Sample records for aasetre dagmar hagen

  1. From the Outside In: Getting Physical with Exercises Inspired by Stella Adler and Uta Hagen.

    ERIC Educational Resources Information Center

    Miller, Bruce

    2002-01-01

    Proposes that teaching students to find and play appropriate actions helps them tell the story of a play and create character better than if they focused on emotions. Discusses Stella Adler and Uta Hagen, two acting teachers who advocated this physical approach. Presents two exercises: "justify and connect," and "enter a room." (PM)

  2. Health assessment for Hagen Farm Site, Stoughton, Wisconsin, Region 5. CERCLIS No. WID980610059. Preliminary report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    Hagen Farm is listed on the National Priorities List. The site, in the township of Dunkirk, Dane County, Wisconsin, was found to be contaminating surrounding ground water in the early 1980's. The site was used as a dumpsite for industrial waste. The media of concern are ground water and on-site soil contamination. Soil contamination data are not available. The existing on-site data show ground water contamination at the monitoring-well sites. These contaminants at maximum levels include: xylenes, 27,000 ppb; ethylbenzene, 7000 ppb; toluene, 260 ppb; tetrahydrofuran, 56,000 ppb; chlorobenzene, 24 ppb. The Hagen Farm Site represents a public health concern.more » The ground water contamination has been clearly demonstrated, and continued private well use has been established. The ongoing use of the Sundby Sand and Gravel Well for industrial use and use in toilet facilities exposes workers to an unknown contamination.« less

  3. Commentary: So Was It Worth It? a Commentary on Fricke Et Al. and Hagen Et Al. (2017)

    ERIC Educational Resources Information Center

    McCartney, Elspeth

    2017-01-01

    Fricke et al. and Hagen et al. (2017) each report on large-scale pragmatic randomised controlled trials delivered in schools or nurseries, investigating language interventions for vulnerable children and showing moderate positive effect sizes. Such research is part of a recent development of 'what works' research in England, and the number of…

  4. A novel experimental setup to study the Hagen-Poiseuille and Bernoulli equations for a gas and determination of the viscosity of air

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Surajit

    2015-11-01

    We have performed an experiment in which we have determined the viscosity of air using the Hagen-Poiseuille equation in the proper range of the Reynolds number (Re). The experiment is novel and simple which students even at high school level can perform with minimal equipment.The experiment brings out the fact that determination of viscosity of a fluid is possible only when its Reynolds number is sufficiently small. At very large Reynolds number, the gas behaves more like an inviscid fluid and its flow rate satisfies Bernoulli’s equation. In the intermediate range of the Reynolds number, the flow rate satisfies neither the Hagen-Poiseuille equation nor the Bernoulli equation. A wide range of Reynolds numbers from 40 to about 5000 has been studied. In the case of air, this large range has not shown any sign of turbulence.

  5. Hantaan virus surveillance targeting small mammals at Dagmar North Training Area, Gyeonggi Province, Republic of Korea, 2001-2005.

    PubMed

    Klein, Terry A; Kang, Hae Ji; Gu, Se Hun; Moon, Sungsil; Shim, So-Hee; Park, Yon Mi; Lee, Sook-Young; Kim, Heung-Chul; Chong, Sung-Tae; O'Guinn, Monica; Lee, John S; Turell, Michael J; Song, Jin-Won

    2011-12-01

    In response to a hemorrhagic fever with renal syndrome case in November 2000, a seasonal rodent-borne disease surveillance program was initiated at Dagmar North Training Area (DNTA), Gyeonggi Province, Republic of Korea. From April 2001-December 2005, 1,848 small mammals were captured. Apodemus agrarius accounted for 92.5%, followed by Mus musculus (3.6%), Crocidura lasiura (2.1%), and Microtus fortis (1.1%). Three species of rodents were found to be antibody-positive (Ab+) for Hantaan virus (HTNV): A. agrarius (22.3%), M. musculus (9.1%), and M. fortis (5.0%). Ab+ rates for A. agrarius increased with increasing weight (age), except for those weighing <10 g. The peak HTNV transmission period in Korea coincided with the peak reproductive potential of A. agrarius during the fall (August/September) surveys. HTNV strains from DNTA were distinct from HTNV strains from the People's Republic of China. From these studies, more accurate risk assessments can be developed to better protect personnel from rodent-borne diseases. © 2011 The Society for Vector Ecology.

  6. Seasonal and environmental determinants of leptospirosis and scrub typhus in small mammals captured at a U.S. military training site (Dagmar North), Republic of Korea, 2001-2004.

    PubMed

    Payne, Kevin S; Klein, Terry A; Otto, Jean L; Kim, Heung-Chul; Chong, Sung-Tae; Ha, Si Jung; Gu, Se Hun; Jeong, Ji Hae; Baek, Luck Ju; Song, Jin-Won

    2009-10-01

    This study sought to identify seasonal and environmental determinants of scrub typhus, murine typhus, and leptospirosis in small mammals trapped at Dagmar North training area, Gyeonggi Province, South Korea. Small mammals received titer assays to the aforementioned diseases. Logistic regression analyses were conducted to determine whether associations existed between risk of small-mammal infection and independent variables such as season of capture, habitat, small-mammal species, and sex. Murine typhus was not detected among the animals assayed. Risk of scrub typhus infection was associated with season, habitat, and small-mammal species. Risk of leptospirosis infection was associated with season and habitat. These findings indicate determinants of infection exist for scrub typhus and leptospirosis at this training site. This information can be used for developing appropriate preventive medicine plans and coordinating troop activity during periods of reduced exposure decreasing the likelihood of disease transmission to humans.

  7. Studies on stoneflies (Plecoptera) of Colorado with eastern faunal affinities, including a new state record of the midwestern salmonfly, Pteronarcys pictetii hagen (Plecoptera: Pteronarcyidae)

    USGS Publications Warehouse

    Zuellig, R.E.; Kondratieff, B.C.; Hood, R.W.

    2006-01-01

    Pteronarcys pictetii Hagen nymphs were collected and reared from the South Platte River at Julesburg in eastern Colorado. Including P. pictetii, eight species are now known from Colorado that exhibit eastern North American affinities, Paracapnia angulata Hanson, Taeniopteryx burksi Ricker and Ross, Taeniopteryx parvula Banks, Acroneuria abnormis (Newman), Perlesta decipiens (Walsh), Isoperla bilineata (Say), and Isoperla marlynia (Needham and Claassen). A brief discussion of the dispersal of these species into Colorado is presented.

  8. A comprehensive photometric study of dynamically evolved small van den Bergh-Hagen open clusters

    NASA Astrophysics Data System (ADS)

    Piatti, Andrés E.

    2016-12-01

    We present results from Johnson UBV, Kron-Cousins RI and Washington CT1T2 photometries for seven van den Bergh-Hagen (vdBH) open clusters, namely, vdBH 1, 10, 31, 72, 87, 92, and 118. The high-quality, multiband photometric data sets were used to trace the cluster stellar density radial profiles and to build colour-magnitude diagrams and colour-colour diagrams from which we estimated their structural parameters and fundamental astrophysical properties. The clusters in our sample cover a wide age range, from ˜60 Myr up to 2.8 Gyr, are of relatively small size (˜1-6 pc) and are placed at distances from the Sun which vary between 1.8 and 6.3 kpc, respectively. We also estimated lower limits for the cluster present-day masses as well as half-mass relaxation times (tr). The resulting values in combination with the structural parameter values suggest that the studied clusters are in advanced stages of their internal dynamical evolution (age/tr ˜ 20-320), possibly in the typical phase of those tidally filled with mass segregation in their core regions. Compared to open clusters in the solar neighbourhood, the seven vdBH clusters are within more massive (˜80-380 M⊙), with higher concentration parameter values (c ˜ 0.75-1.15) and dynamically evolved ones.

  9. Effect of temperature on heavy metal toxicity to juvenile crayfish, Orconectes immunis (Hagen).

    PubMed

    Khan, M A Q; Ahmed, S A; Catalin, Bogdon; Khodadoust, A; Ajayi, Oluwaleke; Vaughn, Mark

    2006-10-01

    The acute toxicity of four selected heavy metals to juvenile crayfish Orconectes immunis (Hagen) (1-2 g wet body wt. each) at room temperature increased in the following order: cadmium (x3) < copper (x10) < zinc (x2) < lead. The toxicity of these metals to crayfish acclimated at 17, 20, 23/24, and 27 degrees C increased with temperature (by 7-20% between 20 and 24 degrees C and 14-26% between 20 and 27 degrees C) as judged by the lowering of LT(50) (time to kill 50% of test animals at a fixed concentration) values. A 4 degrees C rise in temperature (from 20 to 24 degrees C), which increased the toxicity of copper by about 7%, increased the rate of oxygen consumption by about 34%. Heavy metals inhibited the rate of oxygen consumption at all temperatures. In 20 degrees C-acclimated crayfish, copper caused about 17% inhibition of oxygen consumption compared to about 7-12% by other metals including the most toxic cadmium. A 3-4 degrees C rise in temperature tripled the inhibitory effect of copper (20%), cadmium and zinc (26 and 18%, respectively), but not of lead, on oxygen consumption. A 7 degrees C-rise in temperature (from 20 to 27 degrees C) increased the inhibitory effect of heavy metals, including lead, on oxygen consumption by up to 54% in the case of copper. The data indicate that rising global temperatures (currently 0.60 degrees C) associated with climate change can have the potential to increase the sensitivity of aquatic animals to heavy metals in their environment.

  10. Toxicity and Metabolism of Zeta-Cypermethrin in Field-Collected and Laboratory Strains of the Neotropical Predator Chrysoperla externa Hagen (Neuroptera: Chrysopidae).

    PubMed

    Haramboure, M; Smagghe, G; Niu, J; Christiaens, O; Spanoghe, P; Alzogaray, R A

    2017-06-01

    Resistance to pesticides has been studied in several insect pests, but information on the natural enemies of pests-including the Neotropical predator Chrysoperla externa Hagen (Neuroptera: Chrysopidae), a major biological control agent in South America-is lacking. We report here a comparative study between a field-collected strain of C. externa subjected to monthly sprayings of pyrethroids and neonicotinoids and a laboratory strain without exposure to pesticides. The tolerance of both strains against zeta-cypermethrin was similar, and addition of the synergist piperonyl butoxide increased the toxicity by 30% in both strains. Gas-chromatography analyses and mixed-function-oxidase measurements indicated similar values in both strains and also confirmed the key role of oxidative metabolism in this species. Because C. externa has maintained a tolerance to zeta-cypermethrin without previous pesticide exposure, this species could potentially be mass-reared and released in fields in the presence of pesticide pressure.

  11. Identification, Expression and IAA-Amide Synthetase Activity Analysis of Gretchen Hagen 3 in Papaya Fruit (Carica papaya L.) during Postharvest Process

    PubMed Central

    Liu, Kaidong; Wang, Jinxiang; Li, Haili; Zhong, Jundi; Feng, Shaoxian; Pan, Yaoliang; Yuan, Changchun

    2016-01-01

    Auxin plays essential roles in plant development. Gretchen Hagen 3 (GH3) genes belong to a major auxin response gene family and GH3 proteins conjugate a range of acylsubstrates to alter the levels of hormones. Currently, the role of GH3 genes in postharvest physiological regulation of ripening and softening processes in papaya fruit is unclear. In this study, we identified seven CpGH3 genes in a papaya genome database. The CpGH3.1a, CpGH3.1b, CpGH3.5, CpGH3.6, and CpGH3.9 proteins were identified as indole-3-acetic acid (IAA)-specific amido synthetases. We analyzed the changes in IAA-amido synthetase activity using aspartate as a substrate for conjugation and found a large increase (over 5-fold) during the postharvest stages. Ascorbic acid (AsA) application can extend the shelf life of papaya fruit. Our data showed that AsA treatment regulates postharvest fruit maturation processes by promoting endogenous IAA levels. Our findings demonstrate the important role of GH3 genes in the regulation of auxin-associated postharvest physiology in papaya. PMID:27812360

  12. Suitability of leguminous cover crop pollens as food source for the green lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae).

    PubMed

    Venzon, Madelaine; Rosado, Maria C; Euzébio, Denise E; Souza, Brígida; Schoereder, José H

    2006-01-01

    Diversification of crops with species that provide suitable pollen for predators may reduce pest population on crops by enhancing predator effectiveness. In this paper we evaluated the suitability of leguminous cover crop pollens to the predatory green lacewing Chrysoperla externa (Hagen). The predator is commonly found in coffee agroecosystems and the plant species tested were pigeon pea and sunn hemp, which are used in organic coffee systems. Newly emerged females and males of C. externa were reared on diets containing pollen of pigeon pea, sunn hemp, or castor bean, used as a control. The reproductive success of C. externa was evaluated when females fed the pollen species and when honey was added to the diets, to verify the predator need for an extra carbohydrate source. Similar intrinsic growth rates were found for females fed on pigeon pea pollen and on sunn hemp pollen but these rates increased significantly when honey was added to the diets. Females fed with pigeon pea pollen plus honey and with sunn hemp pollen plus honey had higher intrinsic growth rates than those fed with castor bean pollen plus honey. Females fed on castor bean pollen only or on honey only, did not oviposit. Leguminous pollen species were equally suitable for C. externa especially when they were complemented with honey. The results suggest that to successfully enhance predator effectiveness, organic coffee plantation should be diversified with plant providing pollen in combination with plant providing nectar.

  13. The Hagen-Poiseuille, Plane Couette and Poiseuille Flows Linear Instability and Rogue Waves Excitation Mechanism

    NASA Astrophysics Data System (ADS)

    Chefranov, Sergey; Chefranov, Alexander

    2016-04-01

    Linear hydrodynamic stability theory for the Hagen-Poiseuille (HP) flow yields a conclusion of infinitely large threshold Reynolds number, Re, value. This contradiction to the observation data is bypassed using assumption of the HP flow instability having hard type and possible for sufficiently high-amplitude disturbances. HP flow disturbance evolution is considered by nonlinear hydrodynamic stability theory. Similar is the case of the plane Couette (PC) flow. For the plane Poiseuille (PP) flow, linear theory just quantitatively does not agree with experimental data defining the threshold Reynolds number Re= 5772 ( S. A. Orszag, 1971), more than five-fold exceeding however the value observed, Re=1080 (S. J. Davies, C. M. White, 1928). In the present work, we show that the linear stability theory conclusions for the HP and PC on stability for any Reynolds number and evidently too high threshold Reynolds number estimate for the PP flow are related with the traditional use of the disturbance representation assuming the possibility of separation of the longitudinal (along the flow direction) variable from the other spatial variables. We show that if to refuse from this traditional form, conclusions on the linear instability for the HP and PC flows may be obtained for finite Reynolds numbers (for the HP flow, for Re>704, and for the PC flow, for Re>139). Also, we fit the linear stability theory conclusion on the PP flow to the experimental data by getting an estimate of the minimal threshold Reynolds number as Re=1040. We also get agreement of the minimal threshold Reynolds number estimate for PC with the experimental data of S. Bottin, et.al., 1997, where the laminar PC flow stability threshold is Re = 150. Rogue waves excitation mechanism in oppositely directed currents due to the PC flow linear instability is discussed. Results of the new linear hydrodynamic stability theory for the HP, PP, and PC flows are published in the following papers: 1. S.G. Chefranov, A

  14. 75 FR 981 - Certain Activated Carbon From the People's Republic of China: Notice of Rescission of Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-07

    ... Rolf C. Hagen (USA), Corp. (``Hagen'') requesting a scope ruling that certain fish tank filter products... with 19 CFR 351.225(k)(1) that the commercial fish tank filter products described in the Hagen scope... determined the scope language to be dispositive, the Department found the fish tank filter products described...

  15. An Inside Job

    ERIC Educational Resources Information Center

    Wills, Denise Kersten

    2007-01-01

    No hovering administrators. No high-stakes tests. No pestering parents. Barb Hagen teaches murderers and sex offenders, and she loves her work. This article describes the experiences of Barb Hagen, a prison education teacher. Barb Hagen could not save the troubled middle-schoolers she taught for 20 years. Now she helps inmates get their lives back…

  16. Reducing Long-Term Costs While Preserving a Robust Strategic Airlift Fleet: Options for the Current Fleet and Next-Generation Aircraft

    DTIC Science & Technology

    2013-01-01

    Ghashghai, Jeff Hagen, Thomas Hamilton, Gregory G. Hildebrandt , Yool Kim, Robert S. Leonard, Rosalind Lewis, Elvira N. Loredo, Daniel M. Norton, David T...Joan Cornuet, Mel Eisman, Chris Fitzmartin, Jean R. Gebman, Elham Ghashghai, Jeff Hagen, Thomas Hamilton, Gregory G. Hildebrandt , Yool Kim, Robert...Hagen, Thomas Hamilton, Gregory G. Hildebrandt , Yool Kim, Robert S. Leonard, Rosa- lind Lewis, Elvira N. Loredo, Daniel M. Norton, David T. Orletsky

  17. The Crucial Role of the Operational Artist: A Case Study of Operation Barbarossa

    DTIC Science & Technology

    2017-05-25

    historical case study helps to develop a better understanding of operational art today. Future studies might focus on the limitations and opportunities...The Crucial Role of the Operational Artist: A Case Study of Operation Barbarossa A Monograph by LTC (GS) Hagen H. Ruppelt German Army...a Case Study of Operation Barbarossa 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) LTC (GS) Hagen H

  18. Breaking new ground: the story of Dagmar Berne.

    PubMed

    Moorhead, Robert

    2008-01-01

    In 1885 a young country girl enrolled in medicine at Sydney University. She was the first woman in Australia to enroll in a medical school. The medical school at this time was heavily influenced by academics who had graduated from the University of Edinburgh. At one point in her medical education she experienced difficulties with her examinations, the reasons for which are a point for debate. Under the mentorship of a famous British female medical practitioner who was visiting Australia at the time, she continued her studies in the United Kingdom. Here she was successful and returned to practice in New South Wales in 1895. Her experience of medical education was not without suffering. This young woman became part of an international group of women who at the time were trying to break into a field dominated by men.

  19. Pitch Elevation in Male-to-female Transgender Persons-the Würzburg Approach.

    PubMed

    Meister, Jonas; Hagen, Rudolf; Shehata-Dieler, Wafaa; Kühn, Heike; Kraus, Fabian; Kleinsasser, Norbert

    2017-03-01

    The present study reports objective and subjective voice results of Wendler's glottoplasty modified by Hagen. This is an outcomes research study. A total of 21 patients underwent Wendler's glottoplasty modified by Hagen. Parameters in the follow-up session were laryngoscopy, voice range profile, Voice Handicap Index, Life Satisfaction Questionnaire, and a visual analog scale for individual satisfaction with the voice. The fundamental frequency was elevated into the typical female fundamental frequency range. Furthermore, an elevation of the lower frequency limit was shown without a reduction of the frequency range. About one third of the population feels affected by the restricted dynamic range. This change of the vocal pitch is seen as part of the voice feminization by some of the patients. The Dysphonia Severity Index as a marker for voice quality was unchanged. Subjective satisfaction with the voice showed a strong correlation with the individual elevation of the pitch. Wendler's glottoplasty modified by Hagen is an effective and low-risk method of raising the vocal pitch of male-to-female transgender persons. However, elevated Scores of the Voice Handicap Index indicated that in everyday life, transgender persons continue to feel handicapped because of their voice. Another indicator for the lack of social acceptance and integration is the reduced general life satisfaction in the Life Satisfaction Questionnaire especially in the domain "friends, acquaintances, relatives." Therefore, a better multidisciplinary therapy concept for voice feminization is necessary. Copyright © 2017. Published by Elsevier Inc.

  20. Prevalence of Visible and Occult Blood on the Surfaces of Fiberoptic Bronchoscopes

    DTIC Science & Technology

    2000-10-01

    Mycobacterium chelonae and Rhodotorula rubra) in the 2 suction channels of fiberoptic endoscopes. (Cox, deBorja, & Bach, 1997; Hagan, Koltz, Bartholomew...Hagen, M.E., Klotz, S.A., Bartholomew, W., Potter, L., & Nelson, M. (1996). A pseudoepidemic of rhodotorula rubra: A marker for microbial

  1. Mitochondrial DNA genetic diversity of the drywood termites Incisitermes minor and I. snyderi

    USDA-ARS?s Scientific Manuscript database

    The western drywood termite, Incisitermes minor (Hagen) and the light southern drywood termite I. snyderi (Light) are common drywood termites in southwestern and southern United States, respectively. Despite the economic importance of these two species, no information exists on the mitochondrial gen...

  2. Metamaterials for Miniaturization of Optical Components

    DTIC Science & Technology

    2014-09-24

    elementary EM fields are exactly the Maxwell equations with proper conserved currents; (iii) a free charge moves uniformly preserving up to the...Disordered Systems -- A Conference in Honor of Leonid Pastur , Hagen, Germany, Some Mathematical Problems in a Neoclassical Theory of Electric Charges

  3. "Campus" - An Agent-Based Platform for Distance Education.

    ERIC Educational Resources Information Center

    Westhoff, Dirk; Unger, Claus

    This paper presents "Campus," an environment that allows University of Hagen (Germany) students to connect briefly to the Internet but remain represented by personalized, autonomous agents that can fulfill a variety of information, communication, planning, and cooperation tasks. A brief survey is presented of existing mobile agent system…

  4. From Content to Practice: Sharing Educational Practice in Edu-Sharing

    ERIC Educational Resources Information Center

    Klebl, Michael; Kramer, Bernd J.; Zobel, Annett

    2010-01-01

    For technology-enhanced learning, the idea of "learning objects" transfers the technologies of content management, methods of software engineering and principles of open access to educational resources. This paper reports on CampusContent, a research project and competence centre for e-learning at FernUniversitat in Hagen that designed…

  5. Adolescent English Language Learners' Second Language Literacy Engagement in World of Warcraft (WoW)

    ERIC Educational Resources Information Center

    Li, Zhuo

    2011-01-01

    As noted by researchers (Funk, Hagen, & Schimming, 1999; Squire, 2006; Williams, 2003), many youth today spend more time playing in digital worlds than reading, or watching TV or films. Though many people, parents and teachers, still take video games as mere entertainment, "gaming culture" (Sanford & Madill, 2007) and "game…

  6. York Papers in Linguistics 14.

    ERIC Educational Resources Information Center

    Harlow, S. J., Ed.; Warner, A. R., Ed.

    Papers on a variety of linguistic topics include six papers from a Festschrift and nine others, as follows: "Attitudes Towards English as a Possible Lingua Franca in Switzerland" (Urs Durmuller); "Functional Stability and Structural Levelling of Dialects: The Case of Maastricht" (Anton M. Hagen, Henk Munstermann); "On the…

  7. "Doing Gender" at "Body Worlds": Embodying Field Trips as Affective Educational Experience

    ERIC Educational Resources Information Center

    Davidson, Joyce; Huff, Leah; Bridgen, Jen; Carolan, Andrea; Chang, Ashley; Ennis, Katherine; Loynes, Kathryn; Miller, Jen

    2009-01-01

    This paper discusses the background, experience and outcomes of an explicitly feminist field trip to Gunther von Hagen's "Body Worlds 2: The Anatomical Exhibition of Real Human Bodies". The cultural landscape of this exhibition materialized gendered geographies very powerfully, facilitating observation and analysis of embodied and emotional,…

  8. Investigating Students' Usage and Acceptance of Electronic Books

    ERIC Educational Resources Information Center

    Sieche, Susan; Krey, Birte; Bastiaens, Theo

    2013-01-01

    The purpose of this study is to investigate students' usage and acceptance of electronic books. Factors correlating with students' attitude towards e-books were examined using the Technology Acceptance Model (Davis, Bagozzi, & Warshaw 1989). A questionnaire was administered online for students at University of Hagen. Results indicate that…

  9. Future Foreign Language Teachers' Social and Cognitive Collaboration in an Online Environment

    ERIC Educational Resources Information Center

    Arnold, Nike; Ducate, Lara

    2006-01-01

    Discussion boards provide an interactive venue where new and future language teachers can reflect, evaluate, solve problems or simply exchange ideas (e.g., Bonk, Hansen, Grabner-Hagen, Lazar, & Mirabelli, 1996; DeWert, Babinski, & Jones, 2003; Kumari, 2001; Pawan, Paulus, Yalcin, & Chang, 2003). In addition, encouraging future teachers to learn…

  10. The Changing Role of Instructors in Distance Education: Impact on Tool Support.

    ERIC Educational Resources Information Center

    Biedebach, Anke; Bomsdorf, Birgit; Schlageter, Gunter

    At the university of Hagen a lot of experience exists in performing Web-based teaching and in implementing tools supporting e-learning. To share this knowledge, (inexperienced) instructors more and more ask for tool-based assistance in designing and administrating e-learning courses. Considering experience from other universities, it becomes…

  11. Policing The Homeland: Choosing The Intelligent Option

    DTIC Science & Technology

    2006-03-01

    fagioli , I truly appreciated his perspectives. To my Half Dome comrades, Commander Barry Compagnoni, Captain Jay Hagen, and Darren Chen, you made NPS a...grateful for my loving wife, Andrea . She is not only my best friend, but also my greatest advocate. Her support has always been instrumental for me in

  12. Selective Attention of Impulsive and Reflective Children. Research Report No. 66.

    ERIC Educational Resources Information Center

    Egeland, Byron; Thibodeau, Anne

    The present investigation looked at selective attention in impulsive and reflective children using a central/incidental task similar to that used by Hagen, 1967. In order to examine developmental change in selective attention, children at kindergarten, second, and fifth grades were tested. The central recall task involved presenting the child with…

  13. Absorption and distribution of C14-labeled tetramine in relation to its possible use in animal damage control

    Treesearch

    M.A. Radwan

    1966-01-01

    Tetramethylenedisulphotetramine (tetramine) is an extremely toxic chemicaI (Hagen 1950).' Shortly after its discovery in Germany (Hecht and Henecka 1949L it was introduced in the United States and found useful as an experimental seed protectant in reforestation by direct seeding (Spencer 1954). The first indication of tetramine's systemic characteristics was...

  14. A Commonsense Approach to Intelligence, Surveillance, and Reconnaissance Operations

    DTIC Science & Technology

    2016-09-01

    effectively.  Notes 1. Gordon Lubold, “Pentagon to Sharply Expand U.S. Drone Flights over Next Four Years,” Wall Street Journal, 16 August 2015, http...white paper, 2015. 14. Carl Rhodes, Jeff Hagen, and Mark Westergren, A Strategies-to-Tasks Framework for Planning and Executing Intelligence

  15. A brief overview of current relationships of geography, statistics, and taxonomy with the classical integrated control concept

    USDA-ARS?s Scientific Manuscript database

    A classic paper on the integrated control concept appeared in the later part of the 1950’s, led by Vernon Stern, Ray Smith, Robert van den Bosch, and Kenneth Hagen. Numerous concepts and definitions were formulated at that time. In this presentation, a short philosophical summary will be presented...

  16. The Development of Visual and Auditory Selective Attention Using the Central-Incidental Paradigm.

    ERIC Educational Resources Information Center

    Conroy, Robert L.; Weener, Paul

    Analogous auditory and visual central-incidental learning tasks were administered to 24 students from each of the second, fourth, and sixth grades. The visual tasks served as another modification of Hagen's central-incidental learning paradigm, with the interpretation that focal attention processes continue to develop until the age of 12 or 13…

  17. Participatory and Dialogue Democracy in U.S. Mathematics Classrooms

    ERIC Educational Resources Information Center

    Mukhopadhyay, Shiuli

    2009-01-01

    Teaching math to reflect values of democracy has to begin with some consideration of how democracy is conceptualized. A review of various theories of democracy conducted by Hagen (1992) provides everyone with a good starting point as it identifies three primary forms of democracy: competitive, participatory, and dialogue. In this essay, the author…

  18. High Levels of Transmitted HIV Drug Resistance in a Study in Papua New Guinea.

    PubMed

    Lavu, Evelyn; Kave, Ellan; Mosoro, Euodia; Markby, Jessica; Aleksic, Eman; Gare, Janet; Elsum, Imogen A; Nano, Gideon; Kaima, Petronia; Dala, Nick; Gurung, Anup; Bertagnolio, Silvia; Crowe, Suzanne M; Myatt, Mark; Hearps, Anna C; Jordan, Michael R

    2017-01-01

    Papua New Guinea is a Pacific Island nation of 7.3 million people with an estimated HIV prevalence of 0.8%. ART initiation and monitoring are guided by clinical staging and CD4 cell counts, when available. Little is known about levels of transmitted HIV drug resistance in recently infected individuals in Papua New Guinea. Surveillance of transmitted HIV drug resistance in a total of 123 individuals recently infected with HIV and aged less than 30 years was implemented in Port Moresby (n = 62) and Mount Hagen (n = 61) during the period May 2013-April 2014. HIV drug resistance testing was performed using dried blood spots. Transmitted HIV drug resistance was defined by the presence of one or more drug resistance mutations as defined by the World Health Organization surveillance drug resistance mutations list. The prevalence of non-nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 16.1% (95% CI 8.8%-27.4%) and 8.2% (95% CI 3.2%-18.2%) in Port Moresby and Mount Hagen, respectively. The prevalence of nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 3.2% (95% CI 0.2%-11.7%) and 3.3% (95% CI 0.2%-11.8%) in Port Moresby and Mount Hagen, respectively. No protease inhibitor transmitted HIV drug resistance was observed. The level of non-nucleoside reverse transcriptase inhibitor drug resistance in antiretroviral drug naïve individuals recently infected with HIV in Port Moresby is amongst the highest reported globally. This alarming level of transmitted HIV drug resistance in a young sexually active population threatens to limit the on-going effective use of NNRTIs as a component of first-line ART in Papua New Guinea. To support the choice of nationally recommended first-line antiretroviral therapy, representative surveillance of HIV drug resistance among antiretroviral therapy initiators in Papua New Guinea should be urgently implemented.

  19. Cognitive Development and Down Syndrome: Age-Related Change on the Stanford-Binet Test (Fourth Edition)

    ERIC Educational Resources Information Center

    Couzens, Donna; Cuskelly, Monica; Haynes, Michele

    2011-01-01

    Growth models for subtests of the Stanford-Binet Intelligence Scale, 4th edition (R. L. Thorndike, E. P. Hagen, & J. M. Sattler, 1986a, 1986b) were developed for individuals with Down syndrome. Models were based on the assessments of 208 individuals who participated in longitudinal and cross-sectional research between 1987 and 2004. Variation…

  20. 77 FR 40946 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    .... Almeida (MA) Ronald B. Brown (ME) Trixie L. Brown (IN) Thomas L. Corey (IN) Brian G. Hagen (IL) Azizi A. Jamal (NJ) Willard L. Riggle (IN) Jose M. Suarez (TX) Lee F. Taylor (NJ) Barney J. Wade (MS) Richard G. Wendt (MS) Charles A. Winchell (OK) The exemptions are extended subject to the following conditions: (1...

  1. AFRRI (Armed Forces Radiobiology Research Institute) Reports, October-December 1989

    DTIC Science & Technology

    1989-02-01

    lack receptors for rhGM-CSF [16]. t.:is timu- (201. In contrast. Antman et al. reported that in patients with lation is likely to be mediated through...O*Hara PJ. Berkner K. Segal GM. Hagen FS. 22. Antman KS. Griffin JD. Elias A. Socinski M1A. Ryan L, Can- Adamson 1W 11986) Genomic cloning

  2. Interrelations of Fertility and Women's Labor Force Participation, With Particular Emphasis on the Effects of Education. Discussion Papers #388-77.

    ERIC Educational Resources Information Center

    Wolfe, Barbara

    The effect of more education for women on their fertility behavior is examined in this paper through the use of data from the National Bureau of Economic Research/Thorndike-Hagen sample (NBERTH) and a comparable group from the National Longitudinal Survey. The NBER-TH data are longitudinal 25-year histories of 5,083 white males and their families.…

  3. Design and Acquisition of Software for Defense Systems

    DTIC Science & Technology

    2018-02-14

    enterprise business systems and related information technology (IT) services, the role software plays in enabling and enhancing weapons systems often...3 The information in this chart was compiled from Christian Hagen, Jeff Sorenson, Steven Hurt...understanding to make an informed choice of final architecture. The Task Force found commercial practice starts with several competing architectures and

  4. Tree Hydraulics: How Sap Rises

    ERIC Educational Resources Information Center

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  5. An Assessment of the Available Evidence on the Returns to Military Training

    DTIC Science & Technology

    1977-07-01

    Hanushek Kassing McCall and Wallace Mason (1970) Nathan Associates Weinstein et al. Richardson (1967) Thorndike and Hagen (1957) u.s...Biderman Cutright Freeman Hanushek Kassing McCall and Wallace Mason (1970) Primary Purpose of the Study Analyze the vocational readjustment...that veterans do not receive a positive economic return from military voca- tional training. Mason (1970), Hanushek , Cutright, and Kassing reach

  6. The Role of Photographs and Films in Kettlewell's Popularizations of the Phenomenon of Industrial Melanism

    NASA Astrophysics Data System (ADS)

    Wÿss Rudge, David

    H.B.D. Kettlewell's investigations on the phenomenon of industrial melanism are generally referred to in textbooks and other popularizations of science as the classic demonstration of natural selection (Majerus 1989). A central question for historians of this episode is accounting for why public perceptions of the importance of Kettlewell's work have diverged from those of researchers who actually work on the phenomenon. In a recent paper published in Biology and Philosophy, Joel Hagen draws attention to the role Kettlewell and his colleagues played in idealizing his investigations as an example of controlled experimentation in their several retrospective popular accounts. The present essay discusses the important role photographic and film depictions of differential bird predation played in Kettlewell's popularizations. This analysis supports Hagen's contentions that Kettlewell deftly and strategically used these visual representations to command assent to his interpretation of the phenomenon and shore up claims about the scientific legitimacy and importance of his work. It nevertheless disputes that these images were intended to portray Kettlewell's experiments as an example of controlled experimentation. In a concluding section, the essay draws several morals from this analysis regarding the use of popularized articles and visual images to teach science.

  7. RAND Project Air Force Annual Report 2008

    DTIC Science & Technology

    2008-01-01

    Systems: Past Lessons and Future Recommendations, by Obaid Younossi, Mark A. Lorell, Kevin Brancato, Cynthia R. Cook, Mel Eisman, Bernard Fox, John C...Competency Development: Experience from Prince Sultan Air Base and Eskan Village in Saudi Arabia, by Laura Werber Castaneda, Lawrence M. Hanser, and...Proposal, by Michael R. Thirtle, Michael Boito, Ian P. Cook, Bernard Fox, Phyllis Gilmore, Michelle Grace, Jeff Hagen, Thomas Hamilton

  8. Gauge Invariance and the Goldstone Theorem

    NASA Astrophysics Data System (ADS)

    Guralnik, Gerald S.

    This paper was originally created for and printed in the "Proceedings of seminar on unified theories of elementary particles" held in Feldafing, Germany from July 5 to 16, 1965 under the auspices of the Max-Planck-Institute for Physics and Astrophysics in Munich. It details and expands upon the 1964 Guralnik, Hagen, and Kibble paper demonstrating that the Goldstone theorem does not require physical zero mass particles in gauge theories.

  9. Project Air Force Annual Report 2007

    DTIC Science & Technology

    2007-01-01

    China has developed options that would make it a formidable adversary, particularly in a conflict over Taiwan , which the United States remains...he focused on China’s relationship with Taiwan . Since then, he has worked with other RAND analysts, such as David Orletsky, Evan Medeiros, Keith Crane...Hamilton, engineers Jeff Hagen and David Vaughan, Air Force Fellow Michelle Grace, behavioral scientist Larry Hanser, and information scientist Herb Shukiar

  10. A RAND Analysis Tool for Intelligence, Surveillance, and Reconnaissance: The Collections Operations Model

    DTIC Science & Technology

    2008-01-01

    appropriate; scan cycle, emission interval, or emission probability; frequency bands; relative angular size of 2 Carl Rhodes, Jeff Hagen, and Mark...choices based on its own perceptions. An agent has autonomy. 2 In this report, “behaviors” are individual scripts , programs, instructions, or decision...relative angular size of main and side lobes (for directional signals); and the effective radiated power of each radiative lobe. With these parameters and

  11. Revolution at Sea Starts Here. A 1987 History of the Naval Surface Warfare Center

    DTIC Science & Technology

    1988-03-01

    MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10 . SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY...Blake, Mary H. Hagen, Mark E. Chase, Gary Kendrick, Barbara Wisdom, George L. Hamlin, Pamela 0. Lama, Marcella Westermeyer, and Dave Meggs. Without...needs over the next 10 to 20 years. These thrusts were to: * Emphasize development and integration of Shipboard Electronic Warfare Systems; * Increase

  12. Faint Photoelectric Photometric Standard Star Sequences

    DTIC Science & Technology

    1988-07-15

    data awaiting additional study which will result in published research papers . The following list is a compilation of the publications which have...Astrophysical Journal, 323, 271, 1987. papers in preparation.... 1. "The Open Cluster van den Bergh Hagen-Harris No. 99", by A. U. Landolt, C. L...REPORT For a Grant for Basic Scientific Research (AFOSR Grant No. 82-0192) from The Air Force Office of Scientific Research entitled FAINT

  13. Wetland Responses to Sea Level Rise in the Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Alizad, K.; Bilskie, M. V.; Hagen, S. C.; Medeiros, S. C.; Morris, J. T.

    2016-12-01

    Coastal regions are vulnerable to flood risk due to climate change, sea level rise, and wetland losses. The Northern Gulf of Mexico (NGOM) is a region in which extreme events are projected to be more intense under climate change and sea level rise scenarios [Wang et al., 2013; Bilskie et al., 2014]. Considering increased frequency and intensity of coastal flooding, wetlands are valuable natural resources that protect shorelines by dissipating waves and storm surges [Costanza et al., 2008]. Therefore, it is critical to investigate the response of salt marsh systems in different estuaries to sea level rise in the NGOM and their effects on storm surges to inform coastal managers to choose effective restoration plans. This research applies the coupled Hydro-MEM model [Alizad et al., 2016] to study three different estuarine systems in the NGOM. The model incorporates both sea level rise rate and feedbacks between physics and biology by coupling a hydrodynamic (ADCIRC) and salt marsh (MEM) model. The results of the model provide tidal hydrodynamics and biomass density change under four sea level rise projections during a 100-year period. The results are used to investigate marsh migration path in the estuarine systems. In addition, this study shows how marsh migration and biomass density change can impact storm surge modeling. The results imply the broader impacts of sea level rise on the estuarine systems in the NGOM. ReferencesAlizad, K., S. C. Hagen, J. T. Morris, P. Bacopoulos, M. V. Bilskie, J. Weishampel, and S. C. Medeiros (2016), A coupled, two-dimensional hydrodynamic-marsh model with biological feedback, Ecological Modeling, 327, 29-43. Bilskie, M. V., S. C. Hagen, S. C. Medeiros, and D. L. Passeri (2014), Dynamics of sea level rise and coastal flooding on a changing landscape, Geophysical Research Letters, 41(3), 927-934. Costanza, R., O. Pérez-Maqueo, M. L. Martinez, P. Sutton, S. J. Anderson, and K. Mulder (2008), The Value of Coastal Wetlands for Hurricane

  14. New species of the damselfly genus Argia from Mexico, Central America and Ecuador with an emphasis on Costa Rica (Insecta: Odonata: Coenagrionidae).

    PubMed

    Garrison, Rosser W; Ellenrieder, Natalia VON

    2017-02-20

    Seven new species of Argia are described, five of which occur in Costa Rica: Argia calverti n. sp. (Holotype ♂, Costa Rica, Cartago Prov., Tapantí Reserve, 1,310 m, 6 vii 1963, F. G. Thompson leg., in FSCA); Argia carolus n. sp. (Holotype ♂, Costa Rica, San José Prov., El Rodeo Biological Reserve, 7 km W of Villa Colón, 9°54' N, 84°16' W, 561 m, 10-13 vii 1990, T. W. Donnelly leg., in FSCA); Argia elongata n. sp. (Holotype ♂, Costa Rica, Cartago Prov., Reventazón river, SE of Turrialba by highway 10, 9°52'56'' N, 83°38'49'' W, 561 m, 10 viii 1979, R. W. & J. A. Garrison leg., in CSCA); Argia haberi n. sp. (Holotype ♂, Costa Rica, San José Prov., Bosque del Tolomuco, km 118 on Pan American highway, in seeps and trickles through brushy pasture on forested hillside, 9°28'18'' N, 83°41'48'' W, 1,710 m, 27 iii 2006, F. Sibley leg., in FSCA); Argia schorri n. sp. (Holotype ♂, Costa Rica, Puntarenas Prov., 2.8 mi E of Golfito, 8°39' N, 83°7' W, 35 m, 4 vii 1967, O. S. Flint, Jr. & M. A. Ortiz B. leg., in USNM), and two which are so far only known from Mexico and Ecuador respectively: Argia rudolphi n. sp. (Holotype ♂, Mexico, Puebla State, Zihuateutla, Sierra de Huauchinango, La Unión, in drainage area, 20°14'25'' N, 97°53'38'' W, 596 m, 21 v 1987, R. Novelo & A. Gómez leg., in CSCA) and Argia schneideri n. sp. (Holotype ♂, Ecuador, Napo Prov., Las Palmas, on Anzu river in Napo river watershed, 11 xii 1936, W. Clark-MacIntyre leg., in UMMZ). All the new species, as well as closely related species needed for diagnosis including A. anceps Garrison, A. cupraurea Calvert, A. cuprea (Hagen), A. extranea (Hagen), A. fissa Selys, A. fulgida Navás, A. oenea Hagen in Selys, A. popoluca Calvert, A. rhoadsi Calvert, and A. westfalli Garrison, are illustrated and diagnosed from their congeners and their known distribution areas are mapped.

  15. A Survey of Laser Lightning Rod Techniques

    DTIC Science & Technology

    1991-08-21

    impossibility of the LLR concept. 4 REFERENCES 1. Hagen, 1969: "Diffraction-limited high irradiance Nd- glass laser system, J. Appl. Phys., 40, 511-516. 2. Greig...study", Air Force Flight Dynamics Laboratory,, Technical Report AFFDL-TR-78-60. AD A063 847. 8. Schubert, C.N., Jr. and J.R. Lippert , 1979...pp. 132-135. 9. Lippert , J.R.,1978: "Laser-Induced Lightning Concept Exper- iment", Air Force Flight Dynamics Laboratory, Technical Report AFFDL-TR

  16. [ANATOMY AND BODIES: DEAD BODIES IN MUSEUMS FROM VAN RUYSCHA VON HAGENS].

    PubMed

    Marinozzi, Silvia

    2015-01-01

    The aim of the conference of which we are here publishing the proceedings, held in Rome at Sapienza-University in 2013, was to valorise the specific museological heritage of Italian Universities, in relation to analogous European and non-European Museums of Anatomy and Pathological Anatomy. A particular attention has been devoted to highlight the history of the origins and evolution of specific museological collections in order to focus reasons and circumstances of their foundation through the analysis of the signifcances, finctions and uses of anatomical parts or artifacts in different cultural contexts.

  17. Model of Transition from Laminar to Turbulent Flow

    NASA Astrophysics Data System (ADS)

    Kanda, Hidesada

    2001-11-01

    For circular pipe flows, a model of transition from laminar to turbulent flow has already been proposed and the minimum critical Reynolds number of approximately 2040 was obtained (Kanda, 1999). In order to prove the validity of the model, another verification is required. Thus, for plane Poiseuille flow, results of previous investigations were studied, focusing on experimental data on the critical Reynolds number Rc, the entrance length, and the transition length. Consequently, concerning the natural transition, it was confirmed from the experimental data that (i) the transition occurs in the entrance region, (ii) Rc increases as the contraction ratio in the inlet section increases, and (iii) the minimum Rc is obtained when the contraction ratio is the smallest or one, and there is no-bellshaped entrance or straight parallel plates. Its value exists in the neighborhood of 1300, based on the channel height and the average velocity. Although, for Hagen-Poiseuille flow, the minimum Rc is approximately 2000, based on the pipe diameter and the average velocity, there seems to be no significant difference in the transition from laminar to turbulent flow between Hagen-Poiseuille flow and plane Poiseuille flow (Kanda, 2001). Rc is determined by the shape of the inlet. Kanda, H., 1999, Proc. of ASME Fluids Engineering Division - 1999, FED-Vol. 250, pp. 197-204. Kanda, H., 2001, Proc. of ASME Fluids Engineering Division - 2001.

  18. Photoluminescence and Lasing from Deoxyribonucleic Acid Thin Films Doped With Sulforhodamine

    DTIC Science & Technology

    2007-03-20

    sulforhodamine Z. Yu, W. Li, J. A. Hagen, Y. Zhou, D. Klotzkin, J. G. Grote, and A. J. Steckl Thin solid films of salmon DNA have been fabricated by...study is de- rived from salmon sperm14 and was provided by the Chitose Institute of Science and Technology (CIST) in Japan. After purification and...films. These conditions produced DNA–CTMA films of 80 nm and PMMA films of 140 nm. The films were baked in a vacuum oven at 30 mbars and 80 °C for 60

  19. A Dynamic Flood Inundation Model Framework to Assess Coastal Flood Risk in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Bilskie, M. V.; Hagen, S. C.; Passeri, D. L.; Alizad, K.; Medeiros, S. C.; Irish, J. L.

    2015-12-01

    Coastal regions around the world are susceptible to a variety of natural disasters causing extreme inundation. It is anticipated that the vulnerability of coastal cities will increase due to the effects of climate change, and in particular sea level rise (SLR). A novel framework was developed to generate a suite of physics-based storm surge models that include projections of coastal floodplain dynamics under climate change scenarios: shoreline erosion/accretion, dune morphology, salt marsh migration, and population dynamics. First, the storm surge inundation model was extensively validated for present day conditions with respect to astronomic tides and hindcasts of Hurricane Ivan (2004), Dennis (2005), Katrina (2005), and Isaac (2012). The model was then modified to characterize the future outlook of the landscape for four climate change scenarios for the year 2100 (B1, B2, A1B, and A2), and each climate change scenario was linked to a sea level rise of 0.2 m, 0.5 m, 1.2 m, and 2.0 m. The adapted model was then used to simulate hurricane storm surge conditions for each climate scenario using a variety of tropical cyclones as the forcing mechanism. The collection of results shows the intensification of inundation area and the vulnerability of the coast to potential future climate conditions. The methodology developed herein to assess coastal flooding under climate change can be performed across any coastal region worldwide, and results provide awareness of regions vulnerable to extreme flooding in the future. Note: The main theme behind this work is to appear in a future Earth's Future publication. Bilskie, M. V., S. C. Hagen, S. C. Medeiros, and D. L. Passeri (2014), Dynamics of sea level rise and coastal flooding on a changing landscape, Geophysical Research Letters, 41(3), 927-934. Parris, A., et al. (2012), Global Sea Level Rise Scenarios for the United States National Climate AssessmentRep., 37 pp. Passeri, D. L., S. C. Hagen, M. V. Bilskie, and S. C. Medeiros

  20. Assessing the Effects of Sea Level Rise on Plum Island Estuary Marshes Using a Hydrodynamic-marsh Modeling Tool

    NASA Astrophysics Data System (ADS)

    Demissie, H. K.; Bilskie, M. V.; Hagen, S. C.; Morris, J. T.; Alizad, K.

    2015-12-01

    Sea level rise (SLR) can significantly impact both human and ecological habitats in coastal and inland regions. Studies show that coastal estuaries and marsh systems are at the risk of losing their productivity under increasing rates of SLR (Donnelly and Bertness, 2001; Warren and Niering, 1993). The integrated hydrodynamic-marsh model (Hagen et al., 2013 & Alizad et al., 2015) uses a set of parameters and conditions to simulate tidal flow through the salt marsh of Plum Island Estuary, Massachusetts. The hydrodynamic model computes mean high water (MHW) and mean low water (MLW) and is coupled to the zero-dimensional Marsh Equilibrium Model (Morris et al. 2002) to estimate changes in biomass productivity and accretion. The coupled hydrodynamic-marsh model was used to examine the effects of different scenarios of SLR (Parris et al., 2012) on salt marsh productivity for the year 2100 in the Plum Island Estuary. In this particular study, responses of salt marsh production for different scenarios of SLR were compared. The study shows higher productivity of salt marsh under a low SLR scenario and lower productivity under the higher SLR. The study also demonstrates the migration of salt marshes under higher SLR scenarios. References: Alizad, K., S. C. Hagen, Morris, J.T., Bacopoulos, P., Bilskie, M.V., and John, F.W. 2015. A coupled, two-dimensional hydrodynamic-marsh model with biological feedback. Limnology and Oceanography, In review. Donnelly, J.P., and M.D. Bertness. 2001. Rapid shoreward encroachment of salt marsh cordgrass in response to accelerated sea-level rise. Proceedings of the National Academy of Sciences 98: 14218-14223.Hagen, S.C., J.T. Morris, P. Bacopoulos, and J. Weishampel. 2013. Sea-Level Rise Impact on a Salt Marsh System of the Lower St. Johns River. ASCE Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 139, No. 2, March/April 2013, pp. 118-125.Morris, J.T., P.V. Sundareshwar, C.T. Nietch, B. Kjerfve, and D.R. Cahoon. 2002. Responses

  1. Laws of physics help explain capillary non-perfusion in diabetic retinopathy.

    PubMed

    Stefánsson, E; Chan, Y K; Bek, T; Hardarson, S H; Wong, D; Wilson, D I

    2018-02-01

    The purpose is to use laws of physics to elucidate the mechanisms behind capillary non-perfusion in diabetic retinopathy. In diabetic retinopathy, loss of pericytes weakens capillary walls and the vessel dilates. A dilated capillary has reduced resistance to flow, therefore increased flow in that vessel and decreased in adjoining capillaries. A preferential shunt vessel is thus formed from the dilated capillary and the adjacent capillaries become non-perfused. We apply the laws of Laplace and Hagen-Poiseuille to better understand the phenomena that lead to capillary non-perfusion. These laws of physics can give a foundation for physical or mathematical models to further elucidate this field of study. The law of Laplace predicts that a weaker vessel wall will dilate, assuming constant transmural pressure. The Hagen-Poiseuille equation for flow and the Ostwald-de Waele relationship for viscosity predict that a dilated vessel will receive a higher portion of the fluid flow than the adjoining capillaries. Viscosity will decrease in the dilated vessel, furthering the imbalance and resulting in a patch of non-perfused capillaries next to the dilated 'preferential' shunt vessel. Physical principles support or inspire novel hypotheses to explain poorly understood phenomena in ophthalmology. This thesis of pericyte death and capillary remodelling, which was first proposed by Cogan and Kuwabara, already agrees with histological and angiographical observations in diabetic retinopathy. We have shown that it is also supported by classical laws of physics.

  2. William Herschel's 'Hole in the Sky' and the discovery of dark nebulae

    NASA Astrophysics Data System (ADS)

    Steinicke, Wolfgang

    2016-12-01

    In 1785 William Herschel published a paper in the Philosophical Transactions containing the remarkable section "An opening or hole". It describes an unusual vacant place in Scorpius. This matter falls into oblivion until Caroline Herschel initiated a correspondence with her nephew John in 1833. It contains Herschel's spectacular words "Hier ist wahrhaftig ein Loch im Himmel" ("Here truly is a hole in the sky"). About a hundred years later, Johann Georg Hagen, Director of the Vatican Observatory, presented a spectacular candidate for the 'hole', discovered in 1857 by Angelo Secchi in Sagittarius and later catalogued by Edward E. Barnard as the dark nebula B 86. Hagen's claim initiated a debate, mainly in the Journal of the British Astronomical Association, about the identity of Herschel's 'object'. Though things could be partly cleared up, unjustified claims still remain. This is mainly due to the fact that original sources were not consulted. A comprehensive study of the curious 'hole' is presented here. It covers major parts of the epochal astronomical work of William, Caroline and John Herschel. This includes a general study of 'vacant places', found by William Herschel and others, and the speculations about their nature, eventually leading to the finding that dark nebulae are due to absorbing interstellar matter. Some of the 'vacant places' could be identified in catalogues of dark nebulae and this leads to a 'Herschel Catalogue of Dark Nebulae' - the first historic catalogue of its kind.

  3. Subterranean termite open-air foraging and tolerance to desiccation: Comparative water relation of two sympatric Macrotermes spp. (Blattodea: Termitidae).

    PubMed

    Hu, Jian; Neoh, Kok-Boon; Appel, Arthur G; Lee, Chow-Yang

    2012-02-01

    The foraging patterns of termites are strongly related to physiological limits in overcoming desiccation stress. In this study, we examined moisture preferences and physiological characteristics of Macrotermes carbonarius (Hagen) and M. gilvus (Hagen) as both exhibit conspicuous patterns of foraging activity. Despite both species showing no significant differences in calculated cuticular permeability, and percentage of total body water, they differed greatly in rate of water loss and surface area to volume ratio. For example, M. carbonarius which had a lower surface area to volume ratio (29.26-53.66) showed lower rate of water loss and percentage of total body water loss. This also resulted in higher LT(50) when exposed to extreme conditions (≈2% RH). However, contrasting observations were made in M. gilvus that has smaller size with higher surface area to volume ratio of 40.28-69.75. It is likely that the standard equation for calculating insect surface areas is inadequate for these termite species. The trend was further supported by the result of a moisture preference bioassay that indicated M. carbonarius had a broader range of moisture preference (between 5% and 20%) than M. gilvus which had a relatively narrow moisture preference (only 20%). These results explain why M. carbonarius can tolerate desiccation stress for a longer period foraging above-ground in the open air; while M. gilvus only forages below ground or concealed within foraging mud tubes. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Artificial Icing Test, Utility Tactical Transport Aircraft System (UTTAS), Boeing Vertol YUH-61A Helicopter

    DTIC Science & Technology

    1977-01-01

    FOR OFFIC!AL USE ONLY VTT 0ff4 -40. -26-: a 20 TEMPATURE (-Q FIGUR~E t:. VMRATIOI4 (W THEMMONMIC FUNCTIOUt WITfLt -EA~UrT IOMMI4MTSRS- SOMiRE; jym...JOHN F. HAGEN MAJ, FA US ARMY JAMES C. O’CONNOR PROJECT OFFICER/PILOT CPT, CE US ARMY EDWARD J. TAVARES PROJECT PILOT CPT, TC US ARMY PROJECT...is no longer needed. Do not return it to the originator. TRADE NAMES The use of trade names in this report does not constitute an official endorsement

  5. Non-Grey Radiation Modeling using Thermal Desktop/Sindaworks TFAWS06-1009

    NASA Technical Reports Server (NTRS)

    Anderson, Kevin R.; Paine, Chris

    2006-01-01

    This paper provides an overview of the non-grey radiation modeling capabilities of Cullimore and Ring's Thermal Desktop(Registered TradeMark) Version 4.8 SindaWorks software. The non-grey radiation analysis theory implemented by Sindaworks and the methodology used by the software are outlined. Representative results from a parametric trade study of a radiation shield comprised of a series of v-grooved shaped deployable panels is used to illustrate the capabilities of the SindaWorks non-grey radiation thermal analysis software using emissivities with temperature and wavelength dependency modeled via a Hagen-Rubens relationship.

  6. Incomplete Co-cladogenesis Between Zootermopsis Termites and Their Associated Protists.

    PubMed

    Taerum, Stephen J; De Martini, Francesca; Liebig, Jürgen; Gile, Gillian H

    2018-02-08

    Coevolution is a major driver of speciation in many host-associated symbionts. In the termite-protist digestive symbiosis, the protists are vertically inherited by anal feeding among nest mates. Lower termites (all termite families except Termitidae) and their symbionts have broadly co-diversified over ~170 million yr. However, this inference is based mainly on the restricted distribution of certain protist genera to certain termite families. With the exception of one study, which demonstrated congruent phylogenies for the protist Pseudotrichonympha and its Rhinotermitidae hosts, coevolution in this symbiosis has not been investigated with molecular methods. Here we have characterized the hindgut symbiotic protists (Phylum Parabasalia) across the genus Zootermopsis (Archotermopsidae) using single cell isolation, molecular phylogenetics, and high-throughput amplicon sequencing. We report that the deepest divergence in the Zootermopsis phylogeny (Zootermopsis laticeps [Banks; Isoptera: Termopsidae]) corresponds with a divergence in three of the hindgut protist species. However, the crown Zootermopsis taxa (Zootermopsis angusticollis [Hagen; Isoptera: Termopsidae], Z. nevadensis nevadensis [Hagen; Isoptera: Termopsidae], and Z. nevadensis nuttingi [Haverty & Thorne; Isoptera: Termopsidae]) share the same protist species, with no evidence of co-speciation under our methods. We interpret this pattern as incomplete co-cladogenesis, though the possibility of symbiont exchange cannot be entirely ruled out. This is the first molecular evidence that identical communities of termite-associated protist species can inhabit multiple distinct host species. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Toxicity of Thiamethoxam Against Philippine Subterranean Termites

    PubMed Central

    Acda, Menandro N.

    2007-01-01

    Thiamethoxam (ACTARA® 25WG) was evaluated for its termiticidal properties against three species of economically important subterranean termites (Isoptera: Termitidae) in the Philippines: Nasutitermes luzonicus Oshima, Macrotermes gilvus Hagen, and Microcerotermes losbanosensis Oshima. Results of the study indicated that exposure to soil or ingestion of paper treated with thiamethoxam at concentration above 0.41 ppm may provide an adequate chemical barrier or induce high mortality against N. luzonicus, M. gilvus and M. losbanosensis after 5–9 days. Feeding bioassays showed that thiamethoxam was not repellent to M. gilvus and M. losbanosensis but had an anti-feeding effect on N. luzonicus. PMID:20302537

  8. The history and physics of heliox.

    PubMed

    Hess, Dean R; Fink, James B; Venkataraman, Shekhar T; Kim, In K; Myers, Timothy R; Tano, Benoit D

    2006-06-01

    Since the discovery of helium in 1868, it has found numerous applications in industry and medicine. Its low density makes helium potentially valuable in respiratory care applications, to reduce work of breathing, improve distribution of ventilation, reduce minute volume requirement, and improve aerosol delivery. This review includes a brief history of the use of heliox (a mixture of helium and oxygen) and addresses issues related to the physics of gas flow when heliox is used. Specifically covered are the Hagen-Poiseuille equation, laminar versus turbulent flow, the Reynolds number, orifice flow, Bernoulli's principle, Graham's law, wave speed, and thermal conductivity.

  9. Making Meaning of von Hagens' Body Worlds: Towards an Interdisciplinary Approach to Science Exhibitions

    NASA Astrophysics Data System (ADS)

    Dubek, Michelle Melodie

    Body Worlds is a traveling exhibition of plastinated human cadavers that offers the general public an opportunity to experience the human body in a unique way. It has been met with controversy and awe; public reactions and responses have been mixed. This case study research explored visitor responses to this controversial science exhibition, and examined the meaning visitors made of their experience. Specifically, the following research questions directed this study: Within the context of the Body Worlds exhibition: (a) What meaning did visitors make and how did they respond to the exhibits? (b) What tensions and issues arose for visitors? and (c) What did this type of exhibition convey about the changing role of science centres and the nature of their exhibitions? The primary sources of data for this study were 46 semi-structured interviews with visitors to the exhibition, observation notes, and 10 comment books including approximately 20 000 comments. Data suggested that the personal, physical, and sociocultural contexts (Falk & Dierking, 2000) contributed to visitor meaning meaning-making. The use of plastinated human cadavers within this exhibition raised ethical and moral questions and controversies about body procurement, use of human cadavers in display, representations of the bodies, and issues related to the sanctity of life. The tensions and issues identified by visitors demonstrated that messages (intended or unintended) located within Body Worlds were critically examined by visitors and called into question. Finally, data from this study suggested that an interdisciplinary approach to the presentation of science served to enhance accessibility for the viewer. This exhibition demonstrated that visitors responded positively and made personal connections when the arts, spirituality, edutainment, issues, and a combination of historical and contemporary museum practices were used to present science.

  10. Simple model of foam drainage

    NASA Astrophysics Data System (ADS)

    Fortes, M. A.; Coughlan, S.

    1994-10-01

    A simple model of foam drainage is introduced in which the Plateau borders and quadruple junctions are identified with pools that discharge through channels to pools underneath. The flow is driven by gravity and there are friction losses in the exhausting channels. The equation of Bernoulli combined with the Hagen-Poiseuille equation is applied to describe the flow. The area of the cross section of the exhausting channels can be taken as a constant or may vary during drainage. The predictions of the model are compared with standard drainage curves and with the results of a recently reported experiment in which additional liquid is supplied at the top of the froth.

  11. Light-weight plastination.

    PubMed

    Steinke, Hanno; Rabi, Suganthy; Saito, Toshiyuki; Sawutti, Alimjan; Miyaki, Takayoshi; Itoh, Masahiro; Spanel-Borowski, Katharina

    2008-11-20

    Plastination is an excellent technique which helps to keep the anatomical specimens in a dry, odourless state. Since the invention of plastination technique by von Hagens, research has been done to improve the quality of plastinated specimens. In this paper, we have described a method of producing light-weight plastinated specimens using xylene along with silicone and in the final step, substitute xylene with air. The finished plastinated specimens were light-weight, dry, odourless and robust. This method requires less use of resin thus making the plastination technique more cost-effective. The light-weight specimens are easy to carry and can easily be used for teaching.

  12. Characteristics of nuclepore filters with large pore size—I. Physical properties

    NASA Astrophysics Data System (ADS)

    John, W.; Hering, S.; Reischl, G.; Sasaki, G.; Goren, S.

    Measurements of pore diameter, pore density and filter thickness have been made on Nuclepore filters of 5, 8 and 12 μm pore size. The areal distribution of the pores is random, as verified by total hole counts and by counts of overlapping holes. Filter thicknesses decrease with increasing pore diameter. The Hagen-Poiseuille formula accounts for less than half of the measured pressure drop across 12 μm pore size filters. A new calculation, including a term for the pressure drop external to the filter, accounts quantitatively for the observations. There are sufficient variations among filter batches to require knowledge of the filter parameters for each batch to ensure accurate measurements using these filters.

  13. Description of the female of Navicordulia aemulatrix Pinto & Lamas and additional notes on the male (Odonata: Corduliidae).

    PubMed

    Pinto, A P; Lamas, C J E

    2011-01-01

    The female of Navicordulia aemulatrix Pinto & Lamas is described and illustrated for the first time based on a single specimen from the same locality of the type series (state of Santa Catarina, [municipality of São Bento do Sul, 26°14'58"S, 49°22'59"W, railroad station] Rio Vermelho, 29.I.1952, in MZSP). In addition, further morphological notes for the male are provided based on three specimens collected at the type locality and at a new locality in the state of Santa Catarina (Timbó municipality). The pronotal process present in N. aemulatrix is re-evaluated and considered non-homologous to that found in Neocordulia setifera (Hagen in Selys) as previously suggested.

  14. Experiencing Body Worlds: voyeurism, education, or enlightenment?

    PubMed

    Moore, Charleen M; Brown, C Mackenzie

    2007-12-01

    Until the advent of plastinated cadavers, few outside the medical professions have had firsthand experience with human corpses. Such opportunities are now available at the Body Worlds exhibits of Gunther von Hagens. After an overview of these exhibits, we explore visitor responses as revealed in comment books available upon exiting the exhibit. Cultural, philosophical, and religious issues raised in the comments serve as a microcosm of society at large. The conclusion considers the challenge of such exhibits in introducing the public to science education, notes the image of the body as machine-so prevalent in the West-reflected in visitor comments, and finds hope that the exhibits promote, for many visitors, a sense of community among all humankind.

  15. KSC-2012-5575

    NASA Image and Video Library

    2012-09-20

    CAPE CANAVERAL, Fla. - NASA's Johnson Space Center Aerospace Engineer Jeff Hagen attaches a rotor to the top of a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

  16. KSC-2012-5579

    NASA Image and Video Library

    2012-09-20

    CAPE CANAVERAL, Fla. - NASA Aerospace Engineer Jeff Hagen prepares a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

  17. Ground-Truthing of Airborne LiDAR Using RTK-GPS Surveyed Data in Coastal Louisiana's Wetlands

    NASA Astrophysics Data System (ADS)

    Lauve, R. M.; Alizad, K.; Hagen, S. C.

    2017-12-01

    Airborne LiDAR (Light Detection and Ranging) data are used by engineers and scientists to create bare earth digital elevation models (DEM), which are essential to modeling complex coastal, ecological, and hydrological systems. However, acquiring accurate bare earth elevations in coastal wetlands is difficult due to the density of marsh grasses that prevent the sensors reflection off the true ground surface. Previous work by Medeiros et al. [2015] developed a technique to assess LiDAR error and adjust elevations according to marsh vegetation density and index. The aim of this study is the collection of ground truth points and the investigation on the range of potential errors found in existing LiDAR datasets within coastal Louisiana's wetlands. Survey grids were mapped out in an area dominated by Spartina alterniflora and a survey-grade Trimble Real Time Kinematic (RTK) GPS device was employed to measure bare earth ground elevations in the marsh system adjacent to Terrebonne Bay, LA. Elevations were obtained for 20 meter-spaced surveyed grid points and were used to generate a DEM. The comparison between LiDAR derived and surveyed data DEMs yield an average difference of 23 cm with a maximum difference of 68 cm. Considering the local tidal range of 45 cm, these differences can introduce substantial error when the DEM is used for ecological modeling [Alizad et al., 2016]. Results from this study will be further analyzed and implemented in order to adjust LiDAR-derived DEMs closer to their true elevation across Louisiana's coastal wetlands. ReferencesAlizad, K., S. C. Hagen, J. T. Morris, S. C. Medeiros, M. V. Bilskie, and J. F. Weishampel (2016), Coastal wetland response to sea-level rise in a fluvial estuarine system, Earth's Future, 4(11), 483-497, 10.1002/2016EF000385. Medeiros, S., S. Hagen, J. Weishampel, and J. Angelo (2015), Adjusting Lidar-Derived Digital Terrain Models in Coastal Marshes Based on Estimated Aboveground Biomass Density, Remote Sensing, 7

  18. Comprehensive theory of the Deans' switch as a variable flow splitter: fluid mechanics, mass balance, and system behavior.

    PubMed

    Boeker, Peter; Leppert, Jan; Mysliwietz, Bodo; Lammers, Peter Schulze

    2013-10-01

    The Deans' switch is an effluent switching device based on controlling flows of carrier gas instead of mechanical valves in the analytical flow path. This technique offers high inertness and a wear-free operation. Recently new monolithic microfluidic devices have become available. In these devices the whole flow system is integrated into a small metal device with low thermal mass and leak-tight connections. In contrast to a mechanical valve-based system, a flow-controlled system is more difficult to calculate. Usually the Deans' switch is used to switch one inlet to one of two outlets, by means of two auxiliary flows. However, the Deans' switch can also be used to deliver the GC effluent with a specific split ratio to both outlets. The calculation of the split ratio of the inlet flow to the two outlets is challenging because of the asymmetries of the flow resistances. This is especially the case, if one of the outlets is a vacuum device, such as a mass spectrometer, and the other an atmospheric detector, e.g. a flame ionization detector (FID) or an olfactory (sniffing) port. The capillary flows in gas chromatography are calculated with the Hagen-Poiseuille equation of the laminar, isothermal and compressible flow in circular tubes. The flow resistances in the new microfluidic devices have to be calculated with the corresponding equation for rectangular cross-section microchannels. The Hagen-Poiseuille equation underestimates the flow to a vacuum outlet. A corrected equation originating from the theory of rarefied flows is presented. The calculation of pressures and flows of a Deans' switch based chromatographic system is done by the solution of mass balances. A specific challenge is the consideration of the antidiffusion resistor between the two auxiliary gas lines of the Deans' switch. A full solution for the calculation of the Deans' switch including this restrictor is presented. Results from validation measurements are in good accordance with the developed

  19. KSC-2012-5578

    NASA Image and Video Library

    2012-09-20

    CAPE CANAVERAL, Fla. - Astronauts Mike Fossum and Cady Coleman, both in blue flight suits, listen as NASA's Johnson Space Center Aerospace Engineer Jeff Hagen explains the rotor mechanism for a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

  20. KSC-2012-5574

    NASA Image and Video Library

    2012-09-20

    CAPE CANAVERAL, Fla. - NASA's Johnson Space Center Aerospace Engineer Jeff Hagen, left, and engineering intern Emmanuel Nyangweso attach rotors to the top of a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

  1. ThunderSTORM: a comprehensive ImageJ plug-in for PALM and STORM data analysis and super-resolution imaging

    PubMed Central

    Ovesný, Martin; Křížek, Pavel; Borkovec, Josef; Švindrych, Zdeněk; Hagen, Guy M.

    2014-01-01

    Summary: ThunderSTORM is an open-source, interactive and modular plug-in for ImageJ designed for automated processing, analysis and visualization of data acquired by single-molecule localization microscopy methods such as photo-activated localization microscopy and stochastic optical reconstruction microscopy. ThunderSTORM offers an extensive collection of processing and post-processing methods so that users can easily adapt the process of analysis to their data. ThunderSTORM also offers a set of tools for creation of simulated data and quantitative performance evaluation of localization algorithms using Monte Carlo simulations. Availability and implementation: ThunderSTORM and the online documentation are both freely accessible at https://code.google.com/p/thunder-storm/ Contact: guy.hagen@lf1.cuni.cz Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24771516

  2. A Study in Lyman-Alpha

    NASA Astrophysics Data System (ADS)

    Hagen, Alex

    This thesis concentrates on the physical and morphological properties of galaxies via image analysis and spectral energy distribution fitting. My research primarily focuses on Lyman-alpha emitting galaxies (LAEs) at z 2, but to place the investigations in context, comparison samples of galaxies are also used. These galaxies present the opportunity to study formation and evolution of low-mass galaxies at this redshift, which is extremely difficult using continuum selection methods. Chapter 1 gives an introduction to LAEs and puts them in the context of galaxy formation and evolution. Chapter 2 was originally published as Hagen et al. (2014), which studied the physical properties of LAEs at 1.9 < z < 3.5 from the HETDEX Pilot Survey (Adams et al. 2011; Blanc et al. 2011). This paper found that LAEs span almost a three dex range in stellar mass and could be simply drawn for the star-forming galaxy mass function. We also found that, while most LAEs are dust poor, there were some objects that weren't. The Lyman-alpha photons seem to experience the same dust opacity as the UV continuum, suggesting that in these galaxies Lyman-alpha does not undergo significant scattering before escaping. This result, when matched with radiative transfer simulations, will help to constrain how Lyman-alpha escapes galaxies. Chapter 3, originally published as Hagen et al. (2016), describes research that studies how Lyman-alpha emitters are drawn from star-forming galaxies. This work used galaxies identified via their optical emission lines (oELGs) as a comparison sample (Zeimann et al. 2015a). These oELGs have a mass range similar to LAEs and are an excellent comparison sample to LAEs. Previous comparison samples, such as LBGs, are two dex more massive than LAEs and thus do not represent galaxies in the same evolutionary state as LAEs. We compared ten physical and morphological properties between Lyman-alpha and non-Lyman-alpha emitting galaxies and found no statistically significant

  3. Predation and behavioral changes in the neotropical lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) exposed to lambda-cyhalothrin.

    PubMed

    Luna, René Fernando; Bestete, Luziani Rezende; Torres, Jorge Braz; da Silva-Torres, Christian Sherley Araújo

    2018-05-24

    Pyrethroid insecticides are widely recommended against various defoliating pest species, but usually lack efficacy against sucking pests such as aphids, which are preferred prey of lacewing larvae. Interaction of pyrethroids and lacewings are likely to occur in fields infested by both defoliating and sap-sucking pests and should provide a complementary control. Therefore, our study aimed to estimate dose-mortality curves and behavioral changes by Chrysoperla externa exposed to lambda-cyhalothrin. We tested the susceptibility of two populations from different locations and insecticide history exposure through topical application. Based on the LD 50 -calculated, the population exhibiting the greater LD 50 was exposed to resistance enhancement (Sel) by treating larvae once for seven successive generations. The population with lower LD 50 was kept without selection (Nsel). Subsequently, walking, predation and oviposition behavioral after exposure to dried insecticide residues were investigated. After seven generations with insecticide selection, the resistance rations between Sel and Nsel populations were 5.85- and 9.37-fold higher for larvae and 3.38- and 2.75-fold higher for adults, respectively. Selected females caged in partially treated arenas laid similar eggs number on both treated and untreated surfaces, while Nsel females laid fewer eggs on treated surfaces. Insecticide repellency was not observed in either population, although irritability was observed for Nsel larvae. Selected larvae confined on fully and partially treated surfaces walked further, for a longer time, and with greater speeds compared to Nsel larvae. Furthermore, Sel and Nsel larvae had reduced predation rates when confined on treated surfaces, and Nsel larvae consumed less prey than Sel larvae. Results indicate changes in susceptibility, behavior, and predation rate of C. externa following exposure to lambda-cyhalothrin.

  4. Management of cerebral palsy varies by healthcare region.

    PubMed

    Rackauskaite, Gija; Uldall, Peter W; Bech, Bodil H; Østergaard, John R

    2015-11-01

    Cerebral palsy (CP) is the most common type of motor disability in childhood. The aim of the present paper was to describe regional differences in the management of CP in school-aged children in Denmark. This was a cross-sectional study based on the Danish Cerebral Palsy Registry. The parents of 462 children answered a questionnaire about their child's treatment and the family's characteristics. Descriptive and logistic regression analyses were performed for every treatment modality, stratified by the Gross Motor Function Classification System (GMFCS) level and adjusted for family and child characteristics. Significant regional differences were found regarding the provision of occupational therapy at all GMFCS levels, speech therapy at GMFCS levels II-V and orthopaedic surgery at GMFCS levels I and III-V. No regional differences were observed in the frequency of physiotherapy. We found no regional differences in the severity of disability. Regional differences in the management of CP cannot be explained by social differences or differences in the severity of the disability. This study was funded by the Research Foundation from the Central Denmark Region and the Department of Clinical Medicine at Aarhus University Hospital, the Augustinus Foundation, the Bevica Foundation, the Dagmar Marshalls Foundation, the Ludvig and Sara Elsass Foundation, and the Civil Engineer Frode V. Nyegaard's and his Wife's Foundation. not relevant.

  5. KSC-2012-5577

    NASA Image and Video Library

    2012-09-20

    CAPE CANAVERAL, Fla. - Astronauts Mike Fossum and Cady Coleman, both in blue flight suits, look over the model capsule fit with rotor blades ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center Aerospace Engineer Jeff Hagen, right, fields questions about the project. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

  6. Statespace geometry of puff formation in pipe flow

    NASA Astrophysics Data System (ADS)

    Budanur, Nazmi Burak; Hof, Bjoern

    2017-11-01

    Localized patches of chaotically moving fluid known as puffs play a central role in the transition to turbulence in pipe flow. Puffs coexist with the laminar flow and their large-scale dynamics sets the critical Reynolds number: When the rate of puff splitting exceeds that of decaying, turbulence in a long pipe becomes sustained in a statistical sense. Since puffs appear despite the linear stability of the Hagen-Poiseuille flow, one expects them to emerge from the bifurcations of finite-amplitude solutions of Navier-Stokes equations. In numerical simulations of pipe flow, Avila et al., discovered a pair of streamwise localized relative periodic orbits, which are time-periodic solutions with spatial drifts. We combine symmetry reduction and Poincaré section methods to compute the unstable manifolds of these orbits, revealing statespace structures associated with different stages of puff formation.

  7. A review of the Nearctic genus Prostoia (Ricker) (Plecoptera, Nemouridae), with the description of a new species and a surprising range extension for P. hallasi Kondratieff & Kirchner.

    PubMed

    Grubbs, Scott A; Baumann, Richard W; DeWalt, R Edward; Tweddale, Tari

    2014-01-01

    The Nearctic genus Prostoia (Plecoptera: Nemouridae) is reviewed. Prostoia ozarkensis sp. n. is described from the male and female adult stages mainly from the Interior Highland region encompassing portions of Arkansas, Missouri, and Oklahoma. Prostoia ozarkensis sp. n. appears most closely related to two species, one distributed broadly across the western Nearctic region, P. besametsa (Ricker), and one found widely throughout the central and eastern Nearctic regions, P. completa (Walker). A surprising range extension is noted for P. hallasi Kondratieff & Kirchner, a species once known only from the Great Dismal Swamp, from small upland streams in southern Illinois. Additional new state records are documented for P. besametsa, P. completa, P. hallasi and P. similis (Hagen). Taxonomic keys to Prostoia males and females are provided, and scanning electron micrographs of adult genitalia of all species are given.

  8. Distribution Patterns of Ohio Stoneflies, with an Emphasis on Rare and Uncommon Species

    PubMed Central

    Grubbs, Scott A.; Pessimo, Massimo; DeWalt, R. Edward

    2013-01-01

    Presently, 102 stonefly species (Plecoptera) have been reported from Ohio. All 9 Nearctic families are represented. Over 90% of the fauna exhibit a combination of broad Nearctic-widespread, eastern Nearctic-widespread, Appalachian, and eastern Nearctic-unglaciated distributions. In contrast, only 2 species display a central Nearctic-Prairie distribution. Seven species of Perlidae are likely no longer present (Acroneuria evoluta Klapálek, A. perplexa Frison, Attaneuria ruralis (Hagen), and Neoperla mainensis Banks) or have experienced marked range reductions (Acroneuria abnormis (Newman), A. frisoni Stark and Brown, and A. filicis Frison). Another nearly 31% of the fauna (32 species) are rare, uncommon, or have highly-limited distributions within the state. Twelve of these species have Appalachian distributions, and an additional 8 have eastern Nearctic-unglaciated distributions. The distributional status for each of the 32 rare/uncommon species is discussed. PMID:24219390

  9. A review of the Nearctic genus Prostoia (Ricker) (Plecoptera, Nemouridae), with the description of a new species and a surprising range extension for P. hallasi Kondratieff & Kirchner

    PubMed Central

    Grubbs, Scott A.; Baumann, Richard W.; DeWalt, R. Edward; Tweddale, Tari

    2014-01-01

    Abstract The Nearctic genus Prostoia (Plecoptera: Nemouridae) is reviewed. Prostoia ozarkensis sp. n. is described from the male and female adult stages mainly from the Interior Highland region encompassing portions of Arkansas, Missouri, and Oklahoma. Prostoia ozarkensis sp. n. appears most closely related to two species, one distributed broadly across the western Nearctic region, P. besametsa (Ricker), and one found widely throughout the central and eastern Nearctic regions, P. completa (Walker). A surprising range extension is noted for P. hallasi Kondratieff & Kirchner, a species once known only from the Great Dismal Swamp, from small upland streams in southern Illinois. Additional new state records are documented for P. besametsa, P. completa, P. hallasi and P. similis (Hagen). Taxonomic keys to Prostoia males and females are provided, and scanning electron micrographs of adult genitalia of all species are given. PMID:24843258

  10. a Fractal Permeability Model Coupling Boundary-Layer Effect for Tight Oil Reservoirs

    NASA Astrophysics Data System (ADS)

    Wang, Fuyong; Liu, Zhichao; Jiao, Liang; Wang, Congle; Guo, Hu

    A fractal permeability model coupling non-flowing boundary-layer effect for tight oil reservoirs was proposed. Firstly, pore structures of tight formations were characterized with fractal theory. Then, with the empirical equation of boundary-layer thickness, Hagen-Poiseuille equation and fractal theory, a fractal torturous capillary tube model coupled with boundary-layer effect was developed, and verified with experimental data. Finally, the parameters influencing effective liquid permeability were quantitatively investigated. The research results show that effective liquid permeability of tight formations is not only decided by pore structures, but also affected by boundary-layer distributions, and effective liquid permeability is the function of fluid type, fluid viscosity, pressure gradient, fractal dimension, tortuosity fractal dimension, minimum pore radius and maximum pore radius. For the tight formations dominated with nanoscale pores, boundary-layer effect can significantly reduce effective liquid permeability, especially under low pressure gradient.

  11. Sensitivity of Estuaries to Coastal Morphological Change Induced by Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Alizad, K.; Hagen, S. C.; Bilskie, M. V.; Mariotti, G.

    2017-12-01

    Coastal wetlands play a critical role by providing food and habitat for a variety of species and by dissipating wave and storm surge. These regions are also vulnerable to climate change and specifically rising sea levels. Projections show that coastal marshes across the Northern Gulf of Mexico are threatened by a higher risk of losing their productivity through increased inundation depth and time [Alizad et al., 2016a]. Individual estuaries will respond differently to stressors based on local conditions such as tidal range, creek geometry, and sediment sources, among others. In addition, morphological changes in estuaries are functions of both physical processes such as hydrodynamics and wind waves as well as biological mechanisms. To investigate the sensitivity of storm surge to bio-geomorphological changes associated with climate change within an estuary, the Hydro-MEM model [Alizad et al., 2016b] and first-order bathymetric changes were applied for a set of sea level rise (SLR) scenarios. Morphologic change in the form of marsh platform accretion and enhanced bay bathymetry through time was employed in an ADvanced CIRCulation (ADCIRC) shallow-water equation model. The model was used to run synthetic storm simulations for an intermediate-low (0.5 m), intermediate-high (1.2 m), and high (2.0 m) SLR scenarios in Grand Bay, MS (marine dominated) and Weeks Bay, AL (mixed) estuaries. Results including with and without morphologic changes applied will be discussed. Future steps for incorporating morphological effects including channel widening and wave erosion processes into the Hydro-MEM model is to couple morphologic and hydrodynamic models [Mariotti and Canestrelli, 2017] in the Hydro-MEM time step framework. ReferencesAlizad, K., S. C. Hagen, J. T. Morris, S. C. Medeiros, M. V. Bilskie, and J. F. Weishampel (2016a), Coastal wetland response to sea-level rise in a fluvial estuarine system, Earth's Future, 4(11), 483-497. Alizad, K., S. C. Hagen, J. T. Morris, P

  12. Development of a flow controller for long-term sampling of gases and vapors using evacuated canisters.

    PubMed

    Rossner, Alan; Farant, Jean Pierre; Simon, Philippe; Wick, David P

    2002-11-15

    Anthropogenic activities contribute to the release of a wide variety of volatile organic compounds (VOC) into microenvironments. Developing and implementing new air sampling technologies that allow for the characterization of exposures to VOC can be useful for evaluating environmental and health concerns arising from such occurrences. A novel air sampler based on the use of a capillary flow controller connected to evacuated canisters (300 mL, 1 and 6 L) was designed and tested. The capillary tube, used to control the flow of air, is a variation on a sharp-edge orifice flow controller. It essentially controls the velocity of the fluid (air) as a function of the properties of the fluid, tube diameter and length. A model to predict flow rate in this dynamic system was developed. The mathematical model presented here was developed using the Hagen-Poiseuille equation and the ideal gas law to predict flow into the canisters used to sample for long periods of time. The Hagen-Poiseuille equation shows the relationship between flow rate, pressure gradient, capillary resistance, fluid viscosity, capillary length and diameter. The flow rates evaluated were extremely low, ranging from 0.05 to 1 mL min(-1). The model was compared with experimental results and was shown to overestimate the flow rate. Empirical equations were developed to more accurately predict flow for the 300 mL, 1 and 6 L canisters used for sampling periods ranging from several hours to one month. The theoretical and observed flow rates for different capillary geometries were evaluated. Each capillary flow controller geometry that was tested was found to generate very reproducible results, RSD < 2%. Also, the empirical formulas developed to predict flow rate given a specified diameter and capillary length were found to predict flow rate within 6% of the experimental data. The samplers were exposed to a variety of airborne vapors that allowed for comparison of the effectiveness of capillary flow controllers to

  13. Facilitating consumer access to health information.

    PubMed

    Snowdon, Anne; Schnarr, Karin; Alessi, Charles

    2014-01-01

    The lead paper from Zelmer and Hagens details the substantive evolution occurring in health information technologies that has the potential to transform the relationship between consumers, health practitioners and health systems. In this commentary, the authors suggest that Canada is experiencing a shift in consumer behaviour toward a desire to actively manage one's health and wellness that is being facilitated through the advent of health applications on mobile and online technologies platforms. The result is that Canadians are now able to create personalized health solutions based on their individual health values and goals. However, before Canadians are able to derive a personal health benefit from these rapid changes in information technology, they require and are increasingly demanding greater real-time access to their own health information to better inform decision-making, as well as interoperability between their personal health tracking systems and those of their health practitioner team.

  14. Dynamics of the concentration of IAA and some of its conjugates during the induction of somatic embryogenesis in Coffea canephora

    PubMed Central

    Ayil-Gutiérrez, Benajmín; Galaz-Ávalos, Rosa María; Peña-Cabrera, Eduardo; Loyola-Vargas, Victor Manuel

    2013-01-01

    Most of the somatic embryogenesis (SE) process requires the presence, either before or during the embryogenic process, of at least one exogenous auxin. This exogenous auxin induces the presence of endogenous auxins, which appears to be essential for SE induction. We found that during the preincubation period of SE in Coffea canephora, there is an important increase in both free and conjugated indole-3-acetic acid (IAA), as well as indole-3-butyric acid. This increase is accompanied by an increase in the expression of YUCCA (CcYUC), TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (CcTAA1), and GRETCHEN HAGEN 3 (GH3) genes. On the other hand, most of the IAA compounds decreased during the induction of SE. The results presented in this research suggest that a balance between free IAA and its amide conjugates is necessary to allow the expression of SE-related genes. PMID:24299659

  15. Mass flow and velocity profiles in Neurospora hyphae: partial plug flow dominates intra-hyphal transport.

    PubMed

    Abadeh, Aryan; Lew, Roger R

    2013-11-01

    Movement of nuclei, mitochondria and vacuoles through hyphal trunks of Neurospora crassa were vector-mapped using fluorescent markers and green fluorescent protein tags. The vectorial movements of all three were strongly correlated, indicating the central role of mass (bulk) flow in cytoplasm movements in N. crassa. Profiles of velocity versus distance from the hyphal wall did not match the parabolic shape predicted by the ideal Hagen-Poiseuille model of flow at low Reynolds number. Instead, the profiles were flat, consistent with a model of partial plug flow due to the high concentration of organelles in the flowing cytosol. The intra-hyphal pressure gradients were manipulated by localized external osmotic treatments to demonstrate the dependence of velocity (and direction) on pressure gradients within the hyphae. The data support the concept that mass transport, driven by pressure gradients, dominates intra-hyphal transport. The transport occurs by partial plug flow due to the organelles in the cytosol.

  16. Investigation into the absorptivity change in metals with increased laser power

    NASA Astrophysics Data System (ADS)

    Blidegn, M. Sc. K.; Olsen, Flemming O.

    1997-04-01

    At first glance the low absorptivity of metals in the infrared (IR) makes the use of YAG or carbon-dioxide lasers in metal processing very inefficient. However, it has been demonstrated that the absorptivity can reach significantly higher levels during the high power laser interaction. An increase which cannot be explained by the increase in temperature only. The interaction between laser light and metals is a major physical phenomena in laser material processing and when modeling processes the Drude free electron model or simplifications, such as the Hagen-Rubens relation, have often been used. This paper discusses the need to extend the Drude model taking into account interband transitions and anormal skin effect at low light intensities and a multiphoton absorption model in order to describe the increase in the absorptivity at high intensities. The model is compared with experimental results carried out at low power, and tested on experimental absorptivity measurements at high power YAG laser pulses, found in literature.

  17. Determination of the Accomodation Coefficient Using Vapor/Gas Bubble Dynamics in an Acoustic Field

    NASA Technical Reports Server (NTRS)

    Gumerov, Nail A.

    1999-01-01

    Non-equilibrium liquid/vapor phase transformations can occur in superheated or subcooled liquids in fast processes such as in evaporation in a vacuum, in processing of molten metals, and in vapor explosions. The rate at which such a phase transformation occurs, Xi, can be described by the Hertz-Knudsen-Langmuir formula. More than one century of the history of the accommodation coefficient measurements shows many problems with its determination. This coefficient depends on the temperature, is sensitive to the conditions at the interface, and is influenced by small amounts of impurities. Even recent measurements of the accommodation coefficient for water (Hagen et al, 1989) showed a huge variation in Beta from 1 for 1 micron droplets to 0.006 for 15 micron droplets. Moreover, existing measurement techniques for the accommodation coefficient are complex and expensive. Thus development of a relatively inexpensive and reliable technique for measurement of the accommodation coefficient for a wide range of substances and temperatures is of great practical importance.

  18. Ice nucleation rates near ˜225 K

    NASA Astrophysics Data System (ADS)

    Amaya, Andrew J.; Wyslouzil, Barbara E.

    2018-02-01

    We have measured the ice nucleation rates, Jice, in supercooled nano-droplets with radii ranging from 6.6 nm to 10 nm and droplet temperatures, Td, ranging from 225 K to 204 K. The initial temperature of the 10 nm water droplets is ˜250 K, i.e., well above the homogeneous nucleation temperature for micron sized water droplets, TH ˜235 K. The nucleation rates increase systematically from ˜1021 cm-3 s-1 to ˜1022 cm-3 s-1 in this temperature range, overlap with the nucleation rates of Manka et al. [Phys. Chem. Chem. Phys. 14, 4505 (2012)], and suggest that experiments with larger droplets would extrapolate smoothly the rates of Hagen et al. [J. Atmos. Sci. 38, 1236 (1981)]. The sharp corner in the rate data as temperature drops is, however, difficult to match with available theory even if we correct classical nucleation theory and the physical properties of water for the high internal pressure of the nanodroplets.

  19. Digital stereo-holographic microscopy for studying three-dimensional particle dynamics

    NASA Astrophysics Data System (ADS)

    Byeon, Hyeokjun; Go, Taesik; Lee, Sang Joon

    2018-06-01

    A digital stereo-holographic microscopy (DsHM) with two viewing angles is proposed to measure 3D information of microscale particles. This approach includes two volumetric recordings and numerical reconstruction, and it involves the combination of separately reconstructed holograms. The 3D positional information of a particle was determined by searching the center of the overlapped reconstructed volume. After confirming the proposed technique using static spherical particles, the 3D information of moving particles suspended in a Hagen-Poiseiulle flow was successfully obtained. Moreover, the 3D information of nonspherical particles, including ellipsoidal particles and red blood cells, were measured using the proposed technique. In addition to 3D positional information, the orientation and shape of the test samples were obtained from the plane images by slicing the overlapped volume perpendicular to the directions of the image recordings. This DsHM technique will be useful in analyzing the 3D dynamic behavior of various nonspherical particles, which cannot be measured by conventional digital holographic microscopy.

  20. Numerical simulation based on core analysis of a single fracture in an Enhanced Geothermal System

    NASA Astrophysics Data System (ADS)

    Jarrahi, Miad; Holländer, Hartmut

    2017-04-01

    The permeability of reservoirs is widely affected by the presence of fractures dispersed within them, as they form superior paths for fluid flow. Core analysis studies the fractures characteristics and explains the fluid-rock interactions to provide the information of permeability and saturation of a hydraulic fracturing reservoir or an enhanced geothermal system (EGS). This study conducted numerical simulations of a single fracture in a Granite core obtained from a depth of 1890 m in borehole EPS1 from Soultz-sous-Forêts, France. Blaisonneau et al. (2016) designed the apparatus to investigate the complex physical phenomena on this cylindrical sample. The method of the tests was to percolate a fluid through a natural fracture contained in a rock sample, under controlled thermo-hydro-mechanical conditions. A divergent radial flow within the fracture occurred due to the injection of fluid into the center of the fracture. The tests were performed within a containment cell with a normal stress of 2.6, 4.9, 7.2 and 9.4 MPa loading on the sample perpendicular to the fracture plane. This experiment was numerically performed to provide an efficient numerical method by modeling single phase flow in between the fracture walls. Detailed morphological features of the fracture such as tortuosity and roughness, were obtained by image processing. The results included injection pressure plots with respect to injection flow rate. Consequently, by utilizing Hagen-Poiseuille's cubic law, the equivalent hydraulic aperture size, of the fracture was derived. Then, as the sample is cylindrical, to modify the Hagen-Poiseuille's cubic law for circular parallel plates, the geometric relation was applied to obtain modified hydraulic aperture size. Finally, intrinsic permeability of the fracture under each mechanical normal stress was evaluated based on modified hydraulic aperture size. The results were presented in two different scenarios, before and after reactive percolation test, to

  1. Characterization of a custom-built RF coil for a high-resolution phase-contrast magnetic resonance velocimeter

    NASA Astrophysics Data System (ADS)

    Yang, Byungkuen; Cho, Jee-Hyun; Song, Simon

    2016-11-01

    For the use of clinical purpose magnetic resonance velocimeter (MRV) is a versatile flow visualization technique in that it allows opaque flow, complex geometry, no use of tracer particles and facile fast non-invasive measurements of 3 dimensional and 3 component velocity vectors. However, the spatial resolution of a commercial MR machine is lower than optics-based techniques like PIV. On the other hand, the use of MRV for clinical purposes like cardiovascular flow visualization requires accurate measurements or estimations on wall shear stress (WSS) with a high spatial resolution. We developed a custom-built solenoid RF coil for phase-contrast (PC) MRV to improve its resolution. We compared signal-to-noise ratio, WSS estimations, partial volume effects near wall between the custom RF coil and a commercial coil. Also, a Hagen-Poiseuille flow was analyzed with the custom RF coil. This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIP) (No. 2016R1A2B3009541).

  2. Prediction of the low-velocity distribution from the pore structure in simple porous media

    NASA Astrophysics Data System (ADS)

    de Anna, Pietro; Quaife, Bryan; Biros, George; Juanes, Ruben

    2017-12-01

    The macroscopic properties of fluid flow and transport through porous media are a direct consequence of the underlying pore structure. However, precise relations that characterize flow and transport from the statistics of pore-scale disorder have remained elusive. Here we investigate the relationship between pore structure and the resulting fluid flow and asymptotic transport behavior in two-dimensional geometries of nonoverlapping circular posts. We derive an analytical relationship between the pore throat size distribution fλ˜λ-β and the distribution of the low fluid velocities fu˜u-β /2 , based on a conceptual model of porelets (the flow established within each pore throat, here a Hagen-Poiseuille flow). Our model allows us to make predictions, within a continuous-time random-walk framework, for the asymptotic statistics of the spreading of fluid particles along their own trajectories. These predictions are confirmed by high-fidelity simulations of Stokes flow and advective transport. The proposed framework can be extended to other configurations which can be represented as a collection of known flow distributions.

  3. [Development of a glaucoma microstent with drainage into the suprachoroidal space: fluid mechanical model approach].

    PubMed

    Guthoff, R F; Schmidt, W; Buss, D; Schultze, C; Ruppin, U; Stachs, O; Sternberg, K; Klee, D; Chichkov, B; Schmitz, K-P

    2009-09-01

    The purpose of this study was to develop a microstent with valve function, which normalizes the intraocular pressure (IOP) and drains into the suprachoroidal space. In comparison to the subconjunctival space the suprachoroidal space is attributed with less fibroblast colonization and activity. Different glaucoma drainage devices were idealized as tubes and the flow rates were calculated according to Hagen-Poiseuille. The dimensions of the ideal glaucoma implant were modified with respect to an aqueous humor production of 2 microl/min and the different outflow pathways. Specific components of glaucoma drainage devices at the inlet and outlet were not included. The volume flow calculation of the tested glaucoma implants showed that the dimensions of all lumina were too large to prevent postoperative hypotension. A maximum inner tube diameter of 53 microm was calculated for drainage into the suprachoroidal space based on an intra-ocular pressure (IOP) of 20 mmHg. The glaucoma microstent has to guarantee an aqueous humor flow for physiological IOP. An increase of IOP has to be regulated to physiological pressure conditions by the microvalve.

  4. The Parasitoid, Verticia fasciventris Causes Morphological and Behavioral Changes in Infected Soldiers of the Fungus-Growing Termite, Macrotermes carbonarius

    PubMed Central

    Neoh, Kok-Boon; Lee, Chow-Yang

    2011-01-01

    The larval parasitoid Verticia fasciventris Malloch (Diptera: Calliphoridae) develops in the head of soldiers of the fungus-growing termite Macrotermes carbonarius (Hagen) (Isoptera: Termitidae). Morphological and behavioral changes in the host were evaluated and the termite castes and stages that were parasitized were identified. The larval emergence process is also described and possible mechanisms for the parasitoid fly's entry into the host body are discussed based on qualitative observations. Only a single larva per host was found. The mature larva pupated outside the host's body by exiting between the abdominal cerci. Parasitized soldiers possess a short and square-shaped head capsule, a pair of notably short mandibles, and a pair of 18-segmented antennae. Although parasitized soldiers were statistically less aggressive than healthy soldiers (P < 0.05), they expressed varying levels of aggression. Both minor and major soldiers can be parasitized and based on evidence from presoldiers, parasitization may begin during the precursor stages of soldiers. However, the stage at which parasitism first occurs has not been determined. PMID:21861651

  5. Boundary Layer Theory. Part 2; Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Schlichting, H.

    1949-01-01

    The flow laws of the actual flows at high Reynolds numbers differ considerably from those of the laminar flows treated in the preceding part. These actual flows show a special characteristic, denoted as turbulence. The character of a turbulent flow is most easily understood the case of the pipe flow. Consider the flow through a straight pipe of circular cross section and with a smooth wall. For laminar flow each fluid particle moves with uniform velocity along a rectilinear path. Because of viscosity, the velocity of the particles near the wall is smaller than that of the particles at the center. i% order to maintain the motion, a pressure decrease is required which, for laminar flow, is proportional to the first power of the mean flow velocity. Actually, however, one oberves that, for larger Reynolds numbers, the pressure drop increases almost with the square of the velocity and is very much larger then that given by the Hagen Poiseuille law. One may conclude that the actual flow is very different from that of the Poiseuille flow.

  6. Simulations of the Microcirculation in the Human Conjunctiva

    NASA Astrophysics Data System (ADS)

    Dow, William; Jacobitz, Frank; Chen, Peter

    2012-11-01

    The microcirculation in the conjunctiva of a healthy human subject is analyzed using a simulation approach. A comparison between healthy and diseased states may lead to early diagnosis for a variety of vascular related disorders. Previous work suggests that hypertension, arteriosclerosis, and diabetes mellitus have noticeable very early changes in the microvasculature (Davis and Landau, 1957; Ditzel, 1968; Kunitomo, 1974) and the vessels of the conjunctiva are specifically useful for this research because they can be studied non-invasively. The microcirculation in the conjunctiva has been documented over the course of disease treatments, providing both still images and video footage for information on vessel length, diameter, and connectivity as well as the direction of blood flow. The numerical method is based on a Hagen-Poiseuille balance in the microvessels and a sparse matrix solver is used to obtain the solution. The simulations use realistic vessel topology for the microvasculature, reconstructed from microscope images of tissue samples, and consider blood rheology as well as passive and active vessel properties.

  7. "Skinless wonders": Body Worlds and the Victorian freak show.

    PubMed

    Durbach, Nadja

    2014-01-01

    In 2002, Gunther von Hagens's display of plastinated corpses opened in London. Although the public was fascinated by Body Worlds, the media largely castigated the exhibition by dismissing it as a resuscitated Victorian freak show. By using the freak show analogy, the British press expressed their moral objection to this type of bodily display. But Body Worlds and nineteenth-century displays of human anomalies were linked in more complex and telling ways as both attempted to be simultaneously entertaining and educational. This essay argues that these forms of corporeal exhibitionism are both examples of the dynamic relationship between the popular and professional cultures of the body that we often erroneously think of as separate and discrete. By reading Body Worlds against the Victorian freak show, I seek to generate a fuller understanding of the historical and enduring relationship between exhibitionary culture and the discourses of science, and thus to argue that the scientific and the spectacular have been, and clearly continue to be, symbiotic modes of generating bodily knowledge.

  8. Hydrodynamics of steady state phloem transport with radial leakage of solute

    PubMed Central

    Cabrita, Paulo; Thorpe, Michael; Huber, Gregor

    2013-01-01

    Long-distance phloem transport occurs under a pressure gradient generated by the osmotic exchange of water associated with solute exchange in source and sink regions. But these exchanges also occur along the pathway, and yet their physiological role has almost been ignored in mathematical models of phloem transport. Here we present a steady state model for transport phloem which allows solute leakage, based on the Navier-Stokes and convection-diffusion equations which describe fluid motion rigorously. Sieve tube membrane permeability Ps for passive solute exchange (and correspondingly, membrane reflection coefficient) influenced model results strongly, and had to lie in the bottom range of the values reported for plant cells for the results to be realistic. This smaller permeability reflects the efficient specialization of sieve tube elements, minimizing any diffusive solute loss favored by the large concentration difference across the sieve tube membrane. We also found there can be a specific reflection coefficient for which pressure profiles and sap velocities can both be similar to those predicted by the Hagen-Poiseuille equation for a completely impermeable tube. PMID:24409189

  9. Hydrocarbon-water interactions during brine migration: Evidence from hydrocarbon inclusions in calcite cements from Danish North Sea oil fields

    USGS Publications Warehouse

    Jensenius, J.; Burruss, R.C.

    1990-01-01

    Crude oils in primary and secondary fluid inclusions in calcite from fractures in seven offshore oil fields associated with diapiric salt structures in the Danish sector of the North Sea were analyzed by capillary column gas chromatography and compared with crude oils produced from the same reservoirs. Oils from fluid inclusions in all fields show evidence of biodegradation (decreased n-C17/pristane and n-C18/phytane ratios and loss of n-C7, 2-methyl hexane, and 3-methyl hexane relative to methyl cyclohexane) and water washing (absence of benzene and depletion of toluene). Some oils in inclusions are extremely enriched in C6 and C7 cyclic alkanes suggesting that these samples contain hydrocarbons exsolved from ascending, hotter formation waters. Compared to inclusion oils the produced oils are less biodegraded, but are water washed, indicating that both types of oil interacted with large volumes of formation water. The carbon isotopic composition of the calcite host of the fluid inclusions in the Dagmar and Skjold fields is as light as -16.5%. PDB and the sulfur isotopic composition of pyrite in and adjacent to the calcite veins in the Skjold field is as light as -39.6%. CDT, indicating that biodegradation of the oils was a source of some of the carbon in the calcite and sulfate reduction was the source of sulfur for the pyrite. The evidence for microbial degradation of petroleum is consistent with present-day reservoir temperatures (65??-96??C) but is not consistent with previous estimates of the temperatures of calcite vein filling (95??-130??C) which are much higher than the temperatures of known occurrences of biodegraded oil. ?? 1990.

  10. Hydrocarbon-water interactions during brine migration: Evidence from hydrocarbon inclusions in calcite cements from Danish North Sea oil fields

    NASA Astrophysics Data System (ADS)

    Jensenius, Jørgen; Burruss, Robert C.

    1990-03-01

    Crude oils in primary and secondary fluid inclusions in calcite from fractures in seven offshore oil fields associated with diapiric salt structures in the Danish sector of the North Sea were analyzed by capillary column gas chromatography and compared with crude oils produced from the same reservoirs. Oils from fluid inclusions in all fields show evidence of biodegradation (decreased n- C17/pristane and n- C18/phytane ratios and loss of n-C 7, 2-methyl hexane, and 3-methyl hexane relative to methyl cyclohexane) and water washing (absence of benzene and depletion of toluene). Some oils in inclusions are extremely enriched in C 6 and C 7 cyclic alkanes suggesting that these samples contain hydrocarbons exsolved from ascending, hotter formation waters. Compared to inclusion oils the produced oils are less biodegraded, but are water washed, indicating that both types of oil interacted with large volumes of formation water. The carbon isotopic composition of the calcite host of the fluid inclusions in the Dagmar and Skjold fields is as light as -16.5%. PDB and the sulfur isotopic composition of pyrite in and adjacent to the calcite veins in the Skjold field is as light as -39.6%. CDT, indicating that biodegradation of the oils was a source of some of the carbon in the calcite and sulfate reduction was the source of sulfur for the pyrite. The evidence for microbial degradation of petroleum is consistent with present-day reservoir temperatures (65°-96°C) but is not consistent with previous estimates of the temperatures of calcite vein filling (95°-130°C) which are much higher than the temperatures of known occurrences of biodegraded oil.

  11. Experimental evidence for millisecond activation timescales using the Fast IN Chamber (FINCH) measurements

    NASA Astrophysics Data System (ADS)

    Bundke, U.; Jaenicke, R.; Klein, H.; Nillius, B.; Reimann, B.; Wetter, T.; Bingemer, H.

    2009-04-01

    Ice formation in clouds is a subject of great practical and fundamental importance since the occurrence of ice particle initializes dramatic changes in the microphysical structure of the cloud, which finally ends in the formation of precipitation. The initially step of ice formation is largely unknown. Homogenous nucleation of ice occurs only below -40 °C. If an ice nucleus (IN) is present, heterogeneous nucleation may occur at higher temperature. Here deposition freezing, condensation and immersion freezing as well as contact freezing are known. Also growth rates of ice particles are known as function of crystal surface properties, temperature and super saturation. Timescales for homogenous freezing activation in the order of 0.01 seconds and nucleation rates have been measured by Anderson et al. (1980) and Hagen et al., (1981) using their expansion cloud chamber. This contribution of deposition mode freezing measurements by the ice nucleus counter FINCH presents evidence that the activation timescale of this freezing mode is in the order of 1E-3 seconds. FINCH is an Ice Nucleus counter which activates IN in a supersaturated environment at freezing temperatures. The activation conditions are actively controlled by mixing three gas flows (aerosol, particle-free cold-dry and warm-humid flows).See Bundke et al. 2008 for details. In a special operation mode of FINCH we are able to produce a controlled peak super saturation in the order of 1 ms duration. For several test aerosols the results observed in this particular mode are comparable to normal mode operations, where the maximum super saturation remains for more than a second, thus leading to the conclusion that the time for activation is in the order of 1ms or less. References: R.J. Anderson et al, "A Study of Homogeneous Condensation Freezing Nucleation of Small Water Droplets in an Expansion Cloud Chamber, Journal of the Atmospheric Sciences, Vol. 37, 2508-2520, 1980 U.Bundke et al., "The fast Ice Nucleus

  12. Fresh from the Ornamental Garden: Hips of Selected Rose Cultivars Rich in Phytonutrients.

    PubMed

    Cunja, Vlasta; Mikulic-Petkovsek, Maja; Weber, Nika; Jakopic, Jerneja; Zupan, Anka; Veberic, Robert; Stampar, Franci; Schmitzer, Valentina

    2016-02-01

    Morphological parameters (size, weight, color), the content of sugars, organic acids, lycopene, β-carotene, and phenolics were determined in hips of Rosa canina (RCA), Rosa sweginzowii (RSW), Rosa rugosa (RUG), and selected ornamental Rosa cultivars Fru Dagmar Hastrup (FDH), Repandia (REP), Veilchenblau (RVB), Aloha (RAL), Bonica (BON), and Golden Gate (RGG). Although traditionally used RCA hips contained the highest amount of cyanidin-3-glucoside (83 μg/g DW) and were the reddest (h° = 17.5), they did not stand out in other analyzed parameters. RGG climber had the biggest hips (8.86 g), which also contained highest sugar levels (50.9 g/100 g DW). RAL stood out as the cultivar rich in organic acids (33.9 g/100 g DW), mainly because of high quinic acid content (17.6 g/100g DW). FDH and RSW hips were characterized by particularly high ascorbic acid levels (4325 mg/100 g DW and 4711 mg/100 g DW). Other ornamental cultivars contained low amounts of ascorbic acid compared to the analyzed species. The phenolic profile was species/cultivars-specific. The greatest diversity of phenolic compounds was detected in RUG and FDH hips (55 and 54 different tentatively identified compounds with HPLC/MS). Flavanols represented the main phenolic class in most of the investigated species/cultivars and RGG hips contained the highest amount of catechin and proanthocyandin derivatives (15855 μg/g DW). Altogether RAL hips contained the highest quantity of phenolics (44746 μg/g DW) mainly due to high levels of hydrolysable tannins compared to other species/cultivars. Although small, hips of BON and REP were most abundant regarding β-carotene and lycopene content, respectively. © 2016 Institute of Food Technologists®

  13. Fluid Dynamics of a Novel Micro-Fistula Implant for the Surgical Treatment of Glaucoma.

    PubMed

    Sheybani, Arsham; Reitsamer, Herbert; Ahmed, Iqbal Ike K

    2015-07-01

    The purpose of this study was to describe the fluidics of a novel non-valved glaucoma implant designed to prevent hypotony and compare the fluidics of this device with two commonly used non-valved glaucoma devices. The XEN 45 micro-fistula implant was designed to limit hypotony by virtue of its length and width according to the Hagen-Poiseuille equation. Flow testing was performed using a syringe pump and pressure transducer at multiple flow rates. The pressure differentials across the XEN implant, the Ex-Press implant, and 10 mm of silicone tubing from a Baerveldt implant at a physiologic flow rate (2.5 μL/min) were extrapolated. The XEN 45 achieved a steady-state pressure calculated at 7.56 mm Hg at 2.5 μL/min. At the same flow rate, the Ex-Press device and Baerveldt tubing reached steady-state pressures of 0.09 and 0.01 mm Hg, respectively. Under flow testing, the XEN micro-fistula implant was able to maintain backpressure above numerical hypotony levels without the use of complex valve systems. This is due to the XEN implant's design, derived from the principles that dictate Newtonian fluids.

  14. Divergence-free smoothing for MRV data on stenosed carotid artery phantom flows

    NASA Astrophysics Data System (ADS)

    Im, Chaehyuk; Ko, Seungbin; Song, Simon

    2017-11-01

    Magnetic Resonance Velocimetry (MRV) is a versatile technique for measuring flow velocity using an MRI machine. It is frequently used for visualization and analysis of blood flows. However, it is difficult to accurately estimate hemodynamics parameters like wall shear stress (WSS) and oscillatory shear index (OSI) due to its low spatial resolution and low signal-to-noise ratio. We suggest a divergence-free smoothing (DFS) method to correct the erroneous velocity vectors obtained with MRV and improve the estimation accuracy of those parameters. Unlike previous studies on DFS for a wall-free flow, we developed a house code to apply a DFS method to a wall-bounded flow. A Hagen-Poiseuille flow and stenosed carotid artery phantom flows were measured with MRV. Each of them was analyzed for validation of the DFS code and confirmation on the accuracy improvement of hemodynamic parameters. We will discuss the effects of DFS on the improvement of the estimation accuracy of velocity vectors, WSS, OSI and etc in detail This work was supported by the National Research Foundation of Korea(NRF) Grant funded by the Korea government(MSIP) (No. 2016R1A2B3009541).

  15. The integrated control concept and its relevance to current integrated pest management in California fresh market grapes.

    PubMed

    Bentley, Walter J

    2009-12-01

    The foundation of an integrated pest management program involves valid treatment thresholds, accurate and simple monitoring methods, effective natural controls, selective pesticides and trained individuals who can implement the concept. The Integrated Control Concept written by Stern, Smith, van den Bosch and Hagen elucidated each of these points in an alfalfa ecosystem. Alfalfa hay (Medicago sativa L.) has a low per acre value, requires little hand labor and is primarily marketed in the USA. In contrast, fresh market table grape (Vitis vinifera L.) has a high per acre value, requires frequent hand labor operations, suffers unacceptable cosmetic damage and is marketed throughout both the USA and the world. Each of the components of a working IPM program is present in table grape production. Marketing grapes to foreign countries presents special problems with pests considered invasive and where residue tolerances for some selective insecticides are lacking. However, fresh market grape farmers are still able to deal with these special problems and utilize an IPM program that has resulted in a 42% reduction in broad-spectrum insecticide use from 1995 to 2007. (c) 2009 Society of Chemical Industry.

  16. Drag Reduction Effect of BSA Monodispersed Solution in Microtube Flow

    NASA Astrophysics Data System (ADS)

    Kanda, Kensuke; Yang, Ming

    In recent biological and chemical analyses, microchips have attracted attention because of advantages such as high efficiency, small heat capacity, and high-speed reaction. Biochemical reagents and samples flow into the chips with the wall surface biologically or chemically modified. The mechanisms of the complex flow are not well-known. In this paper, the mechanisms are investigated using pressure drop measurements of the flow of BSA-(bovine serum albumin, protein generally used in analytical fields) dispersed solutions in microtubes with three kinds of surfaces: glass, PEEK (polyetheretherketone) and Hirec-X1 (a highly water-repellent agent, NTT-AT Co.), which have different properties. In the cases in which BSA solution flows on the Hirec-X1 and on the PEEK surface, results show reductions in the friction factor. On the other hand, in the case in which non BSA solution flow on any surface, results agree well with the Hagen-Poiseuille equation. Furthermore, reduction ratio in the friction factor depends on the concentration of BSA. These results imply that the interaction between the wall and the bio-molecules influences the behavior of the flow in microtubes.

  17. Simplified models of the symmetric single-pass parallel-plate counterflow heat exchanger: a tutorial.

    PubMed

    Pickard, William F; Abraham-Shrauner, Barbara

    2018-03-01

    The heat exchanger is important in practical thermal processes, especially those of (i) the molten-salt storage schemes, (ii) compressed air energy storage schemes and (iii) other load-shifting thermal storage presumed to undergird a Smart Grid. Such devices, although central to the utilization of energy from sustainable (but intermittent) renewable sources, will be unfamiliar to many scientists, who nevertheless need a working knowledge of them. This tutorial paper provides a largely self-contained conceptual introduction for such persons. It begins by modelling a novel quantized exchanger, impractical as a device, but useful for comprehending the underlying thermophysics. It then reviews the one-dimensional steady-state idealization which demonstrates that effectiveness of heat transfer increases monotonically with (device length)/(device throughput). Next, it presents a two-dimensional steady-state idealization for plug flow and from it derives a novel formula for effectiveness of transfer; this formula is then shown to agree well with a finite-difference time-domain solution of the two-dimensional idealization under Hagen-Poiseuille flow. These results are consistent with a conclusion that effectiveness of heat exchange can approach unity, but may involve unwelcome trade-offs among device cost, size and throughput.

  18. Physiology of transgenic mice with brown fat ablation: obesity is due to lowered body temperature.

    PubMed

    Klaus, S; Münzberg, H; Trüloff, C; Heldmaier, G

    1998-02-01

    We investigated the physiological basis for development of obesity in uncoupling protein-diphtheria toxin A chain (UCP-DTA) transgenic mice. In these mice the promoter of the brown adipose tissue (BAT)-specific UCP was used to drive expression of DTA, resulting in decreased BAT function and development of obesity and insulin resistance (Lowell, B. B., S. V. Susulic, A. Hamann, J. A. Lawitts, J. Himms-Hagen, B. B. Boyer, L. Kozak, and J. S. Flier. Nature 366: 740-742, 1994). In adult UCP-DTA mice, we measured food intake and food assimilation, locomotor activity, metabolic rate, and body temperature in comparison to control animals. No differences could be observed in food intake or assimilation and locomotor activity. Weight-specific metabolic rates at temperatures between 20 and 37 degrees C, however, were consistently lower in transgenic mice. Continuous telemetric recording of core body temperature showed that transgenic mice displayed a downshift in body temperature levels of approximately 0.9 degree C. In summary, we provide evidence that attenuated body temperature levels alone can be responsible for development of obesity and that BAT thermogenesis is a major determinant of body temperature levels in rodents.

  19. Simplified models of the symmetric single-pass parallel-plate counterflow heat exchanger: a tutorial

    NASA Astrophysics Data System (ADS)

    Pickard, William F.; Abraham-Shrauner, Barbara

    2018-03-01

    The heat exchanger is important in practical thermal processes, especially those of (i) the molten-salt storage schemes, (ii) compressed air energy storage schemes and (iii) other load-shifting thermal storage presumed to undergird a Smart Grid. Such devices, although central to the utilization of energy from sustainable (but intermittent) renewable sources, will be unfamiliar to many scientists, who nevertheless need a working knowledge of them. This tutorial paper provides a largely self-contained conceptual introduction for such persons. It begins by modelling a novel quantized exchanger,1 impractical as a device, but useful for comprehending the underlying thermophysics. It then reviews the one-dimensional steady-state idealization which demonstrates that effectiveness of heat transfer increases monotonically with (device length)/(device throughput). Next, it presents a two-dimensional steady-state idealization for plug flow and from it derives a novel formula for effectiveness of transfer; this formula is then shown to agree well with a finite-difference time-domain solution of the two-dimensional idealization under Hagen-Poiseuille flow. These results are consistent with a conclusion that effectiveness of heat exchange can approach unity, but may involve unwelcome trade-offs among device cost, size and throughput.

  20. Fully localised nonlinear energy growth optimals in pipe flow

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pringle, Chris C. T.; Willis, Ashley P.; Kerswell, Rich R.

    A new, fully localised, energy growth optimal is found over large times and in long pipe domains at a given mass flow rate. This optimal emerges at a threshold disturbance energy below which a nonlinear version of the known (streamwise-independent) linear optimal [P. J. Schmid and D. S. Henningson, “Optimal energy density growth in Hagen-Poiseuille flow,” J. Fluid Mech. 277, 192–225 (1994)] is selected and appears to remain the optimal up until the critical energy at which transition is triggered. The form of this optimal is similar to that found in short pipes [Pringle et al., “Minimal seeds for shearmore » flow turbulence: Using nonlinear transient growth to touch the edge of chaos,” J. Fluid Mech. 702, 415–443 (2012)], but now with full localisation in the streamwise direction. This fully localised optimal perturbation represents the best approximation yet of the minimal seed (the smallest perturbation which is arbitrarily close to states capable of triggering a turbulent episode) for “real” (laboratory) pipe flows. Dependence of the optimal with respect to several parameters has been computed and establishes that the structure is robust.« less

  1. Evaluation of fipronil and imidacloprid as bait active ingredients against fungus-growing termites (Blattodea: Termitidae: Macrotermitinae).

    PubMed

    Iqbal, N; Evans, T A

    2018-02-01

    Fungus-growing termites (Macrotermitinae) are important pests in tropical countries. They are difficult to control with existing baiting methods, as chitin synthesis inhibitors are not effectual as active ingredients. We tested two neurotoxins, fipronil and imidacloprid, as potential bait active ingredients against Macrotermes gilvus (Hagen) in Singapore. In laboratory bioassays, M. gilvus showed no preference for doses of 0-64 ppm fipronil, or for doses of 0-250 ppm imidacloprid, indicating no repellence. We tested each insecticide in toilet paper as a bait matrix in a field experiment. After 28 days, termites had eaten 5-13% of the fipronil treated toilet paper, abandoned bait and monitoring stations, contacted no new stations, and repaired poorly their experimentally damaged mounds. Termites ate no imidacloprid treated toilet paper, abandoned bait stations although contacted new stations, and repaired fully their damaged mounds. Termites ate 60-70% of the control toilet paper, remained in bait stations, and fully repaired damaged mounds. After 56 days, all five fipronil colonies were eliminated, whereas all of the imidacloprid and control colonies were healthy. The results suggest that fipronil could be an effective active ingredient in bait systems for fungus-growing termites in tropical countries.

  2. Species Diversity of Puerto Rican Heterotermes (Dictyoptera: Rhinotermitidae) Revealed by Phylogenetic Analyses of Two Mitochondrial Genes

    PubMed Central

    Jones, Susan C.; Jenkins, Tracie M.

    2016-01-01

    The goal of this study was to infer Heterotermes (Froggatt) (Dictyoptera: Rhinotermitidae) species diversity on the island of Puerto Rico from phylogenetic analyses of DNA sequence data from two mitochondrial genes, 16S rRNA and cytochrome oxidase II (COII). This termite genus is a structural pest known to be well adapted to arid environments in subtropical and tropical regions worldwide including Puerto Rico and many other Caribbean islands. Extensive sampling was accomplished across Puerto Rico, and phylogenetic analyses of individual gene sequences from these samples indicated robust datasets of congruent gene tree topologies showing three monophyletic groups: H. cardini (Snyder), H. convexinotatus (Snyder), and H. tenuis (Hagen). We found that H. cardini and H. convexinotatus were widespread in the arid coastal regions of Puerto Rico, whereas H. tenuis was uncommon and may represent a relatively new introduction. We found only H. convexinotatus on Culebra Island. We provide strong evidence that Puerto Rico may be linked to the Heterotermes in southern Florida, USA, since its GenBank 16S sequence was identical to that of seven Puerto Rican H. cardini sequences. Our study represents the first records of H. cardini from Puerto Rico and Grand Bahama.

  3. E12 sheet plastination: Techniques and applications.

    PubMed

    Ottone, Nicolas Ernesto; Baptista, Carlos A C; Latorre, Rafael; Bianchi, Homero Felipe; Del Sol, Mariano; Fuentes, Ramon

    2017-10-30

    Plastination is an anatomical technique that consists of replacing the liquids and fat of specimens by reactive polymers through forced impregnation in a vacuum. These are then polymerized to achieve the final result. E12 sheet plastination involves epoxy resin impregnation of thin (2-4 mm) and ultra-thin (<2 mm) tissue sheets, producing dry, transparent, odorless, non-toxic and long-lasting sheets. E12 sheet plastination techniques were reviewed using MEDLINE, EMBASE and SciELO databases, and manual searches. After searching, 616 records were found using the online and manual searches (MEDLINE, n: 207; EMBASE, n: 346; SciELO, n: 44; Manual search: 23). Finally, 96 records were included in this review (after duplicates and articles unrelated to the subject were excluded). The aim of this work was to review the E12 sheet plastination technique, searching for articles concerning views of it, identifying the different variants implemented by researchers since its creation by Gunther von Hagens, and to identify its applications from teaching and research in anatomy to morphological sciences. Clin. Anat., 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Carbon nanotube-based coatings to induce flow enhancement in hydrophilic nanopores

    NASA Astrophysics Data System (ADS)

    Wagemann, Enrique; Walther, J. H.; Zambrano, Harvey A.

    2016-11-01

    With the emergence of the field of nanofluidics, the transport of water in hydrophilic nanopores has attracted intensive research due to its many promising applications. Experiments and simulations have found that flow resistance in hydrophilic nanochannels is much higher than those in macrochannels. Indeed, this might be attributed to significant fluid adsorption on the channel walls and to the effect of the increased surface to volume ratio inherent to the nanoconfinement. Therefore, it is desirable to explore strategies for drag reduction in nanopores. Recently, studies have found that carbon nanotubes (CNTs) feature ultrafast water flow rates which result in flow enhancements of 1 to 5 orders of magnitude compared to Hagen-Poiseuille predictions. In the present study, CNT-based coatings are considered to induce water flow enhancement in silica nanopores with different radius. We conduct atomistic simulations of pressurized water flow inside tubular silica nanopores with and without inner coaxial carbon nanotubes. In particular, we compute water density and velocity profiles, flow enhancement and slip lengths to understand the drag reduction capabilities of single- and multi-walled carbon nanotubes implemented as coating material in silica nanopores. We wish to thank partial funding from CRHIAM and FONDECYT project 11130559, computational support from DTU and NLHPC (Chile).

  5. Perfusion pressure of a new cannulating fenestrated pedicle screw during cement augmentation.

    PubMed

    Wang, Zhirong; Zhang, Wen; Xu, Hao; Lu, Aiqing; Yang, Huilin; Luo, Zong-Ping

    2018-06-18

    Cannulating fenestrated pedicle screws are effective for fixating osteoporotic vertebrae. However, a major limitation is the excessive pressure required to inject a sufficient amount of cement into the vertebral body through the narrow hole of a pedicle screw. We have recently proposed a new cannulating fenestrated pedicle screw with a large hole diameter and a matched inner pin for screw-strength maintenance. Our purpose was to determine whether the new screw can significantly reduce bone-cement perfusion pressure during cement augmentation, METHODS: Two different methods were used to examine perfusion pressure. Hagen-Poisseuille's flow model in a tube was used to calculate pressure drop in the bone-cement channel. Experimentally, both Newtonian silicone oil and bone-cement (polymethyl methacrylate) were tested using a cement pusher through the cannulating screw at a constant rate of 2 ml/min. The internal hollow portion of the screw was the bottleneck of the perfusion, and the new design significantly reduced the perfusion pressure. Specifically, perfusion pressure dropped by 59% (P < 0.05) when diameter size was doubled. The new design effectively improved the application of bone-cement augmentation with the ease of bone-cement perfusion, thereby enhancing operational safety. Copyright © 2018. Published by Elsevier Ltd.

  6. Canonical Nonlinear Viscous Core Solution in pipe and elliptical geometry

    NASA Astrophysics Data System (ADS)

    Ozcakir, Ozge

    2016-11-01

    In an earlier paper (Ozcakir et al. (2016)), two new nonlinear traveling wave solutions were found with collapsing structure towards the center of the pipe as Reynolds number R -> ∞ , which were called Nonlinear Viscous Core (NVC) states. Asymptotic scaling arguments suggested that the NVC state collapse rate scales as R - 1 / 4 where axial, radial and azimuthal velocity perturbations from Hagen-Poiseuille flow scale as R - 1 / 2, R - 3 / 4 and R - 3 / 4 respectively, while (1 - c) = O (R - 1 / 2) where c is the traveling wave speed. The theoretical scaling results were roughly consistent with full Navier-Stokes numerical computations in the range 105 < R <106 . In the present paper, through numerical solutions, we show that the scaled parameter free canonical differential equations derived in Ozcakir et al. (2016) indeed has solution that satisfies requisite far-field conditions. We also show that these are in good agreement with full Navier-Stokes calculations in a larger R range than previously calculated (R upto 106). Further, we extend our study to NVC states for pipes with elliptical cross-section and identify similar canonical structure in these cases. National Science Foundation NSF-DMS-1515755, EPSRC Grant EP/1037948/1.

  7. [The tragic doubt].

    PubMed

    Musial, G

    2001-01-01

    Starting with two statements made by two great artists and witnesses of the XXth century - Joseph Brodsky and the Polish poet, Tadeusz Rozewicz - the author discusses the roots of our current moral crisis to which we ourselves bear witness: in the unchecked population explosion (Brodsky), and in the sinister legacy of World War II, the effects of which we witness on a daily basis (Rozewicz). The author recalls a third witness: Czeslaw Milosz, who wrote that the world's progress exhibits an inevitable tendency toward nihilism. In his discourse with the three statements mentioned, the author refers to certain XXth century intellectuals - Ortega y Gasset, Cardinal Joseph Ratzinger, Mircea Eliade, Herbert Read - who confirm and develop the thesis of man s spiritual fall and rejection of transcendence through technology. The author further illustrates his thesis with examples taken from the scientific research concerning IT, cloning, euthanasia, as well as from the world of the arts from the apocalyptic works of Hieronymous Bosch and Pieter Bruegel the Elder to the latest performers. He invokes a worldview which, by rejecting the metaphysics of man s birth, aging, and death, also rejects the judeo-christian taboo of the human body as a "dwelling place for the spirit" (porno festivals, exhibitions of human corpses by Prof. von Hagens in Germany).

  8. Crystal structure of an indole-3-acetic acid amido synthetase from grapevine involved in auxin homeostasis.

    PubMed

    Peat, Thomas S; Böttcher, Christine; Newman, Janet; Lucent, Del; Cowieson, Nathan; Davies, Christopher

    2012-11-01

    Auxins are important for plant growth and development, including the control of fruit ripening. Conjugation to amino acids by indole-3-acetic acid (IAA)-amido synthetases is an important part of auxin homeostasis. The structure of the auxin-conjugating Gretchen Hagen3-1 (GH3-1) enzyme from grapevine (Vitis vinifera), in complex with an inhibitor (adenosine-5'-[2-(1H-indol-3-yl)ethyl]phosphate), is presented. Comparison with a previously published benzoate-conjugating enzyme from Arabidopsis thaliana indicates that grapevine GH3-1 has a highly similar domain structure and also undergoes a large conformational change during catalysis. Mutational analyses and structural comparisons with other proteins have identified residues likely to be involved in acyl group, amino acid, and ATP substrate binding. Vv GH3-1 is a monomer in solution and requires magnesium ions solely for the adenlyation reaction. Modeling of IAA and two synthetic auxins, benzothiazole-2-oxyacetic acid (BTOA) and 1-naphthaleneacetic acid (NAA), into the active site indicates that NAA and BTOA are likely to be poor substrates for this enzyme, confirming previous enzyme kinetic studies. This suggests a reason for the increased effectiveness of NAA and BTOA as auxins in planta and provides a tool for designing new and effective auxins.

  9. Upstream dispersal of an invasive crayfish aided by a fish passage facility

    USGS Publications Warehouse

    Welsh, Stuart A.; Loughman, Zachary J.

    2015-01-01

    Fish passage facilities for reservoir dams have been used to restore habitat connectivity within riverine networks by allowing upstream passage for native species. These facilities may also support the spread of invasive species, an unintended consequence and potential downside of upstream passage structures. We documented dam passage of the invasive virile crayfish, Orconectes virilis (Hagen, 1870), at fish ladders designed for upstream passage of American eels, Anguilla rostrata (Lesueur, 1817), in the Shenandoah River drainage, USA. Ladder use and upstream passage of 11 virile crayfish occurred from 2007–2014 during periods of low river discharge (<30 m3s–1) and within a wide range of water temperatures from 9.0–28.6 °C. Virile crayfish that used the eel ladders were large adults with a mean carapace length and width of 48.0 mm and 24.1 mm, respectively. Our data demonstrated the use of species-specific fish ladders by a non-target non-native species, which has conservation and management implications for the spread of aquatic invasive species and upstream passage facilities. Specifically, managers should consider implementing long-term monitoring of fish passage facilities with emphasis on detection of invasive species, as well as methods to reduce or eliminate passage of invasive species. 

  10. Boys who pee the farthest have a large hollow head, a thin skin, and medium-size manhood

    NASA Astrophysics Data System (ADS)

    Attinger, Daniel; Lee, Vincent

    2016-11-01

    Following a recent trend of scientific studies on artwork, we study here the thermodynamics of a jetting thermometer made of ceramic, related to the Chinese tea culture. The thermometer represents a boy who "urinates" shortly after hot water is poured onto his head. Long jetting distance indicates if the water temperature is hot enough to brew tea. Here, a thermofluid model describes the jetting phenomenon of that pee-pee boy. The study demonstrates how thermal expansion of an interior air pocket causes jetting. The validity of assumptions underlying the Hagen-Poiseuille flow is discussed for urethra of finite length. A thermodynamic potential is shown to define maximum jetting velocity. Seven optimization criteria to maximize jetting distance are provided, including two dimensionless numbers. The dimensionless numbers are obtained by comparing the time scales of the internal pressure buildup due to heating, with that of pressure relief due to jetting. Optimization results show that longer jets are produced by large individuals, with low body mass index, with a boyhood of medium size inclined at an angle π/4. Analogies are drawn with pissing contests among humans and lobsters. The study ends by noting similitudes of working principle between that politically incorrect thermometer and Galileo Galilei's thermoscope.

  11. A comparison of two methods for measuring vessel length in woody plants.

    PubMed

    Pan, Ruihua; Geng, Jing; Cai, Jing; Tyree, Melvin T

    2015-12-01

    Vessel lengths are important to plant hydraulic studies, but are not often reported because of the time required to obtain measurements. This paper compares the fast dynamic method (air injection method) with the slower but traditional static method (rubber injection method). Our hypothesis was that the dynamic method should yield a larger mean vessel length than the static method. Vessel length was measured by both methods in current year stems of Acer, Populus, Vitis and Quercus representing short- to long-vessel species. The hypothesis was verified. The reason for the consistently larger values of vessel length is because the dynamic method measures air flow rates in cut open vessels. The Hagen-Poiseuille law predicts that the air flow rate should depend on the product of number of cut open vessels times the fourth power of vessel diameter. An argument is advanced that the dynamic method is more appropriate because it measures the length of the vessels that contribute most to hydraulic flow. If all vessels had the same vessel length distribution regardless of diameter, then both methods should yield the same average length. This supports the hypothesis that large-diameter vessels might be longer than short-diameter vessels in most species. © 2015 John Wiley & Sons Ltd.

  12. Discharge flow of a granular media from a silo: effect of the packing fraction and of the hopper angle

    NASA Astrophysics Data System (ADS)

    Benyamine, Mebirika; Aussillous, Pascale; Dalloz-Dubrujeaud, Blanche

    2017-06-01

    Silos are widely used in the industry. While empirical predictions of the flow rate, based on scaling laws, have existed for more than a century (Hagen 1852, translated in [1] - Beverloo et al. [2]), recent advances have be made on the understanding of the control parameters of the flow. In particular, using continuous modeling together with a mu(I) granular rheology seem to be successful in predicting the flow rate for large numbers of beads at the aperture (Staron et al.[3], [4]). Moreover Janda et al.[5] have shown that the packing fraction at the outlet plays an important role when the number of beads at the apeture decreases. Based on these considerations, we have studied experimentally the discharge flow of a granular media from a rectangular silo. We have varied two main parameters: the angle of the hopper, and the bulk packing fraction of the granular material by using bidisperse mixtures. We propose a simple physical model to describe the effect of these parameters, considering a continuous granular media with a dilatancy law at the outlet. This model predicts well the dependance of the flow rate on the hopper angle as well as the dependance of the flow rate on the fine mass fraction of a bidisperse mixture.

  13. Influence of environmental factors on activity patterns of Incisitermes minor (Isoptera: Kalotermitidae) in naturally infested logs.

    PubMed

    Lewis, Vernard R; Leighton, Shawn; Tabuchi, Robin; Baldwin, James A; Haverty, Michael I

    2013-02-01

    Acoustic emission (AE) activity patterns were measured from seven loquat [Eriobotrya japonica (Thunb.) Lindl.] logs, five containing live western drywood termite [Incisitermes minor (Hagen)] infestations, and two without an active drywood termite infestation. AE activity, as well as temperature, were monitored every 3 min under unrestricted ambient conditions in a small wooden building, under unrestricted ambient conditions but in constant darkness, or in a temperature-controlled cabined under constant darkness. Logs with active drywood termite infestations displayed similar diurnal cycles of AE activity that closely followed temperature with a peak of AE activity late in the afternoon (1700-1800 hours). When light was excluded from the building, a circadian pattern continued and apparently was driven by temperature. When the seven logs were kept at a relatively constant temperature (approximately 23 +/- 0.9 degrees C) and constant darkness, the pattern of activity was closely correlated with temperature, even with minimal changes in temperature. Temperature is the primary driver of activity of these drywood termites, but the effects are different when temperature is increasing or decreasing. At constant temperature, AE activity was highly correlated with the number of termites in the logs. The possible implications of these findings on our understanding of drywood termite biology and how this information may affect inspections and posttreatment evaluations are discussed.

  14. Arabidopsis thaliana GH3.5 acyl acid amido synthetase mediates metabolic crosstalk in auxin and salicylic acid homeostasis

    PubMed Central

    Westfall, Corey S.; Sherp, Ashley M.; Zubieta, Chloe; Alvarez, Sophie; Schraft, Evelyn; Marcellin, Romain; Ramirez, Loren; Jez, Joseph M.

    2016-01-01

    In Arabidopsis thaliana, the acyl acid amido synthetase Gretchen Hagen 3.5 (AtGH3.5) conjugates both indole-3-acetic acid (IAA) and salicylic acid (SA) to modulate auxin and pathogen response pathways. To understand the molecular basis for the activity of AtGH3.5, we determined the X-ray crystal structure of the enzyme in complex with IAA and AMP. Biochemical analysis demonstrates that the substrate preference of AtGH3.5 is wider than originally described and includes the natural auxin phenylacetic acid (PAA) and the potential SA precursor benzoic acid (BA). Residues that determine IAA versus BA substrate preference were identified. The dual functionality of AtGH3.5 is unique to this enzyme although multiple IAA-conjugating GH3 proteins share nearly identical acyl acid binding sites. In planta analysis of IAA, PAA, SA, and BA and their respective aspartyl conjugates were determined in wild-type and overexpressing lines of A. thaliana. This study suggests that AtGH3.5 conjugates auxins (i.e., IAA and PAA) and benzoates (i.e., SA and BA) to mediate crosstalk between different metabolic pathways, broadening the potential roles for GH3 acyl acid amido synthetases in plants. PMID:27849615

  15. Viscosity changes of riparian water controls diurnal fluctuations of stream-flow and DOC concentration

    NASA Astrophysics Data System (ADS)

    Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

    2015-04-01

    Diurnal fluctuations in stream-flow are commonly explained as being triggered by the daily evapotranspiration cycle in the riparian zone, leading to stream flow minima in the afternoon. While this trigger effect must necessarily be constrained by the extent of the growing season of vegetation, we here show evidence of daily stream flow maxima in the afternoon in a small headwater stream during the dormant season. We hypothesize that the afternoon maxima in stream flow are induced by viscosity changes of riparian water that is caused by diurnal temperature variations of the near surface groundwater in the riparian zone. The patterns were observed in the Weierbach headwater catchment in Luxembourg. The catchment is covering an area of 0.45 km2, is entirely covered by forest and is dominated by a schistous substratum. DOC concentration at the outlet of the catchment was measured with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH) with a high frequency of 15 minutes over several months. Discharge was measured with an ISCO 4120 Flow Logger. During the growing season, stream flow shows a frequently observed diurnal pattern with discharge minima in the afternoon. During the dormant season, a long dry period with daily air temperature amplitudes of around 10 ° C occurred in March and April 2014, with discharge maxima in the afternoon. The daily air temperature amplitude led to diurnal variations in the water temperature of the upper 10 cm of the riparian zone. Higher riparian water temperatures cause a decrease in water viscosity and according to the Hagen-Poiseuille equation, the volumetric flow rate is inversely proportional to viscosity. Based on the Hagen-Poiseuille equation and the viscosity changes of water, we calculated higher flow rates of near surface groundwater through the riparian zone into the stream in the afternoon which explains the stream flow maxima in the afternoon. With the start of the growing season, the viscosity

  16. Rates, Delays, and Completeness of General Practitioners' Responses to a Postal Versus Web-Based Survey: A Randomized Trial.

    PubMed

    Sebo, Paul; Maisonneuve, Hubert; Cerutti, Bernard; Fournier, Jean Pascal; Senn, Nicolas; Haller, Dagmar M

    2017-03-22

    Web-based surveys have become a new and popular method for collecting data, but only a few studies have directly compared postal and Web-based surveys among physicians, and none to our knowledge among general practitioners (GPs). Our aim is to compare two modes of survey delivery (postal and Web-based) in terms of participation rates, response times, and completeness of questionnaires in a study assessing GPs' preventive practices. This randomized study was conducted in Western Switzerland (Geneva and Vaud) and in France (Alsace and Pays de la Loire) in 2015. A random selection of community-based GPs (1000 GPs in Switzerland and 2400 GPs in France) were randomly allocated to receive a questionnaire about preventive care activities either by post (n=700 in Switzerland, n=400 in France) or by email (n=300 in Switzerland, n=2000 in France). Reminder messages were sent once in the postal group and twice in the Web-based group. Any GPs practicing only complementary and alternative medicine were excluded from the study. Among the 3400 contacted GPs, 764 (22.47%, 95% CI 21.07%-23.87%) returned the questionnaire. Compared to the postal group, the participation rate in the Web-based group was more than four times lower (246/2300, 10.70% vs 518/1100, 47.09%, P<.001), but median response time was much shorter (1 day vs 1-3 weeks, P<.001) and the number of GPs having fully completed the questionnaire was almost twice as high (157/246, 63.8% vs 179/518, 34.6%, P<.001). Web-based surveys offer many advantages such as reduced response time, higher completeness of data, and large cost savings, but our findings suggest that postal surveys can be still considered for GP research. The use of mixed-mode approaches is probably a good strategy to increase GPs' participation in surveys while reducing costs. ©Paul Sebo, Hubert Maisonneuve, Bernard Cerutti, Jean Pascal Fournier, Nicolas Senn, Dagmar M Haller. Originally published in the Journal of Medical Internet Research (http

  17. Testing Dragonflies as Species Richness Indicators in a Fragmented Subtropical Atlantic Forest Environment.

    PubMed

    Renner, S; Sahlén, G; Périco, E

    2016-06-01

    We surveyed 15 bodies of water among remnants of the Atlantic Forest biome in southern Brazil for adult dragonflies and damselflies to test whether an empirical selection method for diversity indicators could be applied in a subtropical ecosystem, where limited ecological knowledge on species level is available. We found a regional species pool of 34 species distributed in a nested subset pattern with a mean of 11.2 species per locality. There was a pronounced difference in species composition between spring, summer, and autumn, but no differences in species numbers between seasons. Two species, Homeoura chelifera (Selys) and Ischnura capreolus (Hagen), were the strongest candidates for regional diversity indicators, being found only at species-rich localities in our surveyed area and likewise in an undisturbed national forest reserve, serving as a reference site for the Atlantic Forest. Using our selection method, we found it possible to obtain a tentative list of diversity indicators without having detailed ecological information of each species, providing a reference site is available for comparison. The method thus allows for indicator species to be selected in blanco from taxonomic groups that are little known. We hence argue that Odonata can already be incorporated in ongoing assessment programs in the Neotropics, which would also increase the ecological knowledge of the group and allow extrapolation to other taxa.

  18. Microparticle tracking velocimetry as a tool for microfluidic flow measurements

    NASA Astrophysics Data System (ADS)

    Salipante, Paul; Hudson, Steven D.; Schmidt, James W.; Wright, John D.

    2017-07-01

    The accurate measurement of flows in microfluidic channels is important for commercial and research applications. We compare the accuracy of flow measurement techniques over a wide range flows. Flow measurements made using holographic microparticle tracking velocimetry (µPTV) and a gravimetric flow standard over the range of 0.5-100 nL/s agree within 0.25%, well within the uncertainty of the two flow systems. Two commercial thermal flow sensors were used as the intermediaries (transfer standards) between the two flow measurement systems. The gravimetric flow standard was used to calibrate the thermal flow sensors by measuring the rate of change of the mass of liquid in a beaker on a micro-balance as it fills. The holographic µPTV flow measurements were made in a rectangular channel and the flow was seeded with 1 µm diameter polystyrene spheres. The volumetric flow was calculated using the Hagen-Pouiseille solution for a rectangular channel. The uncertainty of both flow measurement systems is given. For the gravimetric standard, relative uncertainty increased for decreasing flows due to surface tension forces between the pipette carrying the flow and the free surface of the liquid in the beaker. The uncertainty of the holographic µPTV measurements did not vary significantly over the measured flow range, and thus comparatively are especially useful at low flow velocities.

  19. Understanding the role of pore size homogeneity in the water transport through graphene layers.

    PubMed

    Su, Jiaye; Zhao, Yunzhen; Fang, Chang

    2018-06-01

    Graphene is a versatile 2D material and attracts an increasing amount of attention from a broad scientific community, including novel nanofluidic devices. In this work, we use molecular dynamics simulations to study the pressure driven water transport through graphene layers, focusing on the pore size homogeneity, realized by the arrangement of two pore sizes. For a given layer number, we find that water flux exhibits an excellent linear behavior with pressure, in agreement with the prediction of the Hagen-Poiseuille equation. Interestingly, the flux for concentrated pore size distribution is around two times larger than that of a uniform distribution. More surprisingly, under a given pressure, the water flux changes in an opposite way for these two distributions, where the flux ratio almost increases linearly with the layer number. For the largest layer number, more distributions suggest the same conclusion that higher water flux can be attained for more concentrated pore size distributions. Similar differences for the water translocation time and occupancy are also identified. The major reason for these results should clearly be due to the hydrogen bond and density profile distributions. Our results are helpful to delineate the exquisite role of pore size homogeneity, and should have great implications for the design of high flux nanofluidic devices and inversely the detection of pore structures.

  20. [An anatomical wax of the deep structures of the pelvic limb (by Tramond, 19th century): observation of the tridimensional photographic rotation].

    PubMed

    Cazenoves, A; Le Floch-Prigent, P

    2011-06-01

    Anatomical wax modelling was widely used during the 19(th) century, especially in France and Italy. In Paris, The Tramond house was specialized in the realization of this kind of samples. The sample was placed on two large horizontal marble disks, rotating every 5°. We could then describe the sample, verify its anatomical accuracy and also perform a virtual reconstruction with Quick Time Reality QTVR(®) software. The muscular, nervous and arterial elements were represented. We divided the description in three parts: (1) lumbar, pelvic and femoral; (2) femoro-tibial; and (3) tibio-tarsian. We focused the anatomical description on the sciatic nerve; on the organization of the muscles of the gluteal region and the neurovascular organization; and on arterial segmentation. This sample was getting damaged with time, noticeably the representation of the nerves, which are very thin and so, very fragile. Nowadays, 3D representation of the dissected human body is more common, with new techniques such as plastination (Von Hagen's type), which allows one to preserve all the anatomical elements of the subject. This paper and the realization of the virtual museum also aim to participate in a work memory, which recognize the knowledge of the anatomist of wax makers, their teaching quality remained unequalled as their obvious artistical value. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  1. Auxin Controls Arabidopsis Adventitious Root Initiation by Regulating Jasmonic Acid Homeostasis[W

    PubMed Central

    Gutierrez, Laurent; Mongelard, Gaëlle; Floková, Kristýna; Păcurar, Daniel I.; Novák, Ondřej; Staswick, Paul; Kowalczyk, Mariusz; Păcurar, Monica; Demailly, Hervé; Geiss, Gaia; Bellini, Catherine

    2012-01-01

    Vegetative shoot-based propagation of plants, including mass propagation of elite genotypes, is dependent on the development of shoot-borne roots, which are also called adventitious roots. Multiple endogenous and environmental factors control the complex process of adventitious rooting. In the past few years, we have shown that the auxin response factors ARF6 and ARF8, targets of the microRNA miR167, are positive regulators of adventitious rooting, whereas ARF17, a target of miR160, is a negative regulator. We showed that these genes have overlapping expression profiles during adventitious rooting and that they regulate each other’s expression at the transcriptional and posttranscriptional levels by modulating the homeostasis of miR160 and miR167. We demonstrate here that this complex network of transcription factors regulates the expression of three auxin-inducible Gretchen Hagen3 (GH3) genes, GH3.3, GH3.5, and GH3.6, encoding acyl-acid-amido synthetases. We show that these three GH3 genes are required for fine-tuning adventitious root initiation in the Arabidopsis thaliana hypocotyl, and we demonstrate that they act by modulating jasmonic acid homeostasis. We propose a model in which adventitious rooting is an adaptive developmental response involving crosstalk between the auxin and jasmonate regulatory pathways. PMID:22730403

  2. MP estimation applied to platykurtic sets of geodetic observations

    NASA Astrophysics Data System (ADS)

    Wiśniewski, Zbigniew

    2017-06-01

    MP estimation is a method which concerns estimating of the location parameters when the probabilistic models of observations differ from the normal distributions in the kurtosis or asymmetry. The system of Pearson's distributions is the probabilistic basis for the method. So far, such a method was applied and analyzed mostly for leptokurtic or mesokurtic distributions (Pearson's distributions of types IV or VII), which predominate practical cases. The analyses of geodetic or astronomical observations show that we may also deal with sets which have moderate asymmetry or small negative excess kurtosis. Asymmetry might result from the influence of many small systematic errors, which were not eliminated during preprocessing of data. The excess kurtosis can be related with bigger or smaller (in relations to the Hagen hypothesis) frequency of occurrence of the elementary errors which are close to zero. Considering that fact, this paper focuses on the estimation with application of the Pearson platykurtic distributions of types I or II. The paper presents the solution of the corresponding optimization problem and its basic properties. Although platykurtic distributions are rare in practice, it was an interesting issue to find out what results can be provided by MP estimation in the case of such observation distributions. The numerical tests which are presented in the paper are rather limited; however, they allow us to draw some general conclusions.

  3. Not Just Horsing Around: The Impact of Equine-Assisted Learning on Levels of Hope and Depression in At-Risk Adolescents.

    PubMed

    Frederick, Karen E; Ivey Hatz, Julie; Lanning, Beth

    2015-10-01

    Equine-assisted learning (EAL) is an experiential modality which utilizes horses to provide a unique learning experience for personal growth. Research by Damon et al. (Appl Dev Sci 7:119-128, 2003) suggests a positive relationship between hope and positive developmental trajectories. Hagen et al. (Am J Orthopsychiatr 75:211-219, 2005) showed hope to be a protective factor associated with adaptive functioning in at-risk youth. Ashby et al. (J Couns Dev 89:131-139, 2011) found a significant inverse relationship between hope and depression: as hope increases, depression decreases. The current study investigates the impact of a non-riding EAL curriculum entitled L.A.S.S.O. (Leading Adolescents to Successful School Outcomes) on levels of hope and depression in at-risk youth. The study uses an experimental design with longitudinal, repeated measures. Participants were randomly assigned to treatment and control groups. Participants in the treatment received 5 weeks of EAL, while participants in the control group received treatment as usual. Repeated measures ANOVA of participants' levels of hope and depression showed statistically significant improvements in the treatment group as compared with the control group. Even a brief (5-week) intervention of EAL had a positive impact on the lives and attitudes of at-risk adolescents, with increased levels of hope and decreased levels of depression.

  4. The Body Worlds Exhibits and Juvenile Understandings of Death: Do We Educate Children to Science or to Voyeurism?

    PubMed

    Bianucci, R; Soldini, M; Di Vella, G; Verzé, L; Day, J

    2015-01-01

    Gunther von Hagens' development of plastination as a method for preserving human remains has enabled his public display of skinless, dissected bodies in a series of popular international exhibitions entitled Body Worlds. These spectacular displays claim to be educative, democratizing the study of anatomy and liberating it from the traditional confines of professional medical study. However, Body Worlds has raised various ethical objections to its commercial purpose, sourcing of some bodies and arrangement of bodies in poses or dissections that some viewers find offensive. Here we consider a different, often overlooked ethical conundrum raised by these exhibitions: the likelihood that the viewing of plastinates posed in 'frozen motion' is ill‑suited to the psychological development of young children (5-10 years old) whose understanding of death is still in formation. Often young children mistake corpses for models, even for living beings if they are posed in arrested motion. The educative value of Body Worlds for younger viewers is questionable and the display may even interfere with their understanding of death. If the exhibition of human remains can be justified where their authenticity can be made known to viewers and the remains invested by them with sympathetic emotional meaning, it may be pointless if not unethical to show quasi‑lifelike posed plastinates to young children in lieu of replica models.

  5. On-line coupling of immobilized cytochrome P450 microreactor and capillary electrophoresis: A promising tool for drug development.

    PubMed

    Schejbal, Jan; Řemínek, Roman; Zeman, Lukáš; Mádr, Aleš; Glatz, Zdeněk

    2016-03-11

    In this work, the combination of an immobilized enzyme microreactor (IMER) based on the clinically important isoform cytochrome P450 2C9 (CYP2C9) with capillary electrophoresis (CE) is presented. The CYP2C9 was attached to magnetic SiMAG-carboxyl microparticles using the carbodiimide method. The formation of an IMER in the inlet part of the separation capillary was ensured by two permanent magnets fixed in a cassette from the CE apparatus in the repulsive arrangement. The resulting on-line system provides an integration of enzyme reaction mixing and incubation, reaction products separation, detection and quantification into a single fully automated procedure with the possibility of repetitive use of the enzyme and minuscule amounts of reactant consumption. The on-line kinetic and inhibition studies of CYP2C9's reaction with diclofenac as a model substrate and sulfaphenazole as a model inhibitor were conducted in order to demonstrate its practical applicability. Values of the apparent Michalis-Menten constant, apparent maximum reaction velocity, Hill coefficient, apparent inhibition constant and half-maximal inhibition concentration were determined on the basis of the calculation of the effective substrate and inhibitor concentrations inside the capillary IMER using a model described by the Hagen-Poisseulle law and a novel enhanced model that reflects the influence of the reactants' diffusion during the injection process. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Starling forces drive intracranial water exchange during normal and pathological states.

    PubMed

    Linninger, Andreas A; Xu, Colin; Tangen, Kevin; Hartung, Grant

    2017-12-31

    To quantify the exchange of water between cerebral compartments, specifically blood, tissue, perivascular pathways, and cerebrospinal fluid-filled spaces, on the basis of experimental data and to propose a dynamic global model of water flux through the entire brain to elucidate functionally relevant fluid exchange phenomena. The mechanistic computer model to predict brain water shifts is discretized by cerebral compartments into nodes. Water and species flux is calculated between these nodes across a network of arcs driven by Hagen-Poiseuille flow (blood), Darcy flow (interstitial fluid transport), and Starling's Law (transmembrane fluid exchange). Compartment compliance is accounted for using a pressure-volume relationship to enforce the Monro-Kellie doctrine. This nonlinear system of differential equations is solved implicitly using MATLAB software. The model predictions of intraventricular osmotic injection caused a pressure rise from 10 to 22 mmHg, followed by a taper to 14 mmHg over 100 minutes. The computational results are compared to experimental data with R2=0.929. Moreover, simulated osmotic therapy of systemic (blood) injection reduced intracranial pressure from 25 to 10 mmHg. The modeled volume and intracranial pressure changes following cerebral edema agree with experimental trends observed in animal models with R2=0.997. The model successfully predicted time course and the efficacy of osmotic therapy for clearing cerebral edema. Furthermore, the mathematical model implicated the perivascular pathways as a possible conduit for water and solute exchange. This was a first step to quantify fluid exchange throughout the brain.

  7. Jasmonic acid-isoleucine formation in grapevine (Vitis vinifera L.) by two enzymes with distinct transcription profiles.

    PubMed

    Böttcher, Christine; Burbidge, Crista A; di Rienzo, Valentina; Boss, Paul K; Davies, Christopher

    2015-07-01

    The plant hormone jasmonic acid (JA) is essential for stress responses and the formation of reproductive organs, but its role in fruit development and ripening is unclear. Conjugation of JA to isoleucine is a crucial step in the JA signaling pathway since only JA-Ile is recognized by the jasmonate receptor. The conjugation reaction is catalyzed by JA-amido synthetases, belonging to the family of Gretchen Hagen3 (GH3) proteins. Here, in vitro studies of two grapevine (Vitis vinifera L. cv Shiraz) GH3 enzymes, VvGH3-7 and VvGH3-9, demonstrated JA-conjugating activities with an overlapping range of amino acid substrates, including isoleucine. Expression studies of the corresponding genes in grape berries combined with JA and JA-Ile measurements suggested a primary role for JA signaling in fruit set and cell division and did not support an involvement of JA in the ripening process. In response to methyl JA (MeJA) treatment, and in wounded and unwounded (distal) leaves, VvGH3-9 transcripts accumulated, indicating a participation in the JA response. In contrast, VvGH3-7 was unresponsive to MeJA and local wounding, demonstrating a differential transcriptional regulation of VvGH3-7 and VvGH3-9. The transient induction of VvGH3-7 in unwounded, distal leaves was suggestive of the involvement of an unknown mobile wound signal. © 2014 Institute of Botany, Chinese Academy of Sciences.

  8. Electroviscous Effects in Ceramic Nanofiltration Membranes.

    PubMed

    Farsi, Ali; Boffa, Vittorio; Christensen, Morten Lykkegaard

    2015-11-16

    Membrane permeability and salt rejection of a γ-alumina nanofiltration membrane were studied and modeled for different salt solutions. Salt rejection was predicted by using the Donnan-steric pore model, in which the extended Nernst-Planck equation was applied to predict ion transport through the pores. The solvent flux was modeled by using the Hagen-Poiseuille equation by introducing electroviscosity instead of bulk viscosity. γ-Alumina particles were used for ζ-potential measurements. The ζ-potential measurements show that monovalent ions did not adsorb on the γ-alumina surface, whereas divalent ions were highly adsorbed. Thus, for divalent ions, the model was modified, owing to pore shrinkage caused by ion adsorption. The ζ-potential lowered the membrane permeability, especially for membranes with a pore radius lower than 3 nm, a ζ-potential higher than 20 mV, and an ionic strength lower than 0.01 m. The rejection model showed that, for a pore radius lower than 3 nm and for solutions with ionic strengths lower than 0.01 m, there is an optimum ζ-potential for rejection, because of the concurrent effects of electromigration and convection. Hence, the model can be used as a prediction tool to optimize membrane perm-selectivity by designing a specific pore size and surface charge for application at specific ionic strengths and pH levels. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Evaluation of Low-Energy Microwaves Technology (Termatrac) for Detecting Western Drywood Termite in a Simulated Drywall System.

    PubMed

    Taravati, Siavash

    2018-05-28

    Detecting drywood termites in structures is very challenging. Microwaves technology (Termatrac T3i) is a nondestructive method for detecting drywood termites in structures. Termatrac device and its mobile application provide a bar as well as a line graph when detecting insect movements, but interpreting these graphs is very subjective. In this paper, Termatrac's output signal is quantified using a new method to study the effect of wall layers, wood type, and termite density on signal strength measured as area under curve in a simulated drywall system in laboratory. Two experiments were conducted on Termatrac T3i at its maximum sensitivity (Gain: 10). In experiment I, HEXBUG Nano was used as a source of movement/vibration and two wood types were used in which the wall layers significantly predicted signal strength, but wood type did not. In experiment II, two different densities of live western drywood termites, Incisitermes minor (Hagen) (Isoptera: Kalotermitidae), were used to study the effect of termite density on signal strength. Interestingly, termite density did not significantly predict signal strength. The maximum reliable wood depth for detecting termites was 5 cm. Microwaves produced by Termatrac also showed good penetration into drywall and produced detectable signals even on a single drywood termite which confirms manufacturer's claim. Suggestions on using and improving microwaves technology for detecting termites is provided which can potentially be applied to other types of insects and noninsect animals.

  10. Linking the Modern Distribution of Biogenic Proxies in High Arctic Greenland Shelf Sediments to Sea Ice, Primary Production, and Arctic-Atlantic Inflow

    NASA Astrophysics Data System (ADS)

    Limoges, Audrey; Ribeiro, Sofia; Weckström, Kaarina; Heikkilä, Maija; Zamelczyk, Katarzyna; Andersen, Thorbjørn J.; Tallberg, Petra; Massé, Guillaume; Rysgaard, Søren; Nørgaard-Pedersen, Niels; Seidenkrantz, Marit-Solveig

    2018-03-01

    The eastern north coast of Greenland is considered to be highly sensitive to the ongoing Arctic warming, but there is a general lack of data on modern conditions and in particular on the modern distribution of climate and environmental proxies to provide a baseline and context for studies on past variability. Here we present a detailed investigation of 11 biogenic proxies preserved in surface sediments from the remote High Arctic Wandel Sea shelf, the entrance to the Independence, Hagen, and Danmark fjords. The composition of organic matter (organic carbon, C:N ratios, δ13C, δ15N, biogenic silica, and IP25) and microfossil assemblages revealed an overall low primary production dominated by benthic diatoms, especially at the shallow sites. While the benthic and planktic foraminiferal assemblages underline the intrusion of chilled Atlantic waters into the deeper parts of the study area, the distribution of organic-walled dinoflagellate cysts is controlled by the local bathymetry and sea ice conditions. The distribution of the dinoflagellate cyst Polarella glacialis matches that of seasonal sea ice and the specific biomarker IP25, highlighting the potential of this species for paleo sea ice studies. The information inferred from our multiproxy study has important implications for the interpretation of the biogenic-proxy signal preserved in sediments from circum-Arctic fjords and shelf regions and can serve as a baseline for future studies. This is the first study of its kind in this area.

  11. Thermal radiative and thermodynamic properties of solid and liquid uranium and plutonium carbides in the visible-near-infrared range

    NASA Astrophysics Data System (ADS)

    Fisenko, Anatoliy I.; Lemberg, Vladimir F.

    2016-09-01

    The knowledge of thermal radiative and thermodynamic properties of uranium and plutonium carbides under extreme conditions is essential for designing a new metallic fuel materials for next generation of a nuclear reactor. The present work is devoted to the study of the thermal radiative and thermodynamic properties of liquid and solid uranium and plutonium carbides at their melting/freezing temperatures. The Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, pressure, and normal total emissivity are calculated using experimental data for the frequency dependence of the normal spectral emissivity of liquid and solid uranium and plutonium carbides in the visible-near infrared range. It is shown that the thermal radiative and thermodynamic functions of uranium carbide have a slight difference during liquid-to-solid transition. Unlike UC, such a difference between these functions have not been established for plutonium carbide. The calculated values for the normal total emissivity of uranium and plutonium carbides at their melting temperatures is in good agreement with experimental data. The obtained results allow to calculate the thermal radiative and thermodynamic properties of liquid and solid uranium and plutonium carbides for any size of samples. Based on the model of Hagen-Rubens and the Wiedemann-Franz law, a new method to determine the thermal conductivity of metals and carbides at the melting points is proposed.

  12. Genome-wide identification, expression analysis of auxin-responsive GH3 family genes in maize (Zea mays L.) under abiotic stresses.

    PubMed

    Feng, Shangguo; Yue, Runqing; Tao, Sun; Yang, Yanjun; Zhang, Lei; Xu, Mingfeng; Wang, Huizhong; Shen, Chenjia

    2015-09-01

    Auxin is involved in different aspects of plant growth and development by regulating the expression of auxin-responsive family genes. As one of the three major auxin-responsive families, GH3 (Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid (IAA) to amino acids. However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown. Here, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmGH3 family genes from maize. The results showed that 13 ZmGH3 genes were mapped on five maize chromosomes (total 10 chromosomes). Highly diversified gene structures and tissue-specific expression patterns suggested the possibility of function diversification for these genes in response to environmental stresses and hormone stimuli. The expression patterns of ZmGH3 genes are responsive to several abiotic stresses (salt, drought and cadmium) and major stress-related hormones (abscisic acid, salicylic acid and jasmonic acid). Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The responsiveness of ZmGH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that ZmGH3s are involved in maize tolerance to environmental stresses. © 2014 Institute of Botany, Chinese Academy of Sciences.

  13. Modeling NAPL dissolution from pendular rings in idealized porous media

    NASA Astrophysics Data System (ADS)

    Huang, Junqi; Christ, John A.; Goltz, Mark N.; Demond, Avery H.

    2015-10-01

    The dissolution rate of nonaqueous phase liquid (NAPL) often governs the remediation time frame at subsurface hazardous waste sites. Most formulations for estimating this rate are empirical and assume that the NAPL is the nonwetting fluid. However, field evidence suggests that some waste sites might be organic wet. Thus, formulations that assume the NAPL is nonwetting may be inappropriate for estimating the rates of NAPL dissolution. An exact solution to the Young-Laplace equation, assuming NAPL resides as pendular rings around the contact points of porous media idealized as spherical particles in a hexagonal close packing arrangement, is presented in this work to provide a theoretical prediction for NAPL-water interfacial area. This analytic expression for interfacial area is then coupled with an exact solution to the advection-diffusion equation in a capillary tube assuming Hagen-Poiseuille flow to provide a theoretical means of calculating the mass transfer rate coefficient for dissolution at the NAPL-water interface in an organic-wet system. A comparison of the predictions from this theoretical model with predictions from empirically derived formulations from the literature for water-wet systems showed a consistent range of values for the mass transfer rate coefficient, despite the significant differences in model foundations (water wetting versus NAPL wetting, theoretical versus empirical). This finding implies that, under these system conditions, the important parameter is interfacial area, with a lesser role played by NAPL configuration.

  14. Computer aided approximation of flow rate through systemic-pulmonary arterial shunts (SPAS).

    PubMed

    Vennemann, Peter; Montag, Michael; Peters, Franz; Merzkirch, Wolfgang

    2012-02-22

    The discrimination of flow rates through bronchial arteries that are affected by pathological SPAS today still happens solely qualitatively. A reproducible quantification of flow rates, however, would enable the comprehension of phenomena like the intensified shunt perfusion seen in cases of chronic inflammations or the characterization of SPAS that may cause cardiovascular problems. A computational program is developed, that allows the modeling of individual bronchial arteries on the basis of the information provided by angiography. Angiographic images are available from the standard clinical assessment of SPAS. The flow through continuous and geometrically measurable vessel segments and SPAS is given by the law of Hagen-Poiseuille. The discharge through healthy branches is calculated by means of allometric scaling laws. The simulation results are verified by flow experiments in artificial vessel networks made of glass and PE tubing. The experimental set-up mimics realistic, pulsating pressure and flow conditions. When applied to the artificial vessel networks, the model described herein provides results for the volumetric flow rate that differ from values measured in laboratory experiments by <6%. The computer model is also applied to real angiographic images. Due to inaccuracies during the deduction of the geometry and due to necessary simplifications of the model, we expect significant deviations between calculated and real flow rates in bronchial systems. Nevertheless, the presented method enables the physician to objectively estimate the order of magnitude of volumetric flow through individual SPAS fairly independently from his experience and without the need of measurements additional to the mandatory angiography.

  15. A new experimental apparatus for emissivity measurements of steel and the application of multi-wavelength thermometry to continuous casting billets

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Hu, Zhenwei; Xie, Zhi; Yan, Ming

    2018-05-01

    An experimental apparatus has been designed for measuring the emissivity of a steel surface in both vacuum and oxidation atmosphere. The sample is heated with the method of electromagnetic induction in order to ensure the temperature uniformity. The radiance emitted from a sample is measured using a fiber-optic Fourier transform infrared spectrometer. Using this unique apparatus, we investigated the spectral (2-6 μm) and directional (0°-86°) emissivity of stainless steel 304 with different degrees of surface oxidation at temperatures ranging from 800 to 1100 °C. The experimental results show that the emissivity increases slightly with increasing temperature, which accords with the Hagen-Rubens relation. The emissivity increases rapidly at the initial stage of oxidation, but gradually reaches to a constant value after 20 min. In addition, the directional emissivity has a maximum value at the measuring angle of about 75°. The maximum uncertainty of emissivity is only 3.0% over all the measuring ranges, indicating that this experimental apparatus has a high reliability. In order to measure the surface temperature of casting billets based on multi-wavelength thermometry, the bivariate emissivity function with the two variables, wavelength and temperature, is determined. Temperature measurement results based on our technique are compared with those from common dual-wavelength radiation thermometry. Our approach reduces the measured temperature fluctuation from ±20.7 °C to ±2.8 °C and reflects the temperature variation with the changes of production parameters in real time.

  16. Starling forces drive intracranial water exchange during normal and pathological states

    PubMed Central

    Linninger, Andreas A.; Xu, Colin; Tangen, Kevin; Hartung, Grant

    2017-01-01

    Aim To quantify the exchange of water between cerebral compartments, specifically blood, tissue, perivascular pathways, and cerebrospinal fluid-filled spaces, on the basis of experimental data and to propose a dynamic global model of water flux through the entire brain to elucidate functionally relevant fluid exchange phenomena. Methods The mechanistic computer model to predict brain water shifts is discretized by cerebral compartments into nodes. Water and species flux is calculated between these nodes across a network of arcs driven by Hagen-Poiseuille flow (blood), Darcy flow (interstitial fluid transport), and Starling’s Law (transmembrane fluid exchange). Compartment compliance is accounted for using a pressure-volume relationship to enforce the Monro-Kellie doctrine. This nonlinear system of differential equations is solved implicitly using MATLAB software. Results The model predictions of intraventricular osmotic injection caused a pressure rise from 10 to 22 mmHg, followed by a taper to 14 mmHg over 100 minutes. The computational results are compared to experimental data with R2 = 0.929. Moreover, simulated osmotic therapy of systemic (blood) injection reduced intracranial pressure from 25 to 10 mmHg. The modeled volume and intracranial pressure changes following cerebral edema agree with experimental trends observed in animal models with R2 = 0.997. Conclusion The model successfully predicted time course and the efficacy of osmotic therapy for clearing cerebral edema. Furthermore, the mathematical model implicated the perivascular pathways as a possible conduit for water and solute exchange. This was a first step to quantify fluid exchange throughout the brain. PMID:29308830

  17. Effects of microstructure on water imbibition in sandstones using X-ray computed tomography and neutron radiography

    NASA Astrophysics Data System (ADS)

    Zhao, Yixin; Xue, Shanbin; Han, Songbai; Chen, Zhongwei; Liu, Shimin; Elsworth, Derek; He, Linfeng; Cai, Jianchao; Liu, Yuntao; Chen, Dongfeng

    2017-07-01

    Capillary imbibition in variably saturated porous media is important in defining displacement processes and transport in the vadose zone and in low-permeability barriers and reservoirs. Nonintrusive imaging in real time offers the potential to examine critical impacts of heterogeneity and surface properties on imbibition dynamics. Neutron radiography is applied as a powerful imaging tool to observe temporal changes in the spatial distribution of water in porous materials. We analyze water imbibition in both homogeneous and heterogeneous low-permeability sandstones. Dynamic observations of the advance of the imbibition front with time are compared with characterizations of microstructure (via high-resolution X-ray computed tomography (CT)), pore size distribution (Mercury Intrusion Porosimetry), and permeability of the contrasting samples. We use an automated method to detect the progress of wetting front with time and link this to square-root-of-time progress. These data are used to estimate the effect of microstructure on water sorptivity from a modified Lucas-Washburn equation. Moreover, a model is established to calculate the maximum capillary diameter by modifying the Hagen-Poiseuille and Young-Laplace equations based on fractal theory. Comparing the calculated maximum capillary diameter with the maximum pore diameter (from high-resolution CT) shows congruence between the two independent methods for the homogeneous silty sandstone but less effectively for the heterogeneous sandstone. Finally, we use these data to link observed response with the physical characteristics of the contrasting media—homogeneous versus heterogeneous—and to demonstrate the sensitivity of sorptivity expressly to tortuosity rather than porosity in low-permeability sandstones.

  18. Nanofluid transport in a living soft microtube

    NASA Astrophysics Data System (ADS)

    Sung, Baeckkyoung; Kim, Se Hoon; Lee, Sungwoo; Lim, Jaekwan; Lee, Jin-Kyu; Soh, Kwang-Sup

    2015-09-01

    The mechanism of hydrodynamic transport of nanoparticles in living tissues by intrinsic lymphatic pumping remains one of the fundamental questions in the field of nanomedicine. However, despite its importance, direct visualization of the nanofluid transport mechanism has not been achieved. In this article, we report a novel in situ fluorescence bioimaging method for observing real-time microflow patterns of nanofluids confined in a contracting and expanding soft microtube. This method allows for physiological monitoring of spatiotemporally resolved microfluidic behaviour and channel undulation during the peristaltic transport of fluorescent nanoparticle suspensions by lymph vessels embedded in bulky tissues at the location of the hindlimb. The fluorescent nanofluid conferred a high optical contrast for the visualization of the lymphatic microtube, with which the concentration and viscosity of the nanofluid could be determined. The nanofluid and microtube mechanics of the hindlimb lymph vessels exhibited similar behaviours as the previously described base fluid flow of peristaltic mesenteric lymph vessels. Specifically, the microtube contraction and expansion induced increased forward flows, and a reverse flow developed at the maximum contraction, all of which corresponded to Poiseuille flow and implied that higher tube wall shear stress was related to increased axial flow velocity. On the other hand, our study identified a highly heterogeneous flow pattern that could appear during the microtube expansion phase, whose axial velocity profile remarkably deviated from the Hagen-Poiseuille equation. In addition, the peristaltic pumping power was estimated to be on the nanowatt order of magnitude. Finally, we discuss the possible applications of this nanofluidic model system in the context of nanobiotechnology.

  19. Prevalence of a koinobiont endoparasitoid Misotermes mindeni (Diptera: Phoridae) in colonies of the fungus-growing termite Macrotermes gilvus (Blattodea: Termitidae) in Malaysia.

    PubMed

    Foo, Foong-Kuan; Singham, G Veera; Othman, Ahmad Sofiman; Lee, Chow-Yang

    2011-10-01

    A survey of the infestation rate of colonies of Macrotermes gilvus (Hagen) (Termitidae: Macrotermitinae) with the koinobiont endoparasitoid Misotermes mindeni Disney & Neoh (Diptera: Phoridae) was conducted in Malaysia from September 2009 to January 2011 in the states of Kedah, Penang, Perak, Selangor, Kuala Lumpur, Johor, Terengganu, and Sarawak. Of the 1,125 M. gilvus mounds surveyed, 12.4% contained termites parasitized by M. mindeni and these mounds occurred only in the states of Penang and Perak. High frequencies of mounds containing parasitized termites were found at sites in Penang: Bayan Lepas (21.1%), Minden Campus of Universiti Sains Malaysia ([USM]; 24.5%), Teluk Bahang (28.0%), and Bukit Mertajam (35.0%); the lowest frequency (4.0%) was recorded from Gelugor. The parasitized colonies at all sites were classified as healthy, with exception of several from the Minden Campus of USM (96.4% healthy) and Ayer Itam (87.5% healthy). Most parasitized colonies (71.2%) had a low level of M. mindeni infestation. Only 16.7 and 12.1% of the infested colonies had moderate or high parasite infestation levels, respectively. The height of infected mounds was significantly higher than that of the healthy mounds, but there was no difference between the mound diameters of infested and uninfested mounds. Parasite infestation level was not significantly correlated with mound height or mound diameter. The ambient light intensity at sites with infested mounds was significantly lower than that of uninfested mounds. There was also a significant negative relationship between light intensity and degree of parasitism.

  20. Development and evaluation of a water level proportional water sampler

    NASA Astrophysics Data System (ADS)

    Schneider, P.; Lange, A.; Doppler, T.

    2013-12-01

    We developed and adapted a new type of sampler for time-integrated, water level proportional water quality sampling (e.g. nutrients, contaminants and stable isotopes). Our samplers are designed for sampling small to mid-size streams based on the law of Hagen-Poiseuille, where a capillary (or a valve) limits the sampling aliquot by reducing the air flux out of a submersed plastic (HDPE) sampling container. They are good alternatives to battery-operated automated water samplers when working in remote areas, or at streams that are characterized by pronounced daily discharge variations such as glacier streams. We evaluated our samplers against standard automated water samplers (ISCO 2900 and ISCO 6712) during the snowmelt in the Black Forest and the Alps and tested them in remote glacial catchments in Iceland, Switzerland and Kyrgyzstan. The results clearly showed that our samplers are an adequate tool for time-integrated, water level proportional water sampling at remote test sites, as they do not need batteries, are relatively inexpensive, lightweight, and compact. They are well suited for headwater streams - especially when sampling for stable isotopes - as the sampled water is perfectly protected against evaporation. Moreover, our samplers have a reduced risk of icing in cold environments, as they are installed submersed in water, whereas automated samplers (typically installed outside the stream) may get clogged due to icing of hoses. Based on this study, we find these samplers to be an adequate replacement for automated samplers when time-integrated sampling or solute load estimates are the main monitoring tasks.

  1. Phylogeography of the termite Macrotermes gilvus and insight into ancient dispersal corridors in Pleistocene Southeast Asia

    PubMed Central

    Othman, Ahmad Sofiman; Lee, Chow-Yang

    2017-01-01

    Dispersal of soil-dwelling organisms via the repeatedly exposed Sunda shelf through much of the Pleistocene in Southeast Asia has not been studied extensively, especially for invertebrates. Here we investigated the phylogeography of an endemic termite species, Macrotermes gilvus (Hagen), to elucidate the spatiotemporal dynamics of dispersal routes of terrestrial fauna in Pleistocene Southeast Asia. We sampled 213 termite colonies from 66 localities throughout the region. Independently inherited microsatellites and mtDNA markers were used to infer the phylogeographic framework of M. gilvus. Discrete phylogeographic analysis and molecular dating based on fossil calibration were used to infer the dynamics of M. gilvus dispersal in time and space across Southeast Asia. We found that the termite dispersal events were consistently dated within the Pleistocene time frame. The dispersal pattern was multidirectional, radiating eastwards and southwards out of Indochina, which was identified as the origin for dispersal events. We found no direct dispersal events between Sumatra and Borneo despite the presence of a terrestrial connection between them during the Pleistocene. Instead, central Java served as an important link allowing termite colonies to be established in Borneo and Sumatra. Our findings support the hypothesis of a north-south dispersal corridor in Southeast Asia and suggest the presence of alternative dispersal routes across Sundaland during the Pleistocene. For the first time, we also propose that a west-east dispersal through over-water rafting likely occurred across the Pleistocene South China Sea. We found at least two independent entry routes for terrestrial species to infiltrate Sumatra and Borneo at different times. PMID:29186140

  2. Spontaneous Symmetry Breaking as a Basis of Particle Mass

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Quigg, Chris; /Fermilab /CERN

    2007-04-01

    Electroweak theory joins electromagnetism with the weak force in a single quantum field theory, ascribing the two fundamental interactions--so different in their manifestations--to a common symmetry principle. How the electroweak gauge symmetry is hidden is one of the most urgent and challenging questions facing particle physics. The provisional answer incorporated in the ''standard model'' of particle physics was formulated in the 1960s by Higgs, by Brout & Englert, and by Guralnik, Hagen, & Kibble: The agent of electroweak symmetry breaking is an elementary scalar field whose self-interactions select a vacuum state in which the full electroweak symmetry is hidden, leavingmore » a residual phase symmetry of electromagnetism. By analogy with the Meissner effect of the superconducting phase transition, the Higgs mechanism, as it is commonly known, confers masses on the weak force carriers W{sup {+-}} and Z. It also opens the door to masses for the quarks and leptons, and shapes the world around us. It is a good story--though an incomplete story--and we do not know how much of the story is true. Experiments that explore the Fermi scale (the energy regime around 1 TeV) during the next decade will put the electroweak theory to decisive test, and may uncover new elements needed to construct a more satisfying completion of the electroweak theory. The aim of this article is to set the stage by reporting what we know and what we need to know, and to set some ''Big Questions'' that will guide our explorations.« less

  3. Can forest dieback and tree death be predicted by prior changes in wood anatomy?

    NASA Astrophysics Data System (ADS)

    Colangelo, Michele; Julio Camarero, Jesus; De Micco, Veronica; Borghetti, Marco; Gentilesca, Tiziana; Sanchez-Salguero, Raul; Ripullone, Francesco

    2017-04-01

    Climate warming is expected to amplify drought stress resulting in more intense and widespread dieback episodes and increasing mortality rates. Studies on quantitative wood anatomy and dendrochronology have demonstrated their potential to supply useful information on the causes of tree decline, although this approach is basically observational and retrospective. Moreover, the long-term reconstruction of wood anatomical features, strictly linked to the evolution of xylem anatomy plasticity through time, allow investigating hydraulic adjustments of trees. In this study, we analyzed wood-anatomical variables in two Italian oak forests where recent episodes of dieback and mortality have been reported. We analyzed in coexisting now-dead and living trees the following wood-anatomical variables: annual tree-ring area, earlywood (EW) and latewood (LW) areas, absolute and relative (%) areas occupied by vessels in the EW and LW, EW and LW vessel areas, EW and LW vessel density and vessel diameter classification. We also calculated the hydraulic diameter (Dh) for all vessels measured within each ring by weighting individual conduit diameters to correspond to the average Hagen-Poiseuille lumen theoretical hydraulic conductivity for a vessel size. Wood-anatomical analyses showed that declining and dead trees were more sensitive to drought stress compared to non declining trees, indicating different susceptibility to water shortage between trees. Dead trees did not form earlywood vessels with smaller lumen diameter than surviving trees but tended to form wider latewood vessels with a higher percentage of vessel area. We discuss the results and implications focusing on those proved more sensitive to the phenomena of decline and mortality.

  4. Essential role for uncoupling protein-3 in mitochondrial adaptation to fasting but not in fatty acid oxidation or fatty acid anion export.

    PubMed

    Seifert, Erin L; Bézaire, Véronic; Estey, Carmen; Harper, Mary-Ellen

    2008-09-12

    Uncoupling protein-3 (UCP3) is a mitochondrial inner membrane protein expressed most abundantly in skeletal muscle and to a lesser extent in heart and brown adipose tissue. Evidence supports a role for UCP3 in fatty acid oxidation (FAO); however, the underlying mechanism has not been explored. In 2001 we proposed a role for UCP3 in fatty acid export, leading to higher FAO rates (Himms-Hagen, J., and Harper, M. E. (2001) Exp. Biol. Med. (Maywood) 226, 78-84). Specifically, this widely held hypothesis states that during elevated FAO rates, UCP3 exports fatty acid anions, thereby maintaining mitochondrial co-enzyme A availability; reactivation of exported fatty acid anions would ultimately enable increased FAO. Here we tested mechanistic aspects of this hypothesis as well as its functional implications, namely increased FAO rates. Using complementary mechanistic approaches in mitochondria from wild-type and Ucp3(-/-) mice, we find that UCP3 is not required for FAO regardless of substrate type or supply rate covering a 20-fold range. Fatty acid anion export and reoxidation during elevated FAO, although present in skeletal muscle mitochondria, are independent of UCP3 abundance. Interestingly, UCP3 was found to be necessary for the fasting-induced enhancement of FAO rate and capacity, possibly via mitigated mitochondrial oxidative stress. Thus, although our observations indicate that UCP3 can impact FAO rates, the mechanistic basis is not via an integral function for UCP3 in the FAO machinery. Overall our data indicate a function for UCP3 in mitochondrial adaptation to perturbed cellular energy balance and integrate previous observations that have linked UCP3 to reduced oxidative stress and FAO.

  5. Changes in Sleep Duration and Sleep Timing Associated with Retirement Transitions

    PubMed Central

    Hagen, Erika W.; Barnet, Jodi H.; Hale, Lauren; Peppard, Paul E.

    2016-01-01

    Study Objectives: Investigate whether retirement transitions are associated with changes in sleep duration and sleep timing, and whether these associations are modified by age, sex, mental health, or circadian preference. Methods: The Retirement and Sleep Trajectories (REST) study is a longitudinal study consisting of four annual mailed surveys that collected information about employment, sleep, and health. Differences in reported sleep duration, bedtime and wake time between successive surveys were calculated to estimate change over 1, 2, and 3 y. Linear regression models were used to estimate changes in these sleep parameters associated with retirement 1, 2, and 3 y posttransition. Results: Retiring from full-time work was associated with bedtimes that were 30, 31, and 36 min later 1, 2, and 3 y postretirement; wake times that were 63, 69, and 78 min later; and sleep durations that were 15, 16, and 22 min longer 1, 2, and 3 y postretirement. These associations did not differ by sex or mental health status. Age and circadian preference modified the associations between retirement and change in sleep parameters; the increase in sleep duration was shorter and the wake time extension was lesser with advancing retirement age; those with evening preference had longer wake time extensions than those with morning preference. Conclusion: Transitioning to retirement is associated with longer sleep duration, later bedtimes, and later wake times. These changes were detectable about 1 y postwork transition and were persistent up to 3 y later. Citation: Hagen EW, Barnet JH, Hale L, Peppard PE. Changes in sleep duration and sleep timing associated with retirement transitions. SLEEP 2016;39(3):665–673. PMID:26564125

  6. The distribution of dragonfly larvae in a South Carolina stream: relationships with sediment type, body size, and the presence of other larvae.

    PubMed

    Worthen, Wade B; Horacek, Henry Joseph

    2015-01-01

    Dragonfly larvae were sampled in Little Creek, Greenville, SC. The distributions of five common species were described relative to sediment type, body size, and the presence of other larvae. In total, 337 quadrats (1 m by 0.5 m) were sampled by kick seine. For each quadrat, the substrate was classified as sand, sand-cobble mix, cobble, coarse, or rock, and water depth and distance from bank were measured. Larvae were identified to species, and the lengths of the body, head, and metafemur were measured. Species were distributed differently across sediment types: sanddragons, Progomphus obscurus (Rambur) (Odonata: Gomphidae), were common in sand; twin-spotted spiketails, Cordulegaster maculata Selys (Odonata: Cordulegastridae), preferred a sand-cobble mix; Maine snaketails, Ophiogomphus mainensis Packard (Odonata: Gomphidae), preferred cobble and coarse sediments; fawn darners, Boyeria vinosa (Say) (Odonata: Aeshnidae), preferred coarse sediments; and Eastern least clubtails, Stylogomphus albistylus (Hagen) (Odonata: Gomphidae), preferred coarse and rock sediments. P. obscurus and C. maculata co-occurred more frequently than expected by chance, as did O. mainensis, B. vinosa, and S. albistylus. Mean size varied among species, and species preferences contributed to differences in mean size across sediment types. There were significant negative associations among larval size classes: small larvae (<12 mm) occurred less frequently with large larvae (>15 mm) than expected by chance, and large larvae were alone in quadrats more frequently than other size classes. Species may select habitats at a large scale based on sediment type and their functional morphology, but small scale distributions are consistent with competitive displacement or intraguild predation. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  7. Susceptibility of Ceraeochrysa cubana larvae and adults to six insect growth-regulator insecticides.

    PubMed

    Ono, Éric Kodi; Zanardi, Odimar Zanuzo; Aguiar Santos, Kenia Fernanda; Yamamoto, Pedro Takao

    2017-02-01

    The impacts of six insect growth-regulators were assessed on the predator Ceraeochrysa cubana (Hagen) larvae and adults. Our results showed that diflubenzuron, lufenuron and pyriproxyfen caused 100% larva mortality, whereas buprofezin, methoxyfenozide and tebufenozide were similar to control treatment. In comparison to the control, buprofezin prolonged the duration of larval stage, while methoxyfenozide and tebufenozide reduced the predator larva development time. Buprofezin, methoxyfenozide and tebufenozide did not affect the C. cubana duration and survival of pupal stage, fecundity and fertility. However, methoxyfenozide and tebufenozide reduced predator female and male longevities. Based on a reduction coefficient, diflubenzuron, lufenuron and pyriproxyfen were highly harmful to first instar larvae, while buprofezin, methoxyfenozide and tebufenozide were considered slightly harmful to the predator. Estimating the life table parameters, our results showed that buprofezin, methoxyfenozide and tebufenozide reduced the C. cubana R o , r and λ. In comparison to the control, buprofezin prolonged the T and methoxyfenozide and tebufenozide shortened the predator T. In adults, our results showed that the insecticides did not cause significant mortality, but diflubenzuron, lufenuron and pyriproxyfen reduced the C. cubana fecundity and longevity. Diflubenzuron and lufenuron also reduced the C. cubana fertility. Based on a reduction coefficient, diflubenzuron and lufenuron were highly harmful to C. cubana adults, while pyriproxyfen was slightly harmful and buprofezin, methoxyfenozide and tebufenozide were considered harmless to the predator. Therefore, insect growth-regulators affect the C. cubana biological or populational parameters, and they can harm the integrated pest management programs that aim the predator conservation and/or augmentation in agroecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Disease Resistance in the Drywood Termite, Incisitermes schwarzi: Does Nesting Ecology Affect Immunocompetence?

    PubMed Central

    Calleri, Daniel V.; Rosengaus, Rebeca B.; Traniello, James F.A.

    2010-01-01

    Termites live in nests that can differ in microbial load and thus vary in degree of disease risk. It was hypothesized that termite investment in immune response would differ in species living in nest environments that vary in the richness and abundance of microbes. Using the drywood termite, Incisitermes schwarzi Banks (Isoptera: Kalotermitidae), as a model for species having low nest and cuticular microbial loads, the susceptibility of individuals and groups to conidia of the entomopathogenic fungus, Metarhizium anisopliae Sorokin (Hypocreales: Clavicipitaceae), was examined. The survivorship of I. schwarzi was compared to that of the dampwood termite, Zootermopsis angusticollis Hagen (Termopsidae), a species with comparatively high microbial loads. The results indicated that I. schwarzi derives similar benefits from group living as Z. angusticollis: isolated termites had 5.5 times the hazard ratio of death relative to termites nesting in groups of 25 while termites in groups of 10 did not differ significantly from the groups of 25. The results also indicated, after controlling for the influence of group size and conidia exposure on survivorship, that Z. angusticollis was significantly more susceptible to fungal infection than I. schwarzi, the former having 1.6 times the hazard ratio of death relative to drywood termites. Thus, disease susceptibility and individual investment in immunocompetence may not be dependent on interspecific variation in microbial pressures. The data validate prior studies indicating that sociality has benefits in infection control and suggest that social mechanisms of disease resistance, rather than individual physiological and immunological adaptations, may have been the principle target of selection related to variation in infection risk from microbes in the nest environment of different termite species. PMID:20572790

  9. Fifty years of the integrated control concept: moving the model and implementation forward in Arizona††

    PubMed Central

    Naranjo, Steven E; Ellsworth, Peter C

    2009-01-01

    Fifty years ago, Stern, Smith, van den Bosch and Hagen outlined a simple but sophisticated idea of pest control predicated on the complementary action of chemical and biological control. This integrated control concept has since been a driving force and conceptual foundation for all integrated pest management (IPM) programs. The four basic elements include thresholds for determining the need for control, sampling to determine critical densities, understanding and conserving the biological control capacity in the system and the use of selective insecticides or selective application methods, when needed, to augment biological control. Here we detail the development, evolution, validation and implementation of an integrated control (IC) program for whitefly, Bemisia tabaci (Genn.), in the Arizona cotton system that provides a rare example of the vision of Stern and his colleagues. Economic thresholds derived from research-based economic injury levels were developed and integrated with rapid and accurate sampling plans into validated decision tools widely adopted by consultants and growers. Extensive research that measured the interplay among pest population dynamics, biological control by indigenous natural enemies and selective insecticides using community ordination methods, predator:prey ratios, predator exclusion and demography validated the critical complementary roles played by chemical and biological control. The term ‘bioresidual’ was coined to describe the extended environmental resistance from biological control and other forces possible when selective insecticides are deployed. The tangible benefits have been a 70% reduction in foliar insecticides, a >$200 million saving in control costs and yield, along with enhanced utilization of ecosystem services over the last 14 years. Published in 2009 by John Wiley & Sons, Ltd. PMID:19834884

  10. Relationships between xylem vessel characteristics, calculated axial hydraulic conductance and size-controlling capacity of peach rootstocks

    PubMed Central

    Tombesi, Sergio; Johnson, R. Scott; Day, Kevin R.; DeJong, Theodore M.

    2010-01-01

    Background and Aims Previous studies indicate that the size-controlling capacity of peach rootstocks is associated with reductions of scion water potential during mid-day that are caused by the reduced hydraulic conductance of the rootstock. Thus, shoot growth appears to be reduced by decreases in stem water potential. The aim of this study was to investigate the mechanism of reduced hydraulic conductance in size-controlling peach rootstocks. Methods Anatomical measurements (diameter and frequency) of xylem vessels were determined in shoots, trunks and roots of three contrasting peach rootstocks grown as trees, each with different size-controlling characteristics: ‘Nemaguard’ (vigorous), ‘P30-135’ (intermediate vigour) and ‘K146-43’ (substantially dwarfing). Based on anatomical measurements, the theoretical axial xylem conductance of each tissue type and rootstock genotype was calculated via the Poiseuille–Hagen law. Key Results Larger vessel dimensions were found in the vigorous rootstock (‘Nemaguard’) than in the most dwarfing one (‘K146-43’) whereas vessels of ‘P30-135’ had intermediate dimensions. The density of vessels per xylem area in ‘Nemaguard’ was also less than in ‘P30-135’and ‘K146-43’. These characteristics resulted in different estimated hydraulic conductance among rootstocks: ‘Nemaguard’ had higher theoretical values followed by ‘P30-135’ and ‘K146-43’. Conclusions These data indicate that phenotypic differences in xylem anatomical characteristics of rootstock genotypes appear to influence hydraulic conductance capacity directly, and therefore may be the main determinant of dwarfing in these peach rootstocks. PMID:19939979

  11. Flow cells for bioanalytical and bioprocess applications with optimized dynamic response and flow characteristics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lancaster, V.R.; Modlin, D.N.

    1994-12-31

    In this study, the authors present a method for design and characterization of flow cells developed for minimum flow volume and optimal dynamic response with a given central observation area. The dynamic response of a circular shaped dual ported flow cell was compared to that obtained from a flow cell whose optimized shape was determined using this method. In the optimized flow cell design, the flow rate at the nominal operating pressure increased by 50% whereas the flow cell volume was reduced by 70%. In addition, the dynamic response of the new flow cell was found to be 200% fastermore » than the circular flow cell. The fluid dynamic analysis included simple graphical techniques utilizing free stream vorticity functions and Hagen-Poiseuille relationships. The flow cell dynamic response was measured using a fluorescence detection system. The fluoresce in emission from a 400{micro}m spot located at the exit port was measured as a function of time after switching the input to the flow cell between fluorescent and non-fluorescent solutions. Analysis of results revealed the system could be reasonably characterized as a first order dynamic system. Although some evidence of second order behavior was also observed, it is reasonable to assume that a first order model will provide adequate predictive capability for many real world applications. Given a set of flow cell requirements, the methods presented in this study can be used to design and characterize flow cells with lower reagent consumption and reduced purging times. These improvements can be readily translated into reduced process times and/or lower usage of high cost reagents.« less

  12. Effects of ring-porous and diffuse-porous stem wood anatomy on the hydraulic parameters used in a water flow and storage model.

    PubMed

    Steppe, Kathy; Lemeur, Raoul

    2007-01-01

    Calibration of a recently developed water flow and storage model based on experimental data for a young diffuse-porous beech tree (Fagus sylvatica L.) and a young ring-porous oak tree (Quercus robur L.) revealed that differences in stem wood anatomy between species strongly affect the calibrated values of the hydraulic model parameters. The hydraulic capacitance (C) of the stem storage tissue was higher in oak than in beech (939.8 versus 212.3 mg MPa(-1)). Model simulation of the elastic modulus (epsilon) revealed that this difference was linked to the higher elasticity of the stem storage tissue of oak compared with beech. Furthermore, the hydraulic resistance (R (x)) of beech was about twice that of oak (0.1829 versus 0.1072 MPa s mg(-1)). To determine the physiological meaning of the R (x) parameter identified by model calibration, we analyzed the stem wood anatomy of the beech and oak trees. Calculation of stem specific hydraulic conductivity (k (s)) of beech and oak with the Hagen-Poiseuille equation confirmed the differences in R (x) predicted by the model. The contributions of different vessel diameter classes to the total hydraulic conductivity of the xylem were calculated. As expected, the few big vessels contributed much more to total conductivity than the many small vessels. Compared with beech, the larger vessels of oak resulted in a higher k (s) (10.66 versus 4.90 kg m(-1) s(-1) MPa(-1)). The calculated ratio of k (s) of oak to beech was 2, confirming the R (x) ratio obtained by model calibration. Thus, validation of the R (x) parameter of the model led to identification of its physiological meaning.

  13. Changes in sapwood permeability and anatomy with tree age and height in the broad-leaved evergreen species Eucalyptus regnans.

    PubMed

    England, Jacqueline R; Attiwill, Peter M

    2007-08-01

    Increases in plant size and structural complexity with increasing age have important implications for water flow through trees. Water supply to the crown is influenced by both the cross-sectional area and the permeability of sapwood. It has been hypothesized that hydraulic conductivity within sapwood increases with age. We investigated changes in sapwood permeability (k) and anatomy with tree age and height in the broad-leaved evergreen species Eucalyptus regnans F. Muell. Sapwood was sampled at breast height from trees ranging from 8 to 240 years old, and at three height positions on the main stem of 8-year-old trees. Variation in k was not significant among sampling height positions in young trees. However, k at breast height increased with tree age. This was related to increases in both vessel frequency and vessel diameter, resulting in a greater proportion of sapwood being occupied by vessel lumina. Sapwood hydraulic conductivity (the product of k and sapwood area) also increased with increasing tree age. However, at the stand level, there was a decrease in forest sapwood hydraulic conductivity with increasing stand age, because of a decrease in the number of trees per hectare. Across all ages, there were significant relationships between k and anatomy, with individual anatomical characteristics explaining 33-62% of the variation in k. There was also strong agreement between measured k and permeability predicted by the Hagen-Poiseuille equation. The results support the hypothesis of an increase in sapwood permeability at breast height with age. Further measurements are required to confirm this result at other height positions in older trees. The significance of tree-level changes in sapwood permeability for stand-level water relations is discussed.

  14. Catathrenia: Parasomnia or Uncommon Feature of Sleep Disordered Breathing?

    PubMed Central

    Guilleminault, Christian; Hagen, Chad C.; Khaja, Aliuddin M

    2008-01-01

    Objective: We report a series of seven consecutive cases of catathrenia (sleep related groaning) that differ from limited previous reports in the literature with regard to sleep stage and response to treatment. Background: Catathrenia was recently defined as a parasomnia in the International Classification of Sleep Disorders Diagnostic and Coding Manual (ICSD-2), but there is debate about its classification, and its response to CPAP is unknown. Methods: We present 7 consecutive patients presenting with catathrenia over a 5-year period. They were all young women, ranging in age from 20 to 34 years with a body mass index (BMI) <25. They underwent standard clinical evaluation, questionnaires, physical exam, craniofacial evaluations, and nocturnal polysomnography. All seven were titrated on continuous passive airway pressure (CPAP) treatment for sleep disordered breathing then offered surgical treatment if unable to tolerate or adhere to CPAP recommendations. Results: Groaning was present throughout all stages of sleep. The mean (SD) AHI and RDI were 3.2 (0.56) and 13.1 (2.4) respectively. CPAP resolved groaning in all cases. 5 patients (71%) elected subsequent surgical intervention. Three of the 4 that followed up after surgery required adjuvant oral appliance treatment, but all four ultimately had resolution of groaning. Conclusions: Catathrenia may have subtypes related to sleep stage specificity or presence of sleep disordered breathing. In our heterogeneous group of non-obese women with a normal AHI and elevated RDI, CPAP and select soft tissue surgeries of the upper airway (often augmented with an oral appliance) successfully treated nocturnal groaning. Citation: Guilleminault C; Hagen CC; Khaja AM. Catathrenia: parasomnia or uncommon feature of sleep disordered breathing?. SLEEP 2008;31(1):132-139. PMID:18220087

  15. Re-examining overlap between tactile and visual motion responses within hMT+ and STS

    PubMed Central

    Jiang, Fang; Beauchamp, Michael S.; Fine, Ione

    2015-01-01

    Here we examine overlap between tactile and visual motion BOLD responses within the human MT+ complex. Although several studies have reported tactile responses overlapping with hMT+, many used group average analyses, leaving it unclear whether these responses were restricted to sub-regions of hMT+. Moreover, previous studies either employed a tactile task or passive stimulation, leaving it unclear whether or not tactile responses in hMT+ are simply the consequence of visual imagery. Here we carried out a replication of one of the classic papers finding tactile responses in hMT+ (Hagen et al. 2002). We mapped MT and MST in individual subjects using visual field localizers. We then examined responses to tactile motion on the arm, either presented passively or in the presence of a visual task performed at fixation designed to minimize visualization of the concurrent tactile stimulation. To our surprise, without a visual task, we found only weak tactile motion responses in MT (6% of voxels showing tactile responses) and MST (2% of voxels). With an unrelated visual task designed to withdraw attention from the tactile modality, responses in MST reduced to almost nothing (<1% regions). Consistent with previous results, we did observe tactile responses in STS regions superior and anterior to hMT+. Despite the lack of individual overlap, group averaged responses produced strong spurious overlap between tactile and visual motion responses within hMT+ that resembled those observed in previous studies. The weak nature of tactile responses in hMT+ (and their abolition by withdrawal of attention) suggests that hMT+ may not serve as a supramodal motion processing module. PMID:26123373

  16. Arabidopsis thaliana GH3.15 acyl acid amido synthetase has a highly specific substrate preference for the auxin precursor indole-3-butyric acid.

    PubMed

    Sherp, Ashley M; Westfall, Corey S; Alvarez, Sophie; Jez, Joseph M

    2018-03-23

    Various phytohormones control plant growth and development and mediate biotic and abiotic stress responses. Gretchen Hagen 3 (GH3) acyl acid amido synthetases are plant enzymes that typically conjugate amino acids to indole-3-acetic acid (IAA) or jasmonic acid (JA) to inactivate or activate these phytohormones, respectively; however, the physiological and biological roles of many of these enzymes remain unclear. Using a biochemical approach, we found that the Arabidopsis thaliana GH3.15 (AtGH3.15) preferentially uses indole-3-butyric acid (IBA) and glutamine as substrates. The X-ray crystal structure of the AtGH3.15·AMP complex, modeling of IBA in the active site, and biochemical analysis of site-directed mutants provide insight on active site features that lead to AtGH3.15's preference for IBA. Assay-based in planta analysis of AtGH3.15-overexpressing lines indicated that their root elongation and lateral root density were resistant to IBA treatment but not to treatment with either IAA or JA. These findings suggest that AtGH3.15 may play a role in auxin homeostasis by modulating the levels of IBA for peroxisomal conversion to IAA. Analysis of AtGH3.15 promoter-driven yellow fluorescent protein reporter lines revealed that AtGH3.15 is expressed at significant levels in seedlings, roots, and parts of the siliques. We conclude that AtGH3.15 is unique in the GH3 protein family for its role in modifying IBA in auxin homeostasis and that it is the first GH3 protein shown to primarily modify a plant growth regulator other than IAA and JA. © 2018 Sherp et al.

  17. Salix polaris growth responses to active layer detachment and solifluction processes in High Arctic.

    NASA Astrophysics Data System (ADS)

    Siekacz, Liliana

    2015-04-01

    The work is dedicated to demonstrate the potential of Salix polaris grow properties in the dendrogemorphologic image, analyzing periglacially induced slope processes in the high Arctic.. Observed anatomical and morphological plants responses to solifluction and active layer detachment processes are presented qualitatively and quantitatively as a summary of presented features frequency. The results are discussed against the background of the other research results in this field. The investigations was performed in Ebba valley, in the vicinity of Petunia Bay, northernmost part of Billefjorden in central Spitsbergen (Svalbard). Environmental conditions are characterized by annual precipitation sum lower than 200 mm (Hagen et al.,1993) and average summer temperature of about 5°C, with maximum daily temperatures rarely exceeding 10°C (Rachlewicz, 2009). Collected shrub material was prepared according to the methods presented by Schweingruber and Poschlod (2005). Thin (approx. 15-20μm) sections of the whole cross-section were prepared with a sledge microtome, stained with Safranine and Astra blue and finally permanently fixed on microslides with Canada balsam and dried. Snapshots were taken partially for each cross-section with digital camera (ColorView III, Olympus) connected to a microscope (Olympus BX41) and merged into one, high resolution image. After all, ring widths were measured in 3-4 radii in every single cross-section using ImageJ software. Analyzed plants revealed extremely harsh environmental conditions of their growth. Buchwał et al. (2013) provided quantitative data concerning missing rings and partially missing rings in shrubs growing on Ebba valley floor. Mean ring width at the level of 79μm represents one of the smallest values of yearly growth ever noted. The share of missing rings and partially missing rings was 11,2% and 13,6% respectively. Plants growing on Ebba valley slope indicate almost twice smaller values of ring width (41μm), and higher

  18. RTopo-2: A global high-resolution dataset of ice sheet topography, ice shelf cavity geometry and ocean bathymetry

    NASA Astrophysics Data System (ADS)

    Timmermann, Ralph; Schaffer, Janin

    2016-04-01

    The RTopo-1 data set of Antarctic ice sheet/shelf geometry and global ocean bathymetry has proven useful not only for modelling studies of ice-ocean interaction in the southern hemisphere. Following the spirit of this data set, we introduce a new product (RTopo-2) that contains consistent maps of global ocean bathymetry, upper and lower ice surface topographies for Greenland and Antarctica, and global surface height on a spherical grid with now 30 arc seconds resolution. We used the General Bathymetric Chart of the Oceans (GEBCO_2014) as the backbone and added the International Bathymetric Chart of the Arctic Ocean version 3 (IBCAOv3) and the International Bathymetric Chart of the Southern Ocean (IBCSO) version 1. To achieve a good representation of the fjord and shelf bathymetry around the Greenland continent, we corrected data from earlier gridded products in the areas of Petermann Glacier, Hagen Bræ and Helheim Glacier assuming that sub-ice and fjord bathymetries roughly follow plausible Last Glacial Maximum ice flow patterns. For the continental shelf off northeast Greenland and the floating ice tongue of Nioghalvfjerdsfjorden Glacier at about 79°N, we incorporated a high-resolution digital bathymetry model including all available multibeam survey data for the region. Radar data for ice surface and ice base topographies of the floating ice tongues of Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm have been obtained from the data centers of Technical University of Denmark (DTU), Operation Icebridge (NASA/NSF) and Alfred Wegener Institute (AWI). For the Antarctic ice sheet/ice shelves, RTopo-2 largely relies on the Bedmap-2 product but applies corrections for the geometry of Getz, Abbot and Fimbul ice shelf cavities. The data set is available in full and in regional subsets in NetCDF format from the PANGAEA database.

  19. Genome-wide analysis of the GH3 family in apple (Malus × domestica)

    PubMed Central

    2013-01-01

    Background Auxin plays important roles in hormone crosstalk and the plant’s stress response. The auxin-responsive Gretchen Hagen3 (GH3) gene family maintains hormonal homeostasis by conjugating excess indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acids (JAs) to amino acids during hormone- and stress-related signaling pathways. With the sequencing of the apple (Malus × domestica) genome completed, it is possible to carry out genomic studies on GH3 genes to indentify candidates with roles in abiotic/biotic stress responses. Results Malus sieversii Roem., an apple rootstock with strong drought tolerance and the ancestral species of cultivated apple species, was used as the experimental material. Following genome-wide computational and experimental identification of MdGH3 genes, we showed that MdGH3s were differentially expressed in the leaves and roots of M. sieversii and that some of these genes were significantly induced after various phytohormone and abiotic stress treatments. Given the role of GH3 in the negative feedback regulation of free IAA concentration, we examined whether phytohormones and abiotic stresses could alter the endogenous auxin level. By analyzing the GUS activity of DR5::GUS-transformed Arabidopsis seedlings, we showed that ABA, SA, salt, and cold treatments suppressed the auxin response. These findings suggest that other phytohormones and abiotic stress factors might alter endogenous auxin levels. Conclusion Previous studies showed that GH3 genes regulate hormonal homeostasis. Our study indicated that some GH3 genes were significantly induced in M. sieversii after various phytohormone and abiotic stress treatments, and that ABA, SA, salt, and cold treatments reduce the endogenous level of axuin. Taken together, this study provides evidence that GH3 genes play important roles in the crosstalk between auxin, other phytohormones, and the abiotic stress response by maintaining auxin homeostasis. PMID:23638690

  20. Dynamic regulation of auxin oxidase and conjugating enzymes AtDAO1 and GH3 modulates auxin homeostasis

    PubMed Central

    Mellor, Nathan; Band, Leah R.; Pěnčík, Aleš; Rashed, Afaf; Holman, Tara; Wilson, Michael H.; Voß, Ute; Bishopp, Anthony; King, John R.

    2016-01-01

    The hormone auxin is a key regulator of plant growth and development, and great progress has been made understanding auxin transport and signaling. Here, we show that auxin metabolism and homeostasis are also regulated in a complex manner. The principal auxin degradation pathways in Arabidopsis include oxidation by Arabidopsis thaliana gene DIOXYGENASE FOR AUXIN OXIDATION 1/2 (AtDAO1/2) and conjugation by Gretchen Hagen3s (GH3s). Metabolic profiling of dao1-1 root tissues revealed a 50% decrease in the oxidation product 2-oxoindole-3-acetic acid (oxIAA) and increases in the conjugated forms indole-3-acetic acid aspartic acid (IAA-Asp) and indole-3-acetic acid glutamic acid (IAA-Glu) of 438- and 240-fold, respectively, whereas auxin remains close to the WT. By fitting parameter values to a mathematical model of these metabolic pathways, we show that, in addition to reduced oxidation, both auxin biosynthesis and conjugation are increased in dao1-1. Transcripts of AtDAO1 and GH3 genes increase in response to auxin over different timescales and concentration ranges. Including this regulation of AtDAO1 and GH3 in an extended model reveals that auxin oxidation is more important for auxin homoeostasis at lower hormone concentrations, whereas auxin conjugation is most significant at high auxin levels. Finally, embedding our homeostasis model in a multicellular simulation to assess the spatial effect of the dao1-1 mutant shows that auxin increases in outer root tissues in agreement with the dao1-1 mutant root hair phenotype. We conclude that auxin homeostasis is dependent on AtDAO1, acting in concert with GH3, to maintain auxin at optimal levels for plant growth and development. PMID:27651495

  1. Dynamic regulation of auxin oxidase and conjugating enzymes AtDAO1 and GH3 modulates auxin homeostasis.

    PubMed

    Mellor, Nathan; Band, Leah R; Pěnčík, Aleš; Novák, Ondřej; Rashed, Afaf; Holman, Tara; Wilson, Michael H; Voß, Ute; Bishopp, Anthony; King, John R; Ljung, Karin; Bennett, Malcolm J; Owen, Markus R

    2016-09-27

    The hormone auxin is a key regulator of plant growth and development, and great progress has been made understanding auxin transport and signaling. Here, we show that auxin metabolism and homeostasis are also regulated in a complex manner. The principal auxin degradation pathways in Arabidopsis include oxidation by Arabidopsis thaliana gene DIOXYGENASE FOR AUXIN OXIDATION 1/2 (AtDAO1/2) and conjugation by Gretchen Hagen3s (GH3s). Metabolic profiling of dao1-1 root tissues revealed a 50% decrease in the oxidation product 2-oxoindole-3-acetic acid (oxIAA) and increases in the conjugated forms indole-3-acetic acid aspartic acid (IAA-Asp) and indole-3-acetic acid glutamic acid (IAA-Glu) of 438- and 240-fold, respectively, whereas auxin remains close to the WT. By fitting parameter values to a mathematical model of these metabolic pathways, we show that, in addition to reduced oxidation, both auxin biosynthesis and conjugation are increased in dao1-1 Transcripts of AtDAO1 and GH3 genes increase in response to auxin over different timescales and concentration ranges. Including this regulation of AtDAO1 and GH3 in an extended model reveals that auxin oxidation is more important for auxin homoeostasis at lower hormone concentrations, whereas auxin conjugation is most significant at high auxin levels. Finally, embedding our homeostasis model in a multicellular simulation to assess the spatial effect of the dao1-1 mutant shows that auxin increases in outer root tissues in agreement with the dao1-1 mutant root hair phenotype. We conclude that auxin homeostasis is dependent on AtDAO1, acting in concert with GH3, to maintain auxin at optimal levels for plant growth and development.

  2. Review of the millipede family Opisotretidae (Diplopoda, Polydesmida), with descriptions of new species

    PubMed Central

    Golovatch, Sergei I.; Geoffroy, Jean-Jacques; Stoev, Pavel; Spiegel, Didier Vanden

    2013-01-01

    Abstract The small, basically Oriental family Opisotretidae is rediagnosed, reclassified, and shown to comprise the following seven genera, all keyed: Carlotretus Hoffman, 1980, with two species, including Carlotretus triramus sp. n. from southern China; Corypholophus Attems, 1938, with two species, one in Vietnam, the other in the Ryukyus, Japan; Martensodesmus Golovatch, 1987, with eight species, all keyed, including Martensodesmus cattienensis sp. n. from southern Vietnam, as well as Martensodesmus bedosae sp. n. and Martensodesmus spiniger sp. n. from southern China; Opisotretus Attems, 1907, with seven species, all keyed, including Opisotretus beroni sp. n. and Opisotretus hagen sp. n., both from Papua New Guinea, Opisotretus deharvengi sp. n. from Sulawesi, Indonesia, and Opisotretus spinosus sp. n. from Nusakambangan Island, off Java, Indonesia; Opisthoporodesmus Silvestri, 1899, with six nominate species; Retrodesmus Chamberlin, 1945, with two species, i.e. the type-species Retrodesmus dammermani Chamberlin, 1945, from Java, Indonesia, revised from the holotype, and Retrodesmus cavernicola sp. n., from Papua New Guinea; and Solaenaulus Attems, 1940, with two species. Comments are presented on the family’s possible relationships and palaeogeographic history. Instead of being considered as the sole component of the superfamily Opisotretoidea, the Opisotretidae is believed here to form one of the families of the diverse superfamily Trichopolydesmoidea, perhaps the sister-group to, if not immediately derived from, the pantropical family Fuhrmannodesmidae. The origin of Opisotretidae, previously dated as far back as the Triassic (220 Ma) in relation to the fragmentation of eastern Gondwanaland, mainly in the region of present-day Indonesia, could have had nothing to do with Gondwanaland. Opisotretids might have originated in mainland Southeast Asia well within the Cenozoic, with subsequent dispersals along the Himalayas in the West and across Indonesia

  3. Genome-wide analysis of the GH3 family in apple (Malus × domestica).

    PubMed

    Yuan, Huazhao; Zhao, Kai; Lei, Hengjiu; Shen, Xinjie; Liu, Yun; Liao, Xiong; Li, Tianhong

    2013-05-02

    Auxin plays important roles in hormone crosstalk and the plant's stress response. The auxin-responsive Gretchen Hagen3 (GH3) gene family maintains hormonal homeostasis by conjugating excess indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acids (JAs) to amino acids during hormone- and stress-related signaling pathways. With the sequencing of the apple (Malus × domestica) genome completed, it is possible to carry out genomic studies on GH3 genes to indentify candidates with roles in abiotic/biotic stress responses. Malus sieversii Roem., an apple rootstock with strong drought tolerance and the ancestral species of cultivated apple species, was used as the experimental material. Following genome-wide computational and experimental identification of MdGH3 genes, we showed that MdGH3s were differentially expressed in the leaves and roots of M. sieversii and that some of these genes were significantly induced after various phytohormone and abiotic stress treatments. Given the role of GH3 in the negative feedback regulation of free IAA concentration, we examined whether phytohormones and abiotic stresses could alter the endogenous auxin level. By analyzing the GUS activity of DR5::GUS-transformed Arabidopsis seedlings, we showed that ABA, SA, salt, and cold treatments suppressed the auxin response. These findings suggest that other phytohormones and abiotic stress factors might alter endogenous auxin levels. Previous studies showed that GH3 genes regulate hormonal homeostasis. Our study indicated that some GH3 genes were significantly induced in M. sieversii after various phytohormone and abiotic stress treatments, and that ABA, SA, salt, and cold treatments reduce the endogenous level of axuin. Taken together, this study provides evidence that GH3 genes play important roles in the crosstalk between auxin, other phytohormones, and the abiotic stress response by maintaining auxin homeostasis.

  4. Final Progress Report: Developing Ethical Practices for Genetics Testing in the Workplace

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Laura Roberts, MD; Teddy Warner, PhD

    Our multidisciplinary research team for this project involved collaboration between the Department of Psychiatry and Behavioral Medicine at the Medical College of Wisconsin (MCW) and the Department of Family and Community Medicine at the University of New Mexico Health Sciences Center (UNM HSC). Our research team in Wisconsin was led by Laura Roberts, M.D., Principal Investigator, and included Scott Helberg, MLS (Project Coordinator), Kate Green Hammond, Ph.D. (Consultant), Krisy Edenharder (Research Coordinator), and Mark Talatzko (Research Assistant). Our New Mexico-based team was led by Teddy Warner, Ph.D., Co-Principal Investigator and UNM Site Principal Investigator, and included Suzanne Roybal (Project Assistant),more » Darlyn Mabon (Project Assistant), Kate Green Hammond, PhD (Senior Research Scientist on the UNM team from 2004 until January, 2007), and Paulette Christopher (Research Assistant). In addition, computer technical and web support for the web-based survey conducted on a secure server at the University of New Mexico was provided by Kevin Wiley and Kim Hagen of the Systems and Programming Team of the Health Sciences Center Library and Information Center. We stated 3 aims in the grant proposal: (1) To collect web survey reports of the ethical perspectives, concerns, preferences and decision-making related to genetic testing using surveys from employees at: (a) Los Alamos National Laboratory (LANL); (b) Sandia National Laboratories (SNL); and (c) the University of New Mexico Health Sciences Center (UNMHSC); (2) To perform an extensive literature search and the extant survey data to develop evidence-based policy recommendations for ethically sound genetic testing associated with research and occupational health activities in the workplace; and, (3) To host a conference at the Medical College of Wisconsin to provide employers, workers, health professionals, researchers, the public, and the media an opportunity to consider ethical issues involved in

  5. Acyl substrate preferences of an IAA-amido synthetase account for variations in grape (Vitis vinifera L.) berry ripening caused by different auxinic compounds indicating the importance of auxin conjugation in plant development

    PubMed Central

    Böttcher, Christine; Boss, Paul K.; Davies, Christopher

    2011-01-01

    Nine Gretchen Hagen (GH3) genes were identified in grapevine (Vitis vinifera L.) and six of these were predicted on the basis of protein sequence similarity to act as indole-3-acetic acid (IAA)-amido synthetases. The activity of these enzymes is thought to be important in controlling free IAA levels and one auxin-inducible grapevine GH3 protein, GH3-1, has previously been implicated in the berry ripening process. Ex planta assays showed that the expression of only one other GH3 gene, GH3-2, increased following the treatment of grape berries with auxinic compounds. One of these was the naturally occurring IAA and the other two were synthetic, α-naphthalene acetic acid (NAA) and benzothiazole-2-oxyacetic acid (BTOA). The determination of steady-state kinetic parameters for the recombinant GH3-1 and GH3-2 proteins revealed that both enzymes efficiently conjugated aspartic acid (Asp) to IAA and less well to NAA, while BTOA was a poor substrate. GH3-2 gene expression was induced by IAA treatment of pre-ripening berries with an associated increase in levels of IAA-Asp and a decrease in free IAA levels. This indicates that GH3-2 responded to excess auxin to maintain low levels of free IAA. Grape berry ripening was not affected by IAA application prior to veraison (ripening onset) but was considerably delayed by NAA and even more so by BTOA. The differential effects of the three auxinic compounds on berry ripening can therefore be explained by the induction and acyl substrate specificity of GH3-2. These results further indicate an important role for GH3 proteins in controlling auxin-related plant developmental processes. PMID:21543520

  6. [Effect of physical properties of respiratory gas on pneumotachographic measurement of ventilation in newborn infants].

    PubMed

    Foitzik, B; Schmalisch, G; Wauer, R R

    1994-04-01

    The measurement of ventilation in neonates has a number of specific characteristics; in contrast to lung function testing in adults, the inspiratory gas for neonates is often conditioned. In pneumotachographs (PNT) based on Hagen-Poiseuille's law, changes in physical characteristics of respiratory gas (temperature, humidity, pressure and oxygen fraction [FiO2]) produce a volume change as calculated with the ideal gas equation p*V/T = const; in addition, the viscosity of the gas is also changed, thus leading to measuring errors. In clinical practice, the effect of viscosity on volume measurement is often ignored. The accuracy of these empirical laws was investigated in a size 0 Fleisch-PNT using a flow-through technique and variously processed respiratory gas. Spontaneous breathing was simulated with the aid of a calibration syringe (20 ml) and a rate of 30 min-1. The largest change in viscosity (11.6% at 22 degrees C and dry gas) is found with an increase in FiO2 (21...100%). A rise in temperature from 24 to 35 degrees C (dry air) produced an increase in viscosity of 5.2%. An increase of humidity (0...90%, 35 degrees C) decreased the viscosity by 3%. A partial compensation of these viscosity errors is thus possible. Pressure change (0...50 mbar, under ambient conditions) caused no measurable viscosity error. With the exception of temperature, the measurements have shown good agreement between the measured volume measuring errors and those calculated from viscosity changes. If the respiratory gas differs from ambient air (e.g. elevated FiO2) or if the PNT is calibrated under BTPS conditions, changes in viscosity must not be neglected when performing accurate ventilation measurements. On the basis of the well-known physical laws of Dalton, Thiesen and Sutherland, a numerical correction of adequate accuracy is possible.

  7. Acyl substrate preferences of an IAA-amido synthetase account for variations in grape (Vitis vinifera L.) berry ripening caused by different auxinic compounds indicating the importance of auxin conjugation in plant development.

    PubMed

    Böttcher, Christine; Boss, Paul K; Davies, Christopher

    2011-08-01

    Nine Gretchen Hagen (GH3) genes were identified in grapevine (Vitis vinifera L.) and six of these were predicted on the basis of protein sequence similarity to act as indole-3-acetic acid (IAA)-amido synthetases. The activity of these enzymes is thought to be important in controlling free IAA levels and one auxin-inducible grapevine GH3 protein, GH3-1, has previously been implicated in the berry ripening process. Ex planta assays showed that the expression of only one other GH3 gene, GH3-2, increased following the treatment of grape berries with auxinic compounds. One of these was the naturally occurring IAA and the other two were synthetic, α-naphthalene acetic acid (NAA) and benzothiazole-2-oxyacetic acid (BTOA). The determination of steady-state kinetic parameters for the recombinant GH3-1 and GH3-2 proteins revealed that both enzymes efficiently conjugated aspartic acid (Asp) to IAA and less well to NAA, while BTOA was a poor substrate. GH3-2 gene expression was induced by IAA treatment of pre-ripening berries with an associated increase in levels of IAA-Asp and a decrease in free IAA levels. This indicates that GH3-2 responded to excess auxin to maintain low levels of free IAA. Grape berry ripening was not affected by IAA application prior to veraison (ripening onset) but was considerably delayed by NAA and even more so by BTOA. The differential effects of the three auxinic compounds on berry ripening can therefore be explained by the induction and acyl substrate specificity of GH3-2. These results further indicate an important role for GH3 proteins in controlling auxin-related plant developmental processes.

  8. Is trabecular bone permeability governed by molecular ordering-induced fluid viscosity gain? Arguments from re-evaluation of experimental data in the framework of homogenization theory.

    PubMed

    Abdalrahman, T; Scheiner, S; Hellmich, C

    2015-01-21

    It is generally agreed on that trabecular bone permeability, a physiologically important quantity, is governed by the material׳s (vascular or intertrabecular) porosity as well as by the viscosity of the pore-filling fluids. Still, there is less agreement on how these two key factors govern bone permeability. In order to shed more light onto this somewhat open issue, we here develop a random homogenization scheme for upscaling Poiseuille flow in the vascular porosity, up to Darcy-type permeability of the overall porous medium "trabecular bone". The underlying representative volume element of the macroscopic bone material contains two types of phases: a spherical, impermeable extracellular bone matrix phase interacts with interpenetrating cylindrical pore channel phases that are oriented in all different space directions. This type of interaction is modeled by means of a self-consistent homogenization scheme. While the permeability of the bone matrix equals to zero, the permeability of the pore phase is found through expressing the classical Hagen-Poiseuille law for laminar flow in the format of a "micro-Darcy law". The upscaling scheme contains pore size and porosity as geometrical input variables; however, they can be related to each other, based on well-known relations between porosity and specific bone surface. As two key results, validated through comprehensive experimental data, it appears (i) that the famous Kozeny-Carman constant (which relates bone permeability to the cube of the porosity, the square of the specific surface, as well as to the bone fluid viscosity) needs to be replaced by an again porosity-dependent rational function, and (ii) that the overall bone permeability is strongly affected by the pore fluid viscosity, which, in case of polarized fluids, is strongly increased due to the presence of electrically charged pore walls. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Advantageous new conic cannula for spine cement injection.

    PubMed

    González, Sergio Gómez; Vlad, María Daniela; López, José López; Aguado, Enrique Fernández

    2014-09-01

    Experimental study to characterize the influence of the cannula geometry on both, the pressure drop and the cement flow velocity established along the cannula. To investigate how the new experimental geometry of cannulas can affect the extravertebral injection pressure and the velocity profiles established along the cannula during the injection process. Vertebroplasty procedure is being used to treat vertebral compression fractures. Vertebra infiltration is favored by the use of suitable: (1) syringes or injector devices; (2) polymer or ceramic bone cements; and (3) cannulas. However, the clinical use of ceramic bone cement has been limited due to press-filtering problems. Thus, new approaches concerning the cannula geometry are needed to minimize the press-filtering of calcium phosphate-based bone cements and thereby broaden its possible applications. Straight, conic, and combined conic-straight new cannulas with different proximal and distal both length and diameter ratios were drawn with computer-assisted design software. The new geometries were theoretically analyzed by: (1) Hagen-Poisseuille law; and (2) computational fluid dynamics. Some experimental models were manufactured and tested for extrusion in order to confirm and further advance the theoretical results. The results confirm that the totally conic cannula model, having proximal to distal diameter ratio equal 2, requires the lowest injection pressure. Furthermore, its velocity profile showed no discontinuity at all along the cannula length, compared with other known combined proximal and distal straight cannulas, where discontinuity was produced at the proximal-distal transition zone. The conclusion is that the conic cannulas: (a) further reduced the extravertebral pressure during the injection process; (b) showed optimum fluid flow velocity profiles to minimize filter-pressing problems, especially when ceramic cements are used; and (c) can be easily manufactured. In this sense, the new conic cannulas

  10. Colony Size Affects the Efficacy of Bait Containing Chlorfluazuron Against the Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

    PubMed

    Lee, Ching-Chen; Neoh, Kok-Boon; Lee, Chow-Yang

    2014-12-01

    The efficacy of chitin synthesis inhibitors (CSIs) against fungus-growing termites is known to vary. In this study, 0.1% chlorfluazuron (CFZ) cellulose bait was tested against medium and large field colonies of Macrotermes gilvus (Hagen). The termite mounds were dissected to determine the health of the colony. Individual termites (i.e., workers and larvae) and fungus combs were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to detect the presence of CFZ. In this study, 540.0 ± 25.8 g (or equivalent to 540.0 ± 25.8 mg active ingredient) and 680.0 ± 49.0 g (680.0 ± 49.0 mg active ingredient) of bait matrix were removed by the medium- and large-sized colonies, respectively, after baiting. All treated medium-sized colonies were moribund. The dead termites were scattered in the mound, larvae were absent, population size had decreased by 90%, and the queens appeared unhealthy. In contrast, no or limited effects were found in large-sized colonies. Only trace amounts of CFZ were detected in workers, larvae, and fungus combs, and the population of large-sized colonies had declined by only up to 40%. This might be owing to the presence of large amount of basidiomycete fungus and a drastic decrease of CFZ content per unit fungus comb (a main food source of larvae) in the large-sized colonies, and hence reduced the toxic effect and longer time is required to accumulate the lethal dose in larvae. Nevertheless, we do not deny the possibility of CSI bait eliminating or suppressing the higher termite if the test colonies could pick up adequate lethal dose by installing more bait stations and prolonging the baiting period. © 2014 Entomological Society of America.

  11. A Laboratory Maintenance Regime for a Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

    PubMed

    Lee, Ching-Chen; Lee, Chow-Yang

    2015-06-01

    The optimum maintenance conditions of the fungus-growing termite, Macrotermes gilvus (Hagen) (Blattodea: Termitidae), in the laboratory were studied. Termites were kept on a matrix of moist sand and with fungus comb as food. The survival of groups of termites was measured when maintained at different population densities by changing group size and container volume. Larger groups (≥0.6 g) were more vigorous and had significant higher survival rates than smaller groups (≤0.3 g). The population density for optimal survival of M. gilvus is 0.0025 g per container volume (ml) or 0.0169 g per matrix volume (cm(3)), i.e., 1.2 g of termites kept in a 480-ml container filled with 71 cm3 of sand. In termite groups of smaller size (i.e., 0.3 g) or groups maintained in smaller container (i.e., 100 ml) the fungus comb was overgrown with Xylaria spp., and subsequently all termites died within the study period. The insufficient number of workers for regulating the growth of unwanted fungi other than Termitomyces spp. in the fungus comb is the most likely reason. Unlike some other mound-building termite species, M. gilvus showed satisfactory survival when maintained in non-nutritious matrix (i.e., sand). There was no significant difference in the survival rate between different colonies of M. gilvus (n=5), with survival in the range of 78.5-84.4% after 4 wk. Advances in the maintenance of Macrotermes will enable researchers to study with more biological relevance many aspects of the biology, behavior, and management of this species. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Diets, equipment, and techniques for maintaining crawfish in the laboratory

    USGS Publications Warehouse

    Tarshis, I.B.; Avault, James W.

    1978-01-01

    One commercial and 4 laboratory prepared extruded, water-stable diets were fed 3 times a week in 1-g portions to juvenile male and female White River crawfish, Procambarus acutus acutus (Girard), for 10 weeks. The. binding material in the laboratory preparation was alginate (Kelgin), whereas that in the commercial preparation was starch. No statistically significant weight differences developed between the groups of crawfish at the end of the 10-week period; all 5 diets were found satisfactory for feeding and maintaining P. acutus acutus in the laboratory, and all test crawfish survived throughout the experimental period. Weight gains were highest in a diet containing 50.5% protein; intermediate in those fed a diet with 46.0% protein; and lowest in those fed diets with 31.7 or 36.3% protein. Crawfish fed the commercial preparation of one of the 46.0% protein diets showed a slightly but not significantly higher weight gain than those fed the laboratory preparation of the diet. In an evaluation of the water stability of 5 commercially prepared animal chow diets and the commercial extruded diet, 2 of the commercial diets disintegrated after one hour exposure in water and the other 3 became bloated after one hour and remained on the surface throughout the 24-hour test. The commercial extruded diet maintained its water stability for the full 24 hours. The commercial preparation of the 46.0% protein diet was successfully used under laboratory conditions for feeding and maintaining the following crawfishes: Cambarellus shufeldtii (Faxon), Cambarus acuminatus Faxon, Orconectes limosus (Rafinesque), O. virilis (Hagen), Procambarus clarkii (Girard), and P. spiculifer (Le conte). In longevity experiments Cambarus diogenes diogenes Girard and Procambarus hinei (Ortmann) now have survived for 8 months on this diet in the laboratory.

  13. Very high precision and accuracy analysis of triple isotopic ratios of water. A critical instrumentation comparison study.

    NASA Astrophysics Data System (ADS)

    Gkinis, Vasileios; Holme, Christian; Morris, Valerie; Thayer, Abigail Grace; Vaughn, Bruce; Kjaer, Helle Astrid; Vallelonga, Paul; Simonsen, Marius; Jensen, Camilla Marie; Svensson, Anders; Maffrezzoli, Niccolo; Vinther, Bo; Dallmayr, Remi

    2017-04-01

    We present a performance comparison study between two state of the art Cavity Ring Down Spectrometers (Picarro L2310-i, L2140-i). The comparison took place during the Continuous Flow Analysis (CFA) campaign for the measurement of the Renland ice core, over a period of three months. Instant and complete vaporisation of the ice core melt stream, as well as of in-house water reference materials is achieved by accurate control of microflows of liquid into a homemade calibration system by following simple principles of the Hagen-Poiseuille law. Both instruments share the same vaporisation unit in a configuration that minimises sample preparation discrepancies between the two analyses. We describe our SMOW-SLAP calibration and measurement protocols for such a CFA application and present quality control metrics acquired during the full period of the campaign on a daily basis. The results indicate an unprecedented performance for all 3 isotopic ratios (δ2H, δ17O, δ18O ) in terms of precision, accuracy and resolution. We also comment on the precision and accuracy of the second order excess parameters of HD16O and H217O over H218O (Dxs, Δ17O ). To our knowledge these are the first reported CFA measurements at this level of precision and accuracy for all three isotopic ratios. Differences on the performance of the two instruments are carefully assessed during the measurement and reported here. Our quality control protocols extend to the area of low water mixing ratios, a regime in which often atmospheric vapour measurements take place and Cavity Ring Down Analysers show a poorer performance due to the lower signal to noise ratios. We address such issues and propose calibration protocols from which water vapour isotopic analyses can benefit from.

  14. Magnitude and Uncertainty of Carbon Pools and Fluxes in the US Forests

    NASA Astrophysics Data System (ADS)

    Harris, N.; Saatchi, S. S.; Fore, A.; Yu, Y.; Woodall, C. W.; Ganguly, S.; Nemani, R. R.; Hagen, S.; Birdsey, R.; Brown, S.; Salas, W.; Johnson, K. D.

    2015-12-01

    Sassan Saatchi1,2, Stephan Hagen3, Christopher Woodall4 , Sangram Ganguly,5 Nancy Harris6, Sandra Brown7, Timothy Pearson7, Alexander Fore1, Yifan Yu1, Rama Nemani5, Gong Zhang5, William Salas4, Roger Cooke81 NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA2 Institute of Environment and Sustainability, University of California, Los Angeles, CA, 90095, USA3 Applied Geosolutions, 55 Main Street Suit 125, Newmarket, NH 03857, USA4 USDA Forest Service, Northern Research Station, Saint Paul, MN 55108, USA5 NASA Ames Research Center, Moffett Field, CA 94035, USA6 Forests Program, World Resources Institute, Washington, DC, 20002, USA7 Winrock International, Ecosystem Services Unit, Arlington, VA 22202, USA8 Risk Analysis Resources for the Future, Washington DC 20036-1400Assessment of the carbon sinks and sources associated with greenhouse gas (GHG) fluxes across the US forestlands is a priority of the national climate mitigation policy. However, estimates of fluxes from the land sector are less precise compared to other sectors because of the large sources of uncertainty in quantifying the carbon pools, emissions, and removals associated with anthropogenic (land use) and natural changes in the US forestlands. As part of the NASA's Carbon Monitoring System, we developed a methodology based on a combination of ground inventory and space observations to develop spatially refined carbon pools and fluxes including the gross emissions and sequestration of carbon at each 1-ha land unit across the forestlands in the continental United States (CONUS) for the period of 2006-2010. Here, we provide the magnitude and uncertainty of multiple pools and fluxes of the US forestlands and outline the observational requirements to reduce the uncertainties for developing national climate mitigation policies based on the carbon sequestration capacity of the US forest lands. Keywords: forests, carbon pools, greenhouse gas, land use, attribution

  15. Intereruptive deformation at Three Sisters volcano, Oregon, USA: a strategy for traking volume changes through coupled hydraulic-viscoelastic modeling

    NASA Astrophysics Data System (ADS)

    Charco, M.; Rodriguez Molina, S.; Gonzalez, P. J.; Negredo, A. M.; Poland, M. P.; Schmidt, D. A.

    2017-12-01

    The Three Sisters volcanic region Oregon (USA) is one of the most active volcanic areas in the Cascade Range and is densely populated with eruptive vents. An extensive area just west of South Sister volcano has been actively uplifting since about 1998. InSAR data from 1992 through 2001 showed an uplift rate in the area of 3-4 cm/yr. Then the deformation rate considerably decreased between 2004 and 2006 as shown by both InSAR and continuous GPS measurements. Once magmatic system geometry and location are determined, a linear inversion of all GPS and InSAR data available is performed in order to estimate the volume changes of the source along the analyzed time interval. For doing so, we applied a technique based on the Truncated Singular Value Decomposition (TSVD) of the Green's function matrix representing the linear inversion. Here, we develop a strategy to provide a cut-off for truncation removing the smallest singular values without too much loose of data resolution against the stability of the method. Furthermore, the strategy will give us a quantification of the uncertainty of the volume change time series. The strength of the methodology resides in allowing the joint inversion of InSAR measurements from multiple tracks with different look angles and three component GPS measurements from multiple sites.Finally, we analyze the temporal behavior of the source volume changes using a new analytical model that describes the process of injecting magma into a reservoir surrounded by a viscoelastic shell. This dynamic model is based on Hagen-Poiseuille flow through a vertical conduit that leads to an increase in pressure within a spherical reservoir and time-dependent surface deformation. The volume time series are compared to predictions from the dynamic model to constrain model parameters, namely characteristic Poiseuille and Maxwell time scales, inlet and outlet injection pressure, and source and shell geometries. The modeling approach used here could be used to

  16. Stokes Approach to Preferential Flow at the Darcy-Scale

    NASA Astrophysics Data System (ADS)

    Germann, Peter; Bogner, Christina

    2017-04-01

    Preferential Flow in soils is fast, limited to infiltration and occupies but a small portion of porosity. However, how fast is it, how much water is involved, what is its flow rate, and how far is it carried? Supported with numerous measurements a Stokes approach to preferential flow provides the answers at the operational Darcy-scale. The approach to preferential flow in permeable media (pm) stresses momentum dissipation during viscous flow. Thus, a laminar water film percolates through a pm. The dynamic film is initially determined by the thickness F (m) and the specific contact area L (m2 m-3) per unit volume of the medium. Input to the medium's surface is a pulse with volume flux density q (ms-1) that starts and ends at times TB and TE. A specific pulse and the intrinsic properties of a pm determine F and L. A water content wave (WCW) envelops the spatio-temporal evolution of a water film. A WCW is completely described with a set of analytical relationships that are based on F, L, and the water's viscosity. The approach is an extension of Hagen-Poiseuille's law of flow in concentric conduits. It also evolves seamlessly from extending Darcy's law into non-saturated pm. Experimental determination of F and L follows either from drainage flow or from rapid soil moisture recordings during the passing of a WCW, for instance, with TDR-equipment. Parameters from numerous infiltration experiments in the field, in soil columns, in sand boxes, and lysimeters demonstrate the approach's broad applicability, thus framing the spatio-temporal extensions, velocities and volume flux densities of preferential flows. The specific contact area L is considered the locus of water, heat, particle and solute transfer between a WCW and the sessile parts of a pm. A recent analysis of delayed Br-breakthrough with respect to drainage flow supports the feasibility of the Stokes approach to preferential flow at the Darcy-scale. A perspective of modeling sequences of input pulses will

  17. Genome-wide identification and transcriptional profiling analysis of auxin response-related gene families in cucumber

    PubMed Central

    2014-01-01

    Background Auxin signaling has a vital function in the regulation of plant growth and development, both which are known to be mediated by auxin-responsive genes. So far, significant progress has been made toward the identification and characterization of auxin-response genes in several model plants, while no systematic analysis for these families was reported in cucumber (Cucumis sativus L.), a reference species for Cucurbitaceae crops. The comprehensive analyses will help design experiments for functional validation of their precise roles in plant development and stress responses. Results A genome-wide search for auxin-response gene homologues identified 16 auxin-response factors (ARFs), 27 auxin/indole acetic acids (Aux/IAAs), 10 Gretchen Hagen 3 (GH3s), 61 small auxin-up mRNAs (SAURs), and 39 lateral organ boundaries (LBDs) in cucumber. Sequence analysis together with the organization of putative motifs indicated the potential diverse functions of these five auxin-related family members. The distribution and density of auxin response-related genes on chromosomes were not uniform. Evolutionary analysis showed that the chromosomal segment duplications mainly contributed to the expansion of the CsARF, CsIAA, CsGH3, and CsLBD gene families. Quantitative real-time RT-PCR analysis demonstrated that many ARFs, AUX/IAAs, GH3s, SAURs, and LBD genes were expressed in diverse patterns within different organs/tissues and during different development stages. They were also implicated in IAA, methyl jasmonic acid, or salicylic acid response, which is consistent with the finding that a great number of diverse cis-elements are present in their promoter regions involving a variety of signaling transduction pathways. Conclusion Genome-wide comparative analysis of auxin response-related family genes and their expression analysis provide new evidence for the potential role of auxin in development and hormone response of plants. Our data imply that the auxin response genes may be

  18. Theoretical & Experimental Studies of Elementary Particles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McFarland, Kevin

    2012-10-04

    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad programmore » of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities for graduate

  19. The Legacy of the Georgetown College Observatory (D.C.)

    NASA Astrophysics Data System (ADS)

    Caron, Laura; Maglieri, Grace; Seitzer, Patrick

    2018-01-01

    Founded in 1841 as part of a nascent worldwide network of Jesuit-run astronomical observatories, the Georgetown College Observatory of Georgetown University in Washington, D.C. has been home to more than 125 years of astronomical research, from Father Curley’s calculations of the latitude and longitude of D.C. to Father McNally’s award-winning solar eclipse photography. But the impact of the Georgetown astronomy program was not limited to the observatory itself: it reached much further, into the local community and schools, and into the lives of everyone involved. This was never more apparent than under the directorship of Father Francis J Heyden, S.J., who arrived at Georgetown after World War II and stayed for almost three decades. He started a graduate program with over 90 graduates, hosting student researchers from local high schools and colleges, teaching graduate and undergraduate astronomy courses, and speaking at schools in the area, all while simultaneously managing Georgetown’s student radio station and hosting astronomical conferences on campus. Father Heyden’s research focused mainly on solar eclipses for geodetic purposes and planetary spectroscopy. But perhaps even more than research, Father Heyden dedicated his time and energy to the astronomy students, the notable of which include Vera Rubin, John P. Hagen of Project Vanguard, and a generation of Jesuit astronomers including Martin McCarthy, George Coyne, and Richard Boyle. Following the closure of the astronomy department in 1972, Father Heyden returned to Manila, where he had begun his astronomical career, to become Chief of the Solar Division at the Manila Observatory. His dedication to his work and to students serves as an inspiration for academic researchers across fields, and for the Georgetown University Astronomical Society, which, even in the absence of a formal astronomy program at Georgetown, continues his work in education and outreach today. In 1987, almost 150 years after its

  20. Detecting Hydrogen Chloride (HCl) in the Polluted Marine Boundary Layer Using Cavity Ring-Down Spectroscopy (CRDS)

    NASA Astrophysics Data System (ADS)

    Furlani, T.; Dawe, K.; VandenBoer, T. C.; Young, C.

    2017-12-01

    Oxidation initiated with chlorine atoms yields more ozone than oxidation initiated with hydroxyl radicals. Reasons for this are not fully understood, but the implications for mechanisms of oxidation chemistry are significant.1,2 Chlorine atoms have not been directly measured to date in the atmosphere and its abundance is usually inferred through steady-state approximations from all known formation and loss processes. A major reservoir for chlorine in the troposphere is by proton abstraction of organic compounds to form HCl.3 HCl can also be formed heterogeneously via acid displacement reactions with ubiquitously-found sodium chloride (NaCl) on solid surfaces with nitric acid (HNO3). The majority of the available chloride in the marine boundary layer comes from the sea salt in and around marine derived sea-spray aerosols. HCl is not a perfect sink and can react with hydroxyl radicals or be photolyzed to form chlorine atoms. The balance between loss and formation processes of chlorine atoms from HCl is highly dependent on many external factors, such as the wet and dry deposition rate of HCl. Measuring HCl in the gas and aerosol phase is important to the understanding of chlorine chemistry in the polluted marine boundary layer. HCl levels in the polluted marine boundary layer are typically between 100pptv-1ppbv,3 requiring the sensitive and selective detection capabilities of cavity ring-down spectroscopy (CRDS).4 We measured HCl using a Picarro CRDS in the polluted marine boundary layer for the first time. Measurements were conducted during April and May of 2017 in St. John's, Newfoundland and Labrador. The performance of the instrument will be discussed, as well as observations of HCl in the context of local conditions. References1Osthoff, H. D. et al. Nat. Geosci 1, 324-328 (2008). 2Young, C. J. et al. Atmos. Chem. Phys. 14, 3427-3440 (2014). 3Crisp, T. a et al. J. Geophys. Res. Atmos. 6897-6915 (2014). 4Hagen, C. L. et al. Atmos. Meas. Tech. 7, 345-357 (2014).

  1. Gibberellin application at pre-bloom in grapevines down-regulates the expressions of VvIAA9 and VvARF7, negative regulators of fruit set initiation, during parthenocarpic fruit development.

    PubMed

    Jung, Chan Jin; Hur, Youn Young; Yu, Hee-Ju; Noh, Jung-Ho; Park, Kyo-Sun; Lee, Hee Jae

    2014-01-01

    Fruit set is initiated only after fertilization and is tightly regulated primarily by gibberellins (GAs) and auxins. The application of either of these hormones induces parthenocarpy, fruit set without fertilization, but the molecular mechanism underlying this induction is poorly understood. In the present study, we have shown that the parthenocarpic fruits induced by GA application at pre-bloom result from the interaction of GA with auxin signaling. The transcriptional levels of the putative negative regulators of fruit set initiation, including Vitis auxin/indole-3-acetic acid transcription factor 9 (VvIAA9), Vitis auxin response factor 7 (VvARF7), and VvARF8 were monitored during inflorescence development in seeded diploid 'Tamnara' grapevines with or without GA application. Without GA application, VvIAA9, VvARF7, and VvARF8 were expressed at a relatively high level before full bloom, but decreased thereafter following pollination. After GA application at 14 days before full bloom (DBF); however, the expression levels of VvIAA9 and VvARF7 declined at 5 DBF prior to pollination. The effects of GA application on auxin levels or auxin signaling were also analyzed by monitoring the expression patterns of auxin biosynthesis genes and auxin-responsive genes with or without GA application. Transcription levels of the auxin biosynthesis genes Vitis anthranilate synthase β subunit (VvASB1-like), Vitis YUCCA2 (VvYUC2), and VvYUC6 were not significantly changed by GA application. However, the expressions of Vitis Gretchen Hagen3.2 (VvGH3.2) and VvGH3.3, auxin-responsive genes, were up-regulated from 2 DBF to full bloom with GA application. Furthermore, the Vitis GA signaling gene, VvDELLA was up-regulated by GA application during 12 DBF to 7 DBF, prior to down-regulation of VvIAA9 and VvARF7. These results suggest that VvIAA9 and VvARF7 are negative regulators of fruit set initiation in grapevines, and GA signaling is integrated with auxin signaling via VvDELLA during

  2. A 70-year record of outlet glacier retreat in northern Greenland

    NASA Astrophysics Data System (ADS)

    Hill, Emily; Carr, Rachel; Stokes, Chris; Gudmundsson, Hilmar

    2017-04-01

    Over the past two decades, the Greenland Ice Sheet (GrIS) has undergone accelerated mass loss increasing its contribution to sea level rise. This is partly attributed to increased mass loss from dynamic marine-terminating outlet glaciers. Despite marine-terminating outlet glaciers in northern Greenland draining 40% of the ice sheet by area, they are comparatively less well-studied than other regions of the ice sheet (e.g. central west or south-east). This region could be susceptible to marine-ice sheet instability due to large proportions of the bedrock rested below sea level and is also unique in the presence of large floating ice tongues. Here, we use a range of satellite imagery sources, accompanied by historical maps, to examine multi-decadal front position changes at 21 outlet glaciers in northern Greenland between 1948 and 2016. We accompany these terminus changes, with annual records of ice velocity, climate-ocean forcing data, and glacier-specific factors (e.g. fjord-width and basal topography) to understand the dominant forcing on glacier dynamics in the region. Over the last 70 years, there has been a clear pattern of glacier retreat in northern Greenland. This is particularly notable during the last two decades, where 62% of our study glaciers showed accelerated retreat. This was most notable at Humboldt, Tracy, Hagen Brae, C. H. Ostenfeld and Petermann Glaciers, and in the case of the latter three glaciers, this involved substantial retreat of their floating ice tongues (> 10 km). Alongside retreat, several study glaciers underwent simultaneous velocity increases. However, the collapse of floating ice tongues did not always result in increased velocity. Similar to other regions of the ice sheet, recent glacier retreat in the northern regions of the Greenland Ice Sheet could be linked to climatic-oceanic forcing, but at this stage this remains largely unknown. This response to external forcing is further complicated by the presence of glacier

  3. Updating the New Zealand Glacier Inventory

    NASA Astrophysics Data System (ADS)

    Baumann, S. C.; Anderson, B.; Mackintosh, A.; Lorrey, A.; Chinn, T.; Collier, C.; Rack, W.; Purdie, H.

    2017-12-01

    The last complete glacier inventory of New Zealand dates from the year 1978 (North Island 1988) and was manually constructed from oblique aerial photographs and geodetic maps (Chinn 2001). The inventory has been partly updated by Gjermundsen et al. (2011) for the year 2002 (40% of total area) and by Sirguey & More (2010) for the year 2009 (32% of total area), both using ASTER satellite imagery. We used Landsat 8 OLI/TIRS satellite data from February/March 2016 to map the total glaciated area. Clean and debris-covered ice were mapped semi-automatically. The band ratio approach was used for clean ice (ratio: red/SWIR). We mapped debris-covered ice using a supervised classification (maximum likelihood). Manual post processing was necessary due to misclassifications (e.g. lakes, clouds) or mapping in shadowed areas. It was also necessary to manually combine the clean and debris-covered parts into single glaciers. Additional input data for the post processing were Sentinel 2 images from the same time period, orthophotos from Land Information New Zealand (resolution: 0.75 m, date: Nov 2014), and the 1978/88 outlines from the GLIMS database (http://www.glims.org/). As the Sentinel 2 data were more heavily cloud covered compared to the Landsat 8 images, they were only used for post processing and not for the classification itself. Initial results show that New Zealand glaciers covered an area of about 1050 km² in 2016, a reduction of 16% since 1978. Approximately 17% of glacier area was covered in surface debris. The glaciers in the central Southern Alps around Mt Cook reduced in area by 24%. Glaciers in the North Island of New Zealand reduced by 71% since 1988, and only 2 km² of ice cover remained in 2016. Chinn, TJH (2001). "Distribution of the glacial water resources of New Zealand." Journal of Hydrology (NZ) 40(2): 139-187 Gjermundsen, EF, Mathieu, R, Kääb, A, Chinn, TJH, Fitzharris, B & Hagen, JO (2011). "Assessment of multispectral glacier mapping methods and

  4. [Aspects of vascular physiology in clinical and vascular surgical practice: basic principles of vascular mechanics].

    PubMed

    Nocke, H; Meyer, F; Lessmann, V

    2014-10-01

    To be able to evaluate properly a vascular problem, basic concepts of vascular physiology need to be considered, as they have been taught in physiology for a long time. This article deals with selected definitions and laws of passive vascular mechanics, subdivided into parameters of vascular filling and parameters of vascular flow. PARAMETERS OF VASCULAR FILLING: During vascular filling the transmural pressure distends the vascular wall until it is balanced by the wall tension. The extent of this distension up to the point of balance depends on the elasticity of the wall. Transmural pressure, wall tension and elasticity are defined, and their respective importance is described by clinical examples, e.g. aneurysm and varix. PARAMETERS OF VASCULAR FLOW: The vascular flow can be divided into stationary and pulsating components. Both components are relevant for the bloodstream. Since the blood flow is directed in the circuit, it can be understood in first approximation as stationary ("direct current").The direct current model uses only the average values of the pulsating variables. The great advantage of the direct current model is that it can be described with simple laws, which are not valid without reservation, but often allow a first theoretical approach to a vascular problem: Ohm's law, driving pressure, flow resistance, Hagen-Poiseuille law, wall shear stress, law of continuity, Bernoulli's equation and Reynold's number are described and associated with clinical examples.The heart is a pressure-suction pump and produces a pulsating flow, the pulse. The pulse runs with pulse wave velocity, which is much larger than the blood flow velocity, through the arterial vascular system. During propagation, the pulse has to overcome the wave resistance (impedance). Wherever the wave resistance changes, e.g., at vascular bifurcations and in the periphery, it comes to reflections. The incident (forward) and reflected (backward) waves are superimposed to yield the resulting

  5. Coronary Heart Disease Incidence in Sleep Disordered Breathing: The Wisconsin Sleep Cohort Study

    PubMed Central

    Hla, Khin Mae; Young, Terry; Hagen, Erika W.; Stein, James H.; Finn, Laurel A.; Nieto, F. Javier; Peppard, Paul E.

    2015-01-01

    Study Objectives: The aim of the study was to determine the association of objectively measured sleep disordered breathing (SDB) with incident coronary heart disease (CHD) or heart failure (HF) in a nonclinical population. Design: Longitudinal analysis of a community-dwelling cohort followed up to 24 y. Setting: Sleep laboratory at the Clinical Research Unit of the University of Wisconsin Hospital and Clinics. Participants: There were 1,131 adults who completed one or more overnight polysomnography studies, were free of CHD or HF at baseline, were not treated by continuous positive airway pressure (CPAP), and followed over 24 y. Interventions: None. Measurements and Results: In-laboratory overnight polysomnography was used to assess SDB, defined by the apnea-hypopnea index (AHI) using apnea and hypopnea events per hour of sleep. Incident CHD or HF was defined by new reports of myocardial infarction, coronary revascularization procedures, congestive heart failure, and cardiovascular deaths. We used baseline AHI as the predictor variable in survival analysis models predicting CHD or HF incidence adjusted for traditional confounders. The incidence of CHD or HF was 10.9/1,000 person-years. The mean time to event was 11.2 ± 5.8 y. After adjusting for age, sex, body mass index, and smoking, estimated hazard ratios (95% confidence interval) of incident CHD or HF were 1.5 (0.9–2.6) for AHI > 0–5, 1.9 (1.05–3.5) for AHI 5 ≤ 15, 1.8 (0.85–4.0) for AHI 15 ≤ 30, and 2.6 (1.1–6.1) for AHI > 30 compared to AHI = 0 (P trend = 0.02). Conclusions: Participants with untreated severe sleep disordered breathing (AHI > 30) were 2.6 times more likely to have an incident coronary heart disease or heart failure compared to those without sleep disordered breathing. Our findings support the postulated adverse effects of sleep disordered breathing on coronary heart disease and heart failure. Citation: Hla KM, Young T, Hagen EW, Stein JH, Finn LA, Nieto FJ, Peppard PE. Coronary

  6. Scalable analysis of nonlinear systems using convex optimization

    NASA Astrophysics Data System (ADS)

    Papachristodoulou, Antonis

    the Navier-Stokes equations for Hagen-Poiseuille flow are globally stable, even though the background noise is amplified as R3 where R is the Reynolds number, giving a 'robust yet fragile' interpretation. We also propose a sum of squares methodology for the analysis of systems described by parabolic PDEs. We conclude this work with an account for future research.

  7. Public Attitudes Toward Guided Internet-Based Therapies: Web-Based Survey Study.

    PubMed

    Apolinário-Hagen, Jennifer; Harrer, Mathias; Kählke, Fanny; Fritsche, Lara; Salewski, Christel; Ebert, David Daniel

    2018-05-15

    interventions, but not limited to them. Conversely, our results also indicate that efforts should focus on increasing public knowledge about internet interventions, including information about their effectiveness, to promote acceptance and uptake. ©Jennifer Apolinário-Hagen, Mathias Harrer, Fanny Kählke, Lara Fritsche, Christel Salewski, David Daniel Ebert. Originally published in JMIR Mental Health (http://mental.jmir.org), 15.05.2018.

  8. Gibberellin Application at Pre-Bloom in Grapevines Down-Regulates the Expressions of VvIAA9 and VvARF7, Negative Regulators of Fruit Set Initiation, during Parthenocarpic Fruit Development

    PubMed Central

    Jung, Chan Jin; Hur, Youn Young; Yu, Hee-Ju; Noh, Jung-Ho; Park, Kyo-Sun; Lee, Hee Jae

    2014-01-01

    Fruit set is initiated only after fertilization and is tightly regulated primarily by gibberellins (GAs) and auxins. The application of either of these hormones induces parthenocarpy, fruit set without fertilization, but the molecular mechanism underlying this induction is poorly understood. In the present study, we have shown that the parthenocarpic fruits induced by GA application at pre-bloom result from the interaction of GA with auxin signaling. The transcriptional levels of the putative negative regulators of fruit set initiation, including Vitis auxin/indole-3-acetic acid transcription factor 9 (VvIAA9), Vitis auxin response factor 7 (VvARF7), and VvARF8 were monitored during inflorescence development in seeded diploid ‘Tamnara’ grapevines with or without GA application. Without GA application, VvIAA9, VvARF7, and VvARF8 were expressed at a relatively high level before full bloom, but decreased thereafter following pollination. After GA application at 14 days before full bloom (DBF); however, the expression levels of VvIAA9 and VvARF7 declined at 5 DBF prior to pollination. The effects of GA application on auxin levels or auxin signaling were also analyzed by monitoring the expression patterns of auxin biosynthesis genes and auxin-responsive genes with or without GA application. Transcription levels of the auxin biosynthesis genes Vitis anthranilate synthase β subunit (VvASB1-like), Vitis YUCCA2 (VvYUC2), and VvYUC6 were not significantly changed by GA application. However, the expressions of Vitis Gretchen Hagen3.2 (VvGH3.2) and VvGH3.3, auxin-responsive genes, were up-regulated from 2 DBF to full bloom with GA application. Furthermore, the Vitis GA signaling gene, VvDELLA was up-regulated by GA application during 12 DBF to 7 DBF, prior to down-regulation of VvIAA9 and VvARF7. These results suggest that VvIAA9 and VvARF7 are negative regulators of fruit set initiation in grapevines, and GA signaling is integrated with auxin signaling via VvDELLA during

  9. A global, high-resolution data set of ice sheet topography, cavity geometry, and ocean bathymetry

    NASA Astrophysics Data System (ADS)

    Schaffer, Janin; Timmermann, Ralph; Arndt, Jan Erik; Savstrup Kristensen, Steen; Mayer, Christoph; Morlighem, Mathieu; Steinhage, Daniel

    2016-10-01

    The ocean plays an important role in modulating the mass balance of the polar ice sheets by interacting with the ice shelves in Antarctica and with the marine-terminating outlet glaciers in Greenland. Given that the flux of warm water onto the continental shelf and into the sub-ice cavities is steered by complex bathymetry, a detailed topography data set is an essential ingredient for models that address ice-ocean interaction. We followed the spirit of the global RTopo-1 data set and compiled consistent maps of global ocean bathymetry, upper and lower ice surface topographies, and global surface height on a spherical grid with now 30 arcsec grid spacing. For this new data set, called RTopo-2, we used the General Bathymetric Chart of the Oceans (GEBCO_2014) as the backbone and added the International Bathymetric Chart of the Arctic Ocean version 3 (IBCAOv3) and the International Bathymetric Chart of the Southern Ocean (IBCSO) version 1. While RTopo-1 primarily aimed at a good and consistent representation of the Antarctic ice sheet, ice shelves, and sub-ice cavities, RTopo-2 now also contains ice topographies of the Greenland ice sheet and outlet glaciers. In particular, we aimed at a good representation of the fjord and shelf bathymetry surrounding the Greenland continent. We modified data from earlier gridded products in the areas of Petermann Glacier, Hagen Bræ, and Sermilik Fjord, assuming that sub-ice and fjord bathymetries roughly follow plausible Last Glacial Maximum ice flow patterns. For the continental shelf off Northeast Greenland and the floating ice tongue of Nioghalvfjerdsfjorden Glacier at about 79° N, we incorporated a high-resolution digital bathymetry model considering original multibeam survey data for the region. Radar data for surface topographies of the floating ice tongues of Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm have been obtained from the data centres of Technical University of Denmark (DTU), Operation Icebridge (NASA

  10. A model of hydraulic interactions in liver parenchyma as forces behind the intrahepatic bile flow.

    PubMed

    Kurbel, S; Kurbel, B; Dmitrovic, B; Wagner, J

    2001-05-01

    The small diameters of bile canaliculi and interlobular bile ducts make it hard to attribute the bile flow solely to the process of secretion. In the model liver within its capsule is considered a limited space in which volume expansions of one part are possible only through the shrinking of other parts. The liver capsule allows only very slow volume changes. The rate of blood flow through the sinusoides is governed by the Poisseuill-Hagen law. The model is based on a concept of circulatory liver units. A unit would contain a group of acini sharing the same conditions of arterial flow. We can imagine them as an acinar group behind the last pressure reducer on one arterial branch. Acini from neighboring units compose liver lobules and drain through the same central venule. One lobule can contain acini from several neighboring circulatory units. The perfusion cycle in one unit begins with a transient tide in the arterial flow, governed by local mediators. Corresponding acini expand, grabbing the space by compressing their neighbors in the same lobules. Vascular resistance is reduced in dilated and increased in compressed acini. Portal blood flows through the dilated acini, bypassing the compressed neighbors. The cycle ends when the portal tide slowly diminishes and acinar volume is back on the interphase value until the new perfusion cycle is started in another circulatory unit. Each cycle probably takes minutes to complete. Increased pressures both in dilated and in compressed acini force the bile to move from acinar canalicules. Both up and down changes in acinar volume might force the acinar biliary flow. In cases of arterial vasoconstriction, increased activity of vasoactive substances would keep most of the circulatory units in the interphase and increased liver resistance can be expected. Liver fibrosis makes all acini to be of fixed volume and result in increased resistance. Because of that, low pressure portal flow would be more compromised, as reported. In

  11. William Herschel's fifty-two fields of extensive diffused nebulosity - a revision

    NASA Astrophysics Data System (ADS)

    Latusseck, Arndt

    2008-11-01

    Since its publication in 1811, William Herschel's list of fifty-two fields of extensive nebulosity has been largely disregarded, or even discredited, by the astronomical community. Neither he nor his successors decided to include the observations of large structureless fields of background nebulosity in their major catalogues. lt was only during a short period in the early twentieth century that astronomers like I. Roberts, E.E. Barnard, and M. Wolf started more serious investigations into the nature and reality of Herschel's nebulosities, but without deriving conclusive results. Those few who tried to understand Herschel's elusive observations were often puzzled by his ambiguous descriptions and frequently tended to reject the nebulosities as being optical illusions, because only a small number of them could be proven by celestial photography. The only unconditional supporter of the reality of the nebulosities was Johann Georg Hagen, who in the 1920s used them as evidence for his hypothesis that nebulous matter covered almost the entire celestial sphere. He claimed to have succeeded in visually observing nebulous matter in every single one of Herschel's fields, which raised sharp opposition from his numerous critics. The questionable quality of Herschel's original descriptions, the weak supporting arguments, and the lack of photographic evidence, finally led historians to conclude that Herschel's fifty-two fields of extensive nebulosity were illusions. But it would seem astonishing that this gifted observer could have been fooled to such an extent. As a first approach to investigate this apparent anomaly, a complete analysis of Herschel's observing books was carried out, and the raw observations of the various catalogued nebulous fields were extracted. Some important stylistic uncertainties in the descriptions of the visual appearance of the nebulosities were cleared up, leading to a better understanding of what Herschel actually saw. Possible sources of error

  12. Enhancing the performance of a tensioned metastable fluid detector based active interrogation system for the detection of SNM in <1 m3 containers using a D-D neutron interrogation source in moderated/reflected geometries

    NASA Astrophysics Data System (ADS)

    Grimes, T. F.; Hagen, A. R.; Archambault, B. C.; Taleyarkhan, R. P.

    2018-03-01

    This paper describes the development of a SNM detection system for interrogating 1m3 cargos via the combination of a D-D neutron interrogation source (with and without reflectors) and tensioned metastable fluid detectors (TMFDs). TMFDs have been previously shown (Taleyarkhan et al., 2008; Grimes et al., 2015; Grimes and Taleyarkhan, 2016; Archambault et al., 2017; Hagen et al., 2016) to be capable of using Threshold Energy Neutron Analysis (TENA) techniques to reject the ∼2.45 MeV D-D interrogating neutrons while still remaining sensitive to >2.45 MeV neutrons resulting from fission in the target (HEU) material. In order to enhance the performance, a paraffin reflector was included around the accelerator head. This reflector was used to direct neutrons into the package to increase the fission signal, lower the energy of the interrogating neutrons to increase the fission cross-section with HEU, and, also to direct interrogating neutrons away from the detectors in order to enhance the required discrimination between interrogating and fission neutrons. Experiments performed with a 239 Pu-Be neutron source and MnO2 indicated that impressive performance gains could be made by placing a parabolic paraffin moderator between the interrogation source and an air-filled cargo container with HEU placed at the center. However, experiments with other cargo fillers (as specified in the well-known ANSI N42.41-2007 report), and with HEU placed in locations other than the center of the package indicated that other reflector geometries might be superior due to over-"focusing" and the increased solid angle effects due to the accommodation of the moderator geometry. The best performance for the worst case of source location and box fill was obtained by placing the reflector only behind the D-D neutron source rather than in front of it. Finally, it was shown that there could be significant gains in the ability to detect concealed SNM by operating the system in multiple geometric

  13. Mineral-microbial interaction in long term experiments with sandstones and reservoir fluids exposed to CO2

    NASA Astrophysics Data System (ADS)

    Kasina, Monika; Morozova, Daria; Pellizzari, Linda; Würdemann, Hilke

    2013-04-01

    %), whereas after the second sampling it decreased (to 31 relative %) in comparison to the reservoir fluid sample. This may suggest dissolution of silicate minerals at first, and secondary precipitation at second stage of experiment. In addition, immobilization of heavy metals dispersed within silicate minerals was also detected. An increase of Ca (3.2 up to 13% relative), SO4 (up to 14 relative %) and Fetot (47 and 24% relative) were also detected after first and second sampling respectively and may suggest dissolution of cements and iron rich minerals. The concentration of organic acids increased relatively by 12.5 % and 25% after first and second sampling respectively might be an indication for metabolic activity of microorganism or an effect of mobilisation due to CO2 exposure. The presence of newly formed mineral phases was detected using SEM-EDS. Quartz, albite and illite precipitation is a common process in all studied samples. However only illite is considered to be of bacterial origin, nevertheless its crystallization can also occur as a consequence of inorganic diagenetic processes. Further analyses of the microbial community composition, quantity and activity will bring a more insight into the CO2 exposure processes. Daria Morozova, Dagmar Kock, Martin Krüger, and Hilke Würdemann. Biogeochemical and microbial characterization of reservoir fluids from a gas field (Altmark). Geotechnologien 2011

  14. Ethics, transplantation, and the changing role of anatomists.

    PubMed

    Satyapal, K S

    2005-03-01

    Anatomists are regarded as custodians of cadaveric material donated to science. Almost every facet of medical science has experienced explosive advances. This has impacted directly on anatomists and their role. Increasingly, anatomists are raising concerns with regard to the treatment of human tissue (Jones,2002, Clin. Anat. 15:436-440). The Korperwelten (Bodyworlds) of Gunther von Hagens et al. (1987, Anat. Embryol. 175:411-421) has evoked considerable debate about the treatment of human cadavers. Thus far clinical anatomists have had little role to play in policy formulation, legislation, and ethical imperatives as applied to cadaveric donation for organ transplantation. Anatomists play an even more negligible role in the raging ethical controversy around live related/unrelated organ transplantation. Due to the critical international shortage of cadaveric donors, boundaries are being pushed to meet the needs of potential recipients (Ohler,2001, Prog. Transplant. 11:160-161). Constant reappraisal of these ethical and moral issues is therefore appropriate. Issues that relate to cultural and economic imperialism and pronouncements of international transplant societies may also require re-evaluation. The legislature governing the donation of human tissue in various countries is usually governed by a Human Tissue Act or its equivalent. In general, such acts are congruent with the Human Tissue Act (South Africa: Government Gazette 9, November 2001; No. 22824) that states "It is an offense to charge a fee in relation to the donation of human organs." In many countries, however, various lay press report that "the sale of body parts is now coming of age." Terms such as "rewarded gifting" and "donors" being transformed into "vendors" are opening a Pandora's Box (Nelson et al.,1993, "Financial incentives for organ donation: a report on the UNOS ethics committee payment subcommittee"). Cameron and Hoffenberg (1999, Kidney Int. 55:724-732) feel strongly that arguments in

  15. Transient integral boundary layer method to calculate the translesional pressure drop and the fractional flow reserve in myocardial bridges.

    PubMed

    Bernhard, Stefan; Möhlenkamp, Stefan; Tilgner, Andreas

    2006-06-21

    diastole. We have further calculated the wall shear stress (WSS) distributions in addition to the location and length of the flow reversal zones in dependence on the severity of the disease. The described boundary layer method can be used to simulate frictional forces and wall shear stresses in the entrance region of vessels. Earlier models are supplemented by the viscous effects in a quasi three-dimensional vessel geometry with a prescribed wall motion. The results indicate that the translesional pressure drop and the mean FFR compares favourably to clinical findings in the literature. We have further shown that the mean FFR under the assumption of Hagen-Poiseuille flow is overestimated in developing flow conditions.

  16. Physiology of vitreous surgery.

    PubMed

    Stefánsson, Einar

    2009-02-01

    Vitreous surgery has various physiological and clinical consequences, both beneficial and harmful. Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The laws of Fick, Stokes-Einstein and Hagen-Poiseuille state that molecular transport by diffusion or convection is inversely related to the viscosity of the medium. When the vitreous gel is replaced with less viscous saline, the transport of all molecules, including oxygen and cytokines, is facilitated. Oxygen transport to ischemic retinal areas is improved, as is clearance of VEGF and other cytokines from these areas, thus reducing edema and neovascularization. At the same time, oxygen is transported faster down a concentration gradient from the anterior to the posterior segment, while VEGF moves in the opposite direction, making the anterior segment less oxygenated and with more VEGF, stimulating iris neovascularization. Silicone oil is the exception that proves the rule: it is more viscous than vitreous humour, re-establishes the transport barrier to oxygen and VEGF, and reduces the risk for iris neovascularization in the vitrectomized-lentectomized eye. Modern vitreous surgery involves a variety of treatment options in addition to vitrectomy itself, such as photocoagulation, anti-VEGF drugs, intravitreal steroids and release of vitreoretinal traction. A full understanding of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and improves retinal hemodynamics. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and the permeability effect of VEGF reduced with corticosteroids

  17. Metabolic physiology in age related macular degeneration.

    PubMed

    Stefánsson, Einar; Geirsdóttir, Asbjörg; Sigurdsson, Haraldur

    2011-01-01

    the laws of Fick's, Stokes-Einstein and Hagen-Poiseuille. If the vitreous is detached from the surface of the retina, the low viscosity fluid transports oxygen and nutrients towards an ischemic area of the retina, and cytokines away from the retina, at a faster rate than through attached vitreous gel. Vitreoretinal adhesion can exacerbate retinal hypoxia and accumulation of cytokines, such as VEGF. Vitreoretinal traction can also cause hypoxia by retinal elevation. Conceivably, the basic features of AMD, drusen, choroidal ischemia, and vitreoretinal adhesion are independently determined by genetics and environment and may combine in variable proportions. If the resulting hypoxia and consequent VEGF accumulation crosses a threshold, this will trigger effusion and neovascularization. 2010 Elsevier Ltd. All rights reserved.

  18. Transient integral boundary layer method to calculate the translesional pressure drop and the fractional flow reserve in myocardial bridges

    PubMed Central

    Bernhard, Stefan; Möhlenkamp, Stefan; Tilgner, Andreas

    2006-01-01

    during re-opening of the vessel in diastole. We have further calculated the wall shear stress (WSS) distributions in addition to the location and length of the flow reversal zones in dependence on the severity of the disease. Conclusion The described boundary layer method can be used to simulate frictional forces and wall shear stresses in the entrance region of vessels. Earlier models are supplemented by the viscous effects in a quasi three-dimensional vessel geometry with a prescribed wall motion. The results indicate that the translesional pressure drop and the mean FFR compares favourably to clinical findings in the literature. We have further shown that the mean FFR under the assumption of Hagen-Poiseuille flow is overestimated in developing flow conditions. PMID:16790065

  19. Modeling the weather impact on aviation in a global air traffic model

    NASA Astrophysics Data System (ADS)

    Himmelsbach, S.; Hauf, T.; Rokitansky, C. H.

    2009-09-01

    Weather has a strong impact on aviation safety and efficiency. For a better understanding of that impact, especially of thunderstorms and similar other severe hazards, we pursued a modeling approach. We used the detailed simulation software (NAVSIM) of worldwide air traffic, developed by Rokitansky [Eurocontrol, 2005] and implemented a specific weather module. NAVSIM models each aircraft with its specific performance characteristics separately along preplanned and prescribed routes. The specific weather module in its current version simulates a thunderstorm as an impenetrable 3D object, which forces an aircraft to circumvent the latter. We refer to that object in general terms as a weather object. The Cb-weather object, as a specific weather object, is a heuristic model of a real thunderstorm, with its characteristics based on actually observed satellite and precipitation radar data. It is comprised of an upper volume, mostly the anvil, and a bottom volume, the up- and downdrafts and the lower outflow area [Tafferner and Forster, 2009; Kober and Tafferner 2009; Zinner et al, 2008]. The Cb-weather object is already implemented in NAVSIM, other weather objects like icing and turbulence will follow. This combination of NAVSIM with a weather object allows a detailed investigation of situations where conflicts exist between planned flight routes and adverse weather. The first objective is to simulate the observed circum-navigation in NAVSIM. Real occurring routes will be compared with simulated ones. Once this has successfully completed, NAVSIM offers a platform to assess existing rules and develop more efficient strategies to cope with adverse weather. An overview will be given over the implementation status of weather objects within NAVSIM and first results will be presented. Cb-object data provision by A. Tafferner, C. Forster, T. Zinner, K. Kober, M. Hagen (DLR Oberpfaffenhofen) is greatly acknowledged. References: Eurocontrol, VDL Mode 2 Capacity Analysis through

  20. Current Views and Perspectives on E-Mental Health: An Exploratory Survey Study for Understanding Public Attitudes Toward Internet-Based Psychotherapy in Germany.

    PubMed

    Apolinário-Hagen, Jennifer; Vehreschild, Viktor; Alkoudmani, Ramez M

    2017-02-23

    , which we labeled "usefulness or helpfulness," "relative advantage or comparability," and "accessibility or access to health care." Analyses revealed negative views about Internet-based therapies on most domains, such as perceived helpfulness. The study findings further indicated ambivalent attitudes: Although most respondents agreed to statements on expected improvements in health care (eg, expanded access), we observed low intentions to future use of Internet-delivered therapies in case of mental health problems. This pilot study showed deficient "e-awareness" and rather negative or ambivalent attitudes toward Internet-delivered therapies in the German-speaking general population. However, research targeting determinants of the large-scale adoption of Internet-based psychotherapy is still in its infancy. Thus, further research is required to explore the "black box" of public attitudes toward Internet-delivered therapies with representative samples, validated measures, and longitudinal survey designs. ©Jennifer Apolinário-Hagen, Viktor Vehreschild, Ramez M Alkoudmani. Originally published in JMIR Mental Health (http://mental.jmir.org), 23.02.2017.

  1. Ex vivo culture of human fetal gonads: manipulation of meiosis signalling by retinoic acid treatment disrupts testis development.

    PubMed

    Jørgensen, A; Nielsen, J E; Perlman, S; Lundvall, L; Mitchell, R T; Juul, A; Rajpert-De Meyts, E

    2015-10-01

    '-deoxyuridine (BrdU) incorporation assay. A novel ex vivo 'hanging-drop' culture model for human fetal gonads was successfully established. Continued proliferation of cells without signs of increased apoptosis was observed after 2 weeks of culture. In cultured fetal ovaries treated with RA, an increased number of meiotic germ cells (P < 0.05) and DMRT1-positive oogonia initiating meiosis (P < 0.05) was observed, which is in agreement with a previous study. In fetal testes, RA-treatment resulted in a decreased number of gonocytes (P < 0.05), a reduced percentage of proliferating gonocytes (P < 0.05), altered expression pattern of the somatic cell markers AMH and COUP-TFII, as well as disrupted seminiferous cord structure and testis morphology. The number of samples included in this study was relatively small due to the limited availability of human fetal tissue. The hanging-drop culture, similarly to other organ culture approaches, allows studies of germ cell-somatic niche interactions and determination of effects after manipulating specific signalling pathways. Our novel finding of disrupted fetal testis development after treatment with RA indicates that abnormal meiosis regulation can potentially cause gonadal dysgenesis. Further studies will elucidate the exact mechanisms and timing of observed effects. This work was supported in part by an ESPE Research Fellowship, sponsored by Novo Nordisk A/S to A.Jø. Additional funding for this project was obtained from The Research Council of the Capital Region of Denmark (E.R.-D.M.), The Research Fund at Rigshospitalet (A.Ju. and J.E.N.), Familien Erichssens Fund (A.Jø.), Dagmar Marshalls Fund (A.Jø.) and Aase & Ejnar Danielsens Fund (A.Jø.). The authors have no conflicts of interest. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Smart Application of Direct Gas Injection using a new conceptual model on Coherent and Incoherent Flow: From Bench Scale to Field Scale.

    NASA Astrophysics Data System (ADS)

    Geistlinger, H.; Samani, S.; Pohlert, M.; Martienssen, M.; Engelmann, F.; Hüttmann, S.

    2008-12-01

    Within the framework of the OXYWALL field experiment we developed the direct gas injection (DGI) of oxygen as a remediation technology, which allows the cost-efficient and large-scale cleaning of groundwater contaminated with organic contaminants. That technology can be used as wide-banded, unselective remediation method for complex contaminant mixtures. Particularly, it could be proofed in field experiments that mineral oil hydrocarbons, aromatic hydrocarbons (BTEX), the rather persistent gasoline component Methyl tertiary-butyl ether (MTBE), and chlorinated aliphatic and aromatic hydrocarbons, like Trichloroethene and Monochlorobenzene, can be aerobically metabolized by autochthon microorganisms. Over the last 8 years the field site was investigated and a dense monitoring network was installed using Geoprobe direct- push technology and standard hydrogeological investigations were conducted, like EC-Logs, Injections-Logs, Gamma-Logs, TDR-probes, oxygen measurements with in-situ optodes, and tracer test with test gases SF6, Ar, and Oxygen. The key parameter for controling and regulating the DGI is the spatial and temporal distribution of the gas phase. High-resolution optical bench scale experiments were conducted in order to investigate local gas flow pattern and integral flow properties caused by point-like gas injection into water-saturated glass beads and natural sands. We observed a grain-size (dk)- and flow-rate (Q) dependent transition from incoherent to coherent flow. Conceptualizing the stationary tortuous gas flow as core-annulus flow and applying Hagen- Poiseuille flow for a straight capillary, we propose a flow-rate- and grain-size dependent stability criterion that could describe our experimental results and was used for classifying the experiments in a dk-Q-diagram (flow chart). Since DGI simulations are mainly based on continuum models, we also test the validity of the continuum approach for two-fluid flow in macroscopic homogeneous media by

  3. Documentation of a Conduit Flow Process (CFP) for MODFLOW-2005

    USGS Publications Warehouse

    Shoemaker, W. Barclay; Kuniansky, Eve L.; Birk, Steffen; Bauer, Sebastian; Swain, Eric D.

    2007-01-01

    modifying horizontal conductances assembled by the Block-Centered Flow (BCF), Layer-Property Flow (LPF), or Hydrogeologic-Unit Flow Packages (HUF) of MODFLOW-2005. For both conduit flow pipes (CFPM1) and preferential flow layers (CFPM2), critical Reynolds numbers are used to determine if flow is laminar or turbulent. Due to conservation of momentum, flow in a laminar state tends to remain laminar and flow in a turbulent state tends to remain turbulent. This delayed transition between laminar and turbulent flow is introduced in the CFP, which provides an additional benefit of facilitating convergence of the computer algorithm during iterations of transient simulations. Specifically, the user can specify a higher critical Reynolds number to determine when laminar flow within a pipe converts to turbulent flow, and a lower critical Reynolds number for determining when a pipe with turbulent flow switches to laminar flow. With CFPM1, the Hagen-Poiseuille equation is used for laminar flow conditions and the Darcy-Weisbach equation is applied to turbulent flow conditions. With CFPM2, turbulent flow is approximated by reducing the laminar hydraulic conductivity by a nonlinear function of the Reynolds number, once the critical head difference is exceeded. This adjustment approximates the reductions in mean velocity under turbulent ground-water flow conditions.

  4. Combining Information on Multiple Detection Techniques to Estimate the Effect of Patent Foramen Ovale on Susceptibility to Decompression Illness

    NASA Technical Reports Server (NTRS)

    Feiveson, Alan H.; Foster, Philip P.

    2001-01-01

    The assembly and the maintenance of the International Space Station is expected to require hundreds of extravehicular excursions (EVA's) in the next 10 years. During an EVA, in order to allow movement and bending of limbs, spacesuit pressures are reduced to about 4.3 psi. as compared with about 14.7 psi. for normal atmospheric pressure at sea level. However, the exposure of astronauts to reduced pressures in spacesuits, is conducive to fonnation and growth of gas bubbles within venous blood or tissues, which could cause decompression illness (DCI), a pathology best known to occur among deep-sea divers when they return to the surface. To reduce the risk of DCI, astronauts adjust to the reduced pressure in stages for a prolonged time known as a "pre-breathe" period prior to their extravehicular activity. Despite the use of pre-breathe protocols, an increased risk of DCI can arise for about 25% of humans who have a small hole, known as a patent foramen ovale (PFO), between two chambers of the heart. The atrial septum's fossa oval is, an embryological remnant of a flap between the septae primum and secundum allows fetal right atrial blood to pass into the left atrium, and usually closes after birth (Hagen, et al,. 1984). If fusion does not occur, a valve-like opening, the foramen ovale persists between the two atria. It has been suggested that astronauts with PFO's might be at greater risk of stroke or other serious neurological DCI because bubbles from a venous site may traverse a PFO, travel to the aorta and then enter the cerebral circulatory system causing a stroke (Figure 1). Astronauts are not now screened for PFO's, however consideration is being given to doing so. Here, we study three main methods abbreviated here as "ITE", "TCD" and "TEE", for detecting PFO's in living subjects. All involve the introduction of bubbles into a vein, immediately after which a sensory probe attempts to detect the bubbles in systemic circulation. Presence of the injected bubbles in

  5. Nonobservable nature of the nuclear shell structure: Meaning, illustrations, and consequences

    NASA Astrophysics Data System (ADS)

    Duguet, T.; Hergert, H.; Holt, J. D.; Somà, V.

    2015-09-01

    Background: The concept of single-nucleon shells constitutes a basic pillar of our understanding of nuclear structure. Effective single-particle energies (ESPEs) introduced by French [Proceedings of the International School of Physics "Enrico Fermi," Course XXXVI, Varenna 1965, edited by C. Bloch (Academic Press, New York, 1966)] and Baranger [Nucl. Phys. A 149, 225 (1970), 10.1016/0375-9474(70)90692-5] represent the most appropriate tool to relate many-body observables to a single-nucleon shell structure. As briefly discussed in Duguet and Hagen [Phys. Rev. C 85, 034330 (2012), 10.1103/PhysRevC.85.034330], the dependence of ESPEs on one-nucleon transfer probability matrices makes them purely theoretical quantities that "run" with the nonobservable resolution scale λ employed in the calculation. Purpose: Given that ESPEs provide a way to interpret the many-body problem in terms of simpler theoretical ingredients, the goal is to specify the terms, i.e., the exact sense and conditions, in which this interpretation can be conducted meaningfully. Methods: While the nuclear shell structure is both scale and scheme dependent, the present study focuses on the former. A detailed discussion is provided to illustrate the scale (in)dependence of observables and nonobservables and the reasons why ESPEs, i.e., the shell structure, belong to the latter category. State-of-the-art multireference in-medium similarity renormalization group and self-consistent Gorkov Green's function many-body calculations are employed to corroborate the formal analysis. This is done by comparing the behavior of several observables and of nonobservable ESPEs (and spectroscopic factors) under (quasi) unitary similarity renormalization group transformations of the Hamiltonian parametrized by the resolution scale λ . Results: The formal proofs are confirmed by the results of ab initio many-body calculations in their current stage of implementation. In practice, the unitarity of the similarity

  6. Influence of Biological Macromolecules and Aquatic Chemistries on the Inhibition of Nitrifying Bacteria by Silver Nanoparticles

    NASA Astrophysics Data System (ADS)

    Radniecki, T. S.; Anderson, J. W.; Schneider, M. C.; Stankus, D. P.; Nason, J. A.; Semprini, L.

    2010-12-01

    -NP solution even in the presence of divalent cations. This stable Ag-NP/NOM dispersion resulted in higher toxicity in the presence of divalent cations than Ag-NP alone. This work also examined the effect of the presence of biological macromolecules, including proteins and lipopolysaccharides, on Ag-NP stability and toxicity. Acknowledgements We would like to thank nanoComposix, Inc. for donating the Ag-NPs. This research was funded through an Oregon Nanoscience and Microtechnologies Institute/United State Air Force Research Labs grant # 235271B, Amend. No. 5. References (1) Wijnhoven, S.; Peijnenburg, W.; Herberts, C.; Hagens, W.; Werner, I.; Oomen, A.; Heugens, E.; Roszek, B.; Bisschops, J.; Gosens, I.; van de Meent, D.; Kekkers, S.; de Jong, W.; van Zijverden, M.; Sips, A.; Geertsma, R., Nano-silver - a review of available data and knowledge gaps in human and environmental risk assessment. Nanotoxicology 2009 1:1-30. (2) Choi, O.; Cleuenger, T. E.; Deng, B. L.; Surampalli, R. Y.; Ross, L.; Hu, Z. Q., Role of sulfide and ligand strength in controlling nanosilver toxicity. Water Research 2009 43(7):1879-1886.

  7. The Richard T. Cox Lecture: Liquid State as an Occasional Result of Competing Interactions

    NASA Astrophysics Data System (ADS)

    Voronel, Alexander

    2006-03-01

    liquids (including mixtures) in the vicinities of the singular points by the universal functions of reduced coordinates [5]. But the very existence of the critical point (and the liquid state itself) is in fact not an universal property of matter [6]. The freezing is depen-dent on a symmetry of packing and on a form of a potential well. It means the lower limit of the liquid state cannot be universal. However, if the freezing is somehow avoided the metastable critical point may be achieved instead [7]. And the universal features of the critical phenomena may be observed there again. Literature: [1] A. Voronel, M. Gitterman, Zh. Exp. Teor. Fiz. 39, 1162 (1960). M.Bagatsky, A.Voronel, V.Gusak., Zh. Exp. Teor. Fiz. 43, 728 (1962). See also a review: A. Voronel ``Thermal measurements and Critical Phenomena in Liquids.'' in PHASE TRANSITIONS AND CRITICAL PHENOMENA, vol. 5B, ed. by C.DOMB & M.S.GREEN, 1976, Academic Press, London, New York, San Francisco. [2] M.J.Buckingham, W.M.Fairbank in 111,60, ``PROGRESS IN LOW TEMPERATURE PHYSICS''(ed. by C.J.Gorter) North-Holland Pub.Co., Amsterdam, 1961. [3] M.E.Fisher,''The Nature of Critical Points'', University of Colorado Press, Boulder, 1965; [4] A.Patashinsky,V.Pokrovsky, Sov.Phys.JETP,23,292,(1966); L.P.Kadanov, Physics, 2,263, (1966) [5] M.E.Fisher, Phys.Rev.,176, 257, (1968); M.A.Anisimov, A.V.Voronel, E.E.Gorodetsky, Zh.Exp.Teor.Fiz.,60,1117, (1971) [6] H.J.Hagen,D.Frenkel,H.Lekkerkerker, Nature, 365, 425, (1993); D.Frenkel, Physica, A 263, 26, (1999). G.Vliegenthardt, H.Lekkerkerker, Physica, A 263, 378, (1999). [7] O.Mishima,H.E.Stanley, Nature, 392, 164, (1998).

  8. FURTHER STUDY OF SOMA, DENDRITE, AND AXON EXCITATION IN SINGLE NEURONS

    PubMed Central

    Eyzaguirre, Carlos; Kuffler, Stephen W.

    1955-01-01

    The present investigation continues a previous study in which the soma-dendrite system of sensory neurons was excited by stretch deformation of the peripheral dendrite portions. Recording was done with intracellular leads which were inserted into the cell soma while the neuron was activated orthodromically or antidromically. The analysis was also extended to axon conduction. Crayfish, Procambarus alleni (Faxon) and Orconectes virilis (Hagen), were used. 1. The size and time course of action potentials recorded from the soma-dendrite complex vary greatly with the level of the cell's membrane potential. The latter can be changed over a wide range by stretch deformation which sets up a "generator potential" in the distal portions of the dendrites. If a cell is at its resting unstretched equilibrium potential, antidromic stimulation through the axon causes an impulse which normally overshoots the resting potential and decays into an afternegativity of 15 to 20 msec. duration. The postspike negativity is not followed by an appreciable hyperpolarization (positive) phase. If the membrane potential is reduced to a new steady level a postspike positivity appears and increases linearly over a depolarization range of 12 to 20 mv. in various cells. At those levels the firing threshold of the cell for orthodromic discharges is generally reached. 2. The safety factor for conduction between axon and cell soma is reduced under three unrelated conditions, (a) During the recovery period (2 to 3 msec.) immediately following an impulse which has conducted fully over the cell soma, a second impulse may be delayed, may invade the soma partially, or may be blocked completely. (b) If progressive depolarization is produced by stretch, it leads to a reduction of impulse height and eventually to complete block of antidromic soma invasion, resembling cathodal block, (c) In some cells, when the normal membrane potential is within several millivolts of the relaxed resting state, an antidromic

  9. EDITORIAL: Towards the next node in downsized devices Towards the next node in downsized devices

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-02-01

    al 2008 Nanotechnology 19 505302 [5] Leu P W et al 2008 Nanotechnology 19 485705 [6] Botman A, Mulders J J L and Hagen C W 2009 Nanotechnology 20 372001 [7] Habicht S, Zhao Q T, Feste S F, Knoll L, Trellenkamp S, Ghyselen B and Mantl S 2010 Nanotechnology 21 105701 [8] Münch S, Reitzenstein S, Borgström M, Thelander C, Samuelson L, Worschech L and Forchel A 2010 Nanotechnology 21 105711

  10. Dedication: phys. stat. sol. (a) 202/15

    NASA Astrophysics Data System (ADS)

    Albrecht, Martin

    2005-12-01

    thorough understanding of materials problems would require the combined use of structural characterisation, advanced spectroscopy and modelling. Therefore he complemented electron microscopic approaches by optical methods e.g. Raman spectroscopy and cathodoluminescence. Modelling of strain states by finite elements and of defect structures by ab-initio calculations became an important topic especially in the last years. It is characteristic for the scientific approach of Horst Strunk that methodological developments were not an end in itself but linked to problems in solid state physics and materials sciences. Among the scientific works of Strunk, a few examples should be highlighted which mark important stages in his scientific career. Pioneering work has been done on the influence of dislocations in homoepitaxial growth of Si and GaAs in collaboration with Elisabeth Bauser in Stuttgart. Strunk correlated growth spirals on the surface to dislocations that caused these step sources. Studying the dislocation structure of heteroepitaxial Ge/GaAs layers, Strunk discovered that a new dislocation multiplication source works which, later known as Hagen-Strunk source, had a strong impact on understanding of relaxation processes by dislocations in heteroepitaxial semiconductor systems. Work on electrical and structural properties of grain boundaries in silicon was performed together with Jürgen Werner. This was the starting point of a long lasting research on photovoltaic materials that accompanies Strunk till today. Fundamental studies on heteroepitaxial growth were performed in the system SiGe grown from solution. In this context, finite elements were established for the first time in the study of nanostructured materials. In the last years correlated studies on structural and optical properties on III-nitride heterostructures were done by cathodoluminescence in the transmission electron microscope. The impact of Horst P. Strunk's work is evident from the fact that his lab

  11. EDITORIAL: Advances in Measurement Technology and Intelligent Instruments for Production Engineering

    NASA Astrophysics Data System (ADS)

    Gao, Wei; Takaya, Yasuhiro; Gao, Yongsheng; Krystek, Michael

    2008-08-01

    the other papers, two are related to length measurement, which forms the basis of dimensional measurement. Schödel et al from Physikalisch Technische Bundesanstalt (PTB) describe the recent state of thermal expansion measurements with PTB's Precision Interferometer, which are based on the observation of the absolute length of samples by using phase stepping interferometry. Meiners-Hagen et al, also from PTB, investigate an improved method for compensation of the refractive index of air in length measurements by optical interferometry where the air pressure and the humidity are measured. Three papers concern surface metrology. Song et al from NIST (National Institutes of Standards and Technology) report topography measurement for determining the decay factors in surface replication of Standard Casing to support ballistics measurements in the US. Takahashi et al from the University of Tokyo present a lateral resolution improvement for a total internal reflection fluorescence microscope that employs the combined use of standing evanescent light and a scattering distribution retrieval algorithm with successive approximation. X Liu et al from Warwick University report on a new investigation into how surface topography and friction affect the touch-feel perception, with the results showing that both the measured roughness and friction coefficient have a strong correlation with rough-smooth and grippy-slippery feelings. Measurement algorithms and calibration are described in the following three papers. Hessling from SP Technical Research Institute of Sweden presents a general unprecedented framework for dynamic evaluation of measurement systems, which separates physical experiments, analysis and signal processing methods into succeeding steps of evaluations. Wübbeler et al from PTB illustrate the Monte Carlo method required for the numerical calculations of the probability density function approach, which has been proposed for evaluation of measurement uncertainty

  12. EDITORIAL: Enhancing nanolithography Enhancing nanolithography

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2012-01-01

    interfering laser beams. The interference gave rise to a periodic line-like pattern in the intensity distribution of the incident field. In addition, the silica spheres cause enhancements to the incident field that result in the formation of patterns of craters, cavities and holes in the PEDOT-PSS. The researchers confirm the viability of their fabrication process with Mie scattering theory calculations. The technique has a number of advantages over previous methods for creating nanoporous structures in PEDOT-PSS, including efficiency, high-resolution and low cost as a clean room is not required. The stage is set for more technological developments as innovations in lithography and combinations with other techniques continue to play a leading role in high-resolution patterning and fabrication at the nanoscale. References [1] Grigorescu A E and Hagen C W 2009 Nanotechnology 20 292001 [2] Lin B J 1975 J. Vac. Sci. Technol. 12 1317-20 [3] Yuan D, Lasagni A, Hendricks J L, Martin D C and Das S 2012 Nanotechnology 23 015304 [4] Kim S H, Lee K-D, Kim J-Y, Kwon M-K and Park S-J 2007 Nanotechnology 18 055306 [5] Yu J, Ippolito S J, Wlodarski W, Strano M and Kalantar-Zadeh K 2010 Nanotechnology 21 265502 [6] Yang Y, Tanemura M, Huang Z, Jiang D, Li Z-Y, Huang Y-P, Kawamura G, Yamaguchi K and Nogami M 2010 Nanotechnology 21 325701 [7] Cade N I, Ritman-Meer T, Kwakwa K A and Richards D 2009 Nanotechnology 20 285201

  13. Tracer-based quantification of individual frac discharge in single-well multiple-frac backflow: sensitivity study

    NASA Astrophysics Data System (ADS)

    Ghergut, Julia; Behrens, Horst; Sauter, Martin

    2014-05-01

    a simplified flow and tracer transport model (using FEOW and assuming Darcian flow within the matrix, Hagen-Poiseuille flow within the waterfrac, and either D or H-P flow within the gel-proppant fracs), whose main findings are: (1) late tracer signals are almost independent on matrix porosity, permeability distribution, frac area (length), thickness and effective aperture, while being highly sensitive to local discharge values; 'late' means a backflow or production volume at least fivefold the injected chaser volume; (2a) early tracer signals (concentration 'peak' intervals) may exhibit slight 'acceleration' and 'damping' with increasing matrix porosity or increasing frac aperture (a 'paradoxical' behaviour which is not really surprising for single-well 'push-then-backflow' tests, actually owing to flow-field dispersion[4]), and (2b) a non-monotonous response to varying frac area, being almost insensitive to frac area as long as the linear-flow regime prevails against the radial-flow regime (effects of the latter only becoming visible at very low frac areas); (2c) the effects of these various factors on early-time tracer signals are not unambiguously discernible from each other, and this ambiguity would persist even if frac-resolved (in-situ) discharge metering were feasible. For each of the three fracs (k=1,2,3), a 'type-curve' set Ck(Q,t) (parametrized by discharge values Q) can be generated. Since every frac received a different tracer, tracer signals measured within the overall backflow will differ from individual-frac type-curves by mere dilution (no 'superposition'). Type-curve dilution by factor Qk/Qtotal can be compared to measured tracer concentrations in the total discharge, ck(ti), (i = 1, ..., no. of tracer samplings). From a formal point of view, the unknown discharge values Qk can be determined as the solution of a linear optimization task subject to the constraint Q1 + Q2 + Q3 = Qtotal (the latter being a measured value). It is recommendable to

  14. Additive Manufacturing, Design, Testing, and Fabrication: A Full Engineering Experience at JSC

    NASA Technical Reports Server (NTRS)

    Zusack, Steven

    2016-01-01

    I worked on several projects this term. While most projects involved additive manufacturing, I was also involved with two design projects, two testing projects, and a fabrication project. The primary mentor for these was Richard Hagen. Secondary mentors were Hai Nguyen, Khadijah Shariff, and fabrication training from James Brown. Overall, my experience at JSC has been successful and what I have learned will continue to help me in my engineering education and profession long after I leave. My 3D printing projects ranged from less than a 1 cubic centimeter to about 1 cubic foot and involved several printers using different printing technologies. It was exciting to become familiar with printing technologies such as industrial grade FDM (Fused Deposition Modeling), the relatively new SLA (Stereolithography), and PolyJet. My primary duty with the FDM printers was to model parts that came in from various sources to print effectively and efficiently. Using methods my mentor taught me and the Stratasys Insight software, I was able to minimize imperfections, hasten build time, improve strength for specific forces (tensile, shear, etc...), and reduce likelihood of a print-failure. Also using FDM, I learned how to repair a part after it was printed. This is done by using a special kind of glue that chemically melts the two faces of plastic parts together to form a fused interface. My first goal with SLA technology was to bring the printer back to operational readiness. In becoming familiar with the Pegasus SLA printer, I researched the leveling, laser settings, and different vats to hold liquid material. With this research, I was successfully able to bring the Pegasus back online and have successfully printed multiple sample parts as well as functional parts. My experience with PolyJet technology has been focused on an understanding of the abilities/limits, costs, and the maintenance for daily use. Still upcoming will be experience with using a composite printer that uses FDM

  15. PREFACE: Particles and Fields: Classical and Quantum

    NASA Astrophysics Data System (ADS)

    Asorey, M.; Clemente-Gallardo, J.; Marmo, G.

    2007-07-01

    , Germany) G. F. Dell Antonio (Universitá di Roma La Sapienza, Italy) A. Galindo (Universidad Complutense de Madrid, Spain) S. L. Glashow (Boston University, USA) A. M. Gleeson (University of Texas, Austin, USA) C. R. Hagen (Rochester University, NY, USA) J. Klauder (University of Florida, Gainesville, USA) A. Kossakowski (University of Torun, Poland) V.I. Manko (Lebedev Physical Institute, Moscow, Russia) G. Marmo (Universitá Federico II di Napoli e INFN Sezione di Napoli, Italy) N. Mukunda (Indian Institute of Science, Bangalore, India) J. V. Narlikar (Inter-University Centre for Astronomy and Astrophysics, Pune, India) J. Nilsson (University of Goteborg, Sweden) S. Okubo (Rochester University, NY, USA) T. Regge (Politecnico di Torino, Italy) W. Schleich (University of Ulm, Germany) M. Scully (Texas A& M University, USA) S. Weinberg (University of Texas, Austin, USA)

    Local Organizing Committee

    M. Asorey (Universidad de Zaragoza, Spain)
    L. J. Boya (Universidad de Zaragoza, Spain). Co-Chair
    J. F. Cariñena (Universidad de Zaragoza, Spain)
    J. Clemente-Gallardo (Universidad de Zaragoza, Spain)
    F. Falceto (Universidad de Zaragoza, Spain)
    G. Marmo (Universitá Federico II di Napoli e INFN Sezione di Napoli, Italy) Co-Chair
    G. Morandi (Universitá di Bologna, Italy)

    Participants

    ACHARYA, Raghunath: Arizona State University, USA
    AGUADO, Miguel M.: Max-Planck-Institut für Quantenoptik, Garching, Germany
    ASOREY, Manuel: Universidad de Zaragoza, Spain

  16. Nanotechnology in paper electronics

    NASA Astrophysics Data System (ADS)

    Demming, Anna; Österbacka, Professor Ronald; Han, Jin-Woo, Dr

    2014-03-01

    devices. If 'writing is thinking on paper' [15], it seems researchers are finding yet more powerful means of putting their ideas on paper. References [1] Barquinha P, Martins R, Pereira L and Fortunato E 2012 Transparent Oxide Electronics: From Materials to Devices (Chichester: Wiley) [2] Zocco A T, You H, Hagen J A and Steckl A J 2014 Pentacene organic thin film transistors on flexible paper and glass substrates Nanotechnology 25 094005 [3] Pereira L, Gaspar D, Guerin D, Delattre A, Fortunato E and Martins R 2014 The influence of fibril composition and dimension on the performance of paper gated oxide transistors Nanotechnology 25 094007 [4] Wu G, Wan C, Zhou J, Zhu L and Wan Q 2014 Low-voltage protonic/electronic hybrid indium-zinc-oxide synaptic transistors on paper substrates Nanotechnology 25 094001 [5] Shin H, Yoon B, Park I S and Kim J-M 2014 An electrothermochromic paper display based on colorimetrically reversible polydiacetylenes Nanotechnology 25 094011 [6] Ihalainen P, Pettersson F, Pesonen M, Viitala T, Määttänen A, Österbacka R and Peltonen J 2014 An impedimetric study of DNA hybridization on paper supported inkjet-printed gold electrodes Nanotechnology 25 094009 [7] Wang Y, Shi Y, Zhao C X, Wong J I, Sun X W and Yang H Y 2014 Printed all-solid flexible microsupercapacitors: towards the general route for high energy storage device Nanotechnology 25 094010 [8] Andersson H A, Manuilskiy A, Haller S, Hummelgård M, Sidén J, Hummelgård C, Olin H and Nilsson H-E 2014 Assembling surface mounted components on ink-jet printed double sided paper circuit board Nanotechnology 25 094002 [9] Gaspar D, Fernandes S N, de Oliveira A G, Fernandes J G, Grey P, Pontes R V, Pereira L, Martins R, Godinho M H and Fortunato E 2014 Nanocrystalline cellulose applied simultaneously as gate dielectric and substrate on flexible field effect transistors Nanotechnology 25 094008 [10] Männl U, van den Berg C, Magunje B, Härting M, Britton D T, Jones S, Mvan Staden M J and Scriba M

  17. Preface: SciDAC 2006

    NASA Astrophysics Data System (ADS)

    Tang, William M., Dr.

    2006-01-01

    scheduling the promotional activities that took place during the conference; to John Bui and John Smith for their superb wireless networking and A/V set-up and support; to Cindy Latham for Web site design, graphic design, and quality control of proceedings submissions; and to Pamelia Nixon-Hartje of Ambassador for budget and quality control of catering. We are grateful for the highly professional dedicated efforts of all of these individuals, who were the cornerstones of the SciDAC 2006 Conference. Thanks also go to Angela Beach of the ORNL Conference Center for her efforts in executing the contracts with the hotel, Carolyn James of Colorado State for on-site registration supervision, Lora Wolfe and Brittany Hagen for administrative support at ORNL, and Dami Rich and Andrew Sproles for graphic design and production. We are also most grateful to the Oak Ridge National Laboratory, especially Jeff Nichols, and to our corporate sponsors, Data Direct Networks, Cray, IBM, SGI, and Institute of Physics Publishing for their support. We especially express our gratitude to the featured speakers, invited oral speakers, invited poster presenters, session chairs, and advanced architecture panelists and chair for their excellent contributions on behalf of SciDAC 2006. We would like to express our deep appreciation to Lali Chatterjee, Graham Douglas, Margaret Smith, and the production team of Institute of Physics Publishing, who worked tirelessly to publish the final conference proceedings in a timely manner. Finally, heartfelt thanks are extended to Michael Strayer, Associate Director for OASCR and SciDAC Director, and to the DOE program managers associated with SciDAC for their continuing enthusiasm and strong support for the annual SciDAC Conferences as a special venue to showcase the exciting scientific discovery achievements enabled by the interdisciplinary collaborations championed by the SciDAC program.

  18. Preface: SciDAC 2005

    NASA Astrophysics Data System (ADS)

    Mezzacappa, Anthony

    2005-01-01

    in procurement and setting up and executing the contracts with the hotel, and to John Bui and John Smith for their superb wireless networking and A/V set up and support. We are grateful for the relentless efforts of all of these individuals, their remarkable talents, and for the joy of working with them during this past year. They were the cornerstones of SciDAC 2005. Thanks also go to Kymba A'Hearn and Patty Boyd for on-site registration, Brittany Hagen for administrative support, Bruce Johnston for netcast support, Tim Jones for help with the proceedings and Web site, Sherry Lamb for housing and registration, Cindy Lathum for Web site design, Carolyn Peters for on-site registration, and Dami Rich for graphic design. And we would like to express our appreciation to the Oak Ridge National Laboratory, especially Jeff Nichols, the Argonne National Laboratory, the Lawrence Berkeley National Laboratory, and to our corporate sponsors, Cray, IBM, Intel, and SGI, for their support. We would like to extend special thanks also to our plenary speakers, technical speakers, poster presenters, and panelists for all of their efforts on behalf of SciDAC 2005 and for their remarkable achievements and contributions. We would like to express our deep appreciation to Lali Chatterjee, Graham Douglas and Margaret Smith of Institute of Physics Publishing, who worked tirelessly in order to provide us with this finished volume within two months, which is nothing short of miraculous. Finally, we wish to express our heartfelt thanks to Michael Strayer, SciDAC Director, whose vision it was to focus SciDAC 2005 on scientific discovery, around which all of the excitement we experienced revolved, and to our DOE SciDAC program managers, especially Fred Johnson, for their support, input, and help throughout.

  19. EDITORIAL: Colloidal suspensions Colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Petukhov, Andrei; Kegel, Willem; van Duijneveldt, Jeroen

    2011-05-01

    Colloid-polymer mixtures and depletion interactions Phase stability of a reversible supramolecular polymer solution mixed with nanospheres Remco Tuinier When depletion goes critical Roberto Piazza, Stefano Buzzaccaro, Alberto Parola and Jader Colombo Tuning the demixing of colloid-polymer systems through the dispersing solvent E A G Jamie, R P A Dullens and D G A L Aarts Polydispersity effects in colloid-polymer mixtures S M Liddle, T Narayanan and W C K Poon Colloidal dynamics and crystallization Crystallization and aging in hard-sphere glasses C Valeriani, E Sanz, E Zaccarelli, W C K Poon, M E Cates and P N Pusey Real-time monitoring of complex moduli from micro-rheology Taiki Yanagishima, Daan Frenkel, Jurij Kotar and Erika Eiser Brownian motion of a self-propelled particle B ten Hagen, S van Teeffelen and H Löwen Crystallization in suspensions of hard spheres: a Monte Carlo and molecular dynamics simulation study T Schilling, S Dorosz, H J Schöpe and G Opletal Structural signature of slow dynamics and dynamic heterogeneity in two-dimensional colloidal liquids: glassy structural order Takeshi Kawasaki and Hajime Tanaka

  20. Obituary: E. Dorrit Hoffleit, 1907-2007

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia

    2007-12-01

    American Association of Variable Star Observers, where MMO papers still turn up, though perhaps not so many as in Dorrit's day. She would also continue education and public outreach activities in the local community that her predecessor, Margaret Harwood, had established. Summer research experience for undergraduate opportunities have become common, but they were rare in 1957, especially for women students, and the ones who came to MMO (more than one hundred over her term) were undoubtedly very strongly motivated. They left even more so, with the striking result that about 25 of the Hoffleit students became professional astronomers. A few of the earliest are now retired; many remain in stellar astronomy, but others have spread across the Solar System and the galaxies. According to a list compiled by Dorrit, with minor additions, these are, in chronological order: Margo Friedel Aller, Andrea Knudsen Dupree, Barbara Welther, Gretchen Luft Hagen Harris, Nancy Houk, Martha Safford Hanner, Diane Reeve Moorhead, Nancy Remage Evans, Catherine Doremus Garmany, Jane Turner, Jean Warren Goad, Karen Alper Castle, Marcia Keyes Rieke, Judy Karpen, Karen Kwitter, Esther Hu, Bonnie Buratti, Harriet Dinerstein, Melissa McGrath, Constance Phillips Walker, John Briggs, Deborah Crocker, Edward Morgan, and Karen Meech. The program went co-ed shortly before Dorrit handed it over to Emilia Belaserne). A special paragraph must go to Janet Akyüz Mattei. She came to MMO in the summer of 1969 upon the recommendation of Paris Pismis, an Armenian-Turkish-Mexican astronomer who had known Janet in Turkey and was a very old friend of Dorrit's (and of mine). Janet's own obituary sadly appeared in these pages (BAAS, 36, pp. 1681-82, 2004), the last 30 of her only 61 years having been spent as the director of AAVSO. Among the many important things Janet did in that directorial capacity was to persuade Dorrit Hoffleit to write up the story of her life for publication by AAVSO in 2002, from which much of