Sample records for su-8 microcontainers maintained

  1. Polymeric microcontainers improve oral bioavailability of furosemide. (United States)

    Nielsen, Line Hagner; Melero, Ana; Keller, Stephan Sylvest; Jacobsen, Jette; Garrigues, Teresa; Rades, Thomas; Müllertz, Anette; Boisen, Anja


    Microcontainers with an inner diameter of 223 μm are fabricated using the polymer SU-8, and evaluated in vitro, in situ and in vivo for their application as an advanced oral drug delivery system for the poorly water soluble drug furosemide. An amorphous sodium salt of furosemide (ASSF) is filled into the microcontainers followed by applying a lid using Eudragit L100. It is possible to control the drug release in vitro, and in vitro absorption studies show that the microcontainers are not a hindrance for absorption of ASSF. In situ perfusion studies in rats are performed with ASSF-filled microcontainers coated with Eudragit and compared to a furosemide solution. The absorption rate constant of ASSF confined in microcontainers is found to be significantly different from the solution, and by light microscopy, it is observed that the microcontainers are engulfed by the intestinal mucus. An oral bioavailability study in rats is performed with ASSF confined in microcontainers coated with Eudragit and a control group with ASSF in Eudragit-coated capsules. A relative bioavailability of 220% for the ASSF in microcontainers compared to ASSF in capsules is found. These studies indicate that the microcontainers could serve as a promising oral drug delivery system. Copyright © 2016. Published by Elsevier B.V.

  2. Microcontainers - an oral drug delivery system for poorly soluble drugs

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Petersen, Ritika Singh; Marizza, Paolo

    with polyvinylpyrrolidone (PVP) by inkjet printing followed by supercritical CO2 impregnation of ketoprofen into the PVP matrix. As an alternative filling method, the powder of amorphous sodium salt of furosemide, (ASSF) was filled into the SU-8 microcontainers. The PLLA microcontainers were filled with drug formulation...... by embossing the microcontainers into a polycaprolactone (PCL) and furosemide (4:1 w/w) layer. For the ASSF-filled microcontainers, an enteric-resistant lid of Eudragit L100 was spray coated onto the cavity of the microcontainers. From coated ASSF-filled microcontainers, a fast release in simulated intestinal...... medium at pH 6.5 was observed. In situ intestinal perfusions were performed in rats of the Eudragit-coated ASSF-filled microcontainers and compared to a furosemide solution. At the end of the study, the small intestine was harvested from the rat and imaged under a light microscope. The absorption rate...

  3. Polymeric microcontainers improve oral bioavailability of furosemide

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Melero, Ana; Keller, Stephan Sylvest


    Microcontainers with an inner diameter of 223μm are fabricated using the polymer SU-8, and evaluated in vitro, in situ and in vivo for their application as an advanced oral drug delivery system for the poorly water soluble drug furosemide. An amorphous sodium salt of furosemide (ASSF) is filled...... with Eudragit and compared to a furosemide solution. The absorption rate constant of ASSF confined in microcontainers is found to be significantly different from the solution, and by light microscopy, it is observed that the microcontainers are engulfed by the intestinal mucus. An oral bioavailability study...

  4. In vitro characterization of microcontainers as an oral drug delivery system

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Keller, Stephan Sylvest; Petersen, Ritika Singh

    We here present in vitro studies showing the promise of microcontainers (fabricated in either SU-8 or Poly(lactic acid) (PLLA)) as an oral drug delivery system for the poorly watersoluble drug, furosemide.......We here present in vitro studies showing the promise of microcontainers (fabricated in either SU-8 or Poly(lactic acid) (PLLA)) as an oral drug delivery system for the poorly watersoluble drug, furosemide....

  5. Spray coating of microcontainers with eudragit using ferromagnetic shadow masks for controlled oral release of poorly water soluble drugs

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Keller, Stephan Sylvest; Boisen, Anja


    of controlling the drug release of poorly soluble drugs from the microcontainers. METHODS: Cylindrical microcontainers (inner diameter of 240 μm) were fabricated in SU-8, using photolithography on silicon substrate. The microcontainers were filled with either cinnarizine (weak base) or amorphous furosemide salt...... clamping to the substrate and therefore precise deposition of the polymer on the microcontainers to form a lid. The release of cinnarizine and amorphous furosemide salt from the coated microcontainers was performed in fasted biorelevant gastric (pH 1.6) and intestinal media (pH 6.5), respectively. RESULTS....... It was possible to control the drug release of cinnarizine by using Eudragit L-100 in the gastric medium and also possible to control the release of amorphous furosemide salt by the Eudragit E-100 coating in the intestinal medium. CONCLUSIONS: The ferromagnetic shadow masks made it possible to deposit a lid...

  6. SU-8 cantilever chip interconnection

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; Janting, Jakob; Schultz, Peter


    The polymer SU-8 is becoming widely used for all kinds of micromechanical and microfluidic devices, not only as a photoresist but also as the constitutional material of the devices. Many of these polymeric devices need to include a microfluidic system as well as electrical connection from...... the electrodes on the SU-8 chip to a printed circuit board. Here, we present two different methods of electrically connecting an SU-8 chip, which contains a microfluidic network and free-hanging mechanical parts. The tested electrical interconnection techniques are flip chip bonding using underfill or flip chip...... bonding using an anisotropic conductive film (ACF). These are both widely used in the Si industry and might also be used for the large scale interconnection of SU-8 chips. The SU-8 chip, to which the interconnections are made, has a microfluidic channel with integrated micrometer-sized cantilevers...

  7. Chemical synthesis on SU-8

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Taveras, Kennedy; Thastrup, Ole


    In this paper we describe a highly effective surface modification of SU-8 microparticles, the attachment of appropriate linkers for solid-supported synthesis, and the successful chemical modification of these particles via controlled multi-step organic synthesis leading to molecules attached...

  8. Synthesis of magnetic thermosensitive microcontainers for enzyme immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianzhi; Zhao, Guanghui, E-mail:; Wang, Xinyu, E-mail:; Peng, Xiaomen; Li, Yanfeng, E-mail: [Lanzhou University, State Key Laboratory of Applied Organic Chemistry, Institute of Biochemical Engineering & Environmental Technology, College of Chemistry and Chemical Engineering (China)


    We present a new approach for the fabrication of magnetic thermoresponsive polymer microcapsules with mobile magnetic spherical cores. The microcontainers form fried-egg-like structures with a polymer shell layer of 50 nm due to the existence of hollow cavities. The microcontainers undergo a temperature-induced volume phase transition upon changing the temperature and present an impressive magnetic response. The magnetic saturation of these smart microcontainers (42 emu/g) is high enough to meet most requirements of bioapplications. To further investigate the potential application of these smart microcontainers in biotechnology, Candida rugosa lipase was selected for the enzyme immobilization process. The immobilized lipase exhibited excellent thermal stability and reusability in comparison with the free enzyme. The adsorption/release of the lipase from the microcontainers can be controlled by the environmental temperature and magnetic force, thus, offering new potential applications such as in controlled drug delivery, bioseparation, and catalysis.

  9. Further outgassing studies on SU-8

    NARCIS (Netherlands)

    Melai, J.; Blanco Carballo, V.M.; Salm, Cora; Wolters, Robertus A.M.; Schmitz, Jurriaan


    SU-8 is often used as a structural material in microsystems. In this work the outgassing characteristics from such cross-linked SU-8 layers are studied using Mass Spectrometry and Gas Chromatography techniques. With these methods the composition of the released matter can be identified, also the

  10. SU-8 Based Piezoresistive Mechanical Sensor

    DEFF Research Database (Denmark)

    Thaysen, Jacob; Yalcinkaya, Arda Deniz; Vestergaard, R.K.


    We present the first SU-8 based piezoresistive mechanical sensor. Conventionally, silicon has been used as a piezoresistive material due to its high gauge factor and thereby high sensitivity to strain changes in a sensor. By using the fact that SU-8 is much softer than silicon and that a gold...

  11. Volume Hologram Formation in SU-8 Photoresist

    Directory of Open Access Journals (Sweden)

    Tina Sabel


    Full Text Available In order to further understand the mechanism of volume hologram formation in photosensitive polymers, light-induced material response is analyzed in commonly used epoxy-based negative photoresist Epon SU-8. For this purpose, time-resolved investigation of volume holographic grating growth is performed in the SU-8 based host–guest system and in the pure SU-8 material, respectively. The comparison of grating growth curves from doped and undoped system allows us to draw conclusions on the impact of individual components on the grating formation process. The successive formation of transient absorption as well as phase gratings in SU-8 is observed. Influence of exposure duration and UV flood cure on the grating growth are investigated. Observed volume holographic grating formation in SU-8 can be explained based on the generation and subsequent diffusion of photoacid as well as time-delayed polymerization of exposed and unexposed areas.

  12. Loading of microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Marizza, Paolo

    The pharmaceutical research is facing several obstacles in the development of drug products for the oral delivery. The main problem deals with the intrinsic chemical nature of the new drug candidates, which are often poorly soluble and barely absorbed in the gastro-intestinal tract. Furthermore......, they are usually degraded before they are absorbed. These combined factors considerably reduce the bioavailability of many active ingredients. Several strategies have been developed to overcome these challenges. One of them are microfabricated drug delivery devices. Microreservoir based-systems are characterized...... by small dimensions (100-500 μm), mucoadhesive properties, asymmetric geometry and unidirectional drug release. In the fabrication of these microcontainers, an important task is the drug loading. The state of the art in this field is based on traditional methods used in microtechnology, which...

  13. Diffusion of water into SU-8 microcantilevers

    DEFF Research Database (Denmark)

    Liu, C.J.; Liu, Y.; Sokuler, M.


    We present a method to monitor the diffusion of liquid molecules in polymers. A microdrop of water is deposited by a piezoelectric drop generator onto the upper surface of a cantilever made of SU-8 based photoresist. In response, the cantilever bends in the opposite direction. We find that this b...... sophisticated finite element model the diffusion coefficient of water in the SU-8 polymer can be determined quantitatively from the dynamics of cantilever bending.......We present a method to monitor the diffusion of liquid molecules in polymers. A microdrop of water is deposited by a piezoelectric drop generator onto the upper surface of a cantilever made of SU-8 based photoresist. In response, the cantilever bends in the opposite direction. We find...... that this bending is mainly caused by the diffusion of water into the cantilever and the consequent swelling of SU-8. Using a one-dimensional diffusion model and assuming a simple swelling law, we qualitatively model the bending of the cantilever during in and out diffusion of water in SU-8. With a more...

  14. From concept to in vivo testing: Microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Mazzoni, Chiara; Tentor, Fabio; Andersen, Sophie Strindberg


    This work explores the potential of polymeric micrometer sized devices (microcontainers) as oral drug delivery systems (DDS). Arrays of detachable microcontainers (D-MCs) were fabricated on a sacrificial layer to improve the handling and facilitate the collection of individual D-MCs. A model drug...

  15. Fabrication of poly (lactic-co-glycolic acid) microcontainers using solvent evaporation with polydimethylsiloxane stencil (United States)

    Kim, Chul Min; Byul Lee, Han; Kim, Jong Uk; Kim, Gyu Man


    We present a fabrication method using polydimethylsiloxane (PDMS) stencils and solvent evaporation to prepare microcontainers with a desired shape made from a biodegradable polymer. Poly(lactic-co-glycolic acid) (PLGA) was used for preparing microcontainers, but most polymers are applicable in the proposed method in which solvent evaporation is used to construct microstructures in confined spaces in the stencil. Microcontainers with various shapes were fabricated by controlling the stencil geometry. Furthermore, a porous structure could be prepared in a micromembrane using water porogen. The porous structure was observed using a field emission scanning electron microscope and mass transfer across the porous membrane was examined using a fluorescent dye. The flexibility of the PDMS stencil allowed the fabrication of microcontainers on a curved surface. Finally, it was demonstrated that microcontainers can be used to contain a localized cell culture. The viability and morphology of cultured cells were observed using confocal microscopy over a period of 3 weeks.

  16. Fabrication and loading of oral drug delivery microcontainers using hot punching

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh; Borre, Mads T.; Keller, Stephan Sylvest


    In this paper, poly-l-lactic acid (PLLA) solution is spin coated to achieve a PLLA layer of 55 μm thickness. Hot punching with a Ni stamp is optimized to fabricate microcontainers in PLLA. Process optimization of thermal bonding of the microcontainers to a poly acrylic acid (PAA) layer is perform...... by modifying sample preparation and varying temperature. The fabricated microcontainers are loaded by hot punching in a spin coated drug polymer film of furosemide and poly-e-caprolactone (PCL)....

  17. Functionalized SU-8 patterned with X-ray Lithography

    DEFF Research Database (Denmark)

    Balslev, Søren; Romanato, F.


    spontaneous emission light source that couples out light normal to the chip plane. In addition we examine the influence of the x-ray irradiation on the fluorescence of thin films of dye doped SU-8. The dye embedded in the SU-8 is optically excited during, characterization by an external light source tuned...

  18. Biodegradable microcontainers as an oral drug delivery system for poorly soluble drugs

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Nagstrup, Johan; Keller, Stephan Sylvest


    of PLLA was produced by spin coating. The film was heated above the polymer glass transition temperature (Tg), and a stamp was forced into the film. Following cooling of the film the stamp was removed, exposing the formed microcontainers. Microcontainers were filled with amorphous furosemide sodium salt...... (produced by spray drying) using a simplified version of a screen printing technique. An enteric-resistant lid of Eudragit L-100 was subsequently spray coated onto the cavity of the microcontainers. Release of amorphous furosemide salt from the coated microcontainers was investigated using a μ-Diss profiler....... Release experiments were carried out in biorelevant gastric medium (pH 1.6) for 2 h, followed by 3 h in a biorelevant intestinal medium (pH 6.5). Moreover, biorelevant flow through dissolution was also carried out in conjunction with UV imaging to visualize the release of amorphous furosemide salt from...

  19. Innovative SU-8 Lithography Techniques and Their Applications

    Directory of Open Access Journals (Sweden)

    Jeong Bong Lee


    Full Text Available SU-8 has been widely used in a variety of applications for creating structures in micro-scale as well as sub-micron scales for more than 15 years. One of the most common structures made of SU-8 is tall (up to millimeters high-aspect-ratio (up to 100:1 3D microstructure, which is far better than that made of any other photoresists. There has been a great deal of efforts in developing innovative unconventional lithography techniques to fully utilize the thick high aspect ratio nature of the SU-8 photoresist. Those unconventional lithography techniques include inclined ultraviolet (UV exposure, back-side UV exposure, drawing lithography, and moving-mask UV lithography. In addition, since SU-8 is a negative-tone photoresist, it has been a popular choice of material for multiple-photon interference lithography for the periodic structure in scales down to deep sub-microns such as photonic crystals. These innovative lithography techniques for SU-8 have led to a lot of unprecedented capabilities for creating unique micro- and nano-structures. This paper reviews such innovative lithography techniques developed in the past 15 years or so.

  20. Supercritical impregnation of polymer matrices spatially confined in microcontainers for oral drug delivery: Effect of temperature, pressure and time

    DEFF Research Database (Denmark)

    Marizza, Paolo; Pontoni, L.; Rindzevicius, Tomas


    The present study is aimed to enhance the oral bioavailability of ketoprofen by inserting it into the matrixof poly(vinylpyrrolidone) (PVP) K10 spatially confined into microcontainers, by means of supercriticalCO2-aided impregnation. Microcontainers are cylindrical reservoirs, with typical sizes...... sol-ubility in water. In a previous study we introduced a novel technique for drug loading of microcontainers,based on inkjet printing and supercritical impregnation (SCI). We showed that SCI produces accurate andreproducible drug loading for large arrays of microcontainers. In the attempt...... parameters(temperature, pressure, time, drug concentration in the supercritical phase) was elucidated with respectto the loading capacity. The microcontainer filling was observed by means of optical macroimaging, X-ray microtomography and scanning electron microscopy. The physical state of the drug...

  1. SU-8 as a Material for Microfabricated Particle Physics Detectors

    CERN Document Server

    Maoddi, Pietro; Jiguet, Sebastien; Renaud, Philippe


    Several recent detector te chnologies developed for particle physics applications are based on microfabricated structures. Dete ctors built with this approach generally exhibit the overall best performance in te rms of spatial and time resolution. Many properties of the SU-8 photoepoxy make it suitable for the manufacturing of microstructured particle detectors. This arti cle aims to review some emerging detector technologies making use of SU-8 microstructu ring, namely micropatte rn gaseous detectors and microfluidic scintillation detectors. Th e general working principle and main process steps for the fabrication of each device are reported, with a focus on the advantages brought to the device functionality by the us e of SU-8. A novel process based on multiple bonding steps for the fabrication of thin multila yer microfluidic scin tillation detectors developed by the authors is presented. Finally, a brief overview of the applications for the discussed devices is given.

  2. Development of untethered SU-8 polymer scratch drive microrobots

    KAUST Repository

    Valencia Garcia, Manuel


    This paper presents the design, simulation, fabrication and testing of novel, untethered SU-8 polymer microrobots based on scratch drive actuators (SDAs). The design consists of two 100×120×10μm linked SDAs, individually operated close to their resonant frequencies. The resonant frequency and deflection behavior of an individual SDA can be controlled by its shape, thickness, and stiffening design features. As a result, paired SDAs can be actuated individually or simultaneously by a multifrequency driving signal, allowing for two-dimensional displacement. The fabrication process uses SU-8 as structural material and PMGI as sacrificial material. The SU-8 provides a flexible material for the SDA\\'s plates as well as the bushing. Finally, a Cr/Au layer is blanket deposited to provide electrical conductivity.

  3. SU-8 Photolithography as a Toolbox for Carbon MEMS

    Directory of Open Access Journals (Sweden)

    Rodrigo Martinez-Duarte


    Full Text Available The use of SU-8 as precursor for glass-like carbon, or glassy carbon, is presented here. SU-8 carbonizes when subject to high temperature under inert atmosphere. Although epoxy-based precursors can be patterned in a variety of ways, photolithography is chosen due to its resolution and reproducibility. Here, a number of improvements to traditional photolithography are introduced to increase the versatility of the process. The shrinkage of SU-8 during carbonization is then detailed as one of the guidelines necessary to design carbon patterns. A couple of applications—(1 carbon-electrode dielectrophoresis for bioparticle manipulation; and (2 the use of carbon structures as micro-molds are also presented.

  4. Droplet backside exposure for making slanted SU-8 microneedles. (United States)

    Kwon, Ki Yong; Bi, Xiaopeng; Li, Wen


    This paper presented a droplet backside exposure (DBE) method for making slanted microneedle structures on a flexible polymer substrate. To demonstrate the feasibility of the DBE approach, SU-8 microneedle arrays were fabricated on polydimethylsiloxane (PDMS) substrates. The length of the microneedles was controlled by tuning the volume of the SU-8 droplet, utilizing the wetting barrier phenomenon at a liquid-vapor-hydrophilic surface-hydrophobic surface interface. The experimental results showed excellent repeatability and controllability of the DBE method for microneedle fabrication. Analytical models were also studied to predict the dimensions of the microneedles, which agreed with the experimental data.

  5. SU-8 microfluidic device for scintillating particle detection

    CERN Document Server

    Mapelli, A; Haguenauer, M; Jiguet, S; Vico Triviño, N; Renaud, P


    This paper presents the study of a novel scintillation detector based on standard microfabrication techniques. It consists of a fine pitch array of hollow waveguides filled with a liquid scintillator and optically coupled to photodetectors. The detector has been fabricated by patterning the SU-8 photoresist on silicon wafers. Experimental studies have been performed by exciting the liquid scintillator contained in the SU-8 waveguides with electrons. The scintillation light produced was read out by an external photodetector. The results obtained with this set-up demonstrate the concept of microfluidic scintillation detection and are very encouraging for future developments.

  6. A High-Throughput SU-8Microfluidic Magnetic Bead Separator

    DEFF Research Database (Denmark)

    Bu, Minqiang; Christensen, T. B.; Smistrup, Kristian


    We present a novel microfluidic magnetic bead separator based on SU-8 fabrication technique for high through-put applications. The experimental results show that magnetic beads can be captured at an efficiency of 91 % and 54 % at flow rates of 1 mL/min and 4 mL/min, respectively. Integration of s...

  7. Special Issue: 15 Years of SU8 as MEMS Material

    Directory of Open Access Journals (Sweden)

    Arnaud Bertsch


    Full Text Available In 1997, the first paper using SU-8 as a material for microfabrication was published [1], demonstrating the interest of this negative photoresist for the near-UV structuration of thick layers and the manufacturing of high aspect-ratio components.[...

  8. Multiplex polymerase chain reaction (PCR) on a SU-8 chip

    DEFF Research Database (Denmark)

    Christensen, Troels Balmer; Bang, Dang Duong; Wolff, Anders


    We present the detection of Campylobacter at species level using multiplex PCR in a micro fabricated PCR chip. The chip is based on the polymer SU-8 that allows integration with different microfluidic components, e.g., sample pre-treatment before PCR, and DNA detection simultaneously with or afte...

  9. Moisture resistance of SU-8 and KMPR as structural material

    NARCIS (Netherlands)

    Blanco Carballo, V.M.; Melai, J.; Salm, Cora; Schmitz, Jurriaan


    This paper treats the moisture resistance of SU-8 and KMPR, two photoresists considered as structural material in microsystems. Our experiments focus on the moisture resistance of newly developed radiation imaging detectors containing these resists. Since these microsystems will be used unpackaged,

  10. SU-8 negative photoresist for optical mask manufacturing (United States)

    Bogdanov, Alexei L.


    The requirements for better control, linearity, and uniformity of critical dimension (CD) on photomasks in fabrication of 180 and 150 nm generation devices result in increasing demand for thinner, more etching durable, and more sensitive e-beam resists. Novolac based resists with chemical amplification have been a choice for their sensitivity and stability during etching. However, difficult CD control due to the acid catalyzer diffusion and quite narrow post exposure bake (PEB) process window are some of the major drawbacks of these resists. SU-8 is recently introduced to the market negative photoresist. High sensitivity, fairly good adhesion properties, and relatively simple processing of SU-8 make it a good substitution for novolac based chemically amplified negative e-beam resists in optical mask manufacturing. The replacement of traditional chemically amplified resists by SU- 8 can increase the process latitude and reduce resist costs. Among the obvious drawbacks of SU-8 are the use of solvent- based developer and demand of oxygen plasma for resist removal. In this paper the use of SU-8 for optical mask manufacturing is reported. All steps of resist film preparation, exposure and development are paid a share of attention. Possibilities to use reactive ion etching (RIE) with oxygen in order to increase resist mask contrast are discussed. Special exposure strategy (pattern outlining) was employed to further improve the edge definition. The resist PEB temperature and time were studied to estimate their weight in overall CD control performance. Specially designed test patterns with 0.25 micrometer design rule could be firmly transferred into a chromium layer both by wet etching and ion milling. Influence of exposure dose variation on the pattern CD change was studied.

  11. SU-8-based microneedles for in vitro neural applications (United States)

    Altuna, Ane; Gabriel, Gemma; Menéndez de la Prida, Liset; Tijero, María; Guimerá, Anton; Berganzo, Javier; Salido, Rafa; Villa, Rosa; Fernández, Luis J.


    This paper presents novel design, fabrication, packaging and the first in vitro neural activity recordings of SU-8-based microneedles. The polymer SU-8 was chosen because it provides excellent features for the fabrication of flexible and thin probes. A microprobe was designed in order to allow a clean insertion and to minimize the damage caused to neural tissue during in vitro applications. In addition, a tetrode is patterned at the tip of the needle to obtain fine-scale measurements of small neuronal populations within a radius of 100 µm. Impedance characterization of the electrodes has been carried out to demonstrate their viability for neural recording. Finally, probes are inserted into 400 µm thick hippocampal slices, and simultaneous action potentials with peak-to-peak amplitudes of 200-250 µV are detected.

  12. SU-8 Guiding Layer for Love Wave Devices

    Directory of Open Access Journals (Sweden)

    Michael I. Newton


    Full Text Available SU-8 is a technologically important photoresist used extensively for thefabrication of microfluidics and MEMS, allowing high aspect ratio structures to beproduced. In this work we report the use of SU-8 as a Love wave sensor guiding layerwhich allows the possibility of integrating a guiding layer with flow cell during fabrication.Devices were fabricated on ST-cut quartz substrates with a single-single finger design suchthat a surface skimming bulk wave (SSBW at 97.4 MHz was excited. SU-8 polymer layerswere successively built up by spin coating and spectra recorded at each stage; showing afrequency decrease with increasing guiding layer thickness. The insertion loss andfrequency dependence as a function of guiding layer thickness was investigated over thefirst Love wave mode. Mass loading sensitivity of the resultant Love wave devices wasinvestigated by deposition of multiple gold layers. Liquid sensing using these devices wasalso demonstrated; water-glycerol mixtures were used to demonstrate sensing of density-viscosity and the physical adsorption and removal of protein was also assessed usingalbumin and fibrinogen as model proteins.

  13. SU-8 Cantilever Sensor with Integrated Read-Out

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte


    kan måles med optiske målesystemer eller ved hjælp af integrerede piezoresistorer. Dette PhD projekt beskriver design, fremstilling og indpakning af en polymer cantilever chip med piezoresistive udlæsning. Chippen er fremstillet i den epoxy-baserede negative fotoresist SU-8, på nær de integrerede guld...... resistorer. Cantilever baserede sensorer bliver normalt fremstillet i silicium men fordelen ved at bruge SU-8 er, at SU-8 er et blødere materiale som er billigere og hurtigere at fremstille. For at opnå elektrisk kontakt fra chippen til et printet kredsløbskort, er flere metoder så som flip-chip bonding...... blevet undersøgt. Chippen er blevet brugt til overfladestress målinger i væske, så som thiol binding og detektion af pH forandringer. Teoretiske beregninger af følsomheden for overfladestress og den mindste målbare overfladestress bliver også beskrevet. Til sidst diskuteres muligheden for at binde...

  14. Hot embossing and mechanical punching of biodegradable microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh; Mahshid, Rasoul; Andersen, Nis Korsgaard


    the holes, after filling them with drug. Here, we demonstrate the fabrication of microcontainers with a diameter of 340 lm and a height of 50 lm. The process is temperature benign so that the compositional integrity of the drug is preserved. It also provides a good flexibility for creating different sizes...

  15. Improved anti-stiction coating of SU-8 molds

    DEFF Research Database (Denmark)

    Lange, Jacob Moresco; Clausen, Casper Hyttel; Svendsen, Winnie Edith


    We have developed a simple method for the improved release of embossed poly(methyl methacrylate) (PMMA) as well as casted poly(dimethyl siloxane) (PDMS) from a SU-8 mold using vapor phase deposition of 1H,1H,2H,2H-Perfluorodecyltrichlorosilane (FDTS). We have further investigated if prior breakage...... the method for the mold fabrication as well as the vapor phase deposition of FDTS onto the mold is described; examples of released final devices using this method in PMMA and PDMS are presented. (C) 2010 Elsevier B.V. All rights reserved....

  16. SU-8 etching in inductively coupled oxygen plasma

    DEFF Research Database (Denmark)

    Rasmussen, Kristian Hagsted; Keller, Stephan Sylvest; Jensen, Flemming


    Structuring or removal of the epoxy based, photo sensitive polymer SU-8 by inductively coupled plasma reactive ion etching (ICP-RIE) was investigated as a function of plasma chemistry, bias power, temperature, and pressure. In a pure oxygen plasma, surface accumulation of antimony from the photo......-initiator introduced severe roughness and reduced etch rate significantly. Addition of SF6 to the plasma chemistry reduced the antimony surface concentration with lower roughness and higher etch rate as an outcome. Furthermore the etch anisotropy could be tuned by controlling the bias power. Etch rates up to 800 nm...

  17. Fabrication of high-aspect ratio SU-8 micropillar arrays

    DEFF Research Database (Denmark)

    Amato, Letizia; Keller, Stephan S.; Heiskanen, Arto


    to the resolution limit of photolithography. This paper describes process optimization for the fabrication of dense SU-8 micropillar arrays (2.5μm spacing) with nominal height ⩾20μm and nominal diameter ⩽2.5μm (AR ⩾8). Two approaches, differing in temperature, ramping rate and duration of the baking steps were...... compared as part of the photolithographic processing, in order to evaluate the effect of baking on the pattern resolution. Additionally, during the post-processing, supercritical point drying and hard baking were introduced yielding pillars with diameter 1.8μm, AR=11 and an improved temporal stability....

  18. Combined electron beam and UV lithography in SU-8

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Thamdrup, Lasse Højlund; Mironov, Andrej


    We present combined electron beam and UV lithography (CEUL) in SU-8 as a fast and flexible lithographic technique for prototyping of functional polymer devices and pattern transfer applications. CEUL is a lithographic technique suitable for defining both micrometer and nanometer scale features...... in a single polymer film on the wafer scale. The height of the micrometer and nanometer scale features is matched within 30 nm. As a pattern transfer application, we demonstrate stamp fabrication and thermal nanoimprint of a 2-dimensional array of 100 nm wide lines with a pitch of 380 nm in connection...

  19. Microcontainers as an oral delivery system for spray dried cubosomes containing ovalbumin

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Rades, Thomas; Boyd, Ben


    microcontainers intended as an oral drug delivery system. The cubosomes consisted of commercial glyceryl monooleate, Dimodan®, containing OVA and were surrounded with a dextran shell prepared by spray drying. Cryo-TEM was used to confirm that cubosomes were formed after hydration of the spray dried precursor......The purpose of this study was to prepare cubosomes encapsulating the model antigen ovalbumin (OVA) via spray drying, and to characterise such cubosomes with a view for their potential application in oral vaccine delivery. Furthermore the cubosome formulation was loaded into polymeric...... the cubosomes and microcontainers occurred at pH 6.8, releasing 44.1±5.6% of the OVA in 96h. Small-angle X-ray scattering (SAXS) revealed that the 'dry' particles possessed an internal ordered lipid structure (lamellar and inverse micellar phase) by virtue of a small amount of residual water, and after...

  20. Fabrication of SU-8 low frequency electrostatic energy harvester

    KAUST Repository

    Ramadan, Khaled S.


    A 1500μm × 1500μm × 150μm out-of-plane, gap closing, electrostatic energy harvester is designed and fabricated to harvest low-frequency ambient vibrations. SU-8 is used to fabricate the proof mass (1200μm × 1200μm × 150μm) and the 5 m springs. Different harvesters were designed to harvest at 50, 75 and 110 Hz. At 110 Hz, Simulations show that with an input vibration of 10 μm amplitude at the frequency of resonance of the structure, the energy harvester should generate an average output power density of 0.032μW/mm3. This is the most area-efficient low-frequency electrostatic harvester to-date. © 2011 IEEE.

  1. High temperature SU-8 pyrolysis for fabrication of carbon electrodes

    DEFF Research Database (Denmark)

    Hassan, Yasmin Mohamed; Caviglia, Claudia; Hemanth, Suhith


    spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon. The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis...... composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance......In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central...

  2. Tailoring the mechanical properties of SU-8/clay nanocomposites: polymer microcantilever fabrication perspective

    CSIR Research Space (South Africa)

    Chen, H


    Full Text Available SU-8/Clay nanocomposite is considered as a candidate material for microcantilever sensor fabrication. Organically modified montmorillonite clay nanoparticles are dispersed in the universally used negative photoresist polymer SU-8, for a low cost...

  3. Gold Nanoparticles-Coated SU-8 for Sensitive Fluorescence-Based Detections of DNA

    DEFF Research Database (Denmark)

    Cao, Cuong; Birtwell, Sam W.; Høgberg, Jonas


    that use fluorescence as the predominant detection workhorse. Here, we show that deposition of a thin gold nanoparticles layer onto the SU-8 surface significantly reduces the autofluorescence of the coated SU-8 surface by as much as 81% compared to bare SU-8. Furthermore, DNA probes can easily...

  4. Functionalization of SU-8 Photoresist Surfaces with IgG Proteins

    DEFF Research Database (Denmark)

    Blagoi, Gabriela; Keller, Stephan Urs; Johansson, Alicia


    The negative epoxy-based photoresist SU-8 has a variety of applications within microelectromechanical systems (MEMS) and lab-on-a-chip systems. Here, several methods to functionalize SU-8 surfaces with IgG proteins were investigated. Fluorescent labeled proteins and fluorescent sandwich immunoass......The negative epoxy-based photoresist SU-8 has a variety of applications within microelectromechanical systems (MEMS) and lab-on-a-chip systems. Here, several methods to functionalize SU-8 surfaces with IgG proteins were investigated. Fluorescent labeled proteins and fluorescent sandwich...... SU-8 in a functional fluorescent sandwich immunoassay detecting C-reactive protein (CRP) gave twice as high signal as compared with the other two surfaces. Immunoassays performed on bare SU-8 and CAN treated SU-8 resulted in detection limits of CRP of 30 and 80 ng/ml respectively which is sufficient...

  5. SU(8) family unification with boson-fermion balance

    CERN Multimedia

    CERN. Geneva


    Grand unification has been intensively investigated for over forty years, and many different approaches have been tried. In this talk I propose a model that involves three ingredients that do not appear in the usual constructions: (1) boson--fermion balance without full supersymmetry, (2) canceling the spin 1/2 fermion gauge anomalies against the anomaly from a gauged spin 3/2 gravitino, and (3) using a scalar field representation with non-zero U(1) generator to break the SU(8) gauge symmetry through a ground state which, before dynamical symmetry breaking, has a periodic U(1) generator structure. The model has a number of promising features: (1) natural incorporation of three families, (2) incorporation of the experimentally viable flipped SU(5) model, (3) a symmetry breaking pathway to the standard model using the scalar field required by boson-fermion balance, together with a stage of most attractive channel dynamical symmetry breaking, without postulating additional Higgs fields, (4) vanishing of bare Yuk...

  6. Fabrication of micropressure sensor using SU-8/silver as piezoresistor and overhead projector transparency as substrate (United States)

    Wong, Wah Seng; Azid, Ishak Abdul; Ibrahim, Kamarulazizi; Devarajan, Mutharasu


    This paper proposes a low-cost SU-8 pressure sensor fabricated using a piezoresistive material, SU-8/silver composite (SU-8/Ag), and a substrate material, overhead projector (OHP) transparency. SU-8/Ag has higher gauge factor (26.3) but shows a lower stiffness (2 GPa) compared with doped silicon. The OHP transparency substrate is cheap, easily forms the desired shape, is transparent to light (allows backside exposure), and allows for the dry release method through OHP transparency. Fabrication and characterization in this study were carried out using a typical semiconductor lab setup. The fabricated sensor showed high sensitivity (21.5 μV/Pa), low linearity error (Pearson's correlation coefficient=0.994937), and no apparent hysteresis response. The fabricated sensor with SU-8/Ag as the piezoresistive material exhibited 41 times higher sensitivity compared to that found in a previous study based on SU-8 and doped polysilicon.

  7. High resolution 100 kV electron beam lithography in SU-8

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Jakobsen, S.; Schmidt, M.S.


    High resolution 100 kV electron beam lithography in thin layers of the negative resist SU-8 is demonstrated. Sub-30 nm lines with a pitch down to 300 nm are written in 100 nm thick SU-8. Two reactive ion etch processes are developed in order to transfer the SU-8 structures into a silicon substrate......, a Soft O-2-Plasma process to remove SU-8 residues on the silicon surface after development and a highly anisotropic SF6/O-2/CHF3 based process to transfer the pattern into a silicon substrate, with selectivity between silicon and SU-8 of approximately 2. 30 nm lines patterned in SU-8 are successfully...

  8. A Simple Hydrophilic Treatment of SU-8 Surfaces for Cell Culturing and Cell Patterning

    DEFF Research Database (Denmark)

    Wang, Zhenyu; Stangegaard, Michael; Dufva, Hans Martin


    SU-8, an epoxy-based photoresist, widely used in constitution different mTAS systems, is incompatible with mammalian cell adhesion and culture in its native form. Here, we demonstrate a simple, cheap and robust two-step method to render a SU-8 surface hydrophilic and compatible with cell culture........ The contact angle of SU-8 surface was significantly reduced from 90° to 25° after the surface modification. The treated SU-8 surfaces provided a cell culture environment that was comparable with cell culture flask surface in terms of generation time and morphology....

  9. Microcontainers as an oral delivery system for spray dried cubosomes containing ovalbumin

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Rades, Thomas; Boyd, Ben


    The purpose of this study was to prepare cubosomes encapsulating the model antigen ovalbumin (OVA) via spray drying, and to characterise such cubosomes with a view for their potential application in oral vaccine delivery. Furthermore the cubosome formulation was loaded into polymeric microcontain......The purpose of this study was to prepare cubosomes encapsulating the model antigen ovalbumin (OVA) via spray drying, and to characterise such cubosomes with a view for their potential application in oral vaccine delivery. Furthermore the cubosome formulation was loaded into polymeric...

  10. Single-mode waveguides with SU-8 polymer core and cladding for MOEMS applications

    DEFF Research Database (Denmark)

    Nordström, Maria; Zauner, Dan; Boisen, Anja


    Fabrication and optical characterization of singlemode polymeric embedded waveguides are performed. A specific material combination (SU-8 2005 as core and the modified SU-8 mr-L 6050XP as cladding) is chosen in order to obtain a small refractive index difference for single-mode propagation combin...

  11. Considerations on using SU-8 as a construction material for high aspect ratio structures

    NARCIS (Netherlands)

    Melai, J.; Salm, Cora; Smits, Sander M.; Blanco Carballo, V.M.; Schmitz, Jurriaan; Hageluken, Ben


    This paper discusses two material aspects of SU-8 that have up till now been insufficiently documented. We present initial results on the outgassing behavior and a study on the dielectric properties of SU-8 at high bias voltage. The dielectric strength is determined to be at least 2 MV/cm. These

  12. A Simple Hydrophilic Treatment of SU-8 Surfaces for Cell Culturing and Cell Patterning

    DEFF Research Database (Denmark)

    Wang, Zhenyu; Stangegaard, Michael; Dufva, Hans Martin


    SU-8, an epoxy-based photoresist, widely used in constitution different mTAS systems, is incompatible with mammalian cell adhesion and culture in its native form. Here, we demonstrate a simple, cheap and robust two-step method to render a SU-8 surface hydrophilic and compatible with cell culture...

  13. Novel method for chemical modification and patterning of the SU-8 photoresist

    DEFF Research Database (Denmark)

    Blagoi, Gabriela; Keller, Stephan Urs; Boisen, Anja


    In this paper we describe a new photochemical method to tailor and pattern the surface of SU-8 negative photoresist. Antraquinone (AQ) derivatives were used to chemically modify and pattern SU-8 surfaces. Using AQ derivatives with electophilic moieties (AQ-E), we could chemo-selectively change...... the wetting behaviour of SU-8. The resolution limit of the AQ photopatterning method was 20 μm when using an uncollimated light source. AQ modification followed by a reaction with amino groups of Alexa-647 cadaverine and a Biotin-amino derivative proved possible modification and patterning of polymeric...

  14. A facile micropatterning method for a highly flexible PEDOT:PSS on SU-8

    KAUST Repository

    Cho, Nam Chul


    We report the micropatterning of conducting polymer on the epoxy-based photoresist to demonstrate fully organic, conducting and flexible electrodes. We show that polystyrene sulfonic acid can be covalently linked to the surface of the photoresist (SU-8) by forming sulfonyl ester at the interfaces. We also present an application of the patterned PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate)/SU-8 to the electroplating of metal electrodes. © 2016 Elsevier B.V.

  15. Microfabrication of PDMS microchannels using SU-8/PMMA moldings and their sealing to polystyrene substrates (United States)

    Bubendorfer, Andrea; Liu, Xianming; Ellis, Amanda V.


    In this paper we show increased interfacial bonding of a photoresist (SU-8) deposited onto highly polished poly(methyl methacrylate) (PMMA) substrates containing a UV absorber. We also demonstrate the facile sealing/covalent bonding of 100 µm × 20 µm PDMS replica microchannels, made from these PMMA/SU-8 moldings, onto thermally polymerized styrene. Sealing was achieved through radio-frequency plasma discharge (RFPD) oxygen plasma treatment.

  16. UV-LIGA Microfabrication of 220 GHz Sheet Beam Amplifier Gratings with SU-8 Photoresists (United States)


    etching (DRIE) is not effective on copper substrates, but was used to fabricate metalized silicon test pieces [11]. This paper begins with a detailed...figure 9(b)). After an ultrasonic bath in Microclean 90 R© and water, only half of a dozen blackened bits of SU-8 remained. The remaining SU-8 residue... metallization Master of Science Thesis Dept of Chem. Eng., Case Western Reserve University [22] Pasquale M A, Gassa L M and Arvia A J 2008 Copper

  17. Investigation on the mechanism of nitrogen plasma modified PDMS bonding with SU-8

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chengxin; Yuan, Yong J., E-mail:


    Graphical abstract: - Highlights: • Different nitrogen plasma processes modified PDMS bonding with SU-8 had been studied. • The effect of nitrogen plasma modification would produce the best result and the recovery of PDMS hydrophobicity could be delayed. - Abstract: Polydimethylsiloxane (PDMS) and SU-8 are both widely used for microfluidic system. However, it is difficult to permanently seal SU-8 microfluidic channels using PDMS with conventional methods. Previous efforts of combining these two materials mainly employed oxygen plasma modified PDMS. The nitrogen plasma modification of PDMS bonding with SU-8 is rarely studied in recent years. In this work, the mechanism of nitrogen plasma modified PDMS bonding with SU-8 was investigated. The fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle of a water droplet were used to analyze the nitrogen plasma modified surface and the hydrophilic stability of PDMS samples. Pull-off tests were used for estimating the bonding effect of interface between nitrogen plasma modified PDMS and SU-8.

  18. Polydimethylglutarimide (PMGI) as a sacrificial material for SU-8 surface-micromachining (United States)

    Foulds, I. G.; Johnstone, R. W.; Parameswaran, M.


    SU-8 is finding increased use as a structural polymer MEMS material due to its biocompatibility, mechanical properties and low cost. The goal of this work is to expand the use of SU-8 through the creation of SU-8-based surface-micromachining processes that use polydimethylglutarimide (PMGI) as a sacrificial layer. PMGI is a deep-UV positive resist, used mainly for bilayer lift-off processes. PMGI is a good sacrificial layer candidate, as it is spinable at a wide variety of thicknesses, is photopatternable and has a glass transition temperature greater than the processing temperatures required for SU-8. PMGI is shown to be useful as a sacrificial layer for SU-8 surface micromachining processes with one freestanding layer with patterned metal, single-layer devices with more than one thickness, and two layer devices. Two classes of devices were fabricated with the developed processes. The first class of devices are compliant mechanisms, including bent-beam actuators, thermal isolation platforms and out-of-plane grippers. The second class of devices fabricated are freely moving devices such as hinged plates and gears, which require the use of true kinematic joints, such as scissor hinges, staple hinges and pin joints.

  19. Novel SU-8 based vacuum wafer-level packaging for MEMS devices

    DEFF Research Database (Denmark)

    Murillo, Gonzalo; Davis, Zachary James; Keller, Stephan Urs


    This work presents a simple and low-cost SU-8 based wafer-level vacuum packaging method which is CMOS and MEMS compatible. Different approaches have been investigated by taking advantage of the properties of SU-8, such as chemical resistance, optical transparence, mechanical reliability...... and versatility. A novel technique of wafer level adhesive bonding, which uses SU-8 as structural and adhesive material, has been developed and successfully demonstrated. Optical inspection and SEM images were used in order to measure the package lid bending and probe the encapsulation sealing. In addition......, an indirect vacuum level measurement has been carried out by comparing the different quality factors of a test cantilever resonator when this element is packed or unpacked....

  20. Novel SU-8/Ionic Liquid Composite for Tribological Coatings and MEMS

    Directory of Open Access Journals (Sweden)

    Leili Batooli


    Full Text Available Tribology of SU-8 polymer is increasingly relevant due to bursting use of this material in a variety of applications. This study is directed towards introduction and investigation of a novel self-lubricating composite of an ionic liquid (IL in SU-8. The new material can be utilized for fabrication of lubricating polymer coating with tunable surface properties or SU8-made elements for microelectromechanical systems (MEMS with enhanced tribological performance. It is shown that addition of IL drastically alters water affinity of the composite while UV patternability remains unmodified. A lower coefficient of friction and wear has been obtained for two investigated compositions with 4 and 10 wt % ionic liquid.

  1. A tapered hollow metallic microneedle array using backside exposure of SU-8 (United States)

    Kim, Kabseog; Park, Daniel S.; Lu, Hong M.; Che, Wooseong; Kim, Kyunghwan; Lee, Jeong-Bong; Ahn, Chong H.


    This paper presents a novel fabrication process for a tapered hollow metallic microneedle array using backside exposure of SU-8, and analytic solutions of critical buckling of a tapered hollow microneedle. An SU-8 mesa was formed on a Pyrex glass substrate and another SU-8 layer, which was spun on top of the SU-8 mesa, was exposed through the backside of the glass substrate. An array of SU-8 tapered pillar structures, with angles in the range of 3.1°-5°, was formed on top of the SU-8 mesa. Conformal electrodeposition of metal was carried out followed by a mechanical polishing using a planarizing polymeric layer. All organic layers were then removed to create a metallic hollow microneedle array with a fluidic reservoir on the backside. Both 200 µm and 400 µm tall, 10 by 10 arrays of metallic microneedles with inner diameters of the tip in the range of 33.6-101 µm and wall thickness of 10-20 µm were fabricated. Analytic solutions of the critical buckling of arbitrary-angled truncated cone-shaped columns are also presented. It was found that a single 400 µm tall hollow cylindrical microneedle made of electroplated nickel with a wall thickness of 20 µm, a tapered angle of 3.08° and a tip inner diameter of 33.6 µm has a critical buckling force of 1.8 N. This analytic solution can be used for square or rectangular cross-sectioned column structures with proper modifications.

  2. Immunosensing by luminescence reduction in surface-modified microstructured SU-8

    Energy Technology Data Exchange (ETDEWEB)

    Eravuchira, Pinkie Jacob; Baranowska, Malgorzata; Eckstein, Chris [Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira i Virgili, Avda. Països Catalans 26, Tarragona 43007 (Spain); Díaz, Francesc [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcelí Domingo s/n, Tarragona 43007 (Spain); Llobet, Eduard; Marsal, Lluis F. [Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira i Virgili, Avda. Països Catalans 26, Tarragona 43007 (Spain); Ferré-Borrull, Josep, E-mail: [Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira i Virgili, Avda. Països Catalans 26, Tarragona 43007 (Spain)


    Highlights: • The reduction of photoluminescence of SU-8 upon surface modification is reported. • Micropillar structuring of SU-8 surface results in an increased photoluminescence reduction rate (10% glass, 15% silicon). • Photoluminescence reduction rate can be a transduction parameter for the detection of antibody-antigen binding events. • The proposed sensing mechanism can be used to quantify small concentrations of antibody. • Lower limit of detection (LOD) of 28 μg/ml on silicon substrates and 42 μg/ml on glass substrates was achieved. - Abstract: SU-8, an epoxy based negative photoresist is extensively used as a structural material for the fabrication of microelectro-mechanical systems and in microelectronics technology. However, the possible applications of SU-8 for biosensing have not been explored much, mainly because of the photoluminescence SU-8 possesses in the near-UV and visible wavelength ranges which hinders fluorescent labelling of biorecognition events. In this study we demonstrate that photoluminescence of SU-8 can be employed itself as a sensing transduction parameter to produce a tool for immunosensing: the photoluminescence shows a systematic reduction upon modification of its surface chemistry, and in particular upon attachment of an antigen-antibody (aIgG-IgG) pair. We investigate the relation of the amount of reduction of photoluminescence on planar and microstructured surfaces, and we show that microstructuring leads to a higher reduction than a planar surface. Furthermore, we evaluated the dependence of photoluminescence reduction as a function of analyte concentration to prove that this magnitude can be applied to immunosensing.

  3. Humidity influence on the adhesion of SU-8 polymer from MEMS applications

    Directory of Open Access Journals (Sweden)

    Birleanu Corina


    Full Text Available In this paper, the adhesion behaviors of SU-8 polymer thin film from MEMS application were investigated as a function of relative humidity. The adhesion test between the AFM tip and SU-8 polymer have been extensively studied using the atomic force microscope (AFM, for a relative humidity (RH varying between 20 and 90%. The samples for tests are SU-8 polymers hard baked at different temperatures. The hard bake temperature changes the tribo-mechanical properties of polymers. The paper reports the measurements and the modeling of adhesion forces versus humidity in controlled ranges between 20 to 90%RH. To investigate the effect of relative humidity on adhesion for SU-8 polymer hard baked we used an analytical method which encompasses the effect of capillarity as well as the solid-to-solid interaction. While the capillary force expression is considered to be the sum of the superficial tension and the Laplace force for the solid-solid interaction is expressed by the Derjagin, Muller and Toropov (DMT model of solids adhesion. The analytical results obtained are in accordance with those obtained experimentally.

  4. Moisture resistance of SU-8 and KMPR as structural material for integrated gaseous detectors

    NARCIS (Netherlands)

    Blanco Carballo, V.M.; Melai, J.; Salm, Cora; Schmitz, Jurriaan


    This paper treats the moisture resistance of SU-8 and KMPR, two photoresists considered as structural material in microsystems. Our experiments focus on the moisture resistance of newly developed radiation imaging detectors containing these resists. Since these microsystems will be used unpackaged,

  5. Improved performance of InAs/GaSb strained layer superlattice detectors with SU-8 passivation (United States)

    Kim, H. S.; Plis, E.; Myers, S.; Khoshakhlagh, A.; Gautam, N.; Kutty, M. N.; Sharma, Y. D.; Dawson, L. R.; Krishna, S.


    We report on surface passivation using SU-8 for type-II InAs/GaSb strained layers superlattice (SLS) detectors with a PIN design operating in mid-wave infrared (MWIR) spectral region (λ50% cut-off ~ 4.4 μm). Material growth and characterization, single pixel device fabrication and testing, as well as focal plane array (FPA) processing are described. High quality strain-balanced SLS material with FWHM of 1st SLS satellite peak of 36 arcsec is demonstrated. The electrical and optical performance of devices passivated with SU-8 are reported and compared with those of unpassivated devices. The dark current density of a single pixel device with SU-8 passivation showed four orders of magnitude reduction compared to the device without any passivation. At 77K, the zero-bias responsivity and detectivity are equal to 1.1 A/W and 4 x 1012 Jones at 4μm, respectively, for the SU-8 passivated test pixel on the focal plane array.

  6. Nanochannels in SU-8 with floor and ceiling metal electrodes and integrated microchannels

    NARCIS (Netherlands)

    Nichols, K.P.F.; Eijkel, Jan C.T.; Gardeniers, Johannes G.E.


    Sacrificially etched 2-D nanofluidic channels and nanospaces with integrated floor and ceiling electrodes and arbitrary channel geometries have been demonstrated with channel heights from 20 nm to 400 nm, widths from 800 nm to 40 mm, and lengths up to 3 mm, using SU-8 as the channel structural

  7. Investigation of the bond strength between the photo-sensitive polymer SU-8 and gold

    DEFF Research Database (Denmark)

    Nordström, Maria; Johansson, Alicia; Sánchez Noguerón, E.


    We present the results from a thorough investigation of the bond strength between the photo-polymer SU-8 and Au. The data were obtained by pull-test experiments, below the glass transition temperature of the polymer. The different aspects that we investigated were:(i)the effect of using different...

  8. Using an SU-8 Photoresist Structure and Cytochrome C Thin Film Sensing Material for a Microbolometer

    Directory of Open Access Journals (Sweden)

    Guo-Dung John Su


    Full Text Available There are two critical parameters for microbolometers: the temperature coefficient of resistance (TCR of the sensing material, and the thermal conductance of the insulation structure. Cytochrome c protein, having a high TCR, is a good candidate for infrared detection. We can use SU-8 photoresist for the thermal insulation structure, given its low thermal conductance. In this study, we designed a platform structure based on a SU-8 photoresist. We fabricated an infrared sensing pixel and recorded a high TCR for this new structure. The SU-8 photoresist insulation structure was fabricated using the exposure dose method. We experimentally demonstrated high values of TCR from 22%/K to 25.7%/K, and the measured noise was 1.2 × 10–8 V2/Hz at 60 Hz. When the bias current was 2 μA, the calculated voltage responsivity was 1.16 × 105 V/W. This study presents a new kind of microbolometer based on cytochrome c protein on top of an SU-8 photoresist platform that does not require expensive vacuum deposition equipment.

  9. Using an SU-8 photoresist structure and cytochrome C thin film sensing material for a microbolometer. (United States)

    Lai, Jian-Lun; Liao, Chien-Jen; Su, Guo-Dung John


    There are two critical parameters for microbolometers: the temperature coefficient of resistance (TCR) of the sensing material, and the thermal conductance of the insulation structure. Cytochrome c protein, having a high TCR, is a good candidate for infrared detection. We can use SU-8 photoresist for the thermal insulation structure, given its low thermal conductance. In this study, we designed a platform structure based on a SU-8 photoresist. We fabricated an infrared sensing pixel and recorded a high TCR for this new structure. The SU-8 photoresist insulation structure was fabricated using the exposure dose method. We experimentally demonstrated high values of TCR from 22%/K to 25.7%/K, and the measured noise was 1.2 × 10(-8) V2/Hz at 60 Hz. When the bias current was 2 μA, the calculated voltage responsivity was 1.16 × 10(5) V/W. This study presents a new kind of microbolometer based on cytochrome c protein on top of an SU-8 photoresist platform that does not require expensive vacuum deposition equipment.

  10. Dense vertical SU-8 microneedles drawn from a heated mold with precisely controlled volume (United States)

    Xiang, Zhuolin; Wang, Hao; Kanna Murugappan, Suresh; Yen, Shih-Cheng; Pastorin, Giorgia; Lee, Chengkuo


    Drawing lithography technology has recently become a popular technique to fabricate (3D) microneedles. The conventional drawing process shows some limitations in fabricating dense, scale-up and small microneedles. In this study, we demonstrate a new drawing lithography process from a self-loading mold which is able to overcome these challenges. Different from the conventional molds which have difficult alignment and loading issues, a released SU-8 membrane is attached onto a SU-8 coated wafer to generate an innovative self-loading mold. The physically distinct SU-8 colloid in this mold successfully avoids the merging of the microneedle tips in the drawing process. Meanwhile, the same SU-8 colloid in mold can provide microneedles with uniform lengths on a large surface area. Furthermore, a low temperature drawing process with this improved technique prevents sharp tips from bending during the solidification stage. Remarkably, this new drawing lithography technology can fabricate microneedles with various lengths and they are strong enough to penetrate the outermost skin layer, namely the stratum corneum. The spacing between two adjacent microneedles is optimized to maximize the penetration rate through the skin. Histology images and drug diffusion testing demonstrate that microchannels are successfully created and the drugs can permeate the tissue under the skin. The fabricated microneedles are demonstrated to deliver insulin in vivo and lower blood glucose levels, suggesting future possible applications for minimally invasive transdermal delivery of macromolecules.

  11. Integrated SU-8 photonic gas sensors based on PANI polymer devices: Comparison between metrological parameters (United States)

    Airoudj, A.; Bêche, B.; Debarnot, D.; Gaviot, E.; Poncin-Epaillard, F.


    In this work, we have designed and developed three families of integrated photonic sensors for ammonia detection. These photonic sensors are integrated onto single-mode TE 0-TM 0 SU-8 polymer planar waveguides and based on a polyaniline (PANI) sensitive polymer material. The first family relies on the deposit of a PANI-polymethyl methacrylate (PMMA) composite sensitive layer on a given SU-8 waveguide. The second family relies on a PMMA passive layer deposited on the SU-8 waveguide before applying the PANI sensitive layer on the PMMA passive layer. The third family takes advantage of a PANI layer deposited by plasma technique directly onto the SU-8 waveguide. The working principle of such sensors is based on the optical intensity modulation induced within the single-mode waveguide owing to the interaction between the evanescent field and the sensitive layer. The sensing proprieties of these integrated photonic sensors to ammonia gas at room temperature were characterized and the comparison between these different families of photonic sensors is presented. Experimental results show that the sensor based on new plasma-PANI as sensitive layer has the better metrological parameters.

  12. Drift study of SU8 cantilevers in liquid and gaseous environments

    DEFF Research Database (Denmark)

    Tenje, Maria; Keller, Stephan Sylvest; Dohn, Søren


    We present a study of the drift, in terms of cantilever deflections without probe/target interactions, of polymeric SU8 cantilevers. The drift is measured in PBS buffer (pH 7.4) and under vacuum (1 mbar) conditions. We see that the cantilevers display a large drift in both environments. We believ...

  13. The neuroleptic activity of haloperidol increases after its solubilization in surfactant micelles. Micelles as microcontainers for drug targeting. (United States)

    Kabanov, A V; Chekhonin, V P; Alakhov VYu; Batrakova, E V; Lebedev, A S; Melik-Nubarov, N S; Arzhakov, S A; Levashov, A V; Morozov, G V; Severin, E S


    It has been suggested to use surfactant micelles as microcontainers for increasing the efficiency of neuroleptic targeting from blood flow into the brain. The neuroleptic action of haloperidol, intraperitoneally injected into mice in micellar solution of non-ionic block copolymer surfactant (pluronic P-85) in water, increased several-fold if compared with that observed for haloperidol aqueous solution. Incorporation of brain-specific antibodies into haloperidol-containing micelles resulted in additional drastic increase (more than by 2 orders of magnitude) in the drug effect.

  14. SU-8 passivation of type-II InAs/GaSb strained layer superlattice detectors (United States)

    Kim, H. S.; Plis, E.; Gautam, N.; Khoshakhlagh, A.; Myers, S.; Kutty, M. N.; Sharma, Y.; Dawson, L. R.; Krishna, S.


    We report on surface passivation studies for type-II InAs/GaSb superlattice (SL) PIN detectors designed to operate in the mid-wave infrared (MWIR) region and the long wavelength infrared (LWIR) spectrum. The two SL structures were grown by molecular beam epitaxy and processed into mesa diodes using standard lithography. A simple spin on photoresist, SU-8, was used to passivate the sample after a wet etch. Optical and electrical measurements were then undertaken on the two devices. The dark current density of a single pixel device with SU-8 passivation is reduced by four orders of magnitude and by a factor of eight compared to devices without any passivation for the MWIR and LWIR pin detectors, respectively, at 77K.

  15. Drug-polymer filled micro-containers for oral delivery loaded using supercritical CO2 aided-impregnation

    DEFF Research Database (Denmark)

    Marizza, Paolo; Keller, Stephan Sylvest; Rades, T.


    In this work we present an effective loading technique of micro-containers for oral drug delivery of a poorly water soluble drug in a solid dispersion with polymer. By combining inkjet printing and supercritical CO2 impregnation we load ketoprofen in a solid dispersion with poly(vinylpyrrolidone...

  16. Towards a compact SU-8 micro-direct methanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, J.P.; Santander, J.; Cane, C.; Sabate, N. [Instituto de Microelectronica de Barcelona, IMB-CNM (CSIC), Campus UAB, 08193 Bellaterra, Barcelona (Spain); Senn, T.; Loergen, M.; Loechel, B. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Application Centre for Microengineering, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Hernandez-Fernandez, P. [Dpto. Quimica-Fisica Aplicada, Facultad de Ciencias, Universidad Autonoma de Madrid (UAM), C/Francisco Tomas y Valiente 7, 28049 Madrid (Spain); Rojas, S. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, 28049 Madrid (Spain)


    This paper presents an all-polymer micro-direct methanol fuel cell (microDMFC) fabricated with SU-8 photoresist. The present development exploits the capability of SU-8 components to bond to each other by a hot-pressing process and obtain a compact device. The device is formed by a membrane electrode assembly (MEA) sandwiched between two current collectors. The MEA consists of a porous SU-8 membrane filled with a proton exchange polymer and covered by a thin layer of carbon-based electrodes with a low catalyst loading (1.0 mg cm{sup -2}). The current collectors consist of two metalized SU-8 plates provided with a grid of through-holes that allow delivering the reactants to the MEA by diffusion. Fuel cell characterization was performed by measuring the polarization curves under different methanol concentrations and temperatures. The components were first tested using an external casing. A maximum power density of 4.15 mW cm{sup -2} was measured with this assembly working with a 4 M methanol concentration and at a temperature of 40 C. The components were then bonded to obtain a compact micro-direct methanol fuel cell that yielded a power density of 0.65 mW cm{sup -2} under the same conditions. Despite this decrease in power density after bonding, the drastic reduction of the device dimensions resulted in an increase of more than 50 times the previous volumetric power density. The results obtained validate this novel approach to an all-polymer micro-fuel cell. (author)

  17. Performance of SU-8 Membrane Suitable for Deep X-Ray Grayscale Lithography

    Directory of Open Access Journals (Sweden)

    Harutaka Mekaru


    Full Text Available In combination with tapered-trench-etching of Si and SU-8 photoresist, a grayscale mask for deep X-ray lithography was fabricated and passed a 10-times-exposure test. The performance of the X-ray grayscale mask was evaluated using the TERAS synchrotron radiation facility at the National Institute of Advanced Industrial Science and Technology (AIST. Although the SU-8 before photo-curing has been evaluated as a negative-tone photoresist for ultraviolet (UV and X-ray lithographies, the characteristic of the SU-8 after photo-curing has not been investigated. A polymethyl methacrylate (PMMA sheet was irradiated by a synchrotron radiation through an X-ray mask, and relationships between the dose energy and exposure depth, and between the dose energy and dimensional transition, were investigated. Using such a technique, the shape of a 26-μm-high Si absorber was transformed into the shape of a PMMA microneedle with a height of 76 μm, and done with a high contrast. Although during the fabrication process of the X-ray mask a 100-μm-pattern-pitch (by design was enlarged to 120 μm. However, with an increase in an integrated dose energy this number decreased to 99 μm. These results show that the X-ray grayscale mask has many practical applications. In this paper, the author reports on the evaluation results of SU-8 when used as a membrane material for an X-ray mask.

  18. SU-8 Electrothermal Actuators: Optimization of Fabrication and Excitation for Long-Term Use

    Directory of Open Access Journals (Sweden)

    Thomas Winterstein


    Full Text Available In this paper we examine the suitability of SU-8 2000 as a construction material for electrothermal actuators and the actuator stability for long-term operation. The fabrication of SU-8 was optimized for mechanical and thermal stability. Samples with different softbake duration, exposure dose and postbake temperature were evaluated using Fourier-Transform IR-spectroscopy and dynamic-mechanical analysis. The exposure dose and postbake temperature proved to have a strong influence on the cross-linking and the glass transition temperature. A final hardbake levels the effects of the process history. A high degree of crosslinking, a low drop of the dynamic modulus over temperature (30% up to the glass transition temperature 100–140 °C were achieved for SU-8 with an exposure dose of 1500 mJ/cm², a postbake temperature of 95 °C and hardbake of 240 °C. Electrothermal actuators proved to be stable until the end of the experiment after 2400 duty cycles. Actuator deflections up to 55 μm were measured (actuator length: 4 mm for input powers up to 160 mW and a maximum operating temperature of 120 °C. Higher temperatures led to permanent deformations and failure. An offset drift of up to 20% occurs during actuation, but converges after a burn-in phase of about two hours.

  19. Design and fabricate multi channel microfluidic mold on top of glass slide using SU-8 (United States)

    Azman, N. A. N.; Rajapaksha, R. D. A. A.; Uda, M. N. A.; Hashim, U.


    Microfluidic is the study of fluid in microscale. Microfluidics provides miniaturized fluidic networks for processing and analyzing liquids in the nanoliter to milliliter range. Microfluidic device comprises of some essential segments or structure that are micromixer, microchannel and microchamber. The SU-8 mold is known as the most used technique in microfluidic fabrication due to the characteristic of very gooey polymer that can be spread over a thickness. In this study, in order to reduce the fabrication cost, the development and fabrication of SU-8 mold is replace by using a glass plate instead of silicon wafer which is used in the previous research. We designed a microfluidic chip for use with an IDE sensors to conduct multiplex detection of multiple channels. The microfluidic chip was designed to include multiplex detection for pathogen that consists of multiple channels of simultaneous results. The multi-channel microfluidic chip was designed, including the fluid outlet and inlet. A multi-channel microfluidic chip was used for pathogen detection. This paper sum up the fabrication of lab SU-8 mold using glass slide.

  20. SU-8 based microdevices to study self-induced chemotaxis in 3D microenvironments

    Directory of Open Access Journals (Sweden)

    Jose Maria Ayuso


    Full Text Available Tissues are complex three-dimensional structures in which cell behaviour is frequently guided by chemotactic signals. Although starvation and nutrient restriction induce many different chemotactic processes, the recreation of such conditions in vitro remains difficult when using standard cell culture equipment. Recently, microfluidic techniques have arisen as powerful tools to mimic such physiological conditions. In this context, microfluidic three-dimensional cell culture systems require precise control of cell/hydrogel location because samples need to be placed within a microchamber without obstruction of surrounding elements. In this article, SU-8 is studied as structural material for the fabrication of complex cell culture devices due to its good mechanical properties, low gas permeability and sensor integration capacity. In particular, this manuscript presents a SU-8 based microdevice designed to create self-induced medium starvation, based on the combination of nutrient restriction and natural cell metabolism. Results show a natural migratory response towards nutrient source, showing how cells adapt to their own microenvironment modifications. The presented results demonstrate the SU-8 potential for microdevice fabrication applied to cell culture.

  1. A study of SU-8 photoresist in deep trenches for silicon-embedded microinductors (United States)

    Laforge, Elias; Rabot, Caroline; Wang, Ningning; Pavlovic, Zoran; McCloskey, Paul; O'Mathúna, Cian


    Epoxy-based resist SU-8 is widely used in the development and fabrication of high-aspect-ratio (HAR) MEMS structures. It has proven to be a suitable photoresist combining thick layer coating and good adhesion on silicon substrates as well as possessing good mechanical and chemical stability. However, the trend towards minia- turization and increasing packaging density has pushed the demand for challenging micro-machining processes. As an example, a novel design of a MEMS microinductor requires a dielectric permanent layer coated in deep silicon trenches in order to insulate copper windings from the magnetic material deposited in these trenches. This requires the development of a photolithography process which enables the coating of a void-free layer filling the trenches. In this paper, the use of thick SU-8 photoresist for filling deep silicon trenches is investigated. Different SU-8 formulations are analyzed, processed and results are compared. As a result, an optimized process is developed to achieve void-free filled trenches and a uniform planar layer above them, with near vertical sidewall patterns.

  2. SU-8 as Hydrophobic and Dielectric Thin Film in Electrowetting-on-Dielectric Based Microfluidics Device

    Directory of Open Access Journals (Sweden)

    Vijay Kumar


    Full Text Available Electrowetting-on-dielectric (EWOD based droplet actuation in microfluidic chip is designed and fabricated. EWOD is used as on-chip micro-pumping scheme for moving fluid digitally in Lab-on-a-chip devices. For enabling this scheme, stacked deposition of thin dielectric and hydrophobic layer in that order between microchannel and electrodes is done. The present paper investigates the potential use of SU-8 as hydrophobic layer in conjunction of acting as dielectric in the device. The objective for the investigation is to lower the cost and a thin simplification in fabrication process of EWOD-based devices. We have done design and optimization of dimensions of electrode array including gap between arrays for EWOD micropump. Design and optimization are carried out in CoventorWare. The designing is followed by fabrication of device and analysis for droplet motion. The fabrication of the device includes array of electrodes over the silicon surface and embedding them in hydrophobic SU-8 layer. Water droplet movement in the order of microliter of spherical shape is demonstrated. It has been shown that an SU-8 microchannel in the current design allows microfluidic flow at tens of voltages comparable with costlier and more complicated to fabricate designs reported in the literature.

  3. PMMA to SU-8 Bonding for Polymer Based Lab-on -a-chip Systems with Integrated Optics

    DEFF Research Database (Denmark)

    Clausen, Bjarne


    An adhesive bonding technique for wafer-level sealing of SU-8 based lab-on-a-chip microsystems with integrated optical components is presented. Microfluidic channels and optical components, e.g. waveguides, are fabricated in cross-linked SU-8 and sealed with a Pyrex glass substrate by means...

  4. PMMA to SU-8 bonding for polymer based lab-on-a-chip systems with integrated optics

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Nielsen, Theodor; Clausen, Bjarne Hans


    We present an adhesive bonding technique developed for SU-8 based "lab-on-a-chip"- systems with integrated optical components. Microfluidic channels and optical components (e.g. wave-guides) are defined in SU-8 photoresist on a Pyrex glass substrate. The microfluidic channels are sealed by a second...

  5. SU-8 cantilevers for bio/chemical sensing; Fabrication, characterisation and development of novel read-out methods

    DEFF Research Database (Denmark)

    Nordström, M.; Keller, Stephan Urs; Lillemose, Michael


    Here, we present the activities within our research group over the last five years with cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interesting polymer for fabrication of cantilevers for bio/chemical sensing due to its simple processing and low Young's modulus. We show...

  6. Simulation and experimental validation of a SU-8 based PCR thermocycler chip with integrated heaters and temperature sensor

    DEFF Research Database (Denmark)

    El-Ali, Jamil; Perch-Nielsen, Ivan R.; Poulsen, Claus Riber


    C/s, respectively, the performance of the chip is comparable with the best silicon micromachined PCR chips presented in the literature. The SU-8 chamber surface was found to be PCR compatible by amplification of yeast gene ribosomal protein S3 and Campylobacter gene cadF. The PCR compatibility of the chamber......We present a SU-8 based polymerase chain reaction (PCR) chip with integrated platinum thin film heaters and temperature sensor. The device is fabricated in SU-8 on a glass substrate. The use of SU-8 provides a simple microfabrication process for the PCR chamber, controllable surface properties...... and can allow on chip integration to other SU-8 based functional elements. Finite element modeling (FEM) and experiments show that the temperature distribution in the PCR chamber is homogeneous and that the chip is capable of fast thermal cycling. With heating and cooling rates of up to 50 and 30 degrees...

  7. Fabrication of thin SU-8 cantilevers: initial bending, release and time stability

    DEFF Research Database (Denmark)

    Keller, Stephan Urs; Haefliger, D.; Boisen, Anja


    development of the thin SU-8 film resulted in reduced cantilever bending due to removal of residual stress gradients. Further, improved time-stability of the devices was achieved due to the enhanced cross-linking of the polymer. A post-exposure bake at a temperature T-PEB = 50 degrees C followed by a hard...... bake at T-HB = 90 degrees C proved to be optimal to ensure low cantilever bending and low rotational deformation due to excellent device release and low change of these properties with time. With the optimized process, the reproducible fabrication of arrays with 2 mu m thick cantilevers with a length...

  8. Development of vertical SU-8 microneedles for transdermal drug delivery by double drawing lithography technology. (United States)

    Xiang, Zhuolin; Wang, Hao; Pant, Aakanksha; Pastorin, Giorgia; Lee, Chengkuo


    Polymer-based microneedles have drawn much attention in transdermal drug delivery resulting from their flexibility and biocompatibility. Traditional fabrication approaches are usually time-consuming and expensive. In this study, we developed a new double drawing lithography technology to make biocompatible SU-8 microneedles for transdermal drug delivery applications. These microneedles are strong enough to stand force from both vertical direction and planar direction during penetration. They can be used to penetrate into the skin easily and deliver drugs to the tissues under it. By controlling the delivery speed lower than 2 μl/min per single microneedle, the delivery rate can be as high as 71%.

  9. Micro-particle filter made in SU-8 for biomedical applications

    DEFF Research Database (Denmark)

    Noeth, Nadine-Nicole; Keller, Stephan Urs; Fetz, Stefanie


    We have integrated a micro-particle filter in a polymer cantilever to filter micro-particles from a fluid while simultaneously measuring the amount of filtered particles. In a 3,8 mum thick SU-8 cantilever a filter was integrated with pore sizes between 3 and 30 mum. The chip was inserted...... in a microfluidic system and water with differently sized polystyrene beads was pumped through the filter. Particles which are larger than the pore sizes, cannot pass the filter and will increase the flow resistance of the cantilever. With more and more captured particles the cantilever starts to deflect, which can...

  10. A SU-8/PDMS hybrid microfluidic device with integrated optical fibers for online monitoring of lactate. (United States)

    Wu, Min-Hsien; Cai, Haoyuan; Xu, Xia; Urban, Jill P G; Cui, Zhan-Feng; Cui, Zheng


    A microfluidic device with integrated optical fibres was developed for online monitoring of lactate. The device consists of a SU-8 waveguide, microfluidic channels and grooves for the insertion of optic fibres. It was fabricated by one-step photolithography of SU-8 polymer resist. Different channel widths (50-300 microm) were tested in terms of detection sensitivity. A wide range of flow rates were applied to investigate the influence of flow rate on signal fluctuations. The separation between optical fibre sensor and microfluidic channel and the width of fluidic channel have been optimized to maximize the detection sensitivity. It was revealed that 250 microm of channel width is the optimum light path length for a compromise between detection sensitivity and interference of ambient light. The independence of detection signals on flow rates was demonstrated within the range of flow rate (0.5-5 ml/hr) tested. Compared with conventional lactate detection, the device is proved to have high accuracy, relatively low limit of detection (50 mg/L) and reasonably fast response time (100 sec). The fabrication of device is simple and low cost. The present work has provided some fundamental data for further system optimization to meet specific detection requirements.

  11. Inkjet Printing of High Aspect Ratio Superparamagnetic SU-8 Microstructures with Preferential Magnetic Directions

    Directory of Open Access Journals (Sweden)

    Loïc Jacot-Descombes


    Full Text Available Structuring SU-8 based superparamagnetic polymer composite (SPMPC containing Fe3O4 nanoparticles by photolithography is limited in thickness due to light absorption by the nanoparticles. Hence, obtaining thicker structures requires alternative processing techniques. This paper presents a method based on inkjet printing and thermal curing for the fabrication of much thicker hemispherical microstructures of SPMPC. The microstructures are fabricated by inkjet printing the nanoparticle-doped SU-8 onto flat substrates functionalized to reduce the surface energy and thus the wetting. The thickness and the aspect ratio of the printed structures are further increased by printing the composite onto substrates with confinement pedestals. Fully crosslinked microstructures with a thickness up to 88.8 μm and edge angle of 112° ± 4° are obtained. Manipulation of the microstructures by an external field is enabled by creating lines of densely aggregated nanoparticles inside the composite. To this end, the printed microstructures are placed within an external magnetic field directly before crosslinking inducing the aggregation of dense Fe3O4 nanoparticle lines with in-plane and out-of-plane directions.

  12. Development of vertical SU-8 microtubes integrated with dissolvable tips for transdermal drug delivery. (United States)

    Xiang, Zhuolin; Wang, Hao; Pant, Aakanksha; Pastorin, Giorgia; Lee, Chengkuo


    Polymer-based microneedles have drawn much attention in the transdermal drug delivery resulting from their flexibility and biocompatibility. Traditional fabrication approach deploys various kinds of molds to create sharp tips at the end of needles for the penetration purpose. This approach is usually time-consuming and expensive. In this study, we developed an innovative fabrication process to make biocompatible SU-8 microtubes integrated with biodissolvable maltose tips as novel microneedles for the transdermal drug delivery applications. These microneedles can easily penetrate the skin's outer barrier represented by the stratum corneum (SC) layer. The drug delivery device of mironeedles array with 1000 μm spacing between adjacent microneedles is proven to be able to penetrate porcine cadaver skins successfully. The maximum loading force on the individual microneedle can be as large as 7.36 ± 0.48N. After 9 min of the penetration, all the maltose tips are dissolved in the tissue. Drugs can be further delivered via these open biocompatible SU-8 microtubes in a continuous flow manner. The permeation patterns caused by the solution containing Rhodamine 110 at different depths from skin surface were characterized via a confocal microscope. It shows successful implementation of the microneedle function for fabricated devices.

  13. Dielectric properties of ligand-modified gold nanoparticle/SU-8 photopolymer based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Toor, Anju, E-mail: [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); So, Hongyun, E-mail: [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Pisano, Albert P. [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093 (United States)


    Highlights: • Ligand-modified gold NP/SU-8 nanocomposites were synthesized and demonstrated. • Particle agglomeration and dispersion were characterized with different NPs concentration. • Nanocomposites showed higher average dielectric permittivity compared to SU-8 only. • Relatively lower dielectric loss (average 0.09 at 1 kHz) was achieved with 10 % w/w NPs. - Abstract: This article reports the enhanced dielectric properties of a photodefinable polymer nanocomposite material containing sub–10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of the dielectric permittivity and loss tangent on the particle concentration, and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

  14. A two-step sealing-and-reinforcement SU8 bonding paradigm for the fabrication of shallow microchannels (United States)

    Mehboudi, Aryan; Yeom, Junghoon


    Adhesive bonding is a key technique to create microfluidic devices when two separate substrates are used to form microchannels. Among many adhesives explored in microchannel fabrication, SU8 has been widely used as an adhesive layer for sealing the microchannel sidewalls. The majority of the available SU8-based bonding methods, however, suffer from the difficulties associated with sealing of two important types of the microchannel architecture: (1) shallow microchannels with small patterns on a large area, and (2) microchannels with ultra-low aspect ratios (e.g. 6 mm in width and 2~μ m in height). In this paper, a new bonding paradigm based upon the low-temperature and low-pressure SU8 bonding, consisting of two steps of sealing using a thin-SU8-coated PET film and bonding reinforcement using a SU8-coated glass slide, is proposed to resolve the aforementioned difficulties. Since it does not need complicated instruments such as a wafer bonding machine and a lamination device, the developed bonding paradigm is convenient and economical. We successfully demonstrate the compatibility of the proposed bonding paradigm with the two microchannel fabrication approaches based on the glass wet etching and the SU8 photo-lithography, where small microchannels with the innermost surfaces fully made of SU8 are obtained. A theoretical model is employed to better investigate the flow characteristics and the structural behavior of the microchannel including the PET film deformation, strain and von Mises stress distributions, bonding strength, etc. Moreover, we demonstrate the fabrication of the multi-height deep–shallow microchannel sidewalls and their sealing using the SU8-coated PET film. Finally, as a proof-of-concept device, a microfluidic filter consisting of the double-height deep–shallow microchannel is fabricated for separation of 3 µm and 10 µm particles.

  15. Applications of SU-8 in the development of a Single Ion Hit Facility

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga-Marrero, N. [Division of Nuclear Physics, Department of Physics, Lund University, Professorsgatan 1, Box 118, SE-22100 Lund (Sweden)], E-mail:; Astromskas, G. [Division of Solid State Physics, Department of Physics, Lund University, Professorsgatan 1, Box 118, SE-22100 Lund (Sweden); Olsson, M.G. [Department of Infection Medicine, Lund University, Soelvegatan 19, B14, SE-22184 Lund (Sweden); Elfman, M.; Kristiansson, P.; Nilsson, E.J.C.; Nilsson, C.; Pallon, J. [Division of Nuclear Physics, Department of Physics, Lund University, Professorsgatan 1, Box 118, SE-22100 Lund (Sweden)


    The Lund Nuclear Microprobe (LNM) has been adapted to be used as a Single Ion Hit Facility (SIHF) for proton cell irradiation experiments at low dose. In order to test the capabilities of the system, Ni dot arrays and artificial cells have been fabricated with the photopolymer SU-8 and common lithographic techniques. The primary purpose of the Ni dot arrays was to determine the targeting accuracy of the beam in vacuum and in air. Additionally, this sample was employed to evaluate the system performance during cell target irradiation experiments. The Ni dot arrays were also used for beam characterization. The artificial cells were originally fabricated to test the software for cell recognition and localization, developed and implemented at the LNM. However, this sample became very functional to make small adjustments at the irradiation chamber for cell irradiation experiments. A description of the samples, fabrication procedure and applications are presented in this paper.

  16. A superhydrophobic chip based on SU-8 photoresist pillars suspended on a silicon nitride membrane

    KAUST Repository

    Marinaro, Giovanni


    We developed a new generation of superhydrophobic chips optimized for probing ultrasmall sample quantities by X-ray scattering and fluorescence techniques. The chips are based on thin Si3N4 membranes with a tailored pattern of SU-8 photoresist pillars. Indeed, aqueous solution droplets can be evaporated and concentrated at predefined positions using a non-periodic pillar pattern. We demonstrated quantitatively the deposition and aggregation of gold glyconanoparticles from the evaporation of a nanomolar droplet in a small spot by raster X-ray nanofluorescence. Further, raster nanocrystallography of biological objects such as rod-like tobacco mosaic virus nanoparticles reveals crystalline macro-domain formation composed of highly oriented nanorods. © 2014 the Partner Organisations.

  17. Simulation of a low frequency Z-axis SU-8 accelerometer in coventorware and MEMS+

    KAUST Repository

    Carreno, Armando Arpys Arevalo


    This paper presents the simulation of a z-axis SU-8 capacitive accelerometer. The study consists of a modal analysis of the modeled accelerometer, a study relating capacitance to acceleration, capacitance to deflection, an effective spring constant calculation, and a comparison of results achieved using CoventorWare® ANALYZER™ and MEMS+®. A fabricated energy harvester design from [1] was used for modeling and simulation in this study, with a four spring attachment of a 650μm×650μm; ×110μm proof mass of 4.542×10-8 kg. At rest, the spacing between electrodes is 4μm along the z-axis, and at 1.5g acceleration, there is 1.9μm spacing between electrodes, at which point pull in occurs for a 1V voltage. © 2013 IEEE.

  18. Deep proton writing of high aspect ratio SU-8 micro-pillars on glass

    Energy Technology Data Exchange (ETDEWEB)

    Ebraert, Evert, E-mail:; Rwamucyo, Ben; Thienpont, Hugo; Van Erps, Jürgen


    Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer micro-structures. We use SU-8, a negative resist, spincoated in a layer up to 720 μm-thick in a single step on borosilicate glass, for irradiation with a collimated 12 MeV energy proton beam. Micro-pillars with a slightly conical profile are irradiated in the SU-8 layer. We determine the optimal proton fluence to be 1.02 × 10{sup 4} μm{sup −2}, with which we are able to repeatably achieve micro-pillars with a top-diameter of 138 ± 1 μm and a bottom-diameter of 151 ± 3 μm. The smallest fabricated pillars have a top-diameter of 57 ± 5 μm. We achieved a root-mean-square sidewall surface roughness between 19 nm and 35 nm for the fabricated micro-pillars, measured over an area of 5 × 63.7 μm. We briefly discuss initial testing of two potential applications of the fabricated micro-pillars. Using ∼100 μm-diameter pillars as waveguides for gigascale integration optical interconnect applications, has shown a 4.7 dB improvement in optical multimode fiber-to-fiber coupling as compared to the case where an air–gap is present between the fibers at the telecom wavelength of 1550 nm. The ∼140 μm-diameter pillars were used for mold fabrication with silicone casting. The resulting mold can be used for hydrogel casting, to obtain hydrogel replicas mimicking human tissue for in vitro bio-chemical applications.

  19. SU-8 Based MEMS Process with Two Metal Layers using α-Si as a Sacrificial Material

    KAUST Repository

    Ramadan, Khaled S.


    Polymer based microelectromechanical systems (MEMS) micromachining is finding more interest in research and applications. This is due to its low cost and less time processing compared with silicon MEMS. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic devices. In addition to being processed with low cost, it is a biocompatible material with good mechanical properties. Also, amorphous silicon (α-Si) has found use as a sacrificial layer in silicon MEMS applications. α-Si can be deposited at large thicknesses for MEMS applications and also can be released in a dry method using XeF2 which can solve stiction problems related to MEMS applications. In this thesis, an SU-8 MEMS process is developed using amorphous silicon (α-Si) as a sacrificial layer. Electrostatic actuation and sensing is used in many MEMS applications. SU-8 is a dielectric material which limits its direct use in electrostatic actuation. This thesis provides a MEMS process with two conductive metal electrodes that can be used for out-of-plane electrostatic applications like MEMS switches and variable capacitors. The process provides the fabrication of dimples that can be conductive or non-conductive to facilitate more flexibility for MEMS designers. This SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were tuned for two sets of thicknesses which are thin (5-10μm) and thick (130μm). Chevron bent-beam structures and different suspended beams (cantilevers and bridges) were fabricated to characterize the SU-8 process through extracting the density, Young’s Modulus and the Coefficient of Thermal Expansion (CTE) of SU-8. Also, the process was tested and used as an educational tool through which different MEMS structures were fabricated including MEMS switches, variable capacitors and thermal actuators.

  20. Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

    KAUST Repository

    Ramadan, Khaled S.


    This work presents an SU-8 surface micromachining process using amorphous silicon as a sacrificial material, which also incorporates two metal layers for electrical excitation. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic applications due to its mechanical properties, biocompatibility and low cost. Amorphous silicon is used as a sacrificial layer in MEMS applications because it can be deposited in large thicknesses, and can be released in a dry method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using ;-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow out-of-plane electrostatic actuation for applications like MEMS switches and variable capacitors. In order to facilitate more flexibility for MEMS designers, the process can fabricate dimples that can be conductive or nonconductive. Additionally, this SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were optimized for two sets of thicknesses: thin (5-10 m) and thick (130 m). The process was tested fabricating MEMS switches, capacitors and thermal actuators. © 2013 IOP Publishing Ltd.

  1. A highly integrated vertical SU8 valve for stepwise in-series reactions (United States)

    Calvo, V.; Ezkerra, A.; Elizalde, J.; Fernández, L. J.; Berganzo, J.; Mayora, K.; Ruano-López, J. M.


    Stepwise performance of reactions demands highly integrated microfluidic control. The vertical valve presented in this work allows performing reactions in cascade with reduced control requirements, by controlling the rupture of an SU8 wall that separates a chamber from an adjacent evacuation channel. Owing to its vertical construction, the valve can be readily integrated into any geometry with a low increase in footprint. Two valve approaches are presented, which differ in the location of the rupture region, the breaking pressures and the size of the fluidic path open. Breaking the wall about its upper end has proven to be more limited in terms of geometry and resulting gap size, whereas breaking the wall about its root opens a wider fluidic path that allows smooth filling of downstream chambers. Following these conclusions, a sequence of two reactions has been demonstrated, using a wall-valve-regulated double-chamber device. The chosen protocol, DNA concentration, elution and transport, has been successfully accomplished, as evidenced by positive on-chip polymerase chain reaction in a second double-chamber device.

  2. MEMS flexible artificial basilar membrane fabricated from piezoelectric aluminum nitride on an SU-8 substrate (United States)

    Jang, Jongmoon; Jang, Jeong Hun; Choi, Hongsoo


    In this paper, we present a flexible artificial basilar membrane (FABM) that mimics the passive mechanical frequency selectivity of the basilar membrane. The FABM is composed of a cantilever array made of piezoelectric aluminum nitride (AlN) on an SU-8 substrate. We analyzed the orientations of the AlN crystals using scanning electron microscopy and x-ray diffraction. The AIN crystals are oriented in the c-axis (0 0 2) plane and effective piezoelectric coefficient was measured as 3.52 pm V-1. To characterize the frequency selectivity of the FABM, mechanical displacements were measured using a scanning laser Doppler vibrometer. When electrical and acoustic stimuli were applied, the measured resonance frequencies were in the ranges of 663.0-2369 Hz and 659.4-2375 Hz, respectively. These results demonstrate that the mechanical frequency selectivity of this piezoelectric FABM is close to the human communication frequency range (300-3000 Hz), which is a vital feature of potential auditory prostheses.

  3. Study of functional viability of SU-8-based microneedles for neural applications (United States)

    Fernández, Luis J.; Altuna, Ane; Tijero, Maria; Gabriel, Gemma; Villa, Rosa; Rodríguez, Manuel J.; Batlle, Montse; Vilares, Roman; Berganzo, Javier; Blanco, F. J.


    This paper presents the design, fabrication, packaging and first test results of SU-8-based microneedles for neural applications. By the use of photolithography, sputtering and bonding techniques, polymer needles with integrated microchannels and electrodes have been successfully fabricated. The use of photolithography for the patterning of the fluidic channel integrated in the needle allows the design of multiple outlet ports at the needle tip, minimizing the possibility of being blocked by the tissue. Furthermore, the flexibility of the polymer reduces the risk of fracture and tissue damage once the needle is inserted, while it is still rigid enough to allow a perfect insertion into the neural tissue. Fluidic and electric characterization of the microneedles has shown their viability for drug delivery and monitoring in neural applications. First drug delivery tests in ex vivo tissue demonstrated the functional viability of the needle to deliver drugs to precise points. Furthermore, in vivo experiments have demonstrated lower associated damages during insertion than those by stereotaxic standard needles.

  4. Arrayed SU-8 polymer thermal actuators with inherent real-time feedback for actively modifying MEMS’ substrate warpage (United States)

    Wang, Xinghua; Xiao, Dingbang; Chen, Zhihua; Wu, Xuezhong


    This paper describes the design, fabrication and characterization of a batch-fabricated micro-thermal actuators array with inherent real-time self-feedback, which can be used to actively modify micro-electro-mechanical systems’ (MEMS’) substrate warpage. Arrayed polymer thermal actuators utilize SU-8 polymer (a thick negative photoresist) as a functional material with integrated Ti/Al film-heaters as a microscale heat source. The electro-thermo-mechanical response of a micro-fabricated actuator was measured. The resistance of the Al/Ti film resistor varies obviously with ambient temperature, which can be used as inherent feedback for observing real-time displacement of activated SU-8 bumps (0.43 μm Ω-1). Due to the high thermal expansion coefficient, SU-8 bumps tend to have relatively large deflection at low driving voltage and are very easily integrated with MEMS devices. Experimental results indicated that the proposed SU-8 polymer thermal actuators (array) are able to achieve accurate rectification of MEMS’ substrate warpage, which might find potential applications for solving stress-induced problems in MEMS.

  5. Cloning SU8 silicon masters using epoxy resins to increase feature replicability and production for cell culture devices (United States)

    Kamande, J. W.; Wang, Y.; Taylor, A. M.


    In recent years, there has been a dramatic increase in the use of poly(dimethylsiloxane) (PDMS) devices for cell-based studies. Commonly, the negative tone photoresist, SU8, is used to pattern features onto silicon wafers to create masters (SU8-Si) for PDMS replica molding. However, the complexity in the fabrication process, low feature reproducibility (master-to-master variability), silane toxicity, and short life span of these masters have been deterrents for using SU8-Si masters for the production of cell culture based PDMS microfluidic devices. While other techniques have demonstrated the ability to generate multiple devices from a single master, they often do not match the high feature resolution (∼0.1 μm) and low surface roughness that soft lithography masters offer. In this work, we developed a method to fabricate epoxy-based masters that allows for the replication of features with high fidelity directly from SU8-Si masters via their PDMS replicas. By this method, we show that we could obtain many epoxy based masters with equivalent features to a single SU8-Si master with a low feature variance of 1.54%. Favorable feature transfer resolutions were also obtained by using an appropriate Tg epoxy based system to ensure minimal shrinkage of features ranging in size from ∼100 μm to epoxy masters with Cr/Au lead to effective demolding and yield PDMS chambers that are suitable for long-term culturing of sensitive primary hippocampal neurons. Finally, we incorporated pillars within the Au-epoxy masters to eliminate the process of punching media reservoirs and thereby reducing substantial artefacts and wastage. PMID:26180572

  6. Cloning SU8 silicon masters using epoxy resins to increase feature replicability and production for cell culture devices. (United States)

    Kamande, J W; Wang, Y; Taylor, A M


    In recent years, there has been a dramatic increase in the use of poly(dimethylsiloxane) (PDMS) devices for cell-based studies. Commonly, the negative tone photoresist, SU8, is used to pattern features onto silicon wafers to create masters (SU8-Si) for PDMS replica molding. However, the complexity in the fabrication process, low feature reproducibility (master-to-master variability), silane toxicity, and short life span of these masters have been deterrents for using SU8-Si masters for the production of cell culture based PDMS microfluidic devices. While other techniques have demonstrated the ability to generate multiple devices from a single master, they often do not match the high feature resolution (∼0.1 μm) and low surface roughness that soft lithography masters offer. In this work, we developed a method to fabricate epoxy-based masters that allows for the replication of features with high fidelity directly from SU8-Si masters via their PDMS replicas. By this method, we show that we could obtain many epoxy based masters with equivalent features to a single SU8-Si master with a low feature variance of 1.54%. Favorable feature transfer resolutions were also obtained by using an appropriate Tg epoxy based system to ensure minimal shrinkage of features ranging in size from ∼100 μm to epoxy masters with Cr/Au lead to effective demolding and yield PDMS chambers that are suitable for long-term culturing of sensitive primary hippocampal neurons. Finally, we incorporated pillars within the Au-epoxy masters to eliminate the process of punching media reservoirs and thereby reducing substantial artefacts and wastage.

  7. Novel fabrication process for 3D meander-shaped microcoils in SU-8 dielectric and their application to linear micromotors (United States)

    Seidemann, Volker; Buettgenbach, Stephanus


    This paper reports on an optimized fabrication process for three dimensional coil structures such as meander or helical coils wound around in plane magnetic structures. The process consists of UV depth lithography employing AZ4562 and SU8 photo resists and electroplating of copper and nickel-iron. Furthermore SU8 is used as the embedding dielectric due to its excellent planarization properties and high structural aspect ratio. Special emphasis was laid on the decrease of via interconnect resistance by electroplating the vias and upper conductors in a single step thus avoiding a large number of resistive interfaces. This was achieved by sacrificial wiring and structured seed layers. The developed technology is applied to a variable reluctance micro motor with a novel design that avoids high friction. The presented concept makes use of a stator traveler configuration generating complementary attraction forces. The technology and design concept is presented and first results are demonstrated.

  8. Fabrication of three-dimensional SU-8 microchannels by proton beam writing for microfluidics applications: Fluid flow characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Shehri, S., E-mail:; Palitsin, V.; Webb, R.P.; Grime, G.W.


    The proton beam writing (PBW) technique was used to fabricate microfluidic structures in SU-8 resist. A network of the buried channels was fabricated as part of a project to develop functional microfluidic device for neuronal studies and self-powered microfluidics. Protons with energies between 2.5 MeV and 0.75 MeV were used to fabricate the buried channels with a minimum feature size of around 1 μm and depths of 40–55 μm. Roughness of channels sidewalls was around 2.5 nm rms. Exposure regime and examples of functional networks fabricated using PBW are described. COMSOL Multiphysics® software was used to model the flow characteristics of fluid in the SU-8 microchannels structured by PBW. The results obtained using PBW are compared with the structures fabricated by UV-lithography.

  9. Comparative study between the results of effective index based matrix method and characterization of fabricated SU-8 waveguide (United States)

    Samanta, Swagata; Dey, Pradip Kumar; Banerji, Pallab; Ganguly, Pranabendu


    A study regarding the validity of effective-index based matrix method (EIMM) for the fabricated SU-8 channel waveguides is reported. The design method is extremely fast compared to other existing numerical techniques, such as, BPM and FDTD. In EIMM, the effective index method was applied in depth direction of the waveguide and the resulted lateral index profile was analyzed by a transfer matrix method. By EIMM one can compute the guided mode propagation constants and mode profiles for each mode for any dimensions of the waveguides. The technique may also be used to design single mode waveguide. SU-8 waveguide fabrication was carried out by continuous-wave direct laser writing process at 375 nm wavelength. The measured propagation losses of these wire waveguides having air and PDMS as superstrates were 0.51 dB/mm and 0.3 dB/mm respectively. The number of guided modes, obtained theoretically as well as experimentally, for air-cladded waveguide was much more than that of PDMS-cladded waveguide. We were able to excite the isolated fundamental mode for the later by precise fiber positioning, and mode image was recorded. The mode profiles, mode indices, and refractive index profiles were extracted from this mode image of the fundamental mode which matched remarkably well with the theoretical predictions.

  10. A high aspect ratio SU-8 fabrication technique for hollow microneedles for transdermal drug delivery and blood extraction (United States)

    Chaudhri, Buddhadev Paul; Ceyssens, Frederik; De Moor, Piet; Van Hoof, Chris; Puers, Robert


    Protein drugs, e.g. hormonal drugs, cannot be delivered orally to a patient as they get digested in the gastro-intestinal (GI) tract. Thus, it is imperative that these kinds of drugs are delivered transdermally through the skin. To provide for real-time feedback as well as to test independently for various substances in the blood, we also need a blood sampling system. Microneedles can perform both these functions. Further, microneedles made of silicon or metal have the risk of breaking inside the skin thereby leading to complications. SU-8, being approved of as being biocompatible by the Food and Drug Agency (FDA) of the United States, is an attractive alternative because firstly it is a polymer material, thereby reducing the chances of breakages inside the skin, and secondly it is a negative photoresist, thereby leading to ease of fabrication. Thus, here we present very tall (around 1600 µm) SU-8 polymer-based hollow microneedles fabricated by a simple and repeatable process, which are a very good candidate for transdermal drug delivery as well as blood extraction. The paper elaborates on the details that allow the fabrication of such extreme aspect ratios (>100).

  11. Screen Printing of SU-8 Layers for Microstructure Fabrication / Ar Sietspiedi Uzklātu SU-8 Pārklājumi Mikro-Struktūru Izgatavošanai (United States)

    Klavins, J.; Mozolevskis, G.; Ozols A., A.; Nitiss, E.; Rutkis, M.


    We report on a screen printing fabrication process for large-area SU-8 layers utilised for the preparation of microstructures in display devices such as microelectronic, electrowetting or bistable devices. The screen printing method has been selected for its effectiveness and simplicity over traditionally used spin-coating ones. Layers and microstructures produced thereof have shown proper homogeneity. Relationships between screen parameters to coating thickness have been established. Coating on an ITO (indium tin oxide) hydrophobic surface is possible when surface has been treated by UV/Ozone to increase its aqueous ability. To this end, the hydrophilic microstructure grids have been successfully built on a hydrophobic layer by screen printing and traditional lithography processes. Compared to conventional spin-coating methods, the screen printing method offers the advantages of simple, cheap and fast fabrication, and is especially suitable for large-area display fabrication Rakstā aprakstīta sietspiedes metode liela izmēra SU-8 pārklājumu iegūšanai, lai izgatavotu mikrostruktūras mikroelektronikai, elektroslapināšanas un bistabilajiem ekrāniem. Sietspiede ir efektīvāka un vienkāršāka metode nekā tradicionāli izmantotā spin-coating metode. Šādiem pārklājumuiem un mikrostruktūrām ir pietiekoša homogenitāte. Tika atrasta sakarība starp sietu parametriem un pārklājumu biezumu. Pārklājumus var uzklāt uz hidrofobiskās ITO (indija alvas oksīds) virsmas, ja tā tiek apstrādāta ar UV/Ozonu, jo tas palielina ūdens slapināšanas īpašības. Tika izgatavoti hidrofīliskas mikrostruktūras režģi uz hidrofobiskas pamatnes ar sietspiedi un tradicionālo SU-8 litogrāfijas metodi. Salīdzinājumā ar tradicionālo spin-coating metodi, sietspiede ir vienkārša, lēta un ātra un ir labi piemērota liela izmēra ekrānu izgatavošanai.


    Miller, Eric; Ellis, Daniel; Charles, Duran; McKenzie, Jason


    A materials fabrication study of a photodiode array for possible application of retina prosthesis was undertaken. A test device was fabricated using a glassy carbon electrode patterned with SU-8 photoresist. In the openings, p-type polypyrrole was first electrodeposited using 1-butyl-1-methylpyridinium bis(trifluoromethylsulfonyl)imide ionic liquid. The polypyrrole was self-doped with imide ion at ~1.5 mole %, was verified as p-type, and had a resistivity of ~20 Ωcm. N-type Silicon was then electrodeposited over this layer using silicon tetrachloride / phosphorus trichloride in acetonitrile and passivated in a second electrodeposition using trimethylchlorosilane. Electron microscopy revealed the successful electrodeposition of silicon over patterned polypyrrole. Rudimentary photodiode behavior was observed. The passivation improved but did not completely protect the electrodeposited silicon from oxidation by air.

  13. New Formation Technology of Plasma Display Panel Barrier-Rib Structure Using Silicone Rubber Mold Transferred from SU-8 Master Structure (United States)

    Son, Seung-Hyun; Park, Yong-Suk; Choi, Sie-Young


    A new formation technology for a plasma display panel (PDP) barrier-rib structure is presented to realize a barrier rib with a high aspect ratio and reduce the manufacturing cost. In this study, we used an SU-8 50 photoresist, which is sensitive to UV irradiation, instead of polymethylmethacrylate (PMMA) which is sensitive to X-ray irradiation, so that the silicone rubber mold could be applicable to a large-area PDP. The first step is to produce an SU-8 master structure using amorphous silicon as an adhesion layer between a glass substrate and SU-8 photoresist. Second, a precise soft mold is manufactured for mass replication of the PDP barrier-rib construction, by molding liquid silicone rubber onto the glass substrate with lithographically defined SU-8 master structures. Third, a PDP barrier-rib structure is formed using the pattern-transferring process with a reusable silicone rubber mold. This is a very simple and inexpensive process consisting with printing of barrier-rib paste, drying, pattern-transferring, and sintering. The pattern-transferring process with a soft mold also demonstrates that the disadvantages of the conventional mold pressing process with a hard mold can be overcome. Consequently, by using the pattern-transferring process with the silicone rubber mold transferred from the SU-8 master structure, the desired barrier-rib shapes can be realized with a high aspect ratio and various dimensions.

  14. Reduction of surface leakage current in InAs/GaSb strained layer long wavelength superlattice detectors using SU-8 passivation (United States)

    Kim, H. S.; Plis, E.; Gautam, N.; Myers, S.; Sharma, Y.; Dawson, L. R.; Krishna, S.


    We report on SU-8 passivation for reducing surface leakage current in type-II InAs/GaSb strained layer superlattice detectors (λ100% cut-off˜12 μm). The electrical behavior of SU-8 passivated and unpassivated devices was compared for devices with variable mesa sizes. Dark current was reduced by more than one order of magnitude for the small area (50 μm×50 μm) passivated diode at 77 K. The surface resistivity, the responsivity and specific detectivity were measured for SU-8 passivated devices and are equal to 204 Ω cm, 0.58 A/W and 3.49×109 Jones, respectively (77 K).

  15. Performance improvement of InAs/GaSb strained layer superlattice detectors by reducing surface leakage currents with SU-8 passivation (United States)

    Kim, H. S.; Plis, E.; Khoshakhlagh, A.; Myers, S.; Gautam, N.; Sharma, Y. D.; Dawson, L. R.; Krishna, S.; Lee, S. J.; Noh, S. K.


    We report on SU-8 passivation for performance improvement of type-II InAs/GaSb strained layer superlattice detectors (λcut-off˜4.6 μm). Optical and electrical behavior of SU-8 passivated and unpassivated devices was compared. The dark current density was improved by four orders of magnitude for passivated single diodes at 77 K. The zero bias responsivity and detectivity at 77 K was equal to 0.9 A/W and 3.5×1012 Jones for SU-8 passivated single pixel diodes. FPA size diodes (24×24 μm2) were also fabricated and they showed responsivity and detectivity of 1.3 A/W and 3.5×1012 Jones, respectively at 77 K.

  16. Design, numerical simulation and experimental investigation of an SU-8 microgripper based on the cascaded V-shaped electrothermal actuators (United States)

    Voicu, Rodica-Cristina


    This paper presents the numerical simulation results and the experimental investigations of a polymeric microgripper designed using the cascaded V-shaped electrothermal actuators. The microgripper was simulated using electro-thermo-mechanical finite element method (FEM) based on Coventorware 2014 software in order to check the performance of the gripper. As structural material of the microgripper, the SU-8 biocompatible polymer was used during the fabrication process. The metallic micro-heaters were encapsulated in the polymeric actuation structures of the microgrippers to reduce the undesirable out-of-plane displacement of the gripper tips, to reduce the mechanical stress and to improve the thermal efficiency. Experimental testing has been performed to determine the openings of the microgripper tips as function of electrical current. A displacement of the tips of more than 50 pm can be obtained at an electrical current of around 25-26 mA. Over 27-28 mA the heaters are still working but a softening and a damaging status in the polymer were observed.

  17. Compact silicon-based optrode with integrated laser diode chips, SU-8 waveguides and platinum electrodes for optogenetic applications (United States)

    Schwaerzle, M.; Paul, O.; Ruther, P.


    We report on a compact optrode, i.e. a MEMS-based, invasive, bidirectional neural interface allowing to control neural activity using light while neural signals are recorded nearby. The optrode consists of a silicon (Si) base carrying two pairs of bare laser diodes (LDs) emitting at 650 nm and of two 8 mm-long, 250 µm-wide and down to 50 µm-thick shanks extending from the base. Each LD is efficiently coupled to one of four 15 or 20 µm-wide and 13 µm-high SU-8 waveguides (WGs) running in pairs along the shanks. In addition, each shank comprises four 20 µm-diameter platinum electrodes for neural recording near the WG end facets. After encapsulation of the LDs with a Si cover chip blocking stray light and protecting the LDs from the harsh environment to which the probe is destined, the compact base measures only 4  ×  4  ×  0.43 mm3. The time averaged radiant emittance at the WG end facet is 96.9 mW mm-2 for an LD current of 35 mA at a duty cycle of 5%. The absolute electrode impedance at 1 kHz is 1.54  ±  0.06 MΩ. Using infrared thermography, the temperature increase of the probe during LD operation was determined to be about 1 K under neuroscientifically relevant operating conditions.

  18. Loading of Drug-Polymer Matrices in Microreservoirs for Oral Drug Delivery

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh; Keller, Stephan Sylvest; Boisen, Anja


    loading in microfabricated DDS. The microfabricated DDS are microcontainers fabricated in photoresist SU-8 and biopolymer poly-L-lactic-acid (PLLA). Furosemide (F) drug is embedded in poly-ε-caprolactone (PCL) polymer matrix. This F-PCL drug polymer matrix is loaded in SU-8 and PLLA microcontainers using...

  19. A Simple and Reliable PDMS and SU-8 Irreversible Bonding Method and Its Application on a Microfluidic-MEA Device for Neuroscience Research

    Directory of Open Access Journals (Sweden)

    Yufei Ren


    Full Text Available Polydimethylsiloxane (PDMS and SU-8 are currently two very commonly used polymeric materials in the microfluidics field for biological applications. However; there is a pressing need to find a simple, reliable, irreversible bonding method between these two materials for their combined use in innovative integrated microsystems. In this paper, we attempt to investigate the aminosilane-mediated irreversible bonding method for PDMS and SU-8 with X-Ray Photoelectron Spectroscopy (XPS surface analysis and bonding strength tests. Additionally, the selected bonding method was applied in fabricating a microelectrode array (MEA device, including microfluidic features, which allows electrophysiological observations on compartmentalized neuronal cultures. As there is a growing trend towards microfluidic devices for neuroscience research, this type of integrated microdevice, which can observe functional alterations on compartmentalized neuronal culture, can potentially be used for neurodegenerative disease research and pharmaceutical development.

  20. Maintaining evolvability. (United States)

    Crow, James F


    Although molecular methods, such as QTL mapping, have revealed a number of loci with large effects, it is still likely that the bulk of quantitative variability is due to multiple factors, each with small effect. Typically, these have a large additive component. Conventional wisdom argues that selection, natural or artificial, uses up additive variance and thus depletes its supply. Over time, the variance should be reduced, and at equilibrium be near zero. This is especially expected for fitness and traits highly correlated with it. Yet, populations typically have a great deal of additive variance, and do not seem to run out of genetic variability even after many generations of directional selection. Long-term selection experiments show that populations continue to retain seemingly undiminished additive variance despite large changes in the mean value. I propose that there are several reasons for this. (i) The environment is continually changing so that what was formerly most fit no longer is. (ii) There is an input of genetic variance from mutation, and sometimes from migration. (iii) As intermediate-frequency alleles increase in frequency towards one, producing less variance (as p --> 1, p(1 - p) --> 0), others that were originally near zero become more common and increase the variance. Thus, a roughly constant variance is maintained. (iv) There is always selection for fitness and for characters closely related to it. To the extent that the trait is heritable, later generations inherit a disproportionate number of genes acting additively on the trait, thus increasing genetic variance. For these reasons a selected population retains its ability to evolve. Of course, genes with large effect are also important. Conspicuous examples are the small number of loci that changed teosinte to maize, and major phylogenetic changes in the animal kingdom. The relative importance of these along with duplications, chromosome rearrangements, horizontal transmission and polyploidy

  1. Coleman-Weinberg symmetry breaking in SU(8) induced by a third rank antisymmetric tensor scalar field II: the fermion spectrum (United States)

    Adler, Stephen L.


    We continue our study of Coleman-Weinberg symmetry breaking induced by a third rank antisymmetric tensor scalar, in the context of the SU(8) model (Adler 2014 Int. J. Mod. Phys. A 29 1450130) we proposed earlier. We focus in this paper on qualitative features that will determine whether the model can make contact with the observed particle spectrum. We discuss the mechanism for giving the spin \\frac{3}{2} field a mass by the BEH mechanism, and analyze the remaining massless spin \\frac{1}{2} fermions, the global chiral symmetries, and the running couplings after symmetry breaking. We note that the smallest gluon mass matrix eigenvalue has an eigenvector suggestive of U(1) B-L , and conjecture that the theory runs to an infrared fixed point at which there is a massless gluon with 3 to  -1 ratios in generator components. Assuming this, we discuss a mechanism for making contact with the standard model, based on a conjectured asymmetric breaking of Sp(4) to SU(2) subgroups, one of which is the electroweak SU(2), and the other of which is a ‘technicolor’ group that binds the original SU(8) model fermions, which play the role of ‘preons’, into composites. Quarks can emerge as 5 preon composites and leptons as 3 preon composites, with consequent stability of the proton against decay to a single lepton plus a meson. A composite Higgs boson can emerge as a two preon composite. Since anomaly matching for the relevant conserved global symmetry current is not obeyed by three fermion families, emergence of three composite families requires formation of a Goldstone boson with quantum numbers matching this current, which can be a light dark matter candidate.

  2. Microcontainers for Intestinal Drug Delivery

    DEFF Research Database (Denmark)

    Tentor, Fabio; Mazzoni, Chiara; Keller, Stephan Sylvest

    Among all the drug administration routes, the oral one is the most preferred by the patients being less invasive, faster and easier. Oral drug delivery systems designed to target the intestine are produced by powder technology and capsule formulations. Those systems including micro- and nano-particulate...

  3. Evaluation of Effective Elastic, Piezoelectric, and Dielectric Properties of SU8/ZnO Nanocomposite for Vertically Integrated Nanogenerators Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Neelam Mishra


    Full Text Available A nanogenerator is a nanodevice which converts ambient mechanical energy into electrical energy. A piezoelectric nanocomposite, composed of vertical arrays of piezoelectric zinc oxide (ZnO nanowires, encapsulated in a compliant polymeric matrix, is one of most common configurations of a nanogenerator. Knowledge of the effective elastic, piezoelectric, and dielectric material properties of the piezoelectric nanocomposite is critical in the design of a nanogenerator. In this work, the effective material properties of a unidirectional, unimodal, continuous piezoelectric composite, consisting of SU8 photoresist as matrix and vertical array of ZnO nanowires as reinforcement, are systematically evaluated using finite element method (FEM. The FEM simulations were carried out on cubic representative volume elements (RVEs. Four different types of arrangements of ZnO nanowires and three sizes of RVEs have been considered. The volume fraction of ZnO nanowires is varied from 0 to a maximum of 0.7. Homogeneous displacement and electric potential are prescribed as boundary conditions. The material properties are evaluated as functions of reinforcement volume fraction. The values obtained through FEM simulations are compared with the results obtained via the Eshelby-Mori-Tanaka micromechanics. The results demonstrate the significant effects of ZnO arrangement, ZnO volume fraction, and size of RVE on the material properties.

  4. Ergonomics Contribution in Maintainability (United States)

    Teymourian, Kiumars; Seneviratne, Dammika; Galar, Diego


    The objective of this paper is to describe an ergonomics contribution in maintainability. The economical designs, inputs and training helps to increase the maintainability indicators for industrial devices. This analysis can be helpful, among other cases, to compare systems, to achieve a better design regarding maintainability requirements, to improve this maintainability under specific industrial environment and to foresee maintainability problems due to eventual changes in a device operation conditions. With this purpose, this work first introduces the notion of ergonomics and human factors, maintainability and the implementation of assessment of human postures, including some important postures to perform maintenance activities. A simulation approach is used to identify the critical posture of the maintenance personnel and implements the defined postures with minimal loads on the personnel who use the equipment in a practical scenario. The simulation inputs are given to the designers to improve the workplace/equipment in order to high level of maintainability. Finally, the work concludes summarizing the more significant aspects and suggesting future research.

  5. Manually Maintained Serials Records. (United States)

    Ortopan, LeRoy D.; And Others

    At the American Library Association Annual Conference in Dallas in 1971, the Serials Section of the Resources and Technical Services Division established a committee to produce a state-of-the-art report on the maintenance of serial records by manual methods in all types of libraries. The Ad Hoc Committee to Study Manually Maintained Serials…

  6. Maintaining dignity in vulnerability

    DEFF Research Database (Denmark)

    Høy, Bente


    to understand the meaning of the narrated text. Results. The meaning of maintaining dignity was constituted in a sense of vulnerability to the self, and elucidated in three major interrelated themes: Being involved as a human being, being involved as the person one is and strives to become, and being involved...

  7. Nuclear power plant maintainability. (United States)

    Seminara, J L; Parsons, S O


    In the mid-1970s a general awareness of human factors engineering deficiencies associated with power plant control rooms took shape and the Electric Power Research Institute (EPRI) awarded the Lockheed Corporation a contract to review the human factors aspects of five representative operational control rooms and their associated simulators. This investigation revealed a host of major and minor deficiencies that assumed unforeseen dimensions in the post- Three Mile Island accident period. In the course of examining operational problems (Seminara et al, 1976) and subsequently the methods for overcoming such problems (Seminara et al, 1979, 1980) indications surfaced that power plants were far from ideal in meeting the needs of maintenance personnel. Accordingly, EPRI sponsored an investigation of the human factors aspects of power plant maintainability (Seminara, 1981). This paper provides an overview of the maintainability problems and issues encountered in the course of reviewing five nuclear power plants.

  8. Maintaining Relationship Based Procurement

    Directory of Open Access Journals (Sweden)

    Peter Davis


    Full Text Available Alliance and relationship projects are increasingin number and represent a large pool of work. Tobe successful relationship style contracts dependon soft-dollar factors, particularly the participants'ability to work together within an agreedframework, generally they are not based on lowbid tendering. Participants should be prepared todo business in an open environment based ontrust and mutually agreed governance. Theresearch evaluates relationship maintenance inthe implementation phase of constructionalliances - a particular derivative of relationshipstyle contracts. To determine the factors thatcontribute to relationship maintenance forty-nineexperienced Australian alliance projectmanagers were interviewed. The main findingswere; the development of relationships early inthe project form building blocks of success fromwhich relationships are maintained and projectvalue added; quality facilitation plays animportant part in relationship maintenance and ahybrid organisation created as a result of alliancedevelopment overcomes destructiveorganisational boundaries. Relationshipmaintenance is integral to alliance project controland failure to formalise it and pay attention toprocess and past outcomes will undermine analliance project's potential for success.

  9. In situ SU-8 silver nanocomposites

    DEFF Research Database (Denmark)

    Fischer, Søren Vang; Uthuppu, Basil; Jakobsen, Mogens Havsteen


    Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to...

  10. Maintaining Web Cache Coherency

    Directory of Open Access Journals (Sweden)


    Full Text Available Document coherency is a challenging problem for Web caching. Once the documents are cached throughout the Internet, it is often difficult to keep them coherent with the origin document without generating a new traffic that could increase the traffic on the international backbone and overload the popular servers. Several solutions have been proposed to solve this problem, among them two categories have been widely discussed: the strong document coherency and the weak document coherency. The cost and the efficiency of the two categories are still a controversial issue, while in some studies the strong coherency is far too expensive to be used in the Web context, in other studies it could be maintained at a low cost. The accuracy of these analysis is depending very much on how the document updating process is approximated. In this study, we compare some of the coherence methods proposed for Web caching. Among other points, we study the side effects of these methods on the Internet traffic. The ultimate goal is to study the cache behavior under several conditions, which will cover some of the factors that play an important role in the Web cache performance evaluation and quantify their impact on the simulation accuracy. The results presented in this study show indeed some differences in the outcome of the simulation of a Web cache depending on the workload being used, and the probability distribution used to approximate updates on the cached documents. Each experiment shows two case studies that outline the impact of the considered parameter on the performance of the cache.

  11. Assessing optimal software architecture maintainability

    NARCIS (Netherlands)

    Bosch, Jan; Bengtsson, P.O.; Smedinga, Rein; Sousa, P; Ebert, J


    Over the last decade, several authors have studied the maintainability of software architectures. In particular, the assessment of maintainability has received attention. However, even when one has a quantitative assessment of the maintainability of a software architecture, one still does not have

  12. A Maintainability Checklist for Spreadsheets


    Vlootman, Henk; Hermans, Felienne


    Spreadsheets are widely used in industry, because they are flexible and easy to use. Often, they are even used for business-critical applications. It is however difficult for spreadsheet users to correctly assess the maintainability of spreadsheets. Maintainability of spreadsheets is important, since spreadsheets often have a long lifespan, during which they are used by several users. In this paper, we present a checklist aimed at measuring the maintainability of a spreadsheet. This is achiev...

  13. Marshal: Maintaining Evolving Models Project (United States)

    National Aeronautics and Space Administration — SIFT proposes to design and develop the Marshal system, a mixed-initiative tool for maintaining task models over the course of evolving missions. Marshal-enabled...

  14. Maintaining Healthy Skin -- Part 1 (United States)

    ... problems. Tips for maintaining good skin care: Avoid soaps labeled "antibacterial" or "antimicrobial." These tend to reduce the skin's acidity, which acts as a protection from infection. Keep the skin clean and dry. Wash with soap and water daily, then rinse and dry thoroughly. ...


    NARCIS (Netherlands)



    An algorithm is presented to maintain the visibility graph of a set of N line segments in the plane in O(log2 N + K log N) time, where K is the total number of arcs of the visibility graph that are destroyed or created upon insertion or deletion of a line segment. The line segments should be

  16. Disturbance maintains alternative biome states. (United States)

    Dantas, Vinícius de L; Hirota, Marina; Oliveira, Rafael S; Pausas, Juli G


    Understanding the mechanisms controlling the distribution of biomes remains a challenge. Although tropical biome distribution has traditionally been explained by climate and soil, contrasting vegetation types often occur as mosaics with sharp boundaries under very similar environmental conditions. While evidence suggests that these biomes are alternative states, empirical broad-scale support to this hypothesis is still lacking. Using community-level field data and a novel resource-niche overlap approach, we show that, for a wide range of environmental conditions, fire feedbacks maintain savannas and forests as alternative biome states in both the Neotropics and the Afrotropics. In addition, wooded grasslands and savannas occurred as alternative grassy states in the Afrotropics, depending on the relative importance of fire and herbivory feedbacks. These results are consistent with landscape scale evidence and suggest that disturbance is a general factor driving and maintaining alternative biome states and vegetation mosaics in the tropics. © 2015 John Wiley & Sons Ltd/CNRS.

  17. Maintaining protein composition in cilia. (United States)

    Stephen, Louise A; Elmaghloob, Yasmin; Ismail, Shehab


    The primary cilium is a sensory organelle that is vital in regulating several signalling pathways. Unlike most organelles cilia are open to the rest of the cell, not enclosed by membranes. The distinct protein composition is crucial to the function of cilia and many signalling proteins and receptors are specifically concentrated within distinct compartments. To maintain this composition, a mechanism is required to deliver proteins to the cilium whilst another must counter the entropic tendency of proteins to distribute throughout the cell. The combination of the two mechanisms should result in the concentration of ciliary proteins to the cilium. In this review we will look at different cellular mechanisms that play a role in maintaining the distinct composition of cilia, including regulation of ciliary access and trafficking of ciliary proteins to, from and within the cilium.

  18. NMG documentation, part 3: maintainer`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, F.N.; Dickinson, R.P. Jr.


    This is the third of a three-part report documenting NMG, the Numerical Mathematics Guide. Part I is aimed at the user of the systenL It contains an introduction, with an out- line of the complete report, and Chapter 1, User`s Point of View. Part II is aimed at the programmer and contains Chapter 2, How It Works. Part III is aimed at the maintainer of NMG and contains Chapter 3, Maintenance, and Chapter 4, Validation. Because its contents are so specialized, Part III will receive only limited distribution. Note that each chapter has its own page numbering and table of contents.

  19. Spacecraft reliability/maintainability optimization. (United States)

    Sharmahd, J. N.


    Description of a procedure to develop a methodology to optimize man-serviced systems for reliability and maintainability. The spacecraft systems are analyzed using failure modes and effects analysis and maintenance analysis, component mean-time-between failure, duty cycle, type of redundancy, and cost information to develop parametric data on various time intervals. Included are crew time-to-repair, cost, weight, and volume effects of increasing subsystem reliability above the baseline. Results are presented for space systems using the existing data from a research and applications module. These results show the minimum cost of sustaining mission operations.

  20. Photochemical modification and patterning of SU-8 using Anthraquinone photolinkers

    DEFF Research Database (Denmark)

    Blagoi, Gabriela; Keller, Stephan Urs; Persson, Karl Fredrik


    of micropatterned AQ molecules is improved to 1.5 μm when a collimated light source is used. This micropatterning process will be important for the functionalization of MEMS-based biosensors. The method saves several processing steps and can be integrated in cleanroom fabrication thus avoiding contamination...

  1. Simulation of SU-8 frequency-driven scratch drive actuators

    KAUST Repository

    Conchouso Gonzalez, David


    This paper presents the simulation of Scratch Drive Actuators (SDAs) for micro-robotic applications. SDAs use electrostatic forces to generate motion on top of an interdigitated electrode array. The purpose of this investigation is to evaluate several design geometries and micro-actuator configurations using ConventorWare®\\'s finite element analysis module. The study performed investigates the SDAs modal and electrostatic behavior and the effects of linking two or more SDAs together in a microrobot device. In addition, the interdigitated electrode array performance, used for power delivery, was studied by changing the thickness of its dielectric layer. We present our observations based on these studies, which will aid in the understanding and development of future SDA designs. © 2013 IEEE.

  2. SU-8 photoresist-derived electrospun carbon nanofibres as high ...

    Indian Academy of Sciences (India)

    Author Affiliations. M KAKUNURI1 S KAUSHIK1 A SAINI1 C S SHARMA1. Creative and Advanced Research Based On Nanomaterials (CARBON) Laboratory, Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Kandi 502285, India ...

  3. SU-8 photoresist-derived electrospun carbon nanofibres as high ...

    Indian Academy of Sciences (India)


    Jun 9, 2017 ... Carbon nanofibres (CNF), due to their advantages like large surface area and thus enhanced interface of electrolyte and active material surface, short Li ion transport distances and high resilience to volume expansion during cycling even at high current densities, have drawn a great attention for being used ...

  4. Encapsulation method for maintaining biodecontamination activity

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Robert D. (Idaho Falls, ID); Hamilton, Melinda A. (Idaho Falls, ID); Nelson, Lee O. (Idaho Falls, ID); Benson, Jennifer (Cockermouth, GB); Green, Martin J. (Wooton, GB); Milner, Timothy N. (Centerville, VA)


    A method for maintaining the viability and subsequent activity of microorganisms utilized in a variety of environments to promote biodecontamination of surfaces. One application involves the decontamination of concrete surfaces. Encapsulation of microbial influenced degradation (MID) microorganisms has shown that MID activity is effectively maintained under passive conditions, that is, without manual addition of moisture or nutrients, for an extended period of time.

  5. maintainability of manpower system with restricted recruitment

    African Journals Online (AJOL)


    led to other important results. KEY WORDS: Manpower structure, Maintainability, Factors of flow, Markov model Probability. INTRODUCTION. Maintainability is an aspect ... What is common in the above types of statistical manpower control is that only one factor of flow is controlled. ..... Journal of Mathematical Sciences, Vol.

  6. Fabrication and loading of microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh

    Oral drug delivery is considered as the most patient compliant delivery route. However, it faces many obstacles, especially due to the ever-increasing number of drugs that are poorly soluble and barely absorbed in the gastro-intestinal tract. Moreover, drugs can degrade in the harsh acidic...... environment of stomach before they reach the intestine. These issues lead to reduced bioavailability of active ingredients. To combat that novel oral drug delivery systems have been developed. Some of these systems that have gained significant interest in this field are reservoir based drug delivery...... microfabrication methods with materials such as Si and photoresists. However, there is a need to shift from these materials towards biocompatible and biodegradable polymers such as poly-l-lactic acid (PLLA) or poly-e-caprolactone (PCL). Hot embossing is one of the most viable and matured methods to fabricate...

  7. Fabrication and loading of microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh

    is an important loop diuretic drug with low solubility and permeability is used as a model drug and embedded in a PCL matrix. The crystallinity of the drug is tailored by the process parameters of spin coating. Release profiles ranging from rapid burst release to sustained zero-order release are obtained......Oral drug delivery is considered as the most patient compliant delivery route. However, it faces many obstacles, especially due to the ever-increasing number of drugs that are poorly soluble and barely absorbed in the gastro-intestinal tract. Moreover, drugs can degrade in the harsh acidic...... microfabrication methods with materials such as Si and photoresists. However, there is a need to shift from these materials towards biocompatible and biodegradable polymers such as poly-l-lactic acid (PLLA) or poly-e-caprolactone (PCL). Hot embossing is one of the most viable and matured methods to fabricate...

  8. Coastal Maintained Channels in US waters (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This layer shows coastal channels and waterways that are maintained and surveyed by the U.S. Army Corps of Engineers (USACE). These channels are necessary...

  9. Wnt: what's needed to maintain pluripotency? (United States)

    Niwa, Hitoshi


    A precise role for the canonical Wnt pathway in maintaining pluripotency in mouse embryonic stem cells (mESCs) has been debated. Four recent reports add pieces to the puzzle and together these results may help establish a robust model.

  10. Cover for maintaining roofing in cleaning shafts

    Energy Technology Data Exchange (ETDEWEB)

    Altukhov, V.I.; Bazarov, V.D.; Belostotskiy, B.Kh.; Kuzmenko, N.S.; Mukhin, Ye.P.; Podolyako, N.I.


    The purpose of the invention is to improve reliability of maintaining roofing of inclined beds. This goal is achieved because in the cover for maintaining roofing in the extraction drifts, which includes upper sections with openings interconnected by a beam with a spacing wedge equipped with an axis for installation of an opening in the upper section and cantilevers for the upper sections and spacing wedge and arranged eccentrically in relation to the longitudinal axis of the cover, the beam axis is made with outer annular groove.

  11. Maintaining professional boundaries: keep your distance. (United States)

    Griffith, Richard; Tengnah, Cassam


    Maintaining professional boundaries is essential to an effective nurse-patient relation whose sole focus must be on the care and treatment needs of the patient. Complaints about failures to maintain professional boundaries are increasing, with the Nursing and Midwifery Council reporting some 247 new cases in the year 2012-12. The article outlines the scope of the nurse-patient relationship, what activity is considered to be outside the professional and considers the consequences for community nurses if they are found to have breached a professional boundary.

  12. Sustainability Of The 21M Missile Maintainer (United States)


    PROFESSIONAL STUDIES PAPER: SUSTAINABILITY OF THE 21M MISSILE MAINTAINER LIEUTENANT COLONEL DAVID S. MILLER AIR...of the health and sustainability of the ICBM maintenance officer career field will reveal conclusions and recommendations that could assist the...maintenance career field as healthy and sustainable , and ready to flourish. However, the evidence presented in this paper will show otherwise. To

  13. Coping under pressure: Strategies for maintaining confidence ...

    African Journals Online (AJOL)


    Aug 11, 2010 ... Sport coaching can be a fulfilling and rewarding occupation, but can also be stressful because of the demands and ... responsible for athletes and their performance (Wynd 2007:2). Apart from the external factors ..... their strategies to nurture and maintain a healthy workforce. Whilst these changes could ...

  14. The randomized complexity of maintaining the minimum

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Chaudhuri, Shiva; Radhakrishnan, Jaikumar


    The complexity of maintaining a set under the operations Insert, Delete and FindMin is considered. In the comparison model it is shown that any randomized algorithm with expected amortized cost t comparisons per Insert and Delete has expected cost at least n/(e22t)-1 comparisons for FindMin. If F...

  15. Maintaining ideal body weight counseling sessions

    Energy Technology Data Exchange (ETDEWEB)

    Brammer, S.H.


    The purpose of this program is to provide employees with the motivation, knowledge and skills necessary to maintain ideal body weight throughout life. The target audience for this program, which is conducted in an industrial setting, is the employee 40 years of age or younger who is at or near his/her ideal body weight.

  16. Maintainability of manpower system with restricted recruitment ...

    African Journals Online (AJOL)

    The maintainability of a manpower system is studied under a Markov framework. The classical method of controlling only one factor of flow is extended to highlight the case in which two factors are under control simultaneously. One special case of this extension, where recruitment of units faces partial embargo, is given, ...

  17. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Mølhave, Thomas; Revsbæk, Morten


    We study the problem of maintaining the contour tree T of a terrain Sigma, represented as a triangulated xy-monotone surface, as the heights of its vertices vary continuously with time. We characterize the combinatorial changes in T and how they relate to topological changes in Sigma. We present...... an augmented contour tree and a join/split tree....

  18. Pedagogical Practices: Nurturing and Maintaining Democratic Habits (United States)

    Hubler-Larimore, Lucretia Marie


    This case study examined the pedagogical practices of four teachers of one public elementary school whose mission seeks to nurture and maintain democratic habits for participation in a democratic society. Historically, public schools have been charged with the duty of preparing young minds to live within in a democratic society and as such this…

  19. How Do Positive Views Maintain Life Satisfaction? (United States)

    Wu, Chia-Huei; Tsai, Ying-Mei; Chen, Lung Hung


    This study proposes three mediation pathways to explain how the positive views (perceived control, optimism and self-enhancement) proposed by Cummins and Nistico (Journal of Happiness Studies 3:37-69 2002) maintain life satisfaction. The three pathways were enhancing self-esteem, reducing have-want discrepancy and changing importance perceptions.…


    African Journals Online (AJOL)

    Kevin Wangwe Ongeti


    Jan 2, 2013 ... have resulted in wide disparities in curriculum design teaching methods, number and composition of instructors. Inspite of the challenges, the Department of Human Anatomy of the University of Nairobi. (UON) maintained excellence of teaching for over 40yrs. This article describes the teaching of anatomy.

  1. Breeding and maintaining high-quality insects

    DEFF Research Database (Denmark)

    Jensen, Kim; Kristensen, Torsten Nygård; Heckmann, Lars-Henrik


    Insects have a large potential for sustainably enhancing global food and feed production, and commercial insect production is a rising industry of high economic value. Insects suitable for production typically have fast growth, short generation time, efficient nutrient utilization, high...... in a starting phase. Here, we discuss the challenges and precautions that need to be considered when breeding and maintaining high-quality insect populations for food and feed. This involves techniques typically used in domestic animal breeding programs including maintaining genetically healthy populations...... reproductive potential, and thrive at high density. Insects may cost-efficiently convert agricultural and industrial food by-products into valuable protein once the technology is finetuned. However, since insect mass production is a new industry, the technology needed to efficiently farm these animals is still...

  2. Maintaining patient accounts performance during downsizing. (United States)

    Senters, E M


    Patient accounts managers and chief financial officers (CFOs) are facing difficult issues during this current period of change in health care. The realities of today's lower rates of reimbursement and the uncertainties of healthcare reform have forced hospital management teams to reduce costs strategically to maintain adequate financial performance. One method often employed is "downsizing"--reducing staffing levels. Even those facilities that have not found it necessary to reduce staff through a formal layoff plan must seriously evaluate whether or not to replace employees who retire or terminate voluntarily. Patient accounts departments that have not yet been forced to downsize should be prepared for such an event; those that are currently struggling to maintain performance as a result of downsizing can improve their operations by addressing certain key areas.

  3. Maintain Stability Operations Capability During Military Operations (United States)


    Readiness Training Center (JRTC) – Fort Polk, LA; the Joint Multinational Readiness Center (JRMC) in Hohenfels , Germany; and the Joint National Training...Teams (FETs), etc. Maintaining a synergistic approach and gaining more multinational training partners each year, the JRMC, in Hohenfels , , (Accessed January 2013) 41 Home page, Joint Multinational Readiness Center (JRMC), Hohenfels , Germany, 2013,

  4. Methods for maintaining insect cell cultures


    Dwight E. Lynn


    Insect cell cultures are now commonly used in insect physiology, developmental biology, pathology, and molecular biology. As the field has advanced from methods development to a standard procedure, so has the diversity of scientists using the technique. This paper describes methods that are effective for maintaining various insect cell lines. The procedures are differentiated between loosely or non-attached cell strains, attached cell strains, and strongly adherent cell strains.

  5. Alertness maintaining tasks (AMTs) while driving. (United States)

    Oron-Gilad, Tal; Ronen, Adi; Shinar, David


    We evaluated the effectiveness of alertness maintaining tasks (AMTs) on driver performance, subjective feelings, and psychophysiological state in monotonous simulated driving in two experiments. In the first experiment, 12 professional truck drivers participated in five sessions of simulated driving: driving only, driving with one of three AMTs (counterbalanced), and driving while listening to music. AMTs were not equally effective in maintaining alertness. The trivia AMT prevented driving performance deterioration, and increased alertness (measured by standardized HRV). The choice reaction time AMT was least demanding but also increased subjective sleepiness and reduced arousal (measured by alpha/beta ratio). The working memory AMT caused a significant decrement in driving speed, increased subjective fatigue, and was regarded by the participants as detrimental to driving. Trivia was preferred by the majority of the drivers over the other two AMTs. Experiment 2 further examined the utility of the trivia AMT. When the drivers engaged in the trivia AMT they maintained better driving performance and perceived the driving duration as shorter than the control condition. The two experiments demonstrated that AMTs can have a positive effect on alertness. The effect is localized in the sense that it does not persist beyond the period of the AMT activation.

  6. Store operations to maintain cache coherence

    Energy Technology Data Exchange (ETDEWEB)

    Evangelinos, Constantinos; Nair, Ravi; Ohmacht, Martin


    In one embodiment, a computer-implemented method includes encountering a store operation during a compile-time of a program, where the store operation is applicable to a memory line. It is determined, by a computer processor, that no cache coherence action is necessary for the store operation. A store-without-coherence-action instruction is generated for the store operation, responsive to determining that no cache coherence action is necessary. The store-without-coherence-action instruction specifies that the store operation is to be performed without a cache coherence action, and cache coherence is maintained upon execution of the store-without-coherence-action instruction.

  7. Store operations to maintain cache coherence

    Energy Technology Data Exchange (ETDEWEB)

    Evangelinos, Constantinos; Nair, Ravi; Ohmacht, Martin


    In one embodiment, a computer-implemented method includes encountering a store operation during a compile-time of a program, where the store operation is applicable to a memory line. It is determined, by a computer processor, that no cache coherence action is necessary for the store operation. A store-without-coherence-action instruction is generated for the store operation, responsive to determining that no cache coherence action is necessary. The store-without-coherence-action instruction specifies that the store operation is to be performed without a cache coherence action, and cache coherence is maintained upon execution of the store-without-coherence-action instruction.

  8. Bootstrapping and Maintaining Trust in the Cloud (United States)


    version 1.2 uses SHA-1 for measure- ments. TPM specification version 2.0 adds SHA-256 to ad- dress cryptographic weaknesses in SHA-1. Integrity by bandwidth and requires more costs to maintain resources outside of the cloud. Option 3 is a good trade -off between cost and performance for a... trade -offs of these options including a low-cost registrar and CV appli- ance (Option 3) we implemented on a Raspberry Pi. Once we have created the tenant

  9. Mothers in prison: maintaining connections with children. (United States)

    Mignon, Sylvia I; Ransford, Paige


    The significant increase in the number of incarcerated women ensures that many children must live without their mothers for some period of time. Women in prison were interviewed about their efforts to maintain relationships with their children. Mail and telephone contacts were more frequent than actual visits. Almost one half of mothers had never received a visit from their children. This article identifies challenges to the development and maintenance of contact between incarcerated mothers and their children. Recommendations are made for correctional agencies to enhance opportunities for incarcerated mothers to foster positive connections with their children.

  10. Maintaining Consistency of Data on the Web


    Bernauer, Martin


    Increasingly more data is becoming available on the Web, estimates speaking of 1 billion documents in 2002. Most of the documents are Web pages whose data is considered to be in XML format, expecting it to eventually replace HTML. A common problem in designing and maintaining a Web site is that data on a Web page often replicates or derives from other data, the so-called base data, that is usually not contained in the deriving or replicating page. Consequently, replicas and derivations become...

  11. Take Control of Maintaining Your Mac

    CERN Document Server

    Kissell, Joe


    Keep your Mac running smoothly with our easy maintenance program! Regular maintenance is necessary to avoid problems and to ensure your Mac runs at peak performance, but it's hard to know what to do and when to do it. Best-selling author Joe Kissell has now applied his commonsense approach to the task of maintaining your Mac, whether you use Tiger or Leopard! Learn how to start on the right foot; what you should do daily, weekly, monthly, and yearly; and how to prepare for Mac OS X updates. Joe even explains how to monitor your Mac's health and debunks common panaceas. Read this book to lea

  12. Can we successfully maintain risk patients? (United States)

    Darby, M


    The most fundamental premise in the current view of periodontal disease is that not all individuals are at equal risk for disease and disease progression. Studies reveal that about 5-20% of the population is at risk for severe disease progression. The purpose of this paper is to define at-risk patients, review risk factors and indicators of disease progression, and outline an evidence-based strategy that includes both self-care and professional care for maintaining periodontal health. Risk factors/risk indicators considered include history of previous disease, increased pocket depth and loss of clinical attachment, frequency of dental care, specific bacterial pathogens, and systemic/environmental host factors such as smoking, diabetes mellitus, genetics, and stress. Because host factors may have more influence on disease progression than periodontal pathogens, personal and professional maintenance care must include the role of the host in periodontal disease progression. By examining the evidence surrounding these complex issues, dentists and dental hygienists are able to determine the extent to which evidence supports available approaches to maintain periodontal health and control disease progression.

  13. Maintaining Intergenerational Solidarity in Mexican Transnational Families

    Directory of Open Access Journals (Sweden)

    Catherine A. Solheim


    Full Text Available This study explored how Mexican transnational families maintain intergenerational relationships, using five of the dimensions of the intergenerational solidarity framework. Interview data from 13 adult migrant children who lived in the U.S. and their parents who lived in Mexico were analyzed. Structural solidarity was challenged by great distance between families. Families maintained associational solidarity by making contact frequently, though visiting was often restricted by lack of documentation. Functional solidarity was expressed through financial support to parents. This involved remittances sent to parents. However, it should be noted that it was often migrants’ siblings in Mexico who managed these remittances. Affectual solidarity was expressed through statements of love and concern for one another. Normative solidarity and consensual solidarity reflected the value of familismo through financial support and the desire to live together. Several dimensions of intergenerational solidarity are interconnected. This study provides evidence for the relevance of the intergenerational solidarity framework in transnational families and suggests that geographic context is relevant when studying intergenerational relationships.

  14. Does PKM(zeta) maintain memory? (United States)

    Kwapis, Janine L; Helmstetter, Fred J


    Work on the long-term stability of memory has identified a potentially critical role for protein kinase Mzeta (PKMζ) in maintaining established memory. PKMζ, an autonomously active isoform of PKC, is hypothesized to sustain those changes that occurred during memory formation in order to preserve the memory engram over time. Initial studies investigating the role of PKMζ were largely successful in demonstrating a role for the kinase in memory maintenance; disrupting PKMζ activity with ζ-inhibitory peptide (ZIP) was successful in disrupting a variety of established associations in a number of key brain regions. More recent work, however, has questioned both the role of PKMζ in memory maintenance and the effectiveness of ZIP as a specific inhibitor of PKMζ activity. Here, we outline the research both for and against the idea that PKMζ is a memory maintenance mechanism and discuss how these two lines of research can be reconciled. We conclude by proposing a number of studies that would help to clarify the role of PKMζ in memory and define other mechanisms the brain may use to maintain memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Design guidelines for remotely maintained equipment

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, T.W.; Evans, J.H.; Peishel, F.L.; Schrock, S.L.; Smith, G.E.; Macdonald, D.


    The CFRP has pioneered and developed the concept of totally remote operation and maintenance of process equipment in spent fuel reprocessing, using force-reflecting master/slave servomanipulators, coupled with television viewing, to extend human capabilities effectively throughout an uninhabitable environment. This concept enhances safeguard control of nuclear materials, provides for low-exposure of personnel to radiation and reliable recovery from unplanned events, ensures high plant availability, and aids eventual decommissioning of the plant. The results of this experience have been organized in this document to enable designers to consider this technology, not only in spent fuel reprocessing, but among various other situations that may be hazardous to personnel. This document is an expanded and updated version of an earlier design guide that was specific to fuel reprocessing requirements. The guidelines identified in the present document suggest a general approach to the design of effective, reliable, safe, remotely operated and maintained facilities. This document may be used broadly to apply remotely maintained equipment in hostile environments based on proven techniques, equipment, and well-established practices. The concepts are particularly applicable to large plant facilities where economy of scale is important. The theme emphasizes utilization of ordinary commercial tools, equipment, and materials widely available. 5 refs., 51 figs., 10 tabs.

  16. Chewing Maintains Hippocampus-Dependent Cognitive Function (United States)

    Chen, Huayue; Iinuma, Mitsuo; Onozuka, Minoru; Kubo, Kin-Ya


    Mastication (chewing) is important not only for food intake, but also for preserving and promoting the general health. Recent studies have showed that mastication helps to maintain cognitive functions in the hippocampus, a central nervous system region vital for spatial memory and learning. The purpose of this paper is to review the recent progress of the association between mastication and the hippocampus-dependent cognitive function. There are multiple neural circuits connecting the masticatory organs and the hippocampus. Both animal and human studies indicated that cognitive functioning is influenced by mastication. Masticatory dysfunction is associated with the hippocampal morphological impairments and the hippocampus-dependent spatial memory deficits, especially in elderly. Mastication is an effective behavior for maintaining the hippocampus-dependent cognitive performance, which deteriorates with aging. Therefore, chewing may represent a useful approach in preserving and promoting the hippocampus-dependent cognitive function in older people. We also discussed several possible mechanisms involved in the interaction between mastication and the hippocampal neurogenesis and the future directions for this unique fascinating research. PMID:26078711

  17. [Maintaining solidarity: is mutuality the solution?]. (United States)

    Gevers, J K M; Ploem, M C


    Solidarity is essentially the willingness to contribute to the community and its demands, which may even involve contributing more than one is expecting to receive. Another principle is mutuality: this refers to a balance between rights and obligations or between mutual obligations. In its advisory document 'The importance of mutuality......solidarity takes work!', The Dutch Council for Public Health and Health Care underlines the importance of ensuring solidarity within the Dutch health care system, e.g. by encouraging patients to take responsibility for their own health, possibly by introducing elements of mutuality. In our contribution, we comment on the Council's advice. Although we fully agree with the overall conclusion that solidarity should be maintained within the system, we do not see how the introduction of increased mutuality will contribute to this goal.

  18. Maintaining and troubleshooting your 3D printer

    CERN Document Server

    Bell, Charles


    Maintaining and Troubleshooting Your 3D Printer by Charles Bell is your guide to keeping your 3D printer running through preventive maintenance, repair, and diagnosing and solving problems in 3D printing. If you've bought or built a 3D printer such as a MakerBot only to be confounded by jagged edges, corner lift, top layers that aren't solid, or any of a myriad of other problems that plague 3D printer enthusiasts, then here is the book to help you get past all that and recapture the joy of creative fabrication. The book also includes valuable tips for builders and those who want to modify the

  19. Motives for maintaining personal journal blogs. (United States)

    Hollenbaugh, Erin E


    Although much has been learned about political and news blogs, there has been a lack of research on personal journal blogs. They deserve further research attention because of the implications blogs have in many bloggers' immediate social networks, as well as the opportunities for scientific inquiry in a rich and evolving communication environment. This study explored bloggers' motives for maintaining personal journal blogs, or blogs that resemble diaries about one's personal life. Stemming from the uses and gratifications perspective, antecedents (age, sex, loneliness, disclosiveness) and blogging motives composed a model for predicting the amount of blog use. Seven motives emerged from online survey data: helping/informing, social connection, pass time, exhibitionism, archiving/organizing, professionalism, and get feedback. Age, sex, loneliness, and disclosiveness predicted different motives, and the total model (age, sex, loneliness, disclosiveness, and motives) was useful for explaining 13% of the variance in the amount of blog use.

  20. CDC20 maintains tumor initiating cells (United States)

    Xie, Qi; Wu, Qiulian; Mack, Stephen C.; Yang, Kailin; Kim, Leo; Hubert, Christopher G.; Flavahan, William A.; Chu, Chengwei; Bao, Shideng; Rich, Jeremy N.


    Glioblastoma is the most prevalent and lethal primary intrinsic brain tumor. Glioblastoma displays hierarchical arrangement with a population of self-renewing and tumorigenic glioma tumor initiating cells (TICs), or cancer stem cells. While non-neoplastic neural stem cells are generally quiescent, glioblastoma TICs are often proliferative with mitotic control offering a potential point of fragility. Here, we interrogate the role of cell-division cycle protein 20 (CDC20), an essential activator of anaphase-promoting complex (APC) E3 ubiquitination ligase, in the maintenance of TICs. By chromatin analysis and immunoblotting, CDC20 was preferentially expressed in TICs relative to matched non-TICs. Targeting CDC20 expression by RNA interference attenuated TIC proliferation, self-renewal and in vivo tumor growth. CDC20 disruption mediated its effects through induction of apoptosis and inhibition of cell cycle progression. CDC20 maintains TICs through degradation of p21CIP1/WAF1, a critical negative regulator of TICs. Inhibiting CDC20 stabilized p21CIP1/WAF1, resulting in repression of several genes critical to tumor growth and survival, including CDC25C, c-Myc and Survivin. Transcriptional control of CDC20 is mediated by FOXM1, a central transcription factor in TICs. These results suggest CDC20 is a critical regulator of TIC proliferation and survival, linking two key TIC nodes – FOXM1 and p21CIP1/WAF1 — elucidating a potential point for therapeutic intervention. PMID:25938542

  1. Developing and maintaining reflection in clinical journals. (United States)

    Paterson, B L


    There is a pressing need in today's world for nurses who are willing and able to transform health care. Teaching strategies that foster reflection are in order. The use of dialogue journals has been widely reported in the nursing literature as an effective strategy for assisting students to reflect about learning experiences in the clinical area. Despite the promise that journal writing will enhance students' ability to reflect on their clinical learning experiences, not all students respond positively to journal writing as a learning tool. The paper is a discussion of some of the common difficulties that arise in the use of clinical journals as a reflective strategy in nursing education. Common problems in the use of clinical journals include procrastination; superficial, nonreflective entries; waning enthusiasm about the activity; and unwillingness or inability to reflect. The possible etiologies for these problems will be explored. Specifically, the paper will focus on ways to prevent or minimize these concerns by maintaining and enhancing the factors required for students to reflect in clinical journals.

  2. How RNA viruses maintain their genome integrity. (United States)

    Barr, John N; Fearns, Rachel


    RNA genomes are vulnerable to corruption by a range of activities, including inaccurate replication by the error-prone replicase, damage from environmental factors, and attack by nucleases and other RNA-modifying enzymes that comprise the cellular intrinsic or innate immune response. Damage to coding regions and loss of critical cis-acting signals inevitably impair genome fitness; as a consequence, RNA viruses have evolved a variety of mechanisms to protect their genome integrity. These include mechanisms to promote replicase fidelity, recombination activities that allow exchange of sequences between different RNA templates, and mechanisms to repair the genome termini. In this article, we review examples of these processes from a range of RNA viruses to showcase the diverse approaches that viruses have evolved to maintain their genome sequence integrity, focusing first on mechanisms that viruses use to protect their entire genome, and then concentrating on mechanisms that allow protection of the genome termini, which are especially vulnerable. In addition, we discuss examples in which it might be beneficial for a virus to 'lose' its genomic termini and reduce its replication efficiency.

  3. Maintaining homeostasis by decision-making.

    Directory of Open Access Journals (Sweden)

    Christoph W Korn


    Full Text Available Living organisms need to maintain energetic homeostasis. For many species, this implies taking actions with delayed consequences. For example, humans may have to decide between foraging for high-calorie but hard-to-get, and low-calorie but easy-to-get food, under threat of starvation. Homeostatic principles prescribe decisions that maximize the probability of sustaining appropriate energy levels across the entire foraging trajectory. Here, predictions from biological principles contrast with predictions from economic decision-making models based on maximizing the utility of the endpoint outcome of a choice. To empirically arbitrate between the predictions of biological and economic models for individual human decision-making, we devised a virtual foraging task in which players chose repeatedly between two foraging environments, lost energy by the passage of time, and gained energy probabilistically according to the statistics of the environment they chose. Reaching zero energy was framed as starvation. We used the mathematics of random walks to derive endpoint outcome distributions of the choices. This also furnished equivalent lotteries, presented in a purely economic, casino-like frame, in which starvation corresponded to winning nothing. Bayesian model comparison showed that--in both the foraging and the casino frames--participants' choices depended jointly on the probability of starvation and the expected endpoint value of the outcome, but could not be explained by economic models based on combinations of statistical moments or on rank-dependent utility. This implies that under precisely defined constraints biological principles are better suited to explain human decision-making than economic models based on endpoint utility maximization.

  4. 44 CFR 321.3 - Maintaining the mobilization base. (United States)


    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Maintaining the mobilization..., DEPARTMENT OF HOMELAND SECURITY PREPAREDNESS MAINTENANCE OF THE MOBILIZATION BASE (DEPARTMENT OF DEFENSE, DEPARTMENT OF ENERGY, MARITIME ADMINISTRATION) § 321.3 Maintaining the mobilization base. (a) Facilities...

  5. 32 CFR 298.3 - Records maintained by DIS. (United States)


    ... 32 National Defense 2 2010-07-01 2010-07-01 false Records maintained by DIS. 298.3 Section 298.3... OF INFORMATION ACT PROGRAM DEFENSE INVESTIGATIVE SERVICE (DIS) FREEDOM OF INFORMATION ACT PROGRAM § 298.3 Records maintained by DIS. It is the policy of DIS to make publicly available all information...

  6. Patients with coronary artery disease – Maintaining planned lifestyle ...

    African Journals Online (AJOL)

    The purpose of this study was to describe how patients with coronary artery disease, who have had one or more cardiac interventions, were maintaining their planned lifestyle adaptations at four months after the intervention. Furthermore, the study aimed to develop guidelines to further assist patients in maintaining lifestyle ...

  7. A Methodology for Integrating Maintainability Using Software Metrics


    Lewis, John A.; Henry, Sallie M.


    Maintainability must be integrated into software early in the development process. But for practical use, the techniques used must be as unobtrusive to the existing software development process as possible. This paper defines a methodology for integrating maintainability into large-scale software and describes an experiment which implemented the methodology into a major commercial software development environment.

  8. 49 CFR 1310.2 - Requirement to maintain tariffs. (United States)


    ... HOUSEHOLD GOODS CARRIERS § 1310.2 Requirement to maintain tariffs. (a) Except when providing transportation... household goods only if the rates, and related rules and practices, for such transportation or service are...

  9. Developing maintainability for fusion power systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, H.S.; Mantz, H.C.; Curtis, C.T.; Buchheit, R.J.; Green, W.M.; Zuckerman, D.S.


    The overall purpose of the study is to identify design features of fusion power reactors which contribute to the achievement of high levels of maintainability. Previous phases evaluated several commercial tokamak reactor design concepts. This final phase compares the maintainability of a tandem mirror reactor (TMR) commercial conceptual design with the most maintainable tokamak concept selected from earlier work. A series of maintainability design guidelines and desirable TMR design features are defined. The effects of scheduled and unscheduled maintenance for most of the reactor subsystems are defined. The comparison of the TMR and tokamak reactor maintenance costs and availabilities show that both reactors have similar costs for scheduled maintenance at 19.4 and 20.8 million dollars annually and similar scheduled downtime availability impacts, achieving approximate availabilities of 79% at optimized maintenance intervals and cost of electricity.

  10. Reliability and maintainability data acquisition in equipment development tests

    Energy Technology Data Exchange (ETDEWEB)

    Haire, M.J.; Gift, E.H.


    The need for collection of reliability, maintainability, and availability data adds a new dimension to the data acquisition requirements of equipment development tests. This report describes the reliability and maintainability data that are considered necessary to ensure that sufficient and high quality data exist for a comprehensive, quantitative evaluation of equipment and system availability. These necessary data are presented as a set of data collection forms. Three data acquisition forms are discussed: an inventory and technical data form, which is filed by the design engineer when the design is finished or the equipment is received; an event report form, which is completed by the senior test operator at each shutdown; and a maintainability report, which is a collaborative effort between senior operators and lead engineers and is completed on restart. In addition, elements of a reliability, maintainability evaluation program are described. Emphasis is placed on the role of data, its storage, and use in such a program.

  11. A simple self-maintaining metabolic system: robustness, autocatalysis, bistability.

    Directory of Open Access Journals (Sweden)

    Gabriel Piedrafita

    Full Text Available A living organism must not only organize itself from within; it must also maintain its organization in the face of changes in its environment and degradation of its components. We show here that a simple (M,R-system consisting of three interlocking catalytic cycles, with every catalyst produced by the system itself, can both establish a non-trivial steady state and maintain this despite continuous loss of the catalysts by irreversible degradation. As long as at least one catalyst is present at a sufficient concentration in the initial state, the others can be produced and maintained. The system shows bistability, because if the amount of catalyst in the initial state is insufficient to reach the non-trivial steady state the system collapses to a trivial steady state in which all fluxes are zero. It is also robust, because if one catalyst is catastrophically lost when the system is in steady state it can recreate the same state. There are three elementary flux modes, but none of them is an enzyme-maintaining mode, the entire network being necessary to maintain the two catalysts.


    Directory of Open Access Journals (Sweden)

    Junaidi Mistar, Alfan Zuhairini


    Full Text Available The objectives of the present study are four-fold: (1 to identify the types of strategies to maintain proficiency used by teachers of English in Indonesia, (2 to know the intensity of use of the obtained strategy types, (3 to measure the inter-correlation in the use of the obtained strategy types, and (4 to investigate the effect of proficiency level on the use of maintaining strategies. The subjects were 93 teachers applying for S2 degree in 2010/2011 at the postgraduate program of the Islamic University of Malang. They were given two sets of instrument, a Likert-scale questionnaire of English proficiency maintaining strategies and a TOEFL test. Then, a factor analysis identified nine strategy categories, including language focusing, metacognitive and affective developing, reading and writing activating, language resource utilizing, cognitive processing, culture learning, social communicating, text analyzing, and radio listening strategies. These strategy types explained 63.84% of variances of maintaining strategies and they were used at high level of intensity. Moreover, the use of the nine strategy types were found to be inter-correlated with one another. Finally, no significant effect of proficiency level on strategy use was found, indicating that teachers with different level of proficiency reported using the same strategies of maintaining their proficiency.

  13. Functional analysis screening for problem behavior maintained by automatic reinforcement. (United States)

    Querim, Angie C; Iwata, Brian A; Roscoe, Eileen M; Schlichenmeyer, Kevin J; Ortega, Javier Virués; Hurl, Kylee E


    A common finding in previous research is that problem behavior maintained by automatic reinforcement continues to occur in the alone condition of a functional analysis (FA), whereas behavior maintained by social reinforcement typically is extinguished. Thus, the alone condition may represent an efficient screening procedure when maintenance by automatic reinforcement is suspected. We conducted a series of 5-min alone (or no-interaction) probes for 30 cases of problem behavior and compared initial predictions of maintenance or extinction to outcomes obtained in subsequent FAs. Results indicated that data from the screening procedure accurately predicted that problem behavior was maintained by automatic reinforcement in 21 of 22 cases and by social reinforcement in 7 of 8 cases. Thus, results of the screening accurately predicted the function of problem behavior (social vs. automatic reinforcement) in 28 of 30 cases. © Society for the Experimental Analysis of Behavior.

  14. Innovative scheduling to maintain clinical pharmacy services despite budget retrenchment. (United States)

    Siegel, J; Schneider, P J; Moore, T D


    A process is described in which staff scheduling was adjusted to maintain pharmaceutical services while achieving a 7% cutback in personnel costs. The pharmacy department in a 1000-bed university hospital was unable to achieve the necessary cost savings through reductions in sick leave and overtime hours. The pharmacy administration developed a plan that required pharmacists to work four 10-hour shifts per week and resulted in reduced hours of service. The pharmacists objected and proposed an alternative plan in which clinical service was maintained for 16 hours on weekdays and 12 hours on weekends. Pharmacist teams worked one flexible shift per week. Pharmacists developed an innovative staffing plan that allowed them to maintain a high level of practice and acceptable working hours.

  15. Validation Effectiveness of Develop Maintainability Allocation on Aircraft Mechanical Components

    Directory of Open Access Journals (Sweden)

    Wan Husain W.M.S.


    Full Text Available Maintainability Allocation is a process to identify the allowable maximum task time for each individual component. Consequently, this provides clear pictures to the designers to design and identify potential design improvement within allowable maintenance allocation time limits. During the design process elements such as missteps or misapplications most commonly occur. Here, the authors propose having the maximum target for each individual maintainability component. The main objective of this paper is to present the validation process of developed Maintainability Allocation to potentially eliminate previous problems. The process of validation begins with analysed all the data collected from Service Difficulty Reports (SDR for selected aircraft. This is to understand the problems from existing aircraft before a new design is proposed through the process of Maintainability Allocation prediction. The validation processes have discovered the importance of utilising historical information such as feedback information. The second area is looking at the element of quantifying the data collected from aircraft feedback information which contains various types of information that could be used for future improvement. Validation process shows that feedback information has helped to identify the critical and sensitive components that need more attention for further improvement. The study shows that the aircraft maintenance related feedback information systems analyses were very useful for deciding maintainability effectiveness; these include planning, organising maintenance and design improvement. There is no doubt that feedback information has the ability to contribute an important role in design activities. The results also show that maintainability is an important measure that can be used as a guideline for managing efforts made for the improvement of aircraft components.

  16. Maintaining realism in auditory length-perception experiments

    DEFF Research Database (Denmark)

    Kirkwood, Brent Christopher


    Humans are capable of hearing the lengths of wooden rods dropped onto hard floors. In an attempt to understand the influence of the stimulus presentation method for testing this kind of everyday listening task, listener performance was compared for three presentation methods in an auditory length......-estimation experiment. A comparison of the length-estimation accuracy for the three presentation methods indicates that the choice of presentation method is important for maintaining realism and for maintaining the acoustic cues utilized by listeners in perceiving length....

  17. Maintaining dignity. The perspective of nursing home residents

    DEFF Research Database (Denmark)

    Høy, Bente


    body image; feeling recognised and valued as a person of worth; Abilities and opportunities for changing of lifevalues; to exert control; to form and maintain meaningful relationships and to participation in meaningful activity. Conclusion. Although there is no one way to maintain dignity, the themes...... the perspective of the nursing home residents. Method. This qualitative study has an explorative design, based on qualitative individual research interviews. Twenty-eight nursing home residents were included from six nursing homes in Scandi-navia. A phenomenological-hermeneutic approach, inspired by Ricoeur...

  18. Maintaining Healthy Behaviors Following Weight Loss: A Grounded Theory Approach (United States)

    Zunker, Christie; Cox, Tiffany L.; Ard, Jamy D.; Ivankova, Nataliya V.; Rutt, Candace D.; Baskin, Monica L.


    This study explored the process of how women maintained their healthy behaviors after a weight management program using a grounded theory approach. We conducted 2 focus groups and 23 interviews with a purposeful sample of African American and Caucasian women aged 30 and older who lost greater than 5% of their body weight during a weight management…

  19. 41 CFR 51-4.3 - Maintaining qualification. (United States)


    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Maintaining qualification. 51-4.3 Section 51-4.3 Public Contracts and Property Management Other Provisions Relating to Public...) Furnish commodities or services in strict accordance with Government orders. (2) Comply with the...

  20. Maintaining and restoring sustainable ecosystems in southern Nevada [Chapter 7 (United States)

    Jeanne C. Chambers; Burton K. Pendleton; Donald W. Sada; Steven M. Ostoja; Matthew L. Brooks


    Managers in southern Nevada are challenged with determining appropriate goals and objectives and developing viable approaches for maintaining and restoring sustainable ecosystems in a time of rapid socio-ecological and environmental change. Sustainable or “healthy” ecosystems supply clean air, water and habitat for a diverse array of plants and animals. As described in...

  1. Maintaining genetic stability in a control flock of South African ...

    African Journals Online (AJOL)

    A genetic control flock of Merino sheep consisting of 160ewes and 16 rams, was established in 1969at the Tygerhoek ... It is concluded that genetic stability can be maintained in a. Merino control flock of this size under .... differences for individual traits (expressed as a percentage) also indicate that the replacement groups ...

  2. Maintaining Continuity of Knowledge of Spent Fuel Pools: Tool Survey

    Energy Technology Data Exchange (ETDEWEB)

    Benz, Jacob M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smartt, Heidi A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tanner, Jennifer E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); MacDougall, Matthew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    This report examines supplemental tools that can be used in addition to optical surveillance cameras to maintain CoK in low-to-no light conditions, and increase the efficiency and effectiveness of spent fuel CoK, including item counting and ID verification, in challenging conditions.

  3. Sourcing and maintaining a pool of suitably skilled interpreters for ...

    African Journals Online (AJOL)

    For a relatively small campus, given the low numbers of simultaneous interpreters generally available, establishing and maintaining an interpreting service of this magnitude posed a serious challenge. This article (in a case study format) describes, firstly, the recruitment and selection, and secondly, the training of a pool of ...

  4. Creating and maintaining chemical artificial life by robotic symbiosis

    DEFF Research Database (Denmark)

    Hanczyc, Martin M.; Parrilla, Juan M.; Nicholson, Arwen


    We present a robotic platform based on the open source RepRap 3D printer that can print and maintain chemical artificial life in the form of a dynamic, chemical droplet. The robot uses computer vision, a self-organizing map, and a learning program to automatically categorize the behavior...

  5. [Maintaining the proper distance for nurses working in the home]. (United States)

    Estève, Sonia


    Health professionals must be able to respond to many different situations which require technical knowledge and self-control. Particularly when working in the patient's home, nurses must know how to maintain a proper distance to protect themselves from burnout. In this respect, the practice analysis constitutes an adapted support tool. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Establishing and Maintaining Boundaries in Teacher-Student Relationships (United States)

    Bernstein-Yamashiro, Beth; Noam, Gil G.


    Because schools rarely provide guidelines for teachers that outline how they should conduct personal relationships with students, teachers must wrestle individually with how to establish, communicate, and maintain clear boundaries in their interactions. As schools work to become more personal environments, school administrators will need to help…

  7. Breaking the Sound Barrier: Starting and Maintaining an Audiobook Collection. (United States)

    Kaye, Sheldon; Baxter, Beth


    Discusses factors for libraries to consider when starting and maintaining an audiobook collection, including patron profiles; funding and budgeting; selection and ordering; listener preferences, including abridged versus unabridged titles; packaging and appearance; shelving and location; and future possibilities. A sidebar provides detailed…

  8. 30 CFR 870.22 - Maintaining required production records. (United States)


    ... INTERIOR ABANDONED MINE LAND RECLAMATION ABANDONED MINE RECLAMATION FUND-FEE COLLECTION AND COAL PRODUCTION REPORTING § 870.22 Maintaining required production records. (a) If you engage in or conduct a surface coal...: (1) The tons of coal you produced, bought, sold, or transferred, the amount of money you received per...

  9. Impact of Agile Software Development Model on Software Maintainability (United States)

    Gawali, Ajay R.


    Software maintenance and support costs account for up to 60% of the overall software life cycle cost and often burdens tightly budgeted information technology (IT) organizations. Agile software development approach delivers business value early, but implications on software maintainability are still unknown. The purpose of this quantitative study…

  10. Maintaining ecological soil functions - techniques in organic farming systems


    Beste, Andrea


    The ecological soil functions (e.g. habitat and living space, production and utilization, ecological regulation) have to be taken into account and maintained by farming systems. Organic farming systems can provide for this by using suitable crop rotations, manure management methods and tillage techniques.

  11. 34 CFR 668.163 - Maintaining and accounting for funds. (United States)


    ... 34 Education 3 2010-07-01 2010-07-01 false Maintaining and accounting for funds. 668.163 Section 668.163 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Cash Management § 668.163...

  12. A Platform for Developing and Maintaining Competences in PBL Supervision

    DEFF Research Database (Denmark)

    Huttel, Hans; Gnaur, Dorina


    One of the emerging challenges in academia is that of developing and maintaining teaching qualifications in a setting where teaching staff is often temporary and with diverse backgrounds. At Aalborg University, project-organized problem-based learning is at the heart of all degree programmes...

  13. Maintaining the ecological flows of estuaries: a critical reflection on ...

    African Journals Online (AJOL)

    Maintaining the ecological flows of estuaries: a critical reflection on the application and interpretation of the relevant legal framework through the lens of the Klein River Estuary. ... These estuaries provide numerous environmental goods and services to the species situated within and adjacent to them. In an effort to improve ...

  14. The potential role of agroforestry in maintaining soil fertility on ...

    African Journals Online (AJOL)

    Despite legislation curtailing their use, they are being used for grazing, and crop and vegetable production. The soils in the cultivated dambos suffer from major phosphorus and sulphur deficiencies and have low nitrogen and organic matter content. Organic fertilizers play a significant role in maintaining soil fertility on these ...

  15. 24 CFR 1003.505 - Records to be maintained. (United States)


    ... DEVELOPMENT COMMUNITY DEVELOPMENT BLOCK GRANTS FOR INDIAN TRIBES AND ALASKA NATIVE VILLAGES Grant... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Records to be maintained. 1003.505 Section 1003.505 Housing and Urban Development Regulations Relating to Housing and Urban Development...

  16. 399 Maintaining Discipline and Orderliness in Secondary Education ...

    African Journals Online (AJOL)



    Oct 17, 2010 ... maintaining discipline and order and that neither principals nor teachers differ in their Mean Rating ... principals, teachers and parents should be worthy models for the students and that government should ... noted that 20% of the adolescents experience serious psychological conflicts, which may result in ...

  17. Maintaining excellence in teaching of human anatomy: University of ...

    African Journals Online (AJOL)

    Experience in maintaining excellence in teaching of human anatomy is important in informing strategies to mitigate worldwide decline in the level of knowledge of human anatomy among medical students and qualifying doctors. Factors responsible for the decline include reduction in teaching time, inadequate teachers and ...

  18. Maintaining Excellence While Managing Transitions: Norman S. Weir Revisited (United States)

    Emmons, Christine L.; Baskerville, Ruth


    In a national education climate where change is the only constant, Norman S. Weir Elementary School has maintained and expanded the reform efforts that have resulted in striking academic achievement and improved school climate. Despite changes in administration and staffing, a highly professional and committed staff has continued the…

  19. Fertilization test performance using Arbacia punctulata maintained in static culture

    Energy Technology Data Exchange (ETDEWEB)

    Serbst, J.R. [Environmental Protection Agency, Narragansett, RI (United States). Environmental Research Lab.; Wright, L.; Sheehan, C.V.; Fitzpatrick, K. [Science Applications International Corp., Narragansett, RI (United States)


    The sea urchin fertilization test using the Atlantic urchin, Arbacia punctulata, is widely utilized in evaluating toxicity of receiving waters and effluents as part of the NPDES program. While this species is easily maintained in uncontaminated, flow-through seawater systems, laboratories without access to flowing seawater either obtain new urchins for each test or maintain populations in static cultures. This study was conducted to assess test success and reproducibility of fertilization tests conducted using urchins maintained in separate-sex, static, temperature-controlled aquaria containing filtered natural seawater. Test performance was evaluated by periodically conducting the standard sea urchin fertilization test (EPA 600/4-87-028) using a common reference toxicant, sodium dodecyl sulfate (SDS) Thirteen tests were conducted between September 1993 and May 1994 using one population of urchins, and five tests were conducted between June and December 1994 with a second population of urchins. Test success was 100% (control fertilization > 50%) with a control fertilization mean of 96.4% (S.D. = 3.3). There were no differences between mean EC{sub 50} values calculated for each set of tests (p < 0.05). The running mean value for toxicity was 7.1 mg/L (S.D. = 1.26) for 18 tests, with a CV of 17.7%, comparing favorably with values generated using urchins maintained in flowing seawater. The running mean value for toxicity in these tests was 2.4 mg/L (S.D. = 0.9) for 18 tests conducted between November 1987 and July 1989 (ASTM STP 1124). Data from all urchin tests were used to construct a control chart defining normal ranges for SDS toxicity. This study demonstrated that fertile, adult sea urchins can produce consistent toxicity responses with low variability while being maintained in static, temperature regulated culture facilities.

  20. Dicer maintains the identity and function of proprioceptive sensory neurons. (United States)

    O'Toole, Sean M; Ferrer, Monica M; Mekonnen, Jennifer; Zhang, Haihan; Shima, Yasuyuki; Ladle, David R; Nelson, Sacha B


    Neuronal cell identity is established during development and must be maintained throughout an animal's life (Fishell G, Heintz N. Neuron 80: 602-612, 2013). Transcription factors critical for establishing neuronal identity can be required for maintaining it (Deneris ES, Hobert O. Nat Neurosci 17: 899-907, 2014). Posttranscriptional regulation also plays an important role in neuronal differentiation (Bian S, Sun T. Mol Neurobiol 44: 359-373, 2011), but its role in maintaining cell identity is less established. To better understand how posttranscriptional regulation might contribute to cell identity, we examined the proprioceptive neurons in the dorsal root ganglion (DRG), a highly specialized sensory neuron class, with well-established properties that distinguish them from other neurons in the ganglion. By conditionally ablating Dicer in mice, using parvalbumin (Pvalb)-driven Cre recombinase, we impaired posttranscriptional regulation in the proprioceptive sensory neuron population. Knockout (KO) animals display a progressive form of ataxia at the beginning of the fourth postnatal week that is accompanied by a cell death within the DRG. Before cell loss, expression profiling shows a reduction of proprioceptor specific genes and an increased expression of nonproprioceptive genes normally enriched in other ganglion neurons. Furthermore, although central connections of these neurons are intact, the peripheral connections to the muscle are functionally impaired. Posttranscriptional regulation is therefore necessary to retain the transcriptional identity and support functional specialization of the proprioceptive sensory neurons. NEW & NOTEWORTHY We have demonstrated that selectively impairing Dicer in parvalbumin-positive neurons, which include the proprioceptors, triggers behavioral changes, a lack of muscle connectivity, and a loss of transcriptional identity as observed through RNA sequencing. These results suggest that Dicer and, most likely by extension, micro

  1. Dielectric properties of ligand-modified gold nanoparticles/SU-8 photopolymer based nanocomposites

    KAUST Repository

    Toor, Anju


    This article reports the enhanced dielectric properties of a photodefinable nanocomposite material containing sub–10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of dielectric permittivity and loss tangent on particle concentration and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

  2. Dielectric properties of ligand-modified gold nanoparticle/SU-8 photopolymer based nanocomposites (United States)

    Toor, Anju; So, Hongyun; Pisano, Albert P.


    This article reports the enhanced dielectric properties of a photodefinable polymer nanocomposite material containing sub-10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of the dielectric permittivity and loss tangent on the particle concentration, and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

  3. Temperature effects in Au piezoresistors integrated in SU-8 cantilever chips

    DEFF Research Database (Denmark)

    Johansson, Alicia; Hansen, Ole; Hales, Jan Harry


    to binding of biomolecules on the surface of the cantilever. Here we present the characterization of the chip with respect to temperature changes in the surrounding environment. Furthermore, self-heating of the piezoresistors due to the applied voltage over the resistors is investigated including...

  4. A Multimodal, SU-8 - Platinum - Polyimide Microelectrode Array for Chronic In Vivo Neurophysiology.

    Directory of Open Access Journals (Sweden)

    Gergely Márton

    Full Text Available Utilization of polymers as insulator and bulk materials of microelectrode arrays (MEAs makes the realization of flexible, biocompatible sensors possible, which are suitable for various neurophysiological experiments such as in vivo detection of local field potential changes on the surface of the neocortex or unit activities within the brain tissue. In this paper the microfabrication of a novel, all-flexible, polymer-based MEA is presented. The device consists of a three dimensional sensor configuration with an implantable depth electrode array and brain surface electrodes, allowing the recording of electrocorticographic (ECoG signals with laminar ones, simultaneously. In vivo recordings were performed in anesthetized rat brain to test the functionality of the device under both acute and chronic conditions. The ECoG electrodes recorded slow-wave thalamocortical oscillations, while the implanted component provided high quality depth recordings. The implants remained viable for detecting action potentials of individual neurons for at least 15 weeks.

  5. Application of Ultrasonic Waves on Maintaining Freshness of Tilapia Fillet

    Directory of Open Access Journals (Sweden)

    Ruddy Suwandi


    Full Text Available ish fillet is one of fisheries products that easily deteriorated; hence handling techniques are needed to maintain the freshness. Ultrasonic wave have been widely applied to some of food products for maintaining freshness through microbial inactivation, however the ultrasonic application to fisheries products has not been reported. The purpose of this study was to analyze the effect of ultrasonic wave on fish freshness. The stages of the study were sample preparation, sonication, freshness parameters examination and histology observation. Ultrasonic wave did not affectthe organoleptic value and the TVB, but affected the pH value and the TPC. The sample in which the TPC value was found significantly different, were further observed after 48 and 96 hours storage. The result showed that the TPC value of sonicated sample for 9 minutes was lower to that of without sonication. Histology analysis showed, however, sonication made the structure of muscle fiber less compact and deformation of myomer was found.

  6. Minimum energetic cost to maintain a target nonequilibrium state (United States)

    Horowitz, Jordan M.; Zhou, Kevin; England, Jeremy L.


    In the absence of external driving, a system exposed to thermal fluctuations will relax to equilibrium. However, the constant input of work makes it possible to counteract this relaxation and maintain the system in a nonequilibrium steady state. In this article, we use the stochastic thermodynamics of Markov jump processes to compute the minimum rate at which energy must be supplied and dissipated to maintain an arbitrary nonequilibrium distribution in a given energy landscape. This lower bound depends on two factors: the undriven probability current in the equilibrium state and the distance from thermal equilibrium of the target distribution. By showing the consequences of this result in a few simple examples, we suggest general implications for the required energetic costs of macromolecular repair and cytosolic protein localization.

  7. Polarization maintaining linear cavity Er-doped fiber femtosecond laser (United States)

    Jang, Heesuk; Jang, Yoon-Soo; Kim, Seungman; Lee, Keunwoo; Han, Seongheum; Kim, Young-Jin; Kim, Seung-Woo


    We present a polarization-maintaining (PM) type of Er-doped fiber linear oscillator designed to produce femtosecond laser pulses with high operational stability. Mode locking is activated using a semiconductor saturable absorber mirror (SESAM) attached to one end of the linear PM oscillator. To avoid heat damage, the SESAM is mounted on a copper-silicon-layered heat sink and connected to the linear oscillator through a fiber buffer dissipating the residual pump power. A long-term stability test is performed to prove that the proposed oscillator design maintains a soliton-mode single-pulse operation without breakdown of mode locking over a week period. With addition of an Er-doped fiber amplifier, the output power is raised to 180 mW with 60 fs pulse duration, from which an octave-spanning supercontinuum is produced.

  8. Mitotic Bookmarking: Maintaining the Stem Cell Identity during Mitosis. (United States)

    Huang, Xin; Wang, Jianlong


    In Cell Reports, Liu et al. (2017) investigate mechanisms for how pluripotent stem cells maintain their identity during cell division. They show that the histone mark H3K27ac and pluripotency transcription factors remain associated with mitotic chromatin in ESCs and during iPSC reprogramming, demonstrating the importance of mitotic bookmarking in pluripotency. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Reliability, Availability and Maintainability Design Practices Guide. Volume 2 (United States)


    Autovon Commercial(301) 765-1000 *H. J. Caruso , W. Silver, D. J. Cichetti, D. M. Kubilus; Proceedings,1979 Annual Reliability and Maintainability Symposiums...required. The paper describes the development of a nondestructive test proceiure based upon the use of gamma radiation. IRT initially tried a neutron beam...Mobile Sources: A Compendium of Radiographic Results;* NAEC-92-116 Synopsis: This report is a coupendimu of the results of neutron radiographic

  10. Teaching and Maintaining Ethical Behavior in a Professional Organization


    Brodhead, Matthew T.; Higbee, Thomas S.


    In addition to continuing education mandates by the Behavior Analyst Certification Board (BACB), behavior-analytic professional organizations may adopt systems that teach and maintain ethical behavior in its employees. Systems of ethical supervision and management may allow for an organization to customize training that prevents ethical misconduct by employees. These systems may also allow supervisors to identify ethical problems in their infancy, allowing the organization to mitigate concern...

  11. Controlling Force in Polarization-Maintaining Fiber Fused Biconical Tapering


    Wei Zhang; Weibin Rong; Lefeng Wang; Qing Zheng; Lining Sun


    Fused biconical tapering (FBT) is an important method of manufacturing polarization-maintaining fiber (PMF) couplers. However, the tension on the ends of the fibers can affect the performance of the coupler. In this paper, a computer-based method of controlling the drawing force was presented. The system includes a drawing mechanism, rotary position encoders, and a control circuit. A three-dimensional model of a permanent magnet and a coil is constructed, and the relationship among the coil c...

  12. Neural correlates of maintaining generated images in visual working memory. (United States)

    Ewerdwalbesloh, Julia A; Palva, Satu; Rösler, Frank; Khader, Patrick H


    How are images that have been assembled from their constituting elements maintained as a coherent representation in visual working memory (vWM)? Here, we compared two conditions of vWM maintenance that only differed in how vWM contents had been created. Participants maintained images that they either had to assemble from single features or that they had perceived as complete objects. Object complexity varied between two and four features. We analyzed electroencephalogram phase coupling as a measure of cortical connectivity in a time interval immediately before a probe stimulus appeared. We assumed that during this time both groups maintained essentially the same images, but that images constructed from their elements would require more neural coupling than images based on a complete percept. Increased coupling between frontal and parietal-to-occipital cortical sources was found for the maintenance of constructed in comparison to nonconstructed objects in the theta, alpha, beta, and gamma frequency bands. A similar pattern was found for an increase in vWM load (2 vs. 4 features) for nonconstructed objects. Under increased construction load (2 vs. 4 features for constructed images), the pattern was restricted to fronto-parietal couplings, suggesting that the fronto-parietal attention network is coping with the higher attentional demands involved in maintaining constructed images, but without increasing the communication with the occipital visual buffer in which the visual representations are assumed to be stored. We conclude from these findings that the maintenance of constructed images in vWM requires additional attentional processes to keep object elements together as a coherent representation. Hum Brain Mapp 37:4349-4362, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Human-Centered Technology for Maintainability: Workshop Proceedings (United States)


    pendent sut’svsiemis. kescarchi rc~ sutil - deiiv(-,c f i o the -,,elective-set paradigm suggest that Lhe, bra in lwa. an, impressive ability to pat~l dcd...process. Indeed, there are very few tools out in today’s market to aid system-level designers. Those available do not capture or analyze the...almost everyone is aware, have become defacto standards among both research institutions and the graphics workstation market . Lisp still maintains a

  14. Mosquito C-type lectins maintain gut microbiome homeostasis


    Pang, Xiaojing; Xiao, Xiaoping; Liu, Yang; Zhang, Rudian; Liu, Jianying; Liu, Qiyong; Wang, Penghua; Cheng, Gong


    The long-term evolutionary interaction between the host immune system and symbiotic bacteria determines their cooperative rather than antagonistic relationship. It is known that commensal bacteria have evolved a number of mechanisms to manipulate the mammalian host immune system and maintain homeostasis. However, the strategies employed by the microbiome to overcome host immune responses in invertebrates still remain to be understood. Here, we report that the gut microbiome in mosquitoes util...

  15. Predictors of maintained high-risk behaviors among impoverished women. (United States)

    Nyamathi, A M; Bennett, C; Leake, B


    The researchers sought to explore and describe the demographic, cognitive, psychosocial, and behavioral factors associated with the continued risky behavior of a convenience sample of homeless and drug-addicted women two to four weeks after they had completed an AIDS education program. The sample included 942 crack users and 767 women who had multiple sex partners. Analyses revealed that impoverished women who maintained multiple sexual partners were less likely to be in drug recovery programs than in homeless shelters. They were more likely to share needles and be involved sexually with male injection drug users compared with impoverished women who did not maintain multiple sexual partners. Persistent crack users were older than those who reported cessation of crack use, were more often African American, and were more likely to have sex partners who were injecting drug users. Women who demonstrated less improvement in depression and distress scores, concerns, use of affective coping, appraisal of threat, and social support were more likely to maintain crack use and multiple partners. The study's implications for the design of intervention programs aimed at risk reduction based on ethnicity are discussed. PMID:7480615

  16. Lactobacillus GG in inducing and maintaining remission of Crohn's disease

    Directory of Open Access Journals (Sweden)

    Vanderhoof Jon A


    Full Text Available Abstract Background Experimental studies have shown that luminal antigens are involved in chronic intestinal inflammatory disorders such as Crohn's disease and ulcerative colitis. Alteration of the intestinal microflora by antibiotic or probiotic therapy may induce and maintain remission. The aim of this randomized, placebo-controlled trial was to determine the effect of oral Lactobacillus GG (L. GG to induce or maintain medically induced remission. Methods Eleven patients with moderate to active Crohn's disease were enrolled in this trial to receive either L. GG (2 × 109 CFU/day or placebo for six months. All patients were started on a tapering steroid regime and received antibiotics for the week before the probiotic/placebo medication was initiated. The primary end point was sustained remission, defined as freedom from relapse at the 6 months follow-up visit. Relapse was defined as an increase in CDAI of >100 points. Results 5/11 patients finished the study, with 2 patients in each group in sustained remission. The median time to relapse was 16 ± 4 weeks in the L. GG group and 12 ± 4.3 weeks in the placebo group (p = 0.5. Conclusion In this study we could not demonstrate a benefit of L. GG in inducing or maintaining medically induced remission in CD.

  17. Maintaining life and health by natural selection of protein molecules. (United States)

    Pirlet, K; Arthur-Goettig, A


    A concept for a life and health-preserving principle is presented, with reference to evolutionary, medical, and biochemical observations. Life comprises two basic phenomena: it unfolds over longer periods at the population level, and is sustained for the duration of individual life spans. The evolution of life within populations by means of natural selection of individuals is central to Darwin's theory of evolution. An important component of maintaining individual life is proposed here to be the natural selection of molecular components-the proteins, a process of preferred removal of denatured and old, synonymous with the selection of younger, functional molecules. The proteins of the cell are committed to fulfilling all the tasks programmed by the genome while continuously maintaining all appropriate cellular functions, including protecting the DNA. Physiological and environmental influences accelerate the breakdown of aged protein molecules, driving this renewal process so that the cell can maintain its protein stock at high-performance levels. The principle of selection makes the incredible dynamics of continual protein turnover, and hence not only the preservation of life, but the maintenance of health in individual beings, comprehensible. Arguments are presented to counter the hypothesis that protein breakdown is a stochastic, random process governed by first-order kinetics. Copyright 1999 Academic Press.

  18. Maintaining Mobile Network Coverage Availability in Disturbance Scenarios

    Directory of Open Access Journals (Sweden)

    Joonas Säe


    Full Text Available Disturbance and disaster scenarios prevent the normal utilization of mobile networks. The aim of this study is to maintain the availability of cellular networks in disturbance scenarios. In order to extend the disaster time functionality, energy usage optimization is needed to maintain reasonable coverage and capacity. Simulations performed with different network layouts show the effects of choosing only a portion of evolved node B (eNB macrosites to operate at a time. Different sets of three to nine three-sectored eNB sites are selected to study how the network would perform with a limited number of eNB sites. Simulation results show how the mobile network availability duration can be sustained by selecting a set of eNB sites to operate at a time and still maintain a reasonable service level and availability in disturbance scenarios. An increase of 100% to 500% can be achieved in the duration of “backup coverage” in cellular networks with backup batteries when the percentage of active eNB sites is reduced down to 20%.

  19. Reliability, availability, and maintainability: a key issue for ELTs (United States)

    Ansorge, Wolfgang R.


    Hundreds of mirror segment, thousands of high precision actuators, highly complex mechanical, hydraulic, electrical and other technology subsystems, and extremely sophisticated control systems: an ELT system consists of millions of individual parts and components each of them may fail and lead to a partial or complete system breakdown. Component and system reliability does not only influence the acquisition costs of a product, it also defines the necessary maintenance work and the required logistic support. Taking the long operational life time of an ELT into account, reliability and maintainability are some of the main contributors to the system life cycle costs. Reliability and maintainability are key characteristics of any product and have to be designed into it from the early beginning; they can neither be tested into a product nor introduced by numerous maintenance activities. This presentation explains the interconnections between Reliability, Availability, Maintainability and Safety (RAMS) and outlines the necessary RAMS and Reliability Centered Maintenance (RCM) processes and activities during the entire life cycle of an ELT and an ELT instrument from the initial planning to the eventual disposal phase.

  20. Polymer-filled microcontainers for oral delivery loaded using supercritical impregnation

    DEFF Research Database (Denmark)

    Marizza, Paolo; Keller, Stephan Sylvest; Müllertz, Anette


    In the last years a large variety of drug delivery systems have been developed to improve bioavailability of therapeutics in oral administration. An increasing interest has arisen in reservoir-based microdevices designed for active ingredients like water insoluble compounds and fragile biomolecules....... Such microdevices are designed to protect the active ingredient against degradation and deactivation, and to allow cytoadhesion and unidirectional drug release. There are few works which optimize the drug loading step and often therapeutics are dosed in the microdevices through laborious and time consuming...... the high throughput fabrication of microdevices for oral drug delivery with a safe and solvent-free solution. © 2013 Published by Elsevier B.V....

  1. Corrosion-Activated Micro-Containers for Environmentally Friendly Corrosion Protective Coatings (United States)

    Li, Wenyan; Buhrow, J. W.; Zhang, X.; Johnsey, M. N.; Pearman, B. P.; Jolley, S. T.; Calle, L. M.


    This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry. The NASA Kennedy Space Centers Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods.Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The release of the inhibitors from the microparticles in basic solution was studied. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed.The inhibition efficacy of the inhibitors, incorporated directly and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

  2. Maintaining Students’ Involvement in a Math Lecture Using Countdown Timers

    Directory of Open Access Journals (Sweden)

    Ann Krizzel A. Aban


    Full Text Available Involving students in a lecture is an important but not an easy task that every lecturer must encourage. This task becomes even greater in a math class that is composed of eighty to a hundred sixty students. In 2007, the University of the Philippines Los Baños (UPLB started offering some of its basic math courses in lecture-recitation set-up. This shift and many other factors drove most math instructors of UPLB to widely use presentation software, such as the PowerPoint (PPT, to deliver their lectures. The non-stop use of these softwares, however, seems to have negative effects on the students when it comes to maintaining their involvement in a lecture discussion for they tend to be more passive spectators. On the other hand, adding countdown timers strategically on some parts of the discussion seems to lessen such negative effects. This study determined the effectiveness of using countdown timers in maintaining students’ involvement in a lecture of MATH 27 (Analytic Geometry and Calculus II, a course in UPLB commonly taken by sophomore students. Results show that the effectiveness of countdown timers, as perceived by the students, is independent to students’ genders and degree programs, but is dependent to the colleges where the students belong to. Also, some effects of countdown timers are significantly correlated to various data from students’ profiles. It was concluded in the study that the use of countdown timers is effective in maintaining student’s involvement in MATH 27 lectures and might also be useful in other math lecture classes

  3. A nanofibrous electrospun patch to maintain human mesenchymal cell stemness. (United States)

    Pandolfi, L; Furman, N Toledano; Wang, Xin; Lupo, C; Martinez, J O; Mohamed, M; Taraballi, F; Tasciotti, E


    Mesenchymal stem cells (MSCs) have been extensively investigated in regenerative medicine because of their crucial role in tissue healing. For these properties, they are widely tested in clinical trials, usually injected in cell suspension or in combination with tridimensional scaffolds. However, scaffolds can largely affect the fates of MSCs, inducing a progressive loss of functionality overtime. The ideal scaffold must delay MSCs differentiation until paracrine signals from the host induce their change. Herein, we proposed a nanostructured electrospun gelatin patch as an appropriate environment where human MSCs (hMSCs) can adhere, proliferate, and maintain their stemness. This patch exhibited characteristics of a non-linear elastic material and withstood degradation up to 4 weeks. As compared to culture and expansion in 2D, hMSCs on the patch showed a similar degree of proliferation and better maintained their progenitor properties, as assessed by their superior differentiation capacity towards typical mesenchymal lineages (i.e. osteogenic and chondrogenic). Furthermore, immunohistochemical analysis and longitudinal non-invasive imaging of inflammatory response revealed no sign of foreign body reaction for 3 weeks. In summary, our results demonstrated that our biocompatible patch favored the maintenance of undifferentiated hMSCs for up to 21 days and is an ideal candidate for tridimensional delivery of hMSCs. The present work reports a nanostructured patch gelatin-based able to maintain in vitro hMSCs stemness features. Moreover, hMSCs were able to differentiate toward osteo- and chondrogenic lineages once induces by differentiative media, confirming the ability of this patch to support stem cells for a potential in vivo application. These attractive properties together with the low inflammatory response in vivo make this patch a promising platform in regenerative medicine.

  4. Planning, Building, and Maintaining a Successful Musculoskeletal Service Line. (United States)

    Sayeed, Zain; El-Othmani, Mouhanad M; Anoushiravani, Afshin A; Chambers, Monique C; Saleh, Khaled J


    Within the past 3 decades, a recent trend in the growth of musculoskeletal service lines has been seen nationally. Orthopedics offers an appealing concourse for implementation of service-line care. Within this review, the authors address the components involved in planning and building a musculoskeletal service line. The authors also address methods by which orthopedic surgeons can maintain the efficacy of their service lines by examining how orthopedic surgeons can navigate their service line through recent advents in health care reform. Finally, the authors review successful examples of musculoskeletal service lines currently in practice within the orthopedic community. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Managers' duty to maintain good workplace communications skills. (United States)

    Timmins, Fiona


    Communication is a fundamental element of care at every level of nursing practice. It is important, therefore, for nurse managers to create environments that promote and encourage good communication, and help nurses to develop their communication skills formally and informally. This article discusses the effects of communication on the quality of care. It examines nurses' professional duty to maintain good communication skills and how managers can help them do this. It also discusses nurse managers' communication skills in the context of leadership style, conflict resolution and self-awareness. Finally, it considers the notion of shared governance as good practice.

  6. Prepare to protect: Operating and maintaining a tornado safe room. (United States)

    Herseth, Andrew; Goldsmith-Grinspoon, Jennifer; Scott, Pataya


    Operating and maintaining a tornado safe room can be critical to the effective continuity of business operations because a firm's most valuable asset is its people. This paper describes aspects of operations and maintenance (O&M) for existing tornado safe rooms as well as a few planning and design aspects that affect the ultimate operation of a safe room for situations where a safe room is planned, but not yet constructed. The information is based on several Federal Emergency Management Agency safe room publications that provide guidance on emergency management and operations, as well as the design and construction of tornado safe rooms.

  7. JWIG: Yet Another Framework for Maintainable and Secure Web Applications

    DEFF Research Database (Denmark)

    Møller, Anders; Schwarz, Mathias Romme


    Although numerous frameworks for web application programming have been developed in recent years, writing web applications remains a challenging task. Guided by a collection of classical design principles, we propose yet another framework. It is based on a simple but flexible server......-oriented architecture that coherently supports general aspects of modern web applications, including dynamic XML construction, session management, data persistence, caching, and authentication, but it also simplifies programming of server-push communication and integration of XHTML-based applications and XML-based web...... services.The resulting framework provides a novel foundation for developing maintainable and secure web applications....

  8. Starting and maintaining a hospital-based ostomy support group. (United States)

    Cross, Heidi Huddleston; Hottenstein, Patricia


    Ostomy surgery alters body image; this process can be distressing for patients, who must transition through a type of grieving process. Attending an ostomy support group provides an atmosphere of acceptance, a feeling of being able to cope, and mutual respect. The WOC nurse employed by an acute care facility is well positioned to facilitate such a group. Our clinical experiences strongly suggest that patients move more rapidly through the stages of grief to acceptance of the ostomy when they interact with others who have shared similar experiences. This article describes how one hospital started and maintains an ostomy support group, and gives suggestions for successful implementation of a support group.

  9. Maintaining Traceability in an Evolving Distributed Computing Environment (United States)

    Collier, I.; Wartel, R.


    The management of risk is fundamental to the operation of any distributed computing infrastructure. Identifying the cause of incidents is essential to prevent them from re-occurring. In addition, it is a goal to contain the impact of an incident while keeping services operational. For response to incidents to be acceptable this needs to be commensurate with the scale of the problem. The minimum level of traceability for distributed computing infrastructure usage is to be able to identify the source of all actions (executables, file transfers, pilot jobs, portal jobs, etc.) and the individual who initiated them. In addition, sufficiently fine-grained controls, such as blocking the originating user and monitoring to detect abnormal behaviour, are necessary for keeping services operational. It is essential to be able to understand the cause and to fix any problems before re-enabling access for the user. The aim is to be able to answer the basic questions who, what, where, and when concerning any incident. This requires retaining all relevant information, including timestamps and the digital identity of the user, sufficient to identify, for each service instance, and for every security event including at least the following: connect, authenticate, authorize (including identity changes) and disconnect. In traditional grid infrastructures (WLCG, EGI, OSG etc.) best practices and procedures for gathering and maintaining the information required to maintain traceability are well established. In particular, sites collect and store information required to ensure traceability of events at their sites. With the increased use of virtualisation and private and public clouds for HEP workloads established procedures, which are unable to see 'inside' running virtual machines no longer capture all the information required. Maintaining traceability will at least involve a shift of responsibility from sites to Virtual Organisations (VOs) bringing with it new requirements for their

  10. Coevolution Maintains Diversity in the Stochastic "Kill the Winner" Model (United States)

    Xue, Chi; Goldenfeld, Nigel


    The "kill the winner" hypothesis is an attempt to address the problem of diversity in biology. It argues that host-specific predators control the population of each prey, preventing a winner from emerging and thus maintaining the coexistence of all species in the system. We develop a stochastic model for the kill the winner paradigm and show that the stable coexistence state of the deterministic kill the winner model is destroyed by demographic stochasticity, through a cascade of extinction events. We formulate an individual-level stochastic model in which predator-prey coevolution promotes the high diversity of the ecosystem by generating a persistent population flux of species.

  11. The human brain maintains contradictory and redundant auditory sensory predictions.

    Directory of Open Access Journals (Sweden)

    Marika Pieszek

    Full Text Available Computational and experimental research has revealed that auditory sensory predictions are derived from regularities of the current environment by using internal generative models. However, so far, what has not been addressed is how the auditory system handles situations giving rise to redundant or even contradictory predictions derived from different sources of information. To this end, we measured error signals in the event-related brain potentials (ERPs in response to violations of auditory predictions. Sounds could be predicted on the basis of overall probability, i.e., one sound was presented frequently and another sound rarely. Furthermore, each sound was predicted by an informative visual cue. Participants' task was to use the cue and to discriminate the two sounds as fast as possible. Violations of the probability based prediction (i.e., a rare sound as well as violations of the visual-auditory prediction (i.e., an incongruent sound elicited error signals in the ERPs (Mismatch Negativity [MMN] and Incongruency Response [IR]. Particular error signals were observed even in case the overall probability and the visual symbol predicted different sounds. That is, the auditory system concurrently maintains and tests contradictory predictions. Moreover, if the same sound was predicted, we observed an additive error signal (scalp potential and primary current density equaling the sum of the specific error signals. Thus, the auditory system maintains and tolerates functionally independently represented redundant and contradictory predictions. We argue that the auditory system exploits all currently active regularities in order to optimally prepare for future events.

  12. How to keep punishment to maintain cooperation: Introducing social vaccine (United States)

    Yamamoto, Hitoshi; Okada, Isamu


    Although there is much support for the punishment system as a sophisticated approach to resolving social dilemmas, more than a few researchers have also pointed out the limitations of such an approach. Second-order free riding is a serious issue facing the punishment system. Various pioneering works have suggested that an anti-social behavior or noise stemming from a mutation may, surprisingly, be helpful for avoiding second-order freeloaders. In this work, we show through mathematical analysis and an agent-based simulation of a model extending the meta-norms game that the coercive introduction of a small number of non-cooperators can maintain a cooperative regime robustly. This paradoxical idea was inspired by the effect of a vaccine, which is a weakened pathogen injected into a human body to create antibodies and ward off infection by that pathogen. Our expectation is that the coercive introduction of a few defectors, i.e., a social vaccine, will help maintain a highly cooperative regime because it will ensure that the punishment system works.

  13. Sister chromosome pairing maintains heterozygosity in parthenogenetic lizards. (United States)

    Lutes, Aracely A; Neaves, William B; Baumann, Diana P; Wiegraebe, Winfried; Baumann, Peter


    Although bisexual reproduction has proven to be highly successful, parthenogenetic all-female populations occur frequently in certain taxa, including the whiptail lizards of the genus Aspidoscelis. Allozyme analysis revealed a high degree of fixed heterozygosity in these parthenogenetic species, supporting the view that they originated from hybridization events between related sexual species. It has remained unclear how the meiotic program is altered to produce diploid eggs while maintaining heterozygosity. Here we show that meiosis commences with twice the number of chromosomes in parthenogenetic versus sexual species, a mechanism that provides the basis for generating gametes with unreduced chromosome content without fundamental deviation from the classic meiotic program. Our observation of synaptonemal complexes and chiasmata demonstrate that a typical meiotic program occurs and that heterozygosity is not maintained by bypassing recombination. Instead, fluorescent in situ hybridization probes that distinguish between homologues reveal that bivalents form between sister chromosomes, the genetically identical products of the first of two premeiotic replication cycles. Sister chromosome pairing provides a mechanism for the maintenance of heterozygosity, which is critical for offsetting the reduced fitness associated with the lack of genetic diversity in parthenogenetic species.

  14. Experience of maintaining laboratory educational website′s sustainability

    Directory of Open Access Journals (Sweden)

    Izak B Dimenstein


    Full Text Available Laboratory methodology websites are specialized niche websites. The visibility of a niche website transforms it into an authority site on a particular "niche of knowledge." This article presents some ways in which a laboratory methodology website can maintain its sustainability. The optimal composition of the website includes a basic content, a blog, and an ancillary part. This article discusses experimenting with the search engine optimization query results page. Strategic placement of keywords and even phrases, as well as fragmentation of the post′s material, can improve the website′s visibility to search engines. Hyperlinks open a chain reaction of additional links and draw attention to the previous posts. Publications in printed periodicals are a substantial part of a niche website presence on the Internet. Although this article explores a laboratory website on the basis of our hands-on expertise maintaining "Grossing Technology in Surgical Pathology" ( website with a high volume of traffic for more than a decade, the recommendations presented here for developing an authority website can be applied to other professional specialized websites. The authority websites visibility and sustainability are preconditions for aggregating them in a specialized educational laboratory portal.

  15. Maintaining Aura's Orbit Requirements Under New Maneuver Operations (United States)

    Johnson, Megan; Petersen, Jeremy D.


    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Auras Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Auras frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under no-slew operations

  16. Maintaining families’ well-being in everyday life

    Directory of Open Access Journals (Sweden)

    Kristina Ziegert


    Full Text Available The aim of this paper is to discuss how everyday life changes for the family in the event of chronic illness or disability. It changes physically due to loss of body function and socially due to time and other constraints related to treatment or lack of mobility. Equally important, there is a psychological impact due to the uncertainty of the future. The article will explore how family participation can help to maintain well-being in everyday life. The family should therefore focus on their own needs as much as on the needs of the family members who are ill. In order to maintain well-being in everyday life, it is crucial for the family to create routines and spend time doing things that they enjoy. By doing this, the family will create a rhythm of well-being regardless of the critical family situation. Family members and professional caregivers also need to come together at the beginning and during the illness or disability event to discuss changes that could be made day-to-day for all those involved, thereby making for an easier transition into care giving.

  17. Maintaining operational excellence: building capability beyond knowledge transfer

    Energy Technology Data Exchange (ETDEWEB)

    Ramjist, S. [Ontario Power Generation, Darlington Nuclear Generating Station, Bowmanville, Ontario (Canada)


    This paper describes the issues relating to human resources and maintaining capabilities in an organization. The sustaining elements are: vision and plan for excellence; invest in the plant; invest in human capital; find and fix problems. There is much discussion about knowledge transfer and retention that is mainly focused on technical attributes and proficiency. We are losing more people with the requisite managerial and leadership capability than we can develop and backfill at a Time when our industry is facing increased competition and decreased margins. We are vulnerable because this Increases our dependence on augmented staff for certain key leadership roles. Previous methods for developing people will take too long and does not appeal to current generation. A solution, not the only solution, but the one we have chosen is initial hiring of operators, maintainers and engineers, internal promotion for key roles (FLM, FSOS, Shift Supervisor, Section Manager, ANO) and focus on all three aspects of capability and looking for leadership traits. Look for ambition, drive, initiative and motivation. Identify, separate and stream. Take specific measures to accelerate growth.

  18. Reliability, maintainability, and availability engineering for integrated community energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.Y.; Mavec, J.; Wolosewicz, R.M.; Calm, J.M.; Chopra, P.S.


    The reliability, maintainability, and availability (RMA) engineering methodologies for integrated community energy systems (ICES) are reported. Since the tangible and intangible costs of a system failure may outweigh the benefits of the ICES approaches, RMA consideration must be an integral part of ICES engineering. The effectiveness of system planning and design depends on component reliability information and on forecasts of community load profiles. Supply subsystems must provide sufficient capacity to meet demands in spite of maintenance and unscheduled outages. This allowance is the major task of probabilistic system planning. Because reliability and maintainability performance is partially a random process, probabilistic methodology is required for analysis and comparison. Portions of a community energy system being modified or expanded may already be in use before additional portions reach the design stage. This situation presents an opportunity to extend the RMA assessment of the existing system and to improve the additions that will be made to it. RMA engineering is essential to all phases of planning, design, construction, and operation of ICES. The methodologies presented provide a systematic, disciplined approach to predict and analyze RMA, to determine corrective actions necessary, and to achieve performance goals.

  19. Landscape irrigation management for maintaining an aquifer and economic returns. (United States)

    Kovacs, Kent Forrest; Mancini, Mattia; West, Grant


    Expanding irrigated agriculture and dryer climatic conditions has led to large-scale withdrawals of groundwater and the decline in shallow aquifers. Policy makers must wrestle with the challenge of maintaining economic growth while conserving the groundwater resource. A spatially explicit landscape level model analyzes consequences of optimally chosen crop mix patterns on an aquifer and economic returns. The model of the groundwater use incorporates irrigation needs of the crops grown, initial aquifer thickness, hydro-conductivity of the aquifer, and distance to surrounding grid cells. The economic model incorporates the site specific yield, crop mix, and irrigation practice investments to predict economic returns. A tradeoff occurs between the volume of the aquifer and economic returns due to groundwater withdrawal for irrigation, but the farm's ability to grow profitable lower irrigation crops dampens the intensity of this tradeoff. Allowing for multiple unconventional irrigation practices that are yield increasing and water conserving significantly increases the economic returns of a given crop mix while maintaining the aquifer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Maintaining dignity. The perspective of nursing home residents

    DEFF Research Database (Denmark)

    Høy, Bente


    Purpose. The overall purpose of this cross-country Nordic study was to gain further knowledge about dignity in nursing homes and the circumstances which may have an impact on it. The aim of this part of the study is to present the results, exploring nursing home residents’ experiences on how dign...... may be used as a frame-work to understand what nursing home residents tend to value and support dignity in the context of vulnerable situations in eldercare.......Purpose. The overall purpose of this cross-country Nordic study was to gain further knowledge about dignity in nursing homes and the circumstances which may have an impact on it. The aim of this part of the study is to present the results, exploring nursing home residents’ experiences on how...... dignity is maintained. Background. Elderly living in nursing homes are vulnerable which appeal to nursing care ethics and emphasise the importance of care for human dignity. There have been several attempts to define dignity as a theoretical concept, but few studies on how dignity is maintained from...

  1. Multiple Relationships : Maintaining Professional Identity in Rural Social Work Practice

    Directory of Open Access Journals (Sweden)

    Keith Brownlee


    Full Text Available Working in a rural community locates the professional in a wider social network as community members often expect more from their professionals; not only as service providers, but also as engaged members of the community. This can result in the rural social worker being highly visible both personally and professionally and it can also lead to overlapping relationships. These higher expectations can place stress on the worker in terms of maintaining accepted professional roles and a sense of professional identity. This qualitative study explores the first-hand experiences of a cross-section of service providers in more than a dozen communities within northwestern Ontario and northern Manitoba, Canada. The responses of the participants provide some insight into how rural practitioners maintain their professional identity when working within the unique demands of the rural and remote context. Recurring themes from the interviews suggest that these professionals craft their own informal decision-making processes to address intersecting roles, community gossip, and personal isolation, even while, in some cases, practicing in their home community. The findings provide greater understanding of the pressures and realities of working in small remote towns and the challenges of responding to the expectations and realities of relationships including the expectation of working with friends and family members of friends or colleagues: issues that have not been adequately studied in the literature to date.

  2. DNA Catenation Maintains Structure of Human Metaphase Chromosomes

    DEFF Research Database (Denmark)

    L. V. Bauer, David; Marie, Rodolphe; Rasmussen, Kristian Hagsted


    Mitotic chromosome structure is pivotal to cell division but difficult to observe in fine detail using conventional methods. DNA catenation has been implicated in both sister chromatid cohesion and chromosome condensation, but has never been observed directly. We have used a lab-on-a-chip microfl......Mitotic chromosome structure is pivotal to cell division but difficult to observe in fine detail using conventional methods. DNA catenation has been implicated in both sister chromatid cohesion and chromosome condensation, but has never been observed directly. We have used a lab......-on-a-chip microfluidic device and fluorescence microscopy, coupled with a simple image analysis pipeline, to digest chromosomal proteins and examine the structure of the remaining DNA, which maintains the canonical ‘X’ shape. By directly staining DNA, we observe that DNA catenation between sister chromatids (separated...... by fluid flow) is composed of distinct fibres of DNA concentrated at the centromeres. Disrupting the catenation of the chromosomes with Topoisomerase IIa significantly alters overall chromosome shape, suggesting that DNA catenation must be simultaneously maintained for correct chromosome condensation...

  3. Discriminant analysis of maintaining a vertical position in the water

    Directory of Open Access Journals (Sweden)

    Bratuša Zoran


    Full Text Available Water polo is the only sports game that takes place in the water. During the outplay, a vertical body position with the two basic mechanisms of the leg work - a breaststroke leg kick and an eggbeater leg kick, prevails. Starting from the significance of a vertical position during the game play, the methods of assessing physical preparedness of the athletes of all the categories also include the evaluation of maintaining a vertical position and consequently the load of the leg muscles. The measurements are performed during the maintenance of a vertical position (swimming in place through one of the specified mechanisms of leg work, i.e. a vertical position technique. The aim of this paper was to determine the application of different mechanisms of the leg kicks in maintaining a vertical position with young water polo players in relation to their position. The study included 29 selected junior water polo players (age_15.8 ± 0.8 years; BH_185.2 ± 5.3cm and BW_81.7 ± 7.7kg. The measurements were performed during the tests of swimming in place at the maximum intensity lasting 10 seconds, by the breaststroke and eggbeater leg kicks. The isometric tensiometry tests were used for the measurements. The results were analysed by the application of descriptive statistics, and the kinetic selection characteristic was defined by the application of discriminant analysis. Higher average values were achieved with the breaststroke leg kick technique Fmax, ImpF and RFD (avgFmaxLEGGBK =157.46±19.93N; avgImpF_LEGGBK =45.43±10.64Ns; avgRFD_LEGGBK=337.85±80.73N/s; avgFmaxLBKICK=227.18±49.17N; avgImpF_LBKICK=55.99±14.59Ns; avgRFD_LBKICK=545.47±159.15N/s. After discriminant analysis, the results have shown that the eggbeater leg kick is a selection technique, whereas the force - Fmax is a kinetic selection variable. Based on the obtained results and the analyses performed it may be concluded that a training factor dominant for maintaining a vertical position by

  4. Guide to Operating and Maintaining EnergySmart Schools

    Energy Technology Data Exchange (ETDEWEB)



    Through a commitment to high performance, school districts are discovering that smart energy choices can create lasting benefits for students, communities, and the environment. For example, an energy efficient school district with 4,000 students can save as much as $160,000 a year in energy costs. Over 10 years, those savings can reach $1.6 million, translating into the ability to hire more teachers, purchase more textbooks and computers, or invest in additional high performance facilities. Beyond these bottomline benefits, schools can better foster student health, decrease absenteeism, and serve as centers of community life. The U.S. Department of Energy's EnergySmart Schools Program promotes a 30 percent improvement in existing school energy use. It also encourages the building of new schools that exceed code (ASHRAE 90.11999) by 50 percent or more. The program provides resources like this Guide to Operating and Maintaining EnergySmart Schools to assist school decisionmakers in planning, financing, operating, and maintaining energy efficient, high performance schools. It also offers education and training for building industry professionals. Operations and maintenance refer to all scheduled and unscheduled actions for preventing equipment failure or decline with the goal of increasing efficiency, reliability, and safety. A preventative maintenance program is the organized and planned performance of maintenance activities in order to prevent system or production problems or failures from occurring. In contrast, deferred maintenance or reactive maintenance (also called diagnostic or corrective maintenance) is conducted to address an existing problem. This guide is a primary resource for developing and implementing a districtor schoolwide operations and maintenance (O&M) program that focuses on energy efficiency. The EnergySmart Schools Solutions companion CD contains additional supporting information for design, renovation, and retrofit projects. The objective

  5. Design and Application of the Exploration Maintainability Analysis Tool (United States)

    Stromgren, Chel; Terry, Michelle; Crillo, William; Goodliff, Kandyce; Maxwell, Andrew


    Conducting human exploration missions beyond Low Earth Orbit (LEO) will present unique challenges in the areas of supportability and maintainability. The durations of proposed missions can be relatively long and re-supply of logistics, including maintenance and repair items, will be limited or non-existent. In addition, mass and volume constraints in the transportation system will limit the total amount of logistics that can be flown along with the crew. These constraints will require that new strategies be developed with regards to how spacecraft systems are designed and maintained. NASA is currently developing Design Reference Missions (DRMs) as an initial step in defining future human missions. These DRMs establish destinations and concepts of operation for future missions, and begin to define technology and capability requirements. Because of the unique supportability challenges, historical supportability data and models are not directly applicable for establishing requirements for beyond LEO missions. However, supportability requirements could have a major impact on the development of the DRMs. The mass, volume, and crew resources required to support the mission could all be first order drivers in the design of missions, elements, and operations. Therefore, there is a need for enhanced analysis capabilities to more accurately establish mass, volume, and time requirements for supporting beyond LEO missions. Additionally, as new technologies and operations are proposed to reduce these requirements, it is necessary to have accurate tools to evaluate the efficacy of those approaches. In order to improve the analysis of supportability requirements for beyond LEO missions, the Space Missions Analysis Branch at the NASA Langley Research Center is developing the Exploration Maintainability Analysis Tool (EMAT). This tool is a probabilistic simulator that evaluates the need for repair and maintenance activities during space missions and the logistics and crew

  6. Patients with coronary artery disease – maintaining planned lifestyle adaptations

    Directory of Open Access Journals (Sweden)

    Wanda Jacobs


    Full Text Available The purpose of this study was to describe how patients with coronary artery disease, who have had one or more cardiac interventions, were maintaining their planned lifestyle adaptations at four months after the intervention. Furthermore, the study aimed to develop guidelines to further assist patients in maintaining lifestyle adaptations. A descriptive study was undertaken using the survey method. The population consisted of 65 participants (42 males, 23 females from five private hospitals in Gauteng. The questions for a questionnaire were derived from a conceptual framework. The participants first completed the questionnaire immediately before they were discharged, and again over the telephone four months after the intervention. Descriptive statistics were used to analyse the data obtained. The results showed that patients suffering from coronary artery disease do adapt their lifestyle after interventions, but most patients find it problematic to stop smoking. It is essential for patients with coronary artery disease to maintain lifestyle adaptations to ensure further health and prevention of recurrence of the same problems. These adaptations should be a lifelong commitment. Opsomming Die doel van die studie was om te beskryf hoe pasiënte met koronêre vatsiektes wat een of meer kardiale prosedures ondergaan het, die beplande verandering aan hulle lewenstyl op vier maande na die prosedures handhaaf. Verder het die studie gepoog om riglyne daar te stel wat pasiënte kan help om lewenstylaanpassings vol te hou. ’n Opnamemetode is gebruik om ’n beskrywende studie uit te voer. Die populasie het uit 65 deelnemers (42 mans en 23 vroue van vyf privaat hospitale in Gauteng bestaan. ’n Vraelys is vanuit ’n konseptuele raamwerk saamgestel. Die vraelys is net voor ontslag aan die deelnemers gegee om te voltooi, en weer telefonies vier maande na ontslag. Beskrywende statistiek is gebruik om die data te ontleed. Die resultate toon dat pasi

  7. Controlling Force in Polarization-Maintaining Fiber Fused Biconical Tapering

    Directory of Open Access Journals (Sweden)

    Wei Zhang


    Full Text Available Fused biconical tapering (FBT is an important method of manufacturing polarization-maintaining fiber (PMF couplers. However, the tension on the ends of the fibers can affect the performance of the coupler. In this paper, a computer-based method of controlling the drawing force was presented. The system includes a drawing mechanism, rotary position encoders, and a control circuit. A three-dimensional model of a permanent magnet and a coil is constructed, and the relationship among the coil current, rotation angle of the clamp, and electromagnetic force is determined using finite element simulations. Electromagnetic force control based on these simulations can be realized. The method is verified experimentally, and it is shown that a drawing force of 0–1.8 gf can be achieved with an error of within 3.04%. This result can be used in the FBT-based manufacture of fiber components such as fiber couplers and gratings.

  8. The role of lactobacilli and probiotics in maintaining vaginal health. (United States)

    Borges, Sandra; Silva, Joana; Teixeira, Paula


    The vaginal microbiota of healthy women consists typically of a diversity of anaerobic and aerobic microorganisms. Lactobacilli are the most prevalent and often numerically dominant microorganisms and are relevant as a barrier to infection. The capacity of lactobacilli to adhere and compete for adhesion sites in the vaginal epithelium and the capacity to produce antimicrobial compounds (hydrogen peroxide, lactic acid, bacteriocin-like substances), are important in the impairment of colonization by pathogens. This review summarizes the role of lactic acid bacteria in preventing illness of the host, including bacterial vaginosis, yeast vaginitis, urinary tract infection and sexually transmitted diseases. The administration of probiotics that colonize the vaginal tract can be important in maintaining a normal urogenital health and also to prevent or treat infections.

  9. Methods of achieving and maintaining an appropriate caesarean section rate.

    LENUS (Irish Health Repository)

    Robson, Michael


    Caesarean section rates continue to increase worldwide. The appropriate caesarean section rate remains a topic of debate among women and professionals. Evidence-based medicine has not provided an answer and depends on interpretation of the literature. Overall caesarean section rates are unhelpful, and caesarean section rates should not be judged in isolation from other outcomes and epidemiological characteristics. Better understanding of caesarean section rates, their consequences and their benefits will improve care, and enable learning between delivery units nationally and internationally. To achieve and maintain an appropriate caesarean section rate requires a Multidisciplinary Quality Assurance Programme in each delivery unit, recognising caesarean section rates as one of many factors that determine quality. Women will always choose the type of delivery that seems safest to them and their babies. Professionals need to monitor the quality of their practice continuously in a standardised way to ensure that women can make the right choice.

  10. Creating and maintaining chemical artificial life by robotic symbiosis. (United States)

    Hanczyc, Martin M; Parrilla, Juan M; Nicholson, Arwen; Yanev, Kliment; Stoy, Kasper


    We present a robotic platform based on the open source RepRap 3D printer that can print and maintain chemical artificial life in the form of a dynamic, chemical droplet. The robot uses computer vision, a self-organizing map, and a learning program to automatically categorize the behavior of the droplet that it creates. The robot can then use this categorization to autonomously detect the current state of the droplet and respond. The robot is programmed to visually track the droplet and either inject more chemical fuel to sustain a motile state or introduce a new chemical component that results in a state change (e.g., division). Coupling inexpensive open source hardware with sensing and feedback allows for replicable real-time manipulation and monitoring of nonequilibrium systems that would be otherwise tedious, expensive, and error-prone. This system is a first step towards the practical confluence of chemical, artificial intelligence, and robotic approaches to artificial life.

  11. Cell size control - a mechanism for maintaining fitness and function. (United States)

    Miettinen, Teemu P; Caldez, Matias J; Kaldis, Philipp; Björklund, Mikael


    The maintenance of cell size homeostasis has been studied for years in different cellular systems. With the focus on 'what regulates cell size', the question 'why cell size needs to be maintained' has been largely overlooked. Recent evidence indicates that animal cells exhibit nonlinear cell size dependent growth rates and mitochondrial metabolism, which are maximal in intermediate sized cells within each cell population. Increases in intracellular distances and changes in the relative cell surface area impose biophysical limitations on cells, which can explain why growth and metabolic rates are maximal in a specific cell size range. Consistently, aberrant increases in cell size, for example through polyploidy, are typically disadvantageous to cellular metabolism, fitness and functionality. Accordingly, cellular hypertrophy can potentially predispose to or worsen metabolic diseases. We propose that cell size control may have emerged as a guardian of cellular fitness and metabolic activity. © 2017 WILEY Periodicals, Inc.

  12. Rewarding peer reviewers: maintaining the integrity of science communication. (United States)

    Gasparyan, Armen Yuri; Gerasimov, Alexey N; Voronov, Alexander A; Kitas, George D


    This article overviews currently available options for rewarding peer reviewers. Rewards and incentives may help maintain the quality and integrity of scholarly publications. Publishers around the world implemented a variety of financial and nonfinancial mechanisms for incentivizing their best reviewers. None of these is proved effective on its own. A strategy of combined rewards and credits for the reviewers1 creative contributions seems a workable solution. Opening access to reviews and assigning publication credits to the best reviews is one of the latest achievements of digitization. Reviews, posted on academic networking platforms, such as Publons, add to the transparency of the whole system of peer review. Reviewer credits, properly counted and displayed on individual digital profiles, help distinguish the best contributors, invite them to review and offer responsible editorial posts.

  13. Method for rudder roll stabilization control by maintaining ship speed

    Directory of Open Access Journals (Sweden)

    LIU Zhiquan


    Full Text Available A ship navigating on the surface of the water may experience greater resistance, adversely affect-ing its speed and leading to energy loss. The added resistance of surface ships in both still water and waves are investigated, and the computation method of total speed loss is presented. An autopilot system is intro-duced to constrain the speed loss, and course keeping and rudder roll stabilization sliding mode control laws are proposed according to a compact control strategy. The two working conditions of "heading" and "heading plus anti-roll" are discussed, including roll stabilization, heading error, speed maintenance and rudder abrasion. The results show that the speed can be effectively maintained using this method, and from a commercial point of view, the fin-rudder roll stabilization control is not recommended for vessels equipped with both fins and rudders.

  14. Maintaining consistency between planning hierarchies: Techniques and applications (United States)

    Zoch, David R.


    In many planning and scheduling environments, it is desirable to be able to view and manipulate plans at different levels of abstraction, allowing the users the option of viewing and manipulating either a very detailed representation of the plan or a high-level more abstract version of the plan. Generating a detailed plan from a more abstract plan requires domain-specific planning/scheduling knowledge; the reverse process of generating a high-level plan from a detailed plan Reverse Plan Maintenance, or RPM) requires having the system remember the actions it took based on its domain-specific knowledge and its reasons for taking those actions. This reverse plan maintenance process is described as implemented in a specific planning and scheduling tool, The Mission Operations Planning Assistant (MOPA), as well as the applications of RPM to other planning and scheduling problems; emphasizing the knowledge that is needed to maintain the correspondence between the different hierarchical planning levels.

  15. Sociable mobile robots through self-maintained energy

    DEFF Research Database (Denmark)

    Ngo, Trung Dung; Schiøler, Henrik


    Research of sociable robots has emphasized interaction and coordination of mobile robots with inspiration from natural behavior of birds, insects, and fish: flocking, foraging, collecting, sharing and so forth. However, the animal behaviors are looking for food towards survival. In an animal...... society, collecting and sharing are experimentally recognized as the highest property. This paper issues an approach to sociable robots using self-maintained energy in robot society, which is naturally inspired from swarm behavior of honey-bee and ant. Typically, autonomous mobile robots are usually...... equipped with a finite energy, thus they can operate in a finite time. To overcome the limitation, we describe practical deployment of a group of mobile robot with the possibility of carrying and exchanging fuel, e.g. battery to other robots. Early implementation that includes modular hardware and control...

  16. The role of high technology in maintaining esthetic restorations. (United States)

    Goldstein, R E; Miller, M C


    Computer technology has revolutionized the way the world does business, allowing us to work faster, smarter, and more efficiently than ever before. Within dentistry, that translates to x-rays that use significantly smaller amounts of ionizing radiation, automated periodontal charting and storage devices, and imaging systems. Perhaps the greatest bottom-line benefit, especially in esthetic dentistry, is that these state-of-the-art developments enable dentists and hygienists to more effectively communicate with patients. The future of any restoration is based on the patient's motivation and ability to maintain an efficient oral hygiene routine. Esthetic restorations demand more vigorous home care programs to maximize their esthetic and functional life expectancy. With computerized images on screen, patients can better visualize the treatment that has been done and come to a realization that the restoration's success rests squarely on their shoulders.

  17. Creating and maintaining chemical artificial life by robotic symbiosis

    DEFF Research Database (Denmark)

    Hanczyc, Martin M.; Parrilla, Juan M.; Nicholson, Arwen


    of the droplet that it creates. The robot can then use this categorization to autonomously detect the current state of the droplet and respond. The robot is programmed to visually track the droplet and either inject more chemical fuel to sustain a motile state or introduce a new chemical component that results......We present a robotic platform based on the open source RepRap 3D printer that can print and maintain chemical artificial life in the form of a dynamic, chemical droplet. The robot uses computer vision, a self-organizing map, and a learning program to automatically categorize the behavior...... in a state change (e.g., division). Coupling inexpensive open source hardware with sensing and feedback allows for replicable real-time manipulation and monitoring of nonequilibrium systems that would be otherwise tedious, expensive, and error-prone. This system is a first step towards the practical...

  18. Creating and Maintaining Chemical Artificial Life by Robotic Symbiosis

    DEFF Research Database (Denmark)

    Hanczyc, Martin; Parrilla, Juan M.; Nicholson, Arwen


    of the droplet that it creates. The robot can then use this categorization to autonomously detect the current state of the droplet and respond. The robot is programmed to visually track the droplet and either inject more chemical fuel to sustain a motile state or introduce a new chemical component that results......We present a robotic platform based on the open source RepRap 3D printer that can print and maintain chemical artificial life in the form of a dynamic, chemical droplet. The robot uses computer vision, a self-organizing map, and a learning program to automatically categorize the behavior...... in a state change (e.g., division). Coupling inexpensive open source hardware with sensing and feedback allows for replicable real-time manipulation and monitoring of nonequilibrium systems that would be otherwise tedious, expensive, and error-prone. This system is a first step towards the practical...

  19. Gamma radiation combined with cinnamon oil to maintain fish quality (United States)

    Lyu, Fei; Zhang, Jing; Wei, Qianqian; Gao, Fei; Ding, Yuting; Liu, Shulai


    Effects of gamma radiation combined with cinnamon oil on quality of Northern Snakehead fish fillets were observed during storage at 4 °C. Fish fillets were treated with 1-5 kGy gamma radiation, 0.05-0.5% cinnamon oil or the combination of radiation and cinnamon oil. The antimicrobial activity increased with radiation dose and cinnamon oil concentration. During storage, the combination of 1 kGy radiation and 0.5% cinnamon oil displayed better inhibiting activities on aerobic plate counts, total volatile basic nitrogen, thiobarbituric acid reaction substances than 1 kGy radiation or 0.5% cinnamon oil used alone. Moreover, the combination could arrive at the similar inhibiting activities of cinnamon oil with higher concentration of 0.5% or radiation with higher dose of 5 kGy. Thus, the combination could decrease the radiation dose and cinnamon oil concentration without decreasing the effect of them on maintaining fish quality.

  20. [Maintaining residual renal function in patients on dialysis]. (United States)

    Ryckelynck, Jean-Philippe; Goffin, Éric; Verger, Christian


    There are evidences supporting a positive impact of renal residual function (RRF) on survival and quality of life of dialysis patients. Many strategies are available in clinical practices to maintain RRF. Hemodiafiltration seems to be better that conventional hemodialysis and similar to peritoneal dialysis. Arterial hypotension in hemodialysis or dehydration in peritoneal dialysis are deleterious in terms of preservation of RRF. Loop diuretics increase urine volume and natriuresis, not RRF. Radiocontrast and aminoglycosides may be used safely. The benefits of ACE inhibitors and angiotensin II receptor blockers are debated but have positive effect on blood pressure control and cardiac function. Neither biocompatible solutions nor the modality of peritoneal dialysis have demonstrated benefits on RRF. Copyright © 2013 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  1. DNA polymerase proofreading: Multiple roles maintain genome stability. (United States)

    Reha-Krantz, Linda J


    DNA polymerase proofreading is a spell-checking activity that enables DNA polymerases to remove newly made nucleotide incorporation errors from the primer terminus before further primer extension and also prevents translesion synthesis. DNA polymerase proofreading improves replication fidelity approximately 100-fold, which is required by many organisms to prevent unacceptably high, life threatening mutation loads. DNA polymerase proofreading has been studied by geneticists and biochemists for >35 years. A historical perspective and the basic features of DNA polymerase proofreading are described here, but the goal of this review is to present recent advances in the elucidation of the proofreading pathway and to describe roles of DNA polymerase proofreading beyond mismatch correction that are also important for maintaining genome stability. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  2. Reliability and Maintainability Data for Liquid Metal Cooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Cadwallader, Lee Charles [Idaho National Laboratory


    One of the coolants of interest for future fusion breeding blankets is lead-lithium. As a liquid metal it offers the advantages of high temperature operation for good station efficiency, low pressure, and moderate flow rate. This coolant is also under examination for use in test blanket modules to be used in the ITER international project. To perform reliability, availability, maintainability and inspectability (RAMI) assessment as well as probabilistic safety assessment (PSA) of lead-lithium cooling systems, component failure rate data are needed to quantify the system models. RAMI assessment also requires repair time data and inspection time data. This paper presents a new survey of the data sets that are available at present to support RAMI and PSA quantification. Recommendations are given for the best data values to use when quantifying system models.

  3. Maintaining Atmospheric Mass and Water Balance Within Reanalysis (United States)

    Takacs, Lawrence L.; Suarez, Max; Todling, Ricardo


    This report describes the modifications implemented into the Goddard Earth Observing System Version-5 (GEOS-5) Atmospheric Data Assimilation System (ADAS) to maintain global conservation of dry atmospheric mass as well as to preserve the model balance of globally integrated precipitation and surface evaporation during reanalysis. Section 1 begins with a review of these global quantities from four current reanalysis efforts. Section 2 introduces the modifications necessary to preserve these constraints within the atmospheric general circulation model (AGCM), the Gridpoint Statistical Interpolation (GSI) analysis procedure, and the Incremental Analysis Update (IAU) algorithm. Section 3 presents experiments quantifying the impact of the new procedure. Section 4 shows preliminary results from its use within the GMAO MERRA-2 Reanalysis project. Section 5 concludes with a summary.

  4. Mitochondria Maintain Distinct Ca2+Pools in Cone Photoreceptors. (United States)

    Giarmarco, Michelle M; Cleghorn, Whitney M; Sloat, Stephanie R; Hurley, James B; Brockerhoff, Susan E


    Ca 2+ ions have distinct roles in the outer segment, cell body, and synaptic terminal of photoreceptors. We tested the hypothesis that distinct Ca 2+ domains are maintained by Ca 2+ uptake into mitochondria. Serial block face scanning electron microscopy of zebrafish cones revealed that nearly 100 mitochondria cluster at the apical side of the inner segment, directly below the outer segment. The endoplasmic reticulum surrounds the basal and lateral surfaces of this cluster, but does not reach the apical surface or penetrate into the cluster. Using genetically encoded Ca 2+ sensors, we found that mitochondria take up Ca 2+ when it accumulates either in the cone cell body or outer segment. Blocking mitochondrial Ca 2+ uniporter activity compromises the ability of mitochondria to maintain distinct Ca 2+ domains. Together, our findings indicate that mitochondria can modulate subcellular functional specialization in photoreceptors. SIGNIFICANCE STATEMENT Ca 2+ homeostasis is essential for the survival and function of retinal photoreceptors. Separate pools of Ca 2+ regulate phototransduction in the outer segment, metabolism in the cell body, and neurotransmitter release at the synaptic terminal. We investigated the role of mitochondria in compartmentalization of Ca 2+ We found that mitochondria form a dense cluster that acts as a diffusion barrier between the outer segment and cell body. The cluster is surprisingly only partially surrounded by the endoplasmic reticulum, a key mediator of mitochondrial Ca 2+ uptake. Blocking the uptake of Ca 2+ by mitochondria causes redistribution of Ca 2+ throughout the cell. Our results show that mitochondrial Ca 2+ uptake in photoreceptors is complex and plays an essential role in normal function. Copyright © 2017 the authors 0270-6474/17/372061-12$15.00/0.

  5. Cost-effective solutions to maintaining smart grid reliability (United States)

    Qin, Qiu

    As the aging power systems are increasingly working closer to the capacity and thermal limits, maintaining an sufficient reliability has been of great concern to the government agency, utility companies and users. This dissertation focuses on improving the reliability of transmission and distribution systems. Based on the wide area measurements, multiple model algorithms are developed to diagnose transmission line three-phase short to ground faults in the presence of protection misoperations. The multiple model algorithms utilize the electric network dynamics to provide prompt and reliable diagnosis outcomes. Computational complexity of the diagnosis algorithm is reduced by using a two-step heuristic. The multiple model algorithm is incorporated into a hybrid simulation framework, which consist of both continuous state simulation and discrete event simulation, to study the operation of transmission systems. With hybrid simulation, line switching strategy for enhancing the tolerance to protection misoperations is studied based on the concept of security index, which involves the faulted mode probability and stability coverage. Local measurements are used to track the generator state and faulty mode probabilities are calculated in the multiple model algorithms. FACTS devices are considered as controllers for the transmission system. The placement of FACTS devices into power systems is investigated with a criterion of maintaining a prescribed level of control reconfigurability. Control reconfigurability measures the small signal combined controllability and observability of a power system with an additional requirement on fault tolerance. For the distribution systems, a hierarchical framework, including a high level recloser allocation scheme and a low level recloser placement scheme, is presented. The impacts of recloser placement on the reliability indices is analyzed. Evaluation of reliability indices in the placement process is carried out via discrete event

  6. The perceived relative worth of reaching and maintaining goal weight. (United States)

    O'Neil, P M; Smith, C F; Foster, G D; Anderson, D A


    To examine the perceived relative worth of reaching and maintaining a self-selected goal weight, for obese and non-obese individuals. Cross-sectional study. Twenty-five obese treatment-seekers (age 41.0 y, BMI 42.5) and a community sample of 31 obese (age 40.8 y, BMI 32.2) and 64 non-obese participants (age 32.4 y, BMI 23.4). An 18-item forced-choice questionnaire evaluating what participants would hypothetically sacrifice to reach and maintain their goal weight. Most obese treatment-seekers would hypothetically endure much to achieve their desired weight. For example, 88% or more would forego a job promotion, retiring with full-pay, eliminating the national debt, or winning their dream house or car or an all-expense-paid vacation, and smaller majorities would suffer loss of half their income or a job demotion. Many non-treatment-seeking obese would forfeit future rewards to reach goal weight, but fewer would incur negative events. About a third of non-obese participants would forgo certain positive events, but few would suffer an adverse event to achieve goal weight. Within the combined obese sample, females viewed attaining goal weight as more important than did males, but there were no significant racial differences. An index of overall worth of weight goal was related positively to current weight and BMI and negatively to goal weight as percentage of current weight (Prealistic weight goals, particularly but not exclusively by treatment-seeking and heavier obese people and those who desire greater weight loss. Clinicians should take this phenomenon into consideration, and public health initiatives should attempt to place body weight in a more balanced perspective.

  7. Professionals with hearing loss: maintaining that competitive edge. (United States)

    Tye-Murray, Nancy; Spry, Jacqueline L; Mauzé, Elizabeth


    The goals of this investigation were to gauge how hearing loss affects the self-perceived job performance and psycho-emotional status of professionals in the workforce and to develop a profile of their aural rehabilitation needs. Forty-eight participants who had at least a high school education and who hold salaried positions participated in one of seven focus groups. Participants first answered questions about a hypothetical executive who had hearing loss and considered how she might react to various communication issues. They then addressed questions about their own work-related predicaments. The sessions were audiovideo recorded and later transcribed for analysis. Unlike workers who have occupational hearing loss, the professionals in this investigation seem not to experience an inordinate degree of stigmatization in their workplaces, although most believe that hearing loss has negatively affected their job performance. Some of the participants believe that they have lost their "competitive edge," and some believe that they have been denied promotions because of hearing loss. However, most report that they have overcome their hearing-related difficulties by various means, and many have developed a determination and stamina to remain active in the workforce. The majority of the participants seemed to be unfamiliar with the Americans with Disability Act, Public Law 101-336. The overriding theme to emerge is that professionals desire to maintain their competency to perform their jobs and will do what they have to do to "get the job done." The situations of professionals who have hearing loss can be modeled, with a central theme of maintaining job competency or a competitive edge. It is hypothesized that five factors affect professionals' abilities to continue their optimal work performance in the face of hearing loss: (a) self-concept and sense of internal locus of control, (b) use of hearing assistive technology, (c) supervisor's and co-workers' perceptions and

  8. Maintaining consistent quality and clinical performance of biopharmaceuticals. (United States)

    Lamanna, William C; Holzmann, Johann; Cohen, Hillel P; Guo, Xinghua; Schweigler, Monika; Stangler, Thomas; Seidl, Andreas; Schiestl, Martin


    Biopharmaceuticals are large protein based drugs which are heterogeneous by nature due to post translational modifications resulting from cellular production, processing and storage. Changes in the abundance of different variants over time are inherent to biopharmaceuticals due to their sensitivity to subtle process differences and the necessity for regular manufacturing changes. Product variability must thus be carefully controlled to ensure that it does not result in changes in safety or efficacy. Areas covered: The focus of this manuscript is to provide improved understanding of the science and strategies used to maintain the quality and clinical performance of biopharmaceuticals, including biosimilars, throughout their lifecycle. This review summarizes rare historical instances where clinically relevant changes have occurred, defined here as clinical drift, and discusses modern tools used to prevent such changes, including improved analytics, quality systems and regulatory frameworks. Expert opinion: Despite their size complexity and heterogeneity, modern analytics, manufacturing quality systems and comparability requirements for the evaluation of manufacturing changes cumulatively help to ensure the consistent quality and clinical performance of biopharmaceuticals throughout their product lifecycle. Physicians and patients can expect the same safety and efficacy from biopharmaceuticals and their respective biosimilars irrespective of batch or production history.

  9. Endothelial C-type natriuretic peptide maintains vascular homeostasis. (United States)

    Moyes, Amie J; Khambata, Rayomand S; Villar, Inmaculada; Bubb, Kristen J; Baliga, Reshma S; Lumsden, Natalie G; Xiao, Fang; Gane, Paul J; Rebstock, Anne-Sophie; Worthington, Roberta J; Simone, Michela I; Mota, Filipa; Rivilla, Fernando; Vallejo, Susana; Peiró, Concepción; Sánchez Ferrer, Carlos F; Djordjevic, Snezana; Caulfield, Mark J; MacAllister, Raymond J; Selwood, David L; Ahluwalia, Amrita; Hobbs, Adrian J


    The endothelium plays a fundamental role in maintaining vascular homeostasis by releasing factors that regulate local blood flow, systemic blood pressure, and the reactivity of leukocytes and platelets. Accordingly, endothelial dysfunction underpins many cardiovascular diseases, including hypertension, myocardial infarction, and stroke. Herein, we evaluated mice with endothelial-specific deletion of Nppc, which encodes C-type natriuretic peptide (CNP), and determined that this mediator is essential for multiple aspects of vascular regulation. Specifically, disruption of CNP leads to endothelial dysfunction, hypertension, atherogenesis, and aneurysm. Moreover, we identified natriuretic peptide receptor-C (NPR-C) as the cognate receptor that primarily underlies CNP-dependent vasoprotective functions and developed small-molecule NPR-C agonists to target this pathway. Administration of NPR-C agonists promotes a vasorelaxation of isolated resistance arteries and a reduction in blood pressure in wild-type animals that is diminished in mice lacking NPR-C. This work provides a mechanistic explanation for genome-wide association studies that have linked the NPR-C (Npr3) locus with hypertension by demonstrating the importance of CNP/NPR-C signaling in preserving vascular homoeostasis. Furthermore, these results suggest that the CNP/NPR-C pathway has potential as a disease-modifying therapeutic target for cardiovascular disorders.

  10. Lifelong bilingualism maintains neural efficiency for cognitive control in aging. (United States)

    Gold, Brian T; Kim, Chobok; Johnson, Nathan F; Kryscio, Richard J; Smith, Charles D


    Recent behavioral data have shown that lifelong bilingualism can maintain youthful cognitive control abilities in aging. Here, we provide the first direct evidence of a neural basis for the bilingual cognitive control boost in aging. Two experiments were conducted, using a perceptual task-switching paradigm, including a total of 110 participants. In Experiment 1, older adult bilinguals showed better perceptual switching performance than their monolingual peers. In Experiment 2, younger and older adult monolinguals and bilinguals completed the same perceptual task-switching experiment while functional magnetic resonance imaging (fMRI) was performed. Typical age-related performance reductions and fMRI activation increases were observed. However, like younger adults, bilingual older adults outperformed their monolingual peers while displaying decreased activation in left lateral frontal cortex and cingulate cortex. Critically, this attenuation of age-related over-recruitment associated with bilingualism was directly correlated with better task-switching performance. In addition, the lower blood oxygenation level-dependent response in frontal regions accounted for 82% of the variance in the bilingual task-switching reaction time advantage. These results suggest that lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes.

  11. Distinct interactions select and maintain a specific cell fate. (United States)

    Doncic, Andreas; Falleur-Fettig, Melody; Skotheim, Jan M


    The ability to specify and maintain discrete cell fates is essential for development. However, the dynamics underlying selection and stability of distinct cell types remain poorly understood. Here, we provide a quantitative single-cell analysis of commitment dynamics during the mating-mitosis switch in budding yeast. Commitment to division corresponds precisely to activating the G1 cyclin positive feedback loop in competition with the cyclin inhibitor Far1. Cyclin-dependent phosphorylation and inhibition of the mating pathway scaffold Ste5 are required to ensure exclusive expression of the mitotic transcriptional program after cell cycle commitment. Failure to commit exclusively results in coexpression of both cell cycle and pheromone-induced genes, and a morphologically mixed inviable cell fate. Thus, specification and maintenance of a cellular state are performed by distinct interactions, which are likely a consequence of disparate reaction rates and may be a general feature of the interlinked regulatory networks responsible for selecting cell fates. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. SHOOT GROWTH1 maintains Arabidopsis epigenomes by regulating IBM1.

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    Vincent Coustham

    Full Text Available Maintaining correct DNA and histone methylation patterns is essential for the development of all eukaryotes. In Arabidopsis, we identified SHOOT GROWTH1 (SG1, a novel protein involved in the control of gene methylation. SG1 contains both a Bromo-Adjacent Homology (BAH domain found in several chromatin regulators and an RNA-Recognition Motif (RRM. The sg1 mutations are associated with drastic pleiotropic phenotypes. The mutants degenerate after few generations and are similar to mutants of the histone demethylase INCREASE IN BONSAI METHYLATION1 (IBM1. A methylome analysis of sg1 mutants revealed a large number of gene bodies hypermethylated in the cytosine CHG context, associated with an increase in di-methylation of lysine 9 on histone H3 tail (H3K9me2, an epigenetic mark normally found in silenced transposons. The sg1 phenotype is suppressed by mutations in genes encoding the DNA methyltransferase CHROMOMETHYLASE3 (CMT3 or the histone methyltransferase KRYPTONITE (KYP, indicating that SG1 functions antagonistically to CMT3 or KYP. We further show that the IBM1 transcript is not correctly processed in sg1, and that the functional IBM1 transcript complements sg1. Altogether, our results suggest a function for SG1 in the maintenance of genome integrity by regulating IBM1.

  13. SHOOT GROWTH1 maintains Arabidopsis epigenomes by regulating IBM1. (United States)

    Coustham, Vincent; Vlad, Daniela; Deremetz, Aurélie; Gy, Isabelle; Cubillos, Francisco A; Kerdaffrec, Envel; Loudet, Olivier; Bouché, Nicolas


    Maintaining correct DNA and histone methylation patterns is essential for the development of all eukaryotes. In Arabidopsis, we identified SHOOT GROWTH1 (SG1), a novel protein involved in the control of gene methylation. SG1 contains both a Bromo-Adjacent Homology (BAH) domain found in several chromatin regulators and an RNA-Recognition Motif (RRM). The sg1 mutations are associated with drastic pleiotropic phenotypes. The mutants degenerate after few generations and are similar to mutants of the histone demethylase INCREASE IN BONSAI METHYLATION1 (IBM1). A methylome analysis of sg1 mutants revealed a large number of gene bodies hypermethylated in the cytosine CHG context, associated with an increase in di-methylation of lysine 9 on histone H3 tail (H3K9me2), an epigenetic mark normally found in silenced transposons. The sg1 phenotype is suppressed by mutations in genes encoding the DNA methyltransferase CHROMOMETHYLASE3 (CMT3) or the histone methyltransferase KRYPTONITE (KYP), indicating that SG1 functions antagonistically to CMT3 or KYP. We further show that the IBM1 transcript is not correctly processed in sg1, and that the functional IBM1 transcript complements sg1. Altogether, our results suggest a function for SG1 in the maintenance of genome integrity by regulating IBM1.

  14. Maintaining the will to live of patients with advanced cancer. (United States)

    Khan, Luluel; Wong, Rebecca; Li, Madeline; Zimmermann, Camilla; Lo, Chris; Gagliese, Lucia; Rodin, Gary


    The will to live is a natural instinct experienced by all human beings. It tends to persist in humans, despite marked adversity such as that associated with advanced cancer. The will to live may be measured directly, or indirectly, by assessing the desire for hastened death. Factors that may affect it include age, life stage, and physical and psychological distress. In particular, states of depression and hopelessness may precede the loss of the will to live. Other psychosocial variables that may affect the will to live include physical suffering, attachment security, self-esteem, and spiritual well-being. A number of screening tools are available to identify risk factors for the loss of the will to live. Awareness of these factors can guide interventions to preserve morale and maintain hope in patients faced with a terminal illness. Critical among these are the alleviation of physical and psychosocial distress and the establishment of a therapeutic alliance that is sensitive to the specific support needs of individual patients. Comfort and facility with such supportive interventions in oncology will require greater attention to the development of communication and relationship skills at both undergraduate and postgraduate levels of training.

  15. Mitostasis in Neurons: Maintaining Mitochondria in an Extended Cellular Architecture. (United States)

    Misgeld, Thomas; Schwarz, Thomas L


    Neurons have more extended and complex shapes than other cells and consequently face a greater challenge in distributing and maintaining mitochondria throughout their arbors. Neurons can last a lifetime, but proteins turn over rapidly. Mitochondria, therefore, need constant rejuvenation no matter how far they are from the soma. Axonal transport of mitochondria and mitochondrial fission and fusion contribute to this rejuvenation, but local protein synthesis is also likely. Maintenance of a healthy mitochondrial population also requires the clearance of damaged proteins and organelles. This involves degradation of individual proteins, sequestration in mitochondria-derived vesicles, organelle degradation by mitophagy and macroautophagy, and in some cases transfer to glial cells. Both long-range transport and local processing are thus at work in achieving neuronal mitostasis-the maintenance of an appropriately distributed pool of healthy mitochondria for the duration of a neuron's life. Accordingly, defects in the processes that support mitostasis are significant contributors to neurodegenerative disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Role of SUPERMAN in maintaining Arabidopsis floral whorl boundaries. (United States)

    Sakai, H; Medrano, L J; Meyerowitz, E M


    The Arabidopsis gene SUPERMAN (SUP) is necessary for the proper spatial development of reproductive floral tissues. Recessive mutations cause extra stamens to form interior to the normal third whorl stamens, at the expense of fourth whorl carpel development. The mutant phenotype is associated with the ectopic expression of the B function genes, AP3 and PI, in the altered floral region, closer to the centre of the flower than in the wild type, and ap3 sup and pi sup double mutants exhibit a phenotype similar to ap3 and pi single mutants. These findings led to SUP being interpreted as an upstream negative regulator of the B function organ-identity genes, acting in the fourth whorl, to establish a boundary between stamen and carpel whorls. Here we show, using molecular cloning and analysis, that it is expressed in the third whorl and acts to maintain this boundary in developing flowers. The putative SUPERMAN protein contains one zinc-finger and a region resembling a basic leucine zipper motif, suggesting a function in transcriptional regulation.

  17. Can academic departments maintain industry relationships while promoting physician professionalism? (United States)

    Dubovsky, Steven L; Kaye, David L; Pristach, Cynthia A; DelRegno, Paula; Pessar, Linda; Stiles, Keith


    The authors describe the development of a comprehensive policy for relationships of full-time and volunteer faculty and residents with industry. The underlying philosophy was that an academic approach to relations with industry that emphasizes objective outcomes and internal change will be more effective than rote restrictions on behavior that assume that physicians cannot learn new behaviors and that are impossible to enforce. The policy, developed through much discussion and debate with stakeholders, involves elimination of industry-supplied meals, gifts, and favors; integration of industry-sponsored and academic research; education of faculty and residents about the ways in which industry marketing influences clinical decision making; and comprehensive disclosure by faculty, including to patients, of financial interests in industry. At occasional points in the psychopharmacology curriculum and at a departmental "pharma symposium," industry representatives or industry-sponsored guest speakers are allowed to present peer-reviewed articles followed by comments by a faculty member with relevant expertise about aspects of the presentation that are accurate or misleading and by a general discussion of research and clinical implications of the research and the manner in which it is presented. Adherence to new protocols has been high because faculty and residents participated in developing them and are involved in their implementation. Acceptance by industry representatives has been variable. Experience with this approach suggests that it is possible to develop a collaborative relationship with industry that maintains appropriate boundaries between industry and academia.

  18. MOF maintains transcriptional programs regulating cellular stress response. (United States)

    Sheikh, B N; Bechtel-Walz, W; Lucci, J; Karpiuk, O; Hild, I; Hartleben, B; Vornweg, J; Helmstädter, M; Sahyoun, A H; Bhardwaj, V; Stehle, T; Diehl, S; Kretz, O; Voss, A K; Thomas, T; Manke, T; Huber, T B; Akhtar, A


    MOF (MYST1, KAT8) is the major H4K16 lysine acetyltransferase (KAT) in Drosophila and mammals and is essential for embryonic development. However, little is known regarding the role of MOF in specific cell lineages. Here we analyze the differential role of MOF in proliferating and terminally differentiated tissues at steady state and under stress conditions. In proliferating cells, MOF directly binds and maintains the expression of genes required for cell cycle progression. In contrast, MOF is dispensable for terminally differentiated, postmitotic glomerular podocytes under physiological conditions. However, in response to injury, MOF is absolutely critical for podocyte maintenance in vivo. Consistently, we detect defective nuclear, endoplasmic reticulum and Golgi structures, as well as presence of multivesicular bodies in vivo in podocytes lacking Mof following injury. Undertaking genome-wide expression analysis of podocytes, we uncover several MOF-regulated pathways required for stress response. We find that MOF, along with the members of the non-specific lethal but not the male-specific lethal complex, directly binds to genes encoding the lysosome, endocytosis and vacuole pathways, which are known regulators of podocyte maintenance. Thus, our work identifies MOF as a key regulator of cellular stress response in glomerular podocytes.

  19. Fundamental Molecules and Mechanisms for Forming and Maintaining Neuromuscular Synapses

    Directory of Open Access Journals (Sweden)

    Steven J. Burden


    Full Text Available The neuromuscular synapse is a relatively large synapse with hundreds of active zones in presynaptic motor nerve terminals and more than ten million acetylcholine receptors (AChRs in the postsynaptic membrane. The enrichment of proteins in presynaptic and postsynaptic membranes ensures a rapid, robust, and reliable synaptic transmission. Over fifty years ago, classic studies of the neuromuscular synapse led to a comprehensive understanding of how a synapse looks and works, but these landmark studies did not reveal the molecular mechanisms responsible for building and maintaining a synapse. During the past two-dozen years, the critical molecular players, responsible for assembling the specialized postsynaptic membrane and regulating nerve terminal differentiation, have begun to be identified and their mechanism of action better understood. Here, we describe and discuss five of these key molecular players, paying heed to their discovery as well as describing their currently understood mechanisms of action. In addition, we discuss the important gaps that remain to better understand how these proteins act to control synaptic differentiation and maintenance.

  20. Dcf1 regulates neuropeptide expression and maintains energy balance. (United States)

    Liu, Qiang; Chen, Yu; Li, Qian; Wu, Liang; Wen, Tieqiao


    Neuropeptide Y (NPY) is an important neurotransmitter in the brain that plays a pivotal role in food intake and energy storage. Although many studies have focused on these functions, the regulation of NPY expression remains unclear. Here we showed that dendritic cell factor 1 (Dcf1) regulates NPY expression and maintains energy balance. We found that NPY expression is significantly reduced in the hypothalamus of Dcf1 knockout (Dcf1-/-, KO) mice. In contrast, Dcf1 overexpression significantly increases NPY expression in the cell line. We also found that Dcf1 acts upstream of the NPY gene to regulate NPY expression and modulates the NPY-NPY receptor 1-GABA signal. Notably, we observed a significant increase in the ATP concentration in Dcf1-/- mice, suggesting a greater demand for energy in the absence of Dcf1. We studied the relationship between Dcf1 and NPY and revealed that Dcf1 plays a critical role in energy balance. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Dangerous Animals Capture and Maintain Attention in Humans

    Directory of Open Access Journals (Sweden)

    Jessica L. Yorzinski


    Full Text Available Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions. We recorded the eye movements of participants as they detected images of a dangerous animal (target among arrays of nondangerous animals (distractors as well as detected images of a nondangerous animal (target among arrays of dangerous animals (distractors. We found that participants were quicker to locate targets when the targets were dangerous animals compared with nondangerous animals, even when spatial frequency and luminance were controlled. The participants were slower to locate nondangerous targets because they spent more time looking at dangerous distractors, a process known as delayed disengagement, and looked at a larger number of dangerous distractors. These results indicate that dangerous animals capture and maintain attention in humans, suggesting that historical predation has shaped some facets of visual orienting and its underlying neural architecture in modern humans.

  2. Dangerous animals capture and maintain attention in humans. (United States)

    Yorzinski, Jessica L; Penkunas, Michael J; Platt, Michael L; Coss, Richard G


    Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions). We recorded the eye movements of participants as they detected images of a dangerous animal (target) among arrays of nondangerous animals (distractors) as well as detected images of a nondangerous animal (target) among arrays of dangerous animals (distractors). We found that participants were quicker to locate targets when the targets were dangerous animals compared with nondangerous animals, even when spatial frequency and luminance were controlled. The participants were slower to locate nondangerous targets because they spent more time looking at dangerous distractors, a process known as delayed disengagement, and looked at a larger number of dangerous distractors. These results indicate that dangerous animals capture and maintain attention in humans, suggesting that historical predation has shaped some facets of visual orienting and its underlying neural architecture in modern humans.

  3. Splicing regulator SLU7 is essential for maintaining liver homeostasis. (United States)

    Elizalde, María; Urtasun, Raquel; Azkona, María; Latasa, María U; Goñi, Saioa; García-Irigoyen, Oihane; Uriarte, Iker; Segura, Victor; Collantes, María; Di Scala, Mariana; Lujambio, Amaia; Prieto, Jesús; Ávila, Matías A; Berasain, Carmen


    A precise equilibrium between cellular differentiation and proliferation is fundamental for tissue homeostasis. Maintaining this balance is particularly important for the liver, a highly differentiated organ with systemic metabolic functions that is endowed with unparalleled regenerative potential. Carcinogenesis in the liver develops as the result of hepatocellular de-differentiation and uncontrolled proliferation. Here, we identified SLU7, which encodes a pre-mRNA splicing regulator that is inhibited in hepatocarcinoma, as a pivotal gene for hepatocellular homeostasis. SLU7 knockdown in human liver cells and mouse liver resulted in profound changes in pre-mRNA splicing and gene expression, leading to impaired glucose and lipid metabolism, refractoriness to key metabolic hormones, and reversion to a fetal-like gene expression pattern. Additionally, loss of SLU7 also increased hepatocellular proliferation and induced a switch to a tumor-like glycolytic phenotype. Slu7 governed the splicing and/or expression of multiple genes essential for hepatocellular differentiation, including serine/arginine-rich splicing factor 3 (Srsf3) and hepatocyte nuclear factor 4α (Hnf4α), and was critical for cAMP-regulated gene transcription. Together, out data indicate that SLU7 is central regulator of hepatocyte identity and quiescence.

  4. Perceived stress and substance use in methadone-maintained smokers. (United States)

    Moitra, Ethan; Anderson, Bradley J; Stein, Michael D


    In methadone maintenance treatment programs (MMTPs), 80-90% of participants smoke cigarettes. Patients in MMTPs are at particular risk for life stress, and nicotine, as well as other substances like alcohol, benzodiazepines, cocaine, marijuana, and opiates have been shown to reduce the effects of stress. Use of these addictive substances to cope with stress may precipitate illicit opiate relapse in MMTP patients. In the current study, we examined the relationship between perceived stress and substance abuse. Participants were 315 cigarette smokers recruited from nine MMTPs for a smoking cessation study. Logistic regression was used to evaluate the adjusted association of perceived stress with dichotomous indicators of hazardous alcohol use and recent substance use at baseline. After controlling for demographic and smoking-related variables, perceived stress was associated positively and significantly with the likelihood of screening positive for hazardous drinking or alcohol-related problems (OR=1.13, 95%CI 1.02; 1.25), with the likelihood of recent cocaine use (OR=1.18, 95%CI 1.02; 1.37), and with the likelihood of recent benzodiazepine use (OR=1.24, 95%CI 1.07). Perceived stress may be a marker of patients' risk for illicit substance use, a known risk factor for illicit opiate relapse. These findings indicate that cigarette use might not be sufficient in managing stress and methadone-maintained persons turn to other substances for relief. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)

    D. M. Vani


    Full Text Available Tomato fruits are usually consumed soon after harvest, however, as they are mainly comprised of water, and its walls are fragile, facilitates the emergence of diseases, making necessary the use of preventive measures in the field in order to reduce incidence of disease. The objective is then to evaluate the effect of foliar application of fungicides on the final quality of tomato fruits in postharvest. There were 13 applications of foliar fungicides Azoxystrobin+Cyproconazol and Boscalida, 7 applications Tebuconazol+Trifoxistrobin and 17 applications of Propamocarb+Fluopicolide (Control. We analyzed the incidence of Fusarium sp. in fruits, decay percentage of fruit weight (g and Brix. For incidence of Fusarium sp. in fruits, treatments Tebuconazol+Trifoxistrobin and Azoxistrobin+Ciproconazol reduced by 14.3%, the pathogen in fruits. There was a decrease of 82% in the deterioration of fruits treated with Tebuconazol+Trifoxistrobin and 91% in those treated with Azoxistrobin+Ciproconazol. As for the weight gain, treatments Tebuconazol+Trifoxistrobin, Boscalida and Azoxistrobin+Ciproconazol reduced the weight gain in 8.12%, 20.8% and 38.8%, respectively, compared to the control. ° Brix values of fruits treated with Tebuconazol+Trifoxistrobin and Boscalida were higher than those treated with Azoxistrobin+Ciproconazol and Control (Propamocarb+Fluopicolide. It is concluded that the treatment carried out with Tebuconazol+Trifoxistrobin afforded the greatest benefits in maintaining the tomato fruits in harvest.

  6. Endothelial C-type natriuretic peptide maintains vascular homeostasis (United States)

    Moyes, Amie J.; Khambata, Rayomand S.; Villar, Inmaculada; Bubb, Kristen J.; Baliga, Reshma S.; Lumsden, Natalie G.; Xiao, Fang; Gane, Paul J.; Rebstock, Anne-Sophie; Worthington, Roberta J.; Simone, Michela I.; Mota, Filipa; Rivilla, Fernando; Vallejo, Susana; Peiró, Concepción; Sánchez Ferrer, Carlos F.; Djordjevic, Snezana; Caulfield, Mark J.; MacAllister, Raymond J.; Selwood, David L.; Ahluwalia, Amrita; Hobbs, Adrian J.


    The endothelium plays a fundamental role in maintaining vascular homeostasis by releasing factors that regulate local blood flow, systemic blood pressure, and the reactivity of leukocytes and platelets. Accordingly, endothelial dysfunction underpins many cardiovascular diseases, including hypertension, myocardial infarction, and stroke. Herein, we evaluated mice with endothelial-specific deletion of Nppc, which encodes C-type natriuretic peptide (CNP), and determined that this mediator is essential for multiple aspects of vascular regulation. Specifically, disruption of CNP leads to endothelial dysfunction, hypertension, atherogenesis, and aneurysm. Moreover, we identified natriuretic peptide receptor–C (NPR-C) as the cognate receptor that primarily underlies CNP-dependent vasoprotective functions and developed small-molecule NPR-C agonists to target this pathway. Administration of NPR-C agonists promotes a vasorelaxation of isolated resistance arteries and a reduction in blood pressure in wild-type animals that is diminished in mice lacking NPR-C. This work provides a mechanistic explanation for genome-wide association studies that have linked the NPR-C (Npr3) locus with hypertension by demonstrating the importance of CNP/NPR-C signaling in preserving vascular homoeostasis. Furthermore, these results suggest that the CNP/NPR-C pathway has potential as a disease-modifying therapeutic target for cardiovascular disorders. PMID:25105365

  7. Aspm specifically maintains symmetric proliferative divisions of neuroepithelial cells. (United States)

    Fish, Jennifer L; Kosodo, Yoichi; Enard, Wolfgang; Pääbo, Svante; Huttner, Wieland B


    The ASPM (abnormal spindle-like microcephaly-associated) protein has previously been implicated in the determination of human cerebral cortical size, but the cell biological basis of this regulation has not been studied. Here we investigate the role of Aspm in mouse embryonic neuroepithelial (NE) cells, the primary stem and progenitor cells of the mammalian brain. Aspm was found to be concentrated at mitotic spindle poles of NE cells and to be down-regulated with their switch from proliferative to neurogenic divisions. Upon RNA interference in telencephalic NE cells, Aspm mRNA is reduced, mitotic spindle poles lack Aspm protein, and the cleavage plane of NE cells is less frequently oriented perpendicular to the ventricular surface of the neuroepithelium. The alteration in the cleavage plane orientation of NE cells increases the probability that these highly polarized cells undergo asymmetric division, i.e., that apical plasma membrane is inherited by only one of the daughter cells. Concomitant with the resulting increase in abventricular cells in the ventricular zone, a larger proportion of NE cell progeny is found in the neuronal layer, implying a reduction in the number of NE progenitor cells upon Aspm knock-down relative to control. Our results demonstrate that Aspm is crucial for maintaining a cleavage plane orientation that allows symmetric, proliferative divisions of NE cells during brain development. These data provide a cell biological explanation of the primary microcephaly observed in humans with mutations in ASPM, which also has implications for the evolution of mammalian brains.

  8. Maintaining sleep and physical activity alleviate mood instability. (United States)

    Bowen, Rudy; Balbuena, Lloyd; Baetz, Marilyn; Schwartz, Laura


    Building on previous work indicating that mood instability is the hallmark of neuroticism, our aim was to examine whether changes in exercise, sleep duration and leisure predicted decreases in mood instability with time. We used data from 3374 participants of the British Health and Lifestyle Study who answered the Eysenck Personality Inventory-Neuroticism subscale (EPI-N) and the General Health Questionnaire on two occasions 7 years apart. We predicted mood instability scores derived from the EPI-N at follow-up using self-reported changes in exercise, sleep duration and leisure hours between the two time points as independent variables. We confirmed the observation that mood instability decreases with age. Maintaining one's exercise at baseline level decreased mood instability (beta=-0.21) while sleeping less increased mood instability (beta=0.14). Change in leisure time was not independently related to mood instability after accounting for the two other lifestyle factors. Personality, at least with regard to mood instability, can be modified by lifestyle factors. Exercise and sleep support mood stability and could be important components of preventative mental health (as well as physical health) benefits. © 2013.

  9. Sororin actively maintains sister chromatid cohesion. (United States)

    Ladurner, Rene; Kreidl, Emanuel; Ivanov, Miroslav P; Ekker, Heinz; Idarraga-Amado, Maria Helena; Busslinger, Georg A; Wutz, Gordana; Cisneros, David A; Peters, Jan-Michael


    Cohesion between sister chromatids is established during DNA replication but needs to be maintained to enable proper chromosome-spindle attachments in mitosis or meiosis. Cohesion is mediated by cohesin, but also depends on cohesin acetylation and sororin. Sororin contributes to cohesion by stabilizing cohesin on DNA. Sororin achieves this by inhibiting WAPL, which otherwise releases cohesin from DNA and destroys cohesion. Here we describe mouse models which enable the controlled depletion of sororin by gene deletion or auxin-induced degradation. We show that sororin is essential for embryonic development, cohesion maintenance, and proper chromosome segregation. We further show that the acetyltransferases ESCO1 and ESCO2 are essential for stabilizing cohesin on chromatin, that their only function in this process is to acetylate cohesin's SMC3 subunit, and that DNA replication is also required for stable cohesin-chromatin interactions. Unexpectedly, we find that sororin interacts dynamically with the cohesin complexes it stabilizes. This implies that sororin recruitment to cohesin does not depend on the DNA replication machinery or process itself, but on a property that cohesin acquires during cohesion establishment. © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

  10. Lamin A and microtubules collaborate to maintain nuclear morphology. (United States)

    Tariq, Zeshan; Zhang, Haoyue; Chia-Liu, Alexander; Shen, Yang; Gete, Yantenew; Xiong, Zheng-Mei; Tocheny, Claire; Campanello, Leonard; Wu, Di; Losert, Wolfgang; Cao, Kan


    Lamin A (LA) is a critical structural component of the nuclear lamina. Mutations within the LA gene (LMNA) lead to several human disorders, most striking of which is Hutchinson-Gilford Progeria Syndrome (HGPS), a premature aging disorder. HGPS cells are best characterized by an abnormal nuclear morphology known as nuclear blebbing, which arises due to the accumulation of progerin, a dominant mutant form of LA. The microtubule (MT) network is known to mediate changes in nuclear morphology in the context of specific events such as mitosis, cell polarization, nucleus positioning and cellular migration. What is less understood is the role of the microtubule network in determining nuclear morphology during interphase. In this study, we elucidate the role of the cytoskeleton in regulation and misregulation of nuclear morphology through perturbations of both the lamina and the microtubule network. We found that LA knockout cells exhibit a crescent shape morphology associated with the microtubule-organizing center. Furthermore, this crescent shape ameliorates upon treatment with MT drugs, Nocodazole or Taxol. Expression of progerin, in LA knockout cells also rescues the crescent shape, although the response to Nocodazole or Taxol treatment is altered in comparison to cells expressing LA. Together these results describe a collaborative effort between LA and the MT network to maintain nuclear morphology.

  11. Automated NFC enabled rural healthcare for reliable patient record maintainance. (United States)

    Sethia, Divyashikha; Jain, Shantanu; Kakkar, Himadri


    Body sensor networks can be used for health monitoring of patients by expert medical doctors, in remote locations like rural areas in developing countries, and can also be used to provide medical aid to areas affected by natural disasters in any part of the world. An important issue to be addressed, when the number of patients is large, is to reliably maintain the patient records and have simple automated mobile applications for healthcare helpers to use. We propose an automated healthcare architecture using NFC-enabled mobile phones and patients having their patient ID on RFID tags. It utilizes NFC-enabled mobile phones to read the patient ID, followed by automated gathering of healthcare vital parameters from body sensors using Bluetooth, analyses the information and transmits it to a medical server for expert feedback. With limited hospital resources and less training requirement for healthcare helpers through simpler applications, this automation of healthcare processing can provide time effective and reliable mass health consultation from medical experts in remote locations.

  12. Effective sharing of health records, maintaining privacy: a practical schema. (United States)

    Neame, Roderick


    A principal goal of computerisation of medical records is to join up care services for patients, so that their records can follow them wherever they go and thereby reduce delays, duplications, risks and errors, and costs. Healthcare records are increasingly being stored electronically, which has created the necessary conditions for them to be readily sharable. However simply driving the implementation of electronic medical records is not sufficient, as recent developments have demonstrated (1): there remain significant obstacles. The three main obstacles relate to (a) record accessibility (knowing where event records are and being able to access them), (b) maintaining privacy (ensuring that only those authorised by the patient can access and extract meaning from the records) and (c) assuring the functionality of the shared information (ensuring that the records can be shared non-proprietorially across platforms without loss of meaning, and that their authenticity and trustworthiness are demonstrable). These constitute a set of issues that need new thinking, since existing systems are struggling to deliver them. The solution to this puzzle lies in three main parts. Clearly there is only one environment suited to such widespread sharing, which is the World Wide Web, so this is the communications basis. Part one requires that a sharable synoptic record is created for each care event and stored in standard web-format and in readily accessible locations, on 'the web' or in 'the cloud'. To maintain privacy these publicly-accessible records must be suitably protected either stripped of identifiers (names, addresses, dates, places etc.) and/or encrypted: either way the record must be tagged with a tag that means nothing to anyone, but serves to identify and authenticate a specific record when retrieved. For ease of retrieval patients must hold an index of care events, records and web locations (plus any associated information for each such as encryption keys, context etc

  13. Epigenetic patterns in successful weight loss maintainers: a pilot study. (United States)

    Huang, Yen-Tsung; Maccani, Jennifer Z J; Hawley, Nicola L; Wing, Rena R; Kelsey, Karl T; McCaffery, Jeanne M


    DNA methylation changes occur in animal models of calorie restriction, simulating human dieting, and in human subjects undergoing behavioral weight loss interventions. This suggests that obese (OB) individuals may possess unique epigenetic patterns that may vary with weight loss. Here, we examine whether methylation patterns in leukocytes differ in individuals who lost sufficient weight to go from OB to normal weight (NW; successful weight loss maintainers; SWLMs) vs currently OB or NW individuals. This study examined peripheral blood mononuclear cell (PBMC) methylation patterns in NW (n=16, current/lifetime BMI 18.5-24.9) and OB individuals (n=16, current body mass index (BMI)⩾30), and SWLM (n=16, current BMI 18.5-24.9, lifetime maximum BMI ⩾30, average weight loss 57.4 lbs) using an Illumina Infinium HumanMethylation450 BeadArray. No leukocyte population-adjusted epigenome-wide analyses were significant; however, potentially differentially methylated loci across the groups were observed in ryanodine receptor-1 (RYR1; P=1.54E-6), myelin protein zero-like 3 (MPZL3; P=4.70E-6) and alpha 3c tubulin (TUBA3C; P=4.78E-6). In 32 obesity-related candidate genes, differential methylation patterns were found in brain-derived neurotrophic factor (BDNF; gene-wide P=0.00018). In RYR1, TUBA3C and BDNF, SWLM differed from OB but not NW. In this preliminary investigation, leukocyte SWLM DNA methylation patterns more closely resembled NW than OB individuals in three gene regions. These results suggest that PBMC methylation is associated with weight status.

  14. Maintaining Validity: The Development of the Concept of Trust

    Directory of Open Access Journals (Sweden)

    Judith E. Hupcey


    Full Text Available Maintaining validity while moving a concept to a higher level of maturity is a dilemma that faces all qualitative researchers. In this section, research projects related to the concept of trust will be used to illustrate how new studies can be built on previous ones and then all studies integrated to develop a comprehensive model without compromising validity. The multiple stages of inquiry will be elucidated using the strategies of deconstruction, development of a skeletal framework, and scaffolding as described by in the opening section by Morse and Mitcham. The strategy of deconstruction was used in the initial project (Morse, 2000, which was a multidisciplinary concept analysis to determine the level of conceptual maturity. Once it was determined that trust was not well developed in the context of health care interactions, literature was used as data (Morse, 2000 to advance the concept further for the purposes of concept clarification. Although this began the process of identifying the structural features of the concept, these data left us with many questions, particularly since the trust literature was context bound and thus not easily applied to health care relationships. A skeletal framework was then developed to investigate trust in health care relationships using grounded theory (Hupcey, Penrod, & Morse, 2000. This project also advanced the concept further toward maturity, but some aspects still remained unclear. For example, risk as a precondition for trust as found during the concept clarification was not necessarily seen when trust was applied to health care relationships. The strategy of scaffolding was then used as data collection continued with other types of participants and in different contexts to clarify discrepancies in the data and verify the developing model of the concept of trust in health care interactions (Hupcey, Clark, Hutcheson, & Thompson, in press; Thompson, Hupcey, & Clark, in press. Here, I focus on the process

  15. [The macrophage contribution for maintaining lymphatic vessel in cornea]. (United States)

    Maruyama, Kazuichi


    The presence of antigen-presenting cells and hem- and lymphangiogenesis in the cornea are risk factors for the rejection of corneal transplants. We previously reported that antigen-presenting cells such as macrophages (MPs) play an important role in the induction of lymphatic endothelial cells during inflammation. This prompted us to inquire whether the existence of lymphatic vessels in the cornea is associated with the activation of MPs during inflammation. To investigate this question, we performed suture placement on the cornea to induce inflammation. We found that a large number of MPs were recruited and that lymphatic vessels were formed in response. Next, as C57BL/6 mice have a higher rejection rate after corneal transplantation than BALB/c mice, we compared the corneas of C57BL/6 and BALB/c mice under normal and inflamed conditions. We found that the number of spontaneously formed lymphatic vessels in the C57BL/6 corneas was significantly greater than in the BALB/c corneas, and that there were more activated MPs in the C57BL/6 corneas than in the BALB/c corneas. Additionally, to confirm that activated MPs induced and maintained lymphatic vessels in the cornea, we depleted the number of MPs in C57BL/6 mice via clodronate liposomes. We found that MP depletion reduced the spontaneous formation of lymphatic vessels and reduced inflammation-induced lymphangiogenesis relative to control mice. Finally, we found that mice deficient in MP markers had fewer spontaneously formed lymphatic vessels and less lymphangiogenesis than control C57BL/6 mice. The evidence gathered in this study leads us to conclude that activated MPs appear to play an important role in the formation of new lymphatic vessels and in their maintenance.

  16. Maintaining Sentiment Polarity in Translation of User-Generated Content

    Directory of Open Access Journals (Sweden)

    Lohar Pintu


    Full Text Available The advent of social media has shaken the very foundations of how we share information, with Twitter, Facebook, and Linkedin among many well-known social networking platforms that facilitate information generation and distribution. However, the maximum 140-character restriction in Twitter encourages users to (sometimes deliberately write somewhat informally in most cases. As a result, machine translation (MT of user-generated content (UGC becomes much more difficult for such noisy texts. In addition to translation quality being affected, this phenomenon may also negatively impact sentiment preservation in the translation process. That is, a sentence with positive sentiment in the source language may be translated into a sentence with negative or neutral sentiment in the target language. In this paper, we analyse both sentiment preservation and MT quality per se in the context of UGC, focusing especially on whether sentiment classification helps improve sentiment preservation in MT of UGC. We build four different experimental setups for tweet translation (i using a single MT model trained on the whole Twitter parallel corpus, (ii using multiple MT models based on sentiment classification, (iii using MT models including additional out-of-domain data, and (iv adding MT models based on the phrase-table fill-up method to accompany the sentiment translation models with an aim of improving MT quality and at the same time maintaining sentiment polarity preservation. Our empirical evaluation shows that despite a slight deterioration in MT quality, our system significantly outperforms the Baseline MT system (without using sentiment classification in terms of sentiment preservation. We also demonstrate that using an MT engine that conveys a sentiment different from that of the UGC can even worsen both the translation quality and sentiment preservation.

  17. Management of wound infection after lumbar arthrodesis maintaining the instrumentation

    Directory of Open Access Journals (Sweden)

    Asdrubal Falavigna


    Full Text Available OBJECTIVE: To determinate whether a surgical protocol with immediate extensive debridement, closed irrigation system and antibiotic therapy would be effective to achieve healing of deep wound infection without removing the instrumentation.METHODS: Prospective cohort study with 19 patients presenting degenerative spinal stenosis or degenerative spondylolisthesis, who developed infection after posterior lumbar arthrodesis. The diagnosis was confirmed by a microbial culture from subfascial lumbar fluid and/or blood. Patients were treated with a protocol of wound exploration, extensive flushing and debridement, placement of a closed irrigation system that was maintained for five days and intravenous antibiotics. The instrumentation system was not removed.RESULTS: Mean age was 59.31 (±13.17 years old and most patients were female (94.7%; 18/19. The mean period for the identification of the infection was 2 weeks and 57.9% underwent a single wound exploration. White blood count, erythrocyte sedimentation rate and C-reactive protein showed a significant decrease post-treatment when compared to pre-treatment values. A significant reduction of erythrocyte sedimentation rate and C-reactive protein was also observed at the final evaluation. No laboratory test was useful to predict the need for more than one debridement.CONCLUSION: Patients with wound infection after instrumentation can be treated without removal of the instrumentation through wound exploration, extensive flushing, debridement of necrotic tissue, closed irrigation system during 5 days and proper antibiotic therapy. The blood tests were not useful to predict surgical re-interventions.

  18. Academic Advising and Maintaining Major: Is There a Relation?

    Directory of Open Access Journals (Sweden)

    Maram S. Jaradat


    Full Text Available The purpose of this study is to investigate the effect of academic advising on changing or maintaining majors in university degrees. It is also a goal of the study to determine which semester students change their majors and whether advising contributes to that change. Through this correlational study, the researchers explored students’ perceptions about the academic advising they received and the relationship of its absence on students’ major change. The participants were 1725 undergraduate students from all year levels. The survey used to collect the data for this study is: the Influences on Choice of Major survey. Based on the findings, it was found that university advisors have a very poor effect on students’ decisions to select their majors as 45.6% of the 1725 participants indicated no influence of advising in their survey answers. Whereas career advancement opportunities, students’ interests, and job opportunities indicate a strong effect on their majors’ selections, as they score the highest means of 3.76, 3.73, and 3.64, respectively. In addition, findings show that students are most likely changing their majors in their second year, and specifically in the second semester. Second year major change scored 36.9% in the second semester and 30.9% in the first semester. More importantly, results indicate that there is a positive significant correlation between college advisors and major change in the second year (p = 0.000. It is to researchers’ understanding based on the findings that when students receive enough academic advising in the first year of study, and this advising continues steadily into the next year, the probability of students changing their majors decreases greatly.

  19. Aminoglycoside-induced vestibular injury: maintaining a sense of balance. (United States)

    Ariano, Robert E; Zelenitsky, Sheryl A; Kassum, Diamond A


    To describe the mechanism and risk factors for the development of aminoglycoside-induced vestibular injury and discuss their implications for therapeutic monitoring of aminoglycoside antibiotics. A MEDLINE search (1975-January 2008) was performed to identify literature on aminoglycoside-induced vestibular injury and risk factors associated with this outcome and their impact on therapeutic drug monitoring. Additional references were identified through review of bibliographies of identified articles. Data on the mechanisms of vestibular toxicity and its development in association with aminoglycoside exposure were extracted from identified references. The mechanism leading to the development of irreversible vestibular injury from exposure to aminoglycosides appears to be through the excessive production of oxidative free radicals. This production and subsequent toxicity appears to be a time-dependent process and is unrelated to dose or serum concentration. For similarly designed studies, the pooled incidence of vestibular toxicity is 10.9% for gentamicin, 7.4% for amikacin, 3.5% for tobramycin, and 1.1% for netilmicin. Current evidence suggests that this form of drug toxicity is not restricted to traditionally dosed systemic therapy, since intraperitoneal administration, high-dose once-daily administration, topical inhalation, and eardrop administration have all been associated with the development of this adverse outcome. Given the lack of association between serum concentrations and vestibulotoxicity, it is imperative for the pharmacist to interview the patient and not focus solely on maintaining target range drug concentrations. Minimizing the duration of exposure to aminoglycosides is recommended to reduce the risk from this form of drug toxicity.

  20. Estrogen Receptor α Is Required for Maintaining Baseline Renin Expression. (United States)

    Lu, Ko-Ting; Keen, Henry L; Weatherford, Eric T; Sequeira-Lopez, Maria Luisa S; Gomez, R Ariel; Sigmund, Curt D


    Enzymatic cleavage of angiotensinogen by renin represents the critical rate-limiting step in the production of angiotensin II, but the mechanisms regulating the initial expression of the renin gene remain incomplete. The purpose of this study is to unravel the molecular mechanism controlling renin expression. We identified a subset of nuclear receptors that exhibited an expression pattern similar to renin by reanalyzing a publicly available microarray data set. Expression of some of these nuclear receptors was similarly regulated as renin in response to physiological cues, which are known to regulate renin. Among these, only estrogen receptor α (ERα) and hepatic nuclear factor α have no known function in regulating renin expression. We determined that ERα is essential for the maintenance of renin expression by transfection of small interfering RNAs targeting Esr1, the gene encoding ERα, in renin-expressing As4.1 cells. We also observed that previously characterized negative regulators of renin expression, Nr2f2 and vitamin D receptor, exhibited elevated expression in response to ERα inhibition. Therefore, we tested whether ERα regulates renin expression through an interaction with Nr2f2 and vitamin D receptor. Renin expression did not return to baseline when we concurrently suppressed both Esr1 and Nr2f2 or Esr1 and vitamin D receptor mRNAs, strongly suggesting that Esr1 regulates renin expression independent of Nr2f2 and vitamin D receptor. ERα directly binds to the hormone response element within the renin enhancer region. We conclude that ERα is a previously unknown regulator of renin that directly binds to the renin enhancer hormone response element sequence and is critical in maintaining renin expression in renin-expressing As4.1 cells. © 2016 American Heart Association, Inc.

  1. Chromosomal rearrangements maintain a polymorphic supergene controlling butterfly mimicry (United States)

    Joron, Mathieu; Frezal, Lise; Jones, Robert T.; Chamberlain, Nicola L.; Lee, Siu F.; Haag, Christoph R.; Whibley, Annabel; Becuwe, Michel; Baxter, Simon W.; Ferguson, Laura; Wilkinson, Paul A.; Salazar, Camilo; Davidson, Claire; Clark, Richard; Quail, Michael A.; Beasley, Helen; Glithero, Rebecca; Lloyd, Christine; Sims, Sarah; Jones, Matthew C.; Rogers, Jane; Jiggins, Chris D.; ffrench-Constant, Richard H.


    Supergenes are tight clusters of loci that facilitate the co-segregation of adaptive variation, providing integrated control of complex adaptive phenotypes1. Polymorphic supergenes, in which specific combinations of traits are maintained within a single population, were first described for ‘pin’ and ‘thrum’ floral types in Primula1 and Fagopyrum2, but classic examples are also found in insect mimicry3–5 and snail morphology6. Understanding the evolutionary mechanisms that generate these co-adapted gene sets, as well as the mode of limiting the production of unfit recombinant forms, remains a substantial challenge7–10. Here we show that individual wing-pattern morphs in the polymorphic mimetic butterfly Heliconius numata are associated with different genomic rearrangements at the supergene locus P. These rearrangements tighten the genetic linkage between at least two colour-pattern loci that are known to recombine in closely related species9–11, with complete suppression of recombination being observed in experimental crosses across a 400-kilobase interval containing at least 18 genes. In natural populations, notable patterns of linkage disequilibrium (LD) are observed across the entire P region. The resulting divergent haplotype clades and inversion breakpoints are found in complete association with wing-pattern morphs. Our results indicate that allelic combinations at known wing-patterning loci have become locked together in a polymorphic rearrangement at the Plocus, forming a supergene that acts as a simple switch between complex adaptive phenotypes found in sympatry. These findings highlight how genomic rearrangements can have a central role in the coexistence of adaptive phenotypes involving several genes acting in concert, by locally limiting recombination and gene flow. PMID:21841803

  2. Components for Maintaining and Publishing Earth Science Vocabularies (United States)

    Cox, S. J. D.; Yu, J.


    Shared vocabularies are an important aid to geoscience data interoperability. Many organizations maintain useful vocabularies, with Geologic Surveys having a particularly long history of vocabulary and lexicon development. However, the mode of publication is heterogeneous, ranging from PDFs and HTML web pages, spreadsheets and CSV, through various user-interfaces and APIs. Update and maintenance ranges from tightly-governed and externally opaque, through various community processes, all the way to crowd-sourcing ('folksonomies'). A general expectation, however, is for greater harmonization and vocabulary re-use. In order to be successful this requires (a) standardized content formalization and APIs (b) transparent content maintenance and versioning. We have been trialling a combination of software dealing with registration, search and linking. SKOS is designed for formalizing multi-lingual, hierarchical vocabularies, and has been widely adopted in earth and environmental sciences. SKOS is an RDF vocabulary, for which SPARQL is the standard low-level API. However, for interoperability between SKOS vocabulary sources, a SKOS-based API (i.e. based on the SKOS predicates prefLabel, broader, narrower, etc) is required. We have developed SISSvoc for this purpose, and used it to deploy a number of vocabularies on behalf of the IUGS, ICS, NERC, OGC, the Australian Government, and CSIRO projects. SISSvoc Search provides simple search UI on top of one or more SISSvoc sources. Content maintenance is composed of many elements, including content-formalization, definition-update, and mappings to related vocabularies. Typically there is a degree of expert judgement required. In order to provide confidence in users, two requirements are paramount: (i) once published, a URI that denotes a vocabulary item must remain dereferenceable; (ii) the history and status of the content denoted by a URI must be available. These requirements match the standard 'registration' paradigm which is

  3. Beverage osmolality as a marker for maintaining appropriate body hydration. (United States)

    Sadowska1, Anna; Świderski, Franciszek; Rakowska, Rita; Waszkiewicz-Robak, Bożena; Żebrowska-Krasuska, Małgorzata; Dybkowska, Ewa

    Osmolalities can be useful markers for determining whether given beverages are suited for maintaining an adequate hydration of the body. Losing 2% of body water relative to body mass reduces the efficiency of body function when undertaking physical effort by around 20%. Deficiencies in water intakes approaching 5-8% of body mass, double the impairment to the body’s physical and mental functioning, whereas at a level of 10% the body becomes incapable of performing any sort of physical effort. For such reasons the body’s hydration status is vital to its functioning. To asses osmolalities as measured in various types of commercially available mineral waters and non-alcoholic beverages containing different amounts of extracts. Test materials were commercially available mineral waters (of low, medium and high mineral content) along with juices, nectars and drinks that are isotonic, energising and those described as being ‘light’ and sparkling. Osmolality was measured by the 800CL Osmometer instrument from TridentMed whilst the RL-type refractometer was used for determining extract values. Isotonic drinks were found to have the same osmotic pressures as bodily fluids at 275 – 295 mOsm/kg water. The osmotic pressure in mineral waters depended on the extent of mineralisation and ranged from 13 mOsm / kg water (low mineral content) to 119 mOsm/kg water (high mineral content). Low osmolalities were also found in ‘light’ drinks (from 29.3 to 34 mOsm/kg water). Juices, nectars, energising drinks and colas typically have high sugar contents and have high osmolalities ranging 492 – 784 mOsm / kg water. Statistical analysis demonstrated significant associations (p drinks according to similar osmolalities and extract content. Osmolalities measured in beverages are a marker that permits drinks to be classified into groups according to their tonicity and their ability to ensure that the body is properly hydrated; this becoming vital in cases when the body requires

  4. Should we maintain baby hatches in our society?

    Directory of Open Access Journals (Sweden)

    Asai Atsushi


    Full Text Available Abstract Background A baby hatch called the “Stork’s Cradle” has been in place at Jikei Hospital in Kumamoto City, Japan, since May 10, 2007. Babyklappes were first established in Germany in 2000, and there are currently more than 90 locations. Attitudes regarding baby hatches are divided in Japan and neither opinions for nor against baby hatches have thus far been overwhelming. To consider the appropriateness of baby hatches, we present and examine the validity of each major objection to establishing baby hatches. Discussion There are various objections to baby hatches as follows: It violates a child’s right to know the identity of his or her biological parents by allowing anonymous birth; it neglects fulfillment of the biological parents’ basic obligation to raise their child and its very availability induces abandonment of infants; some people abuse it for very selfish reasons; it cannot save babies’ lives; the rights of one parent can be ignored if the other surrenders a child without his or her consent; it puts a baby in medical jeopardy; and it has no clear legal basis. The authors would argue that there are many plausible refutations for each objection mainly based on priority of child’s right to life, pregnant women’s vulnerability and necessity of anonymity, social responsibility to protect and raise children, differences between dropping a child off at a baby hatch and child neglect, limited function of social childcare center, inevitability of abuse by a minority of people, necessary distinction between outcomes that occur only because baby hatches exist and those that occur regardless of their existence, important local direct and upmost measures for women in trouble, and difference between ambiguous legality and illegality. Summary We argue that a certain number of baby hatches should continue to be established as a last resort, in a form that can maintain anonymity if the parent dropping the child off so desires. It

  5. Antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation. (United States)

    Lafuente-Lafuente, Carmelo; Valembois, Lucie; Bergmann, Jean-François; Belmin, Joël


    -cause mortality. Other antiarrhythmics did not seem to modify mortality, but our data could be underpowered to detect mild increases in mortality for several of the drugs studied.Several class IA (disopyramide, quinidine), IC (flecainide, propafenone) and III (amiodarone, dofetilide, dronedarone, sotalol) drugs significantly reduced recurrence of atrial fibrillation (OR 0.19 to 0.70, number needed to treat to beneft (NNTB) 3 to 16). Beta-blockers (metoprolol) also significantly reduced atrial fibrillation recurrences (OR 0.62, 95% CI 0.44 to 0.88, NNTB 9).All analysed drugs increased withdrawals due to adverse affects and all but amiodarone, dronedarone and propafenone increased pro-arrhythmia. Only 11 trials reported data on stroke. None of them found any significant difference with the exception of a single trial than found less strokes in the group treated with dronedarone compared to placebo. This finding was not confirmed in others studies on dronedarone.We could not analyse heart failure and use of anticoagulation because few original studies reported on these measures. Several class IA, IC and III drugs, as well as class II drugs (beta-blockers), are moderately effective in maintaining sinus rhythm after conversion of atrial fibrillation. However, they increase adverse events, including pro-arrhythmia, and some of them (disopyramide, quinidine and sotalol) may increase mortality. Possible benefits on clinically relevant outcomes (stroke, embolism, heart failure) remain to be established.

  6. The Role of Filtration in Maintaining Clean Heat Exchanger Coils

    Energy Technology Data Exchange (ETDEWEB)

    Li Yang; James E. Braun; Eckhard A. Groll


    The main purpose of the study was to investigate the role of filtration in maintaining clean heat exchanger coils and overall performance. Combinations of 6 different levels of filtration (MERV 14, 11, 8, 6, 4, and no filter) and 4 different coils (an eight-row lanced-fin coil, HX8L), (an eight-row wavy-fin coil, HX8W), (a four-row lanced-fin coil, HX4L) and (a two-row lanced-fin coil, HX2L) were tested at 4 different air velocities (1.52, 2.03, 2.54,3.05 m/s (300, 400, 500, 600 ft/min)). The fouled conditions were obtained after injection of 600 grams of ASHRAE standard dust upstream of the filter/coil combination. This magnitude of dust is representative of a year of normal operation for an air conditioning system. The air-side pressure drops of the coils and filters and air-side heat transfer coefficients of the coils were determined from the measurements under the clean and fouled conditions. Depending upon the filter and coil test, the coil pressure drops increased in the range of 6%-30% for an air velocity at 2.54 m/s (500 ft/min). The impact was significantly greater for tests performed without a filter. The largest relative effect of fouling on pressure drop occurs for coils with fewer rows and having lanced fins. Coils with a greater number of rows can hold more dust so that a fixed amount of dust has a relatively smaller impact. The impact of fouling on air-side heat transfer coefficients was found to be relatively small. In some cases, heat transfer was actually enhanced due to additional turbulence caused by the presence of dust. The experimental results for pressure drops and heat transfer coefficients were correlated and the correlations were implemented within computer models of prototypical rooftop air conditioners and used to evaluate the impact of fouling on cooling capacity and EER. The equipment cooling capacity is reduced with fouling primarily because of a decrease in air flow due to the increase pressure drop rather than due to changes in h

  7. Microbiological testing of devices used in maintaining peripheral venous catheters. (United States)

    Rossini, Fernanda de Paula; Andrade, Denise de; Santos, Lissandra Chaves de Sousa; Ferreira, Adriano Menis; Tieppo, Caroline; Watanabe, Evandro


    to evaluate the use of peripheral venous catheters based on microbiological analysis of devices (dressing and three-way stopcocks) and thus contribute to the prevention and infection control. this was a prospective study of microbiological analysis of 30 three-way stopcocks (external surfaces and lumens) and 30 dressing used in maintaining the peripheral venous catheters of hospitalized adult patients. all external surfaces, 40% of lumens, and 86.7% of dressing presented bacterial growth. The main species isolated in the lumen were 50% coagulase-negative Staphylococcus, 14.3% Staphylococcus aureus, and 14.3% Pseudomonas aeruginosa. Fifty nine percent of multidrug-resistant bacteria were isolated of the three-way stopcocks, 42% of the lumens, and 44% of the dressing with a predominance of coagulase-negative Staphylococcus resistant to methicillin. Besides, 18% gram-negative bacteria with resistance to carbapenems were identified from multidrug-resistant bacteria on the external surfaces of the three-way stopcocks. it is important to emphasize the isolation of coagulase-negative Staphylococcus and gram-negative bacteria resistant to methicillin and carbapenems in samples of devices, respectively, which reinforces the importance of nursing care in the maintenance of the biologically safe environment as well as prevention and infection control practices. avaliar o uso de cateteres venosos periféricos com base em análises microbiológicas de dispositivos (curativos e torneiras de três vias - T3Vs) e assim contribuir para a prevenção e controle de infecção. estudo prospectivo de análise microbiológica de 30 T3Vs (superfícies externas e lúmens) e 30 curativos utilizados na manutenção dos cateteres venosos periféricos de pacientes adultos hospitalizados. todas as superfícies externas, 40% dos lúmens e 86,7% dos curativos apresentaram crescimento bacteriano. As principais espécies isoladas no lúmen foram 50% Staphylococcus coagulase-negativa, 14

  8. 21 CFR 105.66 - Label statements relating to usefulness in reducing or maintaining body weight. (United States)


    ... reducing or maintaining body weight. 105.66 Section 105.66 Food and Drugs FOOD AND DRUG ADMINISTRATION... Label Statements § 105.66 Label statements relating to usefulness in reducing or maintaining body weight... because of usefulness in reducing or maintaining body weight shall bear: (1) Nutrition labeling in...

  9. Maintaining adequate nutrient supply - Principles, decision-support tools, and best management practices [Chapter 6 (United States)

    Robert B. Harrison; Douglas A. Maguire; Deborah Page-Dumroese


    Maintaining adequate nutrient supply to maintain or enhance tree vigor and forest growth requires conservation of topsoil and soil organic matter. Sometimes nutrient amendments are also required to supplement inherent nutrient-pool limitations or replenish nutrients removed in harvested material. The goal is to maintain the productive potential of the soil and, when...

  10. 43 CFR 2.5 - Does DOI maintain an index of its reading room materials? (United States)


    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Does DOI maintain an index of its reading... a FOIA Request § 2.5 Does DOI maintain an index of its reading room materials? Each bureau will maintain and make available for public inspection and copying a current subject-matter index of its reading...

  11. Clinical Success of Fiber-reinforced Composite Resin as a Space Maintainer. (United States)

    Kirzioğlu, Zuhal; Çiftçi, Z Zahit; Yetiş, Ceylan Ç


    The early loss of deciduous molars is a frequently encountered problem in dentistry. Various space maintainer designs were developed to prevent the loss of the space. The aim of this study was to evaluate long-term clinical performance and survival rates of fiber-reinforced composite resin (FRCR) as a space maintainer clinically. This study was designed on 44 children who had early missed deciduous molars. Space maintainers were prepared on plaster models of patients and fixed directly to the adjacent teeth. Survival rate and whether it causes any damage to adjacent teeth were examined clinically and radio-graphically for 24 months or until failure. Kaplan-Meier survival analysis was used for the statistical analyses. Overall, 16.2% of space maintainers were dislodged and accepted to be failed at the end of 12 months. At the 24-month control, 52.2% success was stated with the FRCR space maintainer and because of permanent tooth eruption, 31.8% of space maintainer were taken out. The mean duration of space maintainers was measured to be 14.8 ± 3.48 months. There was no statistical significance between survival time and gender, tooth number, localization, and measured space (p > 0.05). After all 24 months follow-up, as well as esthetic properties of FRCR space maintainer, their applicability in a single seance and strength against the forces are determined as the advantages of the technique. The FRCR space maintainers can be thought of as alternatives to metal space maintainers.

  12. Maintaining evolvability

    Indian Academy of Sciences (India)


    Dec 23, 2008 ... inherit a disproportionate number of genes acting additively on the trait, thus increasing genetic variance. For these ... Keywords. polygenes; additive genetic variance; epistasis; dominance; selection response; quantitative genetics. Journal of ..... The effect of epistasis on homozygous viability depression in.

  13. Maintaining Quality

    Directory of Open Access Journals (Sweden)

    Ulrich Kohler


    Full Text Available Survey Research Methods has slightly revised its publication policies. Firstly, starting with the publication of this Editorial, SRM will accept -- under specified conditions -- manuscripts that discuss experiments in non-probability samples for peer-review. Secondly, SRM will require authors to publish replication materials of their study as Online supplement to their article. Finally, Survey Research Methods will publish replication studies of articles published in the journal. This Editorial gives reasons for these changes.

  14. Maintaining evolvability

    Indian Academy of Sciences (India)

    Yet, populations typically have a great deal of additive variance, and do not seem to run out of genetic variability even after many generations of directional selection. Long-term selection experiments show that populations continue to retain seemingly undiminished additive variance despite large changes in the mean value ...

  15. 9 CFR 381.480 - Label statements relating to usefulness in reducing or maintaining body weight. (United States)


    ... usefulness in reducing or maintaining body weight. 381.480 Section 381.480 Animals and Animal Products FOOD... maintaining body weight. (a) General requirements. Any product that purports to be or is represented for special dietary use because of usefulness in reducing body weight shall bear: (1) Nutrition labeling in...

  16. 9 CFR 317.380 - Label statements relating to usefulness in reducing or maintaining body weight. (United States)


    ... usefulness in reducing or maintaining body weight. 317.380 Section 317.380 Animals and Animal Products FOOD... or maintaining body weight. (a) General requirements. Any product that purports to be or is represented for special dietary use because of usefulness in reducing body weight shall bear: (1) Nutrition...

  17. Using an anterior chamber maintainer to control intraocular pressure during phacoemulsification. (United States)

    Blumenthal, M; Assia, E I; Chen, V; Avni, I


    We describe a phacoemulsification technique that uses an anterior chamber maintainer (ACM) to control intraocular pressure. Continuous irrigation through the ACM maintains pressurized intraocular conditions throughout surgery and when the automated system is not activated. Intraocular pressure is stabilized at predetermined levels with minor fluctuations. Viscoelastics can be used in conjunction with the ACM.

  18. Engineering Probiotics that Improve Warfighter Performance by Maintaining Lean Body Mass and Inhibiting Anxiety (United States)


    warfighter performance by maintaining lean body mass and inhibiting anxiety. Sb. GRANT NUMBER N00014-14-1-0487 Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...Final Technical Report Grant number: ONR N00014-14-1-0487 Title: Engineering probiotics that improve warfighter performance by maintaining lean body

  19. 31 CFR 358.16 - Are BECCS and CUBES accounts maintained separately from the STRIPS program? (United States)


    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Are BECCS and CUBES accounts maintained separately from the STRIPS program? 358.16 Section 358.16 Money and Finance: Treasury Regulations... Are BECCS and CUBES accounts maintained separately from the STRIPS program? BECCS and CUBES accounts...

  20. 25 CFR 115.701 - What types of accounts are maintained for Indian trust funds? (United States)


    ... ACTIVITIES TRUST FUNDS FOR TRIBES AND INDIVIDUAL INDIANS Trust Fund Accounts: General Information § 115.701 What types of accounts are maintained for Indian trust funds? Indian trust funds are deposited in... 25 Indians 1 2010-04-01 2010-04-01 false What types of accounts are maintained for Indian trust...

  1. Emergo : a tool for improving maintainability of preprocessor-based product lines

    DEFF Research Database (Denmark)

    Ribeiro, Márcio; Tolêdo, Társis; Winther, Johnni


    When maintaining a feature in preprocessor-based Software Product Lines (SPLs), developers are susceptible to introduce problems into other features. This is possible because features eventually share elements (like variables and methods) with the maintained one. This scenario might be even worse...

  2. Who Maintains/Relinquishes Which Language How and Why? A Response to Michael Clyne. (United States)

    Wei, Li


    Response to an article on multiculturalism and the status of community languages in Australia, focusing on issues of language maintenance and shift emerging from the article and adding examples from other countries. Questions addressed include who is responsible for maintaining community languages, which are maintained, how this is done, and why,…

  3. 36 CFR 1236.26 - What actions must agencies take to maintain electronic information systems? (United States)


    ... take to maintain electronic information systems? 1236.26 Section 1236.26 Parks, Forests, and Public... electronic information systems? (a) Agencies must maintain inventories of electronic information systems and... electronic information systems that is adequate to: (1) Specify all technical characteristics necessary for...

  4. 48 CFR 1806.202 - Establishing or maintaining alternative sources. (NASA supplements paragraphs (a) and (b)) (United States)


    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Establishing or maintaining alternative sources. (NASA supplements paragraphs (a) and (b)) 1806.202 Section 1806.202 Federal Acquisition... maintaining alternative sources. (NASA supplements paragraphs (a) and (b)) (a) The authority of FAR 6.202 is...

  5. 9 CFR 312.10 - Official mark for maintaining the identity and integrity of samples. (United States)


    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Official mark for maintaining the identity and integrity of samples. 312.10 Section 312.10 Animals and Animal Products FOOD SAFETY AND... § 312.10 Official mark for maintaining the identity and integrity of samples. The official mark for use...

  6. On the impact of DSL tools on the maintainability of language implementations

    NARCIS (Netherlands)

    P. Klint (Paul); T. van der Storm (Tijs); J.J. Vinju (Jurgen); C. Brabrand (Claus); P.-E. Moreau


    htmlabstractDoes the use of DSL tools improve the maintainability of language implementations compared to implementations from scratch? We present empirical results on aspects of maintainability of six implementations of the same DSL using different languages (Java, JavaScript, C#) and DSL tools

  7. 20 CFR 200.5 - Protection of privacy of records maintained on individuals. (United States)


    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Protection of privacy of records maintained... ADMINISTRATION GENERAL ADMINISTRATION § 200.5 Protection of privacy of records maintained on individuals. (a... compliance with the Privacy Act of 1974 (Pub. L. 93-579). These regulations apply to all record systems...

  8. 46 CFR 11.713 - Requirements for maintaining current knowledge of waters to be navigated. (United States)


    ... 46 Shipping 1 2010-10-01 2010-10-01 false Requirements for maintaining current knowledge of waters... § 11.713 Requirements for maintaining current knowledge of waters to be navigated. (a) If a first class pilot has not served over a particular route within the past 60 months, that person's license or MMC...

  9. Fixed space maintainers combined with open-face stainless steel crowns. (United States)

    Yilmaz, Yucel; Kocogullari, Mutlu Elcin; Belduz, Nihal


    This study investigates the clinical performance of fixed space maintainers placed on seriously damaged abutment teeth. Crowns were placed on damaged abutment primary teeth. Fixed space maintainers were prepared by using rectangular wire between the window in the facial surface of the crowns and other abutment teeth and were subsequently bonded with a flowable resin composite. This procedure was introduced clinically, and the cases were observed over a period of twelve months. Twenty-seven fixed space maintainers (25 on lower jaw, two on upper jaw) were included in this study. No clinical failure was recorded in any of the cases in the observation time, and the rate of clinical performance was 100%. The study shows the effectiveness of fixed space maintainers combined with stainless steel crowns ("open-face fixed space maintainers") which were placed on primary molar teeth used as abutments in cases with extensive caries and loss of occlusogingival dimension.

  10. Multi-Voxel Decoding and the Topography of Maintained Information During Visual Working Memory (United States)

    Lee, Sue-Hyun; Baker, Chris I.


    The ability to maintain representations in the absence of external sensory stimulation, such as in working memory, is critical for guiding human behavior. Human functional brain imaging studies suggest that visual working memory can recruit a network of brain regions from visual to parietal to prefrontal cortex. In this review, we focus on the maintenance of representations during visual working memory and discuss factors determining the topography of those representations. In particular, we review recent studies employing multi-voxel pattern analysis (MVPA) that demonstrate decoding of the maintained content in visual cortex, providing support for a “sensory recruitment” model of visual working memory. However, there is some evidence that maintained content can also be decoded in areas outside of visual cortex, including parietal and frontal cortex. We suggest that the ability to maintain representations during working memory is a general property of cortex, not restricted to specific areas, and argue that it is important to consider the nature of the information that must be maintained. Such information-content is critically determined by the task and the recruitment of specific regions during visual working memory will be both task- and stimulus-dependent. Thus, the common finding of maintained information in visual, but not parietal or prefrontal, cortex may be more of a reflection of the need to maintain specific types of visual information and not of a privileged role of visual cortex in maintenance. PMID:26912997

  11. Troubleshooting and Maintaining Your PC All-in-One Desk Reference For Dummies

    CERN Document Server

    Gookin, Dan


    Maintaining a PC is important, and troubleshooting a PC can be a challenge. Dan Gookin is great at explaining how to handle common PC problems, and he's provided a complete, plain-English manual in Troubleshooting & Maintaining Your PC All-in-One For Dummies. Liberally laced with Dan's famous humor and clear instructions, Troubleshooting & Maintaining Your PC All-in-One For Dummies is divided into six minibooks covering hardware, software, laptops, Internet, networking, and maintenance. Each one gives you some background on what causes common problems, to help you understand what's wrong as we

  12. Book Review: Data Management for Researchers: Organize, Maintain and Share Your Data for Research Success

    Directory of Open Access Journals (Sweden)

    Enid Y. Karr


    Full Text Available Book review of Data Management for Researchers: Organize, Maintain and Share your Data for Research Success by Kristin Briney, Exeter, UK: Pelagic Publishing, 2015. ISBN 978-1-78427-011-7

  13. Strategies for maintaining emotional stability: The case of nurses in private health care industry

    National Research Council Canada - National Science Library

    Pushpika Subhashinie Mullakanda; Kumudinei Dissanayake


    This study examines the emotional intelligence (EI) of nurses by differentiating inter-personal and intra-personal dimensions, and explores the measures taken by them to maintain emotional stability...

  14. Maintaining placement of temporary enteral feeding tubes in adults: a critical appraisal of the evidence. (United States)

    Stepter, Catherine R


    Maintaining placement of temporary enteral feeding tubes requires ongoing bedside nursing assessment. Tube placement verification is essential to detect and minimize adverse effects. A critical appraisal of current evidence and best practice recommendations regarding temporary feeding tubes is provided.

  15. The now habit at work: perform optimally, maintain focus, and ignite motivation in yourself and others

    National Research Council Canada - National Science Library

    Fiore, Neil A


    ... rather than seeing only obstacles. This one-of-a-kind program offers tools to enable superior quality work that creates work-life balance, strategies to maintain focus and self-confidence, tips to conquer stress through effective time...

  16. 15TH Conference on Military Medicine, "A Challenge to Readiness: Maintaining Currency in Military Education"

    National Research Council Canada - National Science Library

    Cloonan, Clifford


    ...: Maintaining Currency in Military Medical Education." These Proceedings serve as a record of the Service's Surgeons General nominees' contributions toward predicting the changes that will affect military medical practice over the next twenty to thirty...

  17. Bimetallic devices help maintain constant sealing forces down to cryogenic temperatures (United States)

    De Boskey, W. R.


    Tantalum washers compensate for different thermal coefficients of expansion between stainless steel and an aluminum O-ring. The washers have sufficient thickness to maintain a vacuum seal from room to cryogenic temperatures.

  18. Parking lots owned and maintained by the U.S. Fish and Wildlife Service (United States)

    US Fish and Wildlife Service, Department of the Interior — U.S. Fish and Wildlife Service parking lot inventory includes parking lots owned and maintained by the U.S. Fish and Wildlife Service on National Wildlife Refuges,...

  19. Novel role of p53 in maintaining mitochondrial genetic stability through interaction with DNA Pol γ

    National Research Council Canada - National Science Library

    Pelicano, Helene; Keating, Michael J; Feng, Li; Huang, Peng; Lu, Weiqin; Carew, Jennifer S; Achanta, Geetha; Sasaki, Ryohei


    .... Here, we report that the tumor suppressor molecule p53 has a novel role in maintaining mitochondrial genetic stability through its ability to translocate to mitochondria and interact with mtDNA polymerase γ (pol γ...

  20. Testosterone replacement maintains smooth muscle content in the corpus cavernosum of orchiectomized rats

    Directory of Open Access Journals (Sweden)

    Graziele Halmenschlager


    Conclusion: Normal testosterone levels maintain CC smooth muscle content and do not influence elastic fibers, collagen content and apoptotic index. Further studies should be performed in order to investigate the mechanisms by which androgen mediates its effects on CC structure.

  1. Teacher collaborative curriculum design in technical vocational colleges: a strategy for maintaining curriculum consistency?

    NARCIS (Netherlands)

    Albashiry, N.M.; Voogt, J.M.; Pieters, J.M.


    The Technical Vocational Education and Training (TVET) curriculum requires continuous renewal and constant involvement of stakeholders in the redesign process. Due to a lack of curriculum design expertise, TVET institutions in developing contexts encounter challenges maintaining and advancing the

  2. Stimulating and maintaining students’ interest in Computer Science using the hackathon model

    CSIR Research Space (South Africa)

    Mtsweni, J


    Full Text Available and maintain students’ interest in CS. The key elements of the hackathon model are collaborations, networking, mentoring, hands-on engagement in socially-relevant computing projects, and community involvement. The model was evaluated using expert reviews...

  3. The effects of response cost in the treatment of aberrant behavior maintained by negative reinforcement.


    Keeney, K M; Fisher, W W; Adelinis, J D; Wilder, D A


    Positive reinforcement contingencies can sometimes be used to decrease problem behavior maintained by negative reinforcement (e.g., escape). In the current study, we evaluated the extent to which response cost (i.e., contingent removal of a preferred stimulus) would compete with the negative reinforcer maintaining destructive behavior. The response cost contingency reduced destructive behavior by 87% from baseline levels even though the negative reinforcement contingency (i.e., escape) remain...

  4. Assessment of Geant4 Maintainability with respect to software engineering references (United States)

    Ronchieri, Elisabetta; Grazia Pia, Maria; Canaparo, Marco


    Over time computer scientists have been provided metrics to measure software maintainability. In existing literature, a large number of references can be found about this topic; nevertheless, a lack of quantitative assessment of maintainability metrics has been observed. In this paper, we summarize the challenges of adopting code measurements in the context of physics software system. In this pilot study, we have used Geant4 - a twenty-year-old software system - to conduct this research and set the grounds for further discussion.

  5. A Polarization Maintaining Filter based on a Liquid-Crystal-Photonic-Bandgap-Fiber

    DEFF Research Database (Denmark)

    Scolari, Lara; Olausson, Christina Bjarnal Thulin; Turchinovich, Dmitry


    A polarization maintaining filter based on a liquid-crystal-photonic-bandgap-fiber is demonstrated. Its polarization extinction ratio is 14 dB at 1550 nm. Its tunability is 150 nm.......A polarization maintaining filter based on a liquid-crystal-photonic-bandgap-fiber is demonstrated. Its polarization extinction ratio is 14 dB at 1550 nm. Its tunability is 150 nm....

  6. Frequency-dependent selection maintains clonal diversity in an asexual organism


    Weeks, Andrew R.; Hoffmann, Ary A.


    Asexual organisms can be genetically variable and evolve through time, yet it is not known how genetic diversity is maintained in populations. In sexual organisms, negative frequency-dependent selection plays a role in maintaining diversity at some loci, but in asexual organisms, this mechanism could provide a general explanation for persistent genetic diversity because it acts on the whole genome and not just on some polymorphisms within a genome. Using field manipulations, we show that nega...

  7. Dolphins Can Maintain Vigilant Behavior through Echolocation for 15 Days without Interruption or Cognitive Impairment


    Branstetter, Brian K.; Finneran, James J.; Elizabeth A Fletcher; Weisman, Brian C.; Sam H Ridgway


    In dolphins, natural selection has developed unihemispheric sleep where alternating hemispheres of their brain stay awake. This allows dolphins to maintain consciousness in response to respiratory demands of the ocean. Unihemispheric sleep may also allow dolphins to maintain vigilant states over long periods of time. Because of the relatively poor visibility in the ocean, dolphins use echolocation to interrogate their environment. During echolocation, dolphin produce clicks and listen to retu...

  8. PTM Along Track Algorithm to Maintain Spacing During Same Direction Pair-Wise Trajectory Management Operations (United States)

    Carreno, Victor A.


    Pair-wise Trajectory Management (PTM) is a cockpit based delegated responsibility separation standard. When an air traffic service provider gives a PTM clearance to an aircraft and the flight crew accepts the clearance, the flight crew will maintain spacing and separation from a designated aircraft. A PTM along track algorithm will receive state information from the designated aircraft and from the own ship to produce speed guidance for the flight crew to maintain spacing and separation

  9. Motivation to maintain sobriety among residents of sober living recovery homes


    Polcin DL; Korcha R


    Douglas L Polcin, Rachael KorchaAlcohol Research Group, Public Health Institute, Emeryville, CA, USABackground: The study of motivation in the substance abuse field has typically examined the extent to which substance users want to quit or reduce substance use. Less frequently examined is the desire to maintain sobriety after achieving abstinence. The current study examined motivation to maintain sobriety among residents of sober living houses (SLHs), a type of recovery home for individuals w...

  10. Dolphins can maintain vigilant behavior through echolocation for 15 days without interruption or cognitive impairment.

    Directory of Open Access Journals (Sweden)

    Brian K Branstetter

    Full Text Available In dolphins, natural selection has developed unihemispheric sleep where alternating hemispheres of their brain stay awake. This allows dolphins to maintain consciousness in response to respiratory demands of the ocean. Unihemispheric sleep may also allow dolphins to maintain vigilant states over long periods of time. Because of the relatively poor visibility in the ocean, dolphins use echolocation to interrogate their environment. During echolocation, dolphin produce clicks and listen to returning echoes to determine the location and identity of objects. The extent to which individual dolphins are able to maintain continuous vigilance through this active sense is unknown. Here we show that dolphins may continuously echolocate and accurately report the presence of targets for at least 15 days without interruption. During a total of three sessions, each lasting five days, two dolphins maintained echolocation behaviors while successfully detecting and reporting targets. Overall performance was between 75 to 86% correct for one dolphin and 97 to 99% correct for a second dolphin. Both animals demonstrated diel patterns in echolocation behavior. A 15-day testing session with one dolphin resulted in near perfect performance with no significant decrement over time. Our results demonstrate that dolphins can continuously monitor their environment and maintain long-term vigilant behavior through echolocation.

  11. Initiating and maintaining recreational walking: a longitudinal study on the influence of neighborhood green space. (United States)

    Sugiyama, Takemi; Giles-Corti, Billie; Summers, Jacqui; du Toit, Lorinne; Leslie, Eva; Owen, Neville


    This study examined prospective relationships of green space attributes with adults initiating or maintaining recreational walking. Postal surveys were completed by 1036 adults living in Adelaide, Australia, at baseline (two time points in 2003-04) and follow-up (2007-08). Initiating or maintaining recreational walking was determined using self-reported walking frequency. Green space attributes examined were perceived presence, quality, proximity, and the objectively measured area (total and largest) and number of green spaces within a 1.6 km buffer drawn from the center of each study neighborhood. Multilevel regression analyses examined the odds of initiating or maintaining walking separately for each green space attribute. At baseline, participants were categorized into non-regular (n = 395), regular (n = 286), and irregular walkers (n = 313). Among non-regular walkers, 30% had initiated walking, while 70% of regular walkers had maintained walking at follow-up. No green space attributes were associated with initiating walking. However, positive perceptions of the presence of and proximity to green spaces and the total and largest areas of green space were significantly associated with a higher likelihood of walking maintenance over four years. Neighborhood green spaces may not assist adults to initiate walking, but their presence and proximity may facilitate them to maintain recreational walking over time. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Neurophysiological and biochemical properties of the goldfish optic tectum maintained in vitro. (United States)

    Teyler, T J; Lewis, D; Shashoua, V E


    The physiology and biochemistry of the in vitro goldfish optic tectum are examined. Following surgical removal of the intact optic tectum by severing its connectives, the tectal explant is maintained in a brain slice chamber in a specified medium for up to 24 hours. Electrophysiological studies show that the in vitro tectum displays the same response properties to optic nerve stimulation as does an in vivo tectum. Concurrent biochemical studies that RNA and protein synthesis is actively maintained for at least 17 hrs in vitro. Thus both biochemical and electrophysiological measurements indicate that the integrity of the tectal explant can be maintained in vitro making it a suitable model system for investigations of a variety of neurobiological questions.

  13. Sustained levels of FGF2 maintain undifferentiated stem cell cultures with biweekly feeding.

    Directory of Open Access Journals (Sweden)

    Steven Lotz

    Full Text Available An essential aspect of stem cell culture is the successful maintenance of the undifferentiated state. Many types of stem cells are FGF2 dependent, and pluripotent stem cells are maintained by replacing FGF2-containing media daily, while tissue-specific stem cells are typically fed every 3rd day. Frequent feeding, however, results in significant variation in growth factor levels due to FGF2 instability, which limits effective maintenance due to spontaneous differentiation. We report that stabilization of FGF2 levels using controlled release PLGA microspheres improves expression of stem cell markers, increases stem cell numbers and decreases spontaneous differentiation. The controlled release FGF2 additive reduces the frequency of media changes needed to maintain stem cell cultures, so that human embryonic stem cells and induced pluripotent stem cells can be maintained successfully with biweekly feedings.

  14. Recommendations to the NRC on human engineering guidelines for nuclear power plant maintainability

    Energy Technology Data Exchange (ETDEWEB)

    Badalamente, R.V.; Fecht, B.A.; Blahnik, D.E.; Eklund, J.D.; Hartley, C.S.


    This document contains human engineering guidelines which can enhance the maintainability of nuclear power plants. The guidelines have been derived from general human engineering design principles, criteria, and data. The guidelines may be applied to existing plants as well as to plants under construction. They apply to nuclear power plant systems, equipment and facilities, as well as to maintenance tools and equipment. The guidelines are grouped into seven categories: accessibility and workspace, physical environment, loads and forces, maintenance facilities, maintenance tools and equipment, operating equipment design, and information needs. Each chapter of the document details specific maintainability problems encountered at nuclear power plants, the safety impact of these problems, and the specific maintainability design guidelines whose application can serve to avoid these problems in new or existing plants.

  15. Reliability and Maintainability model (RAM) user and maintenance manual. Part 2 (United States)

    Ebeling, Charles E.


    This report documents the procedures for utilizing and maintaining the Reliability and Maintainability Model (RAM) developed by the University of Dayton for the NASA Langley Research Center (LaRC). The RAM model predicts reliability and maintainability (R&M) parameters for conceptual space vehicles using parametric relationships between vehicle design and performance characteristics and subsystem mean time between maintenance actions (MTBM) and manhours per maintenance action (MH/MA). These parametric relationships were developed using aircraft R&M data from over thirty different military aircraft of all types. This report describes the general methodology used within the model, the execution and computational sequence, the input screens and data, the output displays and reports, and study analyses and procedures. A source listing is provided.

  16. Caffeine delays oocyte aging and maintains the quality of aged oocytes safely in mouse. (United States)

    Zhang, Xia; Liu, Xiaoyan; Chen, Li; Wu, Dan-Ya; Nie, Zheng-Wen; Gao, Ying-Ying; Miao, Yi-Liang


    Caffeine, as an oocyte aging inhibitor, was used in many different species to control or delay oocyte aging. However, the safety of caffeine and developmental competence of aged oocytes inhibited by caffeine has not been studied systematically. So we detected the spindle morphology, distribution of cortical granules, zona pellucida hardening and pronucleus formation to assess oocyte quality of caffeine treated oocytes. We found that aged oocytes treated by caffeine maintained weak susceptibility to activating stimuli and regained normal competent after aged further 6 hr. Caffeine maintained the spindle morphology, changed cortical granules distribution of aged oocytes and could not prevent zona pellucida hardening. Furthermore, caffeine increased pronucleus formation of aged oocytes and decreased fragmentation after fertilization. These results suggested that caffeine could maintain the quality of aged oocytes safely in mouse.

  17. Fetal rat sympathetic neurons maintained in a serum-free medium retain induced cholinergic characteristics. (United States)

    Higgins, D; Iacovitti, L; Burton, H


    When maintained in some serum-containing media, fetal rat sympathetic neurons acquire substantial choline acetyltransferase activity and form cholinergic synapses in vitro. However, when they are maintained in a serum-free, defined culture medium, choline acetyltransferase activity is not detected and cholinergic synapses are not observed. In this study, we have examined the effects of various times of exposure to a medium inducing cholinergic function on the properties of neurons subsequently maintained in defined medium. We report that 2-day, but not 2-h, exposure to this inducing medium causes a long-lasting (greater than 6 weeks) increase (7-10-fold) in the activity of choline acetyltransferase and that, under these conditions, sympathetic neurons in vitro form cholinergic, electrical and mixed function cholinergic and electrical synapses. We conclude that a relatively brief exposure to media inducing cholinergic function can cause long-lasting changes in the functional properties of sympathetic neurons in vitro.

  18. Kekuatan Geser dan Pola Patahan Loop Space Maintainer yang Dibuat dengan Teknik Spot Welding Elektrik

    Directory of Open Access Journals (Sweden)

    Elin Karlina


    Full Text Available The aim of this research was to study the effect of spot variations on shear strength of spot welds in an electric loop space maintainer. Stainless steel wire of 0.8 mm diameter and nickel chromium crwon for lower second molar of temporary teeth were used. A loop 1 cm wide, made of 3.5 cm stainless steel wire, was welded with 3 dots on the crown using an electric spot welder. Each dot for each group took different spot variations from 1 X – 4 X. A loop space maintainer made with the usual materials and techniques as applied at the IKGA FKG UI Clinic was used as a control, with a torch as heat source. Ten specimens each were prepared for shear testing and three spesimens each for metallography. Universal testing machine was used for shear strength testing at a crosshead speed of 0.5 mm/min, and SEM/EDS was used for metallography and fractography. The data were statistically analyzed with one-way ANOVA at p = 0.05, and Tukey post hoc test. The results show that the shear strength of the welded loop space maintainer was higher than that of a soldered loop space maintainer, although the difference was not statistically significant with spot variation 1 X. SEM/EDS analysis suggests that a new alloy forms at the contact area of welded and soldered loop space maintainer. Fractography of the joints suggests that welds are better than soldered joints, with higher ductility and toughness, as can be seen from the dimpled pattern of the welded joint and cleavage patterns in the control joints. In conclusion, the loop space maintainer is better made by welding than by soldering.

  19. Interleukin 17A controls Interleukin 17F production and maintains blood neutrophil counts in mice


    von Vietinghoff, Sibylle; Ley, Klaus


    Granulocyte colony-stimulating factor (G-CSF), its receptor and interleukin-17 receptor A (IL-17RA) are all required to maintain baseline neutrophil counts in mice. Here, we tested whether IL-17F could compensate and maintain baseline neutrophil counts in the absence of IL-17A. Unlike the reduced neutrophil counts found in IL-17RA deficient mice, neutrophil counts were mildly increased in IL-17A deficient (Il17a-/-) animals. There was no evidence for infection or altered neutrophil function. ...

  20. Reliability and Maintainability Model (RAM): User and Maintenance Manual. Part 2; Improved Supportability Analysis (United States)

    Ebeling, Charles E.


    This report documents the procedures for utilizing and maintaining the Reliability & Maintainability Model (RAM) developed by the University of Dayton for the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC). The purpose of the grant is to provide support to NASA in establishing operational and support parameters and costs of proposed space systems. As part of this research objective, the model described here was developed. This Manual updates and supersedes the 1995 RAM User and Maintenance Manual. Changes and enhancements from the 1995 version of the model are primarily a result of the addition of more recent aircraft and shuttle R&M data.

  1. Engineering reliability and maintainability review - A regimen for discovering production deficiencies (United States)

    McKelvey, Michael H.; Babin, Robert S.

    An engineering reliability and maintainability review (ER&MR) is a methodical disassembly, visual inspection, and physical examination of a production unit of airborne equipment by a team of reviewers from reliability, maintainability, and other technical disciplines. Established at Douglas Aircraft for the DC-10 program and recently upgraded, ER&MR facilitates detection of unit design and assembly flaws and deficiencies that traditional design reviews and inspections may fail to discover. ER&MR also verifies required circuit separation and segregation in the unit and incorporation of unit design changes authorized by the critical design review team.

  2. Sharing the sandbox: Evolutionary mechanisms that maintain bacterial cooperation [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Eric Bruger


    Full Text Available Microbes are now known to participate in an extensive repertoire of cooperative behaviors such as biofilm formation, production of extracellular public-goods, group motility, and higher-ordered multicellular structures. A fundamental question is how these cooperative tasks are maintained in the face of non-cooperating defector cells. Recently, a number of molecular mechanisms including facultative participation, spatial sorting, and policing have been discovered to stabilize cooperation. Often these different mechanisms work in concert to reinforce cooperation. In this review, we describe bacterial cooperation and the current understanding of the molecular mechanisms that maintain it.

  3. Phase sensitivity to temperature of the guiding mode in polarization-maintaining photonic crystal fiber. (United States)

    Song, Jingming; Sun, Kang; Li, Shuai; Cai, Wei


    The propagating phase changing of a polarization-maintaining photonic crystal fiber (PM-PCF) caused by temperature variation is theoretically studied, as well as compared with conventional PANDA fiber. As to verifying numerical analysis, a platform based on a Michelson interferometer for phase versus temperature measurement was built for both kinds of fiber. Experiments show that PM-PCF has similar temperature sensitivity with conventional polarization-maintaining fiber. With optimized PM-PCF design (thinner coating layer and coating material with smaller thermal expansion coefficient), the sensitivity could be further reduced to about 80% of the present level.

  4. Maintaining Arc Consistency in Non-Binary Dynamic CSPs using Simple Tabular Reduction

    DEFF Research Database (Denmark)

    Queva, Matthieu Stéphane Benoit; Probst, Christian W.; Ricci, Laurent


    CSPs use filtering techniques such as arc consistency, which also have been adapted to handle DCSPs with binary constraints. However, there exists only one algorithm targeting non-binary DCSPs (DnGAC4). In this paper we present a new algorithm DnSTR for maintaining arc consistency in DCSPs with non......-binary constraints. Our algorithm is based on Simple Tabular Reduction for Table Constraints, a technique that dynamically maintains the tables of supports within the constraints. Initial results show that our algorithm outperforms DnGAC4 both for addition and removal of constraints....

  5. Maintaining Work: The Influence of Child Care Subsidies on Child Care-Related Work Disruptions (United States)

    Forry, Nicole D.; Hofferth, Sandra L.


    With the passage of welfare reform, support for low-income parents to not only obtain but also maintain work has become imperative. The role of child care subsidies in supporting parents' job tenure has received little attention in the literature. This article examines the association between receiving a child care subsidy and experiencing a child…

  6. 30 CFR 250.109 - What documents must I prepare and maintain related to welding? (United States)


    ... related to welding? 250.109 Section 250.109 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF... Performance Standards § 250.109 What documents must I prepare and maintain related to welding? (a) You must submit a Welding Plan to the District Manager before you begin drilling or production activities on a...

  7. Hanford Site guide for preparing and maintaining generator group pollution prevention program documentation

    Energy Technology Data Exchange (ETDEWEB)

    Place, B. G.


    This document provides guidance to contractor generator groups for developing and maintaining documentation of Pollution Prevention/Waste. Minimization (P2/WMin) Program activities. The program documentation is intended to demonstrate generator compliance with U.S. Department of Energy (DOE) requirements as well as state and Federal regulations.

  8. Self-starting self-similar all-polarization maintaining Yb-doped fiber laser. (United States)

    Nielsen, C; Ortaç, B; Schreiber, T; Limpert, J; Hohmuth, R; Richter, W; Tünnermann, A


    We report on the generation of self-similar pulses from an self-starting saturable absorber mirror (SAM) based environmentally stable fiber laser comprising only polarization maintaining (PM) fibers. Pulse energies of 1 nJ at a repetition rate of 17 MHz were obtained, which could be externally compressed to an autocorrelation width of 280 fs.

  9. Self-starting self-similar all-polarization maintaining Yb-doped fiber laser


    Nielsen, C.; Ortac, B.; Schreiber, T.; Limpert, J.; Hohmuth, R.; Richter, W.; Tünnermann, A.


    We report on the generation of self-similar pulses from an self-starting saturable absorber mirror (SAM) based environmentally stable fiber laser comprising only polarization maintaining (PM) fibers. Pulse energies of 1 nJ at a repetition rate of 17 MHz were obtained, which could be externally compressed to an autocorrelation width of 280 fs.

  10. 9 CFR 201.29 - Market agencies, packers and dealers required to file and maintain bonds. (United States)


    ... REGULATIONS UNDER THE PACKERS AND STOCKYARDS ACT Market Agency, Dealer and Packer Bonds § 201.29 Market agencies, packers and dealers required to file and maintain bonds. (a) Every market agency, packer, and... effect a bond complying with the regulations in this part. (b) Every market agency buying on a commission...

  11. An Approach for Maintaining Models of an E-Commerce Collaboration

    NARCIS (Netherlands)

    Bodenstaff, L.; Wombacher, Andreas; Reichert, M.U.; Wieringa, Roelf J.

    To keep an overview on complex E-Commerce collaborations several models are used to describe them. When models overlap in describing a collaboration, the overlapping information should not contradict. Models are of different nature and maintained by different people. Therefore, keeping model-overlap

  12. Assessing bioenergy harvest risks: Geospatially explicit tools for maintaining soil productivity in western US forests (United States)

    Mark Kimsey; Deborah Page-Dumroese; Mark Coleman


    Biomass harvesting for energy production and forest health can impact the soil resource by altering inherent chemical, physical and biological properties. These impacts raise concern about damaging sensitive forest soils, even with the prospect of maintaining vigorous forest growth through biomass harvesting operations. Current forest biomass harvesting research...

  13. Maintaining and restoring sustainable ecosystems in southern Nevada [Chapter 7] (Executive Summary) (United States)

    Jeanne C. Chambers; Burton K. Pendleton; Donald W. Sada; Steven M. Ostoja; Matthew L.. Brooks


    Resource managers in southern Nevada are faced with the challenge of determining appropriate goals and objectives and developing viable approaches for maintaining and restoring sustainable ecosystems in the face of rapid socio-ecological and environmental change. Many of southern Nevada’s ecosystems are being subjected to anthropogenic stressors that span global,...

  14. Worms Eat My Garbage. How To Set Up and Maintain a Worm Composting System. First Edition. (United States)

    Appelhof, Mary

    This book is a resource for parents and teachers who want to teach about recycling and composting by setting up and maintaining a worm composting system. It is designed to be a detailed yet simple manual of vermicomposting. The manual covers the basics of vermicomposting and answers such questions as where to store a composting container, what…

  15. Maintaining Partial Path Consistency in STNs under Event-Incremental Updates

    NARCIS (Netherlands)

    Ten Thije, O.; Planken, L.R.; De Weerdt, M.M.


    Efficient management of temporal constraints is important for temporal planning. During plan development, many solvers employ a heuristic-driven backtracking approach, over the course of which they maintain a so-called Simple Temporal Network (STN) of events and constraints. This paper presents the

  16. Creating and Maintaining Student Diversity: Strategies and Challenges for School Leaders (United States)

    Villavicencio, Adriana


    The purpose of this paper was to explore how school leaders can create and maintain student diversity in charter schools. Based on a case study of two racially balanced schools in New York City, this study identifies three strategies that the schools' leaders took to create more student diversity: (1) develop curriculum-centred missions, (2)…

  17. Maintaining Curriculum Consistency of Technical and Vocational Educational Programs through Teacher Design Teams

    NARCIS (Netherlands)

    Albashiry, Nabeel; Voogt, Joke; Pieters, Julius Marie


    Maintaining the quality and relevance of Technical Vocational Education and Training (TVET) curricula is a great challenge for TVET institutions in developing countries. One major challenge lies in the lack of curriculum design expertise of TVET academics. The purpose of this multiplecase study is

  18. Beaver dams maintain fish biodiversity by increasing habitat heterogeneity throughout a low-gradient stream network (United States)

    Smith, Joseph M.; Mather, Martha E.


    Understanding the relationship between heterogeneity and biodiversity is an active focus of ecological research. Although habitat heterogeneity is conceptually linked to biodiversity, the amount and configuration of heterogeneity that maintains biodiversity within ecosystems is not well understood, especially for an entire stream network.


    Directory of Open Access Journals (Sweden)

    A. A. Itskovich


    Full Text Available The article presents the results of research on the analysis of logistic support processes of maintaining of the aircraft (AC airworthiness (AW, the solution of problems of scientific and methodological support: analysis of logistics support and formation of an integrated logistics support (ILS.

  20. 25 CFR 900.53 - What kind of records shall the property management system maintain? (United States)


    ... 25 Indians 2 2010-04-01 2010-04-01 false What kind of records shall the property management system... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.53 What kind of records shall the property management system maintain? The...

  1. Configuration maintaining control of three-body ring tethered system based on thrust compensation (United States)

    Huang, Panfeng; Liu, Binbin; Zhang, Fan


    Space multi-tethered systems have shown broad prospects in remote observation missions. This paper mainly focuses on the dynamics and configuration maintaining control of space spinning three-body ring tethered system for such mission. Firstly, we establish the spinning dynamic model of the three-body ring tethered system considering the elasticity of the tether using Newton-Euler method, and then validate the suitability of this model by numerical simulation. Subsequently, LP (Likins-Pringle) initial equilibrium conditions for the tethered system are derived based on rigid body's equilibrium theory. Simulation results show that tether slack, snapping and interaction between the tethers exist in the three-body ring system, and its' configuration can not be maintained without control. Finally, a control strategy based on thrust compensation, namely thrust to simulate tether compression under LP initial equilibrium conditions is designed to solve the configuration maintaining control problem. Control effects are verified by numerical simulation compared with uncontrolled situation. Simulation results show that the configuration of the three-body ring tethered system could maintain under this active control strategy.

  2. Designing a Maintainable and Sustainable Coast Guard Icebreaker for Arctic and Antarctic Operations (United States)


    and other chemical waste products that will have to follow a specific storage plan. The ability to dispose of waste is imperative to maintain...or pulping . The Coast Guard will have to select one of these methods, similar to those used onboard U.S. Navy vessels [9]. This mandatory

  3. Towards a benchmark for the maintainability evolution of industrial software systems

    NARCIS (Netherlands)

    Dohmen, Till; Bruntink, Magiel; Ceolin, Davide; Visser, Joost


    The maintainability of software is an important cost factor for organizations across all industries, as maintenance makes up approximately 40% to 70% of the total development costs of a software system. Organizations are often stuck in the situation where software maintenance costs dominate IT

  4. Self-Reinforcement and Descriptive Praise in Maintaining Token Economy Reading Performance. (United States)

    Novak, Gary; Hammond, J. Mark


    Researchers used four token reinforcement systems--tokens only, descriptive praise, self-reinforcement, and a combination of all three--and observed the effect on the problem solving performance of fourth-grade reading students. Only students using the combination reward system maintained their progress after tokens were withdrawn. (Authors/PP)

  5. The Effects of Presession Manipulations on Automatically Maintained Challenging Behavior and Task Responding (United States)

    Chung, Yi-Chieh; Cannella-Malone, Helen I.


    This study examined the effects of presession exposure to attention, response blocking, attention with response blocking, and noninteraction conditions on subsequent engagement in automatically maintained challenging behavior and correct responding in four individuals with significant intellectual disabilities. Following a functional analysis, the…

  6. Digital Avionics Information System (DAIS): Reliability and Maintainability Model. Final Report. (United States)

    Czuchry, Andrew J.; And Others

    The reliability and maintainability (R&M) model described in this report represents an important portion of a larger effort called the Digital Avionics Information System (DAIS) Life Cycle Cost (LCC) Study. The R&M model is the first of three models that comprise a modeling system for use in LCC analysis of avionics systems. The total…

  7. Maintaining Participation and Momentum in Longitudinal Research Involving High-Risk Families (United States)

    Graziotti, Ann L.; Hammond, Jane; Messinger, Daniel S.; Bann, Carla M.; Miller-Loncar, Cynthia; Twomey, Jean E.; Bursi, Charlotte; Woldt, Eunice; Nelson, Jay Ann; Fleischmann, Debra; Alexander, Barbara


    Purpose The purpose of the current study was to identify and describe strategies available to optimize retention of a high-risk research cohort and assist in the recovery of study participants following participant dropout. Design and Methods The Maternal Lifestyle Study (MLS), which investigated the effects of prenatal substance exposure (cocaine or opiates) on child outcome, is a prospective longitudinal follow-up study that extended from birth through 15 years of age. Retention strategies to maximize participation and factors that might negatively impact compliance were examined over the course of five follow-up phases. Findings At the conclusion of the 15-year visits, MLS had successfully maintained compliance at 76%. Retention rates did not differ by exposure group. Conclusions Maintaining ongoing participation of enrolled study subjects is a critical element of any successful longitudinal study. Strategies that can be used to reengage and maintain participants in longitudinal research include persistence, flexibility with scheduling, home visits, long-distance trips, increased incentives, and development of a computerized tracking system. Establishing rapport with families and ensuring confidentiality contributed to overall participant retention. The use of multiple tracking techniques is essential. Clinical Relevance Researchers are challenged to maintain participants in longitudinal studies to ensure the integrity of their research. PMID:22458928

  8. Ties That Bind: Building and Maintaining Strong Parent-Child Relationships through Family Traditions and Rituals. (United States)

    Franklin, Diane, Ed.; Bankston, Karen, Ed.

    This booklet discusses the importance of family rituals as a way of staying connected to children as they move through adolescence. Family rituals give teens a sense of being part of a family that values its time together. Even something as simple as a family meal together can have great impact on maintaining a bond between parents and children.…

  9. Maintaining Health and Safety at Workplace: Employee and Employer's Role in Ensuring a Safe Working Environment (United States)

    Jonathan, Grace Katunge; Mbogo, Rosemary Wahu


    The concern for health and safety is legitimate in every context of human enterprise. In schools, for teaching staff's safety to be guaranteed, the equipment available should be properly maintained and installation for nonexistent ones done according to the health and safety policies. With a focus on Mbooni West district, this paper reports the…

  10. Treatment of Escape-Maintained Behavior with Positive Reinforcement: The Role of Reinforcement Contingency and Density (United States)

    Ingvarsson, Einar T.; Hanley, Gregory P.; Welter, Katherine M.


    Functional analyses suggested that the disruptive behavior of three preschool children was maintained by escape from demands. While keeping the escape contingency intact, we conducted (a) a density analysis in which the children earned preferred items for task completion according to two schedules that varied in reinforcement density, and (b) a…

  11. Metabolic and hemodynamic effects of saline infusion to maintain volemia on temporary abdominal aortic occlusion

    Directory of Open Access Journals (Sweden)

    Fábio Ferreira Amorim


    Full Text Available OBJECTIVE: To analyze hemodynamic and metabolic effects of saline solution infusion in the maintenance of blood volume in ischemia-reperfusion syndrome during temporary abdominal aortic occlusion in dogs. METHODS: We studied 20 dogs divided into 2 groups: the ischemia-reperfusion group (IRG, n=10 and the ischemia-reperfusion group with saline solution infusion aiming at maintaining mean pulmonary arterial wedge pressure between 10 and 20 mmHg (IRG-SS, n=10. All animals were anesthetized with sodium thiopental and maintained on spontaneous ventilation. Occlusion of the supraceliac aorta was obtained with inflation of a Fogarty catheter inserted through the femoral artery. After 60 minutes of ischemia, the balloon was deflated, and the animals were observed for another 60 minutes of reperfusion. RESULTS: IRG-SS dogs did not have hemodynamic instability after aortic unclamping, and the mean systemic blood pressure and heart rate were maintained. However, acidosis worsened, which was documented by a greater reduction of arterial pH that occurred especially due to the absence of a respiratory response to metabolic acidosis that was greater with the adoption of this procedure. CONCLUSION: Saline solution infusion to maintain blood volume avoided hemodynamic instability after aortic unclamping. This procedure, however, caused worsening in metabolic acidosis in this experimental model.

  12. We're All Adults Here: Clarifying and Maintaining Boundaries with Adult Learners (United States)

    Booth, Melanie; Schwartz, Harriet L.


    Working with adult learners presents a unique set of interpersonal boundary questions. In this chapter, the authors discuss the characteristics of working with adult learners that have led them to explore questions about boundaries between them and their students. They then identify how they might define, set, maintain, adjust, and work close to…

  13. Do African American women require fewer calories to maintain weight?: Results from a controlled feeding trial. (United States)

    Brewer, Laprincess C; Miller, Edgar R; Appel, Lawrence J; Anderson, Cheryl A M


    The high prevalence of obesity in African American (AA) women may result, in part, from a lower resting metabolic rate (RMR) than non-AA women. If true, AA women should require fewer calories than non-AA women to maintain weight. Our objective was to determine in the setting of a controlled feeding study, if AA women required fewer calories than non-AA women to maintain weight. This analysis includes 206 women (73% AA), aged 22-75 years, who participated in the Dietary Approaches to Stop Hypertension (DASH) trial-a multicenter, randomized, controlled, feeding study comparing the effects of 3 dietary patterns on blood pressure in individuals with prehypertension or stage 1 hypertension. After a 3-week run-in, participants were randomized to 1 of 3 dietary patterns for 8 weeks. Calorie intake was adjusted during feeding to maintain stable weight. The primary outcome of this analysis was average daily calorie (kcal) intake during feeding. AA women had higher baseline weight and body mass index than non-AA women (78.4 vs 72.4 kg, P calories to maintain weight.

  14. Maintaining a permanent plot data base for growth and yield research: Solutions to some recurring problems (United States)

    John C. Byrne


    Methods for solving some recurring problems of maintaining a permanent plot data base for growth and yield reseuch are described. These methods include documenting data from diverse sampling designs, changing sampling designs, changing field procedures, and coordinating activities in the plots with the land management agency. Managing a permanent plot data base (...

  15. 21 CFR 1.352 - What information must transporters establish and maintain? (United States)


    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false What information must transporters establish and maintain? 1.352 Section 1.352 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... and transporter's immediate subsequent recipient; (2) Origin and destination points; (3) Date shipment...

  16. Femtosecond all-polarization-maintaining fiber laser operating at 1028 nm

    DEFF Research Database (Denmark)

    Olsson, R.K.; Andersen, T.V.; Leick, Lasse


    We present an effective solution for an all-polarization-maintaining modelocked femtosecond fiber laser operating at the central wavelength of 1028 nm. The laser is based on an Yb-doped active fiber. Modelocking is enabled by a semiconductor saturable absorber mirror, and the central wavelength...

  17. Isodicentric Y Chromosomes and Sex Disorders as Byproducts of Homologous Recombination that Maintains Palindromes

    NARCIS (Netherlands)

    Lange, Julian; Skaletsky, Helen; van Daalen, Saskia K. M.; Embry, Stephanie L.; Korver, Cindy M.; Brown, Laura G.; Oates, Robert D.; Silber, Sherman; Repping, Sjoerd; Page, David C.


    Massive palindromes in the human Y chromosome harbor mirror-image gene pairs essential for spermatogenesis. During evolution, these gene pairs have been maintained by intrapalindrome, arm-to-arm recombination. The mechanism of intrapalindrome recombination and risk of harmful effects are unknown. We

  18. Setting apart the amateur from the professional: maintaining the value of standardised representational photography. (United States)

    Banks, Debbie


    The purpose of this paper is to discuss the importance of standard representational photography in clinical photography and its aid in maintaining the gold standard in the medical illustration profession. it is important that professionals are aware of potential threats to good practice with many areas identified in the article.

  19. Definition and means of maintaining the effluent stack monitors portion of the PFP safety envelope

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, P.J.


    The Effluent Stack Monitors ensure that the release of alpha emitting radionuclides to the environment via the building exhaust stacks is continuously monitored and alarms are initiated if the release exceeds identified limits. This document defines the safety envelope for the Effluent Stack Monitors and identifies the operability requirements, components, and procedures which ensure this safety envelope is maintained.

  20. Thermal element for maintaining minimum lamp wall temperature in fluorescent fixtures (United States)

    Siminovitch, Michael J.


    In a lighting fixture including a lamp and a housing, an improvement is disclosed for maintaining a lamp envelope area at a cooler, reduced temperature relative to the enclosed housing ambient. The improvement comprises a thermal element in thermal communication with the housing extending to and springably urging thermal communication with a predetermined area of the lamp envelope surface.

  1. Next Generation Enterprise Network Business Continuity: Maintaining Operations In A Compromised Environment (United States)


    ENTERPRISE NETWORK BUSINESS CONTINUITY: MAINTAINING OPERATIONS IN A COMPROMISED ENVIRONMENT by Erik C. Hansen March 2016 Thesis mission resilience and mission assurance engineering [2], [24]. This work explores business continuity in a compromised environment ...are commercially available and are developed by mature companies. Cisco offers collaboration tailored to virtual environments as part of Business

  2. An examination of the psycho-social factors maintaining a persistent ...

    African Journals Online (AJOL)

    Introduction: A paramount attention in the national polity today, and, perhaps, cross-culturally,is that, research investigations are needed to identify and classify the multi-psychosocial factors maintaining voluntary and compulsive idleness among able bodied women. Method: Descriptive survey, in a cross-sectional format ...

  3. Evaluation of a web-based lifestyle coach designed to maintain a healthy bodyweight

    NARCIS (Netherlands)

    Kelders, Saskia Marion; van Gemert-Pijnen, Julia E.W.C.; Werkman, Andrea; Seydel, E.R.


    We evaluated a web-based intervention, the Healthy Weight Assistant (HWA), which was designed to help people with a healthy bodyweight, or those who are slightly overweight, to achieve and maintain a healthy weight. Four evaluation methods were used: (1) pre- and post-test questionnaires; (2) real

  4. Evaluation of antibiotic releasing porous polymethylmethacrylate space maintainers in an infected composite tissue defect model

    NARCIS (Netherlands)

    Spicer, P.P.; Shah, S.R.; Henslee, A.M.; Watson, B.M.; Kinard, L.A.; Kretlow, J.D.; Bevil, K.; Kattchee, L.; Bennett, G.N.; Demian, N.; Mende, K.; Murray, C.K.; Jansen, J.A.; Wong, M.E.; Mikos, A.G.; Kasper, F.K.


    This study evaluated the in vitro and in vivo performance of antibiotic-releasing porous polymethylmethacrylate (PMMA)-based space maintainers comprising a gelatin hydrogel porogen and a poly(dl-lactic-co-glycolic acid) (PLGA) particulate carrier for antibiotic delivery. Colistin was released in

  5. Reptile and amphibian responses to restoration of fire-maintained pine woodlands (United States)

    Roger W Perry; D. Craig Rudolph; Ronald E. Thill


    Fire-maintained woodlands and savannas are important ecosystems for vertebrates in many regions of the world. These ecosystems are being restored by forest managers, but little information exists on herpetofaunal responses to this restoration in areas dominated by shortleaf pine (Pinus echinata). We compared habitat characteristics and...

  6. A Swarm Intelligent Algorithm Based Route Maintaining Protocol for Mobile Sink Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiaoming Wu


    Full Text Available Recent studies have shown that mobile sink can be a solution to solve the problem that energy consumption of sensor nodes is not balanced in wireless sensor networks (WSNs. Caused by the sink mobility, the paths between the sensor nodes and the sink change frequently and have profound influence on the lifetime of WSN. It is necessary to design a protocol that can find efficient routings between the mobile sink and nodes but does not consume too many network resources. In this paper, we propose a swarm intelligent algorithm based route maintaining protocol to resolve this issue. The protocol utilizes the concentric ring mechanism to guide the route researching direction and adopts the optimal routing selection to maintain the data delivery route in mobile sink WSN. Using the immune based artificial bee colony (IABC algorithm to optimize the forwarding path, the routing maintaining protocol could find an alternative routing path quickly and efficiently when the coordinate of sink is changed in WSN. The results of our extensive experiments demonstrate that our proposed route maintaining protocol is able to balance the network traffic load and prolong the network lifetime.

  7. Male sterility of triticale lines generated through recombination of triticale and rye maintainers

    Directory of Open Access Journals (Sweden)

    Tomasz Warzecha


    Full Text Available The Triticum timopheevi cytoplasmic male sterility (cms system in triticale (xTriticosecale Wittmack suffers from a low frequency of maintainers and environmental instability of the male sterility. On the other hand, the Pampa cms system in rye (Secale cereale exhibits strong male sterility and a low frequency of restorers. Here, we report generating hybrids between maintainers of the T. timopheevi cms system in triticale and maintainers of the rye Pampa cms system. Ten hybrids were obtained. Their hybridity was verified by PCR (polymerase chain reaction using ISSR (inter simple sequence repeats primers. The cms maintaining ability of F2 individuals and their progeny was tested. The F2 plants were crossed to male sterile lines of triticale carrying the T. timopheevi cytoplasm. Among 180 G1 offspring of these crosses, 71 (39.4% were completely male sterile. Fourteen F2 individuals (7.8%, as well as their F2S1 and progeny, generated stable male sterility in G1, G1BC1 and G1BC2 generations after the crosses. Our results suggest that it is possible to produce a more stable cms system in triticale based on the T. timopheevi cytoplasm as compared to the existing one.

  8. 20 CFR 670.530 - Are Job Corps centers required to maintain a student accountability system? (United States)


    ... accountability system? Yes, each Job Corps center must establish and operate an effective system to account for... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Are Job Corps centers required to maintain a... ADMINISTRATION, DEPARTMENT OF LABOR THE JOB CORPS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Program...

  9. Failure to maintain set as a predictor of childhood depression within a children's psychiatric inpatient sample. (United States)

    Kavanaugh, Brian C; Gaudet, Charles E; Dupont-Frechette, Jennifer A; Tellock, Perrin P; Maher, Isolde D; Haisley, Lauren D; Holler, Karen A


    Despite a wealth of studies in adults and adolescents, only a handful of studies have examined executive function in childhood depression. This study utilized retrospective chart review of a children's psychiatric inpatient program to evaluate executive function via Wisconsin Card Sorting Test (WCST) in 33 children (6-12 years old) with a depressive disorder and 61 age/sex-matched children without a depressive disorder referred for neuropsychological evaluation. WCST categories, perseverative errors, and failure to maintain set errors were examined as potential predictors of depressive disorder diagnosis and self-reported depressive symptoms. After controlling for age, length of hospital stay, and ADHD, failure to maintain set significantly predicted depressive disorder diagnosis. Failure to maintain set was also significantly associated with self-reported depressive symptoms. Current findings provide preliminary evidence to suggest that failure to maintain set may reflect a core deficit of childhood depression. While findings are preliminary, this may have important implications for the diagnosis and treatment of childhood depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. KB WOT Fisheries 2018: maintaining excellence and innovation in fisheries research

    NARCIS (Netherlands)

    Damme, van C.J.G.; Verver, S.W.


    The KB WOT Fisheries programme is developed to maintain and develop expertise needed to carry out the Dutch statutory obligations in fisheries monitoring and advice. The KB WOT Fisheries programme developed for 2018 reflects the scientific and management needs of the WOT fisheries programme. The

  11. How individuals with dementia in nursing homes maintain their dignity through life storytelling - a case study. (United States)

    Heggestad, Anne Kari Tolo; Slettebø, Åshild


    The aim of this article was to present and discuss findings on what individuals with dementia do by themselves to maintain or promote their dignity of identity when they live in a nursing home. The majority of residents living in Norwegian nursing homes suffer from dementia. Individuals who suffer from dementia are particularly vulnerable, and their dignity of identity is at risk. It is therefore of great importance to explore how we can maintain their dignity of identity. The study builds on a phenomenological and hermeneutic design. The article reports three cases or life stories based on participant observation in two different nursing homes and interviews with five residents with dementia living in these nursing homes. Fifteen residents with dementia from these nursing home wards were included in the overall study. Individuals with dementia living in nursing homes may use life storytelling or narratives to manage chaos and to find safety in their lives. Storytelling is also used as a way to present and maintain identity. We can see this as a way of maintaining dignity of identity or social dignity. Life storytelling can be seen as an important way of preserving dignity for people with dementia. It is of great importance that health care professionals are open to and listen to the life stories people with dementia tell. As nurses we have an obligation to ensure that dignity is enhanced in care for people with dementia. Knowledge about how residents with dementia use life storytelling as a way to maintain dignity is therefore of great importance to health care workers in nursing homes. © 2015 John Wiley & Sons Ltd.

  12. Coupled Proliferation and Apoptosis Maintain the Rapid Turnover of Microglia in the Adult Brain

    Directory of Open Access Journals (Sweden)

    Katharine Askew


    Full Text Available Microglia play key roles in brain development, homeostasis, and function, and it is widely assumed that the adult population is long lived and maintained by self-renewal. However, the precise temporal and spatial dynamics of the microglial population are unknown. We show in mice and humans that the turnover of microglia is remarkably fast, allowing the whole population to be renewed several times during a lifetime. The number of microglial cells remains steady from late postnatal stages until aging and is maintained by the spatial and temporal coupling of proliferation and apoptosis, as shown by pulse-chase studies, chronic in vivo imaging of microglia, and the use of mouse models of dysregulated apoptosis. Our results reveal that the microglial population is constantly and rapidly remodeled, expanding our understanding of its role in the maintenance of brain homeostasis.

  13. An economic perspective on software licenses--open source, maintainers and user-developers

    DEFF Research Database (Denmark)

    Edwards, Kasper


    This paper presents a model for understanding behaviour of agents using and/or contributing to open source software. The model illustrates behaviour of agents under three licenses regimes: 1) The GPL, The BSD and 3) The Microsoft EULA. The latter license is not an open source license...... and is included as both a reference and as an example of a general situation where users do not contribute source code. The model is uses economic theory of externalities and opportunity cost as a measure of agents' costs. The basic premise is that agents will only participate in development if there is a net...... benefit. Agents are divided into firms and individuals, which can be either maintainer or user-developers. A maintainer is an agent responsible for releasing new versions of a program and a user-developer is an agent who use but may also become a developer. It is observed through the model that the three...

  14. Minimum recommended physical activity, and perceived barriers and benefits of exercise in methadone maintained persons. (United States)

    Caviness, Celeste M; Bird, Jessica L; Anderson, Bradley J; Abrantes, Ana M; Stein, Michael D


    Methadone-maintained persons are at increased risk for many physical and mental health disorders compared to the general population. Increased physical activity could offset these risks. We assessed physical activity level, and perceived benefits and barriers to exercise in a group of 305 methadone-maintained smokers. Mean participant age was 39.9 years, 50.2% were male, 79.7% were non-Hispanic White, and mean body mass index was 29.8. Nearly 45% endorsed fair or poor physical health. Although participants perceived many benefits of exercise and few barriers, only 38% of participants met weekly recommendations for physical activity, and nearly 25% reported no physical activity. Those who met recommended guidelines were significantly more likely to endorse relapse prevention as a benefit of exercise. Motivating MMT patients to increase physical activity could have important physical, mental health, and drug treatment benefits. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. An experience of intervention for maintaining the employment of disabled workers

    Directory of Open Access Journals (Sweden)

    Evandro Fornasier


    Full Text Available This article describes an active policy intervention in terms of integration into the labor of persons with disabilities, providing job maintaining support. Intervention was conducted using typical psychologist instruments using theoretical principles like multipersonal fields, community-based mental health and group analysis in psychosocial declination. This type of intervention although is not currently counted among the consolidated practices, could be considered as a "product" relevant to the psychologist's social mandate as long as it satisfies the needs and respond to the potential questions, expressed by social or / and by institutions. It also responds to indications provided by international organizations, about rights of persons with disabilities and categories at a social risk.Keywords: Disability and work; Job maintaining; Community-based mental health; Groups and work; Variable settings

  16. Analysis of Critical Factors and Difficulties in Maintaining Historical Building - A Current Implementation

    Directory of Open Access Journals (Sweden)

    Baharuddin M.N.


    Full Text Available Historic buildingis one of the highly valuable assets to the country especially in a way to shows its history for the next generation instead to make a profit through the excellent promotion in tourism purpose.The Malaysian Government has allocated a huge of financial support in order to conserve and preserve the historic building. However, the majority of the historic building is still in ‘poor’ condition without any improvement regarding to the pro-active approach.This paper presents part of this research which investigates the key components consists of issues and difficulties in term of critical factors. The findings reveal that there are several difficulties in maintaining a historic building. The identification of key components will facilitate the stakeholders to focus on the variable and resources to make the success in maintaining and managing the historic building.

  17. Zeste maintains repression of Ubx transgenes: Support for a new model of polycomb repression

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Man-Wook; Laney, Jeffrey D.; Jeon, Sang-Hack; Ali, Janann; Biggin, Mark D.


    During late embryogenesis, the expression domains of homeotic genes are maintained by two groups of ubiquitously expressed regulators: the Polycomb repressors and the Trithorax activators. It is not known how the activities of the two maintenance systems are initially targeted to the correct genes. Zeste and GAGA are sequence specific DNA binding proteins previously shown to be Trithorax group activators of the homeotic gene Ultrabithorax (Ubx). Here we demonstrate that Zeste and GAGA DNA binding sites at the proximal promoter are also required to maintain, but not to initiate, repression of Ubx. Further, the repression mediated by Zeste DNA binding site is abolished in zeste null embryos. These data imply that Zeste and probably GAGA mediate Polycomb repression. We present a model in which the dual transcriptional activities of Zeste and GAGA are an essential component of the mechanism that chooses which maintenance system is to be targeted to a given promoter.

  18. Vacuum infiltration of putrescine enhances bioactive compounds and maintains quality of blood orange during cold storage. (United States)

    Habibi, Fariborz; Ramezanian, Asghar


    The effects of putrescine (Put) treatment on anthocyanin concentrations and other bioactive compounds of two blood orange ('Moro' and 'Tarocco') cultivars during cold storage have been investigated. Put at 0, 1 and 2mM were applied to fruit by vacuum infiltration at 26.665kPa for 8min and then stored at 5°C, and 90% RH for 60days, plus a simulated shelf life of 2days at 20°C. Put treatment maintained higher fruit firmness and reduced weight loss during storage. Anthocyanin, total phenolic content (TPC), ascorbic acid content, and antioxidant activity were also higher in treated fruit than the control during storage. pH and titratable acidity (TA) were highest in treated fruit, while soluble solids concentration (SSC) and SSC/TA ratios were highest in untreated fruit. Overall, the quality of blood oranges maintained by Put treatment during cold storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Hale and Hearty Policies: How Psychological Science Can Create and Maintain Healthy Habits. (United States)

    Rothman, Alexander J; Gollwitzer, Peter M; Grant, Adam M; Neal, David T; Sheeran, Paschal; Wood, Wendy


    Strategies are needed to ensure that the U.S. Government meets its goals for improving the health of the nation (e.g., Healthy People 2020). To date, progress toward these goals has been undermined by a set of discernible challenges: People lack sufficient motivation, they frequently fail to translate healthy intentions into action, their efforts are undermined by the persistence of prior unhealthy habits, and they have considerable difficulty maintaining new healthy patterns of behavior. Guided by advances in psychological science, we provide innovative, evidence-based policies that address each of these challenges and, if implemented, will enhance people's ability to create and maintain healthy behavioral practices. © The Author(s) 2015.

  20. Wnt signaling-mediated redox regulation maintains the germ line stem cell differentiation niche. (United States)

    Wang, Su; Gao, Yuan; Song, Xiaoqing; Ma, Xing; Zhu, Xiujuan; Mao, Ying; Yang, Zhihao; Ni, Jianquan; Li, Hua; Malanowski, Kathryn E; Anoja, Perera; Park, Jungeun; Haug, Jeff; Xie, Ting


    Adult stem cells continuously undergo self-renewal and generate differentiated cells. In the Drosophila ovary, two separate niches control germ line stem cell (GSC) self-renewal and differentiation processes. Compared to the self-renewing niche, relatively little is known about the maintenance and function of the differentiation niche. In this study, we show that the cellular redox state regulated by Wnt signaling is critical for the maintenance and function of the differentiation niche to promote GSC progeny differentiation. Defective Wnt signaling causes the loss of the differentiation niche and the upregulated BMP signaling in differentiated GSC progeny, thereby disrupting germ cell differentiation. Mechanistically, Wnt signaling controls the expression of multiple glutathione-S-transferase family genes and the cellular redox state. Finally, Wnt2 and Wnt4 function redundantly to maintain active Wnt signaling in the differentiation niche. Therefore, this study has revealed a novel strategy for Wnt signaling in regulating the cellular redox state and maintaining the differentiation niche.

  1. Ergothioneine Maintains Redox and Bioenergetic Homeostasis Essential for Drug Susceptibility and Virulence of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Vikram Saini


    Full Text Available The mechanisms by which Mycobacterium tuberculosis (Mtb maintains metabolic equilibrium to survive during infection and upon exposure to antimycobacterial drugs are poorly characterized. Ergothioneine (EGT and mycothiol (MSH are the major redox buffers present in Mtb, but the contribution of EGT to Mtb redox homeostasis and virulence remains unknown. We report that Mtb WhiB3, a 4Fe-4S redox sensor protein, regulates EGT production and maintains bioenergetic homeostasis. We show that central carbon metabolism and lipid precursors regulate EGT production and that EGT modulates drug sensitivity. Notably, EGT and MSH are both essential for redox and bioenergetic homeostasis. Transcriptomic analyses of EGT and MSH mutants indicate overlapping but distinct functions of EGT and MSH. Last, we show that EGT is critical for Mtb survival in both macrophages and mice. This study has uncovered a dynamic balance between Mtb redox and bioenergetic homeostasis, which critically influences Mtb drug susceptibility and pathogenicity.

  2. Ergothioneine maintains redox and bioenergetic homeostasis essential for drug susceptibility and virulence of Mycobacterium tuberculosis (United States)

    Saini, Vikram; Cumming, Bridgette M.; Guidry, Loni; Lamprecht, Dirk; Adamson, John H.; Reddy, Vineel P.; Chinta, Krishna C.; Mazorodzo, James; Glasgow, Joel N.; Richard-Greenblatt, Melissa; Gomez-Velasco, Anaximandro; Bach, Horacio; Av-Gay, Yossef; Eoh, Hyungjin; Rhee, Kyu; Steyn, Adrie J.C.


    SUMMARY The mechanisms by which Mycobacterium tuberculosis (Mtb) maintains metabolic equilibrium to survive during infection and upon exposure to antimycobacterial drugs are poorly characterized. Ergothioneine (EGT) and mycothiol (MSH) are the major redox buffers present in Mtb, but the contribution of EGT to Mtb redox homeostasis and virulence remains unknown. We report that Mtb WhiB3, a 4Fe-4S redox sensor protein, regulates EGT production and maintains bioenergetic homeostasis. We show that central carbon metabolism and lipid precursors regulate EGT production and that EGT modulates drug sensitivity. Notably, EGT and MSH are both essential for redox and bioenergetic homeostasis. Transcriptomic analyses of EGT and MSH mutants indicate overlapping, but distinct functions of EGT and MSH. Lastly, we show that EGT is critical for Mtb survival in both macrophages and mice. This study has uncovered a dynamic balance between Mtb redox and bioenergetic homeostasis, which critically influences Mtb drug susceptibility and pathogenicity. PMID:26774486

  3. Atraumatic extraction and immediate implant installation: The importance of maintaining the contour gingival tissues (United States)

    Tavarez, Rudys Rodolfo De Jesus; dos Reis, Washigton Luís Machado; Rocha, Adrycila Teixeira; Firoozmand, Leily Macedo; Bandéca, Matheus Coêlho; Tonetto, Mateus Rodrigues; Malheiros, Adriana Santos


    There is an accelerated resorption in the first six months after the extraction of the dental element, both horizontally and vertically. These clinical changes normally undertake the aesthetic result of prosthetic rehabilitation, and implant installation after the extraction can be a resource to decrease resorption. The clinical case described in this paper demonstrates a sequence of clinical atraumatic extraction, and then the Immediate installation provisionalization. It is concluded that when carefully indicated and planned, this technique can provide an immediate result promising with maintaining the tooth gingival contour. How to cite this article: Tavarez RR, Machado dos Reis WL, Rocha AT, Firoozmand LM, Bandéca MC, Tonetto MR, Malheiros AS. Atraumatic extraction and immediate implant installation: The importance of maintaining the contour gingival tissues. J Int Oral Health 2013; 5(6):113-8 . PMID:24453455

  4. "Maintaining connections but wanting more": the continuity of familial relationships among assisted-living residents. (United States)

    Tompkins, Catherine J; Ihara, Emily S; Cusick, Alison; Park, Nan Sook


    Social support is a key component of well-being for older adults, particularly for those who have moved from independent living to assisted living involving a transformation of roles, relationships, and responsibilities. Twenty-nine assisted-living facility residents were interviewed to understand the perceived continuity of relationships with family and friends. An inductive approach to thematic analysis revealed 1 main theme and 3 subthemes. The main theme that emerged was: maintaining connections but wanting more. Residents appreciated maintaining connections with family and friends, but often expressed feelings of discontentment with the continuity of former relationships. The subthemes included: appreciating family and friends, waiting for more, and losing control. Implications for research and practice are discussed.

  5. Glucose is necessary to maintain neurotransmitter homeostasis during synaptic activity in cultured glutamatergic neurons

    DEFF Research Database (Denmark)

    Bak, Lasse K; Schousboe, Arne; Sonnewald, Ursula


    Glucose is the primary energy substrate for the adult mammalian brain. However, lactate produced within the brain might be able to serve this purpose in neurons. In the present study, the relative significance of glucose and lactate as substrates to maintain neurotransmitter homeostasis...... was unaffected by the choice of substrate. In conclusion, the present study shows that glucose is a necessary substrate to maintain neurotransmitter homeostasis during synaptic activity and that synaptic activity does not induce an upregulation of lactate metabolism in glutamatergic neurons....... was investigated. Cultured cerebellar (primarily glutamatergic) neurons were superfused in medium containing [U-13C]glucose (2.5 mmol/L) and lactate (1 or 5 mmol/L) or glucose (2.5 mmol/L) and [U-13C]lactate (1 mmol/L), and exposed to pulses of N-methyl-D-aspartate (300 micromol/L), leading to synaptic activity...

  6. Effect of wobble board training on movement strategies to maintain equilibrium on unstable surfaces

    DEFF Research Database (Denmark)

    Silva, Priscila de Brito; Mrachacz-Kersting, Natalie; Oliveira, Anderson Souza


    Standing on unstable surfaces requires more complex motor control mechanisms to sustain balance when compared to firm surfaces. Surface instability enhances the demand to maintain equilibrium and is often used to challenge balance, but little is known about how balance training affects movement...... strategies to control posture while standing on unstable surfaces. This study aimed at assessing the effects of isolated wobble board (WB) training on movement strategies to maintain balance during single-leg standing on a WB. Twenty healthy men were randomly assigned to either a control or a training group....... The training group took part in four weeks of WB training and both groups were tested pre and post the intervention. Electromyography from the supporting lower limb muscles, full-body kinematics and ground reaction forces were recorded during firm surface (FS) and WB single-leg standing. WB training did...

  7. Physical objects as vehicles of cultural transmission: maintaining harmony and uniqueness through colored geometric patterns. (United States)

    Ishii, Keiko; Miyamoto, Yuri; Rule, Nicholas O; Toriyama, Rie


    We examined how cultural values of harmony and uniqueness are represented and maintained through physical media (i.e., colorings of geometric patterns) and how individuals play an active role in selecting and maintaining such cultural values. We found that colorings produced by European American adults and children were judged as more unique, whereas colorings produced by Japanese adults and children were judged as more harmonious, reflecting cultural differences in values. Harmony undergirded Japanese participants' preferences for colorings, whereas uniqueness undergirded European American participants' preferences for colorings. These cultural differences led participants to prefer own-culture colorings over other-culture colorings. Moreover, bicultural participants' preferences acculturated according to their identification with their host culture. Furthermore, child rearers in Japan and Canada gave feedback about the children's colorings that were consistent with their culture's values. These findings suggest that simple geometric patterns can embody cultural values that are socialized and reinforced from an early age.

  8. Academic portfolio in the digital era: organizing and maintaining a portfolio using reference managers. (United States)

    Bhargava, Puneet; Patel, Vatsal B; Iyer, Ramesh S; Moshiri, Mariam; Robinson, Tracy J; Lall, Chandana; Heller, Matthew T


    The academic portfolio has become an integral part of the promotions process. Creating and maintaining an academic portfolio in paper-based or web-based formats can be a cumbersome and time-consuming task. In this article, we describe an alternative way to efficiently organize an academic portfolio using a reference manager software, and discuss some of the afforded advantages. The reference manager software Papers (Mekentosj, Amsterdam, The Netherlands) was used to create an academic portfolio. The article outlines the key steps in creating and maintaining a digital academic portfolio. Using reference manager software (Papers), we created an academic portfolio that allows the user to digitally organize clinical, teaching, and research accomplishments in an indexed library enabling efficient updating, rapid retrieval, and easy sharing. To our knowledge, this is the first digital portfolio of its kind.

  9. BPTF Maintains Chromatin Accessibility and the Self-Renewal Capacity of Mammary Gland Stem Cells

    Directory of Open Access Journals (Sweden)

    Wesley D. Frey


    Full Text Available Chromatin remodeling is a key requirement for transcriptional control of cellular differentiation. However, the factors that alter chromatin architecture in mammary stem cells (MaSCs are poorly understood. Here, we show that BPTF, the largest subunit of the NURF chromatin remodeling complex, is essential for MaSC self-renewal and differentiation of mammary epithelial cells (MECs. BPTF depletion arrests cells at a previously undefined stage of epithelial differentiation that is associated with an incapacity to achieve the luminal cell fate. Moreover, genome-wide analysis of DNA accessibility following genetic or chemical inhibition, suggests a role for BPTF in maintaining the open chromatin landscape at enhancers regions in MECs. Collectively, our study implicates BPTF in maintaining the unique epigenetic state of MaSCs.

  10. Maintaining confidentiality in prospective studies: anonymous repeated measurements via email (ARME) procedure. (United States)

    Carli, Vladimir; Hadlaczky, Gergö; Wasserman, Camilla; Stingelin-Giles, Nicola; Reiter-Theil, Stella; Wasserman, Danuta


    Respecting and protecting the confidentiality of data and the privacy of individuals regarding the information that they have given as participants in a research project is a cornerstone of complying with accepted research standards. However, in longitudinal studies, establishing and maintaining privacy is often challenging because of the necessity of repeated contact with participants. A novel internet-based solution is introduced here, which maintains privacy while at the same time ensures linkage of data to individual participants in a repeated measures design. With the use of the anonymous repeated measurements via email (ARME) procedure, two separate one-way communication systems are established through ad hoc email accounts and a secure study website. Strengths and limitations of the approach are discussed.

  11. Maintainability Test Report for the AN/TRN-41 TACAN Navigational Set (United States)


    ILL Q A ENGINEERING ^^^^^iiju^^^^ Figuro 3, AmniRCfREWES^ITATIVE ^2L -18- äaaijt.^^i...;.: i^psfi^’^ff’raswys^wwsf wmw ^mmm^^f^^m^mm^mmm^B^f...Certification. Each Maintainability Demonstration Analysis sheet has been signed by Montek Engineering and Quality Assurance representatives and by...MAINTENANCE STEPS PERFORMED f**uo~^A REMARKS! ENGINEERING ^v- TIME RECORD <-**- &’ IC-. Troubleshoottime Repair Time Alignment

  12. Process Of Acceptance And Nurturing By Parents To Maintain Caring Affection To The Children With Hydrocephalus


    Ageng Wirdhana, Sri; Naryoso, S.Sos, M.Si, Agus


    Based on data from The Ministry of Health Republic of Indonesia, there were 20 newborn babies suffered hydrocephalus from every 10.000 birth in Indonesia, Margaretha (Clinical Pshychology and Mental Health, 2014: Vol. 03, No.2). Hydrocephalus is a condition when the main characteristic is the excessive liquid accumulation in brain. This research aim to explain the process of acceptance and nurturing by parents to maintain caring affection to hydrocephalus children. This research used descript...

  13. Maintaining the chain of custody--evidence handling in forensic cases. (United States)

    Evans, Mary Margaret; Stagner, Pamela A; Rooms, Rusty


    IN VIOLENCE AND ABUSE CASES, perioperative nurses are responsible for protecting victims' rights and ensuring that potential evidence of a crime is not compromised. FORMAL EDUCATION for nurses now is available in the relatively new field of clinical forensic nursing. PERIOPERATIVE NURSES should ensure that they receive proper education in identifying, collecting and securing evidence and maintaining the chain of custody, whether through a formal education process or by reviewing protocols at their facilities.

  14. Distinct Neural Substrates for Maintaining Locations and Spatial Relations in Working Memory

    Directory of Open Access Journals (Sweden)

    Kara J Blacker


    Full Text Available Previous work has demonstrated a distinction between maintenance of two types of spatial information in working memory (WM: spatial locations and spatial relations. While a body of work has investigated the neural mechanisms of sensory-based information like spatial locations, little is known about how spatial relations are maintained in WM. In two experiments, we used fMRI to investigate the involvement of early visual cortex in the maintenance of spatial relations in WM. In both experiments, we found less quadrant-specific BOLD activity in visual cortex when a single spatial relation, compared to a single spatial location, was held in WM. Also across both experiments, we found a consistent set of brain regions that were differentially activated during maintenance of locations versus relations. Maintaining a location, compared to a relation, was associated with greater activity in typical spatial WM regions like posterior parietal cortex and prefrontal regions. Whereas maintaining a relation, compared to a location, was associated with greater activity in the parahippocampal gyrus and precuneus/retrosplenial cortex. Further, in Experiment 2 we manipulated WM load and included trials where participants had to maintain three spatial locations or relations. Under this high load condition, the regions sensitive to locations versus relations were somewhat different than under low load. We also identified regions that were sensitive to load specifically for location or relation maintenance, as well as overlapping regions sensitive to load more generally. These results suggest that the neural substrates underlying WM maintenance of spatial locations and relations are distinct from one another and that the neural representations of these distinct types of spatial information change with load.

  15. Effects in “Introduction to Psychology” ClassⅡ: Could Students Maintain Metacognitive Skills?


    荒木, 史代; Araki, Fumiyo


    This study examined the effect of implementation to enhance and maintain metacognitive skills for students who had taken “Introduction to Psychology” class for freshmen. In the follow-up study had about one year after the class had finished, the results of the implementing group demonstrated significantly higher level of stress management self-efficacy scales than the control group. Also, the metacognitive skills scales of the implementing group indicated marginally significant results higher...

  16. In Sickness and in Health: Maintaining Intimacy After Breast Cancer Recurrence


    Andersen, Barbara L.


    Sexual well-being after breast cancer recurrence has received little clinical attention. In discussing the sexual difficulties after recurrence we draw upon our longitudinal studies of newly diagnosed patients. It is noted that sexuality declines after a patient’s initial diagnosis and treatment, with further decline after recurrence. However, data suggest that couples strive to maintain intimacy as the health of the patient falters, providing further evidence of the resilience of patients co...

  17. Method and apparatus for maintaining equilibrium in a helical axis stellarator (United States)

    Reiman, A.; Boozer, A.


    Apparatus for maintaining three-dimensional MHD equilibrium in a plasma contained in a helical axis stellarator includes a resonant coil system, having a configuration such that current therethrough generates a magnetic field cancelling the resonant magnetic field produced by currents driven by the plasma pressure on any given flux surface resonating with the rotational transform of another flux surface in the plasma. Current through the resonant coil system is adjusted as a function of plasma beta.

  18. Insurrection Act Restored: States Likely to Maintain Authority over National Guard in Domestic Emergencies (United States)


    interracial violence. In April of 1871, South Carolina Governor Robert Kingston Scott requested assistance from the President to maintain order in the face...efforts in New Orleans could have been better coordinated, one major blunder is not sufficient reason to alter a centuries-old relationship in which...control of National Guard forces and thereby inadvertently usurp a governor. If the President has an antagonistic relationship with a governor, there may

  19. Effects of presession attention on the frequency of attention-maintained behavior.


    O'Reilly, M F


    The effect of prior attention was systematically manipulated to study its influence on rates of yelling and head hitting, both maintained by positive reinforcement in the form of attention. Higher levels of head hitting occurred in analogue attention conditions when the person was deprived of attention (no social interactions for 1 hr) prior to the analysis in comparison to when the person received high levels of attention (attention delivered on a fixed-time 30-s schedule for 1 hr) prior to ...

  20. Significant head cooling can be achieved while maintaining normothermia in the newborn piglet. (United States)

    Tooley, J R; Eagle, R C; Satas, S; Thoresen, M


    Hypothermia has been shown to be neuroprotective in animal models of hypoxia-ischaemia. It is currently being evaluated as a potentially therapeutic option in the management of neonatal hypoxic-ischaemic encephalopathy. However, significant hypothermia has adverse systemic effects. It has also recently been found that the stress of being cold can abolish the neuroprotective effects of hypothermia. It is hypothesised that selective head cooling (SHC) while maintaining normal core temperature would enable local hypothermic neuroprotection while limiting the stress and side effects of hypothermia. To determine whether it is possible to induce moderate cerebral hypothermia in the deep brain of the piglet while maintaining the body at normothermia (39 degrees C). Six piglets (piglet was head cooled for seven hours using a cap circulated with cold water (median 8.9 degrees C (interquartile range 7.5-14)) wrapped around the head. Radiant overhead heating was used to warm the body during cooling. During SHC it was possible to cool the brain while maintaining a normal core temperature. The mean (SD) T(deep brain) during the seven hour cooling period was 31.1 (4.9) degrees C while T(rectal) remained stable at 38.8 (0.4) degrees C. The mean T(rectal)-T(deep brain) difference throughout the cooling period was 9.8 (6.1) degrees C. The mean T(skin) required was 40.8 (1.1) degrees C. There was no evidence of skin damage secondary to these skin temperatures. During cooling only one piglet shivered. It is possible to maintain systemic normothermia in piglets while significantly cooling the deeper structures of the brain. This method of cooling may further limit the side effects associated with systemic hypothermia and be feasible for premature infants.

  1. Characterization of Polarization-Maintaining Fiber Using High-Sensitivity Optical-Frequency-Domain Reflectometry (United States)

    Froggatt, Mark E.; Gifford, Dawn K.; Kreger, Steven; Wolfe, Matthew; Soller, Brian J.


    Optical-frequency-domain reflectometry is used to measure the group-index difference and the refractive-index difference (i.e., beat length) between the fast and slow modes in polarization-maintaining optical fiber. The Rayleigh scatter normally present in the fiber is measured in reflection. This measurement, in turn, enables a distributed measurement of the fiber's birefringence that is rapid and completely nondestructive.

  2. The strenuous task of maintaining and making friends : Tensions between play and friendship in MMOs


    Eklund, Lina; Ask, Kristine


    This empirically driven study concerns the creation and maintenance of friendships in online gaming. Social interaction and community building are integral to online game-play, yet maintaining and making friends within a gaming context is not without its conflicts. Through analyses of interview data (n=52) combined from two research projects concerning MMO-gaming this study presents three ideal type portraits of gamers. The portraits illustrate different struggles of balancing friendships, a ...

  3. The Real Transformation: Building and Maintaining Long-Term Competitive Advantage (United States)


    TERM COMPETITIVE ADVANTAGE LTC EDWARD C. CARDON, USA A TRANFORMATION PAPER FOR THE CHAIRMAN OF THE JOINT CHIEFS OF STAFF SEMINAR...SUBTITLE The Real Transformation: Building and Maintaining Long-Term Competitive Advantage 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...long-term military competitive advantage in comparison to the rest of the world.4 This approach suggests a model that places competition as the

  4. Reduced reactivation from dormancy but maintained lineage choice of human mesenchymal stem cells with donor age.

    Directory of Open Access Journals (Sweden)

    Verena Dexheimer

    Full Text Available UNLABELLED: Mesenchymal stem cells (MSC are promising for cell-based regeneration therapies but up to date it is still controversial whether their function is maintained throughout ageing. Aim of this study was to address whether frequency, activation in vitro, replicative function, and in vitro lineage choice of MSC is maintained throughout ageing to answer the question whether MSC-based regeneration strategies should be restricted to younger individuals. MSC from bone marrow aspirates of 28 donors (5-80 years were characterized regarding colony-forming unit-fibroblast (CFU-F numbers, single cell cloning efficiency (SSCE, osteogenic, adipogenic and chondrogenic differentiation capacity in vitro. Alkaline phosphatase (ALP activity, mineralization, Oil Red O content, proteoglycan- and collagen type II deposition were quantified. While CFU-F frequency was maintained, SSCE and early proliferation rate decreased significantly with advanced donor age. MSC with higher proliferation rate before start of induction showed stronger osteogenic, adipogenic and chondrogenic differentiation. MSC with high osteogenic capacity underwent better chondrogenesis and showed a trend to better adipogenesis. Lineage choice was, however, unaltered with age. CONCLUSION: Ageing influenced activation from dormancy and replicative function of MSC in a way that it may be more demanding to mobilize MSC to fast cell growth at advanced age. Since fast proliferation came along with high multilineage capacity, the proliferation status of expanded MSC rather than donor age may provide an argument to restrict MSC-based therapies to certain individuals.

  5. Apparatus and method for maintaining low temperatures about an object at a remote location. [Patent application (United States)

    Steyert, W.A. Jr.; Overton, W.C. Jr.


    The disclosure is directed to an apparatus and method for maintaining a body at cryogenic temperatures at a remote location such as down a borehole for an extended period of time. A housing contains a body comprising a material having a high specific heat at cryogenic temperatures such as between about 2 and 15 K. The body contains an orifice for containing an instrument or instruments operable at superconducting temperatures. The apparatus is precooled at the surface and lowered into a borehole to a desired depth, such as 2 to 3 miles. The instruments are operated, and the apparatus withdrawn, the material of the body maintaining the very low temperatures at which the instrument(s) operate for a sufficient period of time at the remote or downhole location. The material may comprise a rare earth compound, such as Gd/sub 2/O/sub 3/, Gd/sub 2/Se/sub 3/, Gd/sub 2/O/sub 2/S or GdAlO/sub 3/. Monoclinic and C-phase gadolinium oxides work well. A low temperature is maintainable at a remote location for several hours.

  6. Analysis of Possibility of Yeast Production Increase at Maintained Carbon Dioxide Emission Level

    Directory of Open Access Journals (Sweden)

    Włodarczyk Barbara


    Full Text Available Main parameters polluting of technological wastewater (dregs from decantation and thicken of the wort from yeast industry are: nitrogen, potassium and COD. Such wastewater are utilized mostly on agricultural fields. Unfortunately, these fields can only accept a limited amount of wastes. The basic parameter limiting there the amount of wastewater is nitrogen. When capacity of the production is large sewages are often pretreated at an evaporator station. However, due to the fairly high running costs of the evaporator station currently such a solution is applied only to a small amount of wastes (just to meet legal requirements. Replacement of the earth gas with a biomass being supplied to the evaporator station from the agricultural fields will both allow to maintain the carbon dioxide emission level and enable the production growth. Moreover, the biomass growing on the agricultural fields being fertilized with the wastewater coming from the yeast production allows consequently to utilize the greater volume of wastewater. Theoretically, the possible increase in the yeasts production, with maintaining the carbon dioxide emission level, can reach even 70%. Therefore, the solution presented in this paper combines both intensification of the yeasts production and maintaining the carbon dioxide emission level.

  7. Analysis of Possibility of Yeast Production Increase at Maintained Carbon Dioxide Emission Level (United States)

    Włodarczyk, Barbara; Włodarczyk, Paweł P.


    Main parameters polluting of technological wastewater (dregs from decantation and thicken of the wort) from yeast industry are: nitrogen, potassium and COD. Such wastewater are utilized mostly on agricultural fields. Unfortunately, these fields can only accept a limited amount of wastes. The basic parameter limiting there the amount of wastewater is nitrogen. When capacity of the production is large sewages are often pretreated at an evaporator station. However, due to the fairly high running costs of the evaporator station currently such a solution is applied only to a small amount of wastes (just to meet legal requirements). Replacement of the earth gas with a biomass being supplied to the evaporator station from the agricultural fields will both allow to maintain the carbon dioxide emission level and enable the production growth. Moreover, the biomass growing on the agricultural fields being fertilized with the wastewater coming from the yeast production allows consequently to utilize the greater volume of wastewater. Theoretically, the possible increase in the yeasts production, with maintaining the carbon dioxide emission level, can reach even 70%. Therefore, the solution presented in this paper combines both intensification of the yeasts production and maintaining the carbon dioxide emission level.

  8. A mechanism that maintains alternative life histories in a loggerhead sea turtle population. (United States)

    Hatase, Hideo; Omuta, Kazuyoshi; Tsukamoto, Katsumi


    Intrapopulation variation in habitat use is commonly seen among mobile animals, yet the mechanisms maintaining it have rarely been researched among untrackable species. To investigate how alternative life histories are maintained in a population of the loggerhead sea turtle (Caretta caretta), cumulative reproductive output was evaluated and compared between small planktivores inhabiting oceanic areas (with water depths > 200 m) and large benthivores inhabiting neritic areas (depths life history parameters (clutch size, clutch frequency, breeding frequency, and remigration intervals), with the exception of emergence success. We did not find evidence of life history trade-offs, nor age-related changes in fecundity. Over the 26-year study period, we calculated a 2.4-fold greater reproductive output for neritic foragers than for oceanic ones, accounting for breeding and clutch frequency. Temporal consistencies in stable isotope ratios and remigration intervals within females suggested that female Japanese loggerheads show fidelity to respective foraging habitats throughout the adult stage. The large difference in productivity between the two groups was unlikely to be offset by the difference in survival during the period from aboveground emergence to first reproduction, suggesting that oceanic foragers have a lower level of fitness than neritic ones. Together with an absence of genetic structure between foraging groups, we infer that alternative life histories in a loggerhead turtle population are maintained by a conditional strategy.

  9. Biodegradation of nickel and chromium from space maintainers: An in vitro study

    Directory of Open Access Journals (Sweden)

    Bhaskar V


    Full Text Available Band materials are often used in the practice of pediatric dentistry. Nickel and Chromium are the main ingredients of these materials. The potential health hazards of nickel and chromium and their compounds have been the focus of attention for more than 100 years. It has established that these metals could cause hypersensitivity. The study was undertaken to analyze in vitro biodegradation of space maintainers made out of stainless steel band materials from manufacturers Dentaurum and Unitek. The leaching effect simulating the use of one, two, three, and four space maintainers in clinical practice was studied by keeping the respective number of space maintainers in the artificial saliva incubating at 37°C and analyzing for nickel and chromium release after 1,7,14,21 and 28 days using atomic absorption spectrophotometer. Results showed that there was measurable release of both nickel and chromium which reached maximum level at the end of 7 days which was statistically significant (P < 0.05 and was very much below the dietary average intake even for four bands used and was not capable of causing any toxicity.

  10. Heterogeneity for IGF-II production maintained by public goods dynamics in neuroendocrine pancreatic cancer. (United States)

    Archetti, Marco; Ferraro, Daniela A; Christofori, Gerhard


    The extensive intratumor heterogeneity revealed by sequencing cancer genomes is an essential determinant of tumor progression, diagnosis, and treatment. What maintains heterogeneity remains an open question because competition within a tumor leads to a strong selection for the fittest subclone. Cancer cells also cooperate by sharing molecules with paracrine effects, such as growth factors, and heterogeneity can be maintained if subclones depend on each other for survival. Without strict interdependence between subclones, however, nonproducer cells can free-ride on the growth factors produced by neighboring producer cells, a collective action problem known in game theory as the "tragedy of the commons," which has been observed in microbial cell populations. Here, we report that similar dynamics occur in cancer cell populations. Neuroendocrine pancreatic cancer (insulinoma) cells that do not produce insulin-like growth factor II (IGF-II) grow slowly in pure cultures but have a proliferation advantage in mixed cultures, where they can use the IGF-II provided by producer cells. We show that, as predicted by evolutionary game theory, producer cells do not go extinct because IGF-II acts as a nonlinear public good, creating negative frequency-dependent selection that leads to a stable coexistence of the two cell types. Intratumor cell heterogeneity can therefore be maintained even without strict interdependence between cell subclones. Reducing the amount of growth factors available within a tumor may lead to a reduction in growth followed by a new equilibrium, which may explain relapse in therapies that target growth factors.

  11. Self-guided Change: The most common form of long-term, maintained health behavior change. (United States)

    Bishop, F Michler


    Millions of people change risky, health-related behaviors and maintain those changes. However, they often take years to change, and their unhealthy behaviors may harm themselves and others and constitute a significant cost to society. A review-similar in nature to a scoping review-was done of the literature related to long-term health behavior change in six areas: alcohol, cocaine and heroin misuse, gambling, smoking, and overeating. Based on the limited research available, reasons for change and strategies for changing and for maintaining change were also reviewed. Fifty years of research clearly indicate that as people age, in the case of alcohol, heroin and cocaine misuse, smoking, and gambling, 80-90 percent moderate or stop their unhealthy behaviors. The one exception is overeating; only 20 percent maintain their weight loss. Most of these changes, when they occur, appear to be the result of self-guided change. More ways to accelerate self-guided, health-related behavior change need to be developed and disseminated.

  12. Study on maintaining formations during satellite formation flying based on SDRE and LQR

    Directory of Open Access Journals (Sweden)

    Ke Zhang


    Full Text Available Due to the influence of various perturbations of space, satellites flying in formation cannot maintain specific configurations for long durations [1, 2]. In order to ensure that formation configurations are able to meet the requirements of space missions, it is important to maintain control of formation configurations. This is an urgent problem to be solved. The traditional control method for controlling formations is based on the average orbit element, and uses the assumption that the average orbit element deviation and the instantaneous orbit element deviation are approximately equal. However, the continuous control system is more difficult to achieve in engineering practice. Using a LQR (linear quadratic regulator optimal control algorithm and SDRE (state-dependent Riccati equation optimal control algorithm to maintain the formation flying [3, 4]. Through simulation, it was found that when using the SDRE controller in the system transition process time is shorter than when the LQR controller is used, and fuel consumption is less for the SDRE controller than for the LQR controller.

  13. Na(+) /H(+) exchanger 1 (NHE1) function is necessary for maintaining mammary tissue architecture. (United States)

    Jenkins, Edmund C; Debnath, Shawon; Varriano, Sophia; Gundry, Stephen; Fata, Jimmie E


    The mammary gland is an ideal model to study the link between form and function in normal tissue. Perhaps as interesting as the cues necessary to generate this structure are the signals required to maintain its branched architecture over the lifetime of the organism, since likely these pathways are de-regulated in malignancies. Previously, we have shown that the Na(+) /H(+) exchanger 1 (NHE1), a critical regulator of intracellular pH, was necessary for mammary branching morphogenesis. Here we provide strong evidence that NHE1 function is also necessary for maintaining mammary branched architecture. Inhibition of NHE1 with 5-N-Methy-N-isobutyl amiloride (MIA) on branched structures resulted in a rapid (within 24 hr) and reversible loss of branched architecture that was not accompanied by any overt changes in cell proliferation or cell death. NHE1 inhibition led to a significant acidification of intracellular pH in the branched end buds that preceded a number of events, including altered tissue polarity of myoepithelial cells, loss of NHE1 basal polarity, F-actin rearrangements, and decreased E-cadherin expression. Our results implicate NHE1 function and intracellular pH homeostasis as key factors that maintain mammary tissue architecture, thus, indirectly allowing for mammary function as a milk-providing (form) and -producing (function) gland. Copyright © 2013 Wiley Periodicals, Inc.

  14. Decision making for mothers with cancer: maintaining the mother-child bond. (United States)

    Campbell-Enns, Heather J; Woodgate, Roberta L


    The objective of this study was to explore the process of decision-making in mothers with cancer when they are mothering young children. The purpose of this article is to describe the core category that emerged from the study as well as the conditions precipitating decision making and the consequences of decision making for mothers with cancer. A qualitative methodology based on the tenets of constructivist grounded theory was used to conduct ten interviews with eight mothers with cancer. Data analysis revealed the core category, the conditions of the decision situation as well as the consequences of decision making. The core category was the meaning that mothers made of decisions, specifically that each decision was made to maintain the mother-child bond. The conditions of the mothers' lives influenced the meaning mothers assigned to decisions. The consequences of decision making were displayed by these mothers through coping strategies to facilitate maintaining the mother-child bond in times of distress. The conditions of the mothers' lives created a context in which mothers made meaning of decisions. Mothers aimed to maintain their bonds with their children in the decision making process and used various coping strategies as a consequence to distress from decisional situations. The results have implications for future decision making research in cancer care. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. The barriers to smoking cessation in Swiss methadone and buprenorphine-maintained patients

    Directory of Open Access Journals (Sweden)

    Stohler Rudolf


    Full Text Available Abstract Background Smoking rates in methadone-maintained patients are almost three times higher than in the general population and remain elevated and stable. Due to the various negative health effects of smoking, nicotine dependence contributes to the high mortality in this patient group. The purpose of the current study was to investigate Swiss methadone and buprenorphine-maintained patients' willingness to stop smoking and to clarify further smoking cessation procedures. Methods Substance abuse history, nicotine dependence, and readiness to stop smoking were assessed in a sample of 103 opiate-dependent patients in the metropolitan area of Zurich, Switzerland. Patients were asked to document their smoking patterns and readiness to quit. Results Only a small number of patients were willing to quit smoking cigarettes (10.7% and, even though bupropione or nicotine replacement therapy was included in the fixed daily treatment care, only one patient received nicotine replacement therapy for smoking cessation. A diagnosis of depression in patients' clinical records was associated with readiness to stop smoking. No significant associations were found between readiness to quit smoking and age, methadone treatment characteristics, and presence of co-dependencies. Conclusion The current prescription level of best medicine for nicotine dependence in Swiss methadone and buprenorphine-maintained patients is far from adequate. Possible explanations and treatment-relevant implications are discussed.

  16. Experience of maintaining tooth brushing for children born with a cleft lip and/or palate. (United States)

    Lin, Yin-Ling; Davies, Karen; Callery, Peter


    Children with a Cleft Lip and/or Palate (CL/P) have been reported to have poorer oral health than those without the condition. The consequences for these children can be particularly problematic due to implications for future treatments. Tooth brushing is an important behaviour contributing to children's oral health, but is under researched in the CL/P population. The aim of the study is to explore the experience of maintaining tooth brushing among children in the United Kingdom (UK) with a CL/P and their parents. Semi-structured interviews were carried out with twenty-two parents and sixteen children with a CL/P (5-11 years), recruited at a cleft centre in the UK. Thematic analysis was used for data analysis. Three key themes were drawn from the qualitative data: first, parents of children with a CL/P generally had strong motivation to look after their children's teeth but children's motivation was inconsistent. Second, parents were primary enablers of children's tooth brushing behaviour, often employing approaches adapted to their child's characteristics to encourage tooth brushing. Third, a range of obstacles were encountered by parents and children in maintaining regular tooth brushing behaviours. They reported obstacles such as issues related to CL/P, 'forgetting' and childhood illness. The paper suggests that parents of children with a CL/P need support to enact their intention to maintain regular tooth brushing and prioritise tooth brushing within the context of demanding and dynamic family life.

  17. Smad4 is required to inhibit osteoclastogenesis and maintain bone mass (United States)

    Morita, Mayu; Yoshida, Shigeyuki; Iwasaki, Ryotaro; Yasui, Tetsuro; Sato, Yuiko; Kobayashi, Tami; Watanabe, Ryuichi; Oike, Takatsugu; Miyamoto, Kana; Takami, Masamichi; Ozato, Keiko; Deng, Chu-Xia; Aburatani, Hiroyuki; Tanaka, Sakae; Yoshimura, Akihiko; Toyama, Yoshiaki; Matsumoto, Morio; Nakamura, Masaya; Kawana, Hiromasa; Nakagawa, Taneaki; Miyamoto, Takeshi


    Bone homeostasis is maintained as a delicate balance between bone-resorption and bone-formation, which are coupled to maintain appropriate bone mass. A critical question is how bone-resorption is terminated to allow bone-formation to occur. Here, we show that TGFβs inhibit osteoclastogenesis and maintain bone-mass through Smad4 activity in osteoclasts. We found that latent-TGFβ1 was activated by osteoclasts to inhibit osteoclastogenesis. Osteoclast-specific Smad4 conditional knockout mice (Smad4-cKO) exhibited significantly reduced bone-mass and elevated osteoclast formation relative to controls. TGFβ1-activation induced expression of Irf8 and Bcl6, both of which encode factors inhibiting osteoclastogenesis, by blocking their negative regulator, Prdm1, in osteoclasts in a Smad4-dependent manner. Reduced bone-mass and accelerated osteoclastogenesis seen in Smad4-cKO were abrogated by Prdm1 deletion. Administration of latent-TGFβ1-Fc to wild-type mice antagonized LPS-induced bone destruction in a model of activated osteoclast-mediated bone destruction. Thus, latent-TGFβ1-Fc could serve as a promising new therapeutic agent in bone diseases marked by excessive resorption. PMID:27731422

  18. CrxOS maintains the self-renewal capacity of murine embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Ryota; Yamasaki, Tokiwa; Nagai, Yoko; Wu, Jinzhan [Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Kajiho, Hiroaki [Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Yokoi, Tadashi; Noda, Eiichiro [Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Department of Ophthalmology, National Center for Child Health and Development, Tokyo 157-8535 (Japan); Nishina, Sachiko [Department of Ophthalmology, National Center for Child Health and Development, Tokyo 157-8535 (Japan); Niwa, Hitoshi [Laboratory for Pluripotent Cell Studies, RIKEN Center for Developmental Biology, Hyogo 650-0047 (Japan); Azuma, Noriyuki [Department of Ophthalmology, National Center for Child Health and Development, Tokyo 157-8535 (Japan); Katada, Toshiaki [Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Nishina, Hiroshi, E-mail: [Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan)


    Embryonic stem (ES) cells maintain pluripotency by self-renewal. Several homeoproteins, including Oct3/4 and Nanog, are known to be key factors in maintaining the self-renewal capacity of ES cells. However, other genes required for the mechanisms underlying this process are still unclear. Here we report the identification by in silico analysis of a homeobox-containing gene, CrxOS, that is specifically expressed in murine ES cells and is essential for their self-renewal. ES cells mainly express the short isoform of endogenous CrxOS. Using a polyoma-based episomal expression system, we demonstrate that overexpression of the CrxOS short isoform is sufficient for maintaining the undifferentiated morphology of ES cells and stimulating their proliferation. Finally, using RNA interference, we show that CrxOS is essential for the self-renewal of ES cells, and provisionally identify foxD3 as a downstream target gene of CrxOS. To our knowledge, ours is the first delineation of the physiological role of CrxOS in ES cells.

  19. Toxoplasma gondii antigens: recovery analysis of tachyzoites cultivated in Vero cell maintained in serum free medium. (United States)

    da Costa-Silva, Thaís Alves; da Silva Meira, Cristina; Frazzatti-Gallina, Neuza; Pereira-Chioccola, Vera Lucia


    Vero cells have been used successfully in Toxoplasma gondii maintenance. Medium supplementation for culture cells with fetal bovine serum is necessary for cellular growth. However, serum in these cultures presents disadvantages, such as the potential to induce hypersensitivity, variability of serum batches, possible presence of contaminants, and the high cost of good quality serum. Culture media formulated without any animal derived components, designed for serum-free growth of cell lines have been used successfully for different virus replication. The advantages of protozoan parasite growth in cell line cultures using serum-free medium remain poorly studied. Thus, this study was designed to determine whether T. gondii tachyzoites grown in Vero cell cultures in serum-free medium, after many passages, are able to maintain the same antigenic proprieties as those maintained in experimental mice. The standardization of Vero cell culture in serum-free medium for in vitro T. gondii tachyzoite production was performed establishing the optimal initial cell concentration for the confluent monolayer formation, which was 1×10(6) Vero cell culture as initial inoculum. The total confluent monolayer formatted after 96 h and the best amount of harvested tachyzoites was 2.1×10(7) using parasite inoculum of 1.5×10(6) after 7 days post-infection. The infectivity of tachyzoites released from Vero cells maintained in serum-free medium was evaluated using groups of Swiss mice infected with cell-culture tachyzoites. The parasite concentrations were similar to those for mice infected with tachyzoites collected from other infected mice. The data from both in vivo and in vitro experiments showed that in at least 30 culture cell passages, the parasites maintained the same infectivity as maintained in vivo. Another question was to know whether in the several continued passages, immunogenic progressive loss could occur. The nucleotide sequences studied were the same between the different

  20. Maintaining a cognitive map in darkness: the need to fuse boundary knowledge with path integration. (United States)

    Cheung, Allen; Ball, David; Milford, Michael; Wyeth, Gordon; Wiles, Janet


    Spatial navigation requires the processing of complex, disparate and often ambiguous sensory data. The neurocomputations underpinning this vital ability remain poorly understood. Controversy remains as to whether multimodal sensory information must be combined into a unified representation, consistent with Tolman's "cognitive map", or whether differential activation of independent navigation modules suffice to explain observed navigation behaviour. Here we demonstrate that key neural correlates of spatial navigation in darkness cannot be explained if the path integration system acted independently of boundary (landmark) information. In vivo recordings demonstrate that the rodent head direction (HD) system becomes unstable within three minutes without vision. In contrast, rodents maintain stable place fields and grid fields for over half an hour without vision. Using a simple HD error model, we show analytically that idiothetic path integration (iPI) alone cannot be used to maintain any stable place representation beyond two to three minutes. We then use a measure of place stability based on information theoretic principles to prove that featureless boundaries alone cannot be used to improve localization above chance level. Having shown that neither iPI nor boundaries alone are sufficient, we then address the question of whether their combination is sufficient and--we conjecture--necessary to maintain place stability for prolonged periods without vision. We addressed this question in simulations and robot experiments using a navigation model comprising of a particle filter and boundary map. The model replicates published experimental results on place field and grid field stability without vision, and makes testable predictions including place field splitting and grid field rescaling if the true arena geometry differs from the acquired boundary map. We discuss our findings in light of current theories of animal navigation and neuronal computation, and elaborate on

  1. A stab-and-roll biopsy technique to maintain gingival epithelium for desquamative gingivitis. (United States)

    Endo, Hiroyasu; Rees, Terry D; Allen, Edward P; Kuyama, Kayo; Aoki, Shinichiro; Yamamoto, Hirotsugu; Ito, Takanori


    Desquamative gingivitis (DG) is a clinical manifestation common to several diseases. It is known that most cases of DG are caused by mucous membrane pemphigoid (MMP), oral lichen planus (OLP), or pemphigus vulgaris (PV). Early recognition and treatment of these diseases can improve the prognosis, but diagnostic delays are common in patients with DG because obtaining a diagnostic biopsy is technically challenging. A biopsy technique designed to maintain the gingival epithelium for patients with DG was developed. The usefulness of this technique is discussed. This study is based on a retrospective review of 27 DG cases. A stab-and-roll technique was used to obtain gingival tissue. This technique is designed to reduce lateral forces on the epithelium during the procedure and to thereby prevent the inadvertent removal of the epithelium from the biopsy specimen. A total of 52 biopsies comprising 27 for hematoxylin and eosin (H&E)-stained samples and 25 for direct immunofluorescence (DIF) testing were reviewed. Fifty-one of the 52 biopsies (98.1%) maintained the epithelium. Only one biopsy (1.9%) showed that the epithelium was totally absent. Therefore, H&E and DIF features of 51 biopsies were analyzed. Definitive diagnoses of the diseases causing DG included MMP (13 cases), PV (eight cases), and OLP (six cases). A diagnostic biopsy was obtained from the gingiva of patients with DG using the stab-and-roll technique. The gingival epithelium was well maintained, and the relationship with the underlying connective tissue was diagnostic. In the future, this stab-and-roll biopsy technique may facilitate early diagnosis and treatment of diseases causing DG.

  2. Achieving and maintaining lung volume in the preterm infant: from the first breath to the NICU. (United States)

    Lista, Gianluca; Maturana, Andrés; Moya, Fernando R


    The main goal for the neonatologist is to facilitate the adaptation to extra-uterine life during initial transition, while minimizing lung injury opening and protecting the premature lung from the first breath onwards. An appropriate management from birth should lead to the achievement of an early functional residual capacity (FRC), and the following steps should aim at maintaining an adequate lung volume. To date, different strategies are available to optimize fetal-neonatal transition and promote lung recruitment. New ventilation approaches, such as sustained lung inflation (SLI) and "open lung strategy", well-established ventilation techniques with a more tailored application and less invasive modalities to administer surfactant have been recently introduced in clinical practice with promising results. given the current status of neonatal care, it seems that lung injury and BPD could be reduced with multiple strategies starting early in the delivery room. Literature underlines the importance of a respiratory tailored management of preterm infants from birth and during the whole NICU stay. What is Known: • Experimental and clinical studies have shown that the transition from fetal to adult type cardiorespiratory circulation needs an adequate lung ventilation. An appropriate management in the delivery room should lead to the achievement of an early FRC, and through the following steps, the neonatologist should aim at maintaining an adequate lung volume. • Literature underlines the importance of a respiratory tailored management of preterm infants during the whole NICU stay to maintain the benefits of a successful postnatal adaption. What is New: • Herewith, we describe the most relevant and recent interventions which can be performed from the delivery room to the NICU stay to guarantee an adequate tradition to postnatal life and an effective cardiorespiratory stability.

  3. Varenicline for smoking cessation among methadone-maintained smokers: a randomized clinical trial. (United States)

    Stein, M D; Caviness, C M; Kurth, M E; Audet, D; Olson, J; Anderson, B J


    With smoking rates far exceeding the general population, methadone-maintained (MMT) opiate-dependent smokers experience high rates of tobacco-related health consequences. Previous treatment studies have used nicotine replacement and produced low quit rates. We test, using a three-group randomized design, the efficacy of varenicline versus placebo, in comparison with nicotine replacement therapy (NRT) that combines nicotine patch prescription plus ad libitum nicotine rescue, for smoking cessation. We recruited methadone-maintained smokers from nine treatment centers in southern New England and provided six months of treatment, and a minimal behavioral intervention at baseline (NCI's 5A's). Outcomes included carbon monoxide (CO) confirmed 7-day point smoking cessation prevalence at 6 months and self-reported change in mean cigarettes per day. The 315 participants had a mean age of 40, with 50% male and 79% non-Hispanic White, smoked an average of 19.6 (± 10.4) cigarettes/day, and had a mean daily methadone dose of 109 mg. Intent-to-treat analyses, with missing considered to be smoking, showed the rate of CO-confirmed 7-day abstinence at 6-months was 5.4% overall, with varenicline 3.7% compared to placebo 2.2%, and NRT 8.3% (p>.05). Adherence rates during the 7-days immediately prior to 6-month assessment were 34.2% in varenicline, 34.4% in placebo, and 48.8% in NRT. Between baseline and 6-months there was an overall self-reported mean reduction of 8.3 cigarettes/day. Varenicline did not increase quit rates over placebo. Smoking cessation rates in methadone-maintained smokers are low and novel treatment strategies are required. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Optimization of culture conditions for maintaining porcine induced pluripotent stem cells. (United States)

    Gao, Yi; Guo, Yanjie; Duan, Anqin; Cheng, De; Zhang, Shiqiang; Wang, Huayan


    Ground state porcine induced pluripotent stem cells (piPSCs), which retain the potential to generate chimeric animal and germline transmission, are difficult to produce. This study investigated morphological and biological progression at the early stage of porcine somatic cell reprogramming, and explored suitable conditions to increase the induction efficiency of piPSCs. A cocktail of defined transcription factors was used to generate piPSCs. The amphotropic retrovirus, which carried human OCT4 (O), SOX2 (S), KLF4 (K), C-MYC (M), TERT (T), and GFP, were used to infect porcine embryonic fibroblasts (PEFs). The number of clones derived from OSKM (4F) and OSKMT (4F+T) was significantly higher than that from SKM (3F) and SKMT (3F+T), suggesting that OCT4 played a critical role in regulating porcine cell reprogramming. The number of alkaline phosphatase-positive clones from a medium with leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) (M1 medium) was significantly higher than that with insulin and 2i PD0325901/CHIR99021 (M2 medium), indicating that insulin and 2i could not effectively maintain piPSC propagation. In the M1 medium, piPSC lines could not maintain the typical self-renewal morphology on gelatin-coated and Matrigel-coated plates. Without the mouse embryonic fibroblast (MEF) feeder, piPSCs started to simultaneously differentiate. Based on the potential for self-renewal and activation of pluripotent markers, we found that the culture condition of 4F+T plus LIF and bFGF plus MEF feeder promoted PEF reprogramming more efficiently than the other conditions tested here. Two piPSC lines (IB-1 and IB-2) were derived and maintained for up to 20 passages in vitro.

  5. Entrepreneurs' self-reported health, social life, and strategies for maintaining good health. (United States)

    Gunnarsson, Kristina; Josephson, Malin


    This study investigated the association between self-reported good health and self-valued good social life. An additional aim was to examine entrepreneur's strategies for maintaining good health. The study design included a two-wave questionnaire, with five years between the surveys (2001 and 2006), and qualitative interviews. The study group consisted of 246 entrepreneurs from the central region of Sweden and represented ten different trades. Entrepreneurs reporting good health in both 2001 and 2006 were compared with entrepreneurs reporting poor health on both occasions or with inconsistent answers. Six of the entrepreneurs were strategically chosen for the interview study. Consistent good health was reported by 56% of the entrepreneurs. Good social life in 2001 was associated with an increased odds ratio (OR) for consistent good health when the analyses were adjusted for physical work conditions and job satisfaction (OR 2.12, 95% CI 1.07-4.17). Findings for good leisure time, weekly moderate physical exercise, and a rating of work being less or equally important as other life areas, were similar but not statistically significant when job satisfaction was considered in the analyses. Strategies for maintaining good health included good planning and control over work, flexibility at work, good social contact with family, friends and other entrepreneurs, and regular physical exercise. This study demonstrated an association between self-reported good health and good social life for entrepreneurs in small-scale enterprises. In addition, the entrepreneurs emphasised strategies such as planning and control over work and physical exercise are important for maintaining good health.

  6. Sea Hare Aplysia punctata (Mollusca: Gastropoda) Can Maintain Shell Calcification under Extreme Ocean Acidification. (United States)

    Carey, Nicholas; Dupont, Sam; Sigwart, Julia D


    Ocean acidification is expected to cause energetic constraints upon marine calcifying organisms such as molluscs and echinoderms, because of the increased costs of building or maintaining shell material in lower pH. We examined metabolic rate, shell morphometry, and calcification in the sea hare Aplysia punctata under short-term exposure (19 days) to an extreme ocean acidification scenario (pH 7.3, ∼2800 μatm pCO 2 ), along with a group held in control conditions (pH 8.1, ∼344 μatm pCO 2 ). This gastropod and its congeners are broadly distributed and locally abundant grazers, and have an internal shell that protects the internal organs. Specimens were examined for metabolic rate via closed-chamber respirometry, followed by removal and examination of the shell under confocal microscopy. Staining using calcein determined the amount of new calcification that occurred over 6 days at the end of the acclimation period. The width of new, pre-calcified shell on the distal shell margin was also quantified as a proxy for overall shell growth. Aplysia punctata showed a 30% reduction in metabolic rate under low pH, but calcification was not affected. This species is apparently able to maintain calcification rate even under extreme low pH, and even when under the energetic constraints of lower metabolism. This finding adds to the evidence that calcification is a largely autonomous process of crystallization that occurs as long as suitable haeomocoel conditions are preserved. There was, however, evidence that the accretion of new, noncalcified shell material may have been reduced, which would lead to overall reduced shell growth under longer-term exposures to low pH independent of calcification. Our findings highlight that the chief impact of ocean acidification upon the ability of marine invertebrates to maintain their shell under low pH may be energetic constraints that hinder growth of supporting structure, rather than maintenance of calcification.

  7. [Somatic constitution and the ability to maintain dynamic body equilibrium in girls practicing rhythmic gymnastics]. (United States)

    Poliszczuk, Tatiana; Broda, Daria


    The greatest similarities in body constitution were noted in competitors practising the same discipline. The similarities increase with the training level. A typical body constitution for a given discipline not only favourably affects athletic performance, but is also the factor preventing sportsrelated contusions. The ability to maintain body equilibrium, together with somatic constitution, are the basic selective criteria in rhythmic gymnastics. The objective of this paper was to determine somatotypes, to evaluate the ability to maintain dynamic body equilibrium in girls practicing rhythmic gymnastics and to develop model characteristics enabling early diagnosis of the disorders equilibrium system function. The sample comprised 19 girls aged 8-11 years, practising rhythmic gymnastics. For the evaluation of the competitors' somatotypes, the Heath-Carter method was used, based on the classic concept of Sheldon's body constitution components. Body equilibrium level was evaluated by means of posturography. The mean values of the endomorphic component I, mesomorphic component II and ectomorphic component III in the gymnasts were 2.65+/-1.29, 2.45+/-0.37 and 3.95+/-0.64 respectively. The mean body mass index (BMI) value for this cohort was 15.32, which means advanced slimness. The level of dynamic equilibrium is determined by the following mean values: the time of reaching the equilibrium, the way of reaching it and the duration of stay at the defined point. The model of above mentioned indicates was developed based on the analysis of it's best results. Body constitution type in the qualified gymnasts is characterised by the prevalence of the ectomorphic component. The study results indicate that female gymnasts are generally slim and lean. It is necessary to monitor BMI in order to exclude weight-related disorders and to observe the changes with age. The poorest result was found when the gymnasts bent in the backward direction as this body position is most difficult

  8. Orthostatic stress is necessary to maintain the dynamic range of cardiovascular control in space (United States)

    Baisch, J. F.; Wolfram, G.; Beck, L.; Drummer, C.; Stormer, I.; Buckey, J.; Blomqvist, G.


    In the upright position, gravity fills the low-pressure systems of human circulation with blood and interstitial fluid in the sections below the diaphragm. Without gravity one pressure component in the vessels disappears and the relationship between hydrostatic pressure and oncotic pressure, which regulates fluid passage across the capillary endothelium in the terminal vascular bed, shifts constantly. The visible consequences of this are a puffy face and "bird" legs. The plasma volume shrinks in space and the range of cardiovascular control is reduced. When they stand up for the first time after landing, 30-50% of astronauts suffer from orthostatic intolerance. It remains unclear whether microgravity impairs cardiovascular reflexes, or whether it is the altered volume status that causes the cardiovascular instability following space flight. Lower body negative pressure was used in several space missions to stimulate the cardiovascular reflexes before, during and after a space flight. The results show that cardiovascular reflexes are maintained in microgravity. However, the astronauts' volume status changed in space, towards a volume-retracted state, as measurements of fluid-regulating hormones have shown. It can be hypothesized that the control of circulation and body fluid homeostasis in humans is adapted to their upright posture in the Earth's gravitational field. Autonomic control regulates fluid distribution to maintain the blood pressure in that posture, which most of us have to cope with for two-thirds of the day. A determined amount of interstitial volume is necessary to maintain the dynamic range of cardiovascular control in the upright posture; otherwise orthostatic intolerance may occur more often.

  9. Contingency management for behavior change: Applications to promote brief smoking cessation among opioid-maintained patients (United States)

    Saulsgiver, Kathryn A.; Sigmon, Stacey C.


    Cigarette smoking is highly prevalent among patients who are being treated for opioid-dependence, yet there have been limited scientific efforts to promote smoking cessation in this population. Contingency management (CM) is a behavioral treatment that provides monetary incentives (available in the form of vouchers) contingent upon biochemical evidence of drug abstinence. This paper discusses the results of two studies that utilized CM to promote brief smoking cessation among opioid-maintained patients. Participants in a pilot study were randomly assigned for a 2-week period to a Contingent group that earned monetary vouchers for providing biochemical samples that met criteria for smoking abstinence, or a Noncontingent group that earned monetary vouchers independent of smoking status (Dunn et al., 2008). Results showed Contingent participants provided significantly more smoking-negative samples than Noncontingent participants (55% vs. 5%, respectively). A second randomized trial that utilized the same 2-week intervention and provided access to the smoking cessation pharmacotherapy bupropion replicated the results of the pilot study (55% and 17% abstinence in Contingent and Noncontingent groups, respectively). A nonsignificant trend suggested bupropion may have contributed to smoking abstinence (Dunn et al, 2010). For both studies high rates of relapse to smoking were observed after the intervention ended; however, the results compare favorably to previous pharmacological and behavioral smoking cessation interventions and provide evidence that opioid-maintained patients can achieve a brief period of continuous smoking abstinence. Relapse to illicit drug use was also evaluated prospectively and no evidence that smoking abstinence was associated with a relapse to illicit drug use was observed (Dunn et al., 2009). It will be important for future studies to evaluate participant characteristics that might predict better treatment outcome, to assess the contribution that

  10. Role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. (United States)

    Islam, M Sirajul; Islam, M Shafiqul; Mahmud, Zahid H; Cairncross, Sandy; Clemens, John D; Collins, Andrew E


    In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail:

  11. Does maintaining a bottle of adhesive without the lid significantly reduce the solvent content? (United States)

    Santana, Márcia Luciana Carregosa; Sousa Júnior, José Aginaldo de; Leal, Pollyana Caldeira; Faria-e-Silva, André Luis


    This study aimed to evaluate the effect of maintaining a bottle of adhesive without its lid on the solvent loss of the etch-and-rinse adhesive systems. Three 2-step etch-and-rinse adhesives with different solvents (acetone, ethanol or butanol) were used in this study. Drops of each adhesive were placed on an analytical balance and the adhesive mass was recorded until equilibrium was achieved (no significant mass alteration within time). The solvent content of each adhesive and evaporation rate of solvents were measured (n=3). Two bottles of each adhesive were weighted. The bottles were maintained without their lids for 8 h in a stove at 37 ºC, after which the mass loss was measured. Based on mass alteration of drops, acetone-based adhesive showed the highest solvent content (46.5%, CI 95%: 35.8-54.7) and evaporation rate (1.11 %/s, CI95%: 0.63-1.60), whereas ethanol-based adhesive had the lowest values (10.1%, CI95%: 4.3-16.0; 0.03 %/s CI95%: 0.01-0.05). However, none of the adhesives bottles exhibited significant mass loss after sitting for 8 h without their lids (% from initial content; acetone - 96.5, CI 95%: 91.8-101.5; ethanol - 99.4, CI 95%: 98.4-100.4; and butanol - 99.3, CI 95%: 98.1-100.5). In conclusion, maintaining the adhesive bottle without lid did not induce significant solvent loss, irrespective the concentration and evaporation rate of solvent.

  12. Maintaining and Enhancing Diversity of Sampled Protein Conformations in Robotics-Inspired Methods. (United States)

    Abella, Jayvee R; Moll, Mark; Kavraki, Lydia E


    The ability to efficiently sample structurally diverse protein conformations allows one to gain a high-level view of a protein's energy landscape. Algorithms from robot motion planning have been used for conformational sampling, and several of these algorithms promote diversity by keeping track of "coverage" in conformational space based on the local sampling density. However, large proteins present special challenges. In particular, larger systems require running many concurrent instances of these algorithms, but these algorithms can quickly become memory intensive because they typically keep previously sampled conformations in memory to maintain coverage estimates. In addition, robotics-inspired algorithms depend on defining useful perturbation strategies for exploring the conformational space, which is a difficult task for large proteins because such systems are typically more constrained and exhibit complex motions. In this article, we introduce two methodologies for maintaining and enhancing diversity in robotics-inspired conformational sampling. The first method addresses algorithms based on coverage estimates and leverages the use of a low-dimensional projection to define a global coverage grid that maintains coverage across concurrent runs of sampling. The second method is an automatic definition of a perturbation strategy through readily available flexibility information derived from B-factors, secondary structure, and rigidity analysis. Our results show a significant increase in the diversity of the conformations sampled for proteins consisting of up to 500 residues when applied to a specific robotics-inspired algorithm for conformational sampling. The methodologies presented in this article may be vital components for the scalability of robotics-inspired approaches.


    Directory of Open Access Journals (Sweden)

    V. O. Protsenko


    Full Text Available Purpose. The paper should consider lowering the labour input of maintenance of drive gears operation of vehicles power plants at the expense of working out the coupling construction having low duration of substitution of elastic element and a justification of its force, power and strength parameters. Methodology. During development of coupling construction with increased maintainability the criterion of minimum average labour input of its reconstruction has been used. Constructive-power parametres of coupling were defined with the use of classical methods and statics and calculus theorems. Simulation of couplings operation is executed by numerical methods for couplings of concrete executions with the use of modern program complexes. Findings. Authors developed the coupling with rope elastic elements having low labour input of elastic element substitution due to multiple-purpose construction of tightening elements and pins with open slots in which the rope sequentially can be included is developed. The dependences are received, allowing to define power loads of elements of a coupling, and also to execute selection of ropes and calculation of strength of tightening elements. With obtained dependence the coupling with rope elastic elements for substitution of coupling Vulkan propulsion plant of the bulk ship of the project 2-95А/R is calculated and designed. The integrated definition of time for rope substitution in the offered coupling with application of specifications has displayed that for execution of this process it is necessary to expend about 150 minutes of time that is much less than 530 mines necessary for substitution of elastic membranes of base coupling Vulkan. Originality. The estimation of the basic constructive, power and strenght parametres of coupling with face installation of a rope with increased maintainability is executed. Practical value. Construction of a coupling with increased maintainability equipped with rope elastic

  14. Maintaining power: women's experiences from labour onset before admittance to maternity ward. (United States)

    Carlsson, Ing-Marie; Ziegert, Kristina; Sahlberg-Blom, Eva; Nissen, Eva


    In Sweden pregnant women are encouraged to remain at home until the active phase of labour. Recommendation is based on evidence, that women who seek care and are admitted in the latent phase of labour are subjected to more obstetric interventions and suffer more complications than women who remain at home until the active phase of labour. The aim of this study was to obtain a deeper understanding of how women, who remain at home until the active phase of labour, experience the period from labour onset until admission to labour ward. Interviews were conducted with 19 women after they had given birth to their first child. A Constructivist Grounded theory method was used. 'Maintaining power' was identified as the core category, explaining the women's experience of having enough power, when the labour started. Four related categories: 'to share the experience with another', 'to listen to the rhythm of the body', 'to distract oneself' and 'to be encased in a glass vessel', explained how the women coped and thereby maintained power. The first time mothers in this study, who managed to stay at home during the latent phase of labour, had a sense of power that was expressed as a driving force towards the birth, a bodily and mental strength and the right to decide over their own bodies. This implies that women who maintain power have the ability to make choices during the birth process. The professionals need to be sensitive, supportive and respectful to women's own preferences in the health-care encounter, to promote the existing power throughout the birthing process. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. A Calcium-Dependent Plasticity Rule for HCN Channels Maintains Activity Homeostasis and Stable Synaptic Learning (United States)

    Honnuraiah, Suraj; Narayanan, Rishikesh


    Theoretical and computational frameworks for synaptic plasticity and learning have a long and cherished history, with few parallels within the well-established literature for plasticity of voltage-gated ion channels. In this study, we derive rules for plasticity in the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, and assess the synergy between synaptic and HCN channel plasticity in establishing stability during synaptic learning. To do this, we employ a conductance-based model for the hippocampal pyramidal neuron, and incorporate synaptic plasticity through the well-established Bienenstock-Cooper-Munro (BCM)-like rule for synaptic plasticity, wherein the direction and strength of the plasticity is dependent on the concentration of calcium influx. Under this framework, we derive a rule for HCN channel plasticity to establish homeostasis in synaptically-driven firing rate, and incorporate such plasticity into our model. In demonstrating that this rule for HCN channel plasticity helps maintain firing rate homeostasis after bidirectional synaptic plasticity, we observe a linear relationship between synaptic plasticity and HCN channel plasticity for maintaining firing rate homeostasis. Motivated by this linear relationship, we derive a calcium-dependent rule for HCN-channel plasticity, and demonstrate that firing rate homeostasis is maintained in the face of synaptic plasticity when moderate and high levels of cytosolic calcium influx induced depression and potentiation of the HCN-channel conductance, respectively. Additionally, we show that such synergy between synaptic and HCN-channel plasticity enhances the stability of synaptic learning through metaplasticity in the BCM-like synaptic plasticity profile. Finally, we demonstrate that the synergistic interaction between synaptic and HCN-channel plasticity preserves robustness of information transfer across the neuron under a rate-coding schema. Our results establish specific physiological roles

  16. Maintaining cell identity: PRC2-mediated regulation of transcription and cancer. (United States)

    Comet, Itys; Riising, Eva M; Leblanc, Benjamin; Helin, Kristian


    Enhancer of zeste homologue 2 (EZH2), the catalytic subunit of Polycomb repressive complex 2 (PRC2), has attracted broad research attention in the past few years because of its involvement in the development and maintenance of many types of cancer and the use of specific EZH2 inhibitors in clinical trials. Several observations show that PRC2 can have both oncogenic and tumour-suppressive functions. We propose that these apparently opposing roles of PRC2 in cancer are a consequence of the molecular function of the complex in maintaining, rather than specifying, the transcriptional repression state of its several thousand target genes.

  17. Hanford Site Guide for Preparing and Maintaining Fenerator Group Pollution Prevention Program Documentation

    Energy Technology Data Exchange (ETDEWEB)

    PLACE, B.G.


    This document provides guidance to generator groups for preparing and maintaining documentation of Pollution Prevention/Waste Minimization (P2/WMin) Program activities. The guidance is one of a hierarchical series that includes the Hanford Site Waste Minimization and Pollution Prevention Awareness Program Plan (DOE-RL, 1998a) and Prime Contractor implementation plans describing programs required by Resource Conservation and Recovery Act of 1976 (RCRA) 3002(b) and (300501) (RCRA and EPA, 1994). Documentation guidance for the following five P2/WMin elements are discussed: Fiscal Year (FY) Goals; Budget and Staffing; Waste Minimization (WMinn ) Assessments (WMAs); Pollution Prevention (P2) Reporting; WMin Certification.

  18. Cost-effectiveness of combustion turbines: recommendations for reliability, maintainability, supportability and maintenance requirements

    Energy Technology Data Exchange (ETDEWEB)

    Meuwisse, C.; Despujols, A. [Electricite de France, Research and Development Division, Chatou (France); Givaudan, B. [Electricite de France, Research and Development Division - SEPTEN, Villeurbanne (France); Lafage, L. [Electricite de France, Engineering and Construction Division - CNET, Paris (France)


    The profitability of combustion turbines intended for export is of extreme importance for Electricite de France. It is principally during the development phase of a project that one can ensure resect of two indissociable factors, essential to the per-kWh production cost: global operating costs and performance in terms of reliability and availability. The approach proposed here advocates the global acquisition of the installation and its logistic support. Generally applicable recommendations are given. They enable integrating in the future plant specifications all requirements relative to plant reliability, availability, maintainability and logistic support. They are structured according to type: expression of needs and management factors. (orig.) 4 refs.

  19. Spontaneous object recognition memory is maintained following transformation of global geometric properties. (United States)

    Poulter, Steven L; Kosaki, Yutaka; Easton, Alexander; McGregor, Anthony


    Studies of spontaneous behavior to assess memory are widespread, but often the relationships of objects to contexts and spatial locations are poorly defined. We examined whether object-location memory was maintained following global, but not local, changes to the geometric shape of an arena. Rats explored two trial-unique objects in a distinctively shaped arena before being exposed to two identical copies of one of these objects in a different shape in a different physical location. Rats preferentially explored objects that were novel in relation to their local geometric context rather than identifying both locations as novel in the global geometric context.

  20. Establishing, maintaining and modifying DNA methylation patterns in plants and animals (United States)

    Law, Julie A.; Jacobsen, Steven E.


    Cytosine DNA methylation is a stable epigenetic mark that is critical for diverse biological processes including gene and transposon silencing, imprinting, and X chromosome inactivation. Recent findings in plants and animals have greatly increased our understanding of the pathways utilized to accurately target, maintain, and modify patterns of DNA methylation and have revealed unanticipated mechanistic similarities between these organisms. Key roles for small RNAs, proteins with methylated DNA binding domains and DNA glycosylases in these processes have emerged. Drawing on insights from both plants and animals should deepen our understanding of the regulation and biological significance of DNA methylation. PMID:20142834