determination of the appropriate role of post-treatment imaging and assessment of response to therapy; and incorporation of advanced radiotherapeutic techniques, including conformal intensity-modulated photon and proton therapy. PMID:26097732

  17. Fundamentals of Melt-Water Interfacial Transport Phenomena: Improved Understanding for Innovative Safety Technologies in ALWRs

    SciTech Connect

    M. Anderson; M. Corradini; K.Y. Bank; R. Bonazza; D. Cho

    2005-04-26

    The interaction and mixing of high-temperature melt and water is the important technical issue in the safety assessment of water-cooled reactors to achieve ultimate core coolability. For specific advanced light water reactor (ALWR) designs, deliberate mixing of the core-melt and water is being considered as a mitigative measure, to assure ex-vessel core coolability. The goal of this work is to provide the fundamental understanding needed for melt-water interfacial transport phenomena, thus enabling the development of innovative safety technologies for advanced LWRs that will assure ex-vessel core coolability. The work considers the ex-vessel coolability phenomena in two stages. The first stage is the melt quenching process and is being addressed by Argonne National Lab and University of Wisconsin in modified test facilities. Given a quenched melt in the form of solidified debris, the second stage is to characterize the long-term debris cooling process and is being addressed by Korean Maritime University in via test and analyses. We then address the appropriate scaling and design methodologies for reactor applications.

  18. Advances in understanding erythropoiesis: evolving perspectives.

    PubMed

    Nandakumar, Satish K; Ulirsch, Jacob C; Sankaran, Vijay G

    2016-04-01

    Red blood cells (RBCs) are generated from haematopoietic stem and progenitor cells (HSPCs) through the step-wise process of differentiation known as erythropoiesis. In this review, we discuss our current understanding of erythropoiesis and highlight recent advances in this field. During embryonic development, erythropoiesis occurs in three distinct waves comprising first, the yolk sac-derived primitive RBCs, followed sequentially by the erythro-myeloid progenitor (EMP) and HSPC-derived definitive RBCs. Recent work has highlighted the complexity and variability that may exist in the hierarchical arrangement of progenitors responsible for erythropoiesis. Using recently defined cell surface markers, it is now possible to enrich for erythroid progenitors and precursors to a much greater extent than has been possible before. While a great deal of knowledge has been gained on erythropoiesis from model organisms, our understanding of this process is currently being refined through human genetic studies. Genes mutated in erythroid disorders can now be identified more rapidly by the use of next-generation sequencing techniques. Genome-wide association studies on erythroid traits in healthy populations have also revealed new modulators of erythropoiesis. All of these recent developments have significant promise not only for increasing our understanding of erythropoiesis, but also for improving our ability to intervene when RBC production is perturbed in disease. PMID:26846448

  19. Recent Advances in Understanding and Engineering Polyketide Synthesis

    PubMed Central

    Zhang, Wenjun; Liu, Joyce

    2016-01-01

    Polyketides are a diverse group of natural products that form the basis of many important drugs. The engineering of the polyketide synthase (PKS) enzymes responsible for the formation of these compounds has long been considered to have great potential for producing new bioactive molecules. Recent advances in this field have contributed to the understanding of this powerful and complex enzymatic machinery, particularly with regard to domain activity and engineering, unique building block formation and incorporation, and programming rules and limitations. New developments in tools for in vitro biochemical analysis, full-length megasynthase structural studies, and in vivo heterologous expression will continue to improve our fundamental understanding of polyketide synthesis as well as our ability to engineer the production of polyketides. PMID:26962443

  20. Recent advances in understanding and managing cholestasis

    PubMed Central

    Wagner, Martin; Trauner, Michael

    2016-01-01

    Cholestatic liver diseases are hereditary or acquired disorders with impaired hepatic excretion and enterohepatic circulation of bile acids and other cholephiles. The distinct pathological mechanisms, particularly for the acquired forms of cholestasis, are not fully revealed, but advances in the understanding of the molecular mechanisms and identification of key regulatory mechanisms of the enterohepatic circulation of bile acids have unraveled common and central mechanisms, which can be pharmacologically targeted. This overview focuses on the central roles of farnesoid X receptor, fibroblast growth factor 19, and apical sodium-dependent bile acid transporter for the enterohepatic circulation of bile acids and their potential as new drug targets for the treatment of cholestatic liver disease. PMID:27134744

  1. Recent advances in understanding multiple myeloma.

    PubMed

    Dhakal, Binod; Girnius, Saulius; Hari, Parameswaran

    2016-01-01

    There have been major recent advancements in the understanding and management of multiple myeloma. Diagnostic criteria have been revised and former ultra-high-risk smoldering multiple myeloma is now considered multiple myeloma in need of treatment. Understanding clonal progression, evolution, and tides not only has helped elucidate the disease behavior but might help expand therapeutic choices in order to select appropriate treatment for patients. Unprecedented response rates with modern triplet induction therapies containing proteasome inhibitor and immunomodulators have made this approach standard for initial treatment. The US Food and Drug Administration approved four new drugs (two targeted antibodies and two oral agents) in 2015 in relapsed/refractory multiple myeloma and these drugs along with the other already-available drugs have now increased the choices of regimens. Even drugs without single-agent activity, such as panobinostat and elotuzumab, have an important role, especially in the proteasome inhibitor refractory setting. Recent studies done in the context of novel agent induction suggest that high-dose therapy followed by autologous transplant continues to improve response rates and progression-free survival, thus underscoring their role in transplant-eligible patients. Evolving paradigms in the treatment of multiple myeloma include newer promising immune approaches, such as adoptive cellular therapies, vaccines, or antibody-based immune manipulations. Though multiple myeloma is still considered incurable, it is clear that with the improved understanding of disease biology and clonal architecture of relapse combined with the availability of multi-targeted approaches, we are ever closer to a lasting cure or transformation into indolent and long-lasting disease courses or both. PMID:27610224

  2. Recent advances in understanding multiple myeloma

    PubMed Central

    Dhakal, Binod; Girnius, Saulius; Hari, Parameswaran

    2016-01-01

    There have been major recent advancements in the understanding and management of multiple myeloma. Diagnostic criteria have been revised and former ultra-high-risk smoldering multiple myeloma is now considered multiple myeloma in need of treatment. Understanding clonal progression, evolution, and tides not only has helped elucidate the disease behavior but might help expand therapeutic choices in order to select appropriate treatment for patients. Unprecedented response rates with modern triplet induction therapies containing proteasome inhibitor and immunomodulators have made this approach standard for initial treatment. The US Food and Drug Administration approved four new drugs (two targeted antibodies and two oral agents) in 2015 in relapsed/refractory multiple myeloma and these drugs along with the other already-available drugs have now increased the choices of regimens. Even drugs without single-agent activity, such as panobinostat and elotuzumab, have an important role, especially in the proteasome inhibitor refractory setting. Recent studies done in the context of novel agent induction suggest that high-dose therapy followed by autologous transplant continues to improve response rates and progression-free survival, thus underscoring their role in transplant-eligible patients. Evolving paradigms in the treatment of multiple myeloma include newer promising immune approaches, such as adoptive cellular therapies, vaccines, or antibody-based immune manipulations. Though multiple myeloma is still considered incurable, it is clear that with the improved understanding of disease biology and clonal architecture of relapse combined with the availability of multi-targeted approaches, we are ever closer to a lasting cure or transformation into indolent and long-lasting disease courses or both. PMID:27610224

  3. Advances in Understanding and Managing Chronic Urticaria

    PubMed Central

    Moolani, Yasmin; Lynde, Charles; Sussman, Gordon

    2016-01-01

    There have been recent advances in the classification and management of chronic urticaria. The new term chronic spontaneous urticaria (CSU) has replaced chronic idiopathic urticaria and chronic autoimmune urticaria. In addition, chronic inducible urticaria (CINDU) has replaced physical urticaria and includes other forms of inducible urticaria, such as cholinergic and aquagenic urticaria. Furthermore, novel research has resulted in a new understanding with guidelines being revised in the past year by both the American Academy of Allergy, Asthma, and Immunology (AAAAI) and the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA 2LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO). There are some differences in the recommendations, which will be discussed, but the core updates are common to both groups. The basic treatment for chronic urticaria involves second-generation non-sedating non-impairing H 1 antihistamines as first-line treatment. This is followed by up to a 4-fold increase in the licensed dose of these H 1 antihistamines. The major therapeutic advance in recent years has been in third-line treatment with omalizumab, a humanized monoclonal anti-immunoglobulin E (anti-IgE) antibody that prevents binding of IgE to the high-affinity IgE receptor. Several multicenter randomized controlled trials have shown safety and efficacy of omalizumab for CSU. There are also some small studies showing efficacy of omalizumab in CINDU. While there were previously many treatment options which were lacking in strong evidence, we are moving into an era where the treatment algorithm for chronic urticaria is simplified and contains more evidence-based, effective, and less toxic treatment options. PMID:26949520

  4. Advances in Understanding and Managing Chronic Urticaria.

    PubMed

    Moolani, Yasmin; Lynde, Charles; Sussman, Gordon

    2016-01-01

    There have been recent advances in the classification and management of chronic urticaria. The new term chronic spontaneous urticaria (CSU) has replaced chronic idiopathic urticaria and chronic autoimmune urticaria. In addition, chronic inducible urticaria (CINDU) has replaced physical urticaria and includes other forms of inducible urticaria, such as cholinergic and aquagenic urticaria. Furthermore, novel research has resulted in a new understanding with guidelines being revised in the past year by both the American Academy of Allergy, Asthma, and Immunology (AAAAI) and the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA (2)LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO). There are some differences in the recommendations, which will be discussed, but the core updates are common to both groups. The basic treatment for chronic urticaria involves second-generation non-sedating non-impairing H 1 antihistamines as first-line treatment. This is followed by up to a 4-fold increase in the licensed dose of these H 1 antihistamines. The major therapeutic advance in recent years has been in third-line treatment with omalizumab, a humanized monoclonal anti-immunoglobulin E (anti-IgE) antibody that prevents binding of IgE to the high-affinity IgE receptor. Several multicenter randomized controlled trials have shown safety and efficacy of omalizumab for CSU. There are also some small studies showing efficacy of omalizumab in CINDU. While there were previously many treatment options which were lacking in strong evidence, we are moving into an era where the treatment algorithm for chronic urticaria is simplified and contains more evidence-based, effective, and less toxic treatment options. PMID:26949520

  5. Parachute systems technology: Fundamentals, concepts, and applications: Advanced parachute design

    SciTech Connect

    Peterson, C.W.; Johnson, D.W.

    1987-01-01

    Advances in high-performance parachute systems and the technologies needed to design them are presented in this paper. New parachute design and performance prediction codes are being developed to assist the designer in meeting parachute system performance requirements after a minimum number of flight tests. The status of advanced design codes under development at Sandia National Laboratories is summarized. An integral part of parachute performance prediction is the rational use of existing test data. The development of a data base for parachute design has been initiated to illustrate the effects of inflated diameter, geometric porosity, reefing line length, suspension line length, number of gores, and number of ribbons on parachute drag. Examples of advancements in parachute materials are presented, and recent problems with Mil-Spec broadgoods are reviewed. Finally, recent parachute systems tested at Sandia are summarized to illustrate new uses of old parachutes, new parachute configurations, and underwater recovery of payloads.

  6. Understanding Fundamental Material Degradation Processes in High Temperature Aggressive Chemomechanical Environments

    SciTech Connect

    Stubbins, James; Gewirth, Andrew; Sehitoglu, Huseyin; Sofronis, Petros; Robertson, Ian

    2014-01-16

    The objective of this project is to develop a fundamental understanding of the mechanisms that limit materials durability for very high-temperature applications. Current design limitations are based on material strength and corrosion resistance. This project will characterize the interactions of high-temperature creep, fatigue, and environmental attack in structural metallic alloys of interest for the very high-temperature gas-cooled reactor (VHTR) or Next–Generation Nuclear Plant (NGNP) and for the associated thermo-chemical processing systems for hydrogen generation. Each of these degradation processes presents a major materials design challenge on its own, but in combination, they can act synergistically to rapidly degrade materials and limit component lives. This research and development effort will provide experimental results to characterize creep-fatigue-environment interactions and develop predictive models to define operation limits for high-temperature structural material applications. Researchers will study individually and in combination creep-fatigue-environmental attack processes in Alloys 617, 230, and 800H, as well as in an advanced Ni-Cr oxide dispersion strengthened steel (ODS) system. For comparison, the study will also examine basic degradation processes in nichrome (Ni-20Cr), which is a basis for most high-temperature structural materials, as well as many of the superalloys. These materials are selected to represent primary candidate alloys, one advanced developmental alloy that may have superior high-temperature durability, and one model system on which basic performance and modeling efforts can be based. The research program is presented in four parts, which all complement each other. The first three are primarily experimental in nature, and the last will tie the work together in a coordinated modeling effort. The sections are (1) dynamic creep-fatigue-environment process, (2) subcritical crack processes, (3) dynamic corrosion – crack

  7. Recent advances in understanding idiopathic pulmonary fibrosis

    PubMed Central

    Daccord, Cécile; Maher, Toby M.

    2016-01-01

    Despite major research efforts leading to the recent approval of pirfenidone and nintedanib, the dismal prognosis of idiopathic pulmonary fibrosis (IPF) remains unchanged. The elaboration of international diagnostic criteria and disease stratification models based on clinical, physiological, radiological, and histopathological features has improved the accuracy of IPF diagnosis and prediction of mortality risk. Nevertheless, given the marked heterogeneity in clinical phenotype and the considerable overlap of IPF with other fibrotic interstitial lung diseases (ILDs), about 10% of cases of pulmonary fibrosis remain unclassifiable. Moreover, currently available tools fail to detect early IPF, predict the highly variable course of the disease, and assess response to antifibrotic drugs. Recent advances in understanding the multiple interrelated pathogenic pathways underlying IPF have identified various molecular phenotypes resulting from complex interactions among genetic, epigenetic, transcriptional, post-transcriptional, metabolic, and environmental factors. These different disease endotypes appear to confer variable susceptibility to the condition, differing risks of rapid progression, and, possibly, altered responses to therapy. The development and validation of diagnostic and prognostic biomarkers are necessary to enable a more precise and earlier diagnosis of IPF and to improve prediction of future disease behaviour. The availability of approved antifibrotic therapies together with potential new drugs currently under evaluation also highlights the need for biomarkers able to predict and assess treatment responsiveness, thereby allowing individualised treatment based on risk of progression and drug response. This approach of disease stratification and personalised medicine is already used in the routine management of many cancers and provides a potential road map for guiding clinical care in IPF. PMID:27303645

  8. Fundamental limits on beam stability at the Advanced Photon Source.

    SciTech Connect

    Decker, G. A.

    1998-06-18

    Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.

  9. Filling "Na Puka" with PUFM: Empowering Teachers with Profound Understanding of Fundamental Mathematics

    ERIC Educational Resources Information Center

    Monroe, Eula Ewing; Bailey, John; Mitchell, Barry; AhSue, Yvonne

    2011-01-01

    This paper reports results from a Mathematics and Science Partnership grant designed primarily to help teachers from six elementary schools on the North Shore of O'ahu develop a profound understanding of fundamental mathematics (PUFM) (Ma, 1999). Five of these schools had not met minimum requirements under the No Child Left Behind Act; among them…

  10. Fundamental issues, recent advances, and future directions in myodynamics.

    PubMed

    Hatze, H

    2002-12-01

    A state-of-the-art report is presented on recent progress in selected areas of myodynamics, but also on problems that severely hamper the further development of the discipline. Significant advances have been made in elucidating the force-producing interaction between actin and the myosin-S1-subunit, including the localization of the most probable molecular site of power stroke initiation. Concerning the architecture of the myostructures, strong experimental evidence has accumulated for numerous intra-, inter-, and extramuscular pathways for lateral force transmission in addition to the serial sarcomere-to-sarcomere myotendinous path. It is shown that contemporary muscle models are inadequate in most respects and lag far behind the requirements an appropriate myodynamic model should fulfil. A similar comment applies to the current approaches designed to solve the myoskeletal indeterminacy problem. These formulations neglect myodynamic properties and do not allow for the implementation of biologically realistic objective functions. The solutions currently obtained are highly unsatisfactory. New research directions to rectify these situations are suggested, also with regard to the identification of subject-specific myodynamic parameters. PMID:12435541

  11. Fundamental studies of structure borne noise for advanced turboprop applications

    NASA Technical Reports Server (NTRS)

    Eversman, W.; Koval, L. R.

    1985-01-01

    The transmission of sound generated by wing-mounted, advanced turboprop engines into the cabin interior via structural paths is considered. The structural model employed is a beam representation of the wing box carried into the fuselage via a representative frame type of carry through structure. The structure for the cabin cavity is a stiffened shell of rectangular or cylindrical geometry. The structure is modelled using a finite element formulation and the acoustic cavity is modelled using an analytical representation appropriate for the geometry. The structural and acoustic models are coupled by the use of hard wall cavity modes for the interior and vacuum structural modes for the shell. The coupling is accomplished using a combination of analytical and finite element models. The advantage is the substantial reduction in dimensionality achieved by modelling the interior analytically. The mathematical model for the interior noise problem is demonstrated with a simple plate/cavity system which has all of the features of the fuselage interior noise problem.

  12. Recent progress in the fundamental understanding of hydrophilic interaction chromatography (HILIC).

    PubMed

    Guo, Yong

    2015-10-01

    With the exponential growth in the application of the HILIC technique, there has been a significant progress in understanding the fundamental aspects of hydrophilic interaction chromatography. The experimental studies tend to be more extensive in terms of the number of stationary phases investigated and the number of probe compounds employed in comparison with the earlier studies; and more theoretical studies in quantitative structure retention relationship (QSRR) and molecular dynamics simulations have also been published and provide molecular-level insights into the retention mechanism. This review focuses on the recent progress in understanding the retention mechanism, retention models, selectivity, and the kinetic performance of HILIC. A better understanding of these fundamental aspects will undoubtedly facilitate more applications of this chromatographic technique in a wider range of fields. PMID:26221630

  13. Recent advances in understanding and treating ARDS

    PubMed Central

    Baron, Rebecca M.; Levy, Bruce D.

    2016-01-01

    Acute respiratory distress syndrome represents a complex syndrome with considerable morbidity and mortality, for which there exist no targeted treatment strategies. However, recent advances in clinical care have improved outcomes, and we will review a number of these approaches here, as well as explore the mechanisms underlying the benefit of intervention that might point us in the direction toward future treatment and preventive strategies for this devastating syndrome. PMID:27158460

  14. Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications.

    SciTech Connect

    Swain; Greg M.

    2009-04-13

    The original funding under this project number was awarded for a period 12/1999 until 12/2002 under the project title Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications. The project was extended until 06/2003 at which time a renewal proposal was awarded for a period 06/2003 until 06/2008 under the project title Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes. The work under DE-FG02-01ER15120 was initiated about the time the PI moved his research group from the Department of Chemistry at Utah State University to the Department of Chemistry at Michigan State University. This DOE-funded research was focused on (i) understanding structure-function relationships at boron-doped diamond thin-film electrodes, (ii) understanding metal phase formation on diamond thin films and developing electrochemical approaches for producing highly dispersed electrocatalyst particles (e.g., Pt) of small nominal particle size, (iii) studying the electrochemical activity of the electrocatalytic electrodes for hydrogen oxidation and oxygen reduction and (iv) conducting the initial synthesis of high surface area diamond powders and evaluating their electrical and electrochemical properties when mixed with a Teflon binder.

  15. Advances in understanding and managing bullous pemphigoid

    PubMed Central

    Zhao, Cathy Y.; Murrell, Dedee F.

    2015-01-01

    Bullous pemphigoid (BP) is the commonest subtype of autoimmune blistering disease in most countries of the world. It occurs most frequently in elderly patients and is characterised clinically by large, tense blisters in the skin preceded by urticarial plaques and pruritus. Immunopathologically, it is characterised by autoantibodies directed against the 180 kD antigen (BP180) and the 230 kD antigen (BP230). New knowledge regarding BP is being continually uncovered. This article reviews the recent advances in BP, including newer diagnostic tests, standardised outcome measures and emerging therapeutic options, as well as the evidence supporting their use. PMID:26918143

  16. Recent advances in understanding and treating vasculitis

    PubMed Central

    Koster, Matthew J.; Warrington, Kenneth J.

    2016-01-01

    Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are near universally fatal conditions if untreated. Although effective therapeutic options are available for these diseases, treatment regimens are associated with both short- and long-term adverse effects. The recent identification of effective B-cell-targeted therapy with an anti-CD20 monoclonal antibody has transformed the treatment landscape of AAV. Questions, nevertheless, remain regarding the appropriate timing, dose, frequency, duration, and long-term effects of treatment. The aim of this article is to provide an overview of the current information, recent advances, ongoing clinical trials, and future treatment possibilities in AAV. PMID:27347395

  17. Advances in understanding paternally transmitted Chromosomal Abnormalities

    SciTech Connect

    Marchetti, F; Sloter, E; Wyrobek, A J

    2001-03-01

    Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate the types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.

  18. Fundamental study of droplet spray characteristics in photomask cleaning for advanced lithography

    NASA Astrophysics Data System (ADS)

    Lu, C. L.; Yu, C. H.; Liu, W. H.; Hsu, Luke; Chin, Angus; Lee, S. C.; Yen, Anthony; Lee, Gaston; Dress, Peter; Singh, Sherjang; Dietze, Uwe

    2010-09-01

    The fundamentals of droplet-based cleaning of photomasks are investigated and performance regimes that enable the use of binary spray technologies in advanced mask cleaning are identified. Using phase Doppler anemometry techniques, the effect of key performance parameters such as liquid and gas flow rates and temperature, nozzle design, and surface distance on droplet size, velocity, and distributions were studied. The data are correlated to particle removal efficiency (PRE) and feature damage results obtained on advanced photomasks for 193-nm immersion lithography.

  19. Recent advances in understanding ichthyosis pathogenesis.

    PubMed

    Marukian, Nareh V; Choate, Keith A

    2016-01-01

    The ichthyoses, also known as disorders of keratinization (DOK), encompass a heterogeneous group of skin diseases linked by the common finding of abnormal barrier function, which initiates a default compensatory pathway of hyperproliferation, resulting in the characteristic clinical manifestation of localized and/or generalized scaling. Additional cutaneous findings frequently seen in ichthyoses include generalized xerosis, erythroderma, palmoplantar keratoderma, hypohydrosis, and recurrent infections. In 2009, the Ichthyosis Consensus Conference established a classification consensus for DOK based on pathophysiology, clinical manifestations, and mode of inheritance. This nomenclature system divides DOK into two main groups: nonsyndromic forms, with clinical findings limited to the skin, and syndromic forms, with involvement of additional organ systems. Advances in next-generation sequencing technology have allowed for more rapid and cost-effective genetic analysis, leading to the identification of novel, rare mutations that cause DOK, many of which represent phenotypic expansion. This review focuses on new findings in syndromic and nonsyndromic ichthyoses, with emphasis on novel genetic discoveries that provide insight into disease pathogenesis. PMID:27408699

  20. Recent advances in understanding ichthyosis pathogenesis

    PubMed Central

    Marukian, Nareh V.; Choate, Keith A.

    2016-01-01

    The ichthyoses, also known as disorders of keratinization (DOK), encompass a heterogeneous group of skin diseases linked by the common finding of abnormal barrier function, which initiates a default compensatory pathway of hyperproliferation, resulting in the characteristic clinical manifestation of localized and/or generalized scaling. Additional cutaneous findings frequently seen in ichthyoses include generalized xerosis, erythroderma, palmoplantar keratoderma, hypohydrosis, and recurrent infections. In 2009, the Ichthyosis Consensus Conference established a classification consensus for DOK based on pathophysiology, clinical manifestations, and mode of inheritance. This nomenclature system divides DOK into two main groups: nonsyndromic forms, with clinical findings limited to the skin, and syndromic forms, with involvement of additional organ systems. Advances in next-generation sequencing technology have allowed for more rapid and cost-effective genetic analysis, leading to the identification of novel, rare mutations that cause DOK, many of which represent phenotypic expansion. This review focuses on new findings in syndromic and nonsyndromic ichthyoses, with emphasis on novel genetic discoveries that provide insight into disease pathogenesis. PMID:27408699

  1. A Rooftop Radio Observatory: A New Method for Teaching Science Fundamentals to Advanced Undergraduates

    NASA Astrophysics Data System (ADS)

    Frank, C.; Cudaback, D.; Heiles, C.; Treffers, R.; Hancox, C.; Millan, R.; Parthasarathy, R.

    1996-05-01

    This paper reports on an innovative teaching style for the instruction of advanced undergraduates in experimental science fundamentals. Working under the belief that a complete education includes both theoretical work and ``hands-on'' laboratory experience, a radio observatory has been created on top of the U. C. Berkeley Astronomy Department building. Class work with this observatory give students an understanding of: (1) components of a radio telescope system, (2) system operation and trouble-shooting, (3) observation strategies, (4) data collection and reduction, and (5) presentation and visualization of results. Our antenna consists of a two meter tall pyramidal horn optimized to observe the 21 cm atomic hydrogen transition. The receiver consists of a double-heterodyning system with a PC to sample and Fourier transform the signal and generate a power spectrum. System components were constructed by students with guidance from faculty members. Students using this system obtain power spectra representing the Doppler shifted HI line, as a function of galactic coordinate. Students derive results including basic galactic structure and rotation and mass curves. Further technical information is presented in the accompanying poster paper. Close contact between students and equipment is essential for successful comprehension of fundamental concepts. The system is constructed such that most components can be individually examined or assembled on a bench-top in a configuration the student wishes to explore. We believe that systems which perform real astronomy can be duplicated by other universities. The small scale of the antenna as well as the strength of the HI line require a small allocation of resources to implement an observation system. The ``hands-on'' approach compliments theoretical course work, in addition to providing practical experience for students who may not be inclined towards graduate school. Finally, this educational technique is exportable and

  2. Advances in understanding hydration of Portland cement

    SciTech Connect

    Scrivener, Karen L.; Juilland, Patrick; Monteiro, Paulo J.M.

    2015-12-15

    Progress in understanding hydration is summarized. Evidence supports the geochemistry dissolution theory as an explanation for the induction period, in preference to the inhibiting layer theory. The growth of C–S–H is the principal factor controlling the main heat evolution peak. Electron microscopy indicates that C–S–H “needles” grow from the surface of grains. At the peak, the surface is covered, but deceleration cannot be attributed to diffusion control. The shoulder peak comes from renewed reaction of C{sub 3}A after depletion of sulfate in solution, but release of sulfate absorbed on C–S–H means that ettringite continues to form. After several days space becomes the major factor controlling hydration. The use of new analytical technique is improving our knowledge of the action of superplasticizers and leading to the design of molecules for different applications. Atomistic modeling is becoming a topic of increasing interest. Recent publications in this area are reviewed.

  3. Advances in understanding and treating ADHD

    PubMed Central

    2011-01-01

    Attention deficit hyperactivity disorder (ADHD) is a neurocognitive behavioral developmental disorder most commonly seen in childhood and adolescence, which often extends to the adult years. Relative to a decade ago, there has been extensive research into understanding the factors underlying ADHD, leading to far more treatment options available for both adolescents and adults with this disorder. Novel stimulant formulations have made it possible to tailor treatment to the duration of efficacy required by patients, and to help mitigate the potential for abuse, misuse and diversion. Several new non-stimulant options have also emerged in the past few years. Among these, cognitive behavioral interventions have proven popular in the treatment of adult ADHD, especially within the adult population who cannot or will not use medications, along with the many medication-treated patients who continue to show residual disability. PMID:21658285

  4. Advances in Understanding Decadal Climate Variability

    NASA Technical Reports Server (NTRS)

    Busalacchi, Antonio J.

    1999-01-01

    Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL-FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few ship-tracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.

  5. Advances in Understanding Decadal Climate Variability

    NASA Technical Reports Server (NTRS)

    Busalaacchi, Antonio J.

    1998-01-01

    Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL- FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few shiptracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.

  6. Advances in the understanding of conduction disturbances.

    PubMed

    Kulbertus, H E

    1978-09-01

    The interest towards intraventricular conduction defects started some 10 yr after the introduction of the string galvanometer by Einthoven. As early as 1910, it was known that conduction blockade could occur along either branch of the intraventricular conducting pathway. It took some 20 yr to identify properly the electrocardiographic manifestations of right and left bundle branch blocks. A further 30 yr were needed to obtain a sound correlation between these functional disorders and the presence of anatomical lesions. The more recent introduction of the concept of left hemiblocks further improved our understanding of intraventricular conduction defects. The latter concept is based on the hypothesis of the anatomical and functional bifascicularity of the left bundle branch, a hypothesis which cannot be accepted without some reservations. Later developments indicated that left hemiblocks associated with right bundle branch block represent manifestations of bilateral conduction disturbances (incomplete bilateral bundle branch block). Such an association may constitute a forerunner of complete atrioventricular block, or an indicator of the possibility of sudden death. Whether these complications occur frequently or unfrequently in the setting of incomplete bilateral bundle branch block remains an unsettled question. PMID:699953

  7. Fundamental understanding and life prediction of stress corrosion cracking in BWRs and energy systems

    SciTech Connect

    Andresen, P.L.; Ford, F.P.

    1998-03-01

    The objective of this paper is to present an approach for design and lifetime evaluation of environmental cracking based on experimental and fundamental modeling of the underlying processes operative in crack advance. In detailed this approach and its development and quantification for energy (hot water) systems, the requirements for a life prediction methodology will be highlighted and the shortcomings of the existing design and lifetime evaluation codes reviewed. Examples are identified of its use in a variety of cracking systems, such as stainless steels, low alloy steels, nickel base alloys, and irradiation assisted stress corrosion cracking in boiling water reactor (BWR) water, as well as preliminary use for low alloy steel and Alloy 600 in pressurized water reactors (PWRs) and turbine steels in steam turbines. Identification of the common aspects with environmental cracking in other hot water systems provides a secure basis for its extension to related energy systems. 166 refs., 49 figs.

  8. Using Content-Aligned Assessments to Find Gaps in Understanding of Fundamental Concepts for Weather and Climate

    NASA Astrophysics Data System (ADS)

    Wertheim, J.; Deboer, G. E.

    2009-12-01

    Efforts to assess students’ climate literacy so far have focused mainly on evaluating their understanding of advanced ideas about earth’s complex climate system. It is widely accepted that students, their teachers, and most other adults have persistent misconceptions about climate processes (e.g., the hole in the ozone layer is the main cause of global warming) that preclude them having an accurate understanding of more advanced ideas about the climate. Having established that significant gaps in climate literacy exist even at the college level, it is important to identify where the gaps in understanding of concepts fundamental to climate literacy occur. Here we present results from the most comprehensive assessment of middle and high school students’ understanding of the weather and climate topic to date. Students were given 90 multiple-choice assessment items aligned to various fundamental ideas about weather and climate. Students were also asked to justify their answer choices and to explain why each answer choice was either correct or incorrect. The items were administered to 2063 middle school students and 1006 high school students from 76 schools across the country, sampling a wide range of demographic groups. For the entire set of items, the percent correct for middle school students was 39% and for high school students was 47%. With high school students scoring only 8% better than middle school students overall, and middle school students equaling or outperforming high school students on 20% of the items, it is evident that most high school students do not adequately understand the foundational concepts that climate literacy is built upon, knowledge that is needed if they are going to successfully learn more sophisticated concepts in college. The results from this study are used to validate known misconceptions for middle and high school students, identify new misconceptions, and examine previously reported misconceptions that were not supported by

  9. Advanced Science Students' Understandings on Nature of Science in Finland

    ERIC Educational Resources Information Center

    Sormunen, Kari; Köksal, Mustafa Serdar

    2014-01-01

    Majority of NOS studies comprise of determination or assessment studies conducted with ordinary students. In order to gain further understanding on variation in NOS understandings among the students, there should be different research attempts focusing on unconventional students such as academically advanced students. The purpose of this study is…

  10. Exciton Diffusion in Conjugated Polymers: From Fundamental Understanding to Improvement in Photovoltaic Conversion Efficiency.

    PubMed

    Tamai, Yasunari; Ohkita, Hideo; Benten, Hiroaki; Ito, Shinzaburo

    2015-09-01

    Singlet exciton diffusion plays a central role in the photovoltaic conversion in organic photovoltaics (OPVs). Upon light absorption, singlet excitons are promptly generated in organic materials instead of charge carriers because the dielectric constant (εr) is small (∼3-4), which is in sharp contrast to inorganic and perovskite solar cells. In order to convert to charge carriers, excitons need to diffuse into an interface between electron donor and acceptor materials before deactivating to the ground state. Therefore, fundamental understanding of exciton diffusion dynamics is one of the most important issues to further improve OPVs. We highlight recent leading studies in this field and describe several approaches for efficient exciton harvesting at the interface in OPVs. PMID:26269208

  11. Advances in genetics: widening our understanding of prostate cancer

    PubMed Central

    Pine, Angela C.; Fioretti, Flavia F.; Brooke, Greg N.; Bevan, Charlotte L.

    2016-01-01

    Prostate cancer is a leading cause of cancer-related death in Western men. Our understanding of the genetic alterations associated with disease predisposition, development, progression, and therapy response is rapidly improving, at least in part, owing to the development of next-generation sequencing technologies. Large advances have been made in our understanding of the genetics of prostate cancer through the application of whole-exome sequencing, and this review summarises recent advances in this field and discusses how exome sequencing could be used clinically to promote personalised medicine for prostate cancer patients. PMID:27408704

  12. Understanding Irreversible Degradation of Nb3Sn Wires with Fundamental Fracture Mechanics

    SciTech Connect

    Zhai, Yuhu; Calzolaio, Ciro; Senatore, Carmine

    2014-08-01

    Irreversible performance degradation of advanced Nb3Sn superconducting wires subjected to transverse or axial mechanical loading is a critical issue for the design of large-scale fusion and accelerator magnets such as ITER and LHC. Recent SULTAN tests indicate that most cable-in-conduit conductors for ITER coils made of Nb3Sn wires processed by various fabrication techniques show similar performance degradation under cyclic loading. The irreversible degradation due to filament fracture and local strain accumulation in Nb3Sn wires cannot be described by the existing strand scaling law. Fracture mechanic modeling combined with X-ray diffraction imaging of filament micro-crack formation inside the wires under mechanical loading may reveal exciting insights to the wire degradation mechanisms. We apply fundamental fracture mechanics with a singularity approach to study influence of wire filament microstructure of initial void size and distribution to local stress concentration and potential crack propagation. We report impact of the scale and density of the void structure on stress concentration in the composite wire materials for crack initiation. These initial defects result in an irreversible degradation of the critical current beyond certain applied stress. We also discuss options to minimize stress concentration in the design of the material microstructure for enhanced wire performance for future applications.

  13. Subtask 2.13 - Advanced Hybrid Particulate Collector-Fundamental Performance

    SciTech Connect

    Stanley Miller

    2007-07-01

    Under the Power Plant Improvement Initiative Program funded by the U.S. Department of Energy, a full-scale Advanced Hybrid{trademark} filter was installed at the Big Stone Plant, with start-up in October 2002. The Advanced Hybrid{trademark} filter was retrofitted into Fields 2-4 of the old Big Stone electrostatic precipitator (ESP). While many aspects of the operation were satisfactory, pressure drop was higher than expected. To achieve acceptable pressure drop and successfully demonstrate the Advanced Hybrid{trademark} filter technology, the first fields of the ESP were also converted into an Advanced Hybrid{trademark} filter in 2005. However, since start-up in June 2005, the first fields have been inoperable for multiple reasons. The fundamental cause of the dysfunctional performance of the first fields was attributed to spacing and alignment problems, which led to excessive sparking and shutdown of the high-voltage power. In spite of attempts to correct the problems, satisfactory performance of the first fields was never achieved. Because of the uncertainties of how to achieve acceptable performance with a new technology, the Big Stone Plant made the decision to convert the entire Advanced Hybrid{trademark} filter housing into a pulse-jet fabric filter.

  14. Fundamentals and advances in the development of remote welding fabrication systems

    NASA Technical Reports Server (NTRS)

    Agapakis, J. E.; Masubuchi, K.; Von Alt, C.

    1986-01-01

    Operational and man-machine issues for welding underwater, in outer space, and at other remote sites are investigated, and recent process developments are described. Probable remote welding missions are classified, and the essential characteristics of fundamental remote welding tasks are analyzed. Various possible operational modes for remote welding fabrication are identified, and appropriate roles for humans and machines are suggested. Human operator performance in remote welding fabrication tasks is discussed, and recent advances in the development of remote welding systems are described, including packaged welding systems, stud welding systems, remotely operated welding systems, and vision-aided remote robotic welding and autonomous welding systems.

  15. Towards a fundamental understanding of inhomogeneous interfaces utilizing ballistic electron emission microscopy

    NASA Astrophysics Data System (ADS)

    Balsano, Robert

    A fundamental understanding of charge transport across metal/semiconductor interfaces is of great technological and scientific importance. Metal/semiconductor, or Schottky barrier devices are widely utilized in sensing applications and power electronics. Additionally, Schottky barriers appear in resistive memory technology and current transistor technology. Although Schottky interfaces are ubiquitous, the effects of spatially variant interfaces on the measured Schottky barrier height (SBH) are not entirely understood. For these reasons it is necessary to explore the spatial variation at Schottky interfaces at the nanoscale. Ballistic electron emission microscopy (BEEM) is a three terminal scanning tunneling microscopy (STM) technique used to measure hot carrier transport through materials and across interfaces. BEEM has been used to directly measure the SBH with nanoscale spatial resolution, displaying the natural SBH inhomogeneity. This work explores the utility of SBH mapping with BEEM in identifying interface composition with electrostatic measurements. In the context of the band gap of the semiconductor, a self-consistent test of SBH measurement is presented for Cu/Si(001), Ag/Si(001), and Au/Si(001) diodes. This was accomplished by comparing the sum of the measured SBHs of p-type and n-type samples to the band gap of Si. These measurements are taken at 80 K and verify agreement with the Bell-Kaiser (BK) t to the SBH. Additional 11.7 nm resolution SBH mapping was performed on Au/Ag/Si(001) diodes at 80 K. It was found that the SBH in regions rich in Ag surrounded by Au was raised due to pinch-off effects. Pinch-off is treated in the context of an electrostatic perturbation and is shown to have considerable impact on the samples in this study. By analyzing the statistical distribution of the local SBH, the interface chemical composition is approximated from the relative SBH contribution. The ballistic electron emission microscopy (BEEM) data agreed with

  16. International Workshop on Characterization and PIE Needs for Fundamental Understanding of Fuels Performance and Safety

    SciTech Connect

    Not Listed

    2011-12-01

    The International Workshop on Characterization and PIE Needs to Support Science-Based Development of Innovative Fuels was held June 16-17, 2011, in Paris, France. The Organization for Economic Co-operation and Development (OECD), Nuclear Energy Agency (NEA) Working Party on the Fuel Cycle (WPFC) sponsored the workshop to identify gaps in global capabilities that need to be filled to meet projected needs in the 21st century. First and foremost, the workshop brought nine countries and associated international organizations, together in support of common needs for nuclear fuels and materials testing, characterization, PIE, and modeling capabilities. Finland, France, Germany, Republic of Korea, Russian Federation, Sweden, Switzerland, United Kingdom, United States of America, IAEA, and ITU (on behalf of European Union Joint Research Centers) discussed issues and opportunities for future technical advancements and collaborations. Second, the presentations provided a base level of understanding of current international capabilities. Three main categories were covered: (1) status of facilities and near term plans, (2) PIE needs from fuels engineering and material science perspectives, and (3) novel PIE techniques being developed to meet the needs. The International presentations provided valuable data consistent with the outcome of the National Workshop held in March 2011. Finally, the panel discussion on 21st century PIE capabilities, created a unified approach for future collaborations. In conclusion, (1) existing capabilities are not sufficient to meet the needs of a science-based approach, (2) safety issues and fuels behavior during abnormal conditions will receive more focus post-Fukushima; therefore we need to adopt our techniques to those issues, and (3) International collaboration is needed in the areas of codes and standards development for the new techniques.

  17. Atom-to-continuum methods for gaining a fundamental understanding of fracture.

    SciTech Connect

    McDowell, David Lynn; Reedy, Earl David, Jr.; Templeton, Jeremy Alan; Jones, Reese E.; Moody, Neville Reid; Zimmerman, Jonathan A.; Belytschko, Ted.; Zhou, Xiao Wang; Lloyd, Jeffrey T.; Oswald, Jay; Delph, Terry J.; Kimmer, Christopher J.

    2011-08-01

    This report describes an Engineering Sciences Research Foundation (ESRF) project to characterize and understand fracture processes via molecular dynamics modeling and atom-to-continuum methods. Under this aegis we developed new theory and a number of novel techniques to describe the fracture process at the atomic scale. These developments ranged from a material-frame connection between molecular dynamics and continuum mechanics to an atomic level J integral. Each of the developments build upon each other and culminated in a cohesive zone model derived from atomic information and verified at the continuum scale. This report describes an Engineering Sciences Research Foundation (ESRF) project to characterize and understand fracture processes via molecular dynamics modeling and atom-to-continuum methods. The effort is predicated on the idea that processes and information at the atomic level are missing in engineering scale simulations of fracture, and, moreover, are necessary for these simulations to be predictive. In this project we developed considerable new theory and a number of novel techniques in order to describe the fracture process at the atomic scale. Chapter 2 gives a detailed account of the material-frame connection between molecular dynamics and continuum mechanics we constructed in order to best use atomic information from solid systems. With this framework, in Chapter 3, we were able to make a direct and elegant extension of the classical J down to simulations on the scale of nanometers with a discrete atomic lattice. The technique was applied to cracks and dislocations with equal success and displayed high fidelity with expectations from continuum theory. Then, as a prelude to extension of the atomic J to finite temperatures, we explored the quasi-harmonic models as efficient and accurate surrogates of atomic lattices undergoing thermo-elastic processes (Chapter 4). With this in hand, in Chapter 5 we provide evidence that, by using the appropriate

  18. Fundamental understanding of the synthesis and tribological behavior of organic-inorganic nanoparticles

    NASA Astrophysics Data System (ADS)

    Verma, Arpana

    The objective of this doctoral research is to design, synthesize, and test an advanced lubricant additive using novel active nanostructures of inorganic layered solid lubricant particles (MoS2), integrated and encapsulated with organic molecules, namely triglycerides and phospholipids, respectively. It was hypothesized that this combination can uniquely respond under severe boundary lubrication conditions (where high frictional losses exist). These organic-inorganic nanoparticles were synthesized using a top-down nanomanufacturing process, commonly known as high-energy ball milling or mechanical milling. It was performed in the presence of ambient air followed by organic molecules (triglycerides) to produce nanoparticles with controlled morphologies and surface properties. SEM, particle size analysis, and XRD showed a particle size reduction up to 100 nm and a grain size of 6 nm. TEM showed that after air milling for 48 hrs, agglomerated clusters of quasi-spherical nanoparticles of MoS2 were formed. HRTEM shows that the inter-planar defects and milling assisted shearing between the platelets caused the resultant curling of the planes, forming these unique nanostructures. Further milling of these clusters for 48 hrs in an organic medium (triglycerides) produced mono-dispersed quasi-spherical nanoparticles (<100 nm size). Surface analysis showed the presence of hydrocarbons, COO- molecules on the deagglomerated nanoparticles indicating a chemisorbed capping layer. A capping layer was also confirmed by zeta potential analysis. Tribological studies using pin-on-disk and four-ball tests showed that this novel active material can significantly reduce friction and wear. The coefficient of friction was reduced in pin-on-disk from 0.15 to 0.04 when these nanoparticles were mixed with the base oil. Similarly, in four-ball tests, significant reduction in coefficient of friction (0.06-0.07) and wear (0.47 mm) reduction were observed. To understand the underlying mechanism of

  19. Fundamental Frequency Variation with an Electrolarynx Improves Speech Understanding: A Case Study

    ERIC Educational Resources Information Center

    Watson, Peter J.; Schlauch, Robert S.

    2009-01-01

    Purpose: This study examined the effect of fundamental frequency (F0) variation on the intelligibility of speech in an alaryngeal talker who used an electrolarynx (EL). Method: One experienced alaryngeal talker produced variable F0 and a constant F0 with his EL as he read sentences aloud. As a control, a group of sentences with variable F0 was…

  20. Recent advances in understanding nuclear size and shape.

    PubMed

    Mukherjee, Richik N; Chen, Pan; Levy, Daniel L

    2016-04-25

    Size and shape are important aspects of nuclear structure. While normal cells maintain nuclear size within a defined range, altered nuclear size and shape are associated with a variety of diseases. It is unknown if altered nuclear morphology contributes to pathology, and answering this question requires a better understanding of the mechanisms that control nuclear size and shape. In this review, we discuss recent advances in our understanding of the mechanisms that regulate nuclear morphology, focusing on nucleocytoplasmic transport, nuclear lamins, the endoplasmic reticulum, the cell cycle, and potential links between nuclear size and size regulation of other organelles. We then discuss the functional significance of nuclear morphology in the context of early embryonic development. Looking toward the future, we review new experimental approaches that promise to provide new insights into mechanisms of nuclear size control, in particular microfluidic-based technologies, and discuss how altered nuclear morphology might impact chromatin organization and physiology of diseased cells. PMID:26963026

  1. Advances in graphene-based semiconductor photocatalysts for solar energy conversion: fundamentals and materials engineering.

    PubMed

    Xie, Xiuqiang; Kretschmer, Katja; Wang, Guoxiu

    2015-08-28

    Graphene-based semiconductor photocatalysis has been regarded as a promising technology for solar energy storage and conversion. In this review, we summarized recent developments of graphene-based photocatalysts, including preparation of graphene-based photocatalysts, typical key advances in the understanding of graphene functions for photocatalytic activity enhancement and methodologies to regulate the electron transfer efficiency in graphene-based composite photocatalysts, by which we hope to offer enriched information to harvest the utmost fascinating properties of graphene as a platform to construct efficient graphene-based composite photocatalysts for solar-to-energy conversion. PMID:26204442

  2. Advancing the understanding, monitoring and prediction of North American drought in support of NIDIS

    NASA Astrophysics Data System (ADS)

    Mariotti, Annarita; Pulwarty, Roger

    2014-05-01

    The NOAA's Drought Task Force was established in October 2011 with the goal of achieving significant new advances in the ability to understand, monitor and predict drought over North America. The Task Force is an initiative of NOAA's Climate Program Office Modeling, Analysis, Predictions, and Projections (MAPP) program in support of the National Integrated Drought Information System NIDIS. It brings together over thirty-five leading drought scientists research laboratories and/or operational centers from NOAA, other U.S. agencies laboratories and academia. Their concerted research effort builds on individual MAPP research projects and related drought-research sector developments. The projects span the wide spectrum of drought research needed to make fundamental advances, from those aimed at the basic understanding of drought mechanisms to those evaluating new drought monitoring and prediction tools for operational and service purposes. In this presentation we will show how a coordinated, sustained multidisciplinary effort to assess understanding of both past droughts and emergent events contributes to the effectiveness of early warning systems. This contribution will present an overview of Drought Task Force activities to date, including highlights of research activities and how the group has been working in partnership with NIDIS to advance the science underpinning the development, assessment and provision of drought information.

  3. Advancing Model Systems for Fundamental Laboratory Studies of Sea Spray Aerosol Using the Microbial Loop.

    PubMed

    Lee, Christopher; Sultana, Camille M; Collins, Douglas B; Santander, Mitchell V; Axson, Jessica L; Malfatti, Francesca; Cornwell, Gavin C; Grandquist, Joshua R; Deane, Grant B; Stokes, M Dale; Azam, Farooq; Grassian, Vicki H; Prather, Kimberly A

    2015-08-20

    Sea spray aerosol (SSA) particles represent one of the most abundant surfaces available for heterogeneous reactions to occur upon and thus profoundly alter the composition of the troposphere. In an effort to better understand tropospheric heterogeneous reaction processes, fundamental laboratory studies must be able to accurately reproduce the chemical complexity of SSA. Here we describe a new approach that uses microbial processes to control the composition of seawater and SSA particle composition. By inducing a phytoplankton bloom, we are able to create dynamic ecosystem interactions between marine microorganisms, which serve to alter the organic mixtures present in seawater. Using this controlled approach, changes in seawater composition become reflected in the chemical composition of SSA particles 4 to 10 d after the peak in chlorophyll-a. This approach for producing and varying the chemical complexity of a dominant tropospheric aerosol provides the foundation for further investigations of the physical and chemical properties of realistic SSA particles under controlled conditions. PMID:26196268

  4. Understanding the fundamental electrical and photoelectrochemical behavior of a hematite photoanode.

    PubMed

    Soares, Mario R S; Gonçalves, Ricardo H; Nogueira, Içamira C; Bettini, Jefferson; Chiquito, Adenilson J; Leite, Edson R

    2016-08-01

    Hematite is considered to be the most promising material used as a photoanode for water splitting and here we utilized a sintered hematite photoanode to address the fundamental electrical, electrochemical and photoelectrochemical behavior of this semiconductor oxide. The results presented here allowed us to conclude that the addition of Sn(4+) decreases the grain boundary resistance of the hematite polycrystalline electrode. Heat treatment in a nitrogen (N2) atmosphere also contributes to a decrease of the grain boundary resistance, supporting the evidence that the presence of oxygen is fundamental for the formation of a voltage barrier at the hematite grain boundary. The N2 atmosphere affected both doped and undoped sintered electrodes. We also observed that the heat treatment atmosphere modifies the surface states of the solid-liquid interface, changing the charge-transfer resistance. A two-step treatment, with the second being performed at a low temperature in an oxygen (O2) atmosphere, resulted in a better solid-liquid interface. PMID:27436162

  5. Advancing our understanding of the human microbiome using QIIME

    PubMed Central

    Navas-Molina, José A.; Peralta-Sánchez, Juan M.; González, Antonio; McMurdie, Paul J.; Vázquez-Baeza, Yoshiki; Xu, Zhenjiang; Ursell, Luke K.; Lauber, Christian; Zhou, Hongwei; Song, Se Jin; Huntley, James; Ackermann, Gail L.; Berg-Lyons, Donna; Holmes, Susan; Caporaso, J. Gregory; Knight, Rob

    2014-01-01

    High-throughput DNA sequencing technologies, coupled with advanced bioinformatics tools, have enabled rapid advances in microbial ecology and our understanding of the human microbiome. QIIME (Quantitative Insights Into Microbial Ecology) is an open-source bioinformatics software package designed for microbial community analysis based on DNA sequence data, which provides a single analysis framework for analysis of raw sequence data through publication quality statistical analyses and interactive visualizations. In this paper, we demonstrate the use of the QIIME pipeline to analyze microbial communities obtained from several sites on the bodies of transgenic and wild-type mice, as assessed using 16S rRNA gene sequences generated on the Illumina MiSeq platform. We present our recommended pipeline for performing microbial community analysis, and provide guidelines for making critical choices in the process. We present examples of some of the types of analyses that are enabled by QIIME, and discuss how other tools, such as phyloseq and R, can be applied to expand upon these analyses. PMID:24060131

  6. Recent advances in understanding Antarctic subglacial lakes and hydrology.

    PubMed

    Siegert, Martin J; Ross, Neil; Le Brocq, Anne M

    2016-01-28

    It is now well documented that over 400 subglacial lakes exist across the bed of the Antarctic Ice Sheet. They comprise a variety of sizes and volumes (from the approx. 250 km long Lake Vostok to bodies of water less than 1 km in length), relate to a number of discrete topographic settings (from those contained within valleys to lakes that reside in broad flat terrain) and exhibit a range of dynamic behaviours (from 'active' lakes that periodically outburst some or all of their water to those isolated hydrologically for millions of years). Here we critique recent advances in our understanding of subglacial lakes, in particular since the last inventory in 2012. We show that within 3 years our knowledge of the hydrological processes at the ice-sheet base has advanced considerably. We describe evidence for further 'active' subglacial lakes, based on satellite observation of ice-surface changes, and discuss why detection of many 'active' lakes is not resolved in traditional radio-echo sounding methods. We go on to review evidence for large-scale subglacial water flow in Antarctica, including the discovery of ancient channels developed by former hydrological processes. We end by predicting areas where future discoveries may be possible, including the detection, measurement and significance of groundwater (i.e. water held beneath the ice-bed interface). PMID:26667914

  7. Recent advances in understanding Antarctic subglacial lakes and hydrology

    PubMed Central

    Siegert, Martin J.; Ross, Neil; Le Brocq, Anne M.

    2016-01-01

    It is now well documented that over 400 subglacial lakes exist across the bed of the Antarctic Ice Sheet. They comprise a variety of sizes and volumes (from the approx. 250 km long Lake Vostok to bodies of water less than 1 km in length), relate to a number of discrete topographic settings (from those contained within valleys to lakes that reside in broad flat terrain) and exhibit a range of dynamic behaviours (from ‘active’ lakes that periodically outburst some or all of their water to those isolated hydrologically for millions of years). Here we critique recent advances in our understanding of subglacial lakes, in particular since the last inventory in 2012. We show that within 3 years our knowledge of the hydrological processes at the ice-sheet base has advanced considerably. We describe evidence for further ‘active’ subglacial lakes, based on satellite observation of ice-surface changes, and discuss why detection of many ‘active’ lakes is not resolved in traditional radio-echo sounding methods. We go on to review evidence for large-scale subglacial water flow in Antarctica, including the discovery of ancient channels developed by former hydrological processes. We end by predicting areas where future discoveries may be possible, including the detection, measurement and significance of groundwater (i.e. water held beneath the ice-bed interface). PMID:26667914

  8. Fundamental research on spiking, recovery and understanding seed coat nep counts in AFIS analysis of pre-opened cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding seed coat fragment (SCF) spiking results in Advanced Fiber Information Systems (AFIS) analysis of seed coat neps (SCN) in ginned cottons was confounded by side processes in the system such as particle crushing that results in inflated recoveries. A high degree of machine (AFIS)-fiber ...

  9. Teaching Statistical Thinking: Providing a Fundamental Way of Understanding the World.

    ERIC Educational Resources Information Center

    Kugler, Charles; Hagen, Joel; Singer, Fred

    2003-01-01

    Describes the importance of statistical reasoning in understanding modern science and critically evaluating information. Uses spreadsheet programs and the black box approach to teach basic concepts of statistical reasoning. Presents examples of the role of statistical thinking in the disciplines of biology, chemistry, physics, and geology.…

  10. Recent advances in understanding transcription termination by RNA polymerase II

    PubMed Central

    Loya, Travis J.; Reines, Daniel

    2016-01-01

    Transcription termination is a fundamental process in which RNA polymerase ceases RNA chain extension and dissociates from the chromatin template, thereby defining the end of the transcription unit. Our understanding of the biological role and functional importance of termination by RNA polymerase II and the range of processes in which it is involved has grown significantly in recent years. A large set of nucleic acid-binding proteins and enzymes have been identified as part of the termination machinery. A greater appreciation for the coupling of termination to RNA processing and metabolism has been recognized. In addition to serving as an essential step at the end of the transcription cycle, termination is involved in the regulation of a broad range of cellular processes. More recently, a role for termination in pervasive transcription, non-coding RNA regulation, genetic stability, chromatin remodeling, the immune response, and disease has come to the fore. Interesting mechanistic questions remain, but the last several years have resulted in significant insights into termination and an increasing recognition of its biological importance. PMID:27408690

  11. NOAA Drought Task Force: A Coordinated Research Initiative to Advance Drought Understanding, Monitoring and Prediction

    NASA Astrophysics Data System (ADS)

    Mariotti, A.; Barrie, D.

    2014-12-01

    The NOAA's Drought Task Force was first established in October 2011 and renewed in October 2014 with the goal of achieving significant new advances in the ability to understand, monitor and predict drought over North America. The Task Force is an initiative of NOAA's Climate Program Office Modeling, Analysis, Predictions, and Projections (MAPP) program in support of the National Integrated Drought Information System NIDIS. The Drought Task Force also represents an important research contribution to efforts to develop an international Global Drought Information System (GDIS). The Drought Task Force brings together leading drought scientists research laboratories and/or operational centers from NOAA, other U.S. agencies laboratories and academia. Their concerted research effort builds on individual MAPP research projects and related drought-research sector developments. The projects span the wide spectrum of drought research needed to make fundamental advances, from those aimed at the basic understanding of drought mechanisms to those evaluating new drought monitoring and prediction tools for operational and service purposes. This contribution will present an overview of Drought Task Force activities and plans to date, including highlights of research activities and how the group has been working in partnership with NIDIS and synergy with GDIS to advance the science underpinning the development, assessment and provision of drought information.

  12. Advances in understanding the urine-concentrating mechanism.

    PubMed

    Sands, Jeff M; Layton, Harold E

    2014-01-01

    The renal medulla produces concentrated urine through the generation of an osmotic gradient that progressively increases from the cortico-medullary boundary to the inner medullary tip. In the outer medulla, the osmolality gradient arises principally from vigorous active transport of NaCl, without accompanying water, from the thick ascending limbs of short- and long-looped nephrons. In the inner medulla, the source of the osmotic gradient has not been identified. Recently, there have been important advances in our understanding of key components of the urine-concentrating mechanism, including (a) better understanding of the regulation of water, urea, and sodium transport proteins; (b) better resolution of the anatomical relationships in the medulla; and (c) improvements in mathematical modeling of the urine-concentrating mechanism. Continued experimental investigation of signaling pathways regulating transepithelial transport, both in normal animals and in knockout mice, and incorporation of the resulting information into mathematical simulations may help to more fully elucidate the mechanism for concentrating urine in the inner medulla. PMID:24245944

  13. A mechanistic approach to understanding oral drug absorption in pediatrics: an overview of fundamentals.

    PubMed

    Debotton, Nir; Dahan, Arik

    2014-09-01

    The common phrase 'children are not little adults' is very true also in the field of oral drug administration and absorption. However, in practice, due to the little available data and lack of in-depth understanding, physicians may treat kids as if they were 'little adults', even without being aware of the potential differences and risks. With respect to drug discovery, research and development, an in-depth understanding of the various factors governing age-dependent absorption is crucial when trying to develop a pediatric-tailored oral drug product. In this paper we clarify the various mechanisms that may lead to age-dependent oral drug absorption, we provide an overview of the currently available data, and draw conclusions to the coming years. PMID:24846709

  14. A unifying approach to understanding transitional waters: Fundamental properties emerging from ecotone ecosystems

    NASA Astrophysics Data System (ADS)

    Basset, Alberto; Barbone, Enrico; Elliott, Michael; Li, Bai-Lian; Jorgensen, Sven Eric; Lucena-Moya, Paloma; Pardo, Isabel; Mouillot, David

    2013-11-01

    Estuaries, rias, fjords and lagoons (collectively called transitional waters, TW) are highly important ecosystems both for their high productivity but also as sites of urban and industrial development, supporting many major cities and ports. Increasingly they are accepted as transitional environments and in Europe this term has been given legal and management importance; indeed, in some cases this has led to decisions with high economic repercussions. We have thus revisited the fundamental properties and paradigms of these systems in the light of recent ecological theory. The analysis has produced a unifying approach to transitional waters, by adopting and expanding the concept of ecotone to whole ecosystems, rather than ecosystem boundaries. Furthermore we have addressed the paradoxes related to (1) the gradients concerning variability and stability in the system, (2) the biodiversity and ecosystem functioning, as well as (3) the response and resilience of the system to anthropogenic stressors. We conclude that the term Transitional Waters is not merely a legal convenience or that the TW are merely an interface, with positive and negative characteristics, but ecological systems in their own right.

  15. Fundamental Challenges in Mechanistic Enzymology: Progress toward Understanding the Rate Enhancements of Enzymes

    PubMed Central

    Herschlag, Daniel; Natarajan, Aditya

    2013-01-01

    Enzymes are remarkable catalysts that lie at the heart of biology, accelerating chemical reactions to an astounding extent with extraordinary specificity. Enormous progress in understanding the chemical basis of enzymatic transformations and the basic mechanisms underlying rate enhancements over the past decades is apparent. Nevertheless, it has been difficult to achieve a quantitative understanding of how the underlying mechanisms account for the energetics of catalysis, because of the complexity of enzyme systems and the absence of underlying energetic additivity. We review case studies from our own work that illustrate the power of precisely defined and clearly articulated questions when dealing with such complex and multi-faceted systems, and we also use this approach to evaluate our current ability to design enzymes. We close by highlighting a series of questions that help frame some of what remains to be understood, and we encourage the reader to define additional questions and directions that will deepen and broaden our understanding of enzymes and their catalysis. PMID:23488725

  16. Developing high-performance cross-functional teams: Understanding motivations, functional loyalties, and teaming fundamentals

    SciTech Connect

    Miller, M.A.

    1996-08-01

    Teamwork is the key to the future of effective technology management. Today`s technologies and markets have become too complex for individuals to work alone. Global competition, limited resources, cost consciousness, and time pressures have forced organizations and project managers to encourage teamwork. Many of these teams will be cross-functional teams that can draw on a multitude of talents and knowledge. To develop high-performing cross-functional teams, managers must understand motivations, functional loyalties, and the different backgrounds of the individual team members. To develop a better understanding of these issues, managers can learn from experience and from literature on teams and teaming concepts. When studying the literature to learn about cross-functional teaming, managers will find many good theoretical concepts, but when put into practice, these concepts have varying effects. This issue of varying effectiveness is what drives the research for this paper. The teaming concepts were studied to confirm or modify current understanding. The literature was compared with a {open_quotes}ground truth{close_quotes}, a survey of the reality of teaming practices, to examine the teaming concepts that the literature finds to be critical to the success of teams. These results are compared to existing teams to determine if such techniques apply in real-world cases.

  17. Towards a Fundamental Understanding of Short Period Eclipsing Binary Systems Using Kepler Data

    NASA Astrophysics Data System (ADS)

    Prsa, Andrej

    Kepler's ultra-high precision photometry is revolutionizing stellar astrophysics. We are seeing intrinsic phenomena on an unprecedented scale, and interpreting them is both a challenge and an exciting privilege. Eclipsing binary stars are of particular significance for stellar astrophysics because precise modeling leads to fundamental parameters of the orbiting components: masses, radii, temperatures and luminosities to better than 1-2%. On top of that, eclipsing binaries are ideal physical laboratories for studying other physical phenomena, such as asteroseismic properties, chromospheric activity, proximity effects, mass transfer in close binaries, etc. Because of the eclipses, the basic geometry is well constrained, but a follow-up spectroscopy is required to get the dynamical masses and the absolute scale of the system. A conjunction of Kepler photometry and ground- based spectroscopy is a treasure trove for eclipsing binary star astrophysics. This proposal focuses on a carefully selected set of 100 short period eclipsing binary stars. The fundamental goal of the project is to study the intrinsic astrophysical effects typical of short period binaries in great detail, utilizing Kepler photometry and follow-up spectroscopy to devise a robust and consistent set of modeling results. The complementing spectroscopy is being secured from 3 approved and fully funded programs: the NOAO 4-m echelle spectroscopy at Kitt Peak (30 nights; PI Prsa), the 10- m Hobby-Eberly Telescope high-resolution spectroscopy (PI Mahadevan), and the 2.5-m Sloan Digital Sky Survey III spectroscopy (PI Mahadevan). The targets are prioritized by the projected scientific yield. Short period detached binaries host low-mass (K- and M- type) components for which the mass-radius relationship is sparsely populated and still poorly understood, as the radii appear up to 20% larger than predicted by the population models. We demonstrate the spectroscopic detection viability in the secondary

  18. Recent advances in the understanding and management of delayed puberty.

    PubMed

    Wei, Christina; Crowne, Elizabeth Clare

    2016-05-01

    Delayed puberty, especially in boys, is a common presentation in paediatrics. Recent advances have improved our understanding of the neuroendocrine, genetic and environmental factors controlling pubertal development, and hence inform the pathophysiology of delayed puberty. The discovery of kisspeptin signalling through its receptor identified neuroendocrine mechanisms controlling the gonadotrophin-releasing hormone (GnRH) pulse generator at the onset of puberty. Genetic mechanisms from single gene mutations to single nucleotide polymorphism associated with delayed puberty are being identified. Environmental factors, including nutritional factors and endocrine disruptors, have also been implicated in changes in secular trends and abnormal timing of puberty. Despite these advances, the key clinical question is to distinguish delayed puberty associated with an underlying pathology or hypogonadism from constitutional delay in growth and puberty, which remains challenging as biochemical tests are not always discriminatory. The diagnostic accuracies of newer investigations, including 36-hour luteinising hormone releasing hormone (LHRH) tests, GnRH-agonist tests, antimullerian hormone and inhibin-B, require further evaluation. Sex hormone replacement remains the main available treatment for delayed puberty, the choice of which is largely dictated by clinical practice and availability of the various sex steroid preparations. Spontaneous reversal of hypogonadism has been reported in boys with idiopathic hypogonadotrophic hypogonadism after a period of sex steroid treatment, highlighting the importance of reassessment at the end of pubertal induction. Novel therapies with a more physiological basis such as gonadotrophins or kisspeptin-agonist are being investigated for the management of hypogonadotrophic hypogonadism. Careful clinical assessment and appreciation of the normal physiology remain the key approach to patients with delayed puberty. PMID:26353794

  19. Dosimetric validation of the Acuros XB Advanced Dose Calculation algorithm: fundamental characterization in water

    NASA Astrophysics Data System (ADS)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Mancosu, Pietro; Cozzi, Luca

    2011-03-01

    A new algorithm, Acuros® XB Advanced Dose Calculation, has been introduced by Varian Medical Systems in the Eclipse planning system for photon dose calculation in external radiotherapy. Acuros XB is based on the solution of the linear Boltzmann transport equation (LBTE). The LBTE describes the macroscopic behaviour of radiation particles as they travel through and interact with matter. The implementation of Acuros XB in Eclipse has not been assessed; therefore, it is necessary to perform these pre-clinical validation tests to determine its accuracy. This paper summarizes the results of comparisons of Acuros XB calculations against measurements and calculations performed with a previously validated dose calculation algorithm, the Anisotropic Analytical Algorithm (AAA). The tasks addressed in this paper are limited to the fundamental characterization of Acuros XB in water for simple geometries. Validation was carried out for four different beams: 6 and 15 MV beams from a Varian Clinac 2100 iX, and 6 and 10 MV 'flattening filter free' (FFF) beams from a TrueBeam linear accelerator. The TrueBeam FFF are new beams recently introduced in clinical practice on general purpose linear accelerators and have not been previously reported on. Results indicate that Acuros XB accurately reproduces measured and calculated (with AAA) data and only small deviations were observed for all the investigated quantities. In general, the overall degree of accuracy for Acuros XB in simple geometries can be stated to be within 1% for open beams and within 2% for mechanical wedges. The basic validation of the Acuros XB algorithm was therefore considered satisfactory for both conventional photon beams as well as for FFF beams of new generation linacs such as the Varian TrueBeam.

  20. New genetic findings lead the way to a better understanding of fundamental mechanisms of drug hypersensitivity.

    PubMed

    Pirmohamed, Munir; Ostrov, David A; Park, B Kevin

    2015-08-01

    Drug hypersensitivity reactions are an important clinical problem for both health care and industry. Recent advances in genetics have identified a number of HLA alleles associated with a range of these adverse reactions predominantly affecting the skin but also other organs, such as the liver. The associations between abacavir hypersensitivity and HLA-B*57:01 and carbamazepine-induced Stevens-Johnson syndrome and HLA-B*15:02 have been implemented in clinical practice. There are many different mechanisms proposed in the pathogenesis of drug hypersensitivity reactions, including the hapten hypothesis, direct binding to T-cell receptors (the pharmacologic interaction hypothesis), and peptide-binding displacement. A problem with all the hypotheses is that they are largely based on in vitro findings, with little direct in vivo evidence. Although most studies have focused on individual mechanisms, it is perhaps more important to consider them all as being complementary, potentially occurring at the same time with the same drug in the same patient. This might at least partly account for the heterogeneity of the immune response seen in different patients. There is a need to develop novel methodologies to evaluate how the in vitro mechanisms relate to the in vivo situation and how the highly consistent genetic findings with different HLA alleles can be more consistently used for both prediction and prevention of these serious adverse reactions. PMID:26254050

  1. New genetic findings lead the way to a better understanding of fundamental mechanisms of drug hypersensitivity

    PubMed Central

    Pirmohamed, Munir; Ostrov, David A.; Park, B. Kevin

    2015-01-01

    Drug hypersensitivity reactions are an important clinical problem for both health care and industry. Recent advances in genetics have identified a number of HLA alleles associated with a range of these adverse reactions predominantly affecting the skin but also other organs, such as the liver. The associations between abacavir hypersensitivity and HLA-B*57:01 and carbamazepine-induced Stevens-Johnson syndrome and HLA-B*15:02 have been implemented in clinical practice. There are many different mechanisms proposed in the pathogenesis of drug hypersensitivity reactions, including the hapten hypothesis, direct binding to T-cell receptors (the pharmacologic interaction hypothesis), and peptide-binding displacement. A problem with all the hypotheses is that they are largely based on in vitro findings, with little direct in vivo evidence. Although most studies have focused on individual mechanisms, it is perhaps more important to consider them all as being complementary, potentially occurring at the same time with the same drug in the same patient. This might at least partly account for the heterogeneity of the immune response seen in different patients. There is a need to develop novel methodologies to evaluate how the in vitro mechanisms relate to the in vivo situation and how the highly consistent genetic findings with different HLA alleles can be more consistently used for both prediction and prevention of these serious adverse reactions. PMID:26254050

  2. Recent advances in understanding and diagnosing hepatitis B virus infection

    PubMed Central

    Fourati, Slim; Pawlotsky, Jean-Michel

    2016-01-01

    Hepatitis B virus (HBV) infects approximately 240 million individuals worldwide. Recent advances in the virology, immunopathogenesis, and diagnosis of HBV infection are summarized in this review article. The identification of a hepatocyte-specific cellular receptor for HBV, the sodium taurocholate co-transporting polypeptide (NTCP), made it possible to develop reliable cell culture systems and better understand the early steps of the viral lifecycle. Viral and host factors involved in covalently closed circular DNA synthesis, stability, and transcriptional regulation have also been identified and provide potential targets for new drugs. Based on recent evidence showing trained immunity in immune-tolerant patients, the immune tolerance and immune clearance phases have been renamed the non-inflammatory and inflammatory phases, respectively. New diagnostic and monitoring tools are now available, including rapid diagnostic tests for hepatitis B surface antigen (HBsAg) detection, HBsAg quantification assays, anti-HBc antibody quantification assays, an HBV core-related antigen (HBcrAg) quantification test, new HBV DNA detection and quantification assays, and an HBV RNA quantification test. Their clinical utility is under study. Finally, new antiviral and immune modulation approaches are in the preclinical or early clinical developmental stages, with the goal to achieve functional cure or ideally (if possible) eradication of HBV infection.

  3. Recent Advances in Understanding Enteric Pathogenic Escherichia coli

    PubMed Central

    Croxen, Matthew A.; Law, Robyn J.; Scholz, Roland; Keeney, Kristie M.; Wlodarska, Marta

    2013-01-01

    SUMMARY Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli. PMID:24092857

  4. Fundamental understanding of wave generation and reception using d(36) type piezoelectric transducers.

    PubMed

    Zhou, Wensong; Li, Hui; Yuan, Fuh-Gwo

    2015-03-01

    A new piezoelectric wafer made from a PMN-PT single crystal with dominant piezoelectric coefficient d36 is proposed to generate and detect guided waves on isotropic plates. The in-plane shear coupled with electric field arising from the piezoelectric coefficient is not usually present for conventional piezoelectric wafers, such as lead zirconate titanate (PZT). The direct piezoelectric effect of coefficient d36 indicates that under external in-plane shear stress the charge is induced on a face perpendicular to the poled z-direction. On thin plates, this type of piezoelectric wafer will generate shear horizontal (SH) waves in two orthogonal wave propagation directions as well as two Lamb wave modes in other wave propagation directions. Finite element analyses are employed to explore the wave disturbance in terms of time-varying displacements excited by the d36 wafer in different directions of wave propagation to understand all the guided wave modes accurately. Experiments are conducted to examine the voltage responses received by this type of wafer, and also investigate results of tuning frequency and effects of d31 piezoelectric coefficient, which is intentionally ignored in the finite element analysis. All results demonstrate the main features and utility of proposed d36 piezoelectric wafer for guided wave generation and detection in structural health monitoring. PMID:25465107

  5. Nanoparticles Stabilize Thin Polymer Films: A Fundamental Study to Understand the Phenomenon

    SciTech Connect

    Michael E. Mackay

    2009-03-04

    A new understanding of thermodynamics at the nanoscale resulted in a recently discovered first order phase transition that nanoparticles in a polymer film will all segregate to the supporting substrate. This is an unusual phase transition that was predicted using a modeling technique developed at Sandia National Laboratories and required the equivalent of many computational years on one computer. This project is a collaboration between Prof. Michael Mackay's group and Dr. Amalie Frischknecht (Sandia National Laboratories) where experimental observation and theoretical rationalization and prediction are brought together. Other discoveries were that this phase transition could be avoided by changing the nanoparticle properties yielding control of the assembly process at the nanoscale. In fact, the nanoparticles could be made to assemble to the supporting substrate, to the air interface or not assemble at all within a thin polymer film of order 100 nm in thickness. However, when the assembly process is present it is so robust that it is possible to make rough liquid films at the nanoscale due to nanoparticles assembling around three-dimensional objects. From this knowledge we are able to design and manufacture new coatings with particular emphasis on polymer-based solar cells. Careful control of the morphology at the nanoscale is expected to provide more efficient devices since the physics of these systems is dictated at this length scale and assembly of nanoparticles to various interfaces is critical to operation.

  6. Development of a Fundamental Understanding of Chemical Bonding and Electronic Structure in Spinel Compounds

    SciTech Connect

    Sickafus, K.E.; Wills, J.M.; Chen, S.-P.; Terry, J.H., Jr.; Hartmann, T.; Sheldon, R.I.

    1999-05-14

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos national Laboratory (LANL). Hundreds of ceramic compounds possess the spinel crystal structure and exhibit a remarkable variety of properties, ranging from compounds that are electrical insulators to compounds that are superconducting, or from compounds with ferri- and antiferromagnetic behavior to materials with colossal magnetoresistive characteristics. The unique crystal structure of spinel compounds is in many ways responsible for the widely varying physical properties of spinels. The objective of this project is to investigate the nature of chemical bonding, point defects, and electronic structure in compounds with the spinel crystal structure. Our goal is to understand and predict the stability of the spinel structure as a function of chemical composition, stoichiometry, and cation disorder. The consequences of cation disorder in spinel materials can be profound . The ferromagnetic characteristics of magnesioferrite, for instance, are entirely attributable to disorder on the cation sublattices. Our studies provide insight into the mechanisms of point defect formation and cation disorder and their effects on the electronic band structure and crystal structure of spinel-structure materials. our ultimate objective is to develop a more substantive knowledge of the spinel crystal structure and to promote new and novel uses for spinel compounds. The technical approach to achieve our goals is to combine first-principles calculations with experimental measurements. The structural and electronic properties of spinel samples were experimentally determined primarily with X-ray and neutron scattering, optical and X-ray absorption, and electron energy-loss spectroscopy. Total energy electronic structure calculations were performed to determine structural stability, band structure, density of states, and electron distribution. We also used shell

  7. Development of a Fundamental Understanding of Chemical Bonding and Electronic Structure in Spinel Compounds

    SciTech Connect

    Sickafus, K.E.; Wills, J.M.; Chen, S.-P.; Terry, J.H., Jr.; Hartmann, T.; Sheldon, R.I.

    1999-06-03

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Hundreds of ceramic compounds possess the spinel crystal structure and exhibit a remarkable variety of properties, ranging from compounds that are electrical insulators to compounds that are superconducting, or from compounds with ferri- and antiferromagnetic behavior to materials with colossal magnetoresistive characteristics. The unique crystal structure of spinel compounds is in many ways responsible for the widely varying physical properties of spinels. The objective of this project is to investigate the nature of chemical bonding, point defects, and electronic structure in compounds with the spinel crystal structure. Our goal is to understand and predict the stability of the spinel structure as a function of chemical composition, stoichiometry, and cation disorder. The consequences of cation disorder in spinel materials can be profound . The ferromagnetic characteristics of magnesioferrite, for instance, are entirely attributable to disorder on the cation sublattices. Our studies provide insight into the mechanisms of point defect formation and cation disorder and their effects on the electronic band structure and crystal structure of spinel-structure materials. Our ultimate objective is to develop a more substantive knowledge of the spinel crystal structure and to promote new and novel uses for spinel compounds. The technical approach to achieve our goals is to combine first-principles calculations with experimental measurements. The structural and electronic properties of spinel samples were experimentally determined primarily with X-ray and neutron scattering, optical and X-ray absorption, and electron energy-loss spectroscopy. Total energy electronic structure calculations were performed to determine structural stability, band structure, density of states, and electron distribution. We also used shell

  8. Fundamental understanding of the growth, doping and characterization of aligned ZnO nanowires

    NASA Astrophysics Data System (ADS)

    Shen, Gang

    . Possible Al incorporation related peaks were observed in the mass spectrum of Al doped ZnO NWs. Further work on Al doped ZnO LEAP analysis is needed to better understand the Al dopant.

  9. Advances in the understanding and operations of superconducting colliders

    SciTech Connect

    Annala, G.; Bauer, P.; Bottura, L.; Martens, M.A.; Sammut, N.; Velev, G.; Shiltsev, V.; /Fermilab

    2005-05-01

    Chromaticity drift during injection is a well-known phenomenon in superconducting colliders, such as the Tevatron, HERA and RHIC. Imperfect compensation of the drift effects can contribute to beam loss and emittance growth. It is caused by the drift of the sextupole component in the dipole magnets due to current redistribution in its superconducting coils. Recently extensive studies of chromaticity drift were conducted at the Tevatron, aiming at the improvement of the luminosity performance in the ongoing run II. These studies included not only beam experiments, but also extensive off-line magnetic measurements on spare Tevatron dipoles. Less known, until recently, is that chromaticity drift is often accompanied by tune and coupling drift. This was recently discovered in the Tevatron. We believe that these effects are the product of systematic beam offset in conjunction with the sextupole drifts (and their compensation in the chromaticity correctors). These discoveries are most relevant to the upcoming LHC, where the drift effects will have even more dramatic consequences given the high beam current. It is therefore not a surprise that CERN has been the source of major advances in the understanding of dynamic effects during the LHC superconducting magnet development. The following will briefly review the CERN results as well as those of the recent Fermilab studies. A new result, which will be presented here also, is related to fast drifts occurring in the first few seconds of the injection plateau. Again, these fast drifts were observed first in the Tevatron and efforts are underway to explain them. Finally this paper will attempt to derive the implications of these drift effects on LHC commissioning and operation.

  10. Fundamental Understanding of Ambient and High-Temperature Plasticity Phenomena in Structural Materials in Advanced Reactors

    SciTech Connect

    Deo, Chaitanya; Zhu, Ting; McDowell, David

    2013-11-17

    The goal of this research project is to develop the methods and tools necessary to link unit processes analyzed using atomistic simulations involving interaction of vacancies and interstitials with dislocations, as well as dislocation mediation at sessile junctions and interfaces as affected by radiation, with cooperative influence on higher-length scale behavior of polycrystals. These tools and methods are necessary to design and enhance radiation-induced damage-tolerant alloys. The project will achieve this goal by applying atomistic simulations to characterize unit processes of: 1. Dislocation nucleation, absorption, and desorption at interfaces 2. Vacancy production, radiation-induced segregation of substitutional Cr at defect clusters (point defect sinks) in BCC Fe-Cr ferritic/martensitic steels 3. Investigation of interaction of interstitials and vacancies with impurities (V, Nb, Ta, Mo, W, Al, Si, P, S) 4. Time evolution of swelling (cluster growth) phenomena of irradiated materials 5. Energetics and kinetics of dislocation bypass of defects formed by interstitial clustering and formation of prismatic loops, informing statistical models of continuum character with regard to processes of dislocation glide, vacancy agglomeration and swelling, climb and cross slip This project will consider the Fe, Fe-C, and Fe-Cr ferritic/martensitic material system, accounting for magnetism by choosing appropriate interatomic potentials and validating with first principles calculations. For these alloys, the rate of swelling and creep enhancement is considerably lower than that of face-centered cubic (FCC) alloys and of austenitic Fe-Cr-Mo alloys. The team will confirm mechanisms, validate simulations at various time and length scales, and improve the veracity of computational models. The proposed research?s feasibility is supported by recent modeling of radiation effects in metals and alloys, interfacial dislocation transfer reactions in nano-twinned copper, and dislocation reactions at general boundaries, along with extensive modeling cooperative effects of dislocation interactions and migration in crystals and polycrystals using continuum models.

  11. Advancing the Fundamental Understanding of Fission: 2014 LDRD 20120077DR Review

    SciTech Connect

    White, Morgan C.; Tovesson, Fredrik K.; Sierk, Arnold John

    2014-02-06

    The following slides were presented as part of the LDRD 20120077DR Progress Appraisal Review held Tuesday, February 4, 2014. This is part of an ongoing project assessment the previous of which was documented in LA-UR-13-21182. This presentation documents the progress made against the goals agreed to as part of the 2013 review.

  12. Some recent advances in understanding the mineralogy of Earth's deep mantle

    SciTech Connect

    Duffy, T S

    2008-12-09

    Understanding planetary structure and evolution requires a detailed knowledge of the properties of geological materials under the conditions of deep planetary interiors. Experiments under the extreme pressure-temperature conditions of the deep mantle are challenging, and many fundamental properties remain poorly constrained or are inferred only through uncertain extrapolations from lower pressure-temperature states. Nevertheless, the last several years have witnessed a number of new developments in this area, and a broad overview of the current understanding of the Earth's lower mantle is presented here. Some recent experimental and theoretical advances related to the lowermost mantle are highlighted. Measurements of the equation of state and deformation behaviour of (Mg,Fe)SiO{sub 3} in the CaIrO{sub 3}-type (post-perovskite) structure yield insights into the nature of the core-mantle boundary region. Theoretical studies of the behaviour of MgSiO3 liquids under high pressure-temperature conditions provide constraints on melt volumes, diffusivities and viscosities that are relevant to understanding both the early Earth (e.g. deep magma oceans) and seismic structure observed in the present Earth (e.g. ultra-low-velocity zones).

  13. Advancing Capabilities for Understanding the Earth System Through Intelligent Systems, the NSF Perspective

    NASA Astrophysics Data System (ADS)

    Gil, Y.; Zanzerkia, E. E.; Munoz-Avila, H.

    2015-12-01

    The National Science Foundation (NSF) Directorate for Geosciences (GEO) and Directorate for Computer and Information Science (CISE) acknowledge the significant scientific challenges required to understand the fundamental processes of the Earth system, within the atmospheric and geospace, Earth, ocean and polar sciences, and across those boundaries. A broad view of the opportunities and directions for GEO are described in the report "Dynamic Earth: GEO imperative and Frontiers 2015-2020." Many of the aspects of geosciences research, highlighted both in this document and other community grand challenges, pose novel problems for researchers in intelligent systems. Geosciences research will require solutions for data-intensive science, advanced computational capabilities, and transformative concepts for visualizing, using, analyzing and understanding geo phenomena and data. Opportunities for the scientific community to engage in addressing these challenges are available and being developed through NSF's portfolio of investments and activities. The NSF-wide initiative, Cyberinfrastructure Framework for 21st Century Science and Engineering (CIF21), looks to accelerate research and education through new capabilities in data, computation, software and other aspects of cyberinfrastructure. EarthCube, a joint program between GEO and the Advanced Cyberinfrastructure Division, aims to create a well-connected and facile environment to share data and knowledge in an open, transparent, and inclusive manner, thus accelerating our ability to understand and predict the Earth system. EarthCube's mission opens an opportunity for collaborative research on novel information systems enhancing and supporting geosciences research efforts. NSF encourages true, collaborative partnerships between scientists in computer sciences and the geosciences to meet these challenges.

  14. Students' Understanding of Advanced Properties of Java Exceptions

    ERIC Educational Resources Information Center

    Rashkovits, Rami; Lavy, Ilana

    2012-01-01

    This study examines how Information Systems Engineering School students on the verge of their graduation understand the mechanism of exception handling. The main contributions of this paper are as follows: we construct a questionnaire aimed at examining students' level of understanding concerning exceptions; we classify and analyse the students'…

  15. Manganese: Recent advances in understanding its transport and neurotoxicity

    SciTech Connect

    Aschner, Michael . E-mail: Michael.Aschner@vanderbilt.edu; Guilarte, Tomas R.; Schneider, Jay S.; Zheng Wei

    2007-06-01

    The present review is based on presentations from the meeting of the Society of Toxicology in San Diego, CA (March 2006). It addresses recent developments in the understanding of the transport of manganese (Mn) into the central nervous system (CNS), as well as brain imaging and neurocognitive studies in non-human primates aimed at improving our understanding of the mechanisms of Mn neurotoxicity. Finally, we discuss potential therapeutic modalities for treating Mn intoxication in humans.

  16. Advances in understanding glycosyltransferases from a structural perspective

    PubMed Central

    Gloster, Tracey M

    2014-01-01

    Glycosyltransferases (GTs), the enzymes that catalyse glycosidic bond formation, create a diverse range of saccharides and glycoconjugates in nature. Understanding GTs at the molecular level, through structural and kinetic studies, is important for gaining insights into their function. In addition, this understanding can help identify those enzymes which are involved in diseases, or that could be engineered to synthesize biologically or medically relevant molecules. This review describes how structural data, obtained in the last 3–4 years, have contributed to our understanding of the mechanisms of action and specificity of GTs. Particular highlights include the structure of a bacterial oligosaccharyltransferase, which provides insights into N-linked glycosylation, the structure of the human O-GlcNAc transferase, and the structure of a bacterial integral membrane protein complex that catalyses the synthesis of cellulose, the most abundant organic molecule in the biosphere. PMID:25240227

  17. Recent Molecular Advances in Our Understanding of Glioma

    PubMed Central

    Pisapia, David

    2015-01-01

    Our molecular understanding of glioma has undergone a sea change over the last decade. In this review, we discuss two recent articles that employed whole genome sequencing to subclassify gliomas vis-à-vis known molecular alterations. We further discuss the relevance of these findings vis-à-vis current treatment paradigms. PMID:26244119

  18. Understanding the operational environment: implications for advanced visualizations

    NASA Astrophysics Data System (ADS)

    Aleva, Denise; Fitzhugh, Elisabeth; Dixon, Sharon

    2009-05-01

    With the changing character of warfare, information superiority is a high priority. Given the complexity of current and future operating environments, analysts, strategists and planners need a multidimensional understanding of the battlespace. Asymmetric warfare necessitates that our strategists look beyond targets-based operations, where we simply identify and destroy enemy entities. Effects-based operations models the enemy as a system which reacts to our actions. This requires the capability to predict the adversary response to a selected action. Actions may be diplomatic, information, military or economic (DIME). Effects may be political, military, economic, social, information or infrastructure (PMESII). Timing must be explicitly considered and effects dynamically assessed. Visualizations of intelligence information are needed which will promote full understanding of all aspects of adversary strengths and weaknesses by providing the extensive data about adversary forces, organic essentials, infrastructure, leadership, population, and science and technology in an easily accessible and understandable format. This will enhance Effectsbased operations, and therefore, the capability to predict and counter adversary courses of action. This paper outlines a systems engineering approach to designing visualizations which convey the multidimensional information to decision makers. Visualization issues inherent in understanding the multidimensional operational environment will be discussed.

  19. A Hydrological Perspective to Advance Understanding of the Water Cycle

    NASA Astrophysics Data System (ADS)

    Berghuijs, W.

    2014-12-01

    In principle hydrologists are scientists that study relationships within the water cycle. Yet, current technology makes it tempting for hydrology students to lose their "hydrological perspective" and become instead full-time computer programmers or statisticians. I assert that students should ensure their hydrological perspective thrives, notwithstanding the importance and possibilities of current technology. This perspective is necessary to advance the science of hydrology. As other hydrologists have pondered similar views before, I make no claims of originality here. I just hope that in presenting my perspective on this issue I may spark the interest of other early career hydrologists.

  20. Addressing fundamental architectural challenges of an activity-based intelligence and advanced analytics (ABIAA) system

    NASA Astrophysics Data System (ADS)

    Yager, Kevin; Albert, Thomas; Brower, Bernard V.; Pellechia, Matthew F.

    2015-06-01

    The domain of Geospatial Intelligence Analysis is rapidly shifting toward a new paradigm of Activity Based Intelligence (ABI) and information-based Tipping and Cueing. General requirements for an advanced ABIAA system present significant challenges in architectural design, computing resources, data volumes, workflow efficiency, data mining and analysis algorithms, and database structures. These sophisticated ABI software systems must include advanced algorithms that automatically flag activities of interest in less time and within larger data volumes than can be processed by human analysts. In doing this, they must also maintain the geospatial accuracy necessary for cross-correlation of multi-intelligence data sources. Historically, serial architectural workflows have been employed in ABIAA system design for tasking, collection, processing, exploitation, and dissemination. These simpler architectures may produce implementations that solve short term requirements; however, they have serious limitations that preclude them from being used effectively in an automated ABIAA system with multiple data sources. This paper discusses modern ABIAA architectural considerations providing an overview of an advanced ABIAA system and comparisons to legacy systems. It concludes with a recommended strategy and incremental approach to the research, development, and construction of a fully automated ABIAA system.

  1. Recent advances in managing and understanding diabetic nephropathy

    PubMed Central

    Tang, Sydney C.W.; Chan, Gary C.W.; Lai, Kar Neng

    2016-01-01

    Diabetic nephropathy is the commonest cause of end-stage renal disease in most developed economies. Current standard of care for diabetic nephropathy embraces stringent blood pressure control via blockade of the renin-angiotensin-aldosterone system and glycemia control. Recent understanding of the pathophysiology of diabetic nephropathy has led to the development of novel therapeutic options. This review article focuses on available data from landmark studies on the main therapeutic approaches and highlights some novel management strategies. PMID:27303648

  2. Recent advances in understanding the pathogenesis of Lawsonia intracellularis infections.

    PubMed

    Vannucci, F A; Gebhart, C J

    2014-03-01

    Proliferative enteropathy is an infectious disease caused by an obligate intracellular bacterium, Lawsonia intracellularis, and characterized by thickening of the intestinal epithelium due to enterocyte proliferation. The disease is endemic in swine herds and has been occasionally reported in various other species. Furthermore, outbreaks among foals began to be reported on breeding farms worldwide within the past 5 years. Cell proliferation is directly associated with bacterial infection and replication in the intestinal epithelium. As a result, mild to severe diarrhea is the major clinical sign described in infected animals. The dynamics of L. intracellularis infection in vitro and in vivo have been well characterized, but little is known about the genetic basis for the pathogenesis or ecology of this organism. The present review focuses on the recent advances regarding the pathogenesis and host-pathogen interaction of L. intracellularis infections. PMID:24476941

  3. Advances in understanding Giardia: determinants and mechanisms of chronic sequelae

    PubMed Central

    Sartor, R. Balfour

    2015-01-01

    Giardia lamblia is a flagellated protozoan that is the most common cause of intestinal parasitic infection in children living in resource-limited settings. The pathogenicity of Giardia has been debated since the parasite was first identified, and clinical outcomes vary across studies. Among recent perplexing findings are diametrically opposed associations between Giardia and acute versus persistent diarrhea and a poorly understood potential for long-term sequelae, including impaired child growth and cognitive development. The mechanisms driving these protean clinical outcomes remain elusive, but recent advances suggest that variability in Giardia strains, host nutritional status, the composition of microbiota, co-infecting enteropathogens, host genetically determined mucosal immune responses, and immune modulation by Giardia are all relevant factors influencing disease manifestations after Giardia infection. PMID:26097735

  4. Using Content-Aligned Assessments to Identify Weaknesses in Students' Understanding of Fundamental Weather and Climate Ideas

    NASA Astrophysics Data System (ADS)

    Wertheim, J.; Willard, S.

    2011-12-01

    ). But a much more prevalent issue is that most students lack schematic knowledge for any concept tested, as demonstrated by results indicative of random guessing on items that require cognitive demands beyond declarative knowledge. For example, 83% of students know that the maximum height of the sun in the sky above a given place can change during July, but only 32% know both that it changes continuously through the month and could correctly identify if it gets higher or lower. These basic elements of an accurate mental model are needed to explain annual temperature patterns. If students do not have an accurate understanding of processes controlling key elements of the climate system, it is unsurprising that they struggle to comprehend how these elements interact within the system itself. The results of this study underscore the need to 1) ensure that fundamentals are given the necessary attention, even as our expectations for students become increasingly sophisticated; 2) define grade appropriate, coherent, functioning conceptual models for each climate idea and for each grade level; and 3) develop instructional materials that build schematic knowledge.

  5. Recent Advances in Understanding the Role of Nutrition in Human Genome Evolution12

    PubMed Central

    Ye, Kaixiong; Gu, Zhenglong

    2011-01-01

    Dietary transitions in human history have been suggested to play important roles in the evolution of mankind. Genetic variations caused by adaptation to diet during human evolution could have important health consequences in current society. The advance of sequencing technologies and the rapid accumulation of genome information provide an unprecedented opportunity to comprehensively characterize genetic variations in human populations and unravel the genetic basis of human evolution. Series of selection detection methods, based on various theoretical models and exploiting different aspects of selection signatures, have been developed. Their applications at the species and population levels have respectively led to the identification of human specific selection events that distinguish human from nonhuman primates and local adaptation events that contribute to human diversity. Scrutiny of candidate genes has revealed paradigms of adaptations to specific nutritional components and genome-wide selection scans have verified the prevalence of diet-related selection events and provided many more candidates awaiting further investigation. Understanding the role of diet in human evolution is fundamental for the development of evidence-based, genome-informed nutritional practices in the era of personal genomics. PMID:22332091

  6. Imaging for understanding speech communication: Advances and challenges

    NASA Astrophysics Data System (ADS)

    Narayanan, Shrikanth

    2005-04-01

    Research in speech communication has relied on a variety of instrumentation methods to illuminate details of speech production and perception. One longstanding challenge has been the ability to examine real-time changes in the shaping of the vocal tract; a goal that has been furthered by imaging techniques such as ultrasound, movement tracking, and magnetic resonance imaging. The spatial and temporal resolution afforded by these techniques, however, has limited the scope of the investigations that could be carried out. In this talk, we focus on some recent advances in magnetic resonance imaging that allow us to perform near real-time investigations on the dynamics of vocal tract shaping during speech. Examples include Demolin et al. (2000) (4-5 images/second, ultra-fast turbo spin echo) and Mady et al. (2001,2002) (8 images/second, T1 fast gradient echo). A recent study by Narayanan et al. (2004) that used a spiral readout scheme to accelerate image acquisition has allowed for image reconstruction rates of 24 images/second. While these developments offer exciting prospects, a number of challenges lie ahead, including: (1) improving image acquisition protocols, hardware for enhancing signal-to-noise ratio, and optimizing spatial sampling; (2) acquiring quality synchronized audio; and (3) analyzing and modeling image data including cross-modality registration. [Work supported by NIH and NSF.

  7. Recent Advances in Understanding Integrative Control of Potassium Homeostasis

    PubMed Central

    Youn, Jang H.; McDonough, Alicia A.

    2016-01-01

    The potassium homeostatic system is very tightly regulated. Recent studies have shed light on the sensing and molecular mechanisms responsible for this tight control. In addition to classic feedback regulation mediated by a rise in extracellular fluid (ECF) [K+], there is evidence for a feedforward mechanism: Dietary K+ intake is sensed in the gut, and an unidentified gut factor is activated to stimulate renal K+ excretion. This pathway may explain renal and extrarenal responses to altered K+ intake that occur independently of changes in ECF [K+]. Mechanisms for conserving ECF K+ during fasting or K+ deprivation have been described: Kidney NADPH oxidase activation initiates a cascade that provokes the retraction of K+ channels from the cell membrane, and muscle becomes resistant to insulin stimulation of cellular K+ uptake. How these mechanisms are triggered by K+ deprivation remains unclear. Cellular AMP kinase–dependent protein kinase activity provokes the acute transfer of K+ from the ECF to the ICF, which may be important in exercise or ischemia. These recent advances may shed light on the beneficial effects of a high-K+ diet for the cardiovascular system. PMID:18759636

  8. Advances in Understanding Bronchiolitis Obliterans After Lung Transplantation.

    PubMed

    Verleden, Stijn E; Sacreas, Annelore; Vos, Robin; Vanaudenaerde, Bart M; Verleden, Geert M

    2016-07-01

    Bronchiolitis obliterans syndrome (BOS) remains a major complication after lung transplantation, causing significant morbidity and mortality in a majority of recipients. BOS is believed to be the clinical correlate of chronic allograft dysfunction, and is defined as an obstructive pulmonary function defect in the absence of other identifiable causes, mostly not amenable to treatment. Recently, it has become clear that BOS is not the only form of chronic allograft dysfunction and that other clinical phenotypes exist; however, we focus exclusively on BOS. Radiologic findings typically demonstrate air trapping, mosaic attenuation, and hyperinflation. Pathologic examination reveals obliterative bronchiolitis lesions and a pure obliteration of the small airways (< 2 mm), with a relatively normal surrounding parenchyma. In this review, we highlight recent advances in diagnosis, pathologic examination, and risk factors, such as microbes, viruses, and antibodies. Although the pathophysiological mechanisms remain largely unknown, we review the role of the airway epithelium and inflammation and the various experimental animal models. We also clarify the clinical and therapeutic implications of these findings. Although significant progress has been made, the exact pathophysiological mechanisms and adequate therapy for posttransplantation BOS remain unknown, highlighting the need for further research to improve long-term posttransplantation BOS-free and overall survival. PMID:27212132

  9. Advances in mechanistic understanding and treatment approaches to Tourette syndrome.

    PubMed

    Shprecher, David R; Kious, Brent M; Himle, Michael H

    2015-11-01

    Tourette syndrome (TS) is a childhood onset neurodevelopmental disorder characterized by semi-involuntary, repetitive movements and sounds (motor and phonic tics). Transient tics in childhood are common, and their persistence in TS may be due to failure of maturation of frontal-subcortical circuits mediated by genetic predisposition and environmental factors. Tic improvement by young adult years is common, but its mechanism and predictive factors are unclear. Though tics can often be managed with nonmedical therapies, pharmacotherapy is often used for refractory, severe, or injurious tics but is complicated by side effects and incomplete benefit. This review summarizes the current understanding of TS pathophysiology, current and future treatment options, and recommendations for future research. PMID:26645901

  10. Advances in understanding and treating dystrophic epidermolysis bullosa

    PubMed Central

    Vanden Oever, Michael J

    2014-01-01

    Epidermolysis bullosa is a group of inherited disorders that can be both systemic and life-threatening. Standard treatments for the most severe forms of this disorder, typically limited to palliative care, are ineffective in reducing the morbidity and mortality due to complications of the disease. Emerging therapies—such as the use of allogeneic cellular therapy, gene therapy, and protein therapy—have all shown promise, but it is likely that several approaches will need to be combined to realize a cure. For recessive dystrophic epidermolysis bullosa, each particular therapeutic approach has added to our understanding of type VII collagen (C7) function and the basic biology surrounding the disease. The efficacy of these therapies and the mechanisms by which they function also give us insight into developing future strategies for treating this and other extracellular matrix disorders. PMID:24860657

  11. Recent Advances in Understanding and Managing Tourette Syndrome.

    PubMed

    Thenganatt, Mary Ann; Jankovic, Joseph

    2016-01-01

    Tourette syndrome (TS) is a neurologic and behavioral disorder consisting of motor and phonic tics with onset in childhood or adolescence. The severity of tics can range from barely perceptible to severely impairing due to social embarrassment, discomfort, self-injury, and interference with daily functioning and school or work performance. In addition to tics, most patients with TS have a variety of behavioral comorbidities, including attention deficit hyperactivity disorder and obsessive-compulsive disorder. Studies evaluating the pathophysiology of tics have pointed towards dysfunction of the cortico-striato-thalamo-cortical circuit, but the mechanism of this hyperkinetic movement disorder is not well understood. Treatment of TS is multidisciplinary, typically involving behavioral therapy, oral medications, and botulinum toxin injections. Deep brain stimulation may be considered for "malignant" TS that is refractory to conventional therapy. In this review, we will highlight recent developments in the understanding and management strategies of TS. PMID:26918185

  12. Recent advances in the understanding and management of rosacea

    PubMed Central

    2014-01-01

    Rosacea is a chronic relapsing inflammatory facial dermatosis. There are several known triggers but the pathogenesis remains unknown. Recent achievements in understanding this disease point to the importance of skin-environmental interactions. This includes physical and chemical factors, but also microbial factors. The impairment of the skin barrier function and the activation of the innate immune defences are major and connected pathways contributing to an ongoing inflammatory response in the affected skin. This becomes modulated by endogenous factors like neurovascular, drugs, and psychological factors. These factors offer new therapeutic targets for rosacea treatment. There is a broader range of anti-inflammatory compounds available with a favourable safety record. Only recently have persistent erythema and flushing been addressed by new drug formulations. PMID:25184040

  13. Advances in the Understanding of Cobalamin Assimilation and Metabolism

    PubMed Central

    Quadros, Edward V.

    2009-01-01

    Summary The haematological and neurological consequences of cobalamin deficiency define the essential role of this vitamin in key metabolic reactions. The identification of cubilin-amnionless as the receptors for intestinal absorption of intrinsic factor-bound cobalamin and the plasma membrane receptor for cellular uptake of transcobalamin bound cobalamin have provided a clearer understanding of the absorption and cellular uptake of this vitamin. As the genes involved in the intracellular processing of cobalamins and genetic defects of these pathways are identified, the metabolic disposition of cobalamins and the proteins involved are being recognized. The synthesis of methylcobalamin and 5’deoxyadenosylcobalamin, their utilization in conjunction with methionine synthase and methylmalonylCoA mutase, respectively, and the metabolic consequences of defects in these pathways could provide insights into the clinical presentation of cobalamin deficiency. PMID:19832808

  14. Understanding type 1 diabetes through genetics: advances and prospects.

    PubMed

    Polychronakos, Constantin; Li, Quan

    2011-11-01

    Starting with early crucial discoveries of the role of the major histocompatibility complex, genetic studies have long had a role in understanding the biology of type 1 diabetes (T1D), which is one of the most heritable common diseases. Recent genome-wide association studies (GWASs) have given us a clearer picture of the allelic architecture of genetic susceptibility to T1D. Fine mapping and functional studies are gradually revealing the complex mechanisms whereby immune self-tolerance is lost, involving multiple aspects of adaptive immunity. The triggering of these events by dysregulation of the innate immune system has also been implicated by genetic evidence. Finally, genetic prediction of T1D risk is showing promise of use for preventive strategies. PMID:22005987

  15. Advances in our understanding of mechanisms of venous thrombus resolution.

    PubMed

    Altmann, Johanna; Sharma, Smriti; Lang, Irene M

    2016-01-01

    Traditionally, venous thrombosis has been seen as the consequence of a regulated cascade of proteolytic steps leading to the polymerization of fibrinogen and fibrin crosslinking that is facilitated by platelets. A new view of thrombosis is providing a more integrated concept, with components of the vascular wall contributing to the vascular remodeling of thrombosis. Angiogenesis and inflammation are two key mechanisms that safeguard venous thrombus resolution and restitution of vascular patency after thrombosis. Disturbance of these processes leads to thrombus persistence and has potentially severe consequences for affected patients. Examples for clinical conditions associated with recurrent or persisting venous thrombosis are post-thrombotic syndrome or chronic thromboembolic pulmonary hypertension. Recently, studies using animal models of venous thrombosis have contributed to a better understanding of thrombus non-resolution that will eventually lead to modification of current treatment concepts. For example, recent data suggest that innate immunity is involved in the modification of thrombosis. PMID:26629617

  16. Recent Advances in Understanding and Managing Tourette Syndrome

    PubMed Central

    Thenganatt, Mary Ann; Jankovic, Joseph

    2016-01-01

    Tourette syndrome (TS) is a neurologic and behavioral disorder consisting of motor and phonic tics with onset in childhood or adolescence. The severity of tics can range from barely perceptible to severely impairing due to social embarrassment, discomfort, self-injury, and interference with daily functioning and school or work performance. In addition to tics, most patients with TS have a variety of behavioral comorbidities, including attention deficit hyperactivity disorder and obsessive-compulsive disorder. Studies evaluating the pathophysiology of tics have pointed towards dysfunction of the cortico-striato-thalamo-cortical circuit, but the mechanism of this hyperkinetic movement disorder is not well understood. Treatment of TS is multidisciplinary, typically involving behavioral therapy, oral medications, and botulinum toxin injections. Deep brain stimulation may be considered for “malignant” TS that is refractory to conventional therapy. In this review, we will highlight recent developments in the understanding and management strategies of TS. PMID:26918185

  17. Recent Advances in Understanding Radiation Damage in Reactor Cavity Concrete

    SciTech Connect

    Rosseel, Thomas M; Field, Kevin G; Le Pape, Yann; Remec, Igor; Giorla, Alain B; Wall, Dr. James Joseph

    2015-01-01

    License renewal up to 60 years and the possibility of subsequent license renewal to 80 years has resulted in a renewed focus on long-term aging of materials at nuclear power plants (NPPs) including concrete. Large irreplaceable sections of most nuclear generating stations include concrete. The Expanded Materials Degradation Analysis, jointly performed by the Department of Energy, the Nuclear Regulatory Commission and Nuclear Industry, identified the urgent need to develop a consistent knowledge base on irradiation effects in concrete (Graves et al., (2014)). Much of the historical mechanical performance data of irradiated concrete (Hilsdorf et al., (1978)) does not accurately reflect typical radiation conditions in NPPs or conditions out to 60 or 80 years of radiation exposure (Kontani et al., (2011)). To address these potential gaps in the knowledge base, the Electric Power Research Institute and Oak Ridge National Laboratory, are working to better understand radiation damage as a degradation mechanism. This paper outlines recent progress toward: 1) assessing the radiation environment in concrete biological shields and defining the upper bound of the neutron and gamma dose levels expected in the biological shield for extended operation, and estimating adsorbed dose, 2) evaluating opportunities to harvest and test irradiated concrete from international NPPs, 3) evaluating opportunities to irradiate prototypical concrete and its components under accelerated neutron and gamma dose levels to establish conservative bounds and inform damage models, 4) developing improved models to enhance the understanding of the effects of radiation on concrete and 5) establishing an international collaborative research and information exchange effort to leverage capabilities and knowledge including developing cooperative test programs to improve confidence in data obtained from various concretes and from accelerated irradiation experiments.

  18. Fundamental Research on Percussion Drilling: Improved rock mechanics analysis, advanced simulation technology, and full-scale laboratory investigations

    SciTech Connect

    Michael S. Bruno

    2005-12-31

    This report summarizes the research efforts on the DOE supported research project Percussion Drilling (DE-FC26-03NT41999), which is to significantly advance the fundamental understandings of the physical mechanisms involved in combined percussion and rotary drilling, and thereby facilitate more efficient and lower cost drilling and exploration of hard-rock reservoirs. The project has been divided into multiple tasks: literature reviews, analytical and numerical modeling, full scale laboratory testing and model validation, and final report delivery. Literature reviews document the history, pros and cons, and rock failure physics of percussion drilling in oil and gas industries. Based on the current understandings, a conceptual drilling model is proposed for modeling efforts. Both analytical and numerical approaches are deployed to investigate drilling processes such as drillbit penetration with compression, rotation and percussion, rock response with stress propagation, damage accumulation and failure, and debris transportation inside the annulus after disintegrated from rock. For rock mechanics modeling, a dynamic numerical tool has been developed to describe rock damage and failure, including rock crushing by compressive bit load, rock fracturing by both shearing and tensile forces, and rock weakening by repetitive compression-tension loading. Besides multiple failure criteria, the tool also includes a damping algorithm to dissipate oscillation energy and a fatigue/damage algorithm to update rock properties during each impact. From the model, Rate of Penetration (ROP) and rock failure history can be estimated. For cuttings transport in annulus, a 3D numerical particle flowing model has been developed with aid of analytical approaches. The tool can simulate cuttings movement at particle scale under laminar or turbulent fluid flow conditions and evaluate the efficiency of cutting removal. To calibrate the modeling efforts, a series of full-scale fluid hammer

  19. Recent advances in understanding myelofibrosis and essential thrombocythemia

    PubMed Central

    Vainchenker, William; Constantinescu, Stefan N.; Plo, Isabelle

    2016-01-01

    The classic BCR-ABL-negative myeloproliferative neoplasms (MPNs), a form of chronic malignant hemopathies, have been classified into polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). ET and PMF are two similar disorders in their pathogenesis, which is marked by a key role of the megakaryocyte (MK) lineage. Whereas ET is characterized by MK proliferation, PMF is also associated with aberrant MK differentiation (myelodysplasia), leading to the release of cytokines in the marrow environment, which causes the development of myelofibrosis. Thus, PMF is associated with both myeloproliferation and different levels of myelodysplastic features. MPNs are mostly driven by mutated genes called MPN drivers, which abnormally activate the cytokine receptor/JAK2 pathway and their downstream effectors. The recent discovery of CALR mutations has closed a gap in our knowledge and has shown that this mutated endoplasmic reticulum chaperone activates the thrombopoietin receptor MPL and JAK2. These genetic studies have shown that there are two main types of MPNs: JAK2V617F-MPNs, including ET, PV, and PMF, and the MPL-/CALR-MPNs, which include only ET and PMF. These MPN driver mutations are associated with additional mutations in genes involved in epigenetics, splicing, and signaling, which can precede or follow the acquisition of MPN driver mutations. They are involved in clonal expansion or phenotypic changes or both, leading to myelofibrosis or leukemic transformation or both. Only a few patients with ET exhibit mutations in non-MPN drivers, whereas the great majority of patients with PMF harbor one or several mutations in these genes. However, the entire pathogenesis of ET and PMF may also depend on other factors, such as the patient’s constitutional genetics, the bone marrow microenvironment, the inflammatory response, and age. Recent advances allowed a better stratification of these diseases and new therapeutic approaches with the

  20. Fundamental Understanding of the Interaction of Acid Gases with CeO2 : From Surface Science to Practical Catalysis

    DOE PAGESBeta

    Tumuluri, Uma; Rother, Gernot; Wu, Zili

    2016-03-21

    Acid gases including CO2, SO2, and NOx are ubiquitous in large-scale energy applications including heterogeneous catalysis. The adverse environmental and health effects of these acid gases have resulted in high interest in the research and development of technologies to remove or convert these acid gases. The main challenge for the development of these technologies is to develop catalysts that are highly efficient, stable, and cost-effective, and many catalysts have been reported in this regard. CeO2 and CeO2-based catalysts have gained prominence in the removal and conversion of CO2, SO2, and NOx because of their structural robustness and redox and acid–basemore » properties. In this article, we provide a brief overview of the application of CeO2 and CeO2-based catalysts for the removal of CO2, SO2, and NOx gases with an emphasis on the fundamental understanding of the interactions of these acid gases with CeO2. The studies summarized in this review range from surface science using single crystals and thin films with precise crystallographic planes to practical catalysis applications of nanocrystalline and polycrystalline CeO2 materials with defects and dopants. After an introduction to the properties of CeO2 surfaces, their catalytic properties for conversions of different acid gases are reviewed and discussed. Lastly, we find that the surface atomic structure, oxygen vacancies, and surface acid–base properties of CeO2 play vital roles in the surface chemistry and structure evolution during the interactions of acid gases with CeO2 and CeO2-based catalysts.« less

  1. Electron collisions with atoms, ions, molecules, and surfaces: Fundamental science empowering advances in technology.

    PubMed

    Bartschat, Klaus; Kushner, Mark J

    2016-06-28

    Electron collisions with atoms, ions, molecules, and surfaces are critically important to the understanding and modeling of low-temperature plasmas (LTPs), and so in the development of technologies based on LTPs. Recent progress in obtaining experimental benchmark data and the development of highly sophisticated computational methods is highlighted. With the cesium-based diode-pumped alkali laser and remote plasma etching of Si3N4 as examples, we demonstrate how accurate and comprehensive datasets for electron collisions enable complex modeling of plasma-using technologies that empower our high-technology-based society. PMID:27317740

  2. Advances in the Understanding and Treatment of Head Injury

    PubMed Central

    Evans, Joseph P.

    1966-01-01

    The author describes his personal involvement in head injury prevention and management over the past 40 years. He reviews the evolution of knowledge concerning the role of increased intracranial pressure, and considers the importance of cerebral vasoparalysis in the production of signs and symptoms following head injury, and the development of methods of recording intracranial pressure continuously, over hours and days. The development of an experimental compression model has led to a fuller understanding of edema of the brain and has provided a means of studying, by light and electron microscopy, the histological changes that result from edema. More recently, analyses of biochemical changes and disturbed membrane function have opened up a new avenue of potential treatment. Moreover, it is now clear that cerebral vascular dilatation and abrupt pressure increase can be produced in the monkey, in over 50% of cases, by lesions in the dorsomedial nucleus of the hypothalamus. Similar lesions may occur in the human and this suggests other therapeutic approaches. There is, then, a genuine hope of a breakthrough in the management of head injuries. ImagesFig. 1Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 16Fig. 21 PMID:5928533

  3. Reef sharks: recent advances in ecological understanding to inform conservation.

    PubMed

    Osgood, G J; Baum, J K

    2015-12-01

    Sharks are increasingly being recognized as important members of coral-reef communities, but their overall conservation status remains uncertain. Nine of the 29 reef-shark species are designated as data deficient in the IUCN Red List, and three-fourths of reef sharks had unknown population trends at the time of their assessment. Fortunately, reef-shark research is on the rise. This new body of research demonstrates reef sharks' high site restriction, fidelity and residency on coral reefs, their broad trophic roles connecting reef communities and their high population genetic structure, all information that should be useful for their management and conservation. Importantly, recent studies on the abundance and population trends of the three classic carcharhinid reef sharks (grey reef shark Carcharhinus amblyrhynchos, blacktip reef shark Carcharhinus melanopterus and whitetip reef shark Triaenodon obesus) may contribute to reassessments identifying them as more vulnerable than currently realized. Because over half of the research effort has focused on only these three reef sharks and the nurse shark Ginglymostoma cirratum in only a few locales, there remain large taxonomic and geographic gaps in reef-shark knowledge. As such, a large portion of reef-shark biodiversity remains uncharacterized despite needs for targeted research identified in their red list assessments. A research agenda for the future should integrate abundance, life history, trophic ecology, genetics, habitat use and movement studies, and expand the breadth of such research to understudied species and localities, in order to better understand the conservation requirements of these species and to motivate effective conservation solutions. PMID:26709218

  4. Advances in understanding and utilising ELM control in JET

    NASA Astrophysics Data System (ADS)

    Chapman, I. T.; de la Luna, E.; Lang, P. T.; Liang, Y.; Alper, B.; Denner, P.; Frigione, D.; Garzotti, L.; Ham, C. J.; Huijsmans, G. T. A.; Jachmich, S.; Kocsis, G.; Lennholm, M.; Lupelli, I.; Rimini, F. G.; Sips, A. C. C.; Contributors, JET

    2016-01-01

    Edge localised mode (ELM) control may be essential to develop ITER scenarios with a reasonable lifetime of divertor components, whilst ELM pacing may be essential to develop stationary ITER scenarios with a tungsten divertor. Resonant magnetic perturbations (RMPs) have mitigated ELMs in high collisionality plasmas in JET. The efficacy of RMPs in mitigating the ELMs is found to depend on plasma shaping, with the change in magnetic boundary achieved when non-axisymmetric fields are applied facilitating access to small ELM regimes. The understanding of ELM pacing by vertical kicks or pellets has also been improved in a range of pedestal conditions in JET ({{T}\\text{ped}}=0.7 –1.3 keV) encompassing the ITER-expected domain ({β\\text{N}}=1.4 –2.4, H 98(y, 2)  =  0.8–1.2, {{f}\\text{GW}}∼ 0.7 ). ELM triggering is reliable provided the perturbation is above a threshold which depends on pedestal parameters. ELM triggering is achieved even in the first 10% of the natural ELM cycle suggesting no inherent maximum frequency. At high normalised pressure, the peeling-ballooning modes are stabilised as predicted by ELITE, necessitating a larger perturbation from either kicks or pellets in order to trigger ELMs. Both kicks and pellets have been used to pace ELMs for tungsten flushing. This has allowed stationary plasma conditions with low gas injection in plasmas where the natural ELM frequency is such that it would normally preclude stationary conditions.

  5. Beyond vascular inflammation--recent advances in understanding atherosclerosis.

    PubMed

    Wolf, Dennis; Zirlik, Andreas; Ley, Klaus

    2015-10-01

    Atherosclerosis is the most life-threatening pathology worldwide. Its major clinical complications, stroke, myocardial infarction, and heart failure, are on the rise in many regions of the world--despite considerable progress in understanding cause, progression, and consequences of atherosclerosis. Originally perceived as a lipid-storage disease of the arterial wall (Die cellularpathologie in ihrer begründung auf physiologische und pathologische gewebelehre. August Hirschwald Verlag Berlin, [1871]), atherosclerosis was recognized as a chronic inflammatory disease in 1986 (New Engl J Med 314:488-500, 1986). The presence of lymphocytes in atherosclerotic lesions suggested autoimmune processes in the vessel wall (Clin Exp Immunol 64:261-268, 1986). Since the advent of suitable mouse models of atherosclerosis (Science 258:468-471, 1992; Cell 71:343-353, 1992; J Clin Invest 92:883-893, 1993) and the development of flow cytometry to define the cellular infiltrate in atherosclerotic lesions (J Exp Med 203:1273-1282, 2006), the origin, lineage, phenotype, and function of distinct inflammatory cells that trigger or inhibit the inflammatory response in the atherosclerotic plaque have been studied. Multiphoton microscopy recently enabled direct visualization of antigen-specific interactions between T cells and antigen-presenting cells in the vessel wall (J Clin Invest 122:3114-3126, 2012). Vascular immunology is now emerging as a new field, providing evidence for protective as well as damaging autoimmune responses (Int Immunol 25:615-622, 2013). Manipulating inflammation and autoimmunity both hold promise for new therapeutic strategies in cardiovascular disease. Ongoing work (J Clin Invest 123:27-36, 2013; Front Immunol 2013; Semin Immunol 31:95-101, 2009) suggests that it may be possible to develop antigen-specific immunomodulatory prevention and therapy-a vaccine against atherosclerosis. PMID:26100516

  6. Recent advances in the understanding of homogeneous dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Massines, F.; Gherardi, N.; Naudé, N.; Ségur, P.

    2009-08-01

    This paper is a state of the art of the understanding on the physics of homogeneous dielectric barrier discharges at atmospheric pressure. It is based on the analysis of present and previous work about the behavior of these discharges and the conditions to get them. Mechanisms controlling the homogeneity during gas breakdown and discharge development are successively discussed. The breakdown has to be a Townsend one, the ionization has to be slow enough to avoid a large avalanche development. During the breakdown, the discharge homogeneity is related to the ratio of the secondary emission at the cathode (γ coefficient) on the ionization in the gas bulk (α coefficient). Higher is this ratio, higher is the pressure × gas gap product (Pd) value for which a Townsend breakdown is obtained. Among the phenomena enhancing the secondary emission there is the negative charge of the dielectric on the cathode surface, the trapping of ions in the gas and the existence of excited state having a long lifetime compared to the time between two consecutive discharges. The first phenomenon is always present when the electrodes are covered by a solid dielectric, the second one is related to the formation of a positive column and the third one is specific of the gas. During the discharge development, the homogeneity is mainly controlled by the voltage or the current imposed by the electrical circuit/electrode configuration and by the gas ability to be slowly ionized. Larger is the contribution of a multiple step ionization process like Penning ionization, higher will be the working domain of the discharge. A decrease of the gas voltage during the discharge development is a solution to enhance the contribution of this process. After 20 years of research a lot of mechanisms have been understood however there is still open questions like the nature of the Inhibited homogeneous DBD, surface energy transfers, role of attachment and detachment...

  7. Fundamentals of the advanced Fresnel tracer used for two-dimensional in-process micromeasurements

    NASA Astrophysics Data System (ADS)

    Huhnke, Burkhard; Urbschat, Gunnar

    1998-12-01

    The drive to short development times and closed-loop process control has created a demand for new tools to collect the needed dimensional data. Optical technologies in fields such as sensors, signal processing, metrology, and instrumentation offer unique solutions to many areas of monitoring, diagnostics and control. The Advanced Fresnel Tracer (AFT), an innovative instrumentation for in-process micromeasurement consisting of a smart optical sensors and an automatic follow-up system, based on a temperature controlled grated glass scale or interferometer will be presented. This device may readily be integrated into a turning or grinding machine, e.g. for the needs of quality assurance and to enable an on-line automatic compensation of diameter deviations/1/2. The device contains an optical Fresnel diffraction sensor allowing a fast measurement of the surface topography, achieving three goals: 1) improvement of the instantaneous diameter measurement, 2) surface quality inspection, and 3) determination of the edge gradient or the waviness of the workpiece. The new compact, smart, and precise optical multiparamter sensor, the AFT has been developed and tested.

  8. Optical Second Harmonic Generation in Plasmonic Nanostructures: From Fundamental Principles to Advanced Applications.

    PubMed

    Butet, Jérémy; Brevet, Pierre-François; Martin, Olivier J F

    2015-11-24

    Plasmonics has emerged as an important research field in nanoscience and nanotechnology. Recently, significant attention has been devoted to the observation and the understanding of nonlinear optical processes in plasmonic nanostructures, giving rise to the new research field called nonlinear plasmonics. This review provides a comprehensive insight into the physical mechanisms of one of these nonlinear optical processes, namely, second harmonic generation (SHG), with an emphasis on the main differences with the linear response of plasmonic nanostructures. The main applications, ranging from the nonlinear optical characterization of nanostructure shapes to the optimization of laser beams at the nanoscale, are summarized and discussed. Future directions and developments, made possible by the unique combination of SHG surface sensitivity and field enhancements associated with surface plasmon resonances, are also addressed. PMID:26474346

  9. What I Wish: Three Advancement Professionals Discuss What Their Colleagues Need to Understand about Their Jobs

    ERIC Educational Resources Information Center

    Gurd, Andy; Peirce, Susan; Morris, Sarah

    2012-01-01

    Three advancement professionals discuss what their colleagues need to understand about their jobs. The Ohio State University Alumni Association is currently integrating into the university's advancement office at the behest of the board of trustees, so Andy Gurd is now working more closely with his development and communications colleagues than…

  10. BOOK REVIEW: New Understanding Physics for Advanced Level

    NASA Astrophysics Data System (ADS)

    Breithaupt, Jim

    2000-09-01

    Breithaupt's new book is big: at 727 pages, it will be a hefty addition to any student's bag. According to the preface, the book is designed to help students achieve the transition from GCSE to A-level and to succeed well at this level. It also aims to cover the requirements of the compulsory parts of all new syllabuses and to cover most of the optional material, too. The book is organized into seven themes along traditional lines: mechanics, materials, fields, waves, electricity, inside the atom, and physics in medicine. Each theme begins with a colourful title page that outlines what the theme is about, lists the applications that students will meet in their reading, identifies prior learning from GCSE and gives a checklist of what students should be able to do once they have finished their reading of the theme. This is all very useful. The text of the book is illustrated with many colourful photographs, pictures and cartoons, but despite this it looks very dense. There are a lot of words on every page in a small font that makes them seem very unfriendly, and although the book claims to be readable I rather doubt that the layout will encourage voluntary reading of the text. Each chapter ends with a useful summary and a selection of short questions that allow students to test their understanding. Each theme has a set of multiple choice and long questions. Some of the questions have an icon referring the student to the accompanying CD (more of this later). There is much up-to-date material in the book. For example, the section on cosmology gives a brief description of the inflationary scenario within the Big Bang model of the origin of the universe, although no mechanism for the inflation is given, which might prove unsatisfying to some students. I do have some reservations about the presentation of some topics within the book: the discussion of relativistic mass, for example, states that `Einstein showed that the mass ... is given by the formula ...' and quotes

  11. Dosimetric validation of the Acuros XB Advanced Dose Calculation algorithm: fundamental characterization in water

    NASA Astrophysics Data System (ADS)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Mancosu, Pietro; Cozzi, Luca

    2011-05-01

    This corrigendum intends to clarify some important points that were not clearly or properly addressed in the original paper, and for which the authors apologize. The original description of the first Acuros algorithm is from the developers, published in Physics in Medicine and Biology by Vassiliev et al (2010) in the paper entitled 'Validation of a new grid-based Boltzmann equation solver for dose calculation in radiotherapy with photon beams'. The main equations describing the algorithm reported in our paper, implemented as the 'Acuros XB Advanced Dose Calculation Algorithm' in the Varian Eclipse treatment planning system, were originally described (for the original Acuros algorithm) in the above mentioned paper by Vassiliev et al. The intention of our description in our paper was to give readers an overview of the algorithm, not pretending to have authorship of the algorithm itself (used as implemented in the planning system). Unfortunately our paper was not clear, particularly in not allocating full credit to the work published by Vassiliev et al on the original Acuros algorithm. Moreover, it is important to clarify that we have not adapted any existing algorithm, but have used the Acuros XB implementation in the Eclipse planning system from Varian. In particular, the original text of our paper should have been as follows: On page 1880 the sentence 'A prototype LBTE solver, called Attila (Wareing et al 2001), was also applied to external photon beam dose calculations (Gifford et al 2006, Vassiliev et al 2008, 2010). Acuros XB builds upon many of the methods in Attila, but represents a ground-up rewrite of the solver where the methods were adapted especially for external photon beam dose calculations' should be corrected to 'A prototype LBTE solver, called Attila (Wareing et al 2001), was also applied to external photon beam dose calculations (Gifford et al 2006, Vassiliev et al 2008). A new algorithm called Acuros, developed by the Transpire Inc. group, was

  12. A Case Study on Advanced Technology: Understanding the Impact of Advanced Technology on Student Performance

    ERIC Educational Resources Information Center

    Morris, Jill Sellars

    2010-01-01

    While research has focused on the effect of technology on student performance, it is not yet known how advanced technology, such as Promethean boards influence student achievement. The purpose of this mixed-method study was to examine how Promethean boards impact academic performance of elementary school students in third and fifth grade…

  13. From Fundamental Understanding To Predicting New Nanomaterials For High Capacity Hydrogen/Methane Storage and Carbon Capture

    SciTech Connect

    Yildirim, Taner

    2015-03-03

    On-board hydrogen/methane storage in fuel cell-powered vehicles is a major component of the national need to achieve energy independence and protect the environment. The main obstacles in hydrogen storage are slow kinetics, poor reversibility and high dehydrogenation temperatures for the chemical hydrides; and very low desorption temperatures/energies for the physisorption materials (MOF’s, porous carbons). Similarly, the current methane storage technologies are mainly based on physisorption in porous materials but the gravimetric and volumetric storage capacities are below the target values. Finally, carbon capture, a critical component of the mitigation of CO2 emissions from industrial plants, also suffers from similar problems. The solid-absorbers such as MOFs are either not stable against real flue-gas conditions and/or do not have large enough CO2 capture capacity to be practical and cost effective. In this project, we addressed these challenges using a unique combination of computational, synthetic and experimental methods. The main scope of our research was to achieve fundamental understanding of the chemical and structural interactions governing the storage and release of hydrogen/methane and carbon capture in a wide spectrum of candidate materials. We studied the effect of scaffolding and doping of the candidate materials on their storage and dynamics properties. We reviewed current progress, challenges and prospect in closely related fields of hydrogen/methane storage and carbon capture.[1-5] For example, for physisorption based storage materials, we show that tap-densities or simply pressing MOFs into pellet forms reduce the uptake capacities by half and therefore packing MOFs is one of the most important challenges going forward. For room temperature hydrogen storage application of MOFs, we argue that MOFs are the most promising scaffold materials for Ammonia-Borane (AB) because of their unique interior active metal-centers for AB binding and well

  14. Towards integrated approaches to advance understanding of ecohydrological systems across scales

    NASA Astrophysics Data System (ADS)

    Tetzlaff, Doerthe; Soulsby, Chris

    2016-04-01

    It is increasingly recognised that the processes and connections in our landscapes are influencing the functioning of aquatic ecosystems. Fundamental scientific understanding of the functioning of both aquatic and terrestrial ecosystems is required for an integrated and sustainable management of landscapes and riverscapes to maintain their ecosystem services and biological integrity at multiple scales. This talk will show how the interactions and feedbacks in ecohydrological systems can be quantitatively assessed through a number of novel, integrated approaches. Importantly, this talk will discuss the need to understand the role of vegetation on water partitioning at the terrestrial and aquatic interface. Terrestrial and aquatic ecosystems are interacting at every scale level and cross-scale investigations are extremely useful to gain an integrated understanding of ecohydrological systems. Environmental tracers are valuable tools to understand the functioning of ecohydrological systems at the landscape scale in terms of understand flow paths, sources of water and associated biogeochemical interactions. Extensive empirical studies were conducted at the plot and hillslope scale to understand ecohydrological systems, and in particular, soil-vegetation-water interlinkages. This empirically based understanding was then integrated into spatially distributed, tracer-aided models to understand mixing of water, flows to the stream and water age distribution at the catchment scale. Finally, remote sensing techniques were used to integrate empirically based findings and to extrapolate system understanding to cross-regional scales, specifically in terms of studying hydroclimatic variability, vegetation dynamics and consequent changes of plant water use and water partitioning.

  15. Advances in the understanding of dairy and cheese flavors: Symposium Introduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A symposium titled “Advances in the Understanding of Dairy and Cheese Flavors” was held in September 2013 at the American Chemical Society’s 246th National Meeting in Indianapolis, IN. The symposium, which was sponsored by the Division of Agricultural and Food Chemistry, was to discuss the state of...

  16. The Effect of Explicit Embedded Reflective Instruction on Nature of Science Understandings in Advanced Science Students

    ERIC Educational Resources Information Center

    Koksal, Mustafa Serdar; Cakiroglu, Jale; Geban, Omer

    2013-01-01

    The purpose of this study is to investigate the effectiveness of explicit-embedded-reflective (EER) instruction in nature of science (NOS) understandings of ninth-grade advanced science students. This study was conducted with 71 students, who were divided into three groups, by using non-equivalent quasi-experimental design. In the treatment…

  17. Recent Advances in Our Understanding of the Environmental, Epidemiological, Immunological, and Clinical Dimensions of Coccidioidomycosis

    PubMed Central

    Nguyen, Chinh; Barker, Bridget Marie; Hoover, Susan; Nix, David E.; Ampel, Neil M.; Frelinger, Jeffrey A.; Orbach, Marc J.

    2013-01-01

    SUMMARY Coccidioidomycosis is the endemic mycosis caused by the fungal pathogens Coccidioides immitis and C. posadasii. This review is a summary of the recent advances that have been made in the understanding of this pathogen, including its mycology, genetics, and niche in the environment. Updates on the epidemiology of the organism emphasize that it is a continuing, significant problem in areas of endemicity. For a variety of reasons, the number of reported coccidioidal infections has increased dramatically over the past decade. While continual improvements in the fields of organ transplantation and management of autoimmune disorders and patients with HIV have led to dilemmas with concurrent infection with coccidioidomycosis, they have also led to advances in the understanding of the human immune response to infection. There have been some advances in therapeutics with the increased use of newer azoles. Lastly, there is an overview of the ongoing search for a preventative vaccine. PMID:23824371

  18. Modeling of fundamental phenomena in welds

    SciTech Connect

    Zacharia, T.; Vitek, J.M.; Goldak, J.A.; DebRoy, T.A.; Rappaz, M.; Bhadeshia, H.K.D.H.

    1993-12-31

    Recent advances in the mathematical modeling of fundamental phenomena in welds are summarized. State-of-the-art mathematical models, advances in computational techniques, emerging high-performance computers, and experimental validation techniques have provided significant insight into the fundamental factors that control the development of the weldment. The current status and scientific issues in the areas of heat and fluid flow in welds, heat source metal interaction, solidification microstructure, and phase transformations are assessed. Future research areas of major importance for understanding the fundamental phenomena in weld behavior are identified.

  19. Final Report: DE- FC36-05GO15063, Fundamental Studies of Advanced High-Capacity, Reversible Metal Hydrides

    SciTech Connect

    Jensen, Craig; McGrady, Sean; Severa, Godwin; Eliseo, Jennifer; Chong, Marina

    2015-02-08

    The project was component of the US DOE, Metal Hydride Center of Excellence (MHCoE). The Sandia National Laboratory led center was established to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE/FreedomCAR 2010 and 2015 system targets for hydrogen storage materials. Our approach entailed a wide variety of activities ranging from synthesis, characterization, and evaluation of new candidate hydrogen storage materials; screening of catalysts for high capacity materials requiring kinetics enhancement; development of low temperature methods for nano-confinement of hydrides and determining its effects on the kinetics and thermodynamics of hydrides; and development of novel processes for the direct re-hydrogenation of materials. These efforts have resulted in several advancements the development of hydrogen storage materials. We have greatly extended the fundamental knowledge about the highly promising hydrogen storage carrier, alane (AlH₃), by carrying out the first crystal structure determinations and the first determination of the heats of dehydrogenation of β–AlH₃ and γ-AlD₃. A low-temperature homogenous organometallic approach to incorporation of Al and Mg based hydrides into carbon aerogels has been developed that that allows high loadings without degradation of the nano-porous scaffold. Nano-confinement was found to significantly improve the dehydrogenation kinetics but not effect the enthalpy of dehydrogenation. We conceived, characterized, and synthesized a novel class of potential hydrogen storage materials, bimetallic borohydrides. These novel compounds were found to have many favorable properties including release of significant amounts of hydrogen at moderate temperatures (75-190ºC). However, in situ IR studies in tandem with thermal gravimetric analysis have shown that about 0.5 equivalents of diborane are released during the dehydrogenation making re

  20. Illness understanding in patients with advanced lung cancer: curse or blessing?

    PubMed

    Janssens, Annelies; Kohl, Sisca; Michielsen, Toke; Van Langendonck, Shana; Hiddinga, Birgitta I; van Meerbeeck, Jan P

    2016-04-01

    Early palliative care (EPC) should be introduced from the start of the treatment of patients with advanced lung cancer. Unfortunately, this is often not integrated in daily oncologic care. This letter wants to emphasize the importance of offering a holistic approach, meaning EPC to optimize quality of life (QoL). Illness understanding is important because patients with better understanding of their disease choose more often for symptom control and less for an aggressive treatment at the end of life. This illness understanding should be achieved during communication with the treating oncologist. Based on the limited available literature about illness understanding, it seems that an EPC program is necessary when breaking bad news, in order to maintain or improve QoL in patients. PMID:27121741

  1. Improving the Fundamental Understanding of Regional Seismic Signal Processing with a Unique Western U.S. Dataset

    SciTech Connect

    Walter, W R; Smith, K; O'Boyle, J; Hauk, T F; Ryall, F; Ruppert, S D; Myers, S C; Anderson, M; Dodge, D A

    2003-07-18

    This project has built a unique historic database of regional distance nuclear explosion, earthquake, and mine-related digital broadband seismograms for the western United States (US). The emphasis is on data from Lawrence Livermore National Laboratory (LLNL)-managed stations MNA, ELK, KNB and LAC that recorded many nuclear tests and nearby earthquakes in broadband digital form since 1980, along with a small number of earlier events that were digitized from tapes. Through the generous cooperation of Sandia National Laboratory (SNL) we have also included waveforms from their Leo Brady network (BMN, DWN, LDS, NEL,TON). In addition we include data from other open broadband stations in the western US with long operating histories and/or ties to the International Monitoring System (IMS) (e.g. PFO, YKA, CMB, NEW, DUG, ANMO, TUC). These waveforms are associated with a reconciled catalog of events and station response information to facilitate analysis. The goal is to create a high-quality database that can be used in the future to analyze fundamental regional monitoring issues such as detection, location, magnitude, and discrimination. In the first stage of the project, we collected six different regional network catalogs from the University of Nevada, Reno (UNR), to provide accurate independent location information for events on the Nevada Test Site (NTS) and in the surrounding region. We have used National Nuclear Security Administration (NNSA)-developed software to reconcile these catalogs with each other and to incorporate them into a set of larger continental scale (CNSS, see http://www.cnss.org; USGS mining catalog compiled by Jim Dewey) and global scale (PDE, REB, ISC) catalogs. Finally, we incorporate the best catalogs of NTS nuclear event locations and source properties (Springer et al. 2002). The result is a single catalog of preferred origins, source information, and station information. Concurrently, we collected continuous seismic data from open stations and

  2. Advances in mechanistic understanding of release rate control mechanisms of extended-release hydrophilic matrix tablets.

    PubMed

    Timmins, Peter; Desai, Divyakant; Chen, Wei; Wray, Patrick; Brown, Jonathan; Hanley, Sarah

    2016-08-01

    Approaches to characterizing and developing understanding around the mechanisms that control the release of drugs from hydrophilic matrix tablets are reviewed. While historical context is provided and direct physical characterization methods are described, recent advances including the role of percolation thresholds, the application on magnetic resonance and other spectroscopic imaging techniques are considered. The influence of polymer and dosage form characteristics are reviewed. The utility of mathematical modeling is described. Finally, how all the information derived from applying the developed mechanistic understanding from all of these tools can be brought together to develop a robust and reliable hydrophilic matrix extended-release tablet formulation is proposed. PMID:27444495

  3. Understanding small biomolecule-biomaterial interactions: a review of fundamental theoretical and experimental approaches for biomolecule interactions with inorganic surfaces.

    PubMed

    Costa, Dominique; Garrain, Pierre-Alain; Baaden, Marc

    2013-04-01

    Interactions between biomolecules and inorganic surfaces play an important role in natural environments and in industry, including a wide variety of conditions: marine environment, ship hulls (fouling), water treatment, heat exchange, membrane separation, soils, mineral particles at the earth's surface, hospitals (hygiene), art and buildings (degradation and biocorrosion), paper industry (fouling) and more. To better control the first steps leading to adsorption of a biomolecule on an inorganic surface, it is mandatory to understand the adsorption mechanisms of biomolecules of several sizes at the atomic scale, that is, the nature of the chemical interaction between the biomolecule and the surface and the resulting biomolecule conformations once adsorbed at the surface. This remains a challenging and unsolved problem. Here, we review the state of art in experimental and theoretical approaches. We focus on metallic biomaterial surfaces such as TiO(2) and stainless steel, mentioning some remarkable results on hydroxyapatite. Experimental techniques include atomic force microscopy, surface plasmon resonance, quartz crystal microbalance, X-ray photoelectron spectroscopy, fluorescence microscopy, polarization modulation infrared reflection absorption spectroscopy, sum frequency generation and time of flight secondary ion mass spectroscopy. Theoretical models range from detailed quantum mechanical representations to classical forcefield-based approaches. PMID:23015529

  4. Advanced Model Compounds for Understanding Acid-Catalyzed Lignin Depolymerization: Identification of Renewable Aromatics and a Lignin-Derived Solvent.

    PubMed

    Lahive, Ciaran W; Deuss, Peter J; Lancefield, Christopher S; Sun, Zhuohua; Cordes, David B; Young, Claire M; Tran, Fanny; Slawin, Alexandra M Z; de Vries, Johannes G; Kamer, Paul C J; Westwood, Nicholas J; Barta, Katalin

    2016-07-20

    The development of fundamentally new approaches for lignin depolymerization is challenged by the complexity of this aromatic biopolymer. While overly simplified model compounds often lack relevance to the chemistry of lignin, the direct use of lignin streams poses significant analytical challenges to methodology development. Ideally, new methods should be tested on model compounds that are complex enough to mirror the structural diversity in lignin but still of sufficiently low molecular weight to enable facile analysis. In this contribution, we present a new class of advanced (β-O-4)-(β-5) dilinkage models that are highly realistic representations of a lignin fragment. Together with selected β-O-4, β-5, and β-β structures, these compounds provide a detailed understanding of the reactivity of various types of lignin linkages in acid catalysis in conjunction with stabilization of reactive intermediates using ethylene glycol. The use of these new models has allowed for identification of novel reaction pathways and intermediates and led to the characterization of new dimeric products in subsequent lignin depolymerization studies. The excellent correlation between model and lignin experiments highlights the relevance of this new class of model compounds for broader use in catalysis studies. Only by understanding the reactivity of the linkages in lignin at this level of detail can fully optimized lignin depolymerization strategies be developed. PMID:27310182

  5. COLLABORATIVE RESEARCH: TOWARDS ADVANCED UNDERSTANDING AND PREDICTIVE CAPABILITY OF CLIMATE CHANGE IN THE ARCTIC USING A HIGH-RESOLUTION REGIONAL ARCTIC CLIMATE SYSTEM MODEL

    SciTech Connect

    Gutowski, William J.

    2013-02-07

    The motivation for this project was to advance the science of climate change and prediction in the Arctic region. Its primary goals were to (i) develop a state-of-the-art Regional Arctic Climate system Model (RACM) including high-resolution atmosphere, land, ocean, sea ice and land hydrology components and (ii) to perform extended numerical experiments using high performance computers to minimize uncertainties and fundamentally improve current predictions of climate change in the northern polar regions. These goals were realized first through evaluation studies of climate system components via one-way coupling experiments. Simulations were then used to examine the effects of advancements in climate component systems on their representation of main physics, time-mean fields and to understand variability signals at scales over many years. As such this research directly addressed some of the major science objectives of the BER Climate Change Research Division (CCRD) regarding the advancement of long-term climate prediction.

  6. Fundamental Science for Geologic Carbon Sequestration: Molecular Probes for Understanding Wet CO2 Interaction with Caprock Minerals (Invited)

    NASA Astrophysics Data System (ADS)

    Rosso, K. M.; White, D.; Murphy, E. M.; Hu, J.; Hoyt, D. W.; Wang, Z.; Lea, A. S.; Schaef, H. T.; McGrail, P.

    2009-12-01

    in situ. Collectively, this set of capabilities provides a unique platform for elucidating the role of water for catalyzing mineral transformation to metal carbonates and provides a means for determining effective kinetic constants. Understanding and accurately representing chemical mechanisms will be critical for improving reactive transport reservoir simulations to the point that mineralization of CO2 to carbonates can ultimately be predicted in structurally complex and heterogeneous subsurface systems.

  7. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

  8. Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches.

    PubMed

    Snyder, Hannah R; Miyake, Akira; Hankin, Benjamin L

    2015-01-01

    Executive function (EF) is essential for successfully navigating nearly all of our daily activities. Of critical importance for clinical psychological science, EF impairments are associated with most forms of psychopathology. However, despite the proliferation of research on EF in clinical populations, with notable exceptions clinical and cognitive approaches to EF have remained largely independent, leading to failures to apply theoretical and methodological advances in one field to the other field and hindering progress. First, we review the current state of knowledge of EF impairments associated with psychopathology and limitations to the previous research in light of recent advances in understanding and measuring EF. Next, we offer concrete suggestions for improving EF assessment. Last, we suggest future directions, including integrating modern models of EF with state of the art, hierarchical models of dimensional psychopathology as well as translational implications of EF-informed research on clinical science. PMID:25859234

  9. Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches

    PubMed Central

    Snyder, Hannah R.; Miyake, Akira; Hankin, Benjamin L.

    2015-01-01

    Executive function (EF) is essential for successfully navigating nearly all of our daily activities. Of critical importance for clinical psychological science, EF impairments are associated with most forms of psychopathology. However, despite the proliferation of research on EF in clinical populations, with notable exceptions clinical and cognitive approaches to EF have remained largely independent, leading to failures to apply theoretical and methodological advances in one field to the other field and hindering progress. First, we review the current state of knowledge of EF impairments associated with psychopathology and limitations to the previous research in light of recent advances in understanding and measuring EF. Next, we offer concrete suggestions for improving EF assessment. Last, we suggest future directions, including integrating modern models of EF with state of the art, hierarchical models of dimensional psychopathology as well as translational implications of EF-informed research on clinical science. PMID:25859234

  10. Advances in the understanding of host response associated with tumor PDT

    NASA Astrophysics Data System (ADS)

    Korbelik, Mladen

    2007-02-01

    Photodynamic therapy (PDT) is clinically established modality used for treatment of solid cancers and other conditions, which destroys lesions by localized generation of cytotoxic oxygen species mediated by administered drugs (photosensitizers) that are activated at targeted sites by exposure to light. Since over 20 years ago it has become increasingly clear that important contribution to the antitumor effect of PDT is secured by host reaction induced by this therapy and manifested as inflammatory and immune response. Presented is an overview of advances in the understanding of this host response associated with tumor PDT by tracing its evolution from initial breakthroughs and discoveries in the early 1980s, followed by advances preceding recent developments, and concluding with recently acquired knowledge and directions for clinical exploitation. Tribute is given to researchers making important contributions to this field during the last three decades including Drs. Gianfranco Canti, Julia Levy, and Barbara Henderson.

  11. Advances in the understanding of dairy and cheese flavors: symposium introduction.

    PubMed

    Tunick, Michael H; Gummalla, Sanjay

    2014-06-25

    A symposium titled "Advances in the Understanding of Dairy and Cheese Flavors" was held in September 2013 at the American Chemical Society's 246th National Meeting in Indianapolis, IN, USA. The symposium, which was sponsored by the Division of Agricultural and Food Chemistry, was to discuss the state of the art in the detection and quantitation of flavor in dairy products. The authors of two of the presentations have been selected to expand on their talks by submitting full papers about their research. PMID:24911867

  12. Beyond Homophily: A Decade of Advances in Understanding Peer Influence Processes

    PubMed Central

    Brechwald, Whitney A.; Prinstein, Mitchell J.

    2013-01-01

    This article reviews empirical and theoretical contributions to a multidisciplinary understanding of peer influence processes in adolescence over the past decade. Five themes of peer influence research from this decade were identified, including a broadening of the range of behaviors for which peer influence occurs, distinguishing the sources of influence, probing the conditions under which influence is amplified/attenuated (moderators), testing theoretically based models of peer influence processes (mechanisms), and preliminary exploration of behavioral neuroscience perspectives on peer influence. This review highlights advances in each of these areas, underscores gaps in current knowledge of peer influence processes, and outlines important challenges for future research. PMID:23730122

  13. USE OF COUPLED MULTI-ELECTRODE ARRAYS TO ADVANCE THE UNDERSTANDING OF SELECTED CORROSION PHENOMENA

    SciTech Connect

    N.D. Budiansky; F. Bocher; H. Cong; M.F. Hurley; J.R. Scully

    2006-02-23

    The use of multi-coupled electrode arrays in various corrosion applications is discussed with the main goal of advancing the understanding of various corrosion phenomena. Both close packed and far spaced electrode configurations are discussed. Far spaced electrode arrays are optimized for high throughput experiments capable of elucidating the effects of various variables on corrosion properties. For instance the effects of a statistical distribution of flaws on corrosion properties can be examined. Close packed arrays enable unprecedented spatial and temporal information on the behavior of local anodes and cathodes. Interactions between corrosion sites can trigger or inhibit corrosion phenomena and affect corrosion damage evolution.

  14. a Roadmap to Advance Understanding of the Science of Space Weather

    NASA Astrophysics Data System (ADS)

    Schrijver, K.; Kauristie, K.; Aylward, A.; De Nardin, C. M.; Gibson, S. E.; Glover, A.; Gopalswamy, N.; Grande, M.; Hapgood, M. A.; Heynderickx, D.; Jakowski, N.; Kalegaev, V. V.; Lapenta, G.; Linker, J.; Liu, S.; Mandrini, C. H.; Mann, I. R.; Nagatsuma, T.; Nandy, D.; Obara, T.; O'Brien, T. P., III; Onsager, T. G.; Opgenoorth, H. J.; Terkildsen, M. B.; Valladares, C. E.; Vilmer, N.

    2015-12-01

    There is a growing appreciation that the environmental conditions that we call space weather impact the technological infrastructure that powers the coupled economies around the world. With that comes the need to better shield society against space weather by improving forecasts, environmental specifications, and infrastructure design. A COSPAR/ILWS team recently completed a roadmap that identifies the scientific focus areas and research infrastructure that are needed to significantly advance our understanding of space weather of all intensities and of its implications and costs for society. This presentation provides a summary of the highest-priority recommendations from that roadmap.

  15. Advances in understanding itching and scratching: a new era of targeted treatments.

    PubMed

    Sanders, Kristen M; Nattkemper, Leigh A; Yosipovitch, Gil

    2016-01-01

    Chronic itch is a significant health burden with few effective treatments. As such, itch researchers seek to understand the mechanisms behind itch and to find potential targets for treatment. The field of itch research is dynamic, and many advances have been made so far this decade. In particular, major steps forward include the identification of new peripheral and central itch mediators and modulators, the discovery of greater roles for immune cells and glia in itch transmission, and a focus on the brain processing of itching and scratching. Finally, several new therapeutic interventions for itch have shown success in clinical trials. PMID:27610225

  16. Advances in understanding itching and scratching: a new era of targeted treatments

    PubMed Central

    Sanders, Kristen M.; Nattkemper, Leigh A.; Yosipovitch, Gil

    2016-01-01

    Chronic itch is a significant health burden with few effective treatments. As such, itch researchers seek to understand the mechanisms behind itch and to find potential targets for treatment. The field of itch research is dynamic, and many advances have been made so far this decade. In particular, major steps forward include the identification of new peripheral and central itch mediators and modulators, the discovery of greater roles for immune cells and glia in itch transmission, and a focus on the brain processing of itching and scratching. Finally, several new therapeutic interventions for itch have shown success in clinical trials. PMID:27610225

  17. Advances in the theoretical understanding of photon upconversion in rare-earth activated nanophosphors.

    PubMed

    Liu, Guokui

    2015-03-21

    Photon upconversion in rare earth activated phosphors involves multiple mechanisms of electronic transitions. Stepwise optical excitation, energy transfer, and various nonlinear and collective light-matter interaction processes act together to convert low-energy photons into short-wavelength light emission. Upconversion luminescence from nanomaterials exhibits additional size and surface dependencies. A fundamental understanding of the overall performance of an upconversion system requires basic theories on the spectroscopic properties of solids containing rare earth ions. This review article surveys the recent progress in the theoretical interpretations of the spectroscopic characteristics and luminescence dynamics of photon upconversion in rare earth activated phosphors. The primary aspects of upconversion processes, including energy level splitting, transition probability, line broadening, non-radiative relaxation and energy transfer, are covered with an emphasis on interpreting experimental observations. Theoretical models and methods for analyzing nano-phenomena in upconversion are introduced with detailed discussions on recently reported experimental results. PMID:25286989

  18. Advances in understanding monoclonal gammopathy of undetermined significance as a precursor of multiple myeloma

    PubMed Central

    Weiss, Brendan M; Kuehl, W Michael

    2010-01-01

    Monoclonal gammopathy of undetermined significance (MGUS) affects at least 3% of the population above the age of 50 and is the precursor to multiple myeloma (MM), an incurable malignancy of plasma cells. Recent advances in MGUS include: an improved understanding of the pathogenesis of MGUS and its progression to MM, involving molecular events intrinsic to the malignant plasma cell as well as the microenvironment; novel techniques to assess risk for progression to MM using serum-free light-chain analysis and immunophenotyping; and a renewed interest in chemoprevention of MM. In the future, continued improvement in our understanding of MGUS will lead to the development of better biomarkers for prognosis and therapies for chemoprevention of MM. PMID:20473362

  19. Advances in understanding and treating liver diseases during pregnancy: A review

    PubMed Central

    Kamimura, Kenya; Abe, Hiroyuki; Kawai, Hirokazu; Kamimura, Hiroteru; Kobayashi, Yuji; Nomoto, Minoru; Aoyagi, Yutaka; Terai, Shuji

    2015-01-01

    Liver disease in pregnancy is rare but pregnancy-related liver diseases may cause threat to fetal and maternal survival. It includes pre-eclampsia; eclampsia; haemolysis, elevated liver enzymes, and low platelets syndrome; acute fatty liver of pregnancy; hyperemesis gravidarum; and intrahepatic cholestasis of pregnancy. Recent basic researches have shown the various etiologies involved in this disease entity. With these advances, rapid diagnosis is essential for severe cases since the decision of immediate delivery is important for maternal and fetal survival. The other therapeutic options have also been shown in recent reports based on the clinical trials and cooperation and information sharing between hepatologist and gynecologist is important for timely therapeutic intervention. Therefore, correct understandings of diseases and differential diagnosis from the pre-existing and co-incidental liver diseases during the pregnancy will help to achieve better prognosis. Therefore, here we review and summarized recent advances in understanding the etiologies, clinical courses and management of liver disease in pregnancy. This information will contribute to physicians for diagnosis of disease and optimum management of patients. PMID:25954092

  20. Advances in Understanding of Swift Heavy-Ion Tracks in Complex Ceramics

    SciTech Connect

    Lang, Maik; Devanathan, Ram; Toulemonde, Marcel; Trautmann, Christina

    2015-02-01

    Tracks produced by swift heavy ions in ceramics are of interest for fundamental science as well as for applications covering different fields such as nanotechnology or fission-track dating of minerals. In the case of pyrochlores with general formula A2B2O7, the track structure and radiation sensitivity shows a clear dependence on the composition. Ion irradiated Gd2Zr2O7, e.g., retains its crystallinity while amorphous tracks are produced in Gd2Ti2O7. Tracks in Ti-containing compositions have a complex morphology consisting of an amorphous core surrounded by a shell of a disordered, defect-fluorite phase. The size of the amorphous core decreases with decreasing energy loss and with increasing Zr content, while the shell thickness seems to be similar over a wide range of energy loss values. The large data set and the complex track structure has made pyrochlore an interesting model system for a general theoretical description of track formation including thermal spike calculations (providing the spatial and temporal evolution of temperature around the ion trajectory) and molecular dynamics (MD) simulations (describing the response of the atomic system).Recent MD advances consider the sudden temperature increase by inserting data from the thermal spike. The combination allows the reproduction of the core-shell track characteristic and sheds light on the early stages of track formation including recrystallization of the molten material produced by the thermal spike.

  1. Advancing our understanding of functional genome organisation through studies in the fission yeast

    PubMed Central

    Olsson, Ida

    2010-01-01

    Significant progress has been made in understanding the functional organisation of the cell nucleus. Still many questions remain to be answered about the relationship between the spatial organisation of the nucleus and the regulation of the genome function. There are many conflicting data in the field making it very difficult to merge published results on mammalian cells into one model on subnuclear chromatin organisation. The fission yeast, Schizosaccharomyces pombe, over the last decades has emerged as a valuable model organism in understanding basic biological mechanisms, especially the cell cycle and chromosome biology. In this review we describe and compare the nuclear organisation in mammalian and fission yeast cells. We believe that fission yeast is a good tool to resolve at least some of the contradictions and unanswered questions concerning functional nuclear architecture, since S. pombe has chromosomes structurally similar to that of human. S. pombe also has the advantage over higher eukaryotes in that the genome can easily be manipulated via homologous recombination making it possible to integrate the tools needed for visualisation of chromosomes using live-cell microscopy. Classical genetic experiments can be used to elucidate what factors are involved in a certain mechanism. The knowledge we have gained during the last few years indicates similarities between the genome organisation in fission yeast and mammalian cells. We therefore propose the use of fission yeast for further advancement of our understanding of functional nuclear organisation. PMID:21113595

  2. Advances in understanding the molecular basis of the first steps in color vision.

    PubMed

    Hofmann, Lukas; Palczewski, Krzysztof

    2015-11-01

    Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis-trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation. PMID:26187035

  3. Advancing understanding of microbial bioenergy conversion processes by activity-based protein profiling

    SciTech Connect

    Liu, Yun; Fredrickson, James K.; Sadler, Natalie C.; Nandhikonda, Premchendar; Smith, Richard D.; Wright, Aaron T.

    2015-09-25

    Here, the development of renewable biofuels is a global priority, but success will require novel technologies that greatly improve our understanding of microbial systems biology. An approach with great promise in enabling functional characterization of microbes is activity-based protein profiling (ABPP), which employs chemical probes to directly measure enzyme function in discrete enzyme classes in vivo and/or in vitro, thereby facilitating the rapid discovery of new biocatalysts and enabling much improved biofuel production platforms. We review general design strategies in ABPP, and highlight recent advances that are or could be pivotal to biofuels processes including applications of ABPP to cellulosic bioethanol, biodiesel, and phototrophic production of hydrocarbons. We also examine the key challenges and opportunities of ABPP in renewable biofuels research. The integration of ABPP with molecular and systems biology approaches will shed new insight on the catalytic and regulatory mechanisms of functional enzymes and their synergistic effects in the field of biofuels production.

  4. Advances in understanding the mechanisms of erythropoiesis in homeostasis and disease.

    PubMed

    Liang, Raymond; Ghaffari, Saghi

    2016-09-01

    Anaemia or decreased blood haemoglobin is the most common blood disorder often characterized by reduced red blood cell (RBC) numbers. RBCs are produced from differentiation and commitment of haematopoietic stem cells to the erythroid lineage by a process called erythropoiesis. Coordination of erythropoietin receptor signalling with several erythroid transcription factors including GATA1 is essential for this process. A number of additional players that are critical for RBC production have been identified in recent years. Major technological advances, such as the development of RNA interference, genetically modified animals, including zebrafish, and imaging flow cytometry have led to these discoveries; the emergence of -omics approaches in combination with the optimization of ex vivo erythroid cultures have also produced a more comprehensive understanding of erythropoiesis. Here we summarize studies describing novel regulators of erythropoiesis that modulate erythroid cell production in the context of human erythroid disorders involving hypoxia, iron regulation, immune-related molecules, and the transcription factor FOXO3. PMID:27442953

  5. Advances in understanding the molecular basis of the first steps in color vision

    PubMed Central

    Hofmann, Lukas; Palczewski, Krzysztof

    2015-01-01

    Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis–trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation. PMID:26187035

  6. Advances and limits of using population genetics to understand local adaptation.

    PubMed

    Tiffin, Peter; Ross-Ibarra, Jeffrey

    2014-12-01

    Local adaptation shapes species diversity, can be a stepping stone to ecological speciation, and can facilitate species range expansion. Population genetic analyses, which complement organismal approaches in advancing our understanding of local adaptation, have become widespread in recent years. We focus here on using population genetics to address some key questions in local adaptation: what traits are involved? What environmental variables are the most important? Does local adaptation target the same genes in related species? Do loci responsible for local adaptation exhibit trade-offs across environments? After discussing these questions we highlight important limitations to population genetic analyses including challenges with obtaining high-quality data, deciding which loci are targets of selection, and limits to identifying the genetic basis of local adaptation. PMID:25454508

  7. Recent scientific advances in leiomyoma (uterine fibroids) research facilitates better understanding and management.

    PubMed

    Taylor, Darlene K; Holthouser, Kristine; Segars, James H; Leppert, Phyllis C

    2015-01-01

    Uterine leiomyomas (fibroids) are the most prevalent medical problem of the female reproductive tract, but there are few non-surgical treatment options. Although many advances in the understanding of the molecular components of these tumors have occurred over the past five years, an effective pharmaceutical approach remains elusive. Further, there is currently no clinical method to distinguish a benign uterine leiomyoma from a malignant leiomyosarcoma prior to treatment, a pressing need given concerns about the use of the power morcellator for minimally invasive surgery. This paper reviews current studies regarding the molecular biology of uterine fibroids, discusses non-surgical approaches and suggests new cutting-edge therapeutic and diagnostic approaches. PMID:26236472

  8. Recent scientific advances in leiomyoma (uterine fibroids) research facilitates better understanding and management

    PubMed Central

    Taylor, Darlene K.; Holthouser, Kristine; Segars, James H.; Leppert, Phyllis C.

    2015-01-01

    Uterine leiomyomas (fibroids) are the most prevalent medical problem of the female reproductive tract, but there are few non-surgical treatment options. Although many advances in the understanding of the molecular components of these tumors have occurred over the past five years, an effective pharmaceutical approach remains elusive. Further, there is currently no clinical method to distinguish a benign uterine leiomyoma from a malignant leiomyosarcoma prior to treatment, a pressing need given concerns about the use of the power morcellator for minimally invasive surgery. This paper reviews current studies regarding the molecular biology of uterine fibroids, discusses non-surgical approaches and suggests new cutting-edge therapeutic and diagnostic approaches. PMID:26236472

  9. Recent advances in understanding the role of the hypothalamic circuit during aggression

    PubMed Central

    Falkner, Annegret L.; Lin, Dayu

    2014-01-01

    The hypothalamus was first implicated in the classic “fight or flight” response nearly a century ago, and since then, many important strides have been made in understanding both the circuitry and the neural dynamics underlying the generation of these behaviors. In this review, we will focus on the role of the hypothalamus in aggression, paying particular attention to recent advances in the field that have allowed for functional identification of relevant hypothalamic subnuclei. Recent progress in this field has been aided by the development of new techniques for functional manipulation including optogenetics and pharmacogenetics, as well as advances in technology used for chronic in vivo recordings during complex social behaviors. We will examine the role of the hypothalamus through the complimentary lenses of (1) loss of function studies, including pharmacology and pharmacogenetics; (2) gain of function studies, including specific comparisons between results from classic electrical stimulation studies and more recent work using optogenetics; and (3) neural activity, including both immediate early gene and awake-behaving recordings. Lastly, we will outline current approaches to identifying the precise role of the hypothalamus in promoting aggressive motivation and aggressive action. PMID:25309351

  10. Advanced MRI techniques to improve our understanding of experience-induced neuroplasticity.

    PubMed

    Tardif, Christine Lucas; Gauthier, Claudine Joëlle; Steele, Christopher John; Bazin, Pierre-Louis; Schäfer, Andreas; Schaefer, Alexander; Turner, Robert; Villringer, Arno

    2016-05-01

    Over the last two decades, numerous human MRI studies of neuroplasticity have shown compelling evidence for extensive and rapid experience-induced brain plasticity in vivo. To date, most of these studies have consisted of simply detecting a difference in structural or functional images with little concern for their lack of biological specificity. Recent reviews and public debates have stressed the need for advanced imaging techniques to gain a better understanding of the nature of these differences - characterizing their extent in time and space, their underlying biological and network dynamics. The purpose of this article is to give an overview of advanced imaging techniques for an audience of cognitive neuroscientists that can assist them in the design and interpretation of future MRI studies of neuroplasticity. The review encompasses MRI methods that probe the morphology, microstructure, function, and connectivity of the brain with improved specificity. We underline the possible physiological underpinnings of these techniques and their recent applications within the framework of learning- and experience-induced plasticity in healthy adults. Finally, we discuss the advantages of a multi-modal approach to gain a more nuanced and comprehensive description of the process of learning. PMID:26318050

  11. Hospital fundamentals.

    PubMed

    Althausen, Peter L; Hill, Austin D; Mead, Lisa

    2014-07-01

    Under the current system, orthopaedic trauma surgeons must work in some form of hospital setting as our primary service involves treatment of the trauma patient. We must not forget that just as a trauma center cannot exist without our services, we cannot function without their support. As a result, a clear understanding of the balance between physicians and hospitals is paramount. Historical perspective enables physicians and hospital personnel alike to understand the evolution of hospital-physician relationship. This process should be understood upon completion of this chapter. The relationship between physicians and hospitals is becoming increasingly complex and multiple forms of integration exist such as joint ventures, gain sharing, and co-management agreements. For the surgeon to negotiate well, an understanding of hospital governance and the role of the orthopaedic traumatologist is vital to success. An understanding of the value provided by the traumatologist includes all aspects of care including efficiency, availability, cost effectiveness, and research activities. To create effective and sustainable healthcare institutions, physicians and hospitals must be aligned over a sustained period of time. Unfortunately, external forces have eroded the historical basis for the working relationship between physicians and hospitals. Increased competition and reimbursement cuts, coupled with the increasing demands for quality, efficiency, and coordination and the payment changes outlined in healthcare reform, have left many organizations wondering how to best rebuild the relationship. The principal goal for the physician when partnering with a hospital or healthcare entity is to establish a sustainable model of service line management that protects or advances the physician's ability to make impactful improvements in quality of patient care, decreases in healthcare costs, and improvements in process efficiency through evidence-based practices and protocols. PMID

  12. ENHANCING THE ATOMIC-LEVEL UNDERSTANDING OF CO2 MINERAL SEQUESTRATION MECHANISMS VIA ADVANCED COMPUTATIONAL MODELING

    SciTech Connect

    A.V.G. Chizmeshya

    2002-12-19

    /NETL managed National Mineral Sequestration Working Group we have already significantly improved our understanding of mineral carbonation. Group members at the Albany Research Center have recently shown that carbonation of olivine and serpentine, which naturally occurs over geological time (i.e., 100,000s of years), can be accelerated to near completion in hours. Further process refinement will require a synergetic science/engineering approach that emphasizes simultaneous investigation of both thermodynamic processes and the detailed microscopic, atomic-level mechanisms that govern carbonation kinetics. Our previously funded Phase I Innovative Concepts project demonstrated the value of advanced quantum-mechanical modeling as a complementary tool in bridging important gaps in our understanding of the atomic/molecular structure and reaction mechanisms that govern CO{sub 2} mineral sequestration reaction processes for the model Mg-rich lamellar hydroxide feedstock material Mg(OH){sub 2}. In the present simulation project, improved techniques and more efficient computational schemes have allowed us to expand and augment these capabilities and explore more complex Mg-rich, lamellar hydroxide-based feedstock materials, including the serpentine-based minerals. These feedstock materials are being actively investigated due to their wide availability, and low-cost CO{sub 2} mineral sequestration potential. Cutting-edge first principles quantum chemical, computational solid-state and materials simulation methodology studies proposed herein, have been strategically integrated with our new DOE supported (ASU-Argonne National Laboratory) project to investigate the mechanisms that govern mineral feedstock heat-treatment and aqueous/fluid-phase serpentine mineral carbonation in situ. This unified, synergetic theoretical and experimental approach will provide a deeper understanding of the key reaction mechanisms than either individual approach can alone. Ab initio techniques will also

  13. ENHANCING THE ATOMIC-LEVEL UNDERSTANDING OF CO2 MINERAL SEQUESTRATION MECHANISMS VIA ADVANCED COMPUTATIONAL MODELING

    SciTech Connect

    A.V.G. Chizmeshya; M.J. McKelvy; G.H. Wolf; R.W. Carpenter; D.A. Gormley; J.R. Diefenbacher; R. Marzke

    2006-03-01

    significantly improved our understanding of mineral carbonation. Group members at the Albany Research Center have recently shown that carbonation of olivine and serpentine, which naturally occurs over geological time (i.e., 100,000s of years), can be accelerated to near completion in hours. Further process refinement will require a synergetic science/engineering approach that emphasizes simultaneous investigation of both thermodynamic processes and the detailed microscopic, atomic-level mechanisms that govern carbonation kinetics. Our previously funded Phase I Innovative Concepts project demonstrated the value of advanced quantum-mechanical modeling as a complementary tool in bridging important gaps in our understanding of the atomic/molecular structure and reaction mechanisms that govern CO2 mineral sequestration reaction processes for the model Mg-rich lamellar hydroxide feedstock material Mg(OH)2. In the present simulation project, improved techniques and more efficient computational schemes have allowed us to expand and augment these capabilities and explore more complex Mg-rich, lamellar hydroxide-based feedstock materials, including the serpentine-based minerals. These feedstock materials are being actively investigated due to their wide availability, and low-cost CO2 mineral sequestration potential. Cutting-edge first principles quantum chemical, computational solid-state and materials simulation methodology studies proposed herein, have been strategically integrated with our new DOE supported (ASU-Argonne National Laboratory) project to investigate the mechanisms that govern mineral feedstock heat-treatment and aqueous/fluid-phase serpentine mineral carbonation in situ. This unified, synergetic theoretical and experimental approach has provided a deeper understanding of the key reaction mechanisms than either individual approach can alone. We used ab initio techniques to significantly advance our understanding of atomic-level processes at the solid/solution interface by

  14. ENHANCING THE ATOMIC-LEVEL UNDERSTANDING OF CO2 MINERAL SEQUESTRATION MECHANISMS VIA ADVANCED COMPUTATIONAL MODELING

    SciTech Connect

    A.V.G. Chizmeshya

    2003-12-19

    /NETL managed National Mineral Sequestration Working Group we have already significantly improved our understanding of mineral carbonation. Group members at the Albany Research Center have recently shown that carbonation of olivine and serpentine, which naturally occurs over geological time (i.e., 100,000s of years), can be accelerated to near completion in hours. Further process refinement will require a synergetic science/engineering approach that emphasizes simultaneous investigation of both thermodynamic processes and the detailed microscopic, atomic-level mechanisms that govern carbonation kinetics. Our previously funded Phase I Innovative Concepts project demonstrated the value of advanced quantum-mechanical modeling as a complementary tool in bridging important gaps in our understanding of the atomic/molecular structure and reaction mechanisms that govern CO{sub 2} mineral sequestration reaction processes for the model Mg-rich lamellar hydroxide feedstock material Mg(OH){sub 2}. In the present simulation project, improved techniques and more efficient computational schemes have allowed us to expand and augment these capabilities and explore more complex Mg-rich, lamellar hydroxide-based feedstock materials, including the serpentine-based minerals. These feedstock materials are being actively investigated due to their wide availability, and low-cost CO{sub 2} mineral sequestration potential. Cutting-edge first principles quantum chemical, computational solid-state and materials simulation methodology studies proposed herein, have been strategically integrated with our new DOE supported (ASU-Argonne National Laboratory) project to investigate the mechanisms that govern mineral feedstock heat-treatment and aqueous/fluid-phase serpentine mineral carbonation in situ. This unified, synergetic theoretical and experimental approach will provide a deeper understanding of the key reaction mechanisms than either individual approach can alone. Ab initio techniques will also

  15. Advances in understanding societal vulnerability to tsunamis in the United States

    NASA Astrophysics Data System (ADS)

    Wood, N. J.

    2009-12-01

    Loss of life and property damage from future tsunamis can be reduced if officials develop risk-reduction strategies and education programs that address how at-risk populations and communities are specifically vulnerable to tsunamis. Prior to the 2004 Indian Ocean tsunami, information concerning societal vulnerability to tsunamis in the U.S. was largely limited to state-level summaries of the number of residents within one kilometer of the coast. Since 2004, the U.S. Geological Survey has furthered the Nation’s understanding of societal vulnerability to tsunamis with several studies that describe the exposure, sensitivity, and adaptive capacity of at-risk populations in tsunami-hazard zones. Community-level assessments have been completed in Hawaii, Oregon, and Washington to document variations in the number and types of people, businesses, and critical facilities in tsunami-prone areas. A method using midresolution satellite imagery was developed to identify community variations in the amount of developed land in tsunami-prone areas. Factor analysis and geospatial analysis were integrated to model variations in demographic sensitivity to tsunamis. Public workshops have been held to examine community sensitivity, adaptive capacity and post-tsunami recovery. Results demonstrate that social vulnerability to tsunamis varies throughout a community or region and that certain areas are likely to suffer disproportionately due to differences in pre-tsunami socioeconomic conditions and other demographic attributes. This presentation will summarize advances in understanding societal vulnerability in the U.S. to tsunamis since the 2004 Indian Ocean tsunami, as well as discuss opportunities and needs for further work.

  16. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estellés, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Rosenberg, P.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Woolley, A.

    2015-01-01

    The Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under

  17. Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

    PubMed Central

    2013-01-01

    Summary The copper-catalyzed azide–alkyne cycloaddition (CuAAC) is one of the most broadly applicable and easy-to-handle reactions in the arsenal of organic chemistry. However, the mechanistic understanding of this reaction has lagged behind the plethora of its applications for a long time. As reagent mixtures of copper salts and additives are commonly used in CuAAC reactions, the structure of the catalytically active species itself has remained subject to speculation, which can be attributed to the multifaceted aggregation chemistry of copper(I) alkyne and acetylide complexes. Following an introductory section on common catalyst systems in CuAAC reactions, this review will highlight experimental and computational studies from early proposals to very recent and more sophisticated investigations, which deliver more detailed insights into the CuAAC’s catalytic cycle and the species involved. As diverging mechanistic views are presented in articles, books and online resources, we intend to present the research efforts in this field during the past decade and finally give an up-to-date picture of the currently accepted dinuclear mechanism of CuAAC. Additionally, we hope to inspire research efforts on the development of molecularly defined copper(I) catalysts with defined structural characteristics, whose main advantage in contrast to the regularly used precatalyst reagent mixtures is twofold: on the one hand, the characteristics of molecularly defined, well soluble catalysts can be tuned according to the particular requirements of the experiment; on the other hand, the understanding of the CuAAC reaction mechanism can be further advanced by kinetic studies and the isolation and characterization of key intermediates. PMID:24367437

  18. Advancements in the mechanistic understanding of the copper-catalyzed azide-alkyne cycloaddition.

    PubMed

    Berg, Regina; Straub, Bernd F

    2013-01-01

    The copper-catalyzed azide-alkyne cycloaddition (CuAAC) is one of the most broadly applicable and easy-to-handle reactions in the arsenal of organic chemistry. However, the mechanistic understanding of this reaction has lagged behind the plethora of its applications for a long time. As reagent mixtures of copper salts and additives are commonly used in CuAAC reactions, the structure of the catalytically active species itself has remained subject to speculation, which can be attributed to the multifaceted aggregation chemistry of copper(I) alkyne and acetylide complexes. Following an introductory section on common catalyst systems in CuAAC reactions, this review will highlight experimental and computational studies from early proposals to very recent and more sophisticated investigations, which deliver more detailed insights into the CuAAC's catalytic cycle and the species involved. As diverging mechanistic views are presented in articles, books and online resources, we intend to present the research efforts in this field during the past decade and finally give an up-to-date picture of the currently accepted dinuclear mechanism of CuAAC. Additionally, we hope to inspire research efforts on the development of molecularly defined copper(I) catalysts with defined structural characteristics, whose main advantage in contrast to the regularly used precatalyst reagent mixtures is twofold: on the one hand, the characteristics of molecularly defined, well soluble catalysts can be tuned according to the particular requirements of the experiment; on the other hand, the understanding of the CuAAC reaction mechanism can be further advanced by kinetic studies and the isolation and characterization of key intermediates. PMID:24367437

  19. Advances in the understanding of cuticular waxes in Arabidopsis thaliana and crop species.

    PubMed

    Lee, Saet Buyl; Suh, Mi Chung

    2015-04-01

    The aerial parts of plants are covered with a cuticle, a hydrophobic layer consisting of cutin polyester and cuticular waxes that protects them from various environmental stresses. Cuticular waxes mainly comprise very long chain fatty acids and their derivatives such as aldehydes, alkanes, secondary alcohols, ketones, primary alcohols, and wax esters that are also important raw materials for the production of lubricants, adhesives, cosmetics, and biofuels. The major function of cuticular waxes is to control non-stomatal water loss and gas exchange. In recent years, the in planta roles of many genes involved in cuticular wax biosynthesis have been characterized not only from model organisms like Arabidopsis thaliana and saltwater cress (Eutrema salsugineum), but also crop plants including maize, rice, wheat, tomato, petunia, Medicago sativa, Medicago truncatula, rapeseed, and Camelina sativa through genetic, biochemical, molecular, genomic, and cell biological approaches. In this review, we discuss recent advances in the understanding of the biological functions of genes involved in cuticular wax biosynthesis, transport, and regulation of wax deposition from Arabidopsis and crop species, provide information on cuticular wax amounts and composition in various organs of nine representative plant species, and suggest the important issues that need to be investigated in this field of study. PMID:25693495

  20. Advancing understanding of microbial bioenergy conversion processes by activity-based protein profiling

    DOE PAGESBeta

    Liu, Yun; Fredrickson, James K.; Sadler, Natalie C.; Nandhikonda, Premchendar; Smith, Richard D.; Wright, Aaron T.

    2015-09-25

    Here, the development of renewable biofuels is a global priority, but success will require novel technologies that greatly improve our understanding of microbial systems biology. An approach with great promise in enabling functional characterization of microbes is activity-based protein profiling (ABPP), which employs chemical probes to directly measure enzyme function in discrete enzyme classes in vivo and/or in vitro, thereby facilitating the rapid discovery of new biocatalysts and enabling much improved biofuel production platforms. We review general design strategies in ABPP, and highlight recent advances that are or could be pivotal to biofuels processes including applications of ABPP to cellulosicmore » bioethanol, biodiesel, and phototrophic production of hydrocarbons. We also examine the key challenges and opportunities of ABPP in renewable biofuels research. The integration of ABPP with molecular and systems biology approaches will shed new insight on the catalytic and regulatory mechanisms of functional enzymes and their synergistic effects in the field of biofuels production.« less

  1. Recent advances in the understanding of Quaternary periglacial features of the English Channel coastlands

    NASA Astrophysics Data System (ADS)

    Murton, Julian B.; Lautridou, Jean-Pierre

    2003-02-01

    Recent advances in the understanding of Quaternary periglaciation of the English Channel coastlands concern laboratory modelling of periglacial processes, dating of periglacial sediments and the distribution of permafrost during marine oxygen isotope stage (MOIS) 2. Modelling studies have successfully simulated (i) ice segregation in chalk in artificial permafrost, (ii) periglacial solifluction of natural slope sediments, and (iii) soft-sediment deformation during thaw of ice-rich soil. The resultant structures and deposits in these experiments have similarities with naturally brecciated chalk, solifluction deposits and involutions, respectively, along the English Channel coastlands, providing insights into their genesis and palaeoenvironmental significance.Dating of periglacial sediments is based on radiocarbon assays of organic material in head deposits, luminescence measurements of loess and coversand, and mammalian biostratigraphy in raised-beach and associated slope deposits. Most age estimates fall within MOIS 2, although some are within MOIS 6 and possibly other cold stages.Maps reconstructing the distribution of permafrost during MOIS 2 vary in detail. The precise distribution of permafrost remains to be established owing to problems of (i) imprecise dating in the context of climatic instability, (ii) uncertain palaeoclimatic significance of particular periglacial structures and (iii) sparse data on the age and distribution of relict periglacial features.The wider significance of periglacial processes to the evolution of the Channel coastlands is speculated to involve rapid valley development by flowing water in areas of moist, frost-susceptible bedrock that has been brecciated by ice segregation.

  2. Understanding Brain Injury and Neurodevelopmental Disabilities in the Preterm Infant: The Evolving Role of Advanced MRI

    PubMed Central

    Mathur, Amit M.; Neil, Jeffrey J.; Inder, Terrie E.

    2010-01-01

    The high incidence of neurodevelopmental disability in premature infants requires continued efforts at understanding the underlying microstructural changes in the brain that cause this perturbation in normal development. Magnetic resonance imaging (MRI) methods offer great potential to fulfill this need. Serial MR imaging and the application of newer analysis techniques such as, diffusion tensor imaging (DTI), volumetric MR analysis, cortical surface analysis, functional connectivity (fcMRI) and diffusion tractography, provide important insights into the trajectory of brain development in the premature infant and the impact of injury on this developmental trajectory. While some of these imaging techniques are currently available in the research setting only, other measures such as DTI and brain metric measures can be used clinically. MR imaging also has enormous potential to be used as a surrogate, short-term outcome measure in clinical studies evaluating new therapeutic interventions of neuroprotection of the developing brain. In this article we review the current status of these advanced MR imaging techniques. PMID:20109973

  3. Oculopharyngeal muscular dystrophy: recent advances in the understanding of the molecular pathogenic mechanisms and treatment strategies.

    PubMed

    Abu-Baker, Aida; Rouleau, Guy A

    2007-02-01

    Oculopharyngeal muscular dystrophy (OPMD) is an adult-onset disorder characterized by progressive eyelid drooping, swallowing difficulties and proximal limb weakness. OPMD is caused by a small expansion of a short polyalanine tract in the poly (A) binding protein nuclear 1 protein (PABPN1). The mechanism by which the polyalanine expansion mutation in PABPN1 causes disease is unclear. PABPN1 is a nuclear multi-functional protein which is involved in pre-mRNA polyadenylation, transcription regulation, and mRNA nucleocytoplasmic transport. The distinct pathological hallmark of OPMD is the presence of filamentous intranuclear inclusions (INIs) in patient's skeletal muscle cells. The exact relationship between mutant PABPN1 intranuclear aggregates and pathology is not clear. OPMD is a unique disease sharing common pathogenic features with other polyalanine disorders, as well as with polyglutamine and dystrophic disorders. This chapter aims to review the rapidly growing body of knowledge concerning OPMD. First, we outline the background of OPMD. Second, we compare OPMD with other trinucleotide repeat disorders. Third, we discuss the recent advances in the understanding of the molecular mechanisms underlying OPMD pathogenesis. Finally, we review recent therapeutic strategies for OPMD. PMID:17110089

  4. Bovine viral diarrhea virus infections: manifestations of infection and recent advances in understanding pathogenesis and control.

    PubMed

    Brodersen, B W

    2014-03-01

    Bovine viral diarrhea virus (BVDV) continues to be of economic significance to the livestock industry in terms of acute disease and fetal loss. Many of the lesions relating to BVDV infection have been well described previously. The virus is perpetuated in herds through the presence of calves that are persistently infected. Relationships between various species and biotypes of BVDV and host defenses are increasingly understood. Understanding of the host defense mechanisms of innate immunity and adaptive immunity continues to improve, and the effects of the virus on these immune mechanisms are being used to explain how persistent infection develops. The noncytopathic biotype of BVDV plays the major role in its effects on the host defenses by inhibiting various aspects of the innate immune system and creation of immunotolerance in the fetus during early gestation. Recent advances have allowed for development of affordable test strategies to identify and remove persistently infected animals. With these improved tests and removal strategies, the livestock industry can begin more widespread effective control programs. PMID:24476940

  5. [Recent advances in the understanding and treatment of diffuse large B-cell lymphoma].

    PubMed

    Gergely, Lajos; Illés, Árpád

    2016-07-01

    Diffuse large B-cell lymphoma is the most common type of non-Hodgkin's lymphoma. Using the conventional cyclophosphamide adriablastin vincristin prednisolon polychemotherapy about 50% of the patients were cured. The addition of rituximab to the regimen increased the cure rate to 60%. This is a major improvement, however, further advance is still needed to increase the cure rate. The extensive genetic testing performed recently revealed several important pathognomic mutations as potential targets in this disease. Routine diagnosis of patients now includes the use of (18)Fluor-deoxy-glucose positron emission computer tomography, according to the recent Lugano classification system. With all these data we can better predict the prognosis of patients, and we can select candidates for novel targeted therapies as well. Answering these questions, and utilizing novel therapies possibly will further increase the cure rate in the near future. This paper summarizes current diagnostic and therapeutic approaches and describes recent understanding in the mutations and pathognomic changes resulting in the disease. The authors also summarize the data available on experimental therapies possibly entering clinical pratice in the forthcoming years. Orv. Hetil., 2016, 157(31), 1232-1241. PMID:27476519

  6. Advances in the formation, use and understanding of multi-cellular spheroids

    PubMed Central

    Achilli, Toni-Marie; Meyer, Julia; Morgan, Jeffrey R

    2015-01-01

    Introduction Developing in vitro models for studying cell biology and cell physiology is of great importance to the fields of biotechnology, cancer research, drug discovery, toxicity testing, as well as the emerging fields of tissue engineering and regenerative medicine. Traditional two dimensional (2D) methods of mammalian cell culture have several limitations and it is increasingly recognized that cells grown in a three dimensional (3D) environment more closely represent normal cellular function due to the increased cell-to-cell interactions, and by mimicking the in vivo architecture of natural organs and tissues. Areas Covered In this review, we discuss the methods to form 3D multi-cellular spheroids, the advantages and limitations of these methods, and assays used to characterize the function of spheroids. The use of spheroids has led to many advances in basic cell sciences, including understanding cancer cell interactions, creating models for drug discovery and cancer metastasis, and they are being investigated as basic units for engineering tissue constructs. As so, this review will focus on contributions made to each of these fields using spheroid models. Expert Opinion Multi-cellular spheroids are rich in biological content and mimic better the in vivo environment than 2D cell culture. New technologies to form and analyze spheroids are rapidly increasing their adoption and expanding their applications. PMID:22784238

  7. Recent advances in the understanding of the Aspergillus fumigatus cell wall.

    PubMed

    Lee, Mark J; Sheppard, Donald C

    2016-03-01

    Over the past several decades, research on the synthesis and organization of the cell wall polysaccharides of Aspergillus fumigatus has expanded our knowledge of this important fungal structure. Besides protecting the fungus from environmental stresses and maintaining structural integrity of the organism, the cell wall is also the primary site for interaction with host tissues during infection. Cell wall polysaccharides are important ligands for the recognition of fungi by the innate immune system and they can mediate potent immunomodulatory effects. The synthesis of cell wall polysaccharides is a complicated process that requires coordinated regulation of many biosynthetic and metabolic pathways. Continuous synthesis and remodeling of the polysaccharides of the cell wall is essential for the survival of the fungus during development, reproduction, colonization and invasion. As these polysaccharides are absent from the human host, these biosynthetic pathways are attractive targets for antifungal development. In this review, we present recent advances in our understanding of Aspergillus fumigatus cell wall polysaccharides, including the emerging role of cell wall polysaccharides in the host-pathogen interaction. PMID:26920883

  8. An overview of the fundamentals of the chemistry of silica with relevance to biosilicification and technological advances.

    PubMed

    Belton, David J; Deschaume, Olivier; Perry, Carole C

    2012-05-01

    Biomineral formation is widespread in nature, and occurs in bacteria, single-celled protists, plants, invertebrates, and vertebrates. Minerals formed in the biological environment often show unusual physical properties (e.g. strength, degree of hydration) and often have structures that exhibit order on many length scales. Biosilica, found in single-celled organisms through to higher plants and primitive animals (sponges), is formed from an environment that is undersaturated with respect to silicon, and under conditions of approximately neutral pH and relatively low temperatures of 4-40 °C compared to those used industrially. Formation of the mineral may occur intracellularly or extracellularly, and specific biochemical locations for mineral deposition that include lipids, proteins and carbohydrates are known. In most cases, the formation of the mineral phase is linked to cellular processes, an understanding of which could lead to the design of new materials for biomedical, optical and other applications. In this contribution, we describe the aqueous chemistry of silica, from uncondensed monomers through to colloidal particles and 3D structures, that is relevant to the environment from which the biomineral forms. We then describe the chemistry of silica formation from alkoxides such as tetraethoxysilane, as this and other silanes have been used to study the chemistry of silica formation using silicatein, and such precursors are often used in the preparation of silicas for technological applications. The focus of this article is on the methods, experimental and computational, by which the process of silica formation can be studied, with an emphasis on speciation. PMID:22333209

  9. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Rosenberg, P. D.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estelles, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Trembath, J.; Woolley, A.

    2015-07-01

    The Fennec climate programme aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE (Service des Avions Français Instrumentés pour la Recherche en Environnement) Falcon 20 is described, with specific focus on instrumentation specially developed for and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include (1) the first airborne measurement of dust particles sizes of up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI (Spinning Enhanced Visible Infra-Red Imager) satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in situ observations of processes in SABL clouds showing dust acting as cloud condensation nuclei (CCN) and ice nuclei (IN) at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold pool (haboob) issued from deep convection over the Atlas Mountains, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area

  10. The NEDICES Study: Recent Advances in the Understanding of the Epidemiology of Essential Tremor

    PubMed Central

    Romero, Juan Pablo; Benito-León, Julián; Bermejo-Pareja, Félix

    2012-01-01

    Background Essential tremor (ET) is the most common tremor disorder. ET has classically been viewed as a benign monosymptomatic condition. Yet over the past 10 years, a growing body of evidence indicates that this is a progressive condition that is clinically heterogeneous, and may be associated with a variety of different features. Large epidemiological studies such as the Neurological Disorders of Central Spain (NEDICES), a longitudinal, population-based survey, have contributed significantly to the changing view of the disease. Our aim is to review some of the main results of NEDICES within the larger framework of the epidemiology of ET. Methods Data for this review were gathered from all our articles published up to October 2011 regarding NEDICES study and “Essential Tremor”. Results We have published 18 articles up to October 2011. The prevalence, incidence, and mortality of ET were analyzed in this cohort. In addition, ET was found to be associated with increased frailty and low morale, as well as with a series of non-motor manifestations, including cognitive deficits, mild cognitive impairment, dementia, depressive symptoms, and hearing impairment. Finally, the link between ET and Parkinson's disease (PD) was formally quantified in the NEDICES study, which demonstrated that the risk of developing incident PD was 4.3 times higher in prevalent ET cases than in age-matched controls without ET. Conclusions This review highlights the contributions of NEDICES towards the advancement of current knowledge of the epidemiology and clinical features of ET, and emphasizes the importance of population-based studies towards the understanding of complex, ageing-related diseases. PMID:23439396

  11. Advances in Understanding Top-of-Atmosphere Radiation Variability from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Loeb, Norman G.; Kato, Seiji; Su, Wenying; Wong, Takmeng; Rose, Fred G.; Doelling, David R.; Norris, Joel R.; Huang, Xianglei

    2012-07-01

    This paper highlights how the emerging record of satellite observations from the Earth Observation System (EOS) and A-Train constellation are advancing our ability to more completely document and understand the underlying processes associated with variations in the Earth's top-of-atmosphere (TOA) radiation budget. Large-scale TOA radiation changes during the past decade are observed to be within 0.5 Wm-2 per decade based upon comparisons between Clouds and the Earth's Radiant Energy System (CERES) instruments aboard Terra and Aqua and other instruments. Tropical variations in emitted outgoing longwave (LW) radiation are found to closely track changes in the El Niño-Southern Oscillation (ENSO). During positive ENSO phase (El Niño), outgoing LW radiation increases, and decreases during the negative ENSO phase (La Niña). The coldest year during the last decade occurred in 2008, during which strong La Nina conditions persisted throughout most of the year. Atmospheric Infrared Sounder (AIRS) observations show that the lower temperatures extended throughout much of the troposphere for several months, resulting in a reduction in outgoing LW radiation and an increase in net incoming radiation. At the global scale, outgoing LW flux anomalies are partially compensated for by decreases in midlatitude cloud fraction and cloud height, as observed by Moderate Resolution Imaging Spectrometer and Multi-angle Imaging SpectroRadiometer, respectively. CERES data show that clouds have a net radiative warming influence during La Niña conditions and a net cooling influence during El Niño, but the magnitude of the anomalies varies greatly from one ENSO event to another. Regional cloud-radiation variations among several Terra and A-Train instruments show consistent patterns and exhibit marked fluctuations at monthly timescales in response to tropical atmosphere-ocean dynamical processes associated with ENSO and Madden-Julian Oscillation.

  12. Experimental alluvial fans: Advances in understanding of fan dynamics and processes

    NASA Astrophysics Data System (ADS)

    Clarke, Lucy E.

    2015-09-01

    Alluvial fans are depositional systems that develop because of a disparity between the upstream and downstream sediment transport capacity of a system, usually at the base of mountain fronts as rivers emerge from the constrained mountain area onto the plain. They are dynamic landforms that are prone to abrupt changes on a geomorphological (decades to centuries) time scale, while also being long-term deposition features that preserve sedimentary strata and are sensitive indictors of environmental change. The complexity of interactions between catchment characteristics, climate, tectonics, internal system feedbacks, and environmental processes on field alluvial fans means that it is difficult to isolate individual variables in a field setting; therefore, the controlled conditions afforded by experimental models has provided a novel technique to overcome some of these complexities. The use of experimental models of alluvial fans has a long history and these have been implemented over a range of different research areas utilising various experimental designs. Using this technique, important advances have been made in determining the primary factors influencing fan slope, understanding of avulsion dynamics, identifying autogenic processes driving change on fan systems independent of any change in external conditions, and the mechanics of flow and flood risk on alluvial fans, to name a few. However, experiments cannot be carried out in isolation. Thus, combining the findings from experimental alluvial fans with field research and numerical modelling is important and, likewise, using these techniques to inform experimental design. If this can be achieved, there is potential for future experimental developments to explore key alluvial fan issues such as stratigraphic preservation potential and simulating extra terrestrial fan systems.

  13. APPLICATION OF ADVANCED IN VITRO TECHNIQUES TO MEASURE, UNDERSTAND AND PREDICT THE KINETICS AND MECHANISMS OF XENOBIOTIC METABOLISM

    EPA Science Inventory

    We have developed a research program in metabolism that involves numerous collaborators across EPA as well as other federal and academic labs. A primary goal is to develop and apply advanced in vitro techniques to measure, understand and predict the kinetics and mechanisms of xen...

  14. Fundamental advancements of the future.

    NASA Technical Reports Server (NTRS)

    Winblade, R. L.

    1972-01-01

    General aviation encompasses all aviation except air carrier and military. This includes a broad spectrum of aircraft types ranging from amateur-built aircraft to jet transports, and includes missions such as transportation of people and freight, firefighting, power line patrol, agricultural, racing, and police patrol. The time span from discovery to broad utilization is such that for the next decade the majority of the innovations that will show up in the general aviation fleet will be derived from today's research efforts. A second area that has high potential is the modification of technology developments for military and transport aircraft to the needs of general aviation requirements of cost, complexity, and reliability.

  15. Understanding of the Dynamics of the Stirling Convertor Advanced by Structural Testing

    NASA Technical Reports Server (NTRS)

    Hughes, William O.

    2003-01-01

    associated harmonics. Therefore, Stirling power systems will not disturb spacecraft science experiments if minimal appropriate mounting efforts are made. The third test program, performed in February and May 2001, resulted in a modal characterization of a Stirling convertor. Since the deflection of the TDC piston rod, under vibration excitation, was of particular interest, the outer pressure shell was removed to allow access to the rod. Through this testing, the Stirling TDC's natural frequencies and modes were identified. This knowledge advanced our understanding of the successful 1999 vibration test and may be utilized to optimize the output power of future Stirling designs. The fourth test program, in April 2001, was conducted to characterize the structural response of a pair of Stirling convertors, as a function of their mounting interface stiffness. The test results provide guidance for the Stirling power package interface design. Properly designed, the interface may lead to increased structural capability and power performance beyond what was demonstrated in the successful 1999 vibration test. Dynamic testing performed to date at Glenn has shown that the Stirling convertors can withstand liftoff random vibration environments and meet "good neighbor" vibratory emission requirements. Furthermore, the future utilization of the information obtained during the tests will allow the corporation selected to be the Stirling system integrator to optimize their convertor and system interfaces designs. Glenn's Thermo-Mechanical Systems Branch provides Stirling technology expertise under a Space Act Agreement with the Department of Energy. Additional vibration testing by Glenn's Structural Systems Dynamics Branch is planned to continue to demonstrate the Stirling power system's vibration capability as its technology and flight system designs progress.

  16. Advanced computational multi-fluid dynamics: a new model for understanding electrokinetic phenomena in porous media

    NASA Astrophysics Data System (ADS)

    Gulamali, M. Y.; Saunders, J. H.; Jackson, M. D.; Pain, C. C.

    2009-04-01

    We present results from a new computational multi-fluid dynamics code, designed to model the transport of heat, mass and chemical species during flow of single or multiple immiscible fluid phases through porous media, including gravitational effects and compressibility. The model also captures the electrical phenomena which may arise through electrokinetic, electrochemical and electrothermal coupling. Building on the advanced computational technology of the Imperial College Ocean Model, this new development leads the way towards a complex multiphase code using arbitrary unstructured and adaptive meshes, and domains decomposed to run in parallel over a cluster of workstations or a dedicated parallel computer. These facilities will allow efficient and accurate modelling of multiphase flows which capture large- and small-scale transport phenomena, while preserving the important geology and/or surface topology to make the results physically meaningful and realistic. Applications include modelling of contaminant transport in aquifers, multiphase flow during hydrocarbon production, migration of carbon dioxide during sequestration, and evaluation of the design and safety of nuclear reactors. Simulations of the streaming potential resulting from multiphase flow in laboratory- and field-scale models demonstrate that streaming potential signals originate at fluid fronts, and at geologic boundaries where fluid saturation changes. This suggests that downhole measurements of streaming potential may be used to inform production strategies in oil and gas reservoirs. As water encroaches on an oil production well, the streaming-potential signal associated with the water front encompasses the well even when the front is up to 100 m away, so the potential measured at the well starts to change significantly relative to a distant reference electrode. Variations in the geometry of the encroaching water front could be characterized using an array of electrodes positioned along the well

  17. Advances in Telescope and Detector Technologies - Impacts on the Study and Understanding of Binary Star and Exoplanet Systems

    NASA Astrophysics Data System (ADS)

    Guinan, Edward F.; Engle, Scott; Devinney, Edward J.

    2012-04-01

    Current and planned telescope systems (both on the ground and in space) as well as new technologies will be discussed with emphasis on their impact on the studies of binary star and exoplanet systems. Although no telescopes or space missions are primarily designed to study binary stars (what a pity!), several are available (or will be shortly) to study exoplanet systems. Nonetheless those telescopes and instruments can also be powerful tools for studying binary and variable stars. For example, early microlensing missions (mid-1990s) such as EROS, MACHO and OGLE were initially designed for probing dark matter in the halos of galaxies but, serendipitously, these programs turned out to be a bonanza for the studies of eclipsing binaries and variable stars in the Magellanic Clouds and in the Galactic Bulge. A more recent example of this kind of serendipity is the Kepler Mission. Although Kepler was designed to discover exoplanet transits (and so far has been very successful, returning many planetary candidates), Kepler is turning out to be a ``stealth'' stellar astrophysics mission returning fundamentally important and new information on eclipsing binaries, variable stars and, in particular, providing a treasure trove of data of all types of pulsating stars suitable for detailed Asteroseismology studies. With this in mind, current and planned telescopes and networks, new instruments and techniques (including interferometers) are discussed that can play important roles in our understanding of both binary star and exoplanet systems. Recent advances in detectors (e.g. laser frequency comb spectrographs), telescope networks (both small and large - e.g. Super-WASP, HAT-net, RoboNet, Las Combres Observatory Global Telescope (LCOGT) Network), wide field (panoramic) telescope systems (e.g. Large Synoptic Survey Telescope (LSST) and Pan-Starrs), huge telescopes (e.g. the Thirty Meter Telescope (TMT), the Overwhelming Large Telescope (OWL) and the Extremely Large Telescope (ELT

  18. Recent advances in understanding the biomolecular basis of chronic beryllium disease: a review.

    PubMed

    McCleskey, T Mark; Buchner, Virginia; Field, R William; Scott, Brian L

    2009-01-01

    In this review we summarize the work conducted over the past decade that has advanced our knowledge of pulmonary diseases associated with exposure to beryllium that has provided a molecular-based understanding of the chemistry, immunopathology, and immunogenetics of beryllium toxicity. Beryllium is a strong and lightweight metal that generates and reflects neutrons, resists corrosion, is transparent to X-rays, and conducts electricity. Beryllium is one of the most toxic elements on the periodic table, eliciting in susceptible humans (a) an allergic immune response known as beryllium sensitization (BeS); (b) acute beryllium disease, an acutely toxic, pneumonitis-like lung condition resulting from exposure to high beryllium concentrations that are rarely seen in modern industry; and (c) chronic beryllium disease (CBD) following either high or very low levels of exposure. Because of its exceptional strength, stability, and heat-absorbing capability, beryllium is used in many important technologies in the modern world. In the early 1940s, beryllium was recognized as posing an occupational hazard in manufacturing and production settings. Although acute beryllium disease is now rare, beryllium is an insidious poison with a latent toxicity and the risk of developing CBD persists. Chronic beryllium disease-a systemic granulomatous lung disorder caused by a specific delayed immune response to beryllium within a few months to several decades after exposure-has been called the "unrecognized epidemic". Although not a disease in itself, BeS, the innate immune response to beryllium identified by an abnormal beryllium lymphocyte proliferation test result, is a population-based predictor of CBD. Genetic susceptibility to CBD is associated with alleles of the major histocompatibility gene, human leukocyte antigen DP (HLA-DP) containing glutamic acid at the 69th position of the beta chain (HLA-DPbeta-E69). Other genes are likely to be involved in the disease process, and research on

  19. Recent advances in understanding/management of non-alcoholic steatohepatitis.

    PubMed

    Pacana, Tommy; Sanyal, Arun J

    2015-01-01

    Non-alcoholic steatohepatitis (NASH) can lead to advanced fibrosis, hepatocellular carcinoma, and end-stage liver disease requiring liver transplantation. A myriad of pathways and genetic influence contribute to NASH pathogenesis and liver disease progression. Diagnosing patients with NASH and advanced fibrosis is critical prior to treatment and prognostication. There has been ongoing interest in developing non-invasive biomarkers and tools for identifying NASH and advanced fibrosis. To date, there has been no approved therapy for NASH. Recently, the FLINT (Farnesoid X Receptor [FXR] Ligand Obeticholic Acid in NASH Treatment) trial provided promising results of the efficacy of obeticholic acid, a farnesoid X receptor agonist, in improving histological features of NASH and fibrosis. Long-term studies are needed to assess the safety of obeticholic acid and its effects on liver- and cardiovascular-related outcomes. PMID:25926979

  20. 48 CFR 1552.215-74 - Advanced understanding-uncompensated time.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-uncompensated time. 1552.215-74 Section 1552.215-74 Federal Acquisition Regulations System ENVIRONMENTAL... Clauses 1552.215-74 Advanced understanding—uncompensated time. As prescribed in 1515.408(b), insert the...—Uncompensated Time (AUG 1999) (a) The estimated cost of this contract is based upon the Contractor's...

  1. Understanding Fluorescence Measurements through a Guided-Inquiry and Discovery Experiment in Advanced Analytical Laboratory

    ERIC Educational Resources Information Center

    Wilczek-Vera, Grazyna; Salin, Eric Dunbar

    2011-01-01

    An experiment on fluorescence spectroscopy suitable for an advanced analytical laboratory is presented. Its conceptual development used a combination of the expository and discovery styles. The "learn-as-you-go" and direct "hands-on" methodology applied ensures an active role for a student in the process of visualization and discovery of concepts.…

  2. How Syntactic Reasoners Can Develop Understanding, Evaluate Conjectures, and Generate Counterexamples in Advanced Mathematics

    ERIC Educational Resources Information Center

    Weber, Keith

    2009-01-01

    This paper presents a case study of a highly successful student whose exploration of an advanced mathematical concept relies predominantly on syntactic reasoning, such as developing formal representations of mathematical ideas and making logical deductions. This student is observed as he learns a new mathematical concept and then completes…

  3. Advances in Modern Botnet Understanding and the Accurate Enumeration of Infected Hosts

    ERIC Educational Resources Information Center

    Nunnery, Christopher Edward

    2011-01-01

    Botnets remain a potent threat due to evolving modern architectures, inadequate remediation methods, and inaccurate measurement techniques. In response, this research exposes the architectures and operations of two advanced botnets, techniques to enumerate infected hosts, and pursues the scientific refinement of infected-host enumeration data by…

  4. Annual Research Review: Impact of Advances in Genetics in Understanding Developmental Psychopathology

    ERIC Educational Resources Information Center

    Addington, Anjene M.; Rapoport, Judith L.

    2012-01-01

    It was hoped that diagnostic guidelines for, and treatment of, child psychiatric disorders in DSM-5 would be informed by the wealth of clinical genetic research related to neurodevelopmental disorders. In spite of remarkable advances in genetic technology, this has not been the case. Candidate gene, genome-wide association, and rare copy number…

  5. A Study of Three Impoverished Preschoolers with Advanced Understanding of Literacy.

    ERIC Educational Resources Information Center

    Smith, Susan Robinson; Rotman, Molly

    A study examined factors that may foster advanced knowledge of literacy among impoverished preschoolers who are generally found to be academically at-risk in learning to read. Six preschoolers enrolled in a Head Start program were identified by teacher recommendation as showing profound interest in written language (looking at books, writing…

  6. Satellite soil moisture for advancing our understanding of earth system processes and climate change

    NASA Astrophysics Data System (ADS)

    Dorigo, Wouter; de Jeu, Richard

    2016-06-01

    Soil moisture products obtained from active and passive microwave satellites have reached maturity during the last decade (De Jeu and Dorigo, 2016): On the one hand, research algorithms that were initially applied to sensors designed for other purposes, e.g., for measuring wind speed (e.g. the Advanced Scatterometer (ASCAT)), sea ice, or atmospheric parameters (e.g. the TRMM Microwave Imager (TMI) and the Advanced Microwave Scanning Radiometer - Earth Observing System AMSR-E), have developed into fully operational products. On the other hand, dedicated soil moisture satellite missions were designed and launched by ESA (the Soil Moisture Ocean Salinity (SMOS) mission) and NASA (the Soil Moisture Active Passive (SMAP) mission).

  7. Commentary: Advancing Our Understanding of Asian American Child Development: History, Context, and Culture as Essential Considerations.

    PubMed

    McLoyd, Vonnie C

    2016-07-01

    The Special Section will help scholars make informed choices about how to conceptualize developmental processes and assess contextually and culturally relevant variables in future research with Asian American children and youth. It undertakes tasks and addresses challenges that have broad relevance to the study of developmental processes and stands as a reminder of the vital role of interdisciplinary perspectives in the advancement of developmental science. PMID:27392798

  8. Beyond Homophily: A Decade of Advances in Understanding Peer Influence Processes

    ERIC Educational Resources Information Center

    Brechwald, Whitney A.; Prinstein, Mitchell J.

    2011-01-01

    This article reviews empirical and theoretical contributions to a multidisciplinary understanding of peer influence processes in adolescence over the past decade. Five themes of peer influence research from this decade were identified, including a broadening of the range of behaviors for which peer influence occurs, distinguishing the sources of…

  9. Issues In-Depth: Advancing Understanding of Drug Addiction and Treatment

    ERIC Educational Resources Information Center

    Miller, Roxanne Greitz

    2009-01-01

    While most school districts utilize a drug abuse resistance curriculum, as science teachers, it is our responsibility to understand the science behind drug addiction in order to most effectively educate our students against drug abuse. In the last two decades, increases in scientific technology have permitted significant discoveries surrounding…

  10. Recent advances in the understanding of male lower urinary tract symptoms (LUTS)

    PubMed Central

    Kahokehr, Arman A.; Gilling, Peter J.

    2016-01-01

    In this review, we have looked at three important areas in understanding male lower urinary tract symptoms. These are improvement in terminology, detrusor underactivity, and nocturia. Benign prostatic hyperplasia leading to bladder outlet obstruction has been covered in a previous review. PMID:27134738

  11. Recent advances in the understanding of male lower urinary tract symptoms (LUTS).

    PubMed

    Kahokehr, Arman A; Gilling, Peter J

    2016-01-01

    In this review, we have looked at three important areas in understanding male lower urinary tract symptoms. These are improvement in terminology, detrusor underactivity, and nocturia. Benign prostatic hyperplasia leading to bladder outlet obstruction has been covered in a previous review. PMID:27134738

  12. New test techniques and analytical procedures for understanding the behavior of advanced propellers

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Bober, L. J.; Neumann, H. E.

    1983-01-01

    Analytical procedures and experimental techniques were developed to improve the capability to design advanced high speed propellers. Some results from the propeller lifting line and lifting surface aerodynamic analysis codes are compared with propeller force data, probe data and laser velocimeter data. In general, the code comparisons with data indicate good qualitative agreement. A rotating propeller force balance demonstrated good accuracy and reduced test time by 50 percent. Results from three propeller flow visualization techniques are shown which illustrate some of the physical phenomena occurring on these propellers.

  13. Toward system-level understanding of baculovirus–host cell interactions: from molecular fundamental studies to large-scale proteomics approaches

    PubMed Central

    Monteiro, Francisca; Carinhas, Nuno; Carrondo, Manuel J. T.; Bernal, Vicente; Alves, Paula M.

    2012-01-01

    Baculoviruses are insect viruses extensively exploited as eukaryotic protein expression vectors. Molecular biology studies have provided exciting discoveries on virus–host interactions, but the application of omic high-throughput techniques on the baculovirus–insect cell system has been hampered by the lack of host genome sequencing. While a broader, systems-level analysis of biological responses to infection is urgently needed, recent advances on proteomic studies have yielded new insights on the impact of infection on the host cell. These works are reviewed and critically assessed in the light of current biological knowledge of the molecular biology of baculoviruses and insect cells. PMID:23162544

  14. Recent advances in understanding the reinforcing ability and mechanism of carbon nanotubes in ceramic matrix composites

    NASA Astrophysics Data System (ADS)

    Estili, Mehdi; Sakka, Yoshio

    2014-12-01

    Since the discovery of carbon nanotubes (CNTs), commonly referred to as ultimate reinforcement, the main purpose for fabricating CNT-ceramic matrix composites has been mainly to improve the fracture toughness and strength of the ceramic matrix materials. However, there have been many studies reporting marginal improvements or even the degradation of mechanical properties. On the other hand, those studies claiming noticeable toughening measured using indentation, which is an indirect/unreliable characterization method, have not demonstrated the responsible mechanisms applicable to the nanoscale, flexible CNTs; instead, those studies proposed those classical methods applicable to microscale fiber/whisker reinforced ceramics without showing any convincing evidence of load transfer to the CNTs. Therefore, the ability of CNTs to directly improve the macroscopic mechanical properties of structural ceramics has been strongly questioned and debated in the last ten years. In order to properly discuss the reinforcing ability (and possible mechanisms) of CNTs in a ceramic host material, there are three fundamental questions to our knowledge at both the nanoscale and macroscale levels that need to be addressed: (1) does the intrinsic load-bearing ability of CNTs change when embedded in a ceramic host matrix?; (2) when there is an intimate atomic-level interface without any chemical reaction with the matrix, could one expect any load transfer to the CNTs along with effective load bearing by them during crack propagation?; and (3) considering their nanometer-scale dimensions, flexibility and radial softness, are the CNTs able to improve the mechanical properties of the host ceramic matrix at the macroscale when individually, intimately and uniformly dispersed? If so, how? Also, what is the effect of CNT concentration in such a defect-free composite system? Here, we briefly review the recent studies addressing the above fundamental questions. In particular, we discuss the new

  15. Marketing fundamentals.

    PubMed

    Redmond, W H

    2001-01-01

    This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined. PMID:11401791

  16. Recent advances in understanding and managing cystic fibrosis transmembrane conductance regulator dysfunction

    PubMed Central

    Alton, Eric W.F.W.

    2015-01-01

    Cystic fibrosis is the most common autosomal recessive genetic disease in Caucasians and has been extensively studied for many decades. The cystic fibrosis transmembrane conductance regulator gene was identified in 1989. It encodes a complex protein which has numerous cellular functions. Our understanding of cystic fibrosis pathophysiology and genetics is constantly expanding and being refined, leading to improved management of the disease and increased life expectancy in affected individuals. PMID:26097737

  17. The Understanding by Design Guide to Advanced Concepts in Creating and Reviewing Units

    ERIC Educational Resources Information Center

    McTighe, Jay; Wiggins, Grant

    2012-01-01

    Regardless of your stage at implementing the design tools and using the improved template for Understanding by Design[R] (UbD), this companion to "The UbD Guide to Creating High-Quality Units" is essential for taking your work to a higher plane. This volume features a set of hands-on modules containing worksheets, models, and self-assessments that…

  18. Recent advances in understanding and managing cystic fibrosis transmembrane conductance regulator dysfunction.

    PubMed

    Griesenbach, Uta; Alton, Eric W F W

    2015-01-01

    Cystic fibrosis is the most common autosomal recessive genetic disease in Caucasians and has been extensively studied for many decades. The cystic fibrosis transmembrane conductance regulator gene was identified in 1989. It encodes a complex protein which has numerous cellular functions. Our understanding of cystic fibrosis pathophysiology and genetics is constantly expanding and being refined, leading to improved management of the disease and increased life expectancy in affected individuals. PMID:26097737

  19. Imaging mass spectrometry of the visual system: Advancing the molecular understanding of retina degenerations.

    PubMed

    Bowrey, Hannah E; Anderson, David M; Pallitto, Patrick; Gutierrez, Danielle B; Fan, Jie; Crouch, Rosalie K; Schey, Kevin L; Ablonczy, Zsolt

    2016-04-01

    Visual sensation is fundamental for quality of life, and loss of vision to retinal degeneration is a debilitating condition. The eye is the only part of the central nervous system that can be noninvasively observed with optical imaging. In the clinics, various spectroscopic methods provide high spatial resolution images of the fundus and the developing degenerative lesions. However, the currently utilized tools are not specific enough to establish the molecular underpinnings of retinal diseases. In contrast, mass spectrometric imaging (MSI) is a powerful tool to identify molecularly specific disease indicators and classification markers. This technique is particularly well suited to the eye, where molecular information can be correlated with clinical data collected via noninvasive diagnostic imaging modalities. Recent studies during the last few recent years have uncovered a plethora of new spatially defined molecular information on several vision-threatening diseases, including age-related macular degeneration, Stargardt disease, glaucoma, cataract, as well as lipid disorders. Even though MS inside the eye cannot be performed noninvasively, by linking diagnostic and molecular information, these studies are the first step toward the development of smart ophthalmic diagnostic and surgical tools. Here, we provide an overview of current approaches applying MSI technology to ocular pathology. PMID:26586164

  20. A 'bottom up', ab initio computational approach to understanding fundamental photophysical processes in nitrogen containing heterocycles, DNA bases and base pairs.

    PubMed

    Marchetti, Barbara; Karsili, Tolga N V; Ashfold, Michael N R; Domcke, Wolfgang

    2016-07-27

    The availability of non-radiative decay mechanisms by which photoexcited molecules can revert to their ground electronic state, without experiencing potentially deleterious chemical transformation, is fundamental to molecular photostability. This Perspective Article combines results of new ab initio electronic structure calculations and prior experimental data in an effort to systematise trends in the non-radiative decay following UV excitation of selected families of heterocyclic molecules. We start with the prototypical uni- and bicyclic molecules phenol and indole, and explore the structural and photophysical consequences of incorporating progressively more nitrogen atoms within the respective ring structures en route to the DNA bases thymine, cytosine, adenine and guanine. For each of the latter, we identify low energy non-radiative decay pathways via conical intersections with the ground state potential energy surface accessed by out-of-plane ring deformations. This is followed by summary descriptions and illustrations of selected rival (electron driven H atom transfer) non-radiative excited state decay processes that demand consideration once the nucleobases are merely components in larger biomolecular systems like nucleosides, and both individual and stacked base-pairs. PMID:26980149

  1. Sarcasm and advanced theory of mind understanding in children and adults with prelingual deafness.

    PubMed

    O'Reilly, Karin; Peterson, Candida C; Wellman, Henry M

    2014-07-01

    Two studies addressed key theoretical debates in theory of mind (ToM) development by comparing (a) deaf native signers (n = 18), (b) deaf late signers (n = 59), and (c) age-matched hearing persons (n = 74) in childhood (Study 1: n = 81) and adulthood (Study 2: n = 70) on tests of first- and second-order false belief and conversational sarcasm. Results showed ToM development to be a life span phenomenon for deaf and hearing people alike. Native and late signers were outperformed by hearing peers on advanced ToM in childhood (M = 9 years), but in adulthood (M = 40 years), native signers had caught up, whereas late signers had not. Findings highlight the extended importance of conversational interaction for ToM growth. PMID:24798505

  2. Understanding the impact of deep brain stimulation on ambulatory activity in advanced Parkinson's disease.

    PubMed

    Rochester, Lynn; Chastin, Sebastien Francois Martin; Lord, Sue; Baker, Katherine; Burn, David John

    2012-06-01

    Whilst deep brain stimulation of the subthalamic nucleus (DBS-STN) improves the motor symptoms of Parkinson's disease (PD), its effect on daily activity is unknown. We aimed to quantify changes in ambulatory activity following DBS-STN in advanced PD using novel accelerometry based measures that describe changes to the volume and pattern of walking. Seventeen participants with advanced PD were measured over a 7-day period using an activPAL (™) activity monitor. Data were collected 6 weeks before and 6 months after surgery and included measures that describe the volume and pattern of ambulatory activity (number of steps per day, accumulation, diversity and variability of walking time), alongside standard measures for disease severity, freezing of gait, gait speed, and extended activities of daily living. Activity outcomes were compared pre- and 6 months post-surgery using linear mixed models and correlated with standard outcomes. The results of this study are despite significant improvements in motor symptoms after surgery, the volume of ambulatory activity (total number of steps per day) did not change (P = 0.468). However, significant increases in length and variability of walking bouts emerged, suggesting improvements in diversity and flexibility of walking patterns. Motor severity and extended activities of daily living scores were significantly correlated with walking bout variability but not with volume of walking. Thus, the conclusions are reduction in motor symptom severity after DBS-STN translated into selective improvements in daily activity. Novel measures derived from accelerometry provide a discrete measure of performance and allow closer interpretation of the impact of DBS-STN on real-world activity. PMID:22086738

  3. Advances in Understanding Global Water Cycle with Advent of Global Precipitation Measurement (GPM) Mission

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Starr, David (Technical Monitor)

    2002-01-01

    Within this decade the internationally organized Global Precipitation Measurement (GPM) Mission will take an important step in creating a global precipitation observing system from space. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams beginning with very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and then on to blends of the former datastreams with additional lower-caliber PMW-based and IR-based rain retrievals. Within the context of the now emerging global water & energy cycle (GWEC) programs of a number of research agencies throughout the world, GPM serves as a centerpiece space mission for improving our understanding of the global water cycle from a global measurement perspective. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in climate, e.g., climate warming. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination. This paper presents an overview of the GPM Mission and how its observations can be used within the framework of the oceanic and continental water budget equations to determine whether a given perturbation in precipitation is indicative of an actual rate change in the global water cycle, consistent with required responses in water storage and/or water flux transport processes, or whether it is the natural variability of a fixed rate cycle.

  4. Advances In Understanding Global Water Cycle With Advent of GPM Mission

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.

    2002-01-01

    During the coming decade, the internationally organized Global Precipitation Measurement (GPM) Mission will take an important step in creating a global precipitation observing system from space based on an international fleet of satellites operated as a constellation. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams beginning with very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and then on to blends of the former datastreams with additional lower-caliber PMW-based and IR-based rain retrievals. Within the context of the now emerging global water & energy cycle (GWEC) programs of a number of research agencies throughout the world, GPM serves as a centerpiece space mission for improving our understanding of the Earth's water cycle from a global measurement perspective and on down to regional scales and below. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in climate, e.g., climate warming. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination. This paper first presents an overview of the GPM Mission and how its overriding scientific objectives for climate, weather, and hydrology flow from the anticipated improvements that are being planned for the constellation-based measuring system. Next, the paper shows how the GPM observations can be used within the framework of the oceanic and continental water budget equations to determine whether a given perturbation in precipitation is indicative of an actual rate change in the water cycle, consistent with required responses in water storage and/or water flux transport processes, or whether it is simply part of the natural

  5. Recent advances in the understanding and management of IgA nephropathy

    PubMed Central

    Lai, Kar Neng; Leung, Joseph C.K.; Tang, Sydney C.W.

    2016-01-01

    Since its first description in 1968, IgA nephropathy has remained the most common form of primary glomerulonephritis leading to chronic kidney disease in developed countries. The clinical progression varies, and consequent end-stage renal disease occurs in 30% to 40% of patients 20 to 30 years after the first clinical presentation. Current data implicate overproduction of aberrantly glycosylated IgA1 as being pivotal in the induction of renal injury. Effective and specific treatment is still lacking, and new therapeutic approaches will be developed after better understanding the disease pathogenesis.

  6. Pediatric Cerebellar Tumors: Emerging Imaging Techniques and Advances in Understanding of Genetic Features.

    PubMed

    Choudhri, Asim F; Siddiqui, Adeel; Klimo, Paul

    2016-08-01

    Cerebellar tumors are the most common group of solid tumors in children. MR imaging provides an important role in characterization of these lesions, surgical planning, and postsurgical surveillance. Preoperative imaging can help predict the histologic subtype of tumors, which can provide guidance for surgical planning. Beyond histology, pediatric brain tumors are undergoing new classification schemes based on genetic features. Intraoperative MR imaging has emerged as an important tool in the surgical management of pediatric brain tumors. Effective understanding of the imaging features of pediatric cerebellar tumors can benefit communication with neurosurgeons and neuro-oncologists and can improve patient management. PMID:27423803

  7. Recent advances in understanding stratospheric dynamics and transport processes - Application of satellite data to their interpretation

    NASA Technical Reports Server (NTRS)

    Grose, W. L.

    1984-01-01

    The present paper discusses the use of the transformed Eulerian (or 'residual') mean-flow formulation, the Eliassen-Palm flux, and Ertel's potential vorticity to provide an increased understanding of wave, mean-flow interactions, and constituent transport processes in the stratosphere. Temperature and ozone data retrieved from radiance profiles obtained by the LIMS instrument on the Nimbus 7 satellite are utilized in conjunction with these theoretical concepts for the interpretation of phenomena that occurred during the major and minor warmings of January-February 1979. The results illustrate the insight provided by these concepts and demonstrate that useful diagnostic quantities can be derived from global satellite temperature fields.

  8. The impact of recent advances in genetics in understanding disease mechanisms underlying the long QT syndromes.

    PubMed

    Harmer, Stephen C; Tinker, Andrew

    2016-07-01

    Long QT syndrome refers to a characteristic abnormality of the electrocardiogram and it is associated with a form of ventricular tachycardia known as torsade-de-pointes and sudden arrhythmic death. It can occur as part of a hereditary syndrome or can be acquired usually because of drug administration. Here we review recent genetic, molecular and cellular discoveries and outline how they have furthered our understanding of this disease. Specifically we focus on compound mutations, genome wide association studies of QT interval, modifier genes and the therapeutic implications of this recent work. PMID:26910742

  9. Progress toward advanced understanding of metabotropic glutamate receptors: structure, signaling and therapeutic indications

    PubMed Central

    Yin, Shen; Niswender, Colleen M.

    2014-01-01

    The metabotropic glutamate (mGlu) receptors are a group of Class C Seven Transmembrane Spanning/G Protein Coupled Receptors (7TMRs/GPCRs). These receptors are activated by glutamate, one of the standard amino acids and the major excitatory neurotransmitter. By activating G protein-dependent and non G protein-dependent signaling pathways, mGlus modulate glutamatergic transmission in both the periphery and throughout the central nervous system. Since the discovery of the first mGlu receptor, especially the last decade, a great deal of progress has been made in understanding the signaling, structure, pharmacological manipulation and therapeutic indications of the 8 mGlu members. PMID:24793301

  10. Advances in the understanding of delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage

    PubMed Central

    Flynn, Liam; Andrews, Peter

    2015-01-01

    Delayed cerebral ischaemia has been described as the single most important cause of morbidity and mortality in patients who survive the initial aneurysmal subarachnoid haemorrhage. Our understanding of the pathophysiology of delayed cerebral ischaemia is meagre at best and the calcium channel blocker nimodipine remains the only intervention to consistently improve functional outcome after aneurysmal subarachnoid haemorrhage. There is substantial evidence to support cerebral vessel narrowing as a causative factor in delayed cerebral ischaemia, but contemporary research demonstrating improvements in vessel narrowing has failed to show improved functional outcomes. This has encouraged researchers to investigate other potential causes of delayed cerebral ischaemia, such as early brain injury, microthrombosis, and cortical spreading depolarisation. Adherence to a common definition of delayed cerebral ischaemia is needed in order to allow easier assessment of studies using multiple different terms. Furthermore, improved recognition of delayed cerebral ischaemia would not only allow for faster treatment but also better assessment of interventions. Finally, understanding nimodipine’s mechanism of action may allow us to develop similar agents with improved efficacy. PMID:26937276

  11. Recent advances in understanding of meiosis initiation and the apomictic pathway in plants.

    PubMed

    Wang, Chung-Ju R; Tseng, Ching-Chih

    2014-01-01

    Meiosis, a specialized cell division to produce haploid cells, marks the transition from a sporophytic to a gametophytic generation in the life cycle of plants. In angiosperms, meiosis takes place in sporogenous cells that develop de novo from somatic cells in anthers or ovules. A successful transition from the mitotic cycle to the meiotic program in sporogenous cells is crucial for sexual reproduction. By contrast, when meiosis is bypassed or a mitosis-like division occurs to produce unreduced cells, followed by the development of an embryo sac, clonal seeds can be produced by apomixis, an asexual reproduction pathway found in 400 species of flowering plants. An understanding of the regulation of entry into meiosis and molecular mechanisms of apomictic pathway will provide vital insight into reproduction for plant breeding. Recent findings suggest that AM1/SWI1 may be the key gene for entry into meiosis, and increasing evidence has shown that the apomictic pathway is epigenetically controlled. However, the mechanism for the initiation of meiosis during sexual reproduction or for its omission in the apomictic pathway still remains largely unknown. Here we review the current understanding of meiosis initiation and the apomictic pathway and raised several questions that are awaiting further investigation. PMID:25295051

  12. Recent advances in understanding of meiosis initiation and the apomictic pathway in plants

    PubMed Central

    Wang, Chung-Ju R.; Tseng, Ching-Chih

    2014-01-01

    Meiosis, a specialized cell division to produce haploid cells, marks the transition from a sporophytic to a gametophytic generation in the life cycle of plants. In angiosperms, meiosis takes place in sporogenous cells that develop de novo from somatic cells in anthers or ovules. A successful transition from the mitotic cycle to the meiotic program in sporogenous cells is crucial for sexual reproduction. By contrast, when meiosis is bypassed or a mitosis-like division occurs to produce unreduced cells, followed by the development of an embryo sac, clonal seeds can be produced by apomixis, an asexual reproduction pathway found in 400 species of flowering plants. An understanding of the regulation of entry into meiosis and molecular mechanisms of apomictic pathway will provide vital insight into reproduction for plant breeding. Recent findings suggest that AM1/SWI1 may be the key gene for entry into meiosis, and increasing evidence has shown that the apomictic pathway is epigenetically controlled. However, the mechanism for the initiation of meiosis during sexual reproduction or for its omission in the apomictic pathway still remains largely unknown. Here we review the current understanding of meiosis initiation and the apomictic pathway and raised several questions that are awaiting further investigation. PMID:25295051

  13. An advanced understanding of the specific effects of xylan and surface lignin contents on enzymatic hydrolysis of lignocellulosic biomass

    SciTech Connect

    Ju, Xiaohui; Engelhard, Mark H.; Zhang, Xiao

    2013-01-17

    A deep understanding of biomass recalcitrance has been hampered by the intricate and heterogeneous nature of pretreated biomass substrates obtained from random deconstruction methods. In this study, we established a unique methodology based on chemical pulping principles to create "reference substrates" with intact cellulose fibers and controlled morphological and chemical properties that enable us to investigate the individual effect of xylan, bulk, and surface lignin content on enzymatic hydrolysis. We also developed and demonstrated an X-ray photoelectron spectroscopy (XPS) technique for quantifying surface lignin content on biomass substrates. The results from this study show that, apart from its hindrance effect, xylan can facilitate cellulose fibril swelling and thus create more accessible surface area, which improves enzyme and substrate interactions. Surface lignin has a significant impact on enzyme adsorption kinetics and hydrolysis rate. Advanced understanding of xylan, bulk, and surface lignin effects provides critical information for an effective biomass conversion process.

  14. Recent Advances in Improvement of Forecast Skill and Understanding Climate Processes Using AIRS Version-5 Products

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena; Rosenberg, Robert

    2012-01-01

    AIRS/AMSU is the state of the art infrared and microwave atmospheric sounding system flying aboard EOS Aqua. These observations, covering the period September 2002 until the present, have been analyzed using the AIRS Science Team Version-5 retrieval algorithm. AIRS is a high spectral resolution infrared grating spectrometer with spect,ral coverage from 650 per centimeter extending to 2660 per centimeter, with low noise and a spectral resolving power of 2400. A brief overview of the AIRS Version-5 retrieval procedure will be presented, including the AIRS channels used in different steps in the retrieval process. Many researchers have used these products to make significant advances in both climate and weather applications. Recent significant results of these experiments will be presented, including results showing that 1) assimilation of AIRS Quality Controlled temperature profiles into a General Circulation Model (GCM) significantly improves the ability to predict storm tracks of intense precipitation events; and 2) anomaly time-series of Outgoing Longwave Radiation (OLR) computed using AIRS sounding products closely match those determined from the CERES instrument, and furthermore explain that the phenomenon that global and especially tropical mean OLR have been decreasing since September 2002 is a result of El Nino/La Nina oscillations during this period.

  15. Recent Advances in Understanding and Mitigating Adipogenic and Metabolic Effects of Antipsychotic Drugs

    PubMed Central

    Gohlke, Julia M.; Dhurandhar, Emily J.; Correll, Christoph U.; Morrato, Elaine H.; Newcomer, John W.; Remington, Gary; Nasrallah, Henry A.; Crystal, Stephen; Nicol, Ginger; Allison, David B.

    2012-01-01

    Although offering many benefits for several psychiatric disorders, antipsychotic drugs (APDs) as a class have a major liability in their tendency to promote adiposity, obesity, and metabolic dysregulation in an already metabolically vulnerable population. The past decade has witnessed substantial research aimed at investigating the mechanisms of these adverse effects and mitigating them. On July 11 and 12, 2011, with support from 2 NIH institutes, leading experts convened to discuss current research findings and to consider future research strategies. Five areas where significant advances are being made emerged from the conference: (1) methodological issues in the study of APD effects; (2) unique characteristics and needs of pediatric patients; (3) genetic components underlying susceptibility to APD-induced metabolic effects; (4) APD effects on weight gain and adiposity in relation to their acute effects on glucose regulation and diabetes risk; and (5) the utility of behavioral, dietary, and pharmacological interventions in mitigating APD-induced metabolic side effects. This paper summarizes the major conclusions and important supporting data from the meeting. PMID:22754543

  16. Recent Advances in Understanding of NASH: MicroRNAs as Both Biochemical Markers and Players

    PubMed Central

    Vincent, Robert; Sanyal, Arun

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatis (NASH) are becoming the dominant liver diseases in the US and Western World. Extensive work is being done to diagnose, understand, and explore the pathogenesis of these multivariable complex diseases. Recently a new avenue of biologic regulation is being explored. MicroRNAs are non-coding RNAs that modulate the expression of multiple genes and have been implicated in multiple diseases. Recently there is a growing body of evidence supporting a significant role of microRNAs in NAFLD pathogenesis and progression to NASH, and hinting at their use as targets, biomarkers and potential therapeutic tools. This review is designed to highlight some of the recent work on a few of the key microRNAs involved in the pathogenesis of NAFLD and NASH. PMID:25574453

  17. How fundamental are fundamental constants?

    NASA Astrophysics Data System (ADS)

    Duff, M. J.

    2015-01-01

    I argue that the laws of physics should be independent of one's choice of units or measuring apparatus. This is the case if they are framed in terms of dimensionless numbers such as the fine structure constant, ?. For example, the standard model of particle physics has 19 such dimensionless parameters whose values all observers can agree on, irrespective of what clock, rulers or scales? they use to measure them. Dimensional constants, on the other hand, such as ?, c, G, e and k ?, are merely human constructs whose number and values differ from one choice of units to the next. In this sense, only dimensionless constants are 'fundamental'. Similarly, the possible time variation of dimensionless fundamental 'constants' of nature is operationally well defined and a legitimate subject of physical enquiry. By contrast, the time variation of dimensional constants such as ? or ? on which a good many (in my opinion, confusing) papers have been written, is a unit-dependent phenomenon on which different observers might disagree depending on their apparatus. All these confusions disappear if one asks only unit-independent questions. We provide a selection of opposing opinions in the literature and respond accordingly.

  18. Advances in Our Understanding of Oxylipins Derived from Dietary PUFAs12

    PubMed Central

    Gabbs, Melissa; Leng, Shan; Devassy, Jessay G; Monirujjaman, Md; Aukema, Harold M

    2015-01-01

    Oxylipins formed from polyunsaturated fatty acids (PUFAs) are the main mediators of PUFA effects in the body. They are formed via cyclooxygenase, lipoxygenase, and cytochrome P450 pathways, resulting in the formation of prostaglandins, thromboxanes, mono-, di-, and tri-hydroxy fatty acids (FAs), epoxy FAs, lipoxins, eoxins, hepoxilins, resolvins, protectins (also called neuroprotectins in the brain), and maresins. In addition to the well-known eicosanoids derived from arachidonic acid, recent developments in lipidomic methodologies have raised awareness of and interest in the large number of oxylipins formed from other PUFAs, including those from the essential FAs and the longer-chain n–3 (ω-3) PUFAs. Oxylipins have essential roles in normal physiology and function, but can also have detrimental effects. Compared with the oxylipins derived from n–3 PUFAs, oxylipins from n–6 PUFAs generally have greater activity and more inflammatory, vasoconstrictory, and proliferative effects, although there are notable exceptions. Because PUFA composition does not necessarily reflect oxylipin composition, comprehensive analysis of the oxylipin profile is necessary to understand the overall physiologic effects of PUFAs mediated through their oxylipins. These analyses should include oxylipins derived from linoleic and α-linolenic acids, because these largely unexplored bioactive oxylipins constitute more than one-half of oxylipins present in tissues. Because collated information on oxylipins formed from different PUFAs is currently unavailable, this review provides a detailed compilation of the main oxylipins formed from PUFAs and describes their functions. Much remains to be elucidated in this emerging field, including the discovery of more oxylipins, and the understanding of the differing biological potencies, kinetics, and isomer-specific activities of these novel PUFA metabolites. PMID:26374175

  19. Combining natural and man-made DNA tracers to advance understanding of hydrologic flow pathway evolution

    NASA Astrophysics Data System (ADS)

    Dahlke, H. E.; Walter, M. T.; Lyon, S. W.; Rosqvist, G. N.

    2014-12-01

    Identifying and characterizing the sources, pathways and residence times of water and associated constituents is critical to developing improved understanding of watershed-stream connections and hydrological/ecological/biogeochemical models. To date the most robust information is obtained from integrated studies that combine natural tracers (e.g. isotopes, geochemical tracers) with controlled chemical tracer (e.g., bromide, dyes) or colloidal tracer (e.g., carboxilated microspheres, tagged clay particles, microorganisms) applications. In the presented study we explore how understanding of sources and flow pathways of water derived from natural tracer studies can be improved and expanded in space and time by simultaneously introducing man-made, synthetic DNA-based microtracers. The microtracer used were composed of polylactic acid (PLA) microspheres into which short strands of synthetic DNA and paramagnetic iron oxide nanoparticles are incorporated. Tracer experiments using both natural tracers and the DNA-based microtracers were conducted in the sub-arctic, glacierized Tarfala (21.7 km2) catchment in northern Sweden. Isotopic hydrograph separations revealed that even though storm runoff was dominated by pre-event water the event water (i.e. rainfall) contributions to streamflow increased throughout the summer season as glacial snow cover decreased. This suggests that glaciers are a major source of the rainwater fraction in streamflow. Simultaneous injections of ten unique DNA-based microtracers confirmed this hypothesis and revealed that the transit time of water traveling from the glacier surface to the stream decreased fourfold over the summer season leading to instantaneous rainwater contributions during storm events. These results highlight that integrating simultaneous tracer injections (injecting tracers at multiple places at one time) with traditional tracer methods (sampling multiple times at one place) rather than using either approach in isolation can

  20. Advances in understanding the cell types and approaches used for generating induced pluripotent stem cells.

    PubMed

    Li, Jun; Song, Wei; Pan, Guangjin; Zhou, Jun

    2014-01-01

    Successfully reprogramming somatic cells to a pluripotent state generates induced pluripotent stem (iPS) cells (or iPSCs), which have extensive self-renewal capacity like embryonic stem cells (ESCs). iPSCs can also generate daughter cells that can further undergo differentiation into various lineages or terminally differentiate to reach their final functional state. The discovery of how to produce iPSCs opened a new field of stem cell research with both intellectual and therapeutic benefits. The huge potential implications of disease-specific or patient-specific iPSCs have impelled scientists to solve problems hindering their applications in clinical medicine, especially the issues of convenience and safety. To determine the range of tissue types amenable to reprogramming as well as their particular characteristics, cells from three embryonic germ layers have been assessed, and the advantages that some tissue origins have over fibroblast origins concerning efficiency and accessibility have been elucidated. To provide safe iPSCs in an efficient and convenient way, the delivery systems and combinations of inducing factors as well as the chemicals used to generate iPSCs have also been significantly improved in addition to the efforts on finding better donor cells. Currently, iPSCs can be generated without c-Myc and Klf4 oncogenes, and non-viral delivery integration-free chemically mediated reprogramming methods have been successfully employed with relatively satisfactory efficiency. This paper will review recent advances in iPS technology by highlighting tissue origin and generation of iPSCs. The obstacles that need to be overcome for clinical applications of iPSCs are also discussed. PMID:25037625

  1. Advances in understanding the cell types and approaches used for generating induced pluripotent stem cells

    PubMed Central

    2014-01-01

    Successfully reprogramming somatic cells to a pluripotent state generates induced pluripotent stem (iPS) cells (or iPSCs), which have extensive self-renewal capacity like embryonic stem cells (ESCs). iPSCs can also generate daughter cells that can further undergo differentiation into various lineages or terminally differentiate to reach their final functional state. The discovery of how to produce iPSCs opened a new field of stem cell research with both intellectual and therapeutic benefits. The huge potential implications of disease-specific or patient-specific iPSCs have impelled scientists to solve problems hindering their applications in clinical medicine, especially the issues of convenience and safety. To determine the range of tissue types amenable to reprogramming as well as their particular characteristics, cells from three embryonic germ layers have been assessed, and the advantages that some tissue origins have over fibroblast origins concerning efficiency and accessibility have been elucidated. To provide safe iPSCs in an efficient and convenient way, the delivery systems and combinations of inducing factors as well as the chemicals used to generate iPSCs have also been significantly improved in addition to the efforts on finding better donor cells. Currently, iPSCs can be generated without c-Myc and Klf4 oncogenes, and non-viral delivery integration-free chemically mediated reprogramming methods have been successfully employed with relatively satisfactory efficiency. This paper will review recent advances in iPS technology by highlighting tissue origin and generation of iPSCs. The obstacles that need to be overcome for clinical applications of iPSCs are also discussed. PMID:25037625

  2. Advancing the application of systems thinking in health: understanding the dynamics of neonatal mortality in Uganda

    PubMed Central

    2014-01-01

    Background Of the three million newborns that die each year, Uganda ranks fifth highest in neonatal mortality rates, with 43,000 neonatal deaths each year. Despite child survival and safe motherhood programmes towards reducing child mortality, insufficient attention has been given to this critical first month of life. There is urgent need to innovatively employ alternative solutions that take into account the intricate complexities of neonatal health and the health systems. In this paper, we set out to empirically contribute to understanding the causes of the stagnating neonatal mortality by applying a systems thinking approach to explore the dynamics arising from the neonatal health complexity and non-linearity and its interplay with health systems factors, using Uganda as a case study. Methods Literature reviews and interviews were conducted in two divisions of Kampala district with high neonatal mortality rates with mothers at antenatal clinics and at home, village health workers, community leaders, healthcare decision and policy makers, and frontline health workers from both public and private health facilities. Data analysis and brainstorming sessions were used to develop causal loop diagrams (CLDs) depicting the causes of neonatal mortality, which were validated by local and international stakeholders. Results We developed two CLDs for demand and supply side issues, depicting the range of factors associated with neonatal mortality such as maternal health, level of awareness of maternal and newborn health, and availability and quality of health services, among others. Further, the reinforcing and balancing feedback loops that resulted from this complexity were also examined. The potential high leverage points include special gender considerations to ensure that girls receive essential education, thereby increasing maternal literacy rates, improved socioeconomic status enabling mothers to keep healthy and utilise health services, improved supervision, and

  3. Methods of incorporating understanding of professional and ethical responsibility in the engineering curriculum and results from the Fundamentals of Engineering examination

    NASA Astrophysics Data System (ADS)

    Barry, Brock Edward

    This study evaluated the methods of incorporating professionalism and ethics in the engineering curriculum to determine the nature of the relationship between the curriculum model used and outcomes on a nationally administered, engineering-specific standardized examination. The study's population included engineering students enrolled at one of nine southeastern public universities between October 1996 and April 2005. The institutions are partners in the Multiple-Institution Database for Investigating Engineering Longitudinal Development (MIDFIELD) project. A mixed-methods (quantitative and qualitative) research program was designed and implemented. The qualitative aspects of the study focused on research questions related to the impetus and considerations given to curriculum changes made by the 23 engineering programs that participated in the study. The qualitative research questions were investigated using semi-structured interviews conducted with program representatives and evaluation of 49 ABET Self-Study accreditation documents. The curriculum model used by each of the participating programs were identified and defined for the period of the study and quantitatively compared to performance on the ethics section of the Fundamentals of Engineering (FE) Examination. The FE Examination is prepared and administered by the National Council for Engineering and Surveying (NCEES) and is the only nationally administered, engineering-specific, standardized assessment that measures performance on ABET-related criteria. A student-level dataset of subject scores was obtained for the FE Examination for all of the MIDFIELD programs. This study represents the first published attempt to utilize NCEES data for the purpose of rigorous educational research. Statistical techniques were used to evaluate the relationship between curriculum methods and examination performance. The findings indicate a statistical relationship, but a lack of structure between the amount of required

  4. The Radiation Belt Storm Probes Mission: Advancing Our Understanding of the Earth's Radiation Belts

    NASA Technical Reports Server (NTRS)

    Sibeck, David; Kanekal, Shrikanth; Kessel, Ramona; Fox, Nicola; Mauk, Barry

    2012-01-01

    We describe NASA's Radiation Belt Storm Probe (RBSP) mission, whose primary science objective is to understand, ideally to the point of predictability, the dynamics of relativistic electrons and penetrating ions in the Earth's radiation belts resulting from variable solar activity. The overarching scientific questions addressed include: 1. the physical processes that produce radiation belt enhancement events, 2. the dominant mechanisms for relativistic electron loss, and 3. how the ring current and other geomagnetic processes affect radiation belt behavior. The RBSP mission comprises two spacecraft which will be launched during Fall 2012 into low inclination lapping equatorial orbits. The orbit periods are about 9 hours, with perigee altitudes and apogee radial distances of 600 km and 5.8 RE respectively. During the two-year primary mission, the spacecraft orbits precess once around the Earth and lap each other twice in each local time quadrant. The spacecraft are each equipped with identical comprehensive instrumentation packages to measure, electrons, ions and wave electric and magnetic fields. We provide an overview of the RBSP mission, onboard instrumentation and science prospects and invite scientific collaboration.

  5. The Ease of Language Understanding (ELU) model: theoretical, empirical, and clinical advances

    PubMed Central

    Rönnberg, Jerker; Lunner, Thomas; Zekveld, Adriana; Sörqvist, Patrik; Danielsson, Henrik; Lyxell, Björn; Dahlström, Örjan; Signoret, Carine; Stenfelt, Stefan; Pichora-Fuller, M. Kathleen; Rudner, Mary

    2013-01-01

    Working memory is important for online language processing during conversation. We use it to maintain relevant information, to inhibit or ignore irrelevant information, and to attend to conversation selectively. Working memory helps us to keep track of and actively participate in conversation, including taking turns and following the gist. This paper examines the Ease of Language Understanding model (i.e., the ELU model, Rönnberg, 2003; Rönnberg et al., 2008) in light of new behavioral and neural findings concerning the role of working memory capacity (WMC) in uni-modal and bimodal language processing. The new ELU model is a meaning prediction system that depends on phonological and semantic interactions in rapid implicit and slower explicit processing mechanisms that both depend on WMC albeit in different ways. It is based on findings that address the relationship between WMC and (a) early attention processes in listening to speech, (b) signal processing in hearing aids and its effects on short-term memory, (c) inhibition of speech maskers and its effect on episodic long-term memory, (d) the effects of hearing impairment on episodic and semantic long-term memory, and finally, (e) listening effort. New predictions and clinical implications are outlined. Comparisons with other WMC and speech perception models are made. PMID:23874273

  6. Children are not just little adults: recent advances in understanding of diffuse intrinsic pontine glioma biology.

    PubMed

    Schroeder, Kristin M; Hoeman, Christine M; Becher, Oren J

    2014-01-01

    Diffuse intrinsic pontine glioma (DIPG) is a high-grade glioma that originates in the pons and is seen exclusively in children. Despite numerous efforts to improve treatment, DIPG remains incurable with 90% of children dying within 2 y of diagnosis, making it one of the leading causes of death in children with brain tumors. With the advent of new genomic tools, the genetic landscape of DIPG is slowly being unraveled. The most common genetic alterations include a K27M mutation in H3.3 or H3.1, which are found in up to 78% of DIPGs, whereas p53 mutations are found in up to 77%. Other recently discovered alterations include amplification of components of the receptor tyrosine kinase/Ras/phosphatidylinositol 3-kinase signaling pathway, particularly platelet-derived growth factor receptor A. Recapitulating such alterations, genetically engineered DIPG preclinical models have been developed, and DIPG xenograft models have also been established. Both models have strengths and weaknesses but can help with the prioritization of novel agents for clinical trials for children with DIPG. As we move forward, it is important that we continue to study the complex and unique biology of DIPG and develop improved preclinical models to increase our understanding of DIPG pathogenesis, allowing translation into successful therapies in the not too distant future. PMID:24192697

  7. Understanding how the leaf physiology of mangrove plants differs from fresh water plants: a fundamental step to use cellulose as a proxy for sea level rise

    NASA Astrophysics Data System (ADS)

    Ellsworth, P.; Sternberg, L. O.

    2010-12-01

    We studied the leaf water isotopic enrichment pattern of mangrove (halophytes) and hammock (glycophytes) plants as an attempt to explain why the δ18O of stem cellulose from mangrove and hammock species have no relationship with the δ18O of source water. A better understanding of leaf physiology of mangroves and its effect on the δ18O of stem cellulose is the first step in the process of developing an isotopic proxy for sea-level rise. Seawater is enriched in 18O relative to freshwater and this difference should be recorded in stem cellulose during its synthesis. Therefore, an enrichment in the oxygen isotope ratios of cellulose would reflect an increase in sea water levels. However, only ~40% of the 18O signal of stem cellulose comes from source water, the other ~60% comes from leaf water. Mangrove and hammock plants respond to environment conditions differently, which calls for a better understanding of leaf physiology and the ability to tease leaf physiolocal effects apart from the source water signal. We hypothesized that it’s likely that mangrove plants, having a greater proportion of water traveling simplastically, would have a longer water pathway from the xylem to the stomatal pore than hammock plants. According to the Peclet effect, this would cause lower isotopic enrichment of leaf water in mangroves compared to those of hammock species. This would explain previous measurements where δ18O of stem cellulose of mangrove was not as enriched as the expected. To test our hypothesis, a transect was selected across the 2 vegetation types (mangroves and hammocks). The parameters measured where: transpiration, temperature of the leaf, ambient temperature, relative humidity, δ18O of vapor, δ18O of stem water and δ18O of leaf water. With those parameters we calculated the effective length of the water pathway from the xylem to the stomatal pore. The results confirmed our hypothesis that mangrove leaves have a longer water pathway from the xylem to the

  8. Recent advances on the understanding of structural and composition evolution of LMR cathodes for Li-ion batteries

    SciTech Connect

    Yan, Pengfei; Zheng, Jianming; Xiao, Jie; Wang, Chong-Min; Zhang, Jiguang

    2015-06-08

    Lithium-rich, magnesium-rich (LMR) cathode materials have been regarded as one of the very promising cathodes for Li-ion battery applications. However, their practical application is still limited by several challenges, especially by their limited electrochemical stability rate capability. In this work, we present recent progresses on the understanding of the structural and composition evolution of LMR cathode materials with emphasis being placed on the correlation between structural/chemical evolution and electrochemical properties. In particular, using Li [Li0.2Ni0.2Mn0.6O2 as a typical example, we clearly illustrate the structural characteristics of the pristine materials and their dependence on the materials processing history, cycling induced structural degradation/chemical partition and their correlation with degradation of electrochemical performance. The fundamental understanding obtained in this work may also guide the design and preparation of new cathode materials based on ternary system of transitional metal oxide.

  9. Recent advances on the understanding of structural and composition evolution of LMR cathodes for Li-ion batteries

    DOE PAGESBeta

    Yan, Pengfei; Zheng, Jianming; Xiao, Jie; Wang, Chong-Min; Zhang, Jiguang

    2015-06-08

    Lithium-rich, magnesium-rich (LMR) cathode materials have been regarded as one of the very promising cathodes for Li-ion battery applications. However, their practical application is still limited by several challenges, especially by their limited electrochemical stability rate capability. In this work, we present recent progresses on the understanding of the structural and composition evolution of LMR cathode materials with emphasis being placed on the correlation between structural/chemical evolution and electrochemical properties. In particular, using Li [Li0.2Ni0.2Mn0.6O2 as a typical example, we clearly illustrate the structural characteristics of the pristine materials and their dependence on the materials processing history, cycling induced structuralmore » degradation/chemical partition and their correlation with degradation of electrochemical performance. The fundamental understanding obtained in this work may also guide the design and preparation of new cathode materials based on ternary system of transitional metal oxide.« less

  10. Recent Observational Advances in our Understanding of Magnetic Reconnection in Earth's Magnetosphere

    NASA Astrophysics Data System (ADS)

    Angelopoulos, V.

    2014-12-01

    The availability of multi-point observations through the ion diffusion region has provided a wealth of information on the workings of magnetic reconnection at the dayside magnetopause and at the nightside plasma sheet. Ion inertia and finite gyroradius result in clear Hall effects on ion inertial length scales that have been observed by single and multi-point spacecraft resulting in a fairly detailed understanding of that physics. The role of Hall dynamics on establishing the reconnection rate, and the outflow conditions is well understood. Electron violation of the frozen-in condition is much more subtle and rarely observed at the X-point; indirect evidence has been more frequently observed in parallel electric fields. The waves responsible for this violation and for resultant energy conversion are at the forefront of observational studies. The contraction of islands centered at multiple O-points could provide for rapid energy conversion. However, observations of in vivo FTEs at the dayside and classical plasmoids at the nightside, are rare even near the expected most probable location of reconnection. Rather, asymmetric proto-plasmoids and dipolarization (a.k.a reconnection) fronts at the nightside signify distinctly different evolution of the reconnection geometry from that of X and O points. Operating within meso-scale (1-3Re) flows the inherently kinetic (at electron inertial scales embeded in ion inertial scale current systems) processes at such fronts play a significant role in the dynamics and drive global magnetospheric energy conversion and flux transport. Recent studies suggest that the entire magnetosphere is, in fact, connected front-to-back by reconnection pulses resulting in meso-scale flows. The upcoming Heliophysics System Observatory, motivated by the launch of MMS and the coordinated observations of THEMIS, ARTEMIS, Van Allen probes and other space and ground assets will answer key questions on this subject locally, regionally and globally.

  11. Recent Advances in Understanding Radiation Belt Dynamics in the Earth's Inner Zone and Slot Region

    NASA Astrophysics Data System (ADS)

    Li, X.

    2015-12-01

    Comprehensive measurements of the inner belt protons from the Relativistic Electron and Proton Telescope (REPT) onboard Van Allen Probes, in a geo-transfer-like orbit, revealed new features of inner belt protons in terms of their spectrum distribution, spatial distribution, pitch angle distribution, and their different source populations. Concurrent measurements from the Relativistic Electron and Proton Telescope integrated little experiment (REPTile) on board Colorado Student Space Weather Experiment (CSSWE) CubeSat, in a highly inclined low Earth orbit, and REPT demonstrated that there exist sub-MeV electrons in the inner belt and their flux level is orders of magnitude higher than the background associated with the inner belt protons, while higher energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Analysis on sub-MeV electrons data in the inner belt and slot region from the Magnetic Electron Ion Spectrometer (MagEIS) on board Van Allen Probes revealed rather complicated pitch angle distribution of these energetic electrons, with the 90 deg-minimum (butterfly) pitch angle distribution dominating near the magnetic equator. Furthermore, it is clearly shown from MagEIS measurements that 10s - 100s keV electrons are commonly seen penetrating into the inner belt region during geomagnetic active times while protons of similar energies are hardly seen there. These are part of a summary of the most recent measurements and understanding of the dynamics of energetic particles in the inner zone and slot region to be exhibited and discussed in this presentation.

  12. Recent advances in understanding the assembly and repair of photosystem II

    PubMed Central

    Nixon, Peter J.; Michoux, Franck; Yu, Jianfeng; Boehm, Marko; Komenda, Josef

    2010-01-01

    Background Photosystem II (PSII) is the light-driven water:plastoquinone oxidoreductase of oxygenic photosynthesis and is found in the thylakoid membrane of chloroplasts and cyanobacteria. Considerable attention is focused on how PSII is assembled in vivo and how it is repaired following irreversible damage by visible light (so-called photoinhibition). Understanding these processes might lead to the development of plants with improved growth characteristics especially under conditions of abiotic stress. Scope Here we summarize recent results on the assembly and repair of PSII in cyanobacteria, which are excellent model organisms to study higher plant photosynthesis. Conclusions Assembly of PSII is highly co-ordinated and proceeds through a number of distinct assembly intermediates. Associated with these assembly complexes are proteins that are not found in the final functional PSII complex. Structural information and possible functions are beginning to emerge for several of these ‘assembly’ factors, notably Ycf48/Hcf136, Psb27 and Psb28. A number of other auxiliary proteins have been identified that appear to have evolved since the divergence of chloroplasts and cyanobacteria. The repair of PSII involves partial disassembly of the damaged complex, the selective replacement of the damaged sub-unit (predominantly the D1 sub-unit) by a newly synthesized copy, and reassembly. It is likely that chlorophyll released during the repair process is temporarily stored by small CAB-like proteins (SCPs). A model is proposed in which damaged D1 is removed in Synechocystis sp. PCC 6803 by a hetero-oligomeric complex composed of two different types of FtsH sub-unit (FtsH2 and FtsH3), with degradation proceeding from the N-terminus of D1 in a highly processive reaction. It is postulated that a similar mechanism of D1 degradation also operates in chloroplasts. Deg proteases are not required for D1 degradation in Synechocystis 6803 but members of this protease family might play a

  13. Recent Advances in Understanding the Sources of Methylmercury to Coastal Waters

    NASA Astrophysics Data System (ADS)

    Mason, R. P.; Balcom, P.; Chen, C.; Gosnell, K. J.; Jonsson, S.; Mazrui, N.; Ortiz, V.; Seelen, E.; Schartup, A. T.; Sunderland, E. M.

    2015-12-01

    Understanding the sources of methylmercury (MeHg) to the food chain in coastal waters is important given the related health concerns from consumption of seafood containing elevated MeHg. While water column dissolved or particulate MeHg is the best predictor of bioaccumulation into pelagic organisms in coastal waters, there is debate concerning the dominant sources of MeHg to the water column, and how the relative importance of these sources vary with ecosystem characteristics. Potential sources include both external inputs from the watershed and offshore waters and internal sources (net methylation in sediments and the associated flux of MeHg to the water column and/or net MeHg production in the water column). We will report the results from our various studies in estuarine and coastal waters which have examined the distribution and partitioning of sediment and water column MeHg, and its formation and degradation, across a geographic range from Labrador, Canada to the Chesapeake Bay, USA. The ecosystems studied vary from shallow estuarine bays to deeper systems, and from salt wedge to tidally-dynamic systems. Additionally, both pristine and contaminated environments were examined. The studies examined the factors controlling the net production of MeHg in sediments, and in our more recent work, the potential formation of MeHg in the oxic water column of coastal waters. Sediment measurements (core and grab samples) included both solid phase and porewater MeHg and total mercury (HgT) and important ancillary parameters. Water column parameters included dissolved and particulate MeHg and HgT, TSS, nutrients, and DOC. Stable Hg isotope tracer incubations were used to assess the degree of methylation and demethylation in sediments and surface waters. Average suspended particle MeHg ranged from <5 to 120 pmol/g, and was 1-8% of HgT across sites. Mass balance estimates provide insights into the importance of external MeHg sources to coastal waters. We will use the

  14. Advancing our understanding of plant adaptation to metal polluted environments - new insights from Biscutella laevigata

    NASA Astrophysics Data System (ADS)

    Babst-Kostecka, Alicja; Waldmann, Patrik; Frérot, Hélène; Vollenweider, Pierre

    2016-04-01

    The legacy of industrial pollution alters ecosystems, particularly at post-mining sites where metal trace elements have created toxic conditions that trigger rapid plant adaptation. Apart from the purely scientific merits, in-depth knowledge of the mechanisms underlying plant adaptation to metal contamination is beneficial for the economic and societal sectors because of its application in bioengineering (e.g. phytoremediation or biofortification). An important process is the evolution and/or enhancement of metal tolerance, a trait that has predominantly been studied by applying acute metal stress on species that allocate large quantities of certain metals to their foliage (so-called hyperaccumulators). As the vast majority of vascular plants does not hyperaccumulate metals, more efforts are needed to investigate non-hyperaccumulating species and thereby broaden understanding of biological mechanisms underlying metal tolerance. The pseudometallophyte Biscutella laevigata has shown potential in this respect, but its characteristics are insufficiently understood. We determined the zinc tolerance level and various plant responses to environmentally relevant zinc concentrations in ten metallicolous and non-metallicolous B. laevigata populations. In a two-phase hydroponic experiment, we scored multiple morphological and physiological traits (e.g. biomass, visible stress symptoms, element content in foliage) and assessed phenotypic variability within plant families. The structure of these quantitative traits was compared to that of neutral molecular markers to test, whether natural selection caused population differentiation in zinc tolerance. While all genotypes were tolerant compared to a zinc sensitive reference species, we found congruent trends toward higher tolerance in metallicolous compared to non-metallicolous plants. We identified the most indicative parameters for these differences and find that enhanced zinc tolerance in metallicolous populations is driven by

  15. Understanding what the public know and value about geoheritage sites in order to advance Earth science literacy

    NASA Astrophysics Data System (ADS)

    Vye, E. C.; Rose, W. I.

    2013-12-01

    With its impressive geology and rich cultural history, Michigan's Keweenaw Peninsula is ideally suited for Earth science education and geotourism initiatives, such as a Geopark. Geologic events that have shaped this region can be interpreted in such a way as to engage learners, not only through an intellectual connection to Earth science subject matter, but also through an emotional connection via culture, history, and sense of place. The notion that landscape is special because it is the sum total of all the interacting earth systems, including people as part of the biosphere, can be used to drive these initiatives as they affect one personally. It is speculated that most people in the Keweenaw have a basic understanding of the local cultural history and some understanding of geology. Advanced awareness and understanding of the geological significance of the Keweenaw stands to greatly enrich our community's sense of place and desire to advance further education and geotourism initiatives. It is anticipated that these initiatives will ultimately lead to increased Earth science literacy and understanding and recognition of one's own environs. This will aid in the further development of publications, teaching media, trails info, on-site museums, etc. Although the community has embraced geo-outreach thus far, it is germane to know what people value, what they know of the geology and how they connect to place. Results from semi-structured interviews administered with the aim and focus of determining what places are special to people, why they are special and how they formed will be presented in this paper. The results from this research will be used to direct the creation and continued development of geologic interpretation of our region. It is hoped that this understanding will reveal common misconceptions that can be used to improve interpretive material that not only addresses misconceptions but also connects the immediate past with the deep geologic past of the

  16. Analysis of the Durability of PEM FC Membrane Electrode Assemblies in Automotive Applications through the Fundamental Understanding of Membrane and MEA Degradation Pathways

    SciTech Connect

    Perry, Randal L.

    2013-10-31

    The Project focused on mitigation of degradation processes on membrane electrode assemblies. The approach was to develop a model to improve understanding of the mechanisms, and to use it to focus mitigation strategies. The detailed effects of various accelerated stress tests (ASTs) were evaluated to determine the best subset to use in model development. A combination of ASTs developed by the Fuel Cell Commercialization Conference of Japan and the Fuel Cell Tech Team were selected for use. The ASTs were compared by measuring effects on performance, running in-situ diagnostics, and performing microscopic analyses of the membrane electrode assemblies after the stress tests were complete. Nissan ran FCCJ AST protocols and performed in situ and ex-situ electrochemical testing. DuPont ran FCTT and USFCC AST protocols, performed scanning and transmission electron microscopy and ran in-situ electrochemical tests. Other ex-situ testing was performed by IIT, along with much of the data analysis and model development. These tests were then modified to generate time-dependent data of the degradation mechanisms. Three different catalyst types and four membrane variants were then used to generate data for a theoretically-based degradation model. An important part of the approach was to use commercially available materials in the electrodes and membranes made in scalable semiworks processes rather than lab-based materials. This constraint ensured all materials would be practicable for full-scale testing. The initial model for the electrode layer was tested for internal consistency and agreement with the data. A Java-based computer application was developed to analyze the time-dependent AST data using polarization curves with four different cathode gas feeds and generate model parameters. Data showed very good reproducibility and good consistency as cathode catalyst loadings were varied. At the point of termination of the project, a basic electrode model was in hand with several

  17. Ethics fundamentals.

    PubMed

    Chambers, David W

    2011-01-01

    Ethics is about studying the right and the good; morality is about acting as one should. Although there are differences among what is legal, charitable, professional, ethical, and moral, these desirable characteristics tend to cluster and are treasured in dentistry. The traditional approach to professionalism in dentistry is based on a theory of biomedical ethics advanced 30 years ago. Known as the principles approach, general ideals such as respect for autonomy, nonmaleficence, beneficence, justice, and veracity, are offered as guides. Growth in professionalism consists in learning to interpret the application of these principles as one's peers do. Moral behavior is conceived as a continuous cycle of sensitivity to situations requiring moral response, moral reasoning, the moral courage to take action when necessary, and integration of habits of moral behavior into one's character. This essay is the first of two papers that provide the backbone for the IDEA Project of the College--an online, multiformat, interactive "textbook" of ethics for the profession. PMID:22263371

  18. Fundamental bioprocessing research for coal applications

    SciTech Connect

    Kaufman, E.N.

    1996-06-01

    The purpose of this program is to gain a fundamental understanding and sound scientific technical basis for evaluating the potential roles of innovative bioprocessing concepts for the utilization and conversion of coal. The aim is to explore the numerous ways in which advanced biological processes and techniques can open new opportunities for coal utilization or can replace more conventional techniques by use of milder conditions with less energy consumption or loss. There are several roles where biotechnology is likely to be important in coal utilization and conversion. These include potential bioprocessing systems such.

  19. Recent advances in the understanding of endometriosis: the role of inflammatory mediators in disease pathogenesis and treatment

    PubMed Central

    Nothnick, Warren; Alali, Zahraa

    2016-01-01

    In this review, we focus on recent advancements in our understanding of the roles of inflammatory mediators in endometriosis pathophysiology and the potential for improved therapies based upon targeting these pathways. We review the association between endometriosis and inflammation and the initial promise of anti-tumor necrosis factor therapies based upon experimental evidence, and how and why these studies have not translated to the clinic. We then discuss emerging data on the role of inter-relationship among macrophage migration inhibitory factor, prostaglandin E 2, and estrogen receptor-beta, and the potential utility of targeting these factors in endometriosis treatment. In doing so, we highlight the strengths and discuss the current research on identification of novel, anti-inflammatory-based therapy and the necessity to expand experimental endpoints to include clinically relevant measures when assessing the efficacy of potential new therapies for endometriosis. PMID:26949527

  20. Advancing Our Understanding of the Link between Statistical Learning and Language Acquisition: The Need for Longitudinal Data

    PubMed Central

    Arciuli, Joanne; Torkildsen, Janne von Koss

    2012-01-01

    Mastery of language can be a struggle for some children. Amongst those that succeed in achieving this feat there is variability in proficiency. Cognitive scientists remain intrigued by this variation. A now substantial body of research suggests that language acquisition is underpinned by a child’s capacity for statistical learning (SL). Moreover, a growing body of research has demonstrated that variability in SL is associated with variability in language proficiency. Yet, there is a striking lack of longitudinal data. To date, there has been no comprehensive investigation of whether a capacity for SL in young children is, in fact, associated with language proficiency in subsequent years. Here we review key studies that have led to the need for this longitudinal research. Advancing the language acquisition debate via longitudinal research has the potential to transform our understanding of typical development as well as disorders such as autism, specific language impairment, and dyslexia. PMID:22969746

  1. Role of extrahepatic UDP-glucuronosyltransferase 1A1: Advances in understanding breast milk-induced neonatal hyperbilirubinemia.

    PubMed

    Fujiwara, Ryoichi; Maruo, Yoshihiro; Chen, Shujuan; Tukey, Robert H

    2015-11-15

    Newborns commonly develop physiological hyperbilirubinemia (also known as jaundice). With increased bilirubin levels being observed in breast-fed infants, breast-feeding has been recognized as a contributing factor for the development of neonatal hyperbilirubinemia. Bilirubin undergoes selective metabolism by UDP-glucuronosyltransferase (UGT) 1A1 and becomes a water soluble glucuronide. Although several factors such as gestational age, dehydration and weight loss, and increased enterohepatic circulation have been associated with breast milk-induced jaundice (BMJ), deficiency in UGT1A1 expression is a known cause of BMJ. It is currently believed that unconjugated bilirubin is metabolized mainly in the liver. However, recent findings support the concept that extrahepatic tissues, such as small intestine and skin, contribute to bilirubin glucuronidation during the neonatal period. We will review the recent advances made towards understanding biological and molecular events impacting BMJ, especially regarding the role of extrahepatic UGT1A1 expression. PMID:26342858

  2. Advanced simulation technology used to reduce accident rates through a better understanding of human behaviors and human perception

    NASA Astrophysics Data System (ADS)

    Manser, Michael P.; Hancock, Peter A.

    1996-06-01

    Human beings and technology have attained a mutually dependent and symbiotic relationship. It is easy to recognize how each depends on the other for survival. It is also easy to see how technology advances due to human activities. However, the role technology plays in advancing humankind is seldom examined. This presentation examines two research areas where the role of advanced visual simulation systems play an integral and essential role in understanding human perception and behavior. The ultimate goal of this research is the betterment of humankind through reduced accident and death rates in transportation environments. The first research area examined involved the estimation of time-to-contact. A high-fidelity wrap-around simulator (RAS) was used to examine people's ability to estimate time-to- contact. The ability of people to estimate the amount of time before an oncoming vehicle will collide with them is a necessary skill for avoiding collisions. A vehicle approached participants at one of three velocities, and while en route to the participant, the vehicle disappeared. The participants' task was to respond when they felt the accuracy of time-to-contact estimates and the practical applications of the result. The second area of research investigates the effects of various visual stimuli on underground transportation tunnel walls for the perception of vehicle speed. A RAS is paramount in creating visual patterns in peripheral vision. Flat-screen or front-screen simulators do not have this ability. Results are discussed in terms of speed perception and the application of these results to real world environments.

  3. Fundamental experiments in velocimetry

    SciTech Connect

    Briggs, Matthew Ellsworth; Hull, Larry; Shinas, Michael

    2009-01-01

    One can understand what velocimetry does and does not measure by understanding a few fundamental experiments. Photon Doppler Velocimetry (PDV) is an interferometer that will produce fringe shifts when the length of one of the legs changes, so we might expect the fringes to change whenever the distance from the probe to the target changes. However, by making PDV measurements of tilted moving surfaces, we have shown that fringe shifts from diffuse surfaces are actually measured only from the changes caused by the component of velocity along the beam. This is an important simplification in the interpretation of PDV results, arising because surface roughness randomizes the scattered phases.

  4. Recent Advances in Understanding the Molecular Mechanisms Regulating the Root System Response to Phosphate Deficiency in Arabidopsis.

    PubMed

    Bouain, Nadia; Doumas, Patrick; Rouached, Hatem

    2016-08-01

    Phosphorus (P) is an essential macronutrient for plant growth and development. Inorganic phosphate (Pi) is the major form of P taken up from the soil by plant roots. It is well established that under Pi deficiency condition, plant roots undergo striking morphological changes; mainly a reduction in primary root length while increase in lateral root length as well as root hair length and density. This typical phenotypic change reflects complex interactions with other nutrients such as iron, and involves the activity of a large spectrum of plant hormones. Although, several key proteins involved in the regulation of root growth under Pi-deficiency have been identified in Arabidopsis, how plants adapt roots system architecture in response to Pi availability remains an open question. In the current post-genomic era, state of the art technologies like high-throughput phenotyping and sequencing platforms,"omics" methods, together with the widespread use of system biology and genome-wide association studies will help to elucidate the genetic architectures of root growth on different Pi regimes. It is clear that the large-scale characterization of molecular systems will improve our understanding of nutrient stress phenotype and biology. Herein, we summarize the recent advances and future directions towards a better understanding of Arabidopsis root developmental programs functional under Pi deficiency. Such a progress is necessary to devise strategies to improve the Pi use efficiency in plants that is an important issue for agriculture. PMID:27499680

  5. Understanding the Racial and Ethnic Differences in Cost and Mortality Among Advanced Stage Prostate Cancer Patients (STROBE).

    PubMed

    Chhatre, Sumedha; Bruce Malkowicz, Stanley; Sanford Schwartz, J; Jayadevappa, Ravishankar

    2015-08-01

    The aims of the study were to understand the racial/ethnic differences in cost of care and mortality in Medicare elderly with advanced stage prostate cancer.This retrospective, observational study used SEER-Medicare data. Cohort consisted of 10,509 men aged 66 or older and diagnosed with advanced-stage prostate cancer between 2001and 2004. The cohort was followed retrospectively up to 2009. Racial/ethnic variation in cost was analyzed using 2 part-models and quantile regression. Step-wise GLM log-link and Cox regression was used to study the association between race/ethnicity and cost and mortality. Propensity score approach was used to minimize selection bias.Pattern of cost and mortality varies between racial/ethnic groups. Compared with other racial/ethnic groups, non-Hispanic white patients had higher unadjusted costs in treatment and follow-up phases. Quintile regression results indicated that in treatment phase, Hispanics had higher costs in the 95th quantile and non-Hispanic blacks had lower cost in the 95th quantile, compared with non-Hispanic white men. In terminal phase non-Hispanic blacks and Hispanics had higher cost. After controlling for treatment, all-cause and prostate cancer-specific mortality was not significant for non-Hispanic black men, compared with non-Hispanic white men. However, for Asians, mortality remained significantly lower compared with non-Hispanic white men.In conclusion, relationship between race/ethnicity, cost of care, and mortality is intricate. For non-Hispanic black men, disparity in mortality can be attributed to treatment differences. To reduce racial/ethnic disparities in prostate cancer care and outcomes, tailored policies to address underuse, overuse, and misuse of treatment and health services are necessary. PMID:26266389

  6. Fundamental studies on cavitation melt processing

    NASA Astrophysics Data System (ADS)

    Tzanakis, I.; Hodnett, M.; Lebon, G. S. B.; Eskin, D. G.; Pericleous, K.

    2016-05-01

    The application of ultrasound to industrial casting processes has attracted research interest during the last 50 years. However, the transfer and scale-up of this advanced and promising technology to industry has been hindered by difficulties in treating large volumes of liquid metal due to the lack of understanding of certain fundamentals. In the current study experimental results on ultrasonic processing in deionised water and in liquid aluminium (Al) are reported. Cavitation activity was determined in both liquid environments and acoustic pressures were successfully measured using an advanced high-temperature cavitometer sensor. Results showed that highest cavitation intensity in the liquid bulk is achieved at lower amplitudes of the sonotrode tip than the maximum available, suggesting nonlinearity in energy transfer to the liquid, while the location of the sonotrode is seen to substantially affect cavitation activity within the liquid. Estimation of real-time acoustic pressures distributed inside a crucible with liquid Al was performed for the first time.

  7. Fundamentals and recent advances in X-ray micro computed tomography (microCT) applied on thermal-fluid dynamics and multiphase flows

    NASA Astrophysics Data System (ADS)

    Santini, Maurizio

    2015-11-01

    X-ray computed tomography (CT) is a well-known technique nowadays, since its first practical application by Sir. G. Hounsfield (Nobel price for medicine 1979) has continually benefited from optimising improvements, especially in medical applications. Indeed, also application of CT in various engineering research fields provides fundamental informations on a wide range of applications, considering that the technique is not destructive, allowing 3D visualization without perturbation of the analysed material. Nowadays, it is technologically possible to design and realize an equipment that achieve a micrometric resolution and even improve the sensibility in revealing differences in materials having very radiotransparency, allowing i.e. to distinguish between different fluids (with different density) or states of matter (like with two-phase flows). At the University of Bergamo, a prototype of an X-ray microCT system was developed since 2008, so being fully operative from 2012, with specific customizations for investigations in thermal-fluid dynamics and multiphase flow researches. A technical session held at the UIT International Conference in L'Aquila (Italy), at which this paper is referring, has presented some microCT fundamentals, to allow the audience to gain basics to follow the “fil-rouge” that links all the instrumentation developments, till the recent applications. Hereinafter are reported some applications currently developed at Bergamo University at the X-ray computed micro-tomography laboratory.

  8. Fundamentals of Structural Geology

    NASA Astrophysics Data System (ADS)

    Pollard, David D.; Fletcher, Raymond C.

    2005-09-01

    Fundamentals of Structural Geology provides a new framework for the investigation of geological structures by integrating field mapping and mechanical analysis. Assuming a basic knowledge of physical geology, introductory calculus and physics, it emphasizes the observational data, modern mapping technology, principles of continuum mechanics, and the mathematical and computational skills, necessary to quantitatively map, describe, model, and explain deformation in Earth's lithosphere. By starting from the fundamental conservation laws of mass and momentum, the constitutive laws of material behavior, and the kinematic relationships for strain and rate of deformation, the authors demonstrate the relevance of solid and fluid mechanics to structural geology. This book offers a modern quantitative approach to structural geology for advanced students and researchers in structural geology and tectonics. It is supported by a website hosting images from the book, additional colour images, student exercises and MATLAB scripts. Solutions to the exercises are available to instructors. The book integrates field mapping using modern technology with the analysis of structures based on a complete mechanics MATLAB is used to visualize physical fields and analytical results and MATLAB scripts can be downloaded from the website to recreate textbook graphics and enable students to explore their choice of parameters and boundary conditions The supplementary website hosts color images of outcrop photographs used in the text, supplementary color images, and images of textbook figures for classroom presentations The textbook website also includes student exercises designed to instill the fundamental relationships, and to encourage the visualization of the evolution of geological structures; solutions are available to instructors

  9. From technological advances to biological understanding: The main steps toward high-precision RT in breast cancer.

    PubMed

    Leonardi, Maria Cristina; Ricotti, Rosalinda; Dicuonzo, Samantha; Cattani, Federica; Morra, Anna; Dell'Acqua, Veronica; Orecchia, Roberto; Jereczek-Fossa, Barbara Alicja

    2016-10-01

    Radiotherapy improves local control in breast cancer (BC) patients which increases overall survival in the long term. Improvements in treatment planning and delivery and a greater understanding of BC behaviour have laid the groundwork for high-precision radiotherapy, which is bound to further improve the therapeutic index. Precise identification of target volumes, better coverage and dose homogeneity have had a positive impact on toxicity and local control. The conformity of treatment dose due to three-dimensional radiotherapy and new techniques such as intensity modulated radiotherapy makes it possible to spare surrounding normal tissue. The widespread use of dose-volume constraints and histograms have increased awareness of toxicity. Real time image guidance has improved geometric precision and accuracy, together with the implementation of quality assurance programs. Advances in the precision of radiotherapy is also based on the choice of the appropriate fractionation and approach. Adaptive radiotherapy is not only a technical concept, but is also a biological concept based on the knowledge that different types of BC have distinctive patterns of locoregional spread. A greater understanding of cancer biology helps in choosing the treatment best suited to a particular situation. Biomarkers predictive of response play a crucial role. The combination of radiotherapy with molecular targeted therapies may enhance radiosensitivity, thus increasing the cytotoxic effects and improving treatment response. The appropriateness of an alternative fractionation, partial breast irradiation, dose escalating/de-escalating approaches, the extent of nodal irradiation have been examined for all the BC subtypes. The broadened concept of adaptive radiotherapy is vital to high-precision treatments. PMID:27542556

  10. Utilizing LiDAR Datasets From Experimental Watersheds to Advance Ecohydrological Understanding in Seasonally Snow-Covered Forests

    NASA Astrophysics Data System (ADS)

    Harpold, A. A.; Broxton, P. D.; Guo, Q.; Barlage, M. J.; Gochis, D. J.

    2014-12-01

    The Western U.S. is strongly reliant on snowmelt from forested areas for ecosystem services and downstream populations. The ability to manage water resources from snow-covered forests faces major challenges from drought, disturbance, and regional changes in climate. An exciting avenue for improving ecohydrological process understanding is Light Detection and Ranging (LiDAR) because the technology simultaneously observes topography, forest properties, and snow/ice at high-resolution (<10 cm) and over large extents (>100 km2). The availability and quality of LiDAR datasets is increasing rapidly, however they remain under-utilized for process-based ecohydrology investigations. This presentation will illustrate how LiDAR datasets from the Critical Zone Observatory (CZO) network have been applied to advance ecohydrological understanding through direct empirical analysis, as well as model parameterization and verification. Direct analysis of the datasets has proved fruitful for pre- and post-disturbance snow distribution estimates and interpreting in-situ snow depth measurements across sites. In addition, we illustrate the potential value of LiDAR to parameterize and verify of physical models with two examples. First, we use LiDAR to parameterize a land surface model, Noah multi-parameterization (Noah-MP), to investigate the sensitivity of modeled water and energy fluxes to high-resolution forest information. Second, we present a Snow Physics and Laser Mapping (SnowPALM) model that is parameterized with LiDAR information at its native 1-m scale. Both modeling studies demonstrate the value of LiDAR for representing processes with greater fidelity. More importantly, the increased model fidelity led to different estimates of water and energy fluxes at larger, watershed scales. Creating a network of experimental watersheds with LiDAR datasets offers the potential to test theories and models in previously unexplored ways.

  11. Finite difference simulations of seismic wave propagation for understanding earthquake physics and predicting ground motions: Advances and challenges

    NASA Astrophysics Data System (ADS)

    Aochi, Hideo; Ulrich, Thomas; Ducellier, Ariane; Dupros, Fabrice; Michea, David

    2013-08-01

    Seismic waves radiated from an earthquake propagate in the Earth and the ground shaking is felt and recorded at (or near) the ground surface. Understanding the wave propagation with respect to the Earth's structure and the earthquake mechanisms is one of the main objectives of seismology, and predicting the strong ground shaking for moderate and large earthquakes is essential for quantitative seismic hazard assessment. The finite difference scheme for solving the wave propagation problem in elastic (sometimes anelastic) media has been more widely used since the 1970s than any other numerical methods, because of its simple formulation and implementation, and its easy scalability to large computations. This paper briefly overviews the advances in finite difference simulations, focusing particularly on earthquake mechanics and the resultant wave radiation in the near field. As the finite difference formulation is simple (interpolation is smooth), an easy coupling with other approaches is one of its advantages. A coupling with a boundary integral equation method (BIEM) allows us to simulate complex earthquake source processes.

  12. Long-Term Transcriptional Consequences of Drug Exposure as Cues to Understand Vulnerability to Relapse: Advances and Perspectives.

    PubMed

    Becker, Jerome A J; Le Merrer, Julie

    2016-09-01

    Quitting drug abuse represents a true challenge for addicted individuals because of the highly persistent vulnerability to relapse. Identifying long-lasting, drug-induced alterations in the brain-including at the transcriptome level-that underlie such vulnerability appears invaluable to improve relapse prevention. Despite substantial technological developments and research effort, however, the picture of drug-induced adaptations provided by high-throughput transcriptomics remains frustratingly partial, notably because of methodological issues. Major advances were made, however, regarding the time course and specificity of long-term transcriptional consequences of drug exposure as well as the recruitment of small, noncoding mRNAs (or miRNAs [microRNAs]) that were previously undetectable. Most importantly, high-throughput studies have benefited from systems biology approaches and shifted their interest toward regulations within functional gene networks rather than individual changes. Such network-based gene discovery approaches have proven informative to delineate the physiological processes, cellular signaling pathways, and neuronal populations altered by drug exposure. Provided the high-throughput effort will be pursued, together with the development of adapted bioinformatics tools, addiction transcriptomics should progressively integrate data across multiple scales (from epigenome to protein), allowing a better understanding of the genetics of drug abuse and opening novel therapeutic trails. PMID:27588526

  13. Hydrological partitioning in the critical zone: Recent advances and opportunities for developing transferable understanding of water cycle dynamics

    NASA Astrophysics Data System (ADS)

    Brooks, Paul D.; Chorover, Jon; Fan, Ying; Godsey, Sarah E.; Maxwell, Reed M.; McNamara, James P.; Tague, Christina

    2015-09-01

    Hydrology is an integrative discipline linking the broad array of water-related research with physical, ecological, and social sciences. The increasing breadth of hydrological research, often where subdisciplines of hydrology partner with related sciences, reflects the central importance of water to environmental science, while highlighting the fractured nature of the discipline itself. This lack of coordination among hydrologic subdisciplines has hindered the development of hydrologic theory and integrated models capable of predicting hydrologic partitioning across time and space. The recent development of the concept of the critical zone (CZ), an open system extending from the top of the canopy to the base of groundwater, brings together multiple hydrological subdisciplines with related physical and ecological sciences. Observations obtained by CZ researchers provide a diverse range of complementary process and structural data to evaluate both conceptual and numerical models. Consequently, a cross-site focus on "critical zone hydrology" has potential to advance the discipline of hydrology and to facilitate the transition of CZ observatories into a research network with immediate societal relevance. Here we review recent work in catchment hydrology and hydrochemistry, hydrogeology, and ecohydrology that highlights a common knowledge gap in how precipitation is partitioned in the critical zone: "how is the amount, routing, and residence time of water in the subsurface related to the biogeophysical structure of the CZ?" Addressing this question will require coordination among hydrologic subdisciplines and interfacing sciences, and catalyze rapid progress in understanding current CZ structure and predicting how climate and land cover changes will affect hydrologic partitioning.

  14. Advancing current approaches to disease management evaluation: capitalizing on heterogeneity to understand what works and for whom

    PubMed Central

    2013-01-01

    Background Evaluating large-scale disease management interventions implemented in actual health care settings is a complex undertaking for which universally accepted methods do not exist. Fundamental issues, such as a lack of control patients and limited generalizability, hamper the use of the ‘gold-standard’ randomized controlled trial, while methodological shortcomings restrict the value of observational designs. Advancing methods for disease management evaluation in practice is pivotal to learn more about the impact of population-wide approaches. Methods must account for the presence of heterogeneity in effects, which necessitates a more granular assessment of outcomes. Methods This paper introduces multilevel regression methods as valuable techniques to evaluate ‘real-world’ disease management approaches in a manner that produces meaningful findings for everyday practice. In a worked example, these methods are applied to retrospectively gathered routine health care data covering a cohort of 105,056 diabetes patients who receive disease management for type 2 diabetes mellitus in the Netherlands. Multivariable, multilevel regression models are fitted to identify trends in clinical outcomes and correct for differences in characteristics of patients (age, disease duration, health status, diabetes complications, smoking status) and the intervention (measurement frequency and range, length of follow-up). Results After a median one year follow-up, the Dutch disease management approach was associated with small average improvements in systolic blood pressure and low-density lipoprotein, while a slight deterioration occurred in glycated hemoglobin. Differential findings suggest that patients with poorly controlled diabetes tend to benefit most from disease management in terms of improved clinical measures. Additionally, a greater measurement frequency was associated with better outcomes, while longer length of follow-up was accompanied by less positive results

  15. Advancing understanding of the fluvial export of organic matter through high-resolution profiling of dissolved organic carbon.

    NASA Astrophysics Data System (ADS)

    Waldron, S.; Drew, S.; Gilvear, D.; Murray, H.; Heal, K.

    2012-04-01

    Quantifying the natural variation (complexity) of a system remains an enduring scientific challenge in better understanding controls on surface water quality. This characterisation is needed in order to reveal controlling processes, such as dilution, and also to identify unusual load profiles. In trying to capture that natural variation we still rely largely on concentration time series (and associated export budgets) generated from manual spot sampling, or from samples collected by autosamplers - approaches which are unlikely to provide the high temporal resolution of parameter concentration required. Now however, advances in sensor technology are helping us address this challenge. Here we present detailed dissolved organic carbon (DOC) export profiles from a small upland river (9.4 km sq.), generated since June 2011 by semi-continuous logging of UV-vis absorption (200-750 nm, every 2.5 nm) every 30 minutes. Observed increases in the concentration of the DOC, [DOC], in freshwaters have prompted significant research to understand the cause and consequences of increased export: higher levels of DOC require additional water purification of potable sources; increased aquatic export may represent a reduction in terrestrial C-soil sequestration; changes in light penetration can affect the heterotrophic / autotrophic balance in surface waters and this has consequences for the food web structure; increased aquatic export may also result in increased carbon dioxide evasion. Additionally, C export is often linked to nutrient export: we have observed statistically significant stoichiometric relationships between DOC and soluble reactive phosphorus (SRP) concentrations, thus understanding better this parameters offers insight into export of other nutrient and the source of material from which these dissolved compounds are produced; this may be particulate. Our Scottish study site is interesting because there are multiple processes that can contribute to DOC and other nutrient

  16. Fundamentals and applications of gas hydrates.

    PubMed

    Koh, Carolyn A; Sloan, E Dendy; Sum, Amadeu K; Wu, David T

    2011-01-01

    Fundamental understanding of gas hydrate formation and decomposition processes is critical in many energy and environmental areas and has special importance in flow assurance for the oil and gas industry. These areas represent the core of gas hydrate applications, which, albeit widely studied, are still developing as growing fields of research. Discovering the molecular pathways and chemical and physical concepts underlying gas hydrate formation potentially can lead us beyond flowline blockage prevention strategies toward advancing new technological solutions for fuel storage and transportation, safely producing a new energy resource from natural deposits of gas hydrates in oceanic and arctic sediments, and potentially facilitating effective desalination of seawater. The state of the art in gas hydrate research is leading us to new understanding of formation and dissociation phenomena that focuses on measurement and modeling of time-dependent properties of gas hydrates on the basis of their well-established thermodynamic properties. PMID:22432618

  17. Recent advances in bio-logging science: Technologies and methods for understanding animal behaviour and physiology and their environments

    NASA Astrophysics Data System (ADS)

    Evans, K.; Lea, M.-A.; Patterson, T. A.

    2013-04-01

    The deployment of an ever-evolving array of animal-borne telemetry and data logging devices is rapidly increasing our understanding of the movement, behaviour and physiology of a variety species and the complex, and often highly dynamic, environments they use and respond to. The rapid rate at which new technologies, improvements to current technologies and new analytical techniques are being developed has meant that movements, behaviour and physiological processes are being quantified at finer spatial and temporal scales than ever before. The Fourth International Symposium on Bio-logging Science, held on 14-18 March in Hobart, Australia, brought together scientists across multiple disciplines to discuss the latest innovations in technology, applications and analytical techniques in bio-logging science, building on research presented at three previous conferences. Here we present an update on the state of bio-logging research and provide some views on the future of this field of research. Papers were grouped into five theme areas: (i) Southern Ocean ecosystems; (ii) fishery and biodiversity management applications; (iii) from individuals to populations—inferences of population dynamics from individuals; (iv) conservation biology and (v) habitat modelling. Papers reflected wider uptake of newer technologies, with a greater proportion of studies utilising accelerometry and incorporating advances in statistical modelling of behaviour and habitats, especially via state space modelling methods. Environmental data collected by tags at increasing accuracies are now having wider application beyond the bio-logging community, providing important oceanographic data from regions difficult to sample using traditional methodologies. Partnerships between multiple organisations are also now enabling regional assessments of species movements, behaviour and physiology at population scales and will continue to be important for applying bio-logging technologies to species

  18. Fundamentals of electrokinetics

    NASA Astrophysics Data System (ADS)

    Kozak, M. W.

    The study of electrokinetics is a very mature field. Experimental studies date from the early 1800s, and acceptable theoretical analyses have existed since the early 1900s. The use of electrokinetics in practical field problems is more recent, but it is still quite mature. Most developments in the fundamental understanding of electrokinetics are in the colloid science literature. A significant and increasing divergence between the theoretical understanding of electrokinetics found in the colloid science literature and the theoretical analyses used in interpreting applied experimental studies in soil science and waste remediation has developed. The soil science literature has to date restricted itself to the use of very early theories, with their associated limitations. The purpose of this contribution is to review fundamental aspects of electrokinetic phenomena from a colloid science viewpoint. It is hoped that a bridge can be built between the two branches of the literature, from which both will benefit. Attention is paid to special topics such as the effects of overlapping double layers, applications in unsaturated soils, the influence of dispersivity, and the differences between electrokinetic theory and conductivity theory.

  19. Progress report on understanding AFIS seed coat nep levels in pre-opened slivers on the Advanced Fiber Information System (AFIS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Advanced Fiber Information System (AFIS) is utilized in this segment of the research project to study how seed coat neps are measured. A patent search was conducted, and studied to assist with the understanding of the AFIS measurement of this impurity in raw cotton. The older AFIS 2 is primari...

  20. Fundamentals of Atmospheric Radiation

    NASA Astrophysics Data System (ADS)

    Bohren, Craig F.; Clothiaux, Eugene E.

    2006-02-01

    This textbook fills a gap in the literature for teaching material suitable for students of atmospheric science and courses on atmospheric radiation. It covers the fundamentals of emission, absorption, and scattering of electromagnetic radiation from ultraviolet to infrared and beyond. Much of the book applies to planetary atmosphere. The authors are physicists and teach at the largest meteorology department of the US at Penn State. Craig T. Bohren has taught the atmospheric radiation course there for the past 20 years with no book. Eugene Clothiaux has taken over and added to the course notes. Problems given in the text come from students, colleagues, and correspondents. The design of the figures especially for this book is meant to ease comprehension. Discussions have a graded approach with a thorough treatment of subjects, such as single scattering by particles, at different levels of complexity. The discussion of the multiple scattering theory begins with piles of plates. This simple theory introduces concepts in more advanced theories, i.e. optical thickness, single-scattering albedo, asymmetry parameter. The more complicated theory, the two-stream theory, then takes the reader beyond the pile-of-plates theory. Ideal for advanced undergraduate and graduate students of atmospheric science.

  1. Fundamentals and Techniques of Nonimaging

    SciTech Connect

    O'Gallagher, J. J.; Winston, R.

    2003-07-10

    This is the final report describing a long term basic research program in nonimaging optics that has led to major advances in important areas, including solar energy, fiber optics, illumination techniques, light detectors, and a great many other applications. The term ''nonimaging optics'' refers to the optics of extended sources in systems for which image forming is not important, but effective and efficient collection, concentration, transport, and distribution of light energy is. Although some of the most widely known developments of the early concepts have been in the field of solar energy, a broad variety of other uses have emerged. Most important, under the auspices of this program in fundamental research in nonimaging optics established at the University of Chicago with support from the Office of Basic Energy Sciences at the Department of Energy, the field has become very dynamic, with new ideas and concepts continuing to develop, while applications of the early concepts continue to be pursued. While the subject began as part of classical geometrical optics, it has been extended subsequently to the wave optics domain. Particularly relevant to potential new research directions are recent developments in the formalism of statistical and wave optics, which may be important in understanding energy transport on the nanoscale. Nonimaging optics permits the design of optical systems that achieve the maximum possible concentration allowed by physical conservation laws. The earliest designs were constructed by optimizing the collection of the extreme rays from a source to the desired target: the so-called ''edge-ray'' principle. Later, new concentrator types were generated by placing reflectors along the flow lines of the ''vector flux'' emanating from lambertian emitters in various geometries. A few years ago, a new development occurred with the discovery that making the design edge-ray a functional of some other system parameter permits the construction of whole

  2. Fundamental Atomtronic Circuit Elements

    NASA Astrophysics Data System (ADS)

    Lee, Jeffrey; McIlvain, Brian; Lobb, Christopher; Hill, Wendell T., III

    2012-06-01

    Recent experiments with neutral superfluid gases have shown that it is possible to create atomtronic circuits analogous to existing superconducting circuits. The goals of these experiments are to create complex systems such as Josephson junctions. In addition, there are theoretical models for active atomtronic components analogous to diodes, transistors and oscillators. In order for any of these devices to function, an understanding of the more fundamental atomtronic elements is needed. Here we describe the first experimental realization of these more fundamental elements. We have created an atomtronic capacitor that is discharged through a resistance and inductance. We will discuss a theoretical description of the system that allows us to determine values for the capacitance, resistance and inductance. The resistance is shown to be analogous to the Sharvin resistance, and the inductance analogous to kinetic inductance in electronics. This atomtronic circuit is implemented with a thermal sample of laser cooled rubidium atoms. The atoms are confined using what we call free-space atom chips, a novel optical dipole trap produced using a generalized phase-contrast imaging technique. We will also discuss progress toward implementing this atomtronic system in a degenerate Bose gas.

  3. Fundamentals of gas measurement I

    SciTech Connect

    Dodds, D.E.

    1995-12-01

    To truly understand gas measurement, a person must understand gas measurement fundamentals. This includes the units of measurement, the behavior of the gas molecule, the property of gases, the gas laws, and the methods and means of measuring gas. Since the quality of gas is often the responsibility of the gas measurement technician, it is important that he or she have a knowledge of natural gas chemistry.

  4. Advancing Understanding of the Role of Belowground Processes in Terrestrial Carbon Sinks trhrough Ground-Penetrating Radar. Final Report

    SciTech Connect

    Day, Frank P.

    2015-02-06

    scanning events; however, it appears to lack sufficient accuracy at small scales. Knowledge of soil conditions and their effects on GPR wave propagation and reception are paramount for the collection of useful data. Strong familiarity with the software and equipment is both important and necessary for GPR use in estimating coarse root biomass. GPR must be utilized at low soil moisture levels in order to accurately represent existing coarse root structures. Our results from Disney Wilderness Preserve highlight the need for a strong understanding of the limitations of GPR, specifically knowledge of root structures (saw palmetto rhizomes) or environmental factors (low moisture content) that may hinder its application within a given system. The 3D modeling of course roots with GPR appears quite promising, as it has become more accurate and precise as the software has advanced and become more robust, but there is still a need for more precision before it will likely be able to model anything more than simple root systems comprised mostly of large diameter roots. Our results from Kennedy Space Center suggest that there are legacy effects from CO2 fertilization in the form of more root mass providing a greater capacity for aboveground plant regrowth following fire, even 7 years after treatment ended.

  5. Fundamental Thermal Fluid Physics of High Temperature Flows in Advanced Reactor Systems - Nuclear Energy Research Initiative Program Interoffice Work Order (IWO) MSF99-0254 Final Report for Period 1 August 1999 to 31 December 2002

    SciTech Connect

    McEligot, D.M.; Condie, K.G.; Foust, T.D.; McCreery, G.E.; Pink, R.J.; Stacey, D.E.; Shenoy, A.; Baccaglini, G.; Pletcher, R.H.; Wallace, J.M.; Vukoslavcevic, P.; Jackson, J.D.; Kunugi, T.; Satake, S.-i.

    2002-12-31

    The ultimate goal of the study is the improvement of predictive methods for safety analyses and design of advanced reactors for higher efficiency and enhanced safety and for deployable reactors for electrical power generation, process heat utilization and hydrogen generation. While key applications would be advanced gas-cooled reactors (AGCRs) using the closed Brayton cycle (CBC) for higher efficiency (such as the proposed Gas Turbine - Modular Helium Reactor (GT-MHR) of General Atomics [Neylan and Simon, 1996]), results of the proposed research should also be valuable in reactor systems with supercritical flow or superheated vapors, e.g., steam. Higher efficiency leads to lower cost/kwh and reduces life-cycle impacts of radioactive waste (by reducing waters/kwh). The outcome will also be useful for some space power and propulsion concepts and for some fusion reactor concepts as side benefits, but they are not the thrusts of the investigation. The objective of the project is to provide fundamental thermal fluid physics knowledge and measurements necessary for the development of the improved methods for the applications.

  6. Lighting Fundamentals. Monograph Number 13.

    ERIC Educational Resources Information Center

    Locatis, Craig N.; Gerlach, Vernon S.

    Using an accompanying, specified film that consists of 10-second pictures separated by blanks, the learner can, with the 203-step, self-correcting questions and answers provided in this program, come to understand the fundamentals of lighting in photography. The learner should, by the end of the program, be able to describe and identify the…

  7. Testing Our Fundamental Assumptions

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these

  8. Using an Advanced Computational Laboratory Experiment to Extend and Deepen Physical Chemistry Students' Understanding of Atomic Structure

    ERIC Educational Resources Information Center

    Hoffman, Gary G.

    2015-01-01

    A computational laboratory experiment is described, which involves the advanced study of an atomic system. The students use concepts and techniques typically covered in a physical chemistry course but extend those concepts and techniques to more complex situations. The students get a chance to explore the study of atomic states and perform…

  9. Lectures in Advanced Mathematics: Why Students Might Not Understand What the Mathematics Professor Is Trying to Convey

    ERIC Educational Resources Information Center

    Lew, Kristen; Fukawa-Connelly, Timothy Patrick; Mejía-Ramos , Juan Pablo; Weber, Keith

    2016-01-01

    We describe a case study in which we investigate the effectiveness of a lecture in advanced mathematics. We first videorecorded a lecture delivered by an experienced professor who had a reputation for being an outstanding instructor. Using video recall, we then interviewed the professor to determine the ideas that he intended to convey and how he…

  10. A decade of advancement in understanding of rangeland hydrology and erosion and the effects of conservation practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past decade the USDA-ARS Northwest Watershed Research Center (NWRC) has conducted extensive field research to quantify hydrologic and erosion effects of rangeland conservation practices and to develop and advance tools for rangeland assessment and management. Much of what was previously kn...

  11. Investigating the Effect of Different Verbal Formats of Advance Organizers on Third Graders' Understanding of Heat Transfer Concept

    ERIC Educational Resources Information Center

    Chuang, Hsueh-Hua; Liu, Han-Chin

    2014-01-01

    The emergence of computer and multimedia technology change the forms of instructional materials and instructional design plays an important role on student learning outcome in multimedia learning. Research has found that using advance organizers has the potential for achieving learning objectives. Thus, this study investigated how using different…

  12. Investigating the Effect of Different Verbal Formats of Advance Organizers on Third Graders' Understanding of Heat Transfer Concept

    ERIC Educational Resources Information Center

    Chuang, Hsueh-Hua; Liu, Han-Chin

    2014-01-01

    The emergence of computer and multimedia technology change the forms of instructional materials and instructional design plays an important role on student learning outcome in multimedia learning. Research has found that using advance organizers has the potential for achieving learning objectives. Thus, this study investigated how using different…

  13. Fundamentals and advances in magnetic hyperthermia

    NASA Astrophysics Data System (ADS)

    Périgo, E. A.; Hemery, G.; Sandre, O.; Ortega, D.; Garaio, E.; Plazaola, F.; Teran, F. J.

    2015-12-01

    Nowadays, magnetic hyperthermia constitutes a complementary approach to cancer treatment. The use of magnetic particles as heating mediators, proposed in the 1950s, provides a novel strategy for improving tumor treatment and, consequently, patient's quality of life. This review reports a broad overview about several aspects of magnetic hyperthermia addressing new perspectives and the progress on relevant features such as the ad hoc preparation of magnetic nanoparticles, physical modeling of magnetic heating, methods to determine the heat dissipation power of magnetic colloids including the development of experimental apparatus and the influence of biological matrices on the heating efficiency.

  14. Exchange Rates and Fundamentals.

    ERIC Educational Resources Information Center

    Engel, Charles; West, Kenneth D.

    2005-01-01

    We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…

  15. Advancing Fourth-Grade Students' Understanding of Arithmetic Properties with Instruction That Promotes Mathematical Argumentation

    ERIC Educational Resources Information Center

    Rumsey, Chepina Witkowski

    2012-01-01

    The goals for this study were to investigate how fourth-grade students developed an understanding of the arithmetic properties when instruction promoted mathematical argumentation and to identify the characteristics of students' arguments. Using the emergent perspective as an overarching theoretical perspective helped distinguish between two…

  16. Socioscientific Issues: A Path Towards Advanced Scientific Literacy and Improved Conceptual Understanding of Socially Controversial Scientific Theories

    NASA Astrophysics Data System (ADS)

    Pinzino, Dean William

    This thesis investigates the use of socioscientific issues (SSI) in the high school science classroom as an introduction to argumentation and socioscientific reasoning, with the goal of improving students' scientific literacy (SL). Current research is reviewed that supports the likelihood of students developing a greater conceptual understanding of scientific theories as well as a deeper understanding of the nature of science (NOS), through participation in informal and formal forms of argumentation in the context of SSI. Significant gains in such understanding may improve a student's ability to recognize the rigor, legitimacy, and veracity of scientific claims and better discern science from pseudoscience. Furthermore, students that participate in significant SSI instruction by negotiating a range of science-related social issues can make significant gains in content knowledge and develop the life-long skills of argumentation and evidence-based reasoning, goals not possible in traditional lecture-based science instruction. SSI-based instruction may therefore help students become responsible citizens. This synthesis also suggests that that the improvements in science literacy and NOS understanding that develop from sustained engagement in SSI-based instruction will better prepare students to examine and scrutinize socially controversial scientific theories (i.e., evolution, global warming, and the Big Bang).

  17. Fast Tracking Data to Informed Decisions: An Advanced Information System to Improve Environmental Understanding and Management (Invited)

    NASA Astrophysics Data System (ADS)

    Minsker, B. S.; Myers, J.; Liu, Y.; Bajcsy, P.

    2010-12-01

    Emerging sensing and information technology are rapidly creating a new paradigm for environmental research and management, in which data from multiple sensors and information sources can guide real-time adaptive observation and decision making. This talk will provide an overview of emerging cyberinfrastructure and three case studies that illustrate their potential: combined sewer overflows in Chicago, hypoxia in Corpus Christi Bay, Texas, and sustainable agriculture in Illinois. An advanced information system for real-time decision making and visual geospatial analytics will be presented as an example of cyberinfrastructure that enables easier implementation of numerous real-time applications.

  18. Intergovernmental Conference on Education and International Understanding, Co-operation and Peace and Education Relating to Human Rights and Fundamental Freedoms, with a View to Developing a Climate of Opinion Favourable to the Strengthening of Security and Disarmament (Paris, France, April 12-20, 1983). Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    The purpose of this conference was to review the activities undertaken by members to implement the recommendations established by the 1980 General Conference concerning education aimed at international understanding and cooperation, peace, human rights, and fundamental freedoms. Pepresentatives of 122 member states of UNESCO attended this…

  19. Fundamentals of plasma simulation

    SciTech Connect

    Forslund, D.W.

    1985-01-01

    With the increasing size and speed of modern computers, the incredibly complex nonlinear properties of plasmas in the laboratory and in space are being successfully explored in increasing depth. Of particular importance have been numerical simulation techniques involving finite size particles on a discrete mesh. After discussing the importance of this means of understanding a variety of nonlinear plasma phenomena, we describe the basic elements of particle-in-cell simulation and their limitations and advantages. The differencing techniques, stability and accuracy issues, data management and optimization issues are discussed by means of a simple example of a particle-in-cell code. Recent advances in simulation methods allowing large space and time scales to be treated with minimal sacrifice in physics are reviewed. Various examples of nonlinear processes successfully studied by plasma simulation will be given.

  20. Testing Our Fundamental Assumptions

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these

  1. Advances in Understanding the Role of Aerosols on Ice Clouds from the Fifth International Ice Nucleation (FIN) Workshops

    NASA Astrophysics Data System (ADS)

    Cziczo, D. J.; Moehler, O.; DeMott, P. J.

    2015-12-01

    The relationship of ambient aerosol particles to the formation of ice-containing clouds is one of the largest uncertainties in understanding climate. This is due to several poorly understood processes including the microphysics of how particles nucleate ice, the number of effective heterogeneous ice nuclei and their atmospheric distribution, the role of anthropogenic activities in producing or changing the behavior of ice forming particles and the interplay between effective heterogeneous ice nuclei and homogeneous ice formation. Our team recently completed a three-part international workshop to improve our understanding of atmospheric ice formation. Termed the Fifth International Ice Nucleation (FIN) Workshops, our motivation was the limited number of measurements and a lack of understanding of how to compare data acquired by different groups. The first activity, termed FIN1, addressed the characterization of ice nucleating particle size, number and chemical composition. FIN2 addressed the determination of ice nucleating particle number density. Groups modeling ice nucleation joined FIN2 to provide insight on measurements critically needed to model atmospheric ice nucleation and to understand the performance of ice chambers. FIN1 and FIN2 took place at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) chamber at the Karlsruhe Institute of Technology. A particular emphasis of FIN1 and FIN2 was the use of 'blind' intercomparisons using a highly characterized, but unknown to the instrument operators, aerosol sample. The third activity, FIN3, took place at the Desert Research Institute's Storm Peak Laboratory (SPL). A high elevation site not subject to local emissions, SPL allowed for a comparison of ice chambers and subsequent analysis of the ice residuals under the challenging conditions of low particle loading, temperature and pressure found in the atmosphere. The presentation focuses on the improvement in understanding how mass spectra from different

  2. Regenerative medicine and hair loss: how hair follicle culture has advanced our understanding of treatment options for androgenetic alopecia.

    PubMed

    Higgins, Claire A; Christiano, Angela M

    2014-01-01

    Many of the current drug therapies for androgenetic alopecia were discovered serendipitously, with hair growth observed as an off-target effect when drugs were used to treat a different disorder. Subsequently, several studies using cultured cells have enabled identification of hair growth modulators with similar properties to the currently available drugs, which may also provide clinical benefit. In situations where the current therapeutics do not work, follicular unit transplantation is an alternative surgical option. More recently, the concept of follicular cell implantation, or hair follicle neogenesis, has been attempted, exploiting the inherent properties of cultured hair follicle cells to induce de novo hair growth in balding scalp. In this review, we discuss both the advances in cell culture techniques that have led to a wider range of potential therapeutics to promote hair growth, in addition to detailing current knowledge on follicular cell implantation, and the challenges in making this approach a reality. PMID:24351010

  3. DOE Fundamentals Handbook: Classical Physics

    SciTech Connect

    Not Available

    1992-06-01

    The Classical Physics Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of physical forces and their properties. The handbook includes information on the units used to measure physical properties; vectors, and how they are used to show the net effect of various forces; Newton's Laws of motion, and how to use these laws in force and motion applications; and the concepts of energy, work, and power, and how to measure and calculate the energy involved in various applications. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility systems and equipment.

  4. MO-E-18C-04: Advanced Computer Simulation and Visualization Tools for Enhanced Understanding of Core Medical Physics Concepts

    SciTech Connect

    Naqvi, S

    2014-06-15

    Purpose: Most medical physics programs emphasize proficiency in routine clinical calculations and QA. The formulaic aspect of these calculations and prescriptive nature of measurement protocols obviate the need to frequently apply basic physical principles, which, therefore, gradually decay away from memory. E.g. few students appreciate the role of electron transport in photon dose, making it difficult to understand key concepts such as dose buildup, electronic disequilibrium effects and Bragg-Gray theory. These conceptual deficiencies manifest when the physicist encounters a new system, requiring knowledge beyond routine activities. Methods: Two interactive computer simulation tools are developed to facilitate deeper learning of physical principles. One is a Monte Carlo code written with a strong educational aspect. The code can “label” regions and interactions to highlight specific aspects of the physics, e.g., certain regions can be designated as “starters” or “crossers,” and any interaction type can be turned on and off. Full 3D tracks with specific portions highlighted further enhance the visualization of radiation transport problems. The second code calculates and displays trajectories of a collection electrons under arbitrary space/time dependent Lorentz force using relativistic kinematics. Results: Using the Monte Carlo code, the student can interactively study photon and electron transport through visualization of dose components, particle tracks, and interaction types. The code can, for instance, be used to study kerma-dose relationship, explore electronic disequilibrium near interfaces, or visualize kernels by using interaction forcing. The electromagnetic simulator enables the student to explore accelerating mechanisms and particle optics in devices such as cyclotrons and linacs. Conclusion: The proposed tools are designed to enhance understanding of abstract concepts by highlighting various aspects of the physics. The simulations serve as

  5. Advances in understanding the genesis and evolution solar energetic particle events over the last two solar cycles

    NASA Astrophysics Data System (ADS)

    Vainio, Rami

    2016-04-01

    I will review the observational and modeling efforts related to solar energetic particle (SEP) events over the 23rd and 24th solar cycles. I will concentrate on large SEP events related to coronal mass ejections (CMEs), but discuss observations related to the possible role of flares in the acceleration of particles in those events, as well. The possible roles of various acceleration and transport processes in understanding the characteristics of the events will be discussed. This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA).

  6. Understanding the Redox Obstacles in High Sulfur-Loading Li-S Batteries and Design of an Advanced Gel Cathode.

    PubMed

    Zu, Chenxi; Li, Longjun; Guo, Jianhe; Wang, Shaofei; Fan, Donglei; Manthiram, Arumugam

    2016-04-01

    Lithium-sulfur batteries with a high energy density are being considered a promising candidate for next-generation energy storage. However, realization of Li-S batteries is plagued by poor sulfur utilization due to the shuttle of intermediate lithiation products between electrodes and its dynamic redistribution. To optimize the sulfur utilization, an understanding of its redox behavior is essential. Herein, we report a gel cathode consisting of a polysulfide-impregnated O- and N-doped porous carbon and an independent, continuous, and highly conducting 3-dimensional graphite film as the charge-transfer network. This design decouples the function of electron conduction and polysulfide absorption, which is beneficial for understanding the sulfur redox behavior and identifying the dominant factors leading to cell failure when the cells have high sulfur content and insufficient electrolyte. This design also opens up new prospects of tuning the properties of Li-S batteries via separately designing the material functions of electron conduction and polysulfide absorption. PMID:27014923

  7. Advances in clinical and molecular understanding of the FMR1 premutation and fragile X-associated tremor/ataxia syndrome

    PubMed Central

    Hagerman, Randi; Hagerman, Paul

    2014-01-01

    Summary Fragile X syndrome, the leading heritable form of cognitive impairment, is caused by epigenetic silencing of the fragile X (FMR1) gene consequent to large expansions (>200 repeats) of a non-coding CGG-repeat element. Smaller, “premutation” expansions (55–200 repeats) can give rise to a family of neurodevelopmental (ADHD, autism spectrum disorder, seizure disorder) and neurodegenerative (FXTAS) clinical phenotypes through an entirely distinct molecular mechanism involving increased FMR1 mRNA production and toxicity. Basic cellular, animal, and human studies have helped to elucidate the underlying RNA toxicity mechanism, while clinical research is providing a more nuanced picture of the spectrum of clinical involvement. Whereas advances on both mechanistic and clinical fronts are driving new approaches to targeted treatment, two important issues/needs are emerging: to define the extent to which the mechanisms contributing to FXTAS also contribute to other neurodegenerative and medical disorders, and to redefine FXTAS in light of its differing presentations and associated features. PMID:23867198

  8. Insight into Pathologic Abnormalities in Congenital Semilunar Valve Disease Based on Advances in Understanding Normal Valve Microstructure and Extracellular Matrix

    PubMed Central

    Stephens, Elizabeth H.; Kearney, Debra L.; Grande-Allen, K. Jane

    2011-01-01

    Congenitally diseased valves are relatively frequent causes of significant morbidity and mortality. Pathology descriptions of such valves have primarily focused on gross structural features including the number of leaflets or commissures (bicuspid/bicommissural valve) and alterations in the contour, thickness and consistency of the leaflets (dysplastic valve). Functional correlates of these pathologic alterations are valvar stenosis, insufficiency or both. Further characterization of the microstructural abnormalities seen in these malformed valves may not only provide insight into the correlation of distinct pathologies with their respective pathogenesis and clinical sequelae, but also may prove pivotal in uncovering new avenues for therapeutic interventions and prevention regimens. This review summarizes microstructural findings in congenital semilunar valve disease (CSVD) and discusses their relevance in light of recent advances in knowledge of normal valve microstructure, biology, and function. Specifically, the biological and mechanical roles of various matrix components and their interactions are discussed in the context of CSVD. Indeed, recent research in normal valves adds significant insight into CSVD, and raises many hypotheses that will need to be addressed by future studies. PMID:21349746

  9. Investigation of fundamental limits to beam brightness available from photoinjectors

    SciTech Connect

    Bazarov, Ivan

    2015-07-09

    The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.

  10. Recent Advances in Understanding the Microbiology of the Female Reproductive Tract and the Causes of Premature Birth

    PubMed Central

    Zhou, Xia; Brotman, Rebecca M.; Gajer, Pawel; Abdo, Zaid; Schüette, Ursel; Ma, Sam; Ravel, Jacques; Forney, Larry J.

    2010-01-01

    Data derived from molecular microbiological investigations of the human vagina have led to the discovery of resident bacterial communities that exhibit marked differences in terms of species composition. All undergo dynamic changes that are likely due to intrinsic host and behavioral factors. Similar types of bacteria have been found in both amniotic fluid and the vagina, suggesting a potential route of colonization. Given that not all of the species involved in intrauterine infections are readily cultivated, it is important that culture-independent methods of analysis must be used to understand the etiology of these infections. Further research is needed to establish whether an ascending pathway from the vagina to the amniotic cavity enables the development of intrauterine infections. PMID:21197076

  11. Training preschoolers on first-order false belief understanding: transfer on advanced ToM skills and metamemory.

    PubMed

    Lecce, Serena; Bianco, Federica; Demicheli, Patrizia; Cavallini, Elena

    2014-01-01

    This study investigated the relation between theory of mind (ToM) and metamemory knowledge using a training methodology. Sixty-two 4- to 5-year-old children were recruited and randomly assigned to one of two training conditions: A first-order false belief (ToM) and a control condition. Intervention and control groups were equivalent at pretest for age, parents' education, verbal ability, inhibition, and ToM. Results showed that after the intervention children in the ToM group improved in their first-order false belief understanding significantly more than children in the control condition. Crucially, the positive effect of the ToM intervention was stable over 2 months and generalized to more complex ToM tasks and metamemory. PMID:25040788

  12. NASA's Advancements in Space-Based Spectrometry Lead to Improvements in Weather Prediction and Understanding of Climate Processes

    NASA Technical Reports Server (NTRS)

    Susskind, Joel

    2010-01-01

    AIRS is a precision state of the art High Spectral Resolution Multi-detector IR grating array spectrometer that was launched into a polar orbit on EOS Aqua in 2002. AIRS measures most of the infra-red spectrum with very low noise from 650/cm to 2660/cm with a resolving power of 2400 at a spatial resolution of 13 km. The objectives of AIRS were to perform accurate determination of atmospheric temperature and moisture profiles in up to 90% partial cloud cover conditions for the purpose of improving numerical weather prediction and understanding climate processes. AIRS data has also been used to determine accurate trace gas profiles. A brief overview of the retrieval methodology used to analyze AIRS observations under partial cloud cover will be presented and sample results will be shown from the weather and climate perspectives.

  13. Advances in the Understanding of ELM Suppression by Resonant Magnetic Perturbations (RMPs) in DIII-D and Implications for ITER

    SciTech Connect

    Nazikian, R.

    2014-09-01

    Experiments on DIII-D have expanding the operating window for RMP ELM suppression to higher q95 with dominant electron heating and fully non-inductive current drive relevant to advanced modes of ITER operation. Robust ELM suppression has also been obtained with a reduced coil set, mitigating the risk of coil failure in maintaining ELM suppression in ITER. These results significantly expand the operating space and reduce risk for obtaining RMP ELM suppression in ITER. Efforts have also been made to search for 3D cause of ELM suppression. No internal non-axisymmetric structure is detected at the top of the pedestal, indicating that the dominant effect of the RMP is to produce an n=0 transport modification of the profiles. Linear two fluid MHD simulations using M3D-C1 indicate resonant field penetration and significant magnetic stochasticity at the top of the pedestal, consistent with the absence of detectable 3D structure in that region. A profile database was developed to compare the scaling of the pedestal and global confinement with the applied 3D field strength in ELM suppressed and ELM mitigated plasmas. The EPED pedestal model accurately predicts the measured pedestal pressure at the threshold of ELM suppression, increasing confidence in theoretical projections to ITER pedestal conditions. Both the H-factor (H(sub)98y2) and thermal energy confinement time do not degrade substantially with applied RMP fields near the threshold of ELM suppression, enhancing confidence in the compatibility of ITER high performance operation with RMP ELM suppression.

  14. Fundamental Physical Constants

    National Institute of Standards and Technology Data Gateway

    SRD 121 CODATA Fundamental Physical Constants (Web, free access)   This site, developed in the Physics Laboratory at NIST, addresses three topics: fundamental physical constants, the International System of Units (SI), which is the modern metric system, and expressing the uncertainty of measurement results.

  15. Electric Potential Surrounding Two Conducting Spheres: An Exercise for Advancing Student Understanding of the Method of Relaxation

    NASA Astrophysics Data System (ADS)

    Gallagher, Hugh; Chartrand, Bridget; Beach, John

    2016-03-01

    In undergraduate computational physics courses, the method of relaxation provides a well-established technique for obtaining solutions to Laplace's Equation. The technique's value stems from its accessibility and clear dependence on the properties of solutions to Laplace's Equation. We have created an exercise that allows students to develop an experiential understanding of the method of images and its connection to the properties of solutions to Laplace's Equation. The problem of two conducting spheres separated by a relatively small distance and maintained at fixed but distinct electric potentials is considered. Using the method of relaxation, students solve the problem in two-dimensions, three-dimensions with a Dirichlet condition on the outer boundary and three-dimensions using a Neumann condition on the outer boundary. At each step, the results are compared to a solution obtained using the method of images for a spherical conductor in an iterative fashion. Through this comparison, students gain insight into the significance of their choices for the solving the problem using the method of relaxation. We will discuss application of the relaxation method to this problem, validation by the method of images, and potential use in an undergraduate computational physics course.

  16. Recent advances in the biotechnological production of microbial poly(ɛ-L-lysine) and understanding of its biosynthetic mechanism.

    PubMed

    Xu, Zhaoxian; Xu, Zheng; Feng, Xiaohai; Xu, Delei; Liang, Jinfeng; Xu, Hong

    2016-08-01

    Poly(ɛ-L-lysine) (ɛ-PL) is an unusual biopolymer composed of L-lysine connected between α-carboxyl and ɛ-amino groups. It has been used as a preservative in food and cosmetics industries, drug carrier in medicines, and gene carrier in gene therapy. Modern biotechnology has significantly improved the synthetic efficiency of this novel homopoly(amino acid) on an industrial scale and has expanded its industrial applications. In the latest years, studies have focused on the biotechnological production and understanding the biosynthetic mechanism of microbial ɛ-PL. Herein, this review focuses on the current trends and future perspectives of microbial ɛ-PL. Information on the screening of ɛ-PL-producing strains, fermentative production of ɛ-PL, breeding of high-ɛ-PL-producing strains, genomic data of ɛ-PL-producing strains, biosynthetic mechanism of microbial ɛ-PL, and the control of molecular weight of microbial ɛ-PL is included. This review will contribute to the development of this novel homopoly(amino acid) and serve as a basis of studies on other biopolymers. PMID:27333910

  17. Co-existence of tic disorders and attention-deficit/hyperactivity disorder-recent advances in understanding and treatment.

    PubMed

    Rothenberger, Aribert; Roessner, Veit; Banaschewski, Tobias; Leckman, James F

    2007-06-01

    In daily clinical practice of child psychiatry tic disorders (TD) and attention-deficit/hyperactivity disorder (ADHD) as well as their co-existence are common and need careful evidence-based approaches in differential diagnostics and treatment choice. Hence, their relationship at different levels (e.g., psychopathology, neuropsychology, neurobiology, treatment) needs to be elucidated in more detail. The articles of this supplement deal with this subject. It is unclear if TD + ADHD represents an own clinical entity and which component (TD vs. ADHD) is most important in case of co-existence with respect to accompanying problems like emotional or cognitive disturbances. This editorial gives a short overview of the essential research topics concerning TD + ADHD and shows where (in this ECAP supplement and other literature) empirically based answers can be found. Probably, the identification of separate or common "endophenotypes" for TD-only, ADHD-only and for TD + ADHD would help to sort out the complexities and this supplement may nurture such a perspective of future research for a better understanding and treatment of youths with TD + ADHD and their families. PMID:17665277

  18. NASA's Advancements in Space-Based Spectrometry Lead to Improvements in Weather Prediction and Understanding of Climate Processes

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Iredell, Lena

    2010-01-01

    AIRS (Atmospheric Infra-Red Sounder), was launched, in conjunction with AMSU-A (Advanced Microwave Sounding Unit-A) on the NASA polar orbiting research satellite EOS (Earth Observing System) Aqua satellite in May 2002 as a next generation atmospheric sounding system. Atmospheric sounders provide information primarily about the vertical distribution of atmospheric temperature and water vapor distribution. This is achieved by measuring outgoing radiation in discrete channels (spectral intervals) which are sensitive primarily to variations of these geophysical parameters. The primary objectives of AIRS/AMSU were to utilize such information in order to improve the skill of numerical weather prediction as well as to measure climate variability and trends. AIRS is a multi-detector array grating spectrometer with 2378 channels covering the spectral range 650/cm (15 microns) to 2660/cm (3.6 microns) with a resolving power (i/a i) of roughly 1200 where a i is the spectral channel bandpass. Atmospheric temperature profile can be determined from channel observations taken within the 15 micron (the long-wave CO2 absorption band) and within the 4.2 micron (the short-wave CO2 absorption band). Radiances in these (and all other) spectral intervals in the infrared are also sensitive to the presence of clouds in the instrument?s field of view (FOV), which are present about 95% of the time. AIRS was designed so as to allow for the ability to produce accurate Quality Controlled atmospheric soundings under most cloud conditions. This was achieved by having 1) extremely low channel noise values in the shortwave portion of the spectrum and 2) a very flat spatial response function within a channel?s FOV. IASI, the high spectral resolution IR interferometer flying on the European METOP satellite, does not contain either of these important characteristics. The AIRS instrument was also designed to be extremely stabile with regard to its spectral radiometric characteristics, which is

  19. Advances in systems biology are enhancing our understanding of disease and moving us closer to novel disease treatments.

    PubMed

    Schadt, Eric E; Zhang, Bin; Zhu, Jun

    2009-06-01

    With tens of billions of dollars spent each year on the development of drugs to treat human diseases, and with fewer and fewer applications for investigational new drugs filed each year despite this massive spending, questions now abound on what changes to the drug discovery paradigm can be made to achieve greater success. The high rate of failure of drug candidates in clinical development, where the great majority of these drugs fail due to lack of efficacy, speak directly to the need for more innovative approaches to study the mechanisms of disease and drug discovery. Here we review systems biology approaches that have been devised over the last several years to understand the biology of disease at a more holistic level. By integrating a diversity of data like DNA variation, gene expression, protein-protein interaction, DNA-protein binding, and other types of molecular phenotype data, more comprehensive networks of genes both within and between tissues can be constructed to paint a more complete picture of the molecular processes underlying physiological states associated with disease. These more integrative, systems-level methods lead to networks that are demonstrably predictive, which in turn provides a deeper context within which single genes operate such as those identified from genome-wide association studies or those targeted for therapeutic intervention. The more comprehensive views of disease that result from these methods have the potential to dramatically enhance the way in which novel drug targets are identified and developed, ultimately increasing the probability of success for taking new drugs through clinical development. We highlight a number of the integrative approaches via examples that have resulted not only in the identification of novel genes for diabetes and cardiovascular disease, but in more comprehensive networks as well that describe the context in which the disease genes operate. PMID:19363597

  20. Regional Arctic System Model (RASM): A Tool to Advance Understanding and Prediction of Arctic Climate Change at Process Scales

    NASA Astrophysics Data System (ADS)

    Maslowski, W.; Roberts, A.; Osinski, R.; Brunke, M.; Cassano, J. J.; Clement Kinney, J. L.; Craig, A.; Duvivier, A.; Fisel, B. J.; Gutowski, W. J., Jr.; Hamman, J.; Hughes, M.; Nijssen, B.; Zeng, X.

    2014-12-01

    The Arctic is undergoing rapid climatic changes, which are some of the most coordinated changes currently occurring anywhere on Earth. They are exemplified by the retreat of the perennial sea ice cover, which integrates forcing by, exchanges with and feedbacks between atmosphere, ocean and land. While historical reconstructions from Global Climate and Global Earth System Models (GC/ESMs) are in broad agreement with these changes, the rate of change in the GC/ESMs remains outpaced by observations. Reasons for that stem from a combination of coarse model resolution, inadequate parameterizations, unrepresented processes and a limited knowledge of physical and other real world interactions. We demonstrate the capability of the Regional Arctic System Model (RASM) in addressing some of the GC/ESM limitations in simulating observed seasonal to decadal variability and trends in the sea ice cover and climate. RASM is a high resolution, fully coupled, pan-Arctic climate model that uses the Community Earth System Model (CESM) framework. It uses the Los Alamos Sea Ice Model (CICE) and Parallel Ocean Program (POP) configured at an eddy-permitting resolution of 1/12° as well as the Weather Research and Forecasting (WRF) and Variable Infiltration Capacity (VIC) models at 50 km resolution. All RASM components are coupled via the CESM flux coupler (CPL7) at 20-minute intervals. RASM is an example of limited-area, process-resolving, fully coupled earth system model, which due to the additional constraints from lateral boundary conditions and nudging within a regional model domain facilitates detailed comparisons with observational statistics that are not possible with GC/ESMs. In this talk, we will emphasize the utility of RASM to understand sensitivity to variable parameter space, importance of critical processes, coupled feedbacks and ultimately to reduce uncertainty in arctic climate change projections.

  1. The Texas Water Observatory: Utilizing Advanced Observing System Design for Understanding Water Resources Sustainability Across Climatic and Geologic Gradients of Texas

    NASA Astrophysics Data System (ADS)

    Mohanty, B.; Moore, G. W.; Miller, G. R.; Quiring, S. M.; Everett, M. E.; Morgan, C.

    2015-12-01

    The Texas Water Observatory (TWO) is a new distributed network of field observatories for better understanding of the hydrologic flow in the critical zone (encompassing groundwater, soil water, surface water, and atmospheric water) at various space and time scales. Core sites in the network will begin in Brazos River corridor and expand from there westward. Using many advanced observational platforms and real-time / near-real time sensors, this observatory will monitor high frequency data of water stores and fluxes, critical for understanding and modeling the in the state of Texas and Southern USA. Once implemented, TWO will be positioned to support high-impact water science that is highly relevant to societal needs and serve as a regional resource for better understanding and/or managing agriculture, water resources, ecosystems, biodiversity, disasters, health, energy, and weather/climate. TWO infrastructure will span land uses (cultivation agriculture, range/pasture, forest), landforms (low-relief erosional uplands to depositional lowlands), and across climatic and geologic gradients of Texas to investigate the sensitivity and resilience of fertile soils and the ecosystems they support. Besides developing a network of field water observatory infrastructure/capacity for accounting water flow and storage, TWO will facilitate developing a new generation interdisciplinary water professionals (from various TAMU Colleges) with better understanding and skills for attending to future water challenges of the region. This holistic growth will have great impact on TAMU research enterprise related to water resources, leading to higher federal and state level competitiveness for funding and establishing a center of excellence in the region

  2. Fundamentals of Space Medicine

    NASA Astrophysics Data System (ADS)

    Clément, Gilles

    2005-03-01

    A total of more than 240 human space flights have been completed to date, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This readable text presents the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardio-vascular, bone, and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated, and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination of both the

  3. Fundamentals of Space Medicine

    NASA Astrophysics Data System (ADS)

    Clément, G.

    2003-10-01

    As of today, a total of more than 240 human space flights have been completed, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This book presents in a readable text the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardiovascular, bone and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination

  4. European Regional Seminar on Implementation of the UNESCO Recommendation Concerning Education for International Understanding, Co-operation and Peace and Education Relating to Human Rights and Fundamental Freedoms (Sofia, Bulgaria, 15-20 October 1979). Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    This document is the final report of the Unesco seminar on international understanding. The major purposes of the seminar were twofold: (1) to evaluate implementation of human rights and peace-related recommendations within Unesco member nations since 1974 and (2) to suggest how to develop and implement more effective human rights/international…

  5. A study of fundamental limitations of small antennas: MIMO approach

    NASA Astrophysics Data System (ADS)

    Mattigiri, S.; Warty, C.

    In this area of high performance systems and sophistication, the antenna size is shrinking drastically. This paper reviews the fundamental limitations in electrically instigated small antennas and their implications on multiple input multiple output (MIMO) systems. An optimum performance of the antenna can be obtained by considering three main factors. (1) maximum gain for given frequency (2) minimum Q factor (3) maximum ratio of G/Q. It is essential to understand the basic concepts of these small antennas to counter the limitations for next generational systems. In this paper works of three prominent scientists like Wheeler, Hansen and Chu have been studied to understand these limitations. This study can be further expanded to accumulate various space time diverse MIMO systems specified in long Term Evolution-Advanced (LTE-A) standards. The impact of limitations of small antennas can be very significant on the performance of the given node.

  6. A Biochemical Approach to Understand the Pathogenesis of Advanced Pulmonary Arterial Hypertension: Metabolomic Profiles of Arginine, Sphingosine-1-Phosphate, and Heme of Human Lung.

    PubMed

    Zhao, Yidan D; Chu, Lei; Lin, Kathleen; Granton, Elise; Yin, Li; Peng, Jenny; Hsin, Michael; Wu, Licun; Yu, Amy; Waddell, Thomas; Keshavjee, Shaf; Granton, John; de Perrot, Marc

    2015-01-01

    Pulmonary arterial hypertension (PAH) is a vascular disease characterized by persistent precapillary pulmonary hypertension (PH), leading to progressive right heart failure and premature death. The pathological mechanisms underlying this condition remain elusive. Analysis of global metabolomics from lung tissue of patients with PAH (n = 8) and control lung tissue (n = 8) leads to a better understanding of disease progression. Using a combination of high-throughput liquid-and-gas-chromatography-based mass spectrometry, we showed unbiased metabolomic profiles of disrupted arginine pathways with increased Nitric oxide (NO) and decreased arginine. Our results also showed specific metabolic pathways and genetic profiles with increased Sphingosine-1-phosphate (S1P) metabolites as well as increased Heme metabolites with altered oxidative pathways in the advanced stage of the human PAH lung. The results suggest that PAH has specific metabolic pathways contributing to the vascular remodeling in severe pulmonary hypertension. Profiling metabolomic alterations of the PAH lung has provided a new understanding of the pathogenic mechanisms of PAH, which benefits therapeutic targeting to specific metabolic pathways involved in the progression of PAH. PMID:26317340

  7. Recent Advances and Understanding of Using Probiotic-Based Interventions to Restore Homeostasis of the Microbiome for the Prevention/Therapy of Bacterial Diseases.

    PubMed

    Suchodolski, Jan S; Jergens, Albert E

    2016-04-01

    The importance of the microbiome in health and disease has galvanized interest in using manipulations of the gastrointestinal ecosystem to prevent and/or combat gut bacterial infections and to restore mucosal homeostasis in patients with generalized microbial imbalances (i.e., dysbiosis), including the human inflammatory bowel diseases, Crohn's disease, and ulcerative colitis. Probiotics, prebiotics, or their combination use (i.e., synbiotics) are one mechanism for modifying the microbiota and exerting direct and indirect effects on the host immune responses and metabolomics profiles. These beneficial effects are transferred through various pathways, including the production of antimicrobial peptides, promoting the growth of beneficial microbes and enhancing immunomodulatory functions via various metabolites. While probiotic therapy has been used empirically for decades with mixed success, the recent advances in molecular and mass spectrophotometric techniques for the characterization of the complexity and diversity of the intestinal microbiome has aided in better understanding of host-microbe interactions. It is important to better understand the functional properties of the microbiome, because it is now clear that the microbiota secretes many metabolites that have a direct impact on host immune responses. This information will improve selection of the most appropriate probiotic strains that selectively target intestinal disease processes. PMID:27227298

  8. A Biochemical Approach to Understand the Pathogenesis of Advanced Pulmonary Arterial Hypertension: Metabolomic Profiles of Arginine, Sphingosine-1-Phosphate, and Heme of Human Lung

    PubMed Central

    Zhao, Yidan D.; Chu, Lei; Lin, Kathleen; Granton, Elise; Yin, Li; Peng, Jenny; Hsin, Michael; Wu, Licun; Yu, Amy; Waddell, Thomas; Keshavjee, Shaf; Granton, John; de Perrot, Marc

    2015-01-01

    Pulmonary arterial hypertension (PAH) is a vascular disease characterized by persistent precapillary pulmonary hypertension (PH), leading to progressive right heart failure and premature death. The pathological mechanisms underlying this condition remain elusive. Analysis of global metabolomics from lung tissue of patients with PAH (n = 8) and control lung tissue (n = 8) leads to a better understanding of disease progression. Using a combination of high-throughput liquid-and-gas-chromatography-based mass spectrometry, we showed unbiased metabolomic profiles of disrupted arginine pathways with increased Nitric oxide (NO) and decreased arginine. Our results also showed specific metabolic pathways and genetic profiles with increased Sphingosine-1-phosphate (S1P) metabolites as well as increased Heme metabolites with altered oxidative pathways in the advanced stage of the human PAH lung. The results suggest that PAH has specific metabolic pathways contributing to the vascular remodeling in severe pulmonary hypertension. Profiling metabolomic alterations of the PAH lung has provided a new understanding of the pathogenic mechanisms of PAH, which benefits therapeutic targeting to specific metabolic pathways involved in the progression of PAH. PMID:26317340

  9. Advances in understanding colonic function.

    PubMed

    Milla, Peter J

    2009-04-01

    The colon is an organ of conservation that salvages water, electrolytes, and energy. The organization of colonic function is determined by the roles played by the luminal flora, the function of the different mucosal epithelial cell types, immunocompetent cells, and the neuromusculature. These different components of the colon interact with one another and with the colonic flora, and different areas of the colon serve different functions. In the normal adult during the course of a day the colon absorbs approximately 1.5 L of fluid, but under the influence of aldosterone increases up to 5 to 6 L. Diarrhoea occurs when secretion exceeds absorptive processes by either small intestinal secretion overwhelming colonic salvage or salvage being impaired by reduced colonic absorption or increased colonic secretion. PMID:19300122

  10. Advances in Understanding Hair Growth

    PubMed Central

    Bernard, Bruno A.

    2016-01-01

    In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a “Yin Yang” type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control. PMID:26918186

  11. Advances in Understanding Hair Growth.

    PubMed

    Bernard, Bruno A

    2016-01-01

    In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a "Yin Yang" type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control. PMID:26918186

  12. Monte Carlo fundamentals

    SciTech Connect

    Brown, F.B.; Sutton, T.M.

    1996-02-01

    This report is composed of the lecture notes from the first half of a 32-hour graduate-level course on Monte Carlo methods offered at KAPL. These notes, prepared by two of the principle developers of KAPL`s RACER Monte Carlo code, cover the fundamental theory, concepts, and practices for Monte Carlo analysis. In particular, a thorough grounding in the basic fundamentals of Monte Carlo methods is presented, including random number generation, random sampling, the Monte Carlo approach to solving transport problems, computational geometry, collision physics, tallies, and eigenvalue calculations. Furthermore, modern computational algorithms for vector and parallel approaches to Monte Carlo calculations are covered in detail, including fundamental parallel and vector concepts, the event-based algorithm, master/slave schemes, parallel scaling laws, and portability issues.

  13. Fundamentals of fluid lubrication

    NASA Technical Reports Server (NTRS)

    Hamrock, Bernard J.

    1991-01-01

    The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.

  14. Fundamentals of fluid sealing

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamentals of fluid sealing, including seal operating regimes, are discussed and the general fluid-flow equations for fluid sealing are developed. Seal performance parameters such as leakage and power loss are presented. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. The concept of pressure balancing is presented, as are differences between liquid and gas sealing. Mechanisms of seal surface separation, fundamental friction and wear concepts applicable to seals, seal materials, and pressure-velocity (PV) criteria are discussed.

  15. Fundamental bioprocessing research for coal applications

    SciTech Connect

    Kaufman, E.N.; Scott, T.C.

    1995-06-01

    The purpose of this program is to gain a fundamental understanding and sound scientific and technical basis for evaluating the potential roles of innovative bioprocessing concepts for the utilization and conversion of coal. The aim is to explore the numerous ways in which advanced biological processes and techniques can open new opportunities for coal utilization or can replace more conventional techniques by using milder conditions with less energy consumption or loss. There are several roles where biotechnology is likely to be important in coal utilization and conversion. These include potential bioprocessing systems such as conversion of coal to liquids or gases; biocatalytic beneficiation of coal-derived liquids and conversion to useful chemical feedstocks; biocatalytic removal of SO{sub x} and NO{sub x} from coal combustion off-gas; environmental control technology for the removal or destruction of hazardous materials in process effluents and/or solid residues; and the removal and utilization of CO{sub 2} from combustion off-gas. Effective bioprocesses for such applications will require detailed knowledge of the biological process mechanisms and advanced bioreactor technology than can be optimized for high productivity, as well as supporting upstream and downstream processes that will allow an effective integrated bioprocess. Of particular interest is the development of predictive models that can be used for process design and scaleup. In this program, a generic approach is taken so that there will be utility over a broad range of applications. In conjunction with the generic approach, model experimental systems that address real-world problems are used to verify the results.

  16. Food Service Fundamentals.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on food service fundamentals is designed to provide a general background in the basic aspects of the food service program in the Marine Corps; it is adaptable for nonmilitary instruction. Introductory materials include specific information for MCI…

  17. Unification of Fundamental Forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus; Taylor, Foreword by John C.

    2005-10-01

    Foreword John C. Taylor; 1. Unification of fundamental forces Abdus Salam; 2. History unfolding: an introduction to the two 1968 lectures by W. Heisenberg and P. A. M. Dirac Abdus Salam; 3. Theory, criticism, and a philosophy Werner Heisenberg; 4. Methods in theoretical physics Paul Adrian Maurice Dirac.

  18. Fundamentals of Diesel Engines.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the fundamentals of diesel engine mechanics. Addressed in the three individual units of the course are the following topics: basic principles of diesel mechanics; principles, mechanics, and…

  19. Reading Is Fundamental, 1977.

    ERIC Educational Resources Information Center

    Smithsonian Institution, Washington, DC. National Reading is Fun-damental Program.

    Reading Is Fundamental (RIF) is a national, nonprofit organization designed to motivate children to read by making a wide variety of inexpensive books available to them and allowing the children to choose and keep books that interest them. This annual report for 1977 contains the following information on the RIF project: an account of the…

  20. Fundamentals of soil science

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study guide provides comments and references for professional soil scientists who are studying for the soil science fundamentals exam needed as the first step for certification. The performance objectives were determined by the Soil Science Society of America's Council of Soil Science Examiners...

  1. Homeschooling and Religious Fundamentalism

    ERIC Educational Resources Information Center

    Kunzman, Robert

    2010-01-01

    This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to…

  2. Fundamentals of tribology

    SciTech Connect

    Suh, N.P.; Saka, N.

    1980-01-01

    This book presents the proceedings of the June 1978 International Conference on the Fundamentals of Tribology. The papers discuss the effects of surface topography and of the properties of materials on wear; friction, wear, and thermomechanical effects; wear mechanisms in metal processing; polymer wear; wear monitoring and prevention; and lubrication. (LCL)

  3. Fundamental research data base

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A fundamental research data base containing ground truth, image, and Badhwar profile feature data for 17 North Dakota, South Dakota, and Minnesota agricultural sites is described. Image data was provided for a minimum of four acquisition dates for each site and all four images were registered to one another.

  4. Laser Fundamentals and Experiments.

    ERIC Educational Resources Information Center

    Van Pelt, W. F.; And Others

    As a result of work performed at the Southwestern Radiological Health Laboratory with respect to lasers, this manual was prepared in response to the increasing use of lasers in high schools and colleges. It is directed primarily toward the high school instructor who may use the text for a short course in laser fundamentals. The definition of the…

  5. The Fundamental Property Relation.

    ERIC Educational Resources Information Center

    Martin, Joseph J.

    1983-01-01

    Discusses a basic equation in thermodynamics (the fundamental property relation), focusing on a logical approach to the development of the relation where effects other than thermal, compression, and exchange of matter with the surroundings are considered. Also demonstrates erroneous treatments of the relation in three well-known textbooks. (JN)

  6. Fundamentals of Library Instruction

    ERIC Educational Resources Information Center

    McAdoo, Monty L.

    2012-01-01

    Being a great teacher is part and parcel of being a great librarian. In this book, veteran instruction services librarian McAdoo lays out the fundamentals of the discipline in easily accessible language. Succinctly covering the topic from top to bottom, he: (1) Offers an overview of the historical context of library instruction, drawing on recent…

  7. Fundamental electrode kinetics

    NASA Technical Reports Server (NTRS)

    Elder, J. P.

    1968-01-01

    Report presents the fundamentals of electrode kinetics and the methods used in evaluating the characteristic parameters of rapid-charge transfer processes at electrode-electrolyte interfaces. The concept of electrode kinetics is outlined, followed by the principles underlying the experimental techniques for the investigation of electrode kinetics.

  8. Basic Publication Fundamentals.

    ERIC Educational Resources Information Center

    Savedge, Charles E., Ed.

    Designed for students who produce newspapers and newsmagazines in junior high, middle, and elementary schools, this booklet is both a scorebook and a fundamentals text. The scorebook provides realistic criteria for judging publication excellence at these educational levels. All the basics for good publications are included in the text of the…

  9. NASA's Advanced Environmental Barrier Coatings Development for SiC/SiC Ceramic Matrix Composites: Understanding Calcium Magnesium Alumino-Silicate (CMAS) Degradations and Resistance

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming

    2014-01-01

    Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is essential to the viability and reliability of the envisioned CMC engine component applications, ensuring integrated EBC-CMC system durability and designs are achievable for successful applications of the game-changing component technologies and lifing methodologies.This paper will emphasize recent NASA environmental barrier coating developments for SiCSiC turbine airfoil components, utilizing advanced coating compositions, state-of-the-art processing methods, and combined mechanical and environment testing and durability evaluations. The coating-CMC degradations in the engine fatigue-creep and operating environments are particularly complex; one of the important coating development aspects is to better understand engine environmental interactions and coating life debits, and we have particularly addressed the effect of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the durability of the environmental barrier coating systems, and how the temperature capability, stability and cyclic life of the candidate rare earth oxide and silicate coating systems will be impacted in the presence of the CMAS at high temperatures and under simulated heat flux conditions. Advanced environmental barrier coating systems, including HfO2-Si with rare earth dopant based bond coat systems, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

  10. New Views of the Moon II 2008-2018; An initiative to integrate new lunar information into our fundamental understanding of the Moon and the next stages of international lunar exploration.

    NASA Astrophysics Data System (ADS)

    Shearer, C.; Neal, C. R.; Jolliff, B. L.; Wieczorek, M. A.; Mackwell, S.; Lawrence, S.

    2015-10-01

    In 1998, the Curation and Analysis Planning Team for Extraterrestrial Materials (CAPTEM)sponsored a longterm initiative to improve our understanding of the Moon and its history by integrating all available types of data: in situ investigations, analyses of lunar samples, telescopic observations, and spacecraft datasets. This initiative, New Views of the Moon (NVM-I),was supported by NASA's Science Mission Directorate andthe Lunar and Planetary Institute and guided principally by Brad Jolliff, Charles Shearer,Mark Wieczorek,and Clive Neal. The goals of the original NVM-Iinitiative were (1) tosummarize new insights that have been gained about the Moon as a result of recent global data sets(Clementine, Lunar Prospector), and their integration with sample and other data;(2) to define current understanding of the Moon's geologic history, resources, and potential for scientific exploration; and (3) to communicate implications ofknowledge gained from research and exploration of the Moon for planetary science and exploration beyond the Moon. The NVM- Iinitiative ultimately involved contributions and data synthesis from over 100 individual scientists and engineers at numerous workshops and special sessions at worldwide scientific meetings.NVM-I culminated in a book "New Views of the Moon" published in 2006 as volume 60 of Reviews in Mineralogy and Geochemistry published by the Mineralogical Society of America. In 2012, the book was translated into Chinese.NVM-I went to press prior to analysis of the data from missions flown since 2000, and before the major discoveries from sample analyses made this century

  11. Individual differences in fundamental social motives.

    PubMed

    Neel, Rebecca; Kenrick, Douglas T; White, Andrew Edward; Neuberg, Steven L

    2016-06-01

    Motivation has long been recognized as an important component of how people both differ from, and are similar to, each other. The current research applies the biologically grounded fundamental social motives framework, which assumes that human motivational systems are functionally shaped to manage the major costs and benefits of social life, to understand individual differences in social motives. Using the Fundamental Social Motives Inventory, we explore the relations among the different fundamental social motives of Self-Protection, Disease Avoidance, Affiliation, Status, Mate Seeking, Mate Retention, and Kin Care; the relationships of the fundamental social motives to other individual difference and personality measures including the Big Five personality traits; the extent to which fundamental social motives are linked to recent life experiences; and the extent to which life history variables (e.g., age, sex, childhood environment) predict individual differences in the fundamental social motives. Results suggest that the fundamental social motives are a powerful lens through which to examine individual differences: They are grounded in theory, have explanatory value beyond that of the Big Five personality traits, and vary meaningfully with a number of life history variables. A fundamental social motives approach provides a generative framework for considering the meaning and implications of individual differences in social motivation. (PsycINFO Database Record PMID:26371400

  12. Advancing the understanding of the Sun-Earth interaction—the Climate and Weather of the Sun-Earth System (CAWSES) II program

    NASA Astrophysics Data System (ADS)

    Tsuda, Toshitaka; Shepherd, Marianna; Gopalswamy, Nat

    2015-12-01

    The Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) of the International Council for Science (ICSU) implemented an international collaborative program called Climate and Weather of the Sun-Earth System (CAWSES), which was active from 2004 to 2008; this was followed by the CAWSES II program during the period of 2009-2013. The CAWSES program was aimed at improving the understanding of the coupled solar-terrestrial system, with special emphasis placed on the short-term (weather) and long-term (climate) variability of solar activities and their effects on and responses of Geospace and Earth's environment. Following the successful implementation of CAWSES, the CAWSES II program pursued four fundamental questions addressing the way in which the coupled Sun-Earth system operates over time scales ranging from minutes to millennia, namely, (1) What are the solar influences on the Earth's climate? (2) How will Geospace respond to an altered climate? (3) How does short-term solar variability affect the Geospace environment? and (4) What is the Geospace response to variable inputs from the lower atmosphere? In addition to these four major tasks, the SCOSTEP and CAWSES promoted E-science and informatics activities including the creation of scientific databases and their effective utilization in solar-terrestrial physics research. Capacity building activities were also enhanced during CAWSES II, and this represented an important contribution of SCOSTEP to the world's solar-terrestrial physics community. This introductory paper provides an overview of CAWSES II activities and serves as a preface to the dedicated review papers summarizing the achievements of the program's four task groups (TGs) and the E-science component.

  13. DOE Fundamentals Handbook: Electrical Science, Volume 4

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive transformers; and electrical test components; batteries; AC and DC voltage regulators; instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  14. DOE Fundamentals Handbook: Mathematics, Volume 2

    SciTech Connect

    Not Available

    1992-06-01

    The Mathematics Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mathematics and its application to facility operation. The handbook includes a review of introductory mathematics and the concepts and functional use of algebra, geometry, trigonometry, and calculus. Word problems, equations, calculations, and practical exercises that require the use of each of the mathematical concepts are also presented. This information will provide personnel with a foundation for understanding and performing basic mathematical calculations that are associated with various DOE nuclear facility operations.

  15. DOE Fundamentals Handbook: Electrical Science, Volume 1

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  16. DOE Fundamentals Handbook: Electrical Science, Volume 3

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  17. DOE Fundamentals Handbook: Electrical Science, Volume 2

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  18. Fundamentals of Polarized Light

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael

    2003-01-01

    The analytical and numerical basis for describing scattering properties of media composed of small discrete particles is formed by the classical electromagnetic theory. Although there are several excellent textbooks outlining the fundamentals of this theory, it is convenient for our purposes to begin with a summary of those concepts and equations that are central to the subject of this book and will be used extensively in the following chapters. We start by formulating Maxwell's equations and constitutive relations for time- harmonic macroscopic electromagnetic fields and derive the simplest plane-wave solution that underlies the basic optical idea of a monochromatic parallel beam of light. This solution naturally leads to the introduction of such fundamental quantities as the refractive index and the Stokes parameters. Finally, we define the concept of a quasi-monochromatic beam of light and discuss its implications.

  19. Fundamentals of Geophysics

    NASA Astrophysics Data System (ADS)

    Frohlich, Cliff

    Choosing an intermediate-level geophysics text is always problematic: What should we teach students after they have had introductory courses in geology, math, and physics, but little else? Fundamentals of Geophysics is aimed specifically at these intermediate-level students, and the author's stated approach is to construct a text “using abundant diagrams, a simplified mathematical treatment, and equations in which the student can follow each derivation step-by-step.” Moreover, for Lowrie, the Earth is round, not flat—the “fundamentals of geophysics” here are the essential properties of our Earth the planet, rather than useful techniques for finding oil and minerals. Thus this book is comparable in both level and approach to C. M. R. Fowler's The Solid Earth (Cambridge University Press, 1990).

  20. Fundamental limits on EMC

    NASA Astrophysics Data System (ADS)

    Showers, R. M.; Lin, S.-Y.; Schulz, R. B.

    1981-02-01

    Both fundamental and state-of-the-art limits are treated with emphasis on the former. Fundamental limits result from both natural and man-made electromagnetic noise which then affect two basic ratios, signal-to-noise (S/N) and extraneous-input-to-noise (I/N). Tolerable S/N values are discussed for both digital and analog communications systems. These lead to tolerable signal-to-extraneous-input (S/I) ratios, again for digital and analog communications systems, as well as radar and sonar. State-of-the-art limits for transmitters include RF noise emission, spurious emissions, and intermodulation. Receiver limits include adjacent-channel interactions, image, IF, and other spurious responses, including cross modulation, intermodulation, and desensitization. Unintentional emitters and receivers are also discussed. Coupling limitations between undesired sources and receptors are considered from mechanisms including radiation, induction, and conduction.

  1. Fundamental studies in geodynamics

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.; Hager, B. H.; Kanamori, H.

    1981-01-01

    Research in fundamental studies in geodynamics continued in a number of fields including seismic observations and analysis, synthesis of geochemical data, theoretical investigation of geoid anomalies, extensive numerical experiments in a number of geodynamical contexts, and a new field seismic volcanology. Summaries of work in progress or completed during this report period are given. Abstracts of publications submitted from work in progress during this report period are attached as an appendix.

  2. Value of Fundamental Science

    NASA Astrophysics Data System (ADS)

    Burov, Alexey

    Fundamental science is a hard, long-term human adventure that has required high devotion and social support, especially significant in our epoch of Mega-science. The measure of this devotion and this support expresses the real value of the fundamental science in public opinion. Why does fundamental science have value? What determines its strength and what endangers it? The dominant answer is that the value of science arises out of curiosity and is supported by the technological progress. Is this really a good, astute answer? When trying to attract public support, we talk about the ``mystery of the universe''. Why do these words sound so attractive? What is implied by and what is incompatible with them? More than two centuries ago, Immanuel Kant asserted an inseparable entanglement between ethics and metaphysics. Thus, we may ask: which metaphysics supports the value of scientific cognition, and which does not? Should we continue to neglect the dependence of value of pure science on metaphysics? If not, how can this issue be addressed in the public outreach? Is the public alienated by one or another message coming from the face of science? What does it mean to be politically correct in this sort of discussion?

  3. Fundamental Limits to Cellular Sensing

    NASA Astrophysics Data System (ADS)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  4. Fundamental studies of fusion plasmas

    SciTech Connect

    Aamodt, R.E.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R.; Russell, D.A.

    1992-05-26

    The major portion of this program is devoted to critical ICH phenomena. The topics include edge physics, fast wave propagation, ICH induced high frequency instabilities, and a preliminary antenna design for Ignitor. This research was strongly coordinated with the world's experimental and design teams at JET, Culham, ORNL, and Ignitor. The results have been widely publicized at both general scientific meetings and topical workshops including the speciality workshop on ICRF design and physics sponsored by Lodestar in April 1992. The combination of theory, empirical modeling, and engineering design in this program makes this research particularly important for the design of future devices and for the understanding and performance projections of present tokamak devices. Additionally, the development of a diagnostic of runaway electrons on TEXT has proven particularly useful for the fundamental understanding of energetic electron confinement. This work has led to a better quantitative basis for quasilinear theory and the role of magnetic vs. electrostatic field fluctuations on electron transport. An APS invited talk was given on this subject and collaboration with PPPL personnel was also initiated. Ongoing research on these topics will continue for the remainder fo the contract period and the strong collaborations are expected to continue, enhancing both the relevance of the work and its immediate impact on areas needing critical understanding.

  5. Fundamental research data base

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A fundamental research data base was created on a single 9-track 1600 BPI tape containing ground truth, image, and Badhwar profile feature data for 17 North Dakota, South Dakota, and Minnesota agricultural sites. Each site is 5x6 nm in area. Image data has been provided for a minimum of four acquisition dates for each site. All four images have been registered to one another. A list of the order of the files on tape and the dates of acquisition is provided.

  6. Cognition is … Fundamentally Cultural

    PubMed Central

    Bender, Andrea; Beller, Sieghard

    2013-01-01

    A prevailing concept of cognition in psychology is inspired by the computer metaphor. Its focus on mental states that are generated and altered by information input, processing, storage and transmission invites a disregard for the cultural dimension of cognition, based on three (implicit) assumptions: cognition is internal, processing can be distinguished from content, and processing is independent of cultural background. Arguing against each of these assumptions, we point out how culture may affect cognitive processes in various ways, drawing on instances from numerical cognition, ethnobiological reasoning, and theory of mind. Given the pervasive cultural modulation of cognition—on all of Marr’s levels of description—we conclude that cognition is indeed fundamentally cultural, and that consideration of its cultural dimension is essential for a comprehensive understanding. PMID:25379225

  7. DOE fundamentals handbook: Material science. Volume 1

    SciTech Connect

    Not Available

    1993-01-01

    The Mechanical Science Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mechanical components and mechanical science. The handbook includes information on diesel engines, heat exchangers, pumps, valves, and miscellaneous mechanical components. This information will provide personnel with a foundation for understanding the construction and operation of mechanical components that are associated with various DOE nuclear facility operations and maintenance.

  8. DOE fundamentals handbook: Mechanical science. Volume 2

    SciTech Connect

    Not Available

    1993-01-01

    The Mechanical Science Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mechanical components and mechanical science. The handbook includes information diesel engines, heat exchangers, pumps, valves, and miscellaneous mechanical components. This information will provide personnel with a foundation for understanding the construction and operation of mechanical components that are associated with various DOE nuclear facility operations and maintenance.

  9. Recent advances in the understanding and care of familial hypercholesterolaemia: significance of the biology and therapeutic regulation of proprotein convertase subtilisin/kexin type 9.

    PubMed

    Page, Michael M; Stefanutti, Claudia; Sniderman, Allan; Watts, Gerald F

    2015-07-01

    Familial hypercholesterolaemia (FH) is an autosomal co-dominant disorder that markedly raises plasma low-density lipoprotein-cholesterol (LDL-C) concentration, causing premature atherosclerotic coronary artery disease (CAD). FH has recently come under intense focus and, although there is general consensus in recent international guidelines regarding diagnosis and treatment, there is debate about the value of genetic studies. Genetic testing can be cost-effective as part of cascade screening in dedicated centres, but the full mutation spectrum responsible for FH has not been established in many populations, and its use in primary care is not at present logistically feasible. Whether using genetic testing or not, cholesterol screening of family members of index patients with an abnormally raised LDL-C must be used to determine the need for early treatment to prevent the development of CAD. The metabolic defects in FH extend beyond LDL, and may affect triacylglycerol-rich and high-density lipoproteins, lipoprotein(a) and oxidative stress. Achievement of the recommended targets for LDL-C with current treatments is difficult, but this may be resolved by new drug therapies. Lipoprotein apheresis remains an effective treatment for severe FH and, although expensive, it costs less than the two recently introduced orphan drugs (lomitapide and mipomersen) for homozygous FH. Recent advances in understanding of the biology of proprotein convertase subtilisin/kexin type 9 (PCSK9) have further elucidated the regulation of lipoprotein metabolism and led to new drugs for effectively treating hypercholesterolaemia in FH and related conditions, as well as for treating many patients with statin intolerance. The mechanisms of action of PCSK9 inhibitors on lipoprotein metabolism and atherosclerosis, as well as their impact on cardiovascular outcomes and cost-effectiveness, remain to be established. PMID:25881720

  10. The venom gland transcriptome of the Desert Massasauga Rattlesnake (Sistrurus catenatus edwardsii): towards an understanding of venom composition among advanced snakes (Superfamily Colubroidea)

    PubMed Central

    Pahari, Susanta; Mackessy, Stephen P; Kini, R Manjunatha

    2007-01-01

    Background Snake venoms are complex mixtures of pharmacologically active proteins and peptides which belong to a small number of superfamilies. Global cataloguing of the venom transcriptome facilitates the identification of new families of toxins as well as helps in understanding the evolution of venom proteomes. Results We have constructed a cDNA library of the venom gland of a threatened rattlesnake (a pitviper), Sistrurus catenatus edwardsii (Desert Massasauga), and sequenced 576 ESTs. Our results demonstrate a high abundance of serine proteinase and metalloproteinase transcripts, indicating that the disruption of hemostasis is a principle mechanism of action of the venom. In addition to the transcripts encoding common venom proteins, we detected two varieties of low abundance unique transcripts in the library; these encode for three-finger toxins and a novel toxin possibly generated from the fusion of two genes. We also observed polyadenylated ribosomal RNAs in the venom gland library, an interesting preliminary obsevation of this unusual phenomenon in a reptilian system. Conclusion The three-finger toxins are characteristic of most elapid venoms but are rare in viperid venoms. We detected several ESTs encoding this group of toxins in this study. We also observed the presence of a transcript encoding a fused protein of two well-characterized toxins (Kunitz/BPTI and Waprins), and this is the first report of this kind of fusion in a snake toxin transcriptome. We propose that these new venom proteins may have ancillary functions for envenomation. The presence of a fused toxin indicates that in addition to gene duplication and accelerated evolution, exon shuffling or transcriptional splicing may also contribute to generating the diversity of toxins and toxin isoforms observed among snake venoms. The detection of low abundance toxins, as observed in this and other studies, indicates a greater compositional similarity of venoms (though potency will differ) among

  11. Fundamental studies on passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1993-06-01

    Using photoelectrochemical impedance and admittance spectroscopies, a fundamental and quantitative understanding of the mechanisms for the growth and breakdown of passive films on metal and alloy surfaces in contact with aqueous environments is being developed. A point defect model has been extended to explain the breakdown of passive films, leading to pitting and crack growth and thus development of damage due to localized corrosion.

  12. A Fundamental Theorem on Particle Acceleration

    SciTech Connect

    Xie, Ming

    2003-05-01

    A fundamental theorem on particle acceleration is derived from the reciprocity principle of electromagnetism and a rigorous proof of the theorem is presented. The theorem establishes a relation between acceleration and radiation, which is particularly useful for insightful understanding of and practical calculation about the first order acceleration in which energy gain of the accelerated particle is linearly proportional to the accelerating field.

  13. Course Objectives: Electronic Fundamentals, EL16.

    ERIC Educational Resources Information Center

    Wilson, David H.

    The general objective, recommended text, and specific objectives of a course titled "Electronic Fundamentals," as offered at St. Lawrence College of Applied Arts and Technology, are provided. The general objective of the course is "to acquire an understanding of diodes, transistors, and tubes, and so be able to analyze the operation of single…

  14. Fundamental approaches in molecular biology for communication sciences and disorders

    PubMed Central

    Bartlett, Rebecca; Jetté, Marie E; King, Suzanne N.; Schaser, Allison; Thibeault, Susan L.

    2012-01-01

    Purpose This contemporary tutorial will introduce general principles of molecular biology, common DNA, RNA and protein assays and their relevance in the field of communication sciences and disorders (CSD). Methods Over the past two decades, knowledge of the molecular pathophysiology of human disease has increased at a remarkable pace. Most of this progress can be attributed to concomitant advances in basic molecular biology and, specifically, the development of an ever-expanding armamentarium of technologies for analysis of DNA, RNA and protein structure and function. Details of these methodologies, their limitations and examples from the CSD literature are presented. Results/Conclusions The use of molecular biology techniques in the fields of speech, language and hearing sciences is increasing, facilitating the need for an understanding of molecular biology fundamentals and common experimental assays. PMID:22232415

  15. Toward a Student-Centered Understanding of Intensive Writing and Writing-to-Learn in the Spanish Major: An Examination of Advanced L2 Spanish Students' Learning in the Writing-Intensive Spanish Content Course

    ERIC Educational Resources Information Center

    Strong, Robert Marvin

    2009-01-01

    The purpose of this study is to build upon our understanding of the place and value of writing in the advanced foreign language curriculum. Specifically, the study examines how students in writing-intensive Spanish-major courses are affected by the writing-intensive (WI) requirement at the University of Minnesota. Writing-Across-the-Curriculum…

  16. Fundamental Aeronautics Program

    NASA Technical Reports Server (NTRS)

    Misra, Ajay

    2009-01-01

    The Overarching Mission of NASA's Aeronautics Research Mission Directorate (ARMD) is: To advance U.S. technological leadership in aeronautics in partnership with industry, academia, and other government agencies that conduct aeronautics-related research. ARMD supports the Agency's goal of developing a balanced overall program of science, exploration, and aeronautics, and ARMD's research plans also directly support the National Aeronautics R&D Policy and accompanying Executive Order 131419.

  17. Unification of Fundamental Forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus

    1990-05-01

    This is an expanded version of the third Dirac Memorial Lecture, given in 1988 by the Nobel Laureate Abdus Salam. Salam's lecture presents an overview of the developments in modern particle physics from its inception at the turn of the century to the present theories seeking to unify all the fundamental forces. In addition, two previously unpublished lectures by Paul Dirac, and Werner Heisenberg are included. These lectures provide a fascinating insight into their approach to research and the developments in particle physics at that time. Nonspecialists, undergraduates and researchers will find this a fascinating book. It contains a clear introduction to the major themes of particle physics and cosmology by one of the most distinguished contemporary physicists.

  18. Wall of fundamental constants

    SciTech Connect

    Olive, Keith A.; Peloso, Marco; Uzan, Jean-Philippe

    2011-02-15

    We consider the signatures of a domain wall produced in the spontaneous symmetry breaking involving a dilatonlike scalar field coupled to electromagnetism. Domains on either side of the wall exhibit slight differences in their respective values of the fine-structure constant, {alpha}. If such a wall is present within our Hubble volume, absorption spectra at large redshifts may or may not provide a variation in {alpha} relative to the terrestrial value, depending on our relative position with respect to the wall. This wall could resolve the contradiction between claims of a variation of {alpha} based on Keck/Hires data and of the constancy of {alpha} based on Very Large Telescope data. We derive the properties of the wall and the parameters of the underlying microscopic model required to reproduce the possible spatial variation of {alpha}. We discuss the constraints on the existence of the low-energy domain wall and describe its observational implications concerning the variation of the fundamental constants.

  19. Fundamentals in Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Basdevant, Jean-Louis, Rich, James, Spiro, Michael

    This course on nuclear physics leads the reader to the exploration of the field from nuclei to astrophysical issues. Much nuclear phenomenology can be understood from simple arguments such as those based on the Pauli principle and the Coulomb barrier. This book is concerned with extrapolating from such arguments and illustrating nuclear systematics with experimental data. Starting with the basic concepts in nuclear physics, nuclear models, and reactions, the book covers nuclear decays and the fundamental electro-weak interactions, radioactivity, and nuclear energy. After the discussions of fission and fusion leading into nuclear astrophysics, there is a presentation of the latest ideas about cosmology. As a primer this course will lay the foundations for more specialized subjects. This book emerged from a series of topical courses the authors delivered at the Ecole Polytechnique and will be useful for graduate students and for scientists in a variety of fields.

  20. Fundamentals of battery dynamics

    NASA Astrophysics Data System (ADS)

    Jossen, Andreas

    Modern applications, such as wireless communication systems or hybrid electric vehicles operate at high power fluctuations. For some applications, where the power frequencies are high (above some 10 or 100 Hz) it is possible to filter the high frequencies using passive components; yet this results in additional costs. In other applications, where the dynamic time constants are in the range up to some seconds, filtering cannot be done. Batteries are hence operated with the dynamic loads. But what happens under these dynamic operation conditions? This paper describes the fundamentals of the dynamic characteristics of batteries in a frequency range from some MHz down to the mHz range. As the dynamic behaviour depends on the actual state of charge (SOC) and the state of health (SOH), it is possible to gain information on the battery state by analysing the dynamic behaviour. High dynamic loads can influence the battery temperature, the battery performance and the battery lifetime.

  1. Fundamentals of zoological scaling

    NASA Astrophysics Data System (ADS)

    Lin, Herbert

    1982-01-01

    Most introductory physics courses emphasize highly idealized problems with unique well-defined answers. Though many textbooks complement these problems with estimation problems, few books present anything more than an elementary discussion of scaling. This paper presents some fundamentals of scaling in the zoological domain—a domain complex by any standard, but one also well suited to illustrate the power of very simple physical ideas. We consider the following animal characteristics: skeletal weight, speed of running, height and range of jumping, food consumption, heart rate, lifetime, locomotive efficiency, frequency of wing flapping, and maximum sizes of animals that fly and hover. These relationships are compared to zoological data and everyday experience, and match reasonably well.

  2. Fundamentals of gel dosimeters

    NASA Astrophysics Data System (ADS)

    McAuley, K. B.; Nasr, A. T.

    2013-06-01

    Fundamental chemical and physical phenomena that occur in Fricke gel dosimeters, polymer gel dosimeters, micelle gel dosimeters and genipin gel dosimeters are discussed. Fricke gel dosimeters are effective even though their radiation sensitivity depends on oxygen concentration. Oxygen contamination can cause severe problems in polymer gel dosimeters, even when THPC is used. Oxygen leakage must be prevented between manufacturing and irradiation of polymer gels, and internal calibration methods should be used so that contamination problems can be detected. Micelle gel dosimeters are promising due to their favourable diffusion properties. The introduction of micelles to gel dosimetry may open up new areas of dosimetry research wherein a range of water-insoluble radiochromic materials can be explored as reporter molecules.

  3. Bioinspired Materials: Bioinspired Interfacial Materials with Enhanced Drop Mobility: From Fundamentals to Multifunctional Applications (Small 14/2016).

    PubMed

    Hao, Chonglei; Liu, Yahua; Chen, Xuemei; Li, Jing; Zhang, Mei; Zhao, Yanhua; Wang, Zuankai

    2016-04-01

    The development of bioinspired interfacial materials with enhanced drop mobility that mimic the innate functionalities of nature will have significant impact on energy, environment, and global healthcare. On page 1825, Z. Wang and co-workers highlight recent advances in the fundamental understanding, as well as practical applications of bio-inspired interfacial materials, with an emphasis on drop bouncing and jumping behaviors. PMID:27061454

  4. Fundamental Principles of Proper Space Kinematics

    NASA Astrophysics Data System (ADS)

    Wade, Sean

    It is desirable to understand the movement of both matter and energy in the universe based upon fundamental principles of space and time. Time dilation and length contraction are features of Special Relativity derived from the observed constancy of the speed of light. Quantum Mechanics asserts that motion in the universe is probabilistic and not deterministic. While the practicality of these dissimilar theories is well established through widespread application inconsistencies in their marriage persist, marring their utility, and preventing their full expression. After identifying an error in perspective the current theories are tested by modifying logical assumptions to eliminate paradoxical contradictions. Analysis of simultaneous frames of reference leads to a new formulation of space and time that predicts the motion of both kinds of particles. Proper Space is a real, three-dimensional space clocked by proper time that is undergoing a densification at the rate of c. Coordinate transformations to a familiar object space and a mathematical stationary space clarify the counterintuitive aspects of Special Relativity. These symmetries demonstrate that within the local universe stationary observers are a forbidden frame of reference; all is in motion. In lieu of Quantum Mechanics and Uncertainty the use of the imaginary number i is restricted for application to the labeling of mass as either material or immaterial. This material phase difference accounts for both the perceived constant velocity of light and its apparent statistical nature. The application of Proper Space Kinematics will advance more accurate representations of microscopic, oscopic, and cosmological processes and serve as a foundation for further study and reflection thereafter leading to greater insight.

  5. Fundamentals of cancer metabolism

    PubMed Central

    DeBerardinis, Ralph J.; Chandel, Navdeep S.

    2016-01-01

    Tumors reprogram pathways of nutrient acquisition and metabolism to meet the bioenergetic, biosynthetic, and redox demands of malignant cells. These reprogrammed activities are now recognized as hallmarks of cancer, and recent work has uncovered remarkable flexibility in the specific pathways activated by tumor cells to support these key functions. In this perspective, we provide a conceptual framework to understand how and why metabolic reprogramming occurs in tumor cells, and the mechanisms linking altered metabolism to tumorigenesis and metastasis. Understanding these concepts will progressively support the development of new strategies to treat human cancer. PMID:27386546

  6. Fundamentals of cancer metabolism.

    PubMed

    DeBerardinis, Ralph J; Chandel, Navdeep S

    2016-05-01

    Tumors reprogram pathways of nutrient acquisition and metabolism to meet the bioenergetic, biosynthetic, and redox demands of malignant cells. These reprogrammed activities are now recognized as hallmarks of cancer, and recent work has uncovered remarkable flexibility in the specific pathways activated by tumor cells to support these key functions. In this perspective, we provide a conceptual framework to understand how and why metabolic reprogramming occurs in tumor cells, and the mechanisms linking altered metabolism to tumorigenesis and metastasis. Understanding these concepts will progressively support the development of new strategies to treat human cancer. PMID:27386546

  7. Weather Fundamentals: Clouds. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  8. Fundamentals of Creativity

    ERIC Educational Resources Information Center

    Beghetto, Ronald A.; Kaufman, James C.

    2013-01-01

    Creativity has become a hot topic in education. From President Barack Obama to Amazon's Jeff Bezos to "Newsweek" magazine, business leaders, major media outlets, government officials, and education policy makers are increasingly advocating including student creativity in the curriculum. But without a clear understanding of the nature of creativity…

  9. Weather Fundamentals: Meteorology. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

  10. Weather Fundamentals: Wind. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) describes the roles of the sun, temperature, and air pressure in creating the incredible power…

  11. Fundamentals of Outdoor Enjoyment.

    ERIC Educational Resources Information Center

    Mitchell, Jim; Fear, Gene

    The purpose of this preventive search and rescue teachers guide is to help high school aged youth understand the complexities and priorities necessary to manage a human body in outdoor environments and the value of planning ahead to have on hand the skills and equipment needed for outdoor survival, comfort, and enjoyment. Separate sections present…

  12. Dark Energy: A Crisis for Fundamental Physics

    ScienceCinema

    Stubbs, Christopher [Harvard University, Cambridge, Massachusetts, USA

    2010-09-01

    Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talk will present experiments and observations that are exploring this issue.

  13. Fundamentals of Pharmacogenetics in Personalized, Precision Medicine.

    PubMed

    Valdes, Roland; Yin, DeLu Tyler

    2016-09-01

    This article introduces fundamental principles of pharmacogenetics as applied to personalized and precision medicine. Pharmacogenetics establishes relationships between pharmacology and genetics by connecting phenotypes and genotypes in predicting the response of therapeutics in individual patients. We describe differences between precision and personalized medicine and relate principles of pharmacokinetics and pharmacodynamics to applications in laboratory medicine. We also review basic principles of pharmacogenetics, including its evolution, how it enables the practice of personalized therapeutics, and the role of the clinical laboratory. These fundamentals are a segue for understanding specific clinical applications of pharmacogenetics described in subsequent articles in this issue. PMID:27514461

  14. GRBs and Fundamental Physics

    NASA Astrophysics Data System (ADS)

    Petitjean, Patrick; Wang, F. Y.; Wu, X. F.; Wei, J. J.

    2016-02-01

    Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So, they are unique tools to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal evolution of the Universe. First, they can be used to constrain the history of cosmic acceleration and the evolution of dark energy in a redshift range hardly achievable by other cosmological probes. Second, long GRBs are believed to be formed by collapse of massive stars. So they can be used to derive the high-redshift star formation rate, which can not be probed by current observations. Moreover, the use of GRBs as cosmological tools could unveil the reionization history and metal evolution of the Universe, the intergalactic medium (IGM) properties and the nature of first stars in the early universe. But beyond that, the GRB high-energy photons can be applied to constrain Lorentz invariance violation (LIV) and to test Einstein's Equivalence Principle (EEP). In this paper, we review the progress on the GRB cosmology and fundamental physics probed by GRBs.

  15. Fundamentals of Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Tang, C. L.

    2005-06-01

    Quantum mechanics has evolved from a subject of study in pure physics to one with a wide range of applications in many diverse fields. The basic concepts of quantum mechanics are explained in this book in a concise and easy-to-read manner emphasising applications in solid state electronics and modern optics. Following a logical sequence, the book is focused on the key ideas and is conceptually and mathematically self-contained. The fundamental principles of quantum mechanics are illustrated by showing their application to systems such as the hydrogen atom, multi-electron ions and atoms, the formation of simple organic molecules and crystalline solids of practical importance. It leads on from these basic concepts to discuss some of the most important applications in modern semiconductor electronics and optics. Containing many homework problems and worked examples, the book is suitable for senior-level undergraduate and graduate level students in electrical engineering, materials science and applied physics. Clear exposition of quantum mechanics written in a concise and accessible style Precise physical interpretation of the mathematical foundations of quantum mechanics Illustrates the important concepts and results by reference to real-world examples in electronics and optoelectronics Contains homeworks and worked examples, with solutions available for instructors

  16. Overlay accuracy fundamentals

    NASA Astrophysics Data System (ADS)

    Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

    2012-03-01

    Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to < 0.5nm, it becomes crucial to include also systematic error contributions which affect the accuracy of the metrology. Here we discuss fundamental aspects of overlay accuracy and a methodology to improve accuracy significantly. We identify overlay mark imperfections and their interaction with the metrology technology, as the main source of overlay inaccuracy. The most important type of mark imperfection is mark asymmetry. Overlay mark asymmetry leads to a geometrical ambiguity in the definition of overlay, which can be ~1nm or less. It is shown theoretically and in simulations that the metrology may enhance the effect of overlay mark asymmetry significantly and lead to metrology inaccuracy ~10nm, much larger than the geometrical ambiguity. The analysis is carried out for two different overlay metrology technologies: Imaging overlay and DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

  17. Ergonomics: A bridge between fundamentals and applied research

    PubMed Central

    Ghosh, Subrata; Bagchi, Anandi; Sen, Devashish; Bandyopadhyay, Pathikrit

    2011-01-01

    Ergonomics is becoming a subject of applying fundamentals on anthropocentric dimensions for holistic welfare. The so-called conflict between Basic science and Applied research finds one of its edges in Ergonomics. Be it cutting-edge technology or frontiers of scientific innovation–all start from understanding basic scientific aptitude and skill, and the best way to get familiar with the situation is practicing basic science again and again at a regular basis. Ergonomics is diversified in such paradigms that truly set an example of such harmony between two apparently never-ending straight lines. If the spirit of Science is true human welfare, be it in the form of environmental development, machine development, technological advancement, human resource development, or development of consecutive interfaces between these components, Participatory Ergonomics is one of the vivid examples of such conglomeration. Although fundamental science may appear to be of very little practical significance, it turns out that eventually it has far greater impact on human society than much of the so-called “applied research.” PMID:21808495

  18. Ergonomics: A bridge between fundamentals and applied research.

    PubMed

    Ghosh, Subrata; Bagchi, Anandi; Sen, Devashish; Bandyopadhyay, Pathikrit

    2011-01-01

    Ergonomics is becoming a subject of applying fundamentals on anthropocentric dimensions for holistic welfare. The so-called conflict between Basic science and Applied research finds one of its edges in Ergonomics. Be it cutting-edge technology or frontiers of scientific innovation-all start from understanding basic scientific aptitude and skill, and the best way to get familiar with the situation is practicing basic science again and again at a regular basis. Ergonomics is diversified in such paradigms that truly set an example of such harmony between two apparently never-ending straight lines. If the spirit of Science is true human welfare, be it in the form of environmental development, machine development, technological advancement, human resource development, or development of consecutive interfaces between these components, Participatory Ergonomics is one of the vivid examples of such conglomeration. Although fundamental science may appear to be of very little practical significance, it turns out that eventually it has far greater impact on human society than much of the so-called "applied research." PMID:21808495

  19. Solar astrophysical fundamental parameters

    NASA Astrophysics Data System (ADS)

    Meftah, M.; Irbah, A.; Hauchecorne, A.

    2014-08-01

    The accurate determination of the solar photospheric radius has been an important problem in astronomy for many centuries. From the measurements made by the PICARD spacecraft during the transit of Venus in 2012, we obtained a solar radius of 696,156±145 kilometres. This value is consistent with recent measurements carried out atmosphere. This observation leads us to propose a change of the canonical value obtained by Arthur Auwers in 1891. An accurate value for total solar irradiance (TSI) is crucial for the Sun-Earth connection, and represents another solar astrophysical fundamental parameter. Based on measurements collected from different space instruments over the past 35 years, the absolute value of the TSI, representative of a quiet Sun, has gradually decreased from 1,371W.m-2 in 1978 to around 1,362W.m-2 in 2013, mainly due to the radiometers calibration differences. Based on the PICARD data and in agreement with Total Irradiance Monitor measurements, we predicted the TSI input at the top of the Earth's atmosphere at a distance of one astronomical unit (149,597,870 kilometres) from the Sun to be 1,362±2.4W.m-2, which may be proposed as a reference value. To conclude, from the measurements made by the PICARD spacecraft, we obtained a solar photospheric equator-to-pole radius difference value of 5.9±0.5 kilometres. This value is consistent with measurements made by different space instruments, and can be given as a reference value.

  20. Fundamentals of polymeric materials

    SciTech Connect

    Shilling, M.S.

    1998-12-31

    The polymer industry is a young industry that has undergone tremendous growth and change over the last sixty years. Many important discoveries in polymer science have been accidental. Most of the learning has been by trial and error and most of the understanding is still basically empirical--make a polymer material or compound and then put it to the test to study what it is and how it performs. This article provides an overview of what polymers and polymer compounds are, why they behave as they do, and it discusses several examples of failures of rubber and plastic components.

  1. Understanding Space, Understanding Citizenship

    ERIC Educational Resources Information Center

    Fouberg, Erin Hogan

    2002-01-01

    In this time of geopolitical uncertainty, one question that arises repeatedly is how will citizenship be affected by changes in sovereignty? This paper uses the concepts of spaces of dependence and spaces of engagement to understand both formal and substantive citizenship on American Indian reservations in the United States. By studying the…

  2. Understanding Readers' Differing Understandings

    ERIC Educational Resources Information Center

    Kucer, Stephen B.

    2015-01-01

    This research examines the characteristics of reader understandings that vary from those stated in the text. Eighty-seven fourth graders orally read complex academic literary and scientific texts, followed by probed retellings. Retold ideas not directly supported by, or reflective of, the texts were identified. These differing understandings…

  3. EO-based lake-ice cover and surface temperature products: Advancing process understanding and modeling capabilities of lake-atmosphere interactions in cold regions

    NASA Astrophysics Data System (ADS)

    Duguay, C. R.; Kheyrollah Pour, H.; Ochilov, S.

    2011-12-01

    operational agencies, and the requirements of the operational user community to better characterize river-ice (and glacier temporary lakes) dynamics in flood forecasting models at the basin scale. This paper presents recent results on the development and evaluation of EO-based lake ice cover and LST products for future NWP/RCM experiments, and comparison with output from numerical lake models using Great Bear Lake (GBL) and Great Slave Lake (GSL), Canada, as test sites. Lake ice cover fraction estimates derived from Radarsat-1 imagery using the iterative region-growing using semantics as the core algorithm of the MAGIC (MAp Guided Ice-Classification) software are comparable to those determined through visual interpretation by expert ice analysts. Mean daily LST estimates from MODIS (Terra/Aqua satellites) are shown to be overall in good agreement with LSTs estimated with two lake models, with larger differences during the ice cover season than the open water season. Implications of these results in advancing our understanding of ice thermodynamics and the open-water thermal regime of the two large lakes, and for improving lake schemes currently used in NWP models and RCMs are also discussed.

  4. Fundamentals of neurogastroenterology

    PubMed Central

    Wood, J; Alpers, D; Andrews, P

    1999-01-01

    Current concepts and basic principles of neurogastroenterology in relation to functional gastrointestinal disorders are reviewed. Neurogastroenterology is emphasized as a new and advancing subspecialty of clinical gastroenterology and digestive science. As such, it embraces the investigative sciences dealing with functions, malfunctions, and malformations in the brain and spinal cord, and the sympathetic, parasympathetic and enteric divisions of the autonomic innervation of the digestive tract. Somatomotor systems are included insofar as pharyngeal phases of swallowing and pelvic floor involvement in defecation, continence, and pelvic pain are concerned. Inclusion of basic physiology of smooth muscle, mucosal epithelium, and the enteric immune system in the neurogastroenterologic domain relates to requirements for compatibility with neural control mechanisms. Psychologic and psychiatric relations to functional gastrointestinal disorders are included because they are significant components of neurogastroenterology, especially in relation to projections of discomfort and pain to the digestive tract.


Keywords: enteric nervous system; brain-gut axis; autonomic nervous system; nausea; gut motility; mast cells; gastrointestinal pain; Rome II PMID:10457039

  5. Fundamentals of phosphate transfer.

    PubMed

    Kirby, Anthony J; Nome, Faruk

    2015-07-21

    Historically, the chemistry of phosphate transfer-a class of reactions fundamental to the chemistry of Life-has been discussed almost exclusively in terms of the nucleophile and the leaving group. Reactivity always depends significantly on both factors; but recent results for reactions of phosphate triesters have shown that it can also depend strongly on the nature of the nonleaving or "spectator" groups. The extreme stabilities of fully ionised mono- and dialkyl phosphate esters can be seen as extensions of the same effect, with one or two triester OR groups replaced by O(-). Our chosen lead reaction is hydrolysis-phosphate transfer to water: because water is the medium in which biological chemistry takes place; because the half-life of a system in water is an accepted basic index of stability; and because the typical mechanisms of hydrolysis, with solvent H2O providing specific molecules to act as nucleophiles and as general acids or bases, are models for reactions involving better nucleophiles and stronger general species catalysts. Not least those available in enzyme active sites. Alkyl monoester dianions compete with alkyl diester monoanions for the slowest estimated rates of spontaneous hydrolysis. High stability at physiological pH is a vital factor in the biological roles of organic phosphates, but a significant limitation for experimental investigations. Almost all kinetic measurements of phosphate transfer reactions involving mono- and diesters have been followed by UV-visible spectroscopy using activated systems, conveniently compounds with good leaving groups. (A "good leaving group" OR* is electron-withdrawing, and can be displaced to generate an anion R*O(-) in water near pH 7.) Reactivities at normal temperatures of P-O-alkyl derivatives-better models for typical biological substrates-have typically had to be estimated: by extended extrapolation from linear free energy relationships, or from rate measurements at high temperatures. Calculation is free

  6. Fundamental Vocabulary Selection Based on Word Familiarity

    NASA Astrophysics Data System (ADS)

    Sato, Hiroshi; Kasahara, Kaname; Kanasugi, Tomoko; Amano, Shigeaki

    This paper proposes a new method for selecting fundamental vocabulary. We are presently constructing the Fundamental Vocabulary Knowledge-base of Japanese that contains integrated information on syntax, semantics and pragmatics, for the purposes of advanced natural language processing. This database mainly consists of a lexicon and a treebank: Lexeed (a Japanese Semantic Lexicon) and the Hinoki Treebank. Fundamental vocabulary selection is the first step in the construction of Lexeed. The vocabulary should include sufficient words to describe general concepts for self-expandability, and should not be prohibitively large to construct and maintain. There are two conventional methods for selecting fundamental vocabulary. The first is intuition-based selection by experts. This is the traditional method for making dictionaries. A weak point of this method is that the selection strongly depends on personal intuition. The second is corpus-based selection. This method is superior in objectivity to intuition-based selection, however, it is difficult to compile a sufficiently balanced corpora. We propose a psychologically-motivated selection method that adopts word familiarity as the selection criterion. Word familiarity is a rating that represents the familiarity of a word as a real number ranging from 1 (least familiar) to 7 (most familiar). We determined the word familiarity ratings statistically based on psychological experiments over 32 subjects. We selected about 30,000 words as the fundamental vocabulary, based on a minimum word familiarity threshold of 5. We also evaluated the vocabulary by comparing its word coverage with conventional intuition-based and corpus-based selection over dictionary definition sentences and novels, and demonstrated the superior coverage of our lexicon. Based on this, we conclude that the proposed method is superior to conventional methods for fundamental vocabulary selection.

  7. DOE fundamentals handbook: Material science. Volume 1

    SciTech Connect

    Not Available

    1993-01-01

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the structure and properties of metals. This volume contains the two modules: structure of metals (bonding, common lattic types, grain structure/boundary, polymorphis, alloys, imperfections in metals) and properties of metals (stress, strain, Young modulus, stress-strain relation, physical properties, working of metals, corrosion, hydrogen embrittlement, tritium/material compatibility).

  8. Tracing the Construction of Mathematical Activity with an Advanced Graphing Calculator to Understand the Roles of Technology Developers, Teachers and Students

    ERIC Educational Resources Information Center

    Hillman, Thomas

    2014-01-01

    This article examines mathematical activity with digital technology by tracing it from its development through its use in classrooms. Drawing on material-semiotic approaches from the field of Science and Technology Studies, it examines the visions of mathematical activity that developers had for an advanced graphing calculator. It then follows the…

  9. Fundamentals of Cryogenics

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley; Tomsik, Thomas; Moder, Jeff

    2014-01-01

    Analysis of the extreme conditions that are encountered in cryogenic systems requires the most effort out of analysts and engineers. Due to the costs and complexity associated with the extremely cold temperatures involved, testing is sometimes minimized and extra analysis is often relied upon. This short course is designed as an introduction to cryogenic engineering and analysis, and it is intended to introduce the basic concepts related to cryogenic analysis and testing as well as help the analyst understand the impacts of various requests on a test facility. Discussion will revolve around operational functions often found in cryogenic systems, hardware for both tests and facilities, and what design or modelling tools are available for performing the analysis. Emphasis will be placed on what scenarios to use what hardware or the analysis tools to get the desired results. The class will provide a review of first principles, engineering practices, and those relations directly applicable to this subject including such topics as cryogenic fluids, thermodynamics and heat transfer, material properties at low temperature, insulation, cryogenic equipment, instrumentation, refrigeration, testing of cryogenic systems, cryogenics safety and typical thermal and fluid analysis used by the engineer. The class will provide references for further learning on various topics in cryogenics for those who want to dive deeper into the subject or have encountered specific problems.

  10. Noble metal nanoparticles embedding into polymeric materials: From fundamentals to applications.

    PubMed

    Prakash, Jai; Pivin, J C; Swart, H C

    2015-12-01

    This review covers some key concepts related to embedding of the noble metal nanoparticles in polymer surfaces. The metal nanoparticles embedded into the polymer matrix can provide high-performance novel materials that find applications in modern nanotechnology. In particular, the origin of various processes that drive the embedding phenomenon, growth of the nanostructure at the surface, factors affecting the embedding including role of surface, interface energies and thermodynamic driving forces with emphasis on the fundamental and technological applications, under different conditions (annealing and ion beams) have been discussed. In addition to the conventional thermal process for embedding which includes the measure of fundamental polymer surface properties with relevant probing techniques, this review discusses the recent advances carried out in the understanding of embedding phenomenon starting from thin metal films to growth of the nanoparticles and embedded nanostructures using novel ion beam techniques. PMID:26584861

  11. Efficient visible driven photocatalyst, silver phosphate: performance, understanding and perspective.

    PubMed

    Martin, David James; Liu, Guigao; Moniz, Savio J A; Bi, Yingpu; Beale, Andrew M; Ye, Jinhua; Tang, Junwang

    2015-11-01

    Photocatalysis is a promising technology that can contribute to renewable energy production from water and water purification. In order to further develop the field and meet industrial requirements, it is imperative to focus on advancing high efficiency visible light photocatalysts, such as silver phosphate (Ag3PO4). This review aims to highlight the recent progress made in the field, focusing on oxygen production from water, and organic contaminant decomposition using Ag3PO4. The most important advances are discussed and explained in detail, including semiconductor-semiconductor junctions, metal-semiconductor junctions, exposing facet control, and fundamental understanding using advanced spectroscopies and computational chemistry. The review then concludes by critically summarising both findings and current perspectives, and ultimately how the field might best advance in the near future. PMID:26204436

  12. DOE Fundamentals Handbook: Instrumentation and Control, Volume 1

    SciTech Connect

    Not Available

    1992-06-01

    The Instrumentation and Control Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of instrumentation and control systems. The handbook includes information on temperature, pressure, flow, and level detection systems; position indication systems; process control systems; and radiation detection principles. This information will provide personnel with an understanding of the basic operation of various types of DOE nuclear facility instrumentation and control systems.

  13. Understanding the views of those who care for patients with cancer on advance care planning and end-of-life care.

    PubMed

    Mattes, Malcolm D; Tung, Kaity; Baum, Rachel; Parikh, Kapila; Ashamalla, Hani

    2015-12-01

    An electronic survey was used to assess the views of a diverse nationwide cohort of health care professionals regarding advance care planning and end-of-life care. A total of 645 responses were received. If diagnosed with a serious incurable illness with limited life expectancy, 97% would want to discuss their prognosis, 74% would refuse cardiopulmonary resuscitation, and 72% favored supportive/comfort care to more aggressive life-prolonging treatments. However, prognosis was thought to be discussed with only 52% of such patients, and just 5% thought doctors were either very or extremely successful at explaining advanced life-sustaining treatments to patients. Greater than 90% believed these discussions should best occur when a patient is thought to have one or more years to live and 80% thought they are best initiated in the outpatient setting. PMID:24939206

  14. How mesoscale lasers can answer fundamental questions related to nanolasers

    NASA Astrophysics Data System (ADS)

    Wang, T.; Puccioni, G. P.; Lippi, G. L.

    2016-04-01

    Nanolasers have steadily gained interest in the past years thanks to considerable technological advances. Interest in very small lasers dates back to the early 1980's and considerable effort was placed throughout the 1990's on understanding the threshold and coherence properties of the so-called thresholdless laser. Little progress has been made on this front, mostly due to the scant amount of information coming from experiments, limited by the current detection technology. Very small-sized lasers, thanks to their extremely reduced cavity (and active medium) volumes, offer very low thresholds, but also an accompanying exiguous photon flux, which renders detection extremely challenging. Coupled to very fast internal constants, this requirement renders most kinds of measurements currently impossible: only statistical information, based on photon counting, has been gathered from nanolasers. The problem is aggravated from a fundamental understanding viewpoint, by the fact that most of these devices are optically pumped - i.e., they suffer from poor stability and reproducibility in operating parameters - and emit very short light pulses. This paper gives a brief overview of these problems and discusses the potential for using somewhat larger devices (mesolasers), for which full detection capabilities (barely) exist. As shown with the help of a new modeling approach compared to experimental results, lasers in the mesoscale display emerging properties which can be expected to exist in nanolasers, but are unknown at the macroscopic scale.

  15. Early Understanding of Equality

    ERIC Educational Resources Information Center

    Leavy, Aisling; Hourigan, Mairéad; McMahon, Áine

    2013-01-01

    Quite a bit of the arithmetic in elementary school contains elements of algebraic reasoning. After researching and testing a number of instructional strategies with Irish third graders, these authors found effective methods for cultivating a relational concept of equality in third-grade students. Understanding equality is fundamental to algebraic…

  16. Fundamentals of ICF Hohlraums

    SciTech Connect

    Rosen, M D

    2005-09-30

    On the Nova Laser at LLNL, we demonstrated many of the key elements required for assuring that the next laser, the National Ignition Facility (NIF) will drive an Inertial Confinement Fusion (ICF) target to ignition. The indirect drive (sometimes referred to as ''radiation drive'') approach converts laser light to x-rays inside a gold cylinder, which then acts as an x-ray ''oven'' (called a hohlraum) to drive the fusion capsule in its center. On Nova we've demonstrated good understanding of the temperatures reached in hohlraums and of the ways to control the uniformity with which the x-rays drive the spherical fusion capsules. In these lectures we will be reviewing the physics of these laser heated hohlraums, recent attempts at optimizing their performance, and then return to the ICF problem in particular to discuss scaling of ICF gain with scale size, and to compare indirect vs. direct drive gains. In ICF, spherical capsules containing Deuterium and Tritium (DT)--the heavy isotopes of hydrogen--are imploded, creating conditions of high temperature and density similar to those in the cores of stars required for initiating the fusion reaction. When DT fuses an alpha particle (the nucleus of a helium atom) and a neutron are created releasing large amount amounts of energy. If the surrounding fuel is sufficiently dense, the alpha particles are stopped and can heat it, allowing a self-sustaining fusion burn to propagate radially outward and a high gain fusion micro-explosion ensues. To create those conditions the outer surface of the capsule is heated (either directly by a laser or indirectly by laser produced x-rays) to cause rapid ablation and outward expansion of the capsule material. A rocket-like reaction to that outward flowing heated material leads to an inward implosion of the remaining part of the capsule shell. The pressure generated on the outside of the capsule can reach nearly 100 megabar (100 million times atmospheric pressure [1b = 10{sup 6} cgs

  17. Fundamentals of Digital Engineering: Designing for Reliability

    NASA Technical Reports Server (NTRS)

    Katz, R.; Day, John H. (Technical Monitor)

    2001-01-01

    The concept of designing for reliability will be introduced along with a brief overview of reliability, redundancy and traditional methods of fault tolerance is presented, as applied to current logic devices. The fundamentals of advanced circuit design and analysis techniques will be the primary focus. The introduction will cover the definitions of key device parameters and how analysis is used to prove circuit correctness. Basic design techniques such as synchronous vs asynchronous design, metastable state resolution time/arbiter design, and finite state machine structure/implementation will be reviewed. Advanced topics will be explored such as skew-tolerant circuit design, the use of triple-modular redundancy and circuit hazards, device transients and preventative circuit design, lock-up states in finite state machines generated by logic synthesizers, device transient characteristics, radiation mitigation techniques. worst-case analysis, the use of timing analyzer and simulators, and others. Case studies and lessons learned from spaceflight designs will be given as examples

  18. An Historical Perspective on How Advances in Microscopic Imaging Contributed to Understanding the Leishmania Spp. and Trypanosoma cruzi Host-Parasite Relationship

    PubMed Central

    Florentino, P. T. V.; Real, F.; Bonfim-Melo, A.; Orikaza, C. M.; Ferreira, E. R.; Pessoa, C. C.; Lima, B. R.; Sasso, G. R. S.; Mortara, R. A.

    2014-01-01

    The literature has identified complex aspects of intracellular host-parasite relationships, which require systematic, nonreductionist approaches and spatial/temporal information. Increasing and integrating temporal and spatial dimensions in host cell imaging have contributed to elucidating several conceptual gaps in the biology of intracellular parasites. To access and investigate complex and emergent dynamic events, it is mandatory to follow them in the context of living cells and organs, constructing scientific images with integrated high quality spatiotemporal data. This review discusses examples of how advances in microscopy have challenged established conceptual models of the intracellular life cycles of Leishmania spp. and Trypanosoma cruzi protozoan parasites. PMID:24877115

  19. Magnetic Reconnection: A Fundamental Process in Space Plasmas

    NASA Technical Reports Server (NTRS)

    Hesse, Michael

    2010-01-01

    For many years, collisionless magnetic reconnect ion has been recognized as a fundamental process, which facilitates plasma transport and energy release in systems ranging from the astrophysical plasmas to magnetospheres and even laboratory plasma. Beginning with work addressing solar dynamics, it has been understood that reconnection is essential to explain solar eruptions, the interaction of the solar wind with the magnetosphere, and the dynamics of the magnetosphere. Accordingly, the process of magnetic reconnection has been and remains a prime target for space-based and laboratory studies, as well as for theoretical research. Much progress has been made throughout the years, beginning with indirect verifications by studies of processes enabled by reconnection, such as Coronal Mass Ejections, Flux Transfer Events, and Plasmoids. Theoretical advances have accompanied these observations, moving knowledge beyond the Sweet-Parker theory to the recognition that other, collisionless, effects are available and likely to support much faster reconnect ion rates. At the present time we are therefore near a break-through in our understanding of how collisionless reconnect ion works. Theory and modeling have advanced to the point that two competing theories are considered leading candidates for explaining the microphysics of this process. Both theories predict very small spatial and temporal scales. which are. to date, inaccessible to space-based or laboratory measurements. The need to understand magnetic reconnect ion has led NASA to begin the implementation of a tailored mission, Magnetospheric MultiScale (MMS), a four spacecraft cluster equipped to resolve all relevant spatial and temporal scales. In this presentation, we present an overview of current knowledge as well as an outlook towards measurements provided by MMS.

  20. Understanding development and ripening of fruit crops in an ‘omics’ era

    PubMed Central

    Gapper, Nigel E; Giovannoni, James J; Watkins, Christopher B

    2014-01-01

    Next generation sequencing has revolutionized plant biology. Not only has our understanding of plant metabolism advanced using model systems and modern chromatography, but application of ‘omics’-based technology has been widely extended to non-model systems as costs have plummeted and efficiency increased. As a result, important fundamental questions relating to important horticultural crops are being answered, and novel approaches with application to industry are in progress. Here we review recent research advances on development and ripening of fruit crops, how next generation sequencing approaches are driving this advance and the emerging future landscape. PMID:26504543

  1. Multiphase flow and phase change in microgravity: Fundamental research and strategic research for exploration of space

    NASA Technical Reports Server (NTRS)

    Singh, Bhim S.

    2003-01-01

    NASA is preparing to undertake science-driven exploration missions. The NASA Exploration Team's vision is a cascade of stepping stones. The stepping-stone will build the technical capabilities needed for each step with multi-use technologies and capabilities. An Agency-wide technology investment and development program is necessary to implement the vision. The NASA Exploration Team has identified a number of areas where significant advances are needed to overcome all engineering and medical barriers to the expansion of human space exploration beyond low-Earth orbit. Closed-loop life support systems and advanced propulsion and power technologies are among the areas requiring significant advances from the current state-of-the-art. Studies conducted by the National Academy of Science's National Research Council and Workshops organized by NASA have shown that multiphase flow and phase change play a crucial role in many of these advanced technology concepts. Lack of understanding of multiphase flow, phase change, and interfacial phenomena in the microgravity environment has been a major hurdle. An understanding of multiphase flow and phase change in microgravity is, therefore, critical to advancing many technologies needed. Recognizing this, the Office of Biological and Physical Research (OBPR) has initiated a strategic research thrust to augment the ongoing fundamental research in fluid physics and transport phenomena discipline with research especially aimed at understanding key multiphase flow related issues in propulsion, power, thermal control, and closed-loop advanced life support systems. A plan for integrated theoretical and experimental research that has the highest probability of providing data, predictive tools, and models needed by the systems developers to incorporate highly promising multiphase-based technologies is currently in preparation. This plan is being developed with inputs from scientific community, NASA mission planners and industry personnel

  2. Understanding individual routing behaviour.

    PubMed

    Lima, Antonio; Stanojevic, Rade; Papagiannaki, Dina; Rodriguez, Pablo; González, Marta C

    2016-03-01

    Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779-782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65-100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325-362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin-destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions. PMID:26962031

  3. Space fundamentals for the war fighter

    NASA Astrophysics Data System (ADS)

    Clapp, William G.

    1994-02-01

    The quickening space technology revolution is as natural as life itself. Technology leads us to believe that anything is possible and that we are all privileged users. An understanding of some of the limitations of our space assets should moderate our expectations. The purpose of this paper is to provide a short and concise overview of the space environment and a fundamental understanding of space assets in order to understand their capabilities. The paper has been limited to the basic concepts of the atmosphere, rocket propulsion, launch vehicles, communications spectrum, and satellite assets. With the demise of the USSR threat, also gone are sufficient budgets that were going to provide the next generation of bigger and better satellites. We must accept the fact that next generation satellite security systems under development are now too expensive to field. Next generation satellite system funding may someday come again when a new threat diminishes our technological advantage.

  4. Ablative Thermal Protection System Fundamentals

    NASA Technical Reports Server (NTRS)

    Beck, Robin A. S.

    2013-01-01

    This is the presentation for a short course on the fundamentals of ablative thermal protection systems. It covers the definition of ablation, description of ablative materials, how they work, how to analyze them and how to model them.

  5. Fundamental mechanisms of micromachine reliability

    SciTech Connect

    DE BOER,MAARTEN P.; SNIEGOWSKI,JEFFRY J.; KNAPP,JAMES A.; REDMOND,JAMES M.; MICHALSKE,TERRY A.; MAYER,THOMAS K.

    2000-01-01

    RH up to a threshold value, depending on the coating chemistry. The mechanism for the adhesion increase beyond this threshold value is that the coupling agent reconfigures from a surface to a bulk phase (Chapter 3). To investigate the details of how the adhesion increase occurs, the authors developed the mechanics for adhesion hysteresis measurements. These revealed that near-crack tip compression is the underlying cause of the adhesion increase (Chapter 4). A vacuum deposition chamber for silane coupling agent deposition was constructed. Results indicate that vapor deposited coatings are less susceptible to degradation at high RH (Chapter 5). To address issues relating to surfaces in relative motion, a new test structure to measure friction was developed. In contrast to other surface micromachined friction test structures, uniform apparent pressure is applied in the frictional contact zone (Chapter 6). The test structure will enable friction studies over a large pressure and dynamic range. In this LDRD project, the authors established an infrastructure for MEMS adhesion and friction metrology. They then characterized in detail the performance of hydrophilic and hydrophobic films under humid conditions, and determined mechanisms which limit this performance. These studies contribute to a fundamental understanding for MEMS reliability design rules. They also provide valuable data for MEMS packaging requirements.

  6. BOOK REVIEWS: Quantum Mechanics: Fundamentals

    NASA Astrophysics Data System (ADS)

    Whitaker, A.

    2004-02-01

    mechanics, which is assumed, but to examine whether it gives a consistent account of measurement. The conclusion is that after a measurement, interference terms are ‘effectively’ absent; the set of ‘one-to-one correlations between states of the apparatus and the object’ has the same form as that of everyday statistics and is thus a probability distribution. This probability distribution refers to potentialities, only one of which is actually realized in any one trial. Opinions may differ on whether their treatment is any less vulnerable to criticisms such as those of Bell. To sum up, Gottfried and Yan’s book contains a vast amount of knowledge and understanding. As well as explaining the way in which quantum theory works, it attempts to illuminate fundamental aspects of the theory. A typical example is the ‘fable’ elaborated in Gottfried’s article in Nature cited above, that if Newton were shown Maxwell’s equations and the Lorentz force law, he could deduce the meaning of E and B, but if Maxwell were shown Schrödinger’s equation, he could not deduce the meaning of Psi. For use with a well-constructed course (and, of course, this is the avowed purpose of the book; a useful range of problems is provided for each chapter), or for the relative expert getting to grips with particular aspects of the subject or aiming for a deeper understanding, the book is certainly ideal. It might be suggested, though, that, even compared to the first edition, the isolated learner might find the wide range of topics, and the very large number of mathematical and conceptual techniques, introduced in necessarily limited space, somewhat overwhelming. The second book under consideration, that of Schwabl, contains ‘Advanced’ elements of quantum theory; it is designed for a course following on from one for which Gottfried and Yan, or Schwabl’s own `Quantum Mechanics' might be recommended. It is the second edition in English, and is a translation of the third German edition

  7. Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Chambliss, Joe

    2004-01-01

    Viewgraphs on Advanced Life Support (ALS) Systems are presented. The topics include: 1) Fundamental Need for Advanced Life Support; 2) ALS organization; 3) Requirements and Rationale; 4) Past Integrated tests; 5) The need for improvements in life support systems; 6) ALS approach to meet exploration goals; 7) ALS Projects showing promise to meet exploration goals; and 9) GRC involvement in ALS.

  8. Soil hydrology: Recent methodological advances, challenges, and perspectives

    NASA Astrophysics Data System (ADS)

    Vereecken, H.; Huisman, J. A.; Hendricks Franssen, H. J.; Brüggemann, N.; Bogena, H. R.; Kollet, S.; Javaux, M.; van der Kruk, J.; Vanderborght, J.

    2015-04-01

    Technological and methodological progress is essential to improve our understanding of fundamental processes in natural and engineering sciences. In this paper, we will address the potential of new technological and methodological advancements in soil hydrology to move forward our understanding of soil water related processes across a broad range of scales. We will focus on advancements made in quantifying root water uptake processes, subsurface lateral flow, and deep drainage at the field and catchment scale, respectively. We will elaborate on the value of establishing a science-driven network of hydrological observatories to test fundamental hypotheses, to study organizational principles of soil hydrologic processes at catchment scale, and to provide data for the development and validation of models. Finally, we discuss recent developments in data assimilation methods, which provide new opportunities to better integrate observations and models and to improve predictions of the short-term evolution of hydrological processes.

  9. Advances in Soil Biology: What does this mean for assessing soil change?

    NASA Astrophysics Data System (ADS)

    Black, Helaina; Mele, Pauline

    2015-07-01

    Our interests in soil change are moving away from soil properties and increasingly towards changes in the processes and functioning of soils. Soil organisms are fundamental to dynamics and change in soils through their fundamental role in soil processes [1]. However it is only with recent technical and theoretical advances that we have started to establish quantitative relationships between soil biology and soil change (c.f. [2]). It is this predictive understanding that will enable us to fully integrate soil biology into the effective monitoring and sustainable management of soils. This paper outlines some of the recent advances in soil biology and discusses their relevance to monitoring and management.

  10. Understanding the nano- and macromechanical behaviour, the failure and fatigue mechanisms of advanced and natural polymer fibres by Raman/IR microspectrometry

    NASA Astrophysics Data System (ADS)

    Colomban, Philippe

    2013-03-01

    The coupled mechanical and Raman/infrared (IR) analysis of the (nano)structure and texture of synthetic and natural polymer fibres (polyamides (PA66), polyethylene terephthalate (PET), polypropylene (PP), poly(paraphenylene benzobisoxazole) (PBO), keratin/hair, Bombyx mori, Gonometa rufobrunea/postica Antheraea/Tussah silkworms and Nephila Madagascarensis spider silks) is applied so as to differentiate between crystalline and amorphous macromolecules. Bonding is very similar in the two cases but a broader distribution of conformations is observed for the amorphous macromolecules. These conclusions are then used to discuss the modifications induced by the application of a tensile or compressive stress, including the effects of fatigue. Detailed attention is paid to water and the inter-chain coupling for which the importance of hydrogen bonding is reconsidered. The significant role of the ‘amorphous’ bonds/domains in the process of fracture/fatigue is shown. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN2012, 30 October-2 November 2012, Ha Long, Vietnam.

  11. Fifth Joint Meeting of J-CaP and CaPSURE: advancing the global understanding of prostate cancer and its management.

    PubMed

    Akaza, Hideyuki; Carroll, Peter; Cooperberg, Matthew R; Hinotsu, Shiro

    2012-03-01

    This report summarizes the presentations and discussions that took place at the Fifth Joint Meeting of J-CaP and CaPSURE held in Tokyo, Japan, in July 2011. The J-CaP and CaPSURE Joint Initiative was established in 2007 with the objective of analyzing, reviewing, comparing and contrasting data on prostate cancer patients from Japan and the USA within the two important large-scale, longitudinal, observational databases-J-CaP and CaPSURE. Since its inception, the initiative has reviewed a wide range of topics and generated valuable data on the patterns of prostate cancer treatment and patient outcomes in the two geographical regions. The objectives of this 5th Joint Meeting were to provide an update on the current status of the J-CaP and CaPSURE databases, and also to discuss perspectives from a range of other Asian countries-Japan, China, Indonesia and Korea-on the use of androgen deprivation therapy for prostate cancer. The collaborators recognize that large databases, such as J-CaP and CaPSURE, provide valuable 'real-world' information, to complement data from clinical trials, which can help to advance the clinical management of prostate cancer patients worldwide. It is anticipated that in the near future, the Joint Initiative will expand globally to include patient registries from other countries so that best practice can be shared and regional differences in patients, treatments and outcomes can be explored. PMID:22217576

  12. Fundamental Structure of Matter and Strong Interaction

    SciTech Connect

    Jian-Ping Chen

    2011-11-01

    More than 99% of the visible matter in the universe are the protons and neutrons. Their internal structure is mostly governed by the strong interaction. Understanding their internal structure in terms of fundamental degrees-of-freedom is one of the most important subjects in modern physics. Worldwide efforts in the last few decades have lead to numerous surprises and discoveries, but major challenges still remain. An overview of the progress will be presented with a focus on the recent studies of the proton and neutron's electromagnetic and spin structure. Future perspectives will be discussed.

  13. Fundamental investigation of duct/ESP phenomena

    SciTech Connect

    Brown, C.A. ); Durham, M.D. ); Sowa, W.A. . Combustion Lab.); Himes, R.M. ); Mahaffey, W.A. )

    1991-10-21

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  14. Fundamental science of nanometer-size clusters

    SciTech Connect

    Wilcoxon, J.P.; Newcomer, P.P.; Samara, G.A.; Venturini, E.L.; Williamson, R.L.

    1995-10-01

    This research has produced a variety of monodisperse, nanometer-size clusters (nanoclusters for short), characterized their size and crystal structure and developed a scientific understanding of the size dependence of their physical properties. Of specific interest were the influence of quantum electronic confinement on the optical properties, magnetic properties, and dielectric properties. These properties were chosen both for their potential practical impact on various applications identified in the National Critical Technologies list (e.g., catalysis, information storage, sensors, environmental remediation, ...) as well as for their importance to the fundamental science of clusters. An Executive Summary provides a description of the major highlights.

  15. A Study of the Abundance and 13C/12C Ratio of Atmospheric Carbon Dioxide to Advance the Scientific Understanding of Terrestrial Processes Regulating the Global Carbon Cycle

    SciTech Connect

    Stephen C. Piper

    2005-10-15

    The primary goal of our research program, consistent with the goals of the U.S. Climate Change Science Program and funded by the terrestrial carbon processes (TCP) program of DOE, has been to improve understanding of changes in the distribution and cycling of carbon among the active land, ocean and atmosphere reservoirs, with particular emphasis on terrestrial ecosystems. Our approach is to systematically measure atmospheric CO2 to produce time series data essential to reveal temporal and spatial patterns. Additional measurements of the 13C/12C isotopic ratio of CO2 provide a basis for distinguishing organic and inorganic processes. To pursue the significance of these patterns further, our research also involved interpretations of the observations by models, measurements of inorganic carbon in sea water, and of CO2 in air near growing land plants.

  16. Understanding the fate and biological effects of Ag- and TiO₂-nanoparticles in the environment: The quest for advanced analytics and interdisciplinary concepts.

    PubMed

    Schaumann, Gabriele E; Philippe, Allan; Bundschuh, Mirco; Metreveli, George; Klitzke, Sondra; Rakcheev, Denis; Grün, Alexandra; Kumahor, Samuel K; Kühn, Melanie; Baumann, Thomas; Lang, Friederike; Manz, Werner; Schulz, Ralf; Vogel, Hans-Jörg

    2015-12-01

    Engineered inorganic nanoparticles (EINP) from consumers' products and industrial applications, especially silver and titanium dioxide nanoparticles (NP), are emitted into the aquatic and terrestrial environments in increasing amounts. However, the current knowledge on their environmental fate and biological effects is diverse and renders reliable predictions complicated. This review critically evaluates existing knowledge on colloidal aging mechanisms, biological functioning and transport of Ag NP and TiO2 NP in water and soil and it discusses challenges for concepts, experimental approaches and analytical methods in order to obtain a comprehensive understanding of the processes linking NP fate and effects. Ag NP undergo dissolution and oxidation with Ag2S as a thermodynamically determined endpoint. Nonetheless, Ag NP also undergo colloidal transformations in the nanoparticulate state and may act as carriers for other substances. Ag NP and TiO2 NP can have adverse biological effects on organisms. Whereas Ag NP reveal higher colloidal stability and mobility, the efficiency of NOM as a stabilizing agent is greater towards TiO2 NP than towards Ag NP, and multivalent cations can dominate the colloidal behavior over NOM. Many of the past analytical obstacles have been overcome just recently. Single particle ICP-MS based methods in combination with field flow fractionation techniques and hydrodynamic chromatography have the potential to fill the gaps currently hampering a comprehensive understanding of fate and effects also at a low field relevant concentrations. These analytical developments will allow for mechanistically orientated research and transfer to a larger set of EINP. This includes separating processes driven by NP specific properties and bulk chemical properties, categorization of effect-triggering pathways directing the EINP effects towards specific recipients, and identification of dominant environmental parameters triggering fate and effect of EINP in

  17. Recent advances in developing small molecules targeting RNA.

    PubMed

    Guan, Lirui; Disney, Matthew D

    2012-01-20

    RNAs are underexploited targets for small molecule drugs or chemical probes of function. This may be due, in part, to a fundamental lack of understanding of the types of small molecules that bind RNA specifically and the types of RNA motifs that specifically bind small molecules. In this review, we describe recent advances in the development and design of small molecules that bind to RNA and modulate function that aim to fill this void. PMID:22185671

  18. Understanding aging.

    PubMed

    Strehler, B L

    2000-01-01

    Enormous advances in our understanding of human aging have occurred during the last 50 yr. From the late 19th to the mid-20th centuries only four comprehensive and important sources of information were available: 1. August Weismann's book entitled Essays on Heredity and Kindred Biological Problems (the first of these essays dealt with The Duration of Life; 1). Weissmann states (p. 10) "In the first place in regulating the length of life, the advantage to the species, and not to the individual, is alone of any importance. This must be obvious to any one who has once thoroughly thought out the process of natural selection_". 2. A highly systematized second early source of information on aging was the collection of essays edited by Cowdry and published in 1938. This 900+ page volume contains 34 chapters and was appropriately called Problems of Aging. 3. At about the same time Raymond Pearl published his book on aging (2). Pearl believed that aging was the indirect result of cell specialization and that only the germ line was resistant to aging. Unfortunately Pearl died in the late 1930s and is largely remembered now for having been the founding editor of Quarterly Review of Biology while he was at the Johns Hopkins University, this author's alma mater. 4. Alexis Carrel wrote a monumental scientific and philosophical book, Man, the Unknown (3). Carrel believed that he had demonstrated that vertebrate cells could be kept in culture and live indefinitely, a conclusion challenged by others (more on this later). PMID:22351262

  19. Advanced Vadose Zone Simulations Using TOUGH

    SciTech Connect

    Finsterle, S.; Doughty, C.; Kowalsky, M.B.; Moridis, G.J.; Pan,L.; Xu, T.; Zhang, Y.; Pruess, K.

    2007-02-01

    The vadose zone can be characterized as a complex subsurfacesystem in which intricate physical and biogeochemical processes occur inresponse to a variety of natural forcings and human activities. Thismakes it difficult to describe, understand, and predict the behavior ofthis specific subsurface system. The TOUGH nonisothermal multiphase flowsimulators are well-suited to perform advanced vadose zone studies. Theconceptual models underlying the TOUGH simulators are capable ofrepresenting features specific to the vadose zone, and of addressing avariety of coupled phenomena. Moreover, the simulators are integratedinto software tools that enable advanced data analysis, optimization, andsystem-level modeling. We discuss fundamental and computationalchallenges in simulating vadose zone processes, review recent advances inmodeling such systems, and demonstrate some capabilities of the TOUGHsuite of codes using illustrative examples.

  20. Fundamental Processes in Plasmas. Final report

    SciTech Connect

    O'Neil, Thomas M.; Driscoll, C. Fred

    2009-11-30

    This research focuses on fundamental processes in plasmas, and emphasizes problems for which precise experimental tests of theory can be obtained. Experiments are performed on non-neutral plasmas, utilizing three electron traps and one ion trap with a broad range of operating regimes and diagnostics. Theory is focused on fundamental plasma and fluid processes underlying collisional transport and fluid turbulence, using both analytic techniques and medium-scale numerical simulations. The simplicity of these systems allows a depth of understanding and a precision of comparison between theory and experiment which is rarely possible for neutral plasmas in complex geometry. The recent work has focused on three areas in basic plasma physics. First, experiments and theory have probed fundamental characteristics of plasma waves: from the low-amplitude thermal regime, to inviscid damping and fluid echoes, to cold fluid waves in cryogenic ion plasmas. Second, the wide-ranging effects of dissipative separatrices have been studied experimentally and theoretically, finding novel wave damping and coupling effects and important plasma transport effects. Finally, correlated systems have been investigated experimentally and theoretically: UCSD experients have now measured the Salpeter correlation enhancement, and theory work has characterized the 'guiding center atoms of antihydrogen created at CERN.

  1. Advanced Laser Processing of Materials--Fundamentals and Applications

    NASA Technical Reports Server (NTRS)

    Jacobsohn, E.; Ryan, M.

    1995-01-01

    Preparation of amorphous thin films in semiconductors and their transition to the crystalline phase may apply to switching devices. Surfaces of single crystal samples of bulk In2Se3 and thin films of InSe were treated using an excimer laser, and microscopic examination showed the treated portions of the surface had become amorphous. Film samples of InSe were laser-treated like the bulk samples. Examination of these treated flims showed shifts in the optical transmittance spectra as well as surface morphology changes.

  2. Fundamentals of Marketing Core Curriculum. Test Items and Assessment Techniques.

    ERIC Educational Resources Information Center

    Smith, Clifton L.; And Others

    This document contains multiple choice test items and assessment techniques for Missouri's fundamentals of marketing core curriculum. The core curriculum is divided into these nine occupational duties: (1) communications in marketing; (2) economics and marketing; (3) employment and advancement; (4) human relations in marketing; (5) marketing…

  3. Advances in understanding the cyanobacterial CO2-concentrating-mechanism (CCM): functional components, Ci transporters, diversity, genetic regulation and prospects for engineering into plants.

    PubMed

    Price, G Dean; Badger, Murray R; Woodger, Fiona J; Long, Ben M

    2008-01-01

    Cyanobacteria have evolved a significant environmental adaptation, known as a CO(2)-concentrating-mechanism (CCM), that vastly improves photosynthetic performance and survival under limiting CO(2) concentrations. The CCM functions to transport and accumulate inorganic carbon actively (Ci; HCO(3)(-), and CO(2)) within the cell where the Ci pool is utilized to provide elevated CO(2) concentrations around the primary CO(2)-fixing enzyme, ribulose bisphosphate carboxylase-oxygenase (Rubisco). In cyanobacteria, Rubisco is encapsulated in unique micro-compartments known as carboxysomes. Cyanobacteria can possess up to five distinct transport systems for Ci uptake. Through database analysis of some 33 complete genomic DNA sequences for cyanobacteria it is evident that considerable diversity exists in the composition of transporters employed, although in many species this diversity is yet to be confirmed by comparative phenomics. In addition, two types of carboxysomes are known within the cyanobacteria that have apparently arisen by parallel evolution, and considerable progress has been made towards understanding the proteins responsible for carboxysome assembly and function. Progress has also been made towards identifying the primary signal for the induction of the subset of CCM genes known as CO(2)-responsive genes, and transcriptional regulators CcmR and CmpR have been shown to regulate these genes. Finally, some prospects for introducing cyanobacterial CCM components into higher plants are considered, with the objective of engineering plants that make more efficient use of water and nitrogen. PMID:17578868

  4. From unresponsive wakefulness to minimally conscious PLUS and functional locked-in syndromes: recent advances in our understanding of disorders of consciousness.

    PubMed

    Bruno, Marie-Aurélie; Vanhaudenhuyse, Audrey; Thibaut, Aurore; Moonen, Gustave; Laureys, Steven

    2011-07-01

    Functional neuroimaging and electrophysiology studies are changing our understanding of patients with coma and related states. Some severely brain damaged patients may show residual cortical processing in the absence of behavioural signs of consciousness. Given these new findings, the diagnostic errors and their potential effects on treatment as well as concerns regarding the negative associations intrinsic to the term vegetative state, the European Task Force on Disorders of Consciousness has recently proposed the more neutral and descriptive term unresponsive wakefulness syndrome. When vegetative/unresponsive patients show minimal signs of consciousness but are unable to reliably communicate the term minimally responsive or minimally conscious state (MCS) is used. MCS was recently subcategorized based on the complexity of patients' behaviours: MCS+ describes high-level behavioural responses (i.e., command following, intelligible verbalizations or non-functional communication) and MCS- describes low-level behavioural responses (i.e., visual pursuit, localization of noxious stimulation or contingent behaviour such as appropriate smiling or crying to emotional stimuli). Finally, patients who show non-behavioural evidence of consciousness or communication only measurable via para-clinical testing (i.e., functional MRI, positron emission tomography, EEG or evoked potentials) can be considered to be in a functional locked-in syndrome. An improved assessment of brain function in coma and related states is not only changing nosology and medical care but also offers a better-documented diagnosis and prognosis and helps to further identify the neural correlates of human consciousness. PMID:21674197

  5. Advances in speech processing

    NASA Astrophysics Data System (ADS)

    Ince, A. Nejat

    1992-10-01

    The field of speech processing is undergoing a rapid growth in terms of both performance and applications and this is fueled by the advances being made in the areas of microelectronics, computation, and algorithm design. The use of voice for civil and military communications is discussed considering advantages and disadvantages including the effects of environmental factors such as acoustic and electrical noise and interference and propagation. The structure of the existing NATO communications network and the evolving Integrated Services Digital Network (ISDN) concept are briefly reviewed to show how they meet the present and future requirements. The paper then deals with the fundamental subject of speech coding and compression. Recent advances in techniques and algorithms for speech coding now permit high quality voice reproduction at remarkably low bit rates. The subject of speech synthesis is next treated where the principle objective is to produce natural quality synthetic speech from unrestricted text input. Speech recognition where the ultimate objective is to produce a machine which would understand conversational speech with unrestricted vocabulary, from essentially any talker, is discussed. Algorithms for speech recognition can be characterized broadly as pattern recognition approaches and acoustic phonetic approaches. To date, the greatest degree of success in speech recognition has been obtained using pattern recognition paradigms. It is for this reason that the paper is concerned primarily with this technique.

  6. Diagnostic and interventional musculoskeletal ultrasound: part 1. Fundamentals.

    PubMed

    Smith, Jay; Finnoff, Jonathan T

    2009-01-01

    Musculoskeletal ultrasound involves the use of high-frequency sound waves to image soft tissues and bony structures in the body for the purposes of diagnosing pathology or guiding real-time interventional procedures. Recently, an increasing number of physicians have integrated musculoskeletal ultrasound into their practices to facilitate patient care. Technological advancements, improved portability, and reduced costs continue to drive the proliferation of ultrasound in clinical medicine. This increased interest creates a need for education pertaining to all aspects of musculoskeletal ultrasound. The primary purpose of this article is to review diagnostic ultrasound technology and its potential clinical applications in the evaluation and treatment of patients with neurologic and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared with other available imaging modalities, (2) describe how ultrasound machines produce images using sound waves, (3) discuss the steps necessary to acquire and optimize an ultrasound image, (4) understand the different ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones, and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound in musculoskeletal practice. Part 1 of this 2-part article reviews the fundamentals of clinical ultrasonographic imaging, including relevant physics, equipment, training, image optimization, and scanning principles for diagnostic and interventional purposes. PMID:19627875

  7. Fundamental Fluidization Research Project. Environmental Assessment

    SciTech Connect

    Not Available

    1994-01-01

    Morgantown Energy Technology Center proposes to conduct fundamental research on fluidization technology by designing, constructing, and operating a 2-foot diameter, 50-foot high, pressurized fluidized-bed unit. The anticipated result of the proposed project would be a better, understanding of fluidization phenomena under pressurized and high velocity conditions. This improved understanding would, provide a sound basis for design and scale-up of pressurized circulating fluidized-bed combustion (PCFBC) processes for fossil energy applications. Based on the analysis in the EA, DOE has determined that the proposed action is not a major, Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required and the Department is issuing this FONSI.

  8. The electrochemistry of carbon nanotubes: fundamentals and applications.

    PubMed

    Pumera, Martin

    2009-01-01

    Carbon nanotubes (CNTs) are in the forefront of electrochemical research. It has become clear that an understanding of the fundamental reasons for the electrochemical activity of CNTs is essential for further progress in the field. This review provides a critical discussion of the fundamental reasons behind the electrochemical and "electrocatalytic" activity of CNTs as well as on important applications of CNTs for sensing, biosensing, and energy storage systems. PMID:19360829

  9. Advanced Seismic Studies of the Endeavour Ridge: Understanding the Interplay among Magmatic, Hydrothermal, and Tectonic Processes at Mid-Ocean Ridges

    NASA Astrophysics Data System (ADS)

    Arnoux, G. M.; VanderBeek, B. P.; Morgan, J. V.; Hooft, E. E. E.; Toomey, D. R.; Wilcock, W. S. D.; Warner, M.

    2014-12-01

    At mid-ocean ridges magmatic, hydrothermal, and tectonic processes are linked. Understanding their interactions requires mapping magmatic systems and tectonic structures, as well as their relationship to hydrothermal circulation. Three-dimensional seismic images of the crust can be used to infer the size, shape, and location of magma reservoirs, in addition to the structure of the thermal boundary layer that connects magmatic and hydrothermal processes. Travel time tomography has often been used to study these processes, however, the spatial resolution of travel time tomography is limited. Three-dimensional full waveform inversion (FWI) is a state-of-the art seismic method developed for use in the oil industry to obtain high-resolution models of the velocity structure. The primary advantage of FWI is that it has the potential to resolve subsurface structures on the order of half the seismic wavelength—a significant improvement on conventional travel time tomography. Here, we apply anisotropic FWI to data collected on the Endeavour segment of the Juan de Fuca Ridge. Starting models for anisotropic P-wave velocity were obtained by travel time tomography [Weekly et al., 2014]. During FWI, the isotropic velocity model is updated and anisotropy is held constant. We have recovered low-velocity zones approximately 2-3 km beneath the ridge axis that likely correspond to a segmented magma-rich body and are in concert with those previously resolved using multi-channel seismic reflection methods. The segmented crustal magma body underlies all five known high-temperature hydrothermal vent fields along the Endeavour segment. A high-velocity zone, shallower than the observed low-velocity zones, underlies the southernmost hydrothermal vent field. This may be indicative of waning hydrothermal activity in which minerals are crystallizing beneath the vent field. Our FWI study of the Endeavour Ridge will provide the most detailed three-dimensional images of the crustal structure to

  10. The Oak Ridge Field Research Center : Advancing Scientific Understanding of the Transportation, Fate, and Remediation of Subsurface Contamination Sources and Plumes

    SciTech Connect

    David Watson

    2005-04-18

    Historical research, development, and testing of nuclear materials across this country resulted in subsurface contamination that has been identified at over 7,000 discrete sites across the U.S. Department of Energy (DOE) complex. With the end of the Cold War threat, DOE has shifted its emphasis to remediation, decommissioning, and decontamination of the immense volumes of contaminated groundwater, sediments, and structures at its sites. DOE currently is responsible for remediating 1.7 trillion gallons of contaminated groundwater, an amount equal to approximately four times the daily U.S. water consumption, and 40 million cubic meters of contaminated soil, enough to fill approximately 17 professional sports stadiums.* DOE also sponsors research intended to improve or develop remediation technologies, especially for difficult, currently intractable contaminants or conditions. The Oak Ridge FRC is representative of some difficult sites, contaminants, and conditions. Buried wastes in contact with a shallow water table have created huge reservoirs of contamination. Rainfall patterns affect the water table level seasonally and over time. Further, the hydrogeology of the area, with its fractures and karst geology, affects the movement of contaminant plumes. Plumes have migrated long distances and to surface discharge points through ill-defined preferred flowpaths created by the fractures and karst conditions. From the standpoint of technical effectiveness, remediation options are limited, especially for contaminated groundwater. Moreover, current remediation practices for the source areas, such as capping, can affect coupled processes that, in turn, may affect the movement of subsurface contaminants in unknown ways. Research conducted at the FRC or with FRC samples therefore promotes understanding of the processes that influence the transport and fate of subsurface contaminants, the effectiveness and long-term consequences of extant remediation options, and the

  11. Environmental Law: Fundamentals for Schools.

    ERIC Educational Resources Information Center

    Day, David R.

    This booklet outlines the environmental problems most likely to arise in schools. An overview provides a fundamental analysis of environmental issues rather than comprehensive analysis and advice. The text examines the concerns that surround superfund cleanups, focusing on the legal framework, and furnishes some practical pointers, such as what to…

  12. Fundamental Cycles of Cognitive Growth.

    ERIC Educational Resources Information Center

    Pegg, John

    Over recent years, various theories have arisen to explain and predict cognitive development in mathematics education. We focus on an underlying theme that recurs throughout such theories: a fundamental cycle of growth in the learning of specific concepts, which we frame within broader global theories of individual cognitive growth. Our purpose is…

  13. Fundamentals of the Slide Library.

    ERIC Educational Resources Information Center

    Boerner, Susan Zee

    This paper is an introduction to the fundamentals of the art (including architecture) slide library, with some emphasis on basic procedures of the science slide library. Information in this paper is particularly relevant to the college, university, and museum slide library. Topics addressed include: (1) history of the slide library; (2) duties of…

  14. Fundamentals of Environmental Education. Report.

    ERIC Educational Resources Information Center

    1976

    An outline of fundamental definitions, relationships, and human responsibilities related to environment provides a basis from which a variety of materials, programs, and activities can be developed. The outline can be used in elementary, secondary, higher education, or adult education programs. The framework is based on principles of the science…

  15. Fundamentals of Microelectronics Processing (VLSI).

    ERIC Educational Resources Information Center

    Takoudis, Christos G.

    1987-01-01

    Describes a 15-week course in the fundamentals of microelectronics processing in chemical engineering, which emphasizes the use of very large scale integration (VLSI). Provides a listing of the topics covered in the course outline, along with a sample of some of the final projects done by students. (TW)

  16. Brake Fundamentals. Automotive Articulation Project.

    ERIC Educational Resources Information Center

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  17. Museum Techniques in Fundamental Education.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    Some museum techniques and methods can be used in fundamental educational programs without elaborate buildings or equipment; exhibitions should be based on valid presumptions and should take into account the "common sense" beliefs of people for whom the exhibit is designed. They can be used profitably in the economic development of local cultural…

  18. Fundamentals of Welding. Teacher Edition.

    ERIC Educational Resources Information Center

    Fortney, Clarence; And Others

    These instructional materials assist teachers in improving instruction on the fundamentals of welding. The following introductory information is included: use of this publication; competency profile; instructional/task analysis; related academic and workplace skills list; tools, materials, and equipment list; and 27 references. Seven units of…

  19. Status of Fundamental Physics Program

    NASA Technical Reports Server (NTRS)

    Lee, Mark C.

    2003-01-01

    Update of the Fundamental Physics Program. JEM/EF Slip. 2 years delay. Reduced budget. Community support and advocacy led by Professor Nick Bigelow. Reprogramming led by Fred O Callaghan/JPL team. LTMPF M1 mission (DYNAMX and SUMO). PARCS. Carrier re baselined on JEM/EF.

  20. Light as a Fundamental Particle

    ERIC Educational Resources Information Center

    Weinberg, Steven

    1975-01-01

    Presents two arguments concerning the role of the photon. One states that the photon is just another particle distinguished by a particular value of charge, spin, mass, lifetime, and interaction properties. The second states that the photon plays a fundamental role with a deep relation to ultimate formulas of physics. (GS)

  1. Sequencing our way towards understanding global eukaryotic biodiversity

    PubMed Central

    Bik, Holly M.; Porazinska, Dorota L.; Creer, Simon; Caporaso, J. Gregory; Knight, Rob; Thomas, W. Kelley

    2011-01-01

    Microscopic eukaryotes are abundant, diverse, and fill critical ecological roles across every ecosystem on earth, yet there is a well-recognized gap in our understanding of their global biodiversity. Fundamental advances in DNA sequencing and bioinformatics now allow accurate en masse biodiversity assessments of microscopic eukaryotes from environmental samples. Despite a promising outlook, the field of eukaryotic marker gene surveys faces significant challenges: how to generate data that is most useful to the community, especially in the face of evolving sequencing technology and bioinformatics pipelines, and how to incorporate an expanding number of target genes. PMID:22244672

  2. BOOK REVIEW: Infrared Thermal Imaging: Fundamentals, Research and Applications Infrared Thermal Imaging: Fundamentals, Research and Applications

    NASA Astrophysics Data System (ADS)

    Planinsic, Gorazd

    2011-09-01

    Ten years ago, a book with a title like this would be interesting only to a narrow circle of specialists. Thanks to rapid advances in technology, the price of thermal imaging devices has dropped sharply, so they have, almost overnight, become accessible to a wide range of users. As the authors point out in the preface, the growth of this area has led to a paradoxical situation: now there are probably more infrared (IR) cameras sold worldwide than there are people who understand the basic physics behind them and know how to correctly interpret the colourful images that are obtained with these devices. My experience confirms this. When I started using the IR camera during lectures on the didactics of physics, I soon realized that I needed more knowledge, which I later found in this book. A wide range of potential readers and topical areas provides a good motive for writing a book such as this one, but it also represents a major challenge for authors, as compromises in the style of writing and choice of topics are required. The authors of this book have successfully achieved this, and indeed done an excellent job. This book addresses a wide range of readers, from engineers, technicians, and physics and science teachers in schools and universities, to researchers and specialists who are professionally active in the field. As technology in this area has made great progress in recent times, this book is also a valuable guide for those who opt to purchase an infrared camera. Chapters in this book could be divided into three areas: the fundamentals of IR thermal imaging and related physics (two chapters); IR imaging systems and methods (two chapters) and applications, including six chapters on pedagogical applications; IR imaging of buildings and infrastructure, industrial applications, microsystems, selected topics in research and industry, and selected applications from other fields. All chapters contain numerous colour pictures and diagrams, and a rich list of relevant

  3. Technological advances for studying human behavior

    NASA Technical Reports Server (NTRS)

    Roske-Hofstrand, Renate J.

    1990-01-01

    Technological advances for studying human behavior are noted in viewgraph form. It is asserted that performance-aiding systems are proliferating without a fundamental understanding of how they would interact with the humans who must control them. Two views of automation research, the hardware view and the human-centered view, are listed. Other viewgraphs give information on vital elements for human-centered research, a continuum of the research process, available technologies, new technologies for persistent problems, a sample research infrastructure, the need for metrics, and examples of data-link technology.

  4. Annual Report: Advanced Combustion (30 September 2012)

    SciTech Connect

    Hawk, Jeffrey; Richards, George

    2012-09-30

    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

  5. Recent Advances in Catalytic Conversion of Ethanol to Chemicals

    SciTech Connect

    Sun, Junming; Wang, Yong

    2014-04-30

    With increased availability and decreased cost, ethanol is potentially a promising platform molecule for the production of a variety of value-added chemicals. In this review, we provide a detailed summary of recent advances in catalytic conversion of ethanol to a wide range of chemicals and fuels. We particularly focus on catalyst advances and fundamental understanding of reaction mechanisms involved in ethanol steam reforming (ESR) to produce hydrogen, ethanol conversion to hydrocarbons ranging from light olefins to longer chain alkenes/alkanes and aromatics, and ethanol conversion to other oxygenates including 1-butanol, acetaldehyde, acetone, diethyl ether, and ethyl acetate.

  6. Fundamental Studies of Crystal Growth of Microporous Materials

    NASA Technical Reports Server (NTRS)

    Dutta, P.; George, M.; Ramachandran, N.; Schoeman, B.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Microporous materials are framework structures with well-defined porosity, often of molecular dimensions. Zeolites contain aluminum and silicon atoms in their framework and are the most extensively studied amongst all microporous materials. Framework structures with P, Ga, Fe, Co, Zn, B, Ti and a host of other elements have also been made. Typical synthesis of microporous materials involve mixing the framework elements (or compounds, thereof) in a basic solution, followed by aging in some cases and then heating at elevated temperatures. This process is termed hydrothermal synthesis, and involves complex chemical and physical changes. Because of a limited understanding of this process, most synthesis advancements happen by a trial and error approach. There is considerable interest in understanding the synthesis process at a molecular level with the expectation that eventually new framework structures will be built by design. The basic issues in the microporous materials crystallization process include: (1) Nature of the molecular units responsible for the crystal nuclei formation; (2) Nature of the nuclei and nucleation process; (3) Growth process of the nuclei into crystal; (4) Morphological control and size of the resulting crystal; (5) Surface structure of the resulting crystals; (6) Transformation of frameworks into other frameworks or condensed structures. The NASA-funded research described in this report focuses to varying degrees on all of the above issues and has been described in several publications. Following is the presentation of the highlights of our current research program. The report is divided into five sections: (1) Fundamental aspects of the crystal growth process; (2) Morphological and Surface properties of crystals; (3) Crystal dissolution and transformations; (4) Modeling of Crystal Growth; (5) Relevant Microgravity Experiments.

  7. Understanding Spatial Genome Organization: Methods and Insights

    PubMed Central

    Ramani, Vijay; Shendure, Jay; Duan, Zhijun

    2016-01-01

    The manner by which eukaryotic genomes are packaged into nuclei while maintaining crucial nuclear functions remains one of the fundamental mysteries in biology. Over the last ten years, we have witnessed rapid advances in both microscopic and nucleic acid-based approaches to map genome architecture, and the application of these approaches to the dissection of higher-order chromosomal structures has yielded much new information. It is becoming increasingly clear, for example, that interphase chromosomes form stable, multilevel hierarchical structures. Among them, self-associating domains like so-called topologically associating domains (TADs) appear to be building blocks for large-scale genomic organization. This review describes features of these broadly-defined hierarchical structures, insights into the mechanisms underlying their formation, our current understanding of how interactions in the nuclear space are linked to gene regulation, and important future directions for the field. PMID:26876719

  8. Fundamental neutron physics at LANSCE

    SciTech Connect

    Greene, G.

    1995-10-01

    Modern neutron sources and science share a common origin in mid-20th-century scientific investigations concerned with the study of the fundamental interactions between elementary particles. Since the time of that common origin, neutron science and the study of elementary particles have evolved into quite disparate disciplines. The neutron became recognized as a powerful tool for studying condensed matter with modern neutron sources being primarily used (and justified) as tools for neutron scattering and materials science research. The study of elementary particles has, of course, led to the development of rather different tools and is now dominated by activities performed at extremely high energies. Notwithstanding this trend, the study of fundamental interactions using neutrons has continued and remains a vigorous activity at many contemporary neutron sources. This research, like neutron scattering research, has benefited enormously by the development of modern high-flux neutron facilities. Future sources, particularly high-power spallation sources, offer exciting possibilities for continuing this research.

  9. Fundamental Scientific Problems in Magnetic Recording

    SciTech Connect

    Schulthess, T.C.; Miller, M.K.

    2007-06-27

    Magnetic data storage technology is presently leading the high tech industry in advancing device integration--doubling the storage density every 12 months. To continue these advancements and to achieve terra bit per inch squared recording densities, new approaches to store and access data will be needed in about 3-5 years. In this project, collaboration between Oak Ridge National Laboratory (ORNL), Center for Materials for Information Technology (MINT) at University of Alabama (UA), Imago Scientific Instruments, and Seagate Technologies, was undertaken to address the fundamental scientific problems confronted by the industry in meeting the upcoming challenges. The areas that were the focus of this study were to: (1) develop atom probe tomography for atomic scale imaging of magnetic heterostructures used in magnetic data storage technology; (2) develop a first principles based tools for the study of exchange bias aimed at finding new anti-ferromagnetic materials to reduce the thickness of the pinning layer in the read head; (3) develop high moment magnetic materials and tools to study magnetic switching in nanostructures aimed at developing improved writers of high anisotropy magnetic storage media.

  10. 146 Kepler-Lamost targets fundamental parameters

    NASA Astrophysics Data System (ADS)

    Wu, Yaqian

    2015-08-01

    Accurate stellar fundamental parameters with high precision are important for distinguishing stellar populationand star study.Turn-off stars are in the relatively vital stellar evolution state. Studying turn-off stars can help us to have a more comprehensive understand of the stellar physics.With the help of observation provided by Lamost project, we obtain atmospheric parameters of 146 turn-off stars from LSP3 pipeline. Combined with stellar pulsation data from Kepler, we can get asteroseismic characteristic of stars,such as Δν and νmax.In this paper,we constructed a grid of evolutionary models, with the mass range from 0.8 to 2.5 M⊙ and metallicities Zini = 0.0085, 0.0105, 0.0130, 0.0165, 0.0200, 0.0250, 0.0300, 0.0400 (i.e.[Fe/H] from -0.3 to 0.4dex).All evolutionary tracks were started in the pre-main sequence birth line and ended at the base of Red Giant Branch.Based on the stellar model grid we constructed,as well as Kepler-Lamost observations, we obtained fundamental parameters of 146 around turn-off stars, and found that 112 targets lied in turn-off state or in the Main Sequence,15 targets are subgiant stars and 7 targets have evolved to the red giants stage.Then we use pulsation code(JIG) of Guenther to extract theorical individual frequencies and calculate theorical Δν.Meanwhile we obtained more precise fundamental parameters of these stars.

  11. Understanding the Properties and Structure of Metallic Glasses at the Atomic Level

    SciTech Connect

    Egami, T.

    2010-01-01

    Liquids and glasses have been well known to human kind for millennia. And yet major mysteries remain in the behavior of glasses and liquids at the atomic level, and identifying the microscopic mechanisms that control the properties of glasses is one of the most challenging unsolved problems in physical sciences. For this reason, applying simplistic approaches to explain the behavior of metallic glasses can lead to serious errors. On the other hand because metallic glasses are atomic glasses with relatively simple structure, they may offer better opportunities to advance our fundamental understanding on the nature of the glass. The difficulties inherent to the problem and some recent advances are reviewed here.

  12. Instead of Erklären and Verstehen: William James on Human Understanding

    NASA Astrophysics Data System (ADS)

    Leary, David E.

    Perhaps more than any other American psychologist and philosopher, William James (1842-1910) was intimately familiar with contemporary European thought and debate, including the discussion of Erklären and Verstehen advanced by Wilhelm Dilthey (1833-1911) and others around the turn of the twentieth century. Even before this discussion was initiated, James had been dealing with related issues, pondering alternative solutions, and formulating his own original views on human understanding. These views coalesced in a distinctive approach to cognition. Fundamental to this approach was a belief in possibility and probability as innate features of the physical as well as mental manifestations of the universe. Also fundamental was a conviction that understanding is understanding, regardless of its viewpoint, object, or label as either "descriptive" or "explanatory."

  13. Advances in the understanding of cancer immunotherapy.

    PubMed

    Shore, Neal D

    2015-09-01

    The principal role of the immune system is to prevent and eradicate pathogens and infections. The key characteristics or features of an effective immune response include specificity, trafficking, antigen spread and durability (memory). The immune system is recognised to have a critical role in controlling cancer through a dynamic relationship with tumour cells. Normally, at the early stages of tumour development, the immune system is capable of eliminating tumour cells or keeping tumour growth abated; however, tumour cells may evolve multiple pathways over time to evade immune control. Immunotherapy may be viewed as a treatment designed to boost or restore the ability of the immune system to fight cancer, infections and other diseases. Immunotherapy manifests differently from traditional cancer treatments, eliciting delayed response kinetics and thus may be more effective in patients with lower tumour burden, in whom disease progression may be less rapid, thereby allowing ample time for the immunotherapy to evolve. Because immunotherapies may have a different mechanism of action from traditional cytotoxic or targeted biological agents, immunotherapy techniques have the potential to combine synergistically with traditional therapies. PMID:24612369

  14. Recent advances in understanding Colombian mangroves

    NASA Astrophysics Data System (ADS)

    Polanía, J.; Urrego, L. E.; Agudelo, C. M.

    2015-02-01

    Throughout the last 15 years, researchers at the National University of Colombia at Medellin have studied Colombian mangroves. Remote sensing, pollen analysis of superficial and deep sediments, Holocene coastal vegetation dynamics, sediment dating using 14C and 210Pb, sampling in temporary plots, sampling in temporary and permanent plots, and other techniques have been applied to elucidate long- and short-term mangrove community dynamics. The studied root fouling community is structured by several regulatory mechanisms; habitat heterogeneity increases species richness and abundance. Fringe mangroves were related to Ca concentration in the soil and the increased dominance of Laguncularia racemosa and other nonmangrove tree species, while the riverine mangroves were associated with Mg concentration and the dominance of Rhizophora mangle. The seedling and mangrove tree distributions are determined by a complex gradient of natural and anthropogenic disturbances. Mangrove pollen from surface sediments and the existing vegetation and geomorphology are close interrelated. Plant pollen of mangrove and salt marsh reflects environmental and disturbance conditions, and also reveals forest types. Forest dynamics in both coasts and their sensitivity of to anthropogenic processes are well documented in the Late Quaternary fossil record. Our studies of short and long term allow us to predict the dynamics of mangroves under different scenarios of climate change and anthropogenic stress factors that are operating in Colombian coasts. Future research arises from these results on mangrove forests dynamics, sea-level rise at a fine scale using palynology, conservation biology, and carbon dynamics.

  15. Advances in understanding and managing atopic dermatitis

    PubMed Central

    Barton, Michael; Sidbury, Robert

    2015-01-01

    Atopic dermatitis is a chronic, pruritic skin disease characterized by an improperly functioning skin barrier and immune dysregulation. We review proposed atopic dermatitis pathomechanisms, emphasizing how these impact current perspectives on natural history, role of allergic sensitization, and future therapeutic targets. PMID:26918129

  16. Recent advances in understanding norovirus pathogenesis.

    PubMed

    Karst, Stephanie M; Tibbetts, Scott A

    2016-11-01

    Noroviruses constitute a family of ubiquitous and highly efficient human pathogens. In spite of decades of dedicated research, human noroviruses remain a major cause of gastroenteritis and severe diarrheal disease around the world. Recent findings have begun to unravel the complex mechanisms that regulate norovirus pathogenesis and persistent infection, including the important interplay between the virus, the host immune system, and commensal bacteria. Herein, we will summarize recent research developments regarding norovirus cell tropism, the use of M cells, and commensal bacteria to facilitate norovirus infection, and virus, host, and bacterial determinants of persistent norovirus infections. J. Med. Virol. 88:1837-1843, 2016. © 2016 Wiley Periodicals, Inc. PMID:27110852

  17. Recent advances in understanding urethral lichen sclerosus

    PubMed Central

    Mangera, Altaf; Osman, Nadir; Chapple, Christopher

    2016-01-01

    Lichen sclerosus affecting the male genitalia is a poorly understood but potentially devastating condition. The natural history of the condition is beginning to be understood better with longer follow-up of patients. Recent long-term data suggest that circumcision for lichen sclerosus limited to the prepuce may not be curative as was once thought. In addition, surgical treatments should be followed up for longer periods as recurrences may occur after urethroplasty and perineal urethrostomy. PMID:26918163

  18. Advances in understanding of bile acid diarrhea

    PubMed Central

    Camilleri, Michael

    2014-01-01

    Bile acids (BA) are actively reabsorbed in the terminal ileum by the apical Na+-dependent bile salt transporter. This review addresses the epidemiology, pathophysiology, diagnosis and treatment of BA diarrhea (BAD). BAD is typically caused by ileal resection or disease; 25–33% of patients with chronic functional diarrhea or irritable bowel syndrome-diarrhea (IBS-D) have BAD, possibly from deficiency in the ileal hormone, FGF-19, which normally provides feedback inhibition of BA synthesis. Diagnosis of BAD is typically based on reduced BA retention of radiolabeled BA (75SeHCAT), increased BA synthesis (serum C4) or increased fecal BA loss. In clinical practice, diagnosis is often based on response to BA sequestrants (e.g., cholestyramine or colesevelam). Diagnostic tests for BA malabsorption (BAM) need to be used more extensively in clinical practice. In the future, farnesoid X receptor agonists that stimulate ileal production of FGF-19 may be alternative treatments of BAD. PMID:24410472

  19. Advances in understanding of bile acid diarrhea.

    PubMed

    Camilleri, Michael

    2014-01-01

    Bile acids (BA) are actively reabsorbed in the terminal ileum by the apical Na(+)-dependent bile salt transporter. This review addresses the epidemiology, pathophysiology, diagnosis and treatment of BA diarrhea (BAD). BAD is typically caused by ileal resection or disease; 25-33% of patients with chronic functional diarrhea or irritable bowel syndrome-diarrhea (IBS-D) have BAD, possibly from deficiency in the ileal hormone, FGF-19, which normally provides feedback inhibition of BA synthesis. Diagnosis of BAD is typically based on reduced BA retention of radiolabeled BA ((75)SeHCAT), increased BA synthesis (serum C4) or increased fecal BA loss. In clinical practice, diagnosis is often based on response to BA sequestrants (e.g., cholestyramine or colesevelam). Diagnostic tests for BA malabsorption (BAM) need to be used more extensively in clinical practice. In the future, farnesoid X receptor agonists that stimulate ileal production of FGF-19 may be alternative treatments of BAD. PMID:24410472

  20. Approaches for advancing scientific understanding of macrosystems

    USGS Publications Warehouse

    Levy, Ofir; Ball, Becky A.; Bond-Lamberty, Ben; Cheruvelil, Kendra S.; Finley, Andrew O.; Lottig, Noah R.; Surangi W. Punyasena; Xiao, Jingfeng; Zhou, Jizhong; Buckley, Lauren B.; Filstrup, Christopher T.; Keitt, Tim H.; Kellner, James R.; Knapp, Alan K.; Richardson, Andrew D.; Tcheng, David; Toomey, Michael; Vargas, Rodrigo; Voordeckers, James W.; Wagner, Tyler; Williams, John W.

    2014-01-01

    The emergence of macrosystems ecology (MSE), which focuses on regional- to continental-scale ecological patterns and processes, builds upon a history of long-term and broad-scale studies in ecology. Scientists face the difficulty of integrating the many elements that make up macrosystems, which consist of hierarchical processes at interacting spatial and temporal scales. Researchers must also identify the most relevant scales and variables to be considered, the required data resources, and the appropriate study design to provide the proper inferences. The large volumes of multi-thematic data often associated with macrosystem studies typically require validation, standardization, and assimilation. Finally, analytical approaches need to describe how cross-scale and hierarchical dynamics and interactions relate to macroscale phenomena. Here, we elaborate on some key methodological challenges of MSE research and discuss existing and novel approaches to meet them.