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Sample records for straightening

  1. Hair straightener poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002706.htm Hair straightener poisoning To use the sharing features on this page, please enable JavaScript. Hair straightener poisoning occurs when someone swallows products that ...

  2. Hair straightener poisoning

    MedlinePlus

    ... relaxer/straightener products that do not use lye) Mineral oil Polyethylene glycol Sodium hydroxide (found in relaxer/ ... ed. Philadelphia, PA: Elsevier Saunders; 2007:chap 100. Wax PM, Young A. Caustics. In: Marx JA, Hockberger ...

  3. Holder for Straightening Bent Tubes

    NASA Technical Reports Server (NTRS)

    Turner, A. R.; Polzien, E. D.

    1985-01-01

    One-piece holder restrains bent metal tube against further bending during straightening operation. Holder consists of handle 16 in. (41 cm) long welded to short, strong tube that fits around tube to be straightened.

  4. Straightening: existence, uniqueness and stability

    PubMed Central

    Destrade, M.; Ogden, R. W.; Sgura, I.; Vergori, L.

    2014-01-01

    One of the least studied universal deformations of incompressible nonlinear elasticity, namely the straightening of a sector of a circular cylinder into a rectangular block, is revisited here and, in particular, issues of existence and stability are addressed. Particular attention is paid to the system of forces required to sustain the large static deformation, including by the application of end couples. The influence of geometric parameters and constitutive models on the appearance of wrinkles on the compressed face of the block is also studied. Different numerical methods for solving the incremental stability problem are compared and it is found that the impedance matrix method, based on the resolution of a matrix Riccati differential equation, is the more precise. PMID:24711723

  5. Guide for extrusion dies eliminates straightening operation

    NASA Technical Reports Server (NTRS)

    Gyorgak, C. A.; Hoover, R. J.

    1964-01-01

    To prevent distortion of extruded metal, a guidance assembly is aligned with the die. As the metal emerges from the extrusion dies, it passes directly into the receiver and straightening tube system, and the completed extrusion is withdrawn.

  6. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast...

  7. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are...

  8. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast...

  9. 18. VIEW OF ROLLER LEVELER USED TO STRAIGHTEN AND FLATTEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF ROLLER LEVELER USED TO STRAIGHTEN AND FLATTEN METAL SHEETS. (7/2/86) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  10. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are...

  11. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are...

  12. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast...

  13. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are...

  14. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are...

  15. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast...

  16. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast...

  17. 6. VIEW OF FIVEFOOT WIND TUNNEL WITH AIR STRAIGHTENER AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF FIVE-FOOT WIND TUNNEL WITH AIR STRAIGHTENER AND OPERATOR STATION IN FOREGROUND (1991). - Wright-Patterson Air Force Base, Area B, Building No. 19, Five-Foot Wind Tunnel, Dayton, Montgomery County, OH

  18. Flow Straightener for a Rotating-Drum Liquid Separator

    NASA Technical Reports Server (NTRS)

    O'Coin, James R.; Converse, David G.; Rethke, Donald W.

    2004-01-01

    A flow straightener has been incorporated into a rotary liquid separator that originally comprised an inlet tube, a shroud plate, an impeller, an inner drum, an outer drum, a housing, a pitot tube, and a hollow shaft motor. As a consequence of the original geometry of the impeller, shroud, inner drum, and hollow shaft, swirl was created in the airflow inside the hollow shaft during operation. The swirl speed was large enough to cause a significant pressure drop. The flow straightener consists of vanes on the back side of the shroud plate. These vanes compartmentalize the inside of the inner drum in such a way as to break up the flow path and thereby stop the air from swirling; as a result, the air enters the hollow shaft with a predominantly axial velocity instead of a swirl. Tests of the rotary liquid separator at an airflow rate of 10 cu ft/min (0.0047 cu m/s) revealed that the dynamic pressure drop was 8 in. of water (approx.=2 kPa) in the absence of the flow straightener and was reduced to 1 in. of water (approx.=0.25 kPa) in the presence of the flow straightener.

  19. Autonomic straightening of gravitropically curved cress roots in microgravity.

    PubMed

    Stankovic, B; Antonsen, F; Johnsson, A; Volkmann, D; Sack, F D

    2001-01-01

    The typical response of plant organs to gravistimulation is differential growth that leads to organ bending. If the gravitropic stimulus is withdrawn, endogenous compensation of the graviresponse and subsequent straightening occur in some plants. For instance, autonomic straightening of Lepidium roots occurs when gravitropically-curved rootsare rotated on a clinostat (Stankovi et al., 1998a). To determine whether endogenous compensation of the graviresponse also occurs in space, microgravity-grown cress roots were laterally centrifuged in-flight and then returned to microgravity using Biorack hardware on a shuttle mission (STS-81). The cress roots were centrifuged at 4 different g-doses (0.1 x g and 1 x g for 15 or 75 min). All four treatments yielded varying degrees of root curvature. Upon removal from the centrifuge, roots in all four treatments underwent subsequent straightening in microgravity. This straightening resulted from a loss of gravitropic curvature in older regions of the root and the coordinated alignment of new growth. These results show that both microgravity and clinostat rotation on Earth are equivalent in stimulus withdrawal with respect to the induction of endogenous compensation of the curvature. Cress roots are the only plant organ shown to undergo compensation of the curvature in both microgravity and on a clinostat. The compensation of graviresponse in space rules out the hypothesis that the endogenous root straightening ("autotropism") represents a commitment to a pre-stimulus orientation with respect to gravity and instead suggests that there is a default tendency towards axiality following a withdrawal of a g-stimulus. PMID:11594376

  20. Suspended, straightened carbon nanotube arrays by gel chapping.

    PubMed

    Ji, Chunyan; Li, Hongbian; Zhang, Luhui; Liu, Yu; Li, Yan; Jia, Yi; Li, Zhen; Li, Peixu; Shi, Enzheng; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Cao, Anyuan

    2011-07-26

    We report large-scale self-assembly of suspended, straightened, single-walled carbon nanotubes (SWNTs) across regular TiO(2) gel islands. By coating a SWNT network on top of a pool of the TiO(2) colloid and inducing a rapid drying and chapping process, initially curled, random SWNTs can be straightened into aligned arrays and suspended across the island gaps. The suspended SWNT arrays were grafted by semiconducting or metallic nanoparticles, resulting in hybrid structures with tailored and neat morphology, and enhanced photoresponse. We further demonstrate these suspended SWNTs can sustain high speed gas blowing (up to 20 m per second) reversibly for hundreds of cycles, and detect gas velocity by the resistance change. PMID:21699200

  1. PROCESSING OF NANOSTRUCTURED COPPER BY REPETITIVE CORRUGATION AND STRAIGHTENING (RCS)

    SciTech Connect

    Zhu, Y.T.; Jiang, H.

    2000-10-01

    A new process, Repetitive Corrugation and Straightening (RCS), has been developed to create bulk, nanostructured copper. In this investigation, a high purity (99.99%). copper bar measuring 6 x 6 x 50 mm with an average grain size of 765 {micro}m was used as the starting material. It was repetitively corrugated and straightened for 14 times with 90{degree} rotations along its longitudinal axis between consecutive corrugation-straightening cycles. The copper was cooled to below room temperature before each RCS cycle. The grain size obtained after the RCS process was in the range of twenty to a few hundred nanometers, and microhardness was increased by 100%. Both equilibrium and non-equilibrium grain boundaries are observed. This work demonstrates the capability of the RCS process in refining grain size of metal materials. The RCS process can be easily adapted to large-scale industrial production and has the potential to pave the way to large-scale structural applications of nanostructured materials.

  2. Vision system for gauging and automatic straightening of steel bars

    NASA Astrophysics Data System (ADS)

    Sidla, Oliver; Wilding, Ernst; Niel, Albert; Barg, Herbert

    2001-02-01

    A machine vision application for the fully automatic straightening of steel bars is presented. The bars with lengths of up to 6000 mm are quite bent on exit of the rolling mill and need to be straightened prior to delivery to a customer. The shape of the steel bar is extracted and measured by two video resolution cameras which are calibrated in position and viewing angle relative to a coordinate system located in the center of the roller table. Its contour is tracked and located with a dynamic programming method utilizing several constraints to make the algorithm as robust as possible. 3D camera calibration allows the transformation of image coordinates to real-world coordinates. After smoothing and spline fitting the curvature of the bar is computed. A deformation model of the effect of force applied to the steel allows the system to generate press commands which state where and with what specific pressure the bar has to be processed. The model can be used to predict the straightening of the bar over some consecutive pressing events helping to optimize the operation. The process of measurement and pressing is repeated until the straightness of the bar reaches a predefined limit.

  3. A conjecture of Procesi and the straightening algorithm of Rota.

    PubMed Central

    Allen, E E

    1992-01-01

    Let R = Q[x1, x2,..., xn] and R* denote the quotient of R by the ideal generated by the elementary symmetric functions. R*, under the action of Sn, yields a graded version of the left regular representation. Procesi asked for a basis of R* consisting of homogeneous polynomials Gamma[S, C] indexed by pairs of tableaux, with S standard and C cocharge, that exhibits the decomposition of R* into its irreducible components. Procesi also suggested a way to construct the Gamma[S, C]. Using Rota's straightening algorithm, I show that certain polynomials [S, C] closely related to the Gamma[S, C] terms yield the desired basis. Parallel to the ring R* there is a family of Sn-modules R that have recently been studied by Garsia and Procesi. These modules have a graded character that is closely related to the q-Kostka-Foulkes polynomials Klambdamu(q). The [S, C] can be shown to yield also a basis when restricted to a given R. Through this connection the work reported here leads to an additional way of proving the charge interpretation for the polynomials Klambdamu(q). PMID:11607289

  4. Straightening tubular flow for side-by-side visualization.

    PubMed

    Angelelli, Paolo; Hauser, Helwig

    2011-12-01

    Flows through tubular structures are common in many fields, including blood flow in medicine and tubular fluid flows in engineering. The analysis of such flows is often done with a strong reference to the main flow direction along the tubular boundary. In this paper we present an approach for straightening the visualization of tubular flow. By aligning the main reference direction of the flow, i.e., the center line of the bounding tubular structure, with one axis of the screen, we are able to natively juxtapose (1.) different visualizations of the same flow, either utilizing different flow visualization techniques, or by varying parameters of a chosen approach such as the choice of seeding locations for integration-based flow visualization, (2.) the different time steps of a time-dependent flow, (3.) different projections around the center line , and (4.) quantitative flow visualizations in immediate spatial relation to the more qualitative classical flow visualization. We describe how to utilize this approach for an informative interactive visual analysis. We demonstrate the potential of our approach by visualizing two datasets from two different fields: an arterial blood flow measurement and a tubular gas flow simulation from the automotive industry. PMID:22034324

  5. Comparison of Nozzle and Flow Straighteners for Tank Waste Sluicing Applications Letter Report

    SciTech Connect

    Mullen, O Dennis; Jackson, David R.

    2000-09-29

    Nozzles and flow straighteners were compared to assess the relative quality of the water streams for sluicing waste from underground storage tankes. The criteria for comparison were 1) the impact force produced by the streams over a range of distance from the nozzle impinging on target plates, and 2) the coherence of the streams as manifest by the variation of force on targets of two different sizes. It was determined that 1) the standard Hanford flow straightener is measurable less effective than a commercial firefighting flow straightener at producing a coherent stream when used with the standard Hanford nozzle, and 2) a lighter and more compact firefighting deluge nozzle will deliver a stream of equal quality to that from the Hanford nozzle when either nozzle is used with the commercial flow straightener.

  6. Progressive hair straightening using an automated flat iron: function of silicones.

    PubMed

    Dussaud, Anne; Rana, Bhavna; Lam, Hui Tung

    2013-01-01

    An automated hair iron was built with which the hair temperature, contact force of the iron against the hair tress, and gliding speed were controlled. The changes in keratin were characterized by several techniques including differential scanning calorimetry, birefringence measurements, and wet tensile tests. Undamaged curly hair was ironed for several iron cycles at temperatures ranging from 120°C to 175°C and washed between each iron cycle. Irreversible straightening of curly hair was observed and depended on the temperature and the number of cycles. The birefringence data suggested that the straightening was related to a gradual decrease of the microfilament organization. Silicone treatment did not significantly affect the course of microfilament denaturation, but it improved the quality of straightening. It enhanced the fiber alignment under the gliding action of the iron. Progressive thermal straightening may be a promising method to achieve permanent smoothing of curly hair without chemical treatment. Ironing at the onset temperature (∼154°C), before substantial disulfide bond scission occurred, seemed to be a good compromise between process speed, straightening performance, and hair integrity (i.e., reduced loss of cross-linking). PMID:23578835

  7. Method for producing ultrafine-grained materials using repetitive corrugation and straightening

    DOEpatents

    Zhu, Yuntian T.; Lowe, Terry C.; Jiang, Honggang; Huang, Jianyu

    2001-01-01

    A method of refining the grain structure and improving the hardness and strength properties of a metal or metal alloy workpiece is disclosed. The workpiece is subjected to forces that corrugate and then straighten the workpiece. These steps are repeated until an ultrafine-grained product having improved hardness and strength is produced.

  8. HEU Holdup Measurements in the 321-M Draw Bench, Straightener, and Fluoroscope Components

    SciTech Connect

    Dewberry, R.A.

    2001-07-10

    The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facilities Disposition Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. This report covers holdup measurements of uranium residue on the draw bench, straightener, and the fluoroscope components of the 321-M facility.

  9. Hemodynamic Effects of Stent Struts versus Straightening of Vessels in Stent-Assisted Coil Embolization for Sidewall Cerebral Aneurysms

    PubMed Central

    Kono, Kenichi; Shintani, Aki; Terada, Tomoaki

    2014-01-01

    Background Recent clinical studies have shown that recanalization rates are lower in stent-assisted coil embolization than in coiling alone in the treatment of cerebral aneurysms. Objective This study aimed to assess and compare the hemodynamic effect of stent struts and straightening of vessels by stent placement on reducing flow velocity in sidewall aneurysms, with the goal of reducing recanalization rates. Methods We evaluated 16 sidewall aneurysms treated with Enterprise stents. We performed computational fluid dynamics simulations using patient-specific geometries before and after treatment, with or without stent struts. Results Stent placement straightened vessels by a mean (±standard deviation) of 12.9°±13.1° 6 months after treatment. Placement of stent struts in the initial vessel geometries reduced flow velocity in aneurysms by 23.1%±6.3%. Straightening of vessels without stent struts reduced flow velocity by 9.6%±12.6%. Stent struts had significantly stronger effects on reducing flow velocity than straightening (P = 0.004, Wilcoxon test). Deviation of the effects was larger by straightening than by stent struts (P = 0.01, F-test). The combination of stent struts and straightening reduced flow velocity by 32.6%±12.2%. There was a trend that larger inflow angles produced a larger reduction in flow velocity by straightening of vessels (P = 0.16). Conclusion In sidewall aneurysms, stent struts have stronger effects (approximately 2 times) on reduction in flow velocity than straightening of vessels. Hemodynamic effects by straightening vary in each case and can be predicted by inflow angles of pre-operative vessel geometry. These results may be useful to design a treatment strategy for reducing recanalization rates. PMID:25247794

  10. Influence of thermal hair straightening on cannabis and cocaine content in hair.

    PubMed

    Ettlinger, Jana; Yegles, Michel

    2016-08-01

    It has been shown that cosmetic treatment like bleaching and perming may lead to an important decrease of drugs of abuse content in hair. Currently, hair straightening has become a regular hair treatment especially for women. The aim of this preliminary study was to investigate the effect of in vitro treatment of hair with heat straightener on cannabis and cocaine concentrations in hair. 17 positive cannabis and 7 positive cocaine hair samples were treated in vitro with a hair straightener. During this treatment hair was put sequentially 30 times in contact with heated iron plates at 200°C during 2s corresponding to a total time of contact of 1min. THC and Cannabinol (CBN) were analysed in cannabis positive hair and cocaine, benzoylecgonin (BZE) and cocaethylene were analysed in cocaine positive hair. Analyses were performed with routine methods using GC/MS in electron impact mode. Regarding cannabis results a decrease of THC concentrations was found in 11 of 17 hair samples after thermal treatment, whereas in 6 cases an increase was shown. In all the hair samples CBN concentrations was explicitly higher after the in vitro treatment. Regarding cocaine results cocaine and cocaethylene concentrations decreased after treatment in all seven hair samples; in contrast, higher concentrations of BZE were determined. The strong increase of CBN and BZE content in hair after thermal treatments may be due to the fact that THC is converted by heat into CBN and cocaine into BZE, thus changing the respective ratios of the analysed substances. In conclusion, thermal straightening should be considered as other cosmetic hair treatments for a correct interpretation of hair results. PMID:26826847

  11. Influence of thermal hair straightening on ethyl glucuronide content in hair.

    PubMed

    Ettlinger, Jana; Kirchen, Luc; Yegles, Michel

    2014-06-01

    Hair analysis of ethyl glucuronide (EtG) has become a valuable marker for the detection of moderate and chronic alcohol consumption. It has been shown that bleaching and perming may decrease EtG content in hair. So far, no studies exist about the influence of thermal hair straightening on EtG content in hair. Forty-one positive EtG hair samples were treated in vitro with a hair straightener at 200°C. Duration of treatment of 1 min was chosen for this study. After washing, pulverization, incubation in ultrasonic bath, solid-phase extraction, and derivatization with heptafluorobutyric anhydride, EtG was determined by gas chromatography-mass spectrometry - negative ion chemical ionization (GC-MS-NICI). The EtG contents in straightened hair strands were then compared with those in the corresponding untreated strands. In 20 of 41 hair samples, a decrease of EtG content was found ranging from 0.7% to 79.3% (average 20%) whereas in 21 cases an increase was shown ranging from 2.0% to 50.9% (average 15%). The variation of the results seems to depend on hair colour. The decrease may be explained by thermic in vitro destruction of EtG. The increase may be explained by denaturation of the hair matrix by thermal treatment possibly causing a better extraction of EtG during incubation in ultrasonic bath. This in vitro study indicates that thermal hair straightening has an impact on the EtG content in hair. This has to be considered for a correct interpretation of EtG results in hair. However, these results should be confirmed by in vivo studies. PMID:24817051

  12. Formaldehyde in hair straightening products: rapid ¹H NMR determination and risk assessment.

    PubMed

    Monakhova, Yulia B; Kuballa, Thomas; Mildau, Gerd; Kratz, Evamaria; Keck-Wilhelm, Andrea; Tschiersch, Christopher; Lachenmeier, Dirk W

    2013-04-01

    Despite official regulations, the illegal use of formaldehyde-containing or releasing hair straightening products has become a popular practice in Europe and high contents of formaldehyde in such products have been reported. In this study, a methodology utilizing (1)H NMR spectroscopy has been developed to measure the concentration of formaldehyde in hair straightening products. For sample preparation, a dilution and alkaline hydrolysis is required. The total formaldehyde content can then be quantified by a distinct peak of the CH2 group of the methanediol molecule in the δ4.84-4.82 ppm range. The developed methodology was applied for the analysis of 10 hair straightening products. Seven of these products contained detectable amounts of formaldehyde that were higher than the maximum allowed concentration of 0.2%. The formaldehyde content of these products was found to be in the range 0.42-5.83% with an average concentration of 1.46%. The accuracy and reliability of the NMR results were confirmed by the EU reference photometric method. The air formaldehyde concentrations after application of hair straightening products were estimated in ranges 20-423 ppm and 1-18 ppm (for 1 and 24 m(3) salon volume). A probabilistic exposure estimation using Monte Carlo simulation found the average formaldehyde concentration to be 6 ppm (standard deviation 15 ppm). All exposure scenarios considerably exceeded the safe level of 0.1 ppm. Our findings confirmed that the risk of cosmetic formulations with formaldehyde above 0.2% is not negligible, as these products may facilitate considerable exposure of formaldehyde for consumers especially for salon workers. PMID:23216202

  13. Effect of Patency File on Transportation and Curve Straightening in Canal Preparation with ProTaper System

    PubMed Central

    Hasheminia, Seyed Mohsen

    2013-01-01

    The aim of this ex vivo study was to evaluate the effect of using a patency file on apical transportation and curve straightening during canal instrumentation with the ProTaper rotary system. Seventy permanent mandibular first molars with mesiobuccal canals, measuring 18–23 mm in length and with a 25–40° curvature (according to the Schneider method), were selected. The working lengths were determined and the teeth were mounted and divided into two experimental groups: (A) prepared by the ProTaper system without using a patency file (n = 35) and (B) prepared by the ProTaper system using a patency file (n = 35). Radiographs taken before and after the preparation were imported into Photoshop software and the apical transportation, and curve straightening were measured. Data were analyzed using independent t-test. Partial correlation analysis was performed to evaluate the relationship between the initial curvature, transportation, and curve straightening (α = 0.05). Using a patency file during canal preparation significantly decreased both apical transportation and curve straightening (P < 0.001). There were significant relationships between the angle of curvature, transportation and curve straightening in pairs (P < 0.001). Apical patency is recommended during root canal preparation with the ProTaper rotary system. PMID:24159390

  14. Gravitropism of oat and wheat coleoptiles: dependence on the stimulation angle and involvement of autotropic straightening.

    PubMed

    Tarui, Y; Iino, M

    1997-12-01

    Gravitropism of oat (Avena sativa L.) and wheat (Triticum aestivum L.) coleoptiles was investigated in relation to the displacement angle or to the initially set stimulation angle (SA). We measured curvature rates at the early phase of curvature, before it was affected by the drop in SA resulting from the curvature response itself. The plot of the rates against the sines of initial SAs revealed similar curves for oats and wheat, which approached saturation as the sine increased to unity. The two species and previously analyzed rice [Iino et al. (1996) Plant Cell Environ. 19: 1160] appeared to have similar gravisensitivities. Initial SAs below and over 90 degrees yielded comparable rates when the sine values were the same, indicating that the extent of gravitropism is determined by the gravity component perpendicular to the organ's long axis. Long-term curvature kinetics at different SAs indicated that the net curvature rate dropped sharply before the tip reached the vertical position and then the tip approached the vertical slowly, with clear oscillatory movements in the case of wheat. During this late curvature phase, the coleoptile straightened gradually, although none of its parts had yet reached the vertical. When rotated on horizontal clinostats or displaced upwards to reduce SA in the late curvature phase, coleoptiles bent in the opposite direction. These results demonstrated that autotropism counteracts gravitropism to straighten coleoptiles. PMID:11536867

  15. Influence of chemical straightening on the stability of drugs of abuse in hair.

    PubMed

    Pritchett, Jeanita S; Phinney, Karen W

    2015-01-01

    Chemical straightening, also known as a relaxer, is ubiquitously used among African American women to obtain straighter hair compared with their natural tresses. This study focused on the stability of drugs of abuse in hair after a single application of the relaxer. Commercially available 'Lye' or 'No-Lye' chemical straightening products (Silk Elements™) were applied in vitro to drug-fortified hair (standard reference materials (SRM) 2379 and 2380) and hairs clipped from established drug users. Target analytes (cocaine (COC), benzoylecgonine (BZE), cocaethylene (CE), phencyclidine and tetrahydrocannabinol) were isolated using solid-phase extraction and then analyzed with isotope dilution gas chromatography-mass spectrometry with selective ion monitoring. After either treatment, drug concentrations were significantly (P < 0.05) decreased in both the SRM sample and the hair from authentic abusers. In the SRM groups, 6-67% of the original concentration remained after a single chemical treatment. Similarly, only 5-30% of the original concentration remained in authentic drug hairs that had formerly tested positive for COC, BZE and CE. PMID:25298521

  16. Three-Dimensional Analysis of Spiny Dendrites Using Straightening and Unrolling Transforms

    PubMed Central

    Morales, Juan; Benavides-Piccione, Ruth; Pastor, Luis; Yuste, Rafael; DeFelipe, Javier

    2014-01-01

    Current understanding of the synaptic organization of the brain depends to a large extent on knowledge about the synaptic inputs to the neurons. Indeed, the dendritic surfaces of pyramidal cells (the most common neuron in the cerebral cortex) are covered by thin protrusions named dendritic spines. These represent the targets of most excitatory synapses in the cerebral cortex and therefore, dendritic spines prove critical in learning, memory and cognition. This paper presents a new method that facilitates the analysis of the 3D structure of spine insertions in dendrites, providing insight on spine distribution patterns. This method is based both on the implementation of straightening and unrolling transformations to move the analysis process to a planar, unfolded arrangement, and on the design of DISPINE, an interactive environment that supports the visual analysis of 3D patterns. PMID:22644869

  17. Nanobubbles stability and multiwall carbon nanotubes straightening on few-layer graphene surfaces

    NASA Astrophysics Data System (ADS)

    Al-Harthi, S. H.; Al-Barwani, M.; Elzain, M.; Al-Naamani, N.; Hysen, T.

    2011-08-01

    The formation of nanobubbles, straightening, and orientation of multiwalled carbon nanotubes (MWCNTs) are investigated by preparing thin films employing dip casting of colloidal solutions on few-layer graphene (FLG) surfaces. In contrast to what is known, it is observed that nanobubbles are formed on an ultrathin dewetted layer of 0.5 nm thickness and exhibit unusual stability at ultrahigh vacuum conditions. Further, nanobubble rings are observed at atmospheric pressure. The results provide direct experimental evidence of the interaction between MWCNTs and nanobubbles at air-liquid-solid triple contact line and at lower step edge of the FLG, which together lead to the alignment of MWCNTs. Due to the balance between the surface tension forces and the strain forces arising from tube bending, MWCNTs attained straight rod-like shape. This enabled us to evaluate the elastic modulus of the MWCNT as E = 0.9 TPa.

  18. Active self-correction of back posture in children instructed with 'straighten your back' command.

    PubMed

    Czaprowski, Dariusz; Pawłowska, Paulina; Stoliński, Lukasz; Kotwicki, Tomasz

    2014-10-01

    The ability to adopt the properly corrected body posture is one of the factors determining the effectiveness of therapeutic programmes. This study determined the active self-correction expressed by the change of sagittal spinal curvatures (in standing and sitting positions) in 249 children (136 females, 113 males, aged 10-14 years) instructed with 'straighten your back' command (SYB). Spinal curvatures (sacral slope-SS, lumbar lordosis-LL, global, lower and upper thoracic kyphosis-TK, LK, UK, respectively) were assessed using Saunders inclinometer. The assessment was done in spontaneous standing and sitting positions and in the positions adopted after the SYB. In a standing position SYB led to the significant (P < 0.001) increase in SS, and the significant (P < 0.01) decrease in LL, TK, LK, UK. In a sitting position SYB led to significant changes (P < 0.001) from kyphotic to lordotic position of SS and LL and to the significant (P < 0.001) reduction of TK (36.5° ± 10.8 vs. 23.5° ± 11) and the flattening of LK (15.2° ± 8.7 vs. 1.0° ± 8.4). There were gender-based discrepancy regarding active self-correction only for LL in a standing and UK in a sitting position. Females demonstrated a significant decrease in LL (P < 0.001). UK significantly increased only in males (P < 0.001). The 'straighten your back' command leads to moving the spine away from mid-range towards end range of motion. Therefore, the command should not be used to elicit the most optimal back posture. Further studies are needed to determine if the active self-correction is different in females and males. PMID:24246905

  19. Assessment of Management Strategies for a Straightened Lowland Agricultural Stream in Southwestern Québec

    NASA Astrophysics Data System (ADS)

    Rousseau, Y.; Biron, P.

    2009-05-01

    Channel straightening and dredging were extensively used in the 20th century to improve agricultural fields' drainage efficiency and facilitate crop maintenance and harvest. Although the adverse geomorphologic and ecological effects of this practice on hydrologic networks are widely acknowledged, alternative management strategies remain marginal in Southwestern Québec. Furthermore, bank stabilization projects are often carried out to mitigate erosion at a local scale with little concern about the watershed scale, i.e. treating the symptom rather than the cause of erosion, and with little guidance on suitable designs for specific areas. We present here the results of a case study conducted in a small straightened agricultural stream in the St. Lawrence Lowlands (Richer stream, 45 km east of Montreal, Qc) to assess the efficiency of diverse instream structures to enhance bank stability. The loss in sinuosity and resultant increase in stream power in this stream resulted in acute erosion problems. A conceptual model developed in Java was developed to examine erosion processes at the watershed scale. This model is also used to parameterize a three-dimensional computational fluid dynamics model (Phoenics) to investigate the effects on flow field of employing various types of instream structures in a section of the Richer Stream which is particularly problematic for river management because of residential development and very limited space available for riparian zones. Model validation was achieved using flow velocity measurements obtained with an Acoustic Doppler Velocimeter. Simulation outcomes are analysed with regards to strategies using geomorphological, economical and ecological criteria in an attempt to identify their efficiency. The methods presented here can help decreasing the high degree of uncertainty generally involved in restoration activities by better assessing the efficiency of specific stabilization techniques prior to their implementation while

  20. Transmembrane helix straightening and buckling underlies activation of mechanosensitive and thermosensitive K(2P) channels.

    PubMed

    Lolicato, Marco; Riegelhaupt, Paul M; Arrigoni, Cristina; Clark, Kimberly A; Minor, Daniel L

    2014-12-17

    Mechanical and thermal activation of ion channels is central to touch, thermosensation, and pain. The TRAAK/TREK K(2P) potassium channel subfamily produces background currents that alter neuronal excitability in response to pressure, temperature, signaling lipids, and anesthetics. How such diverse stimuli control channel function is unclear. Here we report structures of K(2P)4.1 (TRAAK) bearing C-type gate-activating mutations that reveal a tilting and straightening of the M4 inner transmembrane helix and a buckling of the M2 transmembrane helix. These conformational changes move M4 in a direction opposite to that in classical potassium channel activation mechanisms and open a passage lateral to the pore that faces the lipid bilayer inner leaflet. Together, our findings uncover a unique aspect of K(2P) modulation, indicate a means for how the K(2P) C-terminal cytoplasmic domain affects the C-type gate which lies ∼40Å away, and suggest how lipids and bilayer inner leaflet deformations may gate the channel. PMID:25500157

  1. Analytical treatment of electron trajectory straightener issues in free-electron lasers

    SciTech Connect

    Elliott, C.J.; Quimby, D.C.; Spectra Technology, Inc., Bellevue, WA )

    1989-01-01

    The poincare orbit of the electron's journey must be straight and narrow through a many period FEL. To utilize an available technology level, the straightest wiggler orbit operating point (SWOOP) is chosen by adjusting the spacing parameter of an orbit correction scheme. This eases the requirements for achieving the full potential of FEL wigglers. One quality index, one cost index, two quality factors, two measures of field noise, an improvement index, and a straightener classification scheme are concepts that facilitate the analysis. Only when the field noise is large, is this analysis of direct use. A reader-friendly description culminates in the comparison of two schemes to illustrate the methods. Two coupled first order langevin equations have solutions that are proven to be gaussian variables. The solutions are used to give the required cross correlations. These results are coupled with a simple graphical technique and give an expression for the angular variance in the correction corridor. The two components of this variance are compared to a fiducial scheme and yield the two quality factors from which the quality, improvement and cost indices are computed. 68 refs., 5 figs.

  2. Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2008-10-01

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  3. Adolescent Idiopathic Scoliosis: A 71 Cases Study Ascertaining that Straightening Is Possible, and a New Etiological Hypothesis

    PubMed Central

    2013-01-01

    Study Design Seventy-one children (23 boys and 48 girls, aged 6 to 18 year-old) with adolescent idiopathic scoliosis (AIS) between 11° and 62°, without braces, have been treated manually, only at the level of the neck. Purpose To ascertain that non-surgical straightening of AIS is possible (without brace). Overview of Literature So far no disease modifying treatment for AIS existed. Braces can only slow down worsening (and this can only be achieved if they are worn 23 hours a day). Surgery is not without important risks. Methods All patients have been treated exclusively with a manual therapy called Brachy-Myotherapy. This method treats spasmed (contractured) muscles by placing them in a shortening position according to a specific protocol. Results An average straightening of 8° of AIS was observed, with a maximum of 25°. 94% of cases improved, 67 out of 71. The worst prognosis was, the better results. The more advanced AIS was, the better the results. Conclusions A simple and reliable treatment of AIS is possible. AIS seems to be a compensation mechanism of the body, with the aim of keeping the ears, and thus the labyrinths, at a horizontal level for correct equilibrium. When lasting post-traumatic neck muscle contractures causing a permanent side-bending of the skull have been treated, this compensation mechanism becomes irrelevant and scoliosis tends to subside. PMID:24353844

  4. Environmental and biological monitoring of occupational formaldehyde exposure resulting from the use of products for hair straightening.

    PubMed

    Peteffi, Giovana Piva; Antunes, Marina Venzon; Carrer, Caroline; Valandro, Eduarda Trevizani; Santos, Sílvia; Glaeser, Jéssica; Mattos, Larissa; da Silva, Luciano Basso; Linden, Rafael

    2016-01-01

    The evaluation of formaldehyde (FD) exposure in beauty salons, due to the use of hair straightening products, and its relation with genotoxicity biomarkers was performed in this study. Regardless of official recommendations, the inappropriate use of homemade hair creams has became a popular practice in Brazil, and high formaldehyde content in the "progressive straightening" creams can contain mutagens that could increase the incidence of neoplasia in those people who use them. Damage to DNA was assessed by conducting a micronuclei test (MNT) on buccal cells and the comet assay on heparinized venous blood samples. A total of 50 volunteers were recruited at six different beauty salons (labeled A to F). At two salons that used products that did not contain FD (salons D and E), environmental FD concentrations were 0.04 and 0.02 ppm. In contrast, the products used at salons A, B, C, and F contained 5.7, 2.61, 5.9, and 5.79% of FD, and these salons had environmental FD concentrations of 0.07, 0.14, 0.16, and 0.14 ppm, respectively. Comparison of the beauty salon workers from each of the six beauty salons revealed significant differences in urinary formic acid (FA) concentration before exposure (p = 0.016), urinary FA after exposure (p = 0.004), variation in FA concentration before and after exposure (p = 0.018), environmental FD concentration (p < 0.001), cytogenetic damage detected by the comet assay according to both damage index (p < 0.001) and frequency of damage (p < 0.001), and for karyorrhexis only according to the MNT (p = 0.001). PMID:26351198

  5. Novel analytical method to measure formaldehyde release from heated hair straightening cosmetic products: Impact on risk assessment.

    PubMed

    Galli, Corrado Lodovico; Bettin, Federico; Metra, Pierre; Fidente, Paola; De Dominicis, Emiliano; Marinovich, Marina

    2015-08-01

    Hair straightening cosmetic products may contain formaldehyde (FA). In Europe, FA is permitted for use in personal care products at concentrations ⩽ 0.2g/100g. According to the Cosmetic Ingredient Review (CIR) Expert Panel products are safe when formalin (a 37% saturated solution of FA in water) concentration does not exceed 0.2g/100g (0.074 g/100g calculated as FA). The official method of reference does not discriminate between "free" FA and FA released into the air after heating FA donors. The method presented here captures and collects the FA released into the air from heated cosmetic products by derivatization with 2,4-dinitrophenylhydrazine and final analysis by UPLC/DAD instrument. Reliable data in terms of linearity, recovery, repeatability and sensitivity are obtained. On a total of 72 market cosmetic products analyzed, 42% showed FA concentrations very close to or above the threshold value (0.074 g/100g calculated as FA) suggested by the Cosmetic Ingredient Review committee, whereas 11 products, negative using the official method of reference, were close to or above the threshold value (0.074 g/100g calculated as FA). This may pose a health problem for occasional users and professional hair stylists. PMID:26003512

  6. Numerical modeling of gravel bed river response to meander straightening: The coupling between the evolution of bed pavement and long profile

    NASA Astrophysics Data System (ADS)

    Talbot, Tracey; Lapointe, Michel

    2002-06-01

    Artificial meander straightening (rectification) was conducted in the early 1960s along the Sainte-Marguerite River, Canada, in order to facilitate highway construction along the valley. Previous studies [Talbot and Lapointe, 2002] confirm that vertical reprofiling, coupled with pavement coarsening in the degrading reach, were the main responses counteracting the disequilibrium in gravel transport rates triggered at rectification of this system. Numerical simulations, using SEDROUT2.0, a one-dimensional hydraulic and sediment transport model, and validated against the observed channel response, show the important role played by an advancing wave of pavement coarsening down the rectified reach in modulating the bed degradation response. Simulations extending into the future reveal an asymptotically slowing approach to equilibrium in the middle of the 21st century, with a response half-time of the order of 10 years. In near-threshold gravel bed systems like the Sainte-Marguerite River, pavement coarsening after rectification buffers the system against extreme degradation. Most significantly for watershed management, this also appears to severely limit the extent of propagation of degradation upstream of the rectification.

  7. Subsurface Characterization of Mystic Lake Paleoseismic site on the Claremont Fault Using CPT Data: Evidence for Straightening of the northern San Jacinto Fault, California

    NASA Astrophysics Data System (ADS)

    Marliyani, G. I.; Rockwell, T. K.; Onderdonk, N.; McGill, S. F.

    2010-12-01

    We collected Cone Penetrometer Test (CPT) data along two transects across a small releasing step over at the Mystic Lake paleoseismic site along the Claremont segment of San Jacinto Fault, California. The primary reasons for this study are to characterize the Holocene pattern of sedimentation and to locate the most promising areas for additional trenching. At the depth of the trench, CPT data agree well with trench observations to better than 10cm resolution. The main fault identified in our 2009 trench is clearly the principal dip slip fault at depth, and shows increasing vertical separation with increasing depth. Based on limited shallow age data from the trench, the sedimentation rate varies by a factor of two across the main fault, making this an ideal paleoseismic site. The late Holocene sedimentation rate is 3-4 mm/yr within the small sag depression, with units at 2 m depth west of the fault appearing at 4-6 m depth east of the fault in the sag. As we only trenched to about 2 m depth, the current paleoseismic record of pre-historical events is probably a minimum. The young active fault is about 0.5 km from the basin bounding mapped trace of the Claremont fault, which displays minimal Holocene activity in our preliminary trenches. Along with the presence of young faults within the Mystic Lake step over between the Casa Loma and Claremont strands (also referred to as the Hemet step-over), as determined from seismic reflection and seismicity data, these observations suggest that the northern San Jacinto fault is reorganizing and straightening, and will eventually bypass this large releasing step in San Jacinto Valley, thereby lengthening the straight continuous section of San Jacinto Fault. Rupture of the entire Clark-Casa Loma-Claremont fault zone could result in earthquakes as large as Mw7.6, rivaling the San Andreas fault for hazard to the densely populated Los Angeles and San Bernardino/Riverside areas.

  8. STRAIGHTENING THE DENSITY-DISPLACEMENT RELATION WITH A LOGARITHMIC TRANSFORM

    SciTech Connect

    Falck, Bridget L.; Neyrinck, Mark C.; Aragon-Calvo, Miguel A.; Lavaux, Guilhem; Szalay, Alexander S.

    2012-01-20

    We investigate the use of a logarithmic density variable in estimating the Lagrangian displacement field motivated by the success of a logarithmic transformation in restoring information to the matter power spectrum. The logarithmic relation is an extension of the linear relation, motivated by the continuity equation, in which the density field is assumed to be proportional to the divergence of the displacement field; we compare the linear and logarithmic relations by measuring both of these fields directly in a cosmological N-body simulation. The relative success of the logarithmic and linear relations depends on the scale at which the density field is smoothed. Thus we explore several ways of measuring the density field, including Cloud-In-Cell smoothing, adaptive smoothing, and the (scale-independent) Delaunay tessellation, and we use both a Fourier-space and a geometrical tessellation approach to measuring the divergence. We find that the relation between the divergence of the displacement field and the density is significantly tighter and straighter with a logarithmic density variable, especially at low redshifts and for very small ({approx}2 h{sup -1} Mpc) smoothing scales. We find that the grid-based methods are more reliable than the tessellation-based method of calculating both the density and the divergence fields, though in both cases the logarithmic relation works better in the appropriate regime, which corresponds to nonlinear scales for the grid-based methods and low densities for the tessellation-based method.

  9. Characterization of formaldehyde exposure resulting from the use of four professional hair straightening products.

    PubMed

    Pierce, J S; Abelmann, A; Spicer, L J; Adams, R E; Glynn, M E; Neier, K; Finley, B L; Gaffney, S H

    2011-11-01

    An exposure simulation study was conducted to characterize potential formaldehyde exposures of salon workers and clients during keratin hair smoothing treatments. Four different hair treatment brands (Brazilian Blowout, Coppola, Global Keratin, and La Brasiliana) were applied to separate human hair wigs mounted on mannequin heads. Short-term (6-16 min) and long-term (41-371 min) personal and area samples (at distances of 0.5 to 3.0 m from the source) were collected during each treatment for the 1-day simulation. A total of 88 personal, area, and clearance samples were collected. Results were analyzed based on task sampling (blow-dry, flat-iron), treatment sampling (per hair product), and time-weighted averages (per hair treatment, four consecutive treatments). Real-time monitoring of tracer gas levels, for determining the air exchange rate, and formaldehyde levels were logged throughout the simulation. Bulk samples of each hair treatment were collected to identify and quantify formaldehyde and other chemical components that may degrade to formaldehyde under excessive heat. Mean airborne concentrations of formaldehyde ranged from 0.08-3.47 ppm during blow-dry and 0.08-1.05 ppm during flat-iron. During each treatment, the mean airborne concentrations ranged from 0.02-1.19 ppm throughout different zones of the salon. Estimated 8-hr time-weighted averages for one treatment per day ranged from 0.02 ppm for La Brasiliana to 0.08-0.16 ppm for Brazilian Blowout. For four treatments per day, means ranged from 0.04-0.05 ppm for La Brasiliana to 0.44-0.75 ppm for Brazilian Blowout. Using all four products in one day resulted in estimated 8-hr time-weighted averages ranging from 0.17-0.29 ppm. Results from bulk sampling reported formaldehyde concentrations of 11.5% in Brazilian Blowout, 8.3% in Global Keratin, 3% in Coppola, and 0% in La Brasiliana. Other products that degrade into formaldehyde were detected in Global Keratin, Coppola, and La Brasiliana. The results of this study show that professional hair smoothing treatments--even those labeled "formaldehyde-free"--have the potential to produce formaldehyde concentrations that meet or exceed current occupational exposure limits. PMID:22035353

  10. Let's Get This Straightened Out: Finding a Place and Presence for Sexual/Gender Identity-Difference in Peace Education

    ERIC Educational Resources Information Center

    Mizzi, Robert

    2010-01-01

    Expressions of homo/transphobia continue to rupture and sometimes even erase the lives of persons with sexual/gender identity-difference across the globe. Despite this, experiences with violence of this nature largely go unexamined in peace education scholarship. In order to begin a discussion about sexuality/gender identity-difference within a…

  11. Straighten the Back to Sit: Belly-Cultivation Techniques as "Modern Health Methods" in Japan, 1900-1945.

    PubMed

    Wu, Yu-Chuan

    2016-09-01

    In Japan, the first half of the twentieth century saw a remarkable revival of concern with the cultivation of the belly, with a variety of belly-cultivation techniques, particularly breathing exercise and meditative sitting, widely practiced for improving health and treating diseases. This article carefully examines some practitioners' experiences of belly-cultivation practice in attempting to understand its healing effects for them within their life histories and contemporary intellectual, social and cultural contexts. It shows that belly-cultivation practice served as a medium for some practitioners to reflect on and retell their life stories, and that the personal charisma of certain masters and the communities developing around them provided practitioners with a valuable sense of belonging in an increasingly industrialized and urbanized society. Moreover, these belly-cultivation techniques provided an embodied way for some to explore and affirm their sense of self and develop individual identity. While they were increasingly promoted as cultural traditions capable of cultivating national character, they also served as healing practices by inspiring practitioners with a sense of collective identity and purpose. With these analyses, this article sheds light on the complicated meanings of belly-cultivation for practitioners, and provides illustrative examples of the multitude of meanings of the body, bodily cultivation and healing. PMID:26848985

  12. Cold Saw Operator (iron & steel) 6-88.651; Cold Sizing Mill Operator (iron & steel) 4-88.315; Decambering Mill Operator (iron & steel) 6-88.346; Flying Cut-Off Machine Operator (iron & steel) 6-88.655; Rotary Straightener Operator (iron & steel) 6-88.346; Straightener Machine Operator (iron & steel) 6-88.354; Tube Straightener Operator (iron & steel) 6-88.346; Welder (iron & steel) 4-88.343; Welder, Assistant (iron & steel) 4-88.344--Technical

    ERIC Educational Resources Information Center

    Manpower Administration (DOL), Washington, DC. U.S. Training and Employment Service.

    The United States Training and Employment Service General Aptitude Test Battery (GATB), first published in 1947, has been included in a continuing program of research to validate the tests against success in many different occupations. The GATB consists of 12 tests which measure nine aptitudes: General Learning Ability; Verbal Aptitude; Numerical…

  13. Straightening of the northern San Jacinto Fault, California as seen in the fault structure evolution of the San Jacinto step-over

    NASA Astrophysics Data System (ADS)

    Marliyani, G. I.; Rockwell, T. K.; Onderdonk, N.; McGill, S. F.

    2011-12-01

    We investigate a releasing step-over between the Casa Loma and Claremont strands of the northern San Jacinto fault zone to evaluate the Late Quaternary structural evolution of the fault zone, and to assess the likelihood of a rupture jumping across the step-over. Our new CPT and trench observations along the Claremont fault at Mystic Lake indicate that the main strand of the Claremont fault has jumped nearly a half kilometer westward into the San Jacinto releasing step-over during the late Quaternary. Multiple faults are inferred from the CPT data within a small sag at the NE side of the step-over that cuts through younger stratigraphy to the west of the basin bounding fault near Mystic Lake. Previous seismic reflection data also suggest the presence of a young fault that cuts basin strata beneath the middle of Mystic Lake farther west from our study area, and seismicity observations are consistent with the hypothesis that new fault strands have formed within the step-over zone. Numerous tectono-geomorphic features observed in satellite and LiDAR DEM imagery are interpreted to delineate the location of the currently active faults, as well as a zone of faults that cut across the basin from the northern end of the Casa Loma fault to the southern end of the active trace of the Claremont fault. Finally, new paleoseismic data from Mystic Lake site suggest that some late Holocene earthquakes may have jumped the step-over. All of these observations suggest that the San Jacinto step-over, which has been used as the primary basis for segmenting the northern San Jacinto fault zone, is being by-passed and that the fault zone may now be capable of larger earthquakes than previously expected.

  14. Collagenase Clostridium Histolyticum Injection

    MedlinePlus

    ... make it difficult to straighten one or more fingers) when a cord of tissue can be felt ... the cord of thickened tissue and allows the finger(s) to be straightened. In people with Peyronie's disease, ...

  15. Mallet finger - aftercare

    MedlinePlus

    Baseball finger - aftercare; Drop finger - aftercare; Avulsion fracture - mallet finger - aftercare ... Mallet finger occurs when you cannot straighten your finger: when you try to straighten it, the tip of your ...

  16. Orthodontics and Aligners

    MedlinePlus

    ... Repairing Chipped Teeth Teeth Whitening Tooth-Colored Fillings Orthodontics and Aligners Straighten teeth for a healthier smile. Orthodontics When consumers think about orthodontics, braces are the ...

  17. The crooked nose.

    PubMed

    Shipchandler, Taha Z; Papel, Ira D

    2011-04-01

    Straightening a crooked nose is a challenge. Several techniques exist ranging from simple to technically complex. It is important to approach the nose systematically and to remember that perfection may be impossible to achieve. If straightening is not attainable, softening grafts or onlay grafts should be used to camouflage subtle irregularities. PMID:21404162

  18. Osteotomies in the crooked nose.

    PubMed

    Bloom, Jason D; Immerman, Sara B; Constantinides, Minas

    2011-10-01

    The crooked nasal pyramid and upper third of the nose can be straightened with various osteotomes. Appropriate solutions to maximize successful nasal straightening require a thorough knowledge of the anatomy, a comprehensive preoperative plan, and the appropriate osteotomy choice. PMID:22028010

  19. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Benkowski, Robert J. (Inventor); Kiris, Cetin (Inventor); Kwak, Dochan (Inventor); Rosenbaum, Bernard J. (Inventor); Bacak, James W. (Inventor); DeBakey, Michael E. (Inventor)

    1999-01-01

    A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.

  20. Effect of channel plane form on formation process of Sandbars

    NASA Astrophysics Data System (ADS)

    Takahashi, Gen; Yasuda, Hiroyasu

    Almost no explanation is given about development process of sand bar in non-straighten channel because the phenomenon of sand bar has been investigated using straighten channel. This study conducted a numerical experiment of development process of sand bar in a meandering channel and a figure-of-eight(gourd) as fixed wall. The results shows that the development process clearly differs in channel of straighten, meandering and figure-of-eight(gourd). The result of figure-of-eight(gourd) doesn't occur mode degradation and keep multiple bars.

  1. Treatment of the scoliotic nose with extracorporeal septoplasty.

    PubMed

    Gubisch, Wolfgang

    2015-02-01

    A septal deformity with severe deviation of the septal L strut is seen in nearly every crooked or scoliotic nose. Unless the underlying septal deformity is properly diagnosed and treated, the nasal axis cannot be completely straightened. In addition, because standard septoplasty techniques often fail to adequately address severe L-strut deformities, extracorporeal septoplasty is often a prerequisite for straightening the crooked nose. This article presents a detailed explanation of the extracorporeal technique, as well as representative long-term clinical results showing the efficacy and durability of extracorporeal septoplasty. Extracorporeal septoplasty a safe and reliable method for straightening the severely deviated nose. PMID:25430926

  2. Precise Restraightening of Bent Studs

    NASA Technical Reports Server (NTRS)

    Boardman, R. E.

    1982-01-01

    Special tool quickly bends studs back into shape accurately and safely by force applied by hydraulic ram, with deflection being measured by dial indicator. Ram and indicator can be interchanged for straightening in reverse direction.

  3. Femoral nerve damage (image)

    MedlinePlus

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  4. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The...

  5. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The...

  6. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The...

  7. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The...

  8. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The...

  9. Cosmetic Dentistry

    MedlinePlus

    If you have stained, broken or uneven teeth, cosmetic dentistry can help. Cosmetic dentistry is different from orthodontic treatment, which can straighten your teeth with braces or other devices. Cosmetic dental ...

  10. 15. VIEW LOOKING SOUTHWEST INSIDE OF THE 22' BAR MILL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW LOOKING SOUTHWEST INSIDE OF THE 22' BAR MILL SHIPPING BUILDING No. 1 AT THE 10' SUTTON BAR STRAIGHTENER. - U.S. Steel Duquesne Works, 22-Inch Bar Mill, Along Monongahela River, Duquesne, Allegheny County, PA

  11. Hair Treatments and Pregnancy

    MedlinePlus

    ... is likely that only a small amount of hair straightening products are actually absorbed into your system, so the developing baby would only be exposed to small amounts. I work full time as a cosmetologist and recently became ...

  12. What Is Scoliosis?

    MedlinePlus

    ... causes of idiopathic scoliosis. They have studied genetics, growth, and changes in the spine, muscles, and nerves. They are studying how different treatments can help to straighten the spine or keep curves from getting worse. They are also studying the ...

  13. Stream Channelization: Conflict Between Ditchers, Conservationists

    ERIC Educational Resources Information Center

    Gillette, Robert

    1972-01-01

    Summarizes the argument between the advocates of stream straightening for flood control, drainage, and navigation, and those concerned with the maintenance of ecological communities and the aesthetic values of natural" streams. (AL)

  14. Cosmetic Dentistry

    MedlinePlus

    If you have stained, broken or uneven teeth, cosmetic dentistry can help. Cosmetic dentistry is different from orthodontic treatment, which can straighten your teeth with braces or other devices. Cosmetic dental procedures include Bleaching to make teeth whiter ...

  15. Waardenburg syndrome

    MedlinePlus

    ... heterochromia ) Pale color skin, hair, and eyes (partial albinism) Difficulty completely straightening joints Possible slight decrease in ... ncbi.nlm.nih.gov/pubmed/20301703 . Read More Albinism Autosomal dominant Hearing loss Update Date 8/1/ ...

  16. Metatarsus adductus

    MedlinePlus

    ... may be needed if the foot is very flexible and easy to straighten or move in the ... not improve or your child's foot is not flexible enough, other treatments will be tried: Stretching exercises ...

  17. Collagenase Clostridium Histolyticum Injection

    MedlinePlus

    ... disease (a thickening of tissue [plaque] inside the penis that causes the penis to curve). Collagenase Clostridium histolyticum injection is in ... the plaque of thickened tissue and allows the penis to be straightened.

  18. Irritant contact dermatitis complicated by deep-seated staphylococcal infection caused by a hair relaxer.

    PubMed

    Kaur, Birinder J; Singh, Harmeet; Lin-Greenberg, Alan

    2002-02-01

    Chemical hair relaxers are used by many women to straighten their hair. We describe a case of a deep soft tissue staphylococcal abscess that complicated an irritant contact dermatitis from a hair relaxer treatment. PMID:11853045

  19. Irritant contact dermatitis complicated by deep-seated staphylococcal infection caused by a hair relaxer.

    PubMed Central

    Kaur, Birinder J.; Singh, Harmeet; Lin-Greenberg, Alan

    2002-01-01

    Chemical hair relaxers are used by many women to straighten their hair. We describe a case of a deep soft tissue staphylococcal abscess that complicated an irritant contact dermatitis from a hair relaxer treatment. PMID:11853045

  20. Braces

    MedlinePlus

    ... that straightens your teeth faster and easier. The rubber bands that go along with braces come in ... kids just need regular braces with wires and rubber bands doing their jobs to keep pressure on ...

  1. Macroinvertebrate response to stream restoration by large wood addition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel incision processes resulting primarily from channel straightening/dredging and watershed deforestation have been among the most profound degradations in our streams. Physical changes to streams affected by channel incision processes have included significant increases in streambed degradatio...

  2. Autotropism, automorphogenesis, and gravity

    NASA Technical Reports Server (NTRS)

    Stankovic, B.; Volkmann, D.; Sack, F. D.

    1998-01-01

    Segments of organs that have undergone gravitropic curvature later straighten during the course of gravitropism or after the g-vector becomes randomized on a clinostat. Little is known about the mechanism underlying these and perhaps related phenomena which have been described with various overlapping terms such as autotropism, autotropic straightening, automorphosis, automorphogenesis, automorphic curvature, and gravitropic straightening. The types of phenomena that historically have been named by the above terms are reviewed critically with respect to an interaction with gravitropism. We suggest that the term "autotropism" should not be applied to the phenomenon of organ straightening that occurs during the course of gravitropism, since this straightening is part of a complex series of local growth adjustments overall through time, and since this phenomenon is not itself a tropistic response to a directional exogenous stimulus. It is suggested that the term autotropism should be used only for the phenomenon of organ straightening that occurs after the g-vector is randomized on a clinostat or withdrawn in the microgravity conditions of spaceflight. Usage of the term automorphogenesis is most appropriate for describing curvatures or orientations that result from morphological relationships such as in nastic curvatures.

  3. Kinetics for phototropic curvature by etiolated seedlings of Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Orbovic, V.; Poff, K. L.

    1991-01-01

    An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 16 degrees about 80 minutes after stimulation. The seedlings then curved upward again or straightened by about 6 degrees during the subsequent 100 minutes. Seedlings rotated on a clinostat reached a similar maximum curvature following photostimulation. These seedlings maintained that curvature for 30 to 40 minutes before subsequently straightening to the same extent as the stationary seedlings. It is concluded that straightening is not a consequence of gravitropism, although gravity has some effect on the phototropism kinetics.

  4. Developing processing techniques for Skylab data

    NASA Technical Reports Server (NTRS)

    Nalepka, R. F. (Principal Investigator); Malila, W. A.; Morgenstern, J. P.

    1975-01-01

    The author has identified the following significant results. The effects of misregistration and the scan-line-straightening algorithm on multispectral data were found to be: (1) there is greatly increased misregistration in scan-line-straightening data over conic data; (2) scanner caused misregistration between any pairs of channels may not be corrected for in scan-line-straightened data; and (3) this data will have few pure field center pixels than will conic data. A program SIMSIG was developed implementing the signature simulation model. Data processing stages of the experiment were carried out, and an analysis was made of the effects of spatial misregistration on field center classification accuracy. Fifteen signatures originally used for classifying the data were analyzed, showing the following breakdown: corn (4 signatures), trees (2), brush (1), grasses, weeds, etc. (5), bare soil (1), soybeans (1), and alfalfa (1).

  5. Kinetics for Phototropic Curvature by Etiolated Seedlings of Arabidopsis thaliana 1

    PubMed Central

    Orbović, Vladimir; Poff, Kenneth L.

    1991-01-01

    An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 16° about 80 minutes after stimulation. The seedlings then curved upward again or straightened by about 6° during the subsequent 100 minutes. Seedlings rotated on a clinostat reached a similar maximum curvature following photostimulation. These seedlings maintained that curvature for 30 to 40 minutes before subsequently straightening to the same extent as the stationary seedlings. It is concluded that straightening is not a consequence of gravitropism, although gravity has some effect on the phototropism kinetics. PMID:11538373

  6. Laser Welding of Large Scale Stainless Steel Aircraft Structures

    NASA Astrophysics Data System (ADS)

    Reitemeyer, D.; Schultz, V.; Syassen, F.; Seefeld, T.; Vollertsen, F.

    In this paper a welding process for large scale stainless steel structures is presented. The process was developed according to the requirements of an aircraft application. Therefore, stringers are welded on a skin sheet in a t-joint configuration. The 0.6 mm thickness parts are welded with a thin disc laser, seam length up to 1920 mm are demonstrated. The welding process causes angular distortions of the skin sheet which are compensated by a subsequent laser straightening process. Based on a model straightening process parameters matching the induced welding distortion are predicted. The process combination is successfully applied to stringer stiffened specimens.

  7. A Novel Representation for Riemannian Analysis of Elastic Curves in ℝn

    PubMed Central

    Joshi, Shantanu H.; Klassen, Eric; Srivastava, Anuj; Jermyn, Ian

    2011-01-01

    We propose a novel representation of continuous, closed curves in ℝn that is quite efficient for analyzing their shapes. We combine the strengths of two important ideas - elastic shape metric and path-straightening methods -in shape analysis and present a fast algorithm for finding geodesics in shape spaces. The elastic metric allows for optimal matching of features while path-straightening provides geodesics between curves. Efficiency results from the fact that the elastic metric becomes the simple 2 metric in the proposed representation. We present step-by-step algorithms for computing geodesics in this framework, and demonstrate them with 2-D as well as 3-D examples. PMID:21311729

  8. Tennis Rackets and the Parallel Axis Theorem

    NASA Astrophysics Data System (ADS)

    Christie, Derek

    2014-04-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  9. Oversight of the Indian Child Welfare Act. Hearing before the Select Committee on Indian Affairs, United States Senate, Ninety-Sixth Congress, Second Session on Oversight of the Indian Child Welfare Act (Public Law 95-608).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Select Committee on Indian Affairs.

    The Select Committee on Indian Affairs met on June 30, 1980, for an oversight hearing on the Indian Child Welfare Act of 1978 to correct flaws and straighten out problems concerning Public Law 95-608 and the way it is implemented. Various members of the administration and a group of Indian leaders from across the country attended the hearing, at…

  10. Flaunting It for Social Justice

    ERIC Educational Resources Information Center

    Jackson, Janna

    2010-01-01

    By examining various movements in education in "Flaunt It! Queers Organizing for Public Education and Justice," Quinn and Meiners show a systematic and intentional "straightening" of American public schools. Throughout the book, the authors explore how various public and private realms operate to try to silence queer voices, and they discuss ways…

  11. Nanostructure devices and fabrication method

    NASA Technical Reports Server (NTRS)

    Stevens, Ramsey M. (Inventor)

    2009-01-01

    An ion flux is directed to a carbon nanotube to permanently shape, straighten and/or bend the carbon nanotube into a desired configuration. Such carbon nanotubes have many properties that make them ideal as probes for Scanning Probe Microscopy and many other applications.

  12. 40 CFR 63.5385 - How do I measure the quantity of finish applied to the leather?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) of this section: (i) Locate the flow sensor and other necessary equipment such as straightening vanes in or as close to a position that provides a representative flow. (ii) Use a flow sensor with a... distributions due to upstream and downstream disturbances. (iv) Conduct a flow sensor calibration check at...

  13. 40 CFR 63.1452 - What are my monitoring requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... exempted from the requirements of this paragraph (a). (1) Install the monitoring device, associated sensor(s), and recording equipment according to the manufacturers' specifications. Locate the sensor(s... flow sensor and other necessary equipment such as straightening vanes in a position that provides...

  14. Cyclical fluvial response caused by rechannelization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Yalobusha River system in northwestern Mississippi was channelized ca. 1967 to enhance channel capacity and alleviate flooding. Design of the channelization project allowed the enlarged, straightened channel to discharge into an unmodified sinuous reach, and the junction between these two geomet...

  15. Taking Care of Your Hair

    MedlinePlus

    ... chemical treatments: Relaxers. Relaxers (straighteners) work by breaking chemical bonds in curly hair. Relaxers containing lye can cause skin irritation and hair breakage. Although "no lye" relaxers may cause less ... before a chemical relaxing treatment can increase these risks. And don' ...

  16. Hair--Curvy or Straight; Cosmetology 1: 9205.04.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    Permanent curling and straightening require a thorough understanding of hair. Through diligent study and practice the student prepares for a profitable part of a beauty career. The course requires 135 hours of classroom-laboratory instruction. Those entering must have mastered the skills of shaping and conditioning hair. On completion of the…

  17. Tennis Rackets and the Parallel Axis Theorem

    ERIC Educational Resources Information Center

    Christie, Derek

    2014-01-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  18. View north of inside machine shop 36; shop floor accommodates ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View north of inside machine shop 36; shop floor accommodates lathes capable of machining a cylinder 60 inches in diameter and 75 feet long; other equipment includes horizontal and vertical jig borders, hydraulic tube straighteners and other equipment for precision machining of large ship components. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  19. 40 CFR 63.1452 - What are my monitoring requirements?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... exempted from the requirements of this paragraph (a). (1) Install the monitoring device, associated sensor(s), and recording equipment according to the manufacturers' specifications. Locate the sensor(s... flow sensor and other necessary equipment such as straightening vanes in a position that provides...

  20. Influence of Physical Habitat and Agricultural Contaminants on Fishes within Agricultural Drainage Ditches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural drainage ditches are used within agricultural watersheds for the removal of excess water from agricultural fields. These headwater streams have been constructed or modified so they possess an enlarged trapezoidal cross-section, straightened channels, and riparian zones lacking woody veg...

  1. Surgery for Peyronie's disease

    PubMed Central

    Levine, Laurence A; Larsen, Stephen M

    2013-01-01

    Peyronie's disease (PD) is most simply referred to as a fibrotic wound-healing disorder of the tunica albuginea. It is both a physically and psychologically devastating disorder that causes penile deformity, curvature, hinging, narrowing and shortening, which may compromise sexual function. Although a variety of non-surgical treatments have been suggested, none to date offer a reliable and effective correction of the penile deformity. As a result, surgery remains the gold standard treatment option, offering the most rapid and reliable treatment which will be the focus of this article. We review the preoperative evaluation, surgical algorithm, graft materials and postoperative management of PD. Outcomes for tunical shortening, tunical lengthening and penile prosthesis placement for penile straightening are reviewed. Tunica albuginea plication is the preferred method of straightening for men with adequate rigidity and less severe disease defined as curvature less than 70° without narrowing/hinging. Men who have more severe, complex deformity, but maintain strong preoperative erectile function should be considered candidates for straightening with plaque incision or partial excision and grafting. Finally, for those men who have inadequate rigidity and PD, penile prosthesis placement with straightening is the best approach to address both problems. PMID:23178395

  2. Trigger Finger

    MedlinePlus

    ... it difficult to straighten the finger. Reproduced and adapted from Griffin LY (ed): Essentials of Musculoskeletal Care. ... surgery, the tendon sheath is cut. Reproduced and adapted from Griffin LY (ed): Essentials of Musculo- skeletal ...

  3. Speakeasy: A Text for Speaking, Volume 2. English for Special Purposes Series: Autobody Repair.

    ERIC Educational Resources Information Center

    Peet, William, Jr.

    This is the second of two volumes devoted to dialogs designed for classroom use by students of English as a second language. Survival skills are emphasized. The dialogs are grouped under the following titles: (1) "Buying Furniture," (2) "Straightening Metal Surfaces," (3) "Opening a Checking Account," (4) "Going to the Doctor," (5) "Building…

  4. Andy Wants to Be Grown Up: Managing Parental Anxiety.

    ERIC Educational Resources Information Center

    Hamilton, Jennifer

    1980-01-01

    The mother of a moderately retarded 11-year-old boy describes her reactions to having her son's teeth straightened. The author realized that the anxiety she felt about the orthodontic procedure was not so much concern for her son as her own fear of dental work. (PHR)

  5. 7 CFR 201.56-7 - Lily family, Liliaceae.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... growing point, provided other essential structures are normal. (v) Root system: A long slender primary... emerges with the seed coat and endosperm attached to the tip. A sharp bend known as the “knee” forms... cotyledon tip is pulled from the soil and straightens except for a slight kink which remains at the site...

  6. 7 CFR 201.56-7 - Lily family, Liliaceae.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... growing point, provided other essential structures are normal. (v) Root system: A long slender primary... emerges with the seed coat and endosperm attached to the tip. A sharp bend known as the “knee” forms... cotyledon tip is pulled from the soil and straightens except for a slight kink which remains at the site...

  7. Bilingual Skills Training Program. Auto Body Repair. Module 3.0: Basic Metal Repair.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on basic metal repair is the third of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students to…

  8. Bilingual Vocational Training Program. Auto Body Repair. Module 4.0: Auto Body Welding.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on auto body welding is the fourth of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students to…

  9. Barber/Cosmetologist Curriculum. Program Information.

    ERIC Educational Resources Information Center

    Moraine Park Technical Coll., Fond du Lac, WI.

    This guide provides the instructor with materials for a barber/cosmetologist program. Seventeen study guides are provided: anatomy and physiology; applied chemistry; chemical straightening/relaxing; chemical waving; electricity and light therapy; facial services; hair coloring and lightening (bleach); hair cutting; hair, skin, and nail disorders;…

  10. Bilingual Vocational Training Program. Auto Body Repair. Module 1.0: Beginning Auto Body.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on beginning auto body is the first of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students…

  11. 40 CFR 63.1452 - What are my monitoring requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... device, associated sensor(s), and recording equipment according to the manufacturers' specifications. Locate the sensor(s) used for monitoring in or as close to a position that provides a representative... section. (i) Locate the flow sensor and other necessary equipment such as straightening vanes in...

  12. Scanning Electron Microscopy Study of Hair Shaft Damage Secondary to Cosmetic Treatments of the Hair

    PubMed Central

    Kaliyadan, Feroze; Gosai, BB; Al Melhim, Walid Naief; Feroze, Kaberi; Qureshi, Habib Ahmad; Ibrahim, Sayed; Kuruvilla, Joel

    2016-01-01

    Introduction and Background: Cosmetic procedures for hair, such as bleaching, dyeing, and straightening, are commonly used around the world. It has been suggested that excessive use of such procedures can cause damage to the hair shaft. We aimed to assess hair shaft changes using scanning electron microscopy (SEM) in female volunteers who frequently use hair treatment procedures such as bleaching, dyeing, or straightening. Methods: A cross-sectional, controlled study in a sample of 25 female volunteers (19 study group and 6 controls) in the age group of 18–45 years. The study group was composed of volunteers who regularly used different cosmetic hair treatment procedures such as bleaching, dyeing, and straightening (any one of these or a combination). The control group had never used any specific hair treatment procedure. The hair shaft damage as seen on SEM was assessed using a standardized scoring system and compared among the two groups statistically. The hair shafts were also examined clinically and with light microscopy. Results: No significant differences were seen between the test and control groups with regard to normal clinical examination and light microscopy findings. A higher degree of hair shaft damage was evident under SEM in the study group as compared to the control group. This difference was statistically significant. Conclusions: Regular use of procedures such as bleaching, dyeing, or straightening can lead to subtle changes in the hair shaft which can be detected early by SEM. PMID:27601867

  13. 49 CFR 572.85 - Lumbar spine flexure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rotate from its initial position in accordance with Figure No. 18 of § 572.21 (49 CFR part 572) by 40 degrees at a force level of not less than 18 pounds and not more than 22 pounds, and straighten upon... Lumbar spine flexure. (a) When subjected to continuously applied force in accordance with paragraph...

  14. 49 CFR 173.28 - Reuse, reconditioning and remanufacture of packagings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Editorial Note: For Federal Register citations affecting § 173.28, see the List of CFR Sections Affected...) straightened and sealed, and all non-integral gaskets replaced: and (iii) Inspecting after cleaning but before...-integral gaskets and closure devices with new or refurbished parts, and cushioning and cushioning...

  15. Crouzon Syndrome (Craniofacial Dysostosis)

    MedlinePlus

    ... between the upper and lower jaws). Dental and plastic surgery specialists monitor facial growth and correct deformities. The ... normally. Orthodontics, to straighten the teeth, and jaw surgery, to place the ... in childhood, the teens or even the adult years. These are complicated ...

  16. Bilingual Vocational Training Program. Auto Body Repair. Module 2.0: Tools and Equipment.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on tools and equipment is the second of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students…

  17. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

    PubMed Central

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-01-01

    Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

  18. V-TECS Guide for Auto Body Repair.

    ERIC Educational Resources Information Center

    Gregory, Margaret R.; Benson, Robert T.

    This curriculum guide consists of materials for teaching a course in auto body repair. Addressed in the individual units of the guide are the following topics: the nature and scope of auto body repair; safety; tools; auto body construction; simple metal straightening; welding; painting and refinishing; refinishing complete lacquer; refinishing…

  19. Effects of channelization on fish biomass in river ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel straightening of a meandering river is a common trigger of channel incision which may results in stream bank destabilization. Several of the rivers in the upland portion of the Yazoo River Basin have subjected channelization resulting in changes in the physical and geomorphological charact...

  20. TROPHIC STRUCTURE, REPRODUCTIVE SUCCESS, AND GROWTH RATE OF FISHES IN A NATURAL AND MODIFIED HEADWATER STREAM

    EPA Science Inventory

    The impact of removing riparian vegetation, channel straightening, and fluctuations in flow regime on trophic structure, reproductive success, and growth rate of fishes was assessed in a natural (Jordan Creek(JC)) and modified (Big Ditch(BD)) headwater stream in eastcentral Illin...

  1. Another Vision: THe Church Model of Education Administration (EA).

    ERIC Educational Resources Information Center

    Coleman, Donald G.; And Others

    In 1987 and again in 1988, the National Commission on Excellence in Educational Administration report catalogued a litany of sins committed by educational administration faculties and by institutions of higher education; however, the reports did little to straighten educational administration's crooked halo. Included among the past attempts at…

  2. Gravitropism and phototropism of oat coleoptiles: Post-tropic autostraightening and tissue shrinkage during tropism

    NASA Astrophysics Data System (ADS)

    Tarui, Y.; Iino, M.

    1999-01-01

    We measured changes in length on the two opposite sides of the red-light-grown oat (Avena sativa L.) coleoptiles subjected to either gravitropic or phototropic stimulation and subsequently rotated on a horizontal clinostat. The length measurement was conducted using three 5 mm-long zones delimited by ink markers from the tip. Curvature of each zone was analyzed from the length difference between the two sides. Gravitropism was induced by displacing the seedling from the vertical by 30° or 90° for 25 min. Phototropism was induced by exposing the coleoptile to unilateral blue light for 30 s, which provided a fluence (1.0 μmol m-2) optimal for the pulse-induced positive phototropism or a lower, suboptimal fluence (0.03 μmol m-2). After negatively gravitropic bending, the upper two zones straightened rapidly at either displacement angle. After positively phototropic bending, straightening occurred, but only in the top zone and at the lower fluence. The upper two zones straightened rapidly, however, when bilateral blue light (30 s; 15 μmol m-2 from either direction) was applied 25 min after unilateral stimulation at the higher fluence. Bilateral blue light alone induced no curvature. These results confirm that the straightening of gravitropically bent coleoptiles is autonomic, and suggest that a similar autonomic response participates in the straightening of phototropically bent coleoptiles. Suppression of elongation on the concave side of the coleoptile mainly accounted for gravitropic and phototropic curvatures. The concave side of the top zone shrank during both tropisms. This shrinkage progressed at a high rate from the beginning of curvature response, suggesting that a drop in turgor pressure is the main and direct cause of the shrinkage.

  3. Gravitropism and phototropism of oat coleoptiles: post-tropic autostraightening and tissue shrinkage during tropism.

    PubMed

    Tarui, Y; Iino, M

    1999-01-01

    We measured changes in length on the two opposite sides of the red-light-grown oat (Avena sativa L.) coleoptiles subjected to either gravitropic or phototropic stimulation and subsequently rotated on a horizontal clinostat. The length measurement was conducted using three 5 mm-long zones delimited by ink markers from the tip. Curvature of each zone was analyzed from the length difference between the two sides. Gravitropism was induced by displacing the seedling from the vertical by 30 degrees or 90 degrees for 25 min. Phototropism was induced by exposing the coleoptile to unilateral blue light for 30 s, which provided a fluence (1.0 micromoles m-2) optimal for the pulse-induced positive phototropism or a lower, suboptimal fluence (0.03 micromoles m-2). After negatively gravitropic bending, the upper two zones straightened rapidly at either displacement angle. After positively phototropic bending, straightening occurred, but only in the top zone and at the lower fluence. The upper two zones straightened rapidly, however, when bilateral blue light (30 s; 15 micromoles m-2 from either direction) was applied 25 min after unilateral stimulation at the higher fluence. Bilateral blue light alone induced no curvature. These results confirm that the straightening of gravitropically bent coleoptiles is autonomic, and suggest that a similar autonomic response participates in the straightening of phototropically bent coleoptiles. Suppression of elongation on the concave side of the coleoptile mainly accounted for gravitropic and phototropic curvatures. The concave side of the top zone shrank during both tropisms. This shrinkage progressed at a high rate from the beginning of curvature response, suggesting that a drop in turgor pressure is the main and direct cause of the shrinkage. PMID:11542618

  4. Axial Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  5. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor); Akkerman, James W. (Inventor); Aber, Greg S. (Inventor); Vandamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1993-01-01

    A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  6. Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1996-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  7. ORTHOPEDIC LEG BRACE

    NASA Technical Reports Server (NTRS)

    Myers, William Neil (Inventor)

    2005-01-01

    Knee braces generally have been rigid in both the knee bending direction and in the knee straightening direction unless a manually operated release is incorporated in them to allow the knee to bend. Desirably a braced knee joint should effectively duplicate the compound, complex, actions of a normal knee. The key to knee braces is the knee joint housing. The housing herein carries a number of cam action pawls. with teeth adapted to engage the internal teeth of a ratchet ring mounted in the housing. Cam action return springs and the shape of the cam action pawl teeth allow rotation of the ratchet ring in a leg straightening direction while still supporting a load. The leg can then be extended during walking while at the same time being prevented by the cam action pawls from buckling in the knee bending direction.

  8. Clinical and anthropological perspectives on chemical relaxing of afro-textured hair.

    PubMed

    Aryiku, S A; Salam, A; Dadzie, O E; Jablonski, N G

    2015-09-01

    The culturally engrained practice of 'relaxing' afro-textured hair has been linked with hair and scalp disorders. Herein, we discuss the evolution of human hair types, focusing in particular on afro-textured hair. We explore the biological features of this hair type, and discuss the different methods employed to straighten afro-textured hair, focusing in particular on chemical straightening. We also examine clinical, anthropological, and psychological issues associated with this latter practice. Examples of common scalp pathologies associated with chronic hair relaxing, such as alopecia, hair breakage, caustic burns and irritant contact dermatitis, are also highlighted. The data presented herein should enable clinicians to engage in culturally appropriate discussions with their patients about issues of appearance and conformity. PMID:25764359

  9. Application of CFD to Explain Anomalous Stall Behavior of the SSME Flowmeter

    NASA Technical Reports Server (NTRS)

    Ascoli, E.; Clever, W.; Hadid, A.; Lynch, E. D.; Stewart, M.; Lee, K.

    1999-01-01

    The Space Shuttle Main Engine (SSME) Fuel Flowmeter is located in the duct between the low and high pressure fuel turbopumps. In the flowmeter the rotation rate of a 4-blade rotor positioned downstream of two flow straighteners is employed to measure the engine fuel flow rate and thereby control the engine mixture ratio via the engine controller. Hence, inaccurate operation of the flowmeter could have serious consequences for SSME engine operation and performance, forcing, for example, tanking of extra fuel to allow for inaccurate flowmeter measurement. Since the current flight flowmeter configuration was incorporated into the SSME in the early eighties, some anomalies in flowmeter behavior have been observed. The initial flowmeter incorporated an "egg crate" design for the two flow straighteners which turn the duct flow to make it more uniform and parallel after it has come out of the 90 degree bend just upstream of the flowmeter.

  10. Open-cell Stent Deployment across the Wide Neck of a Large Middle Cerebral Aneurysm Using the Stent Anchor Technique

    PubMed Central

    Shibukawa, Masaaki; Tani, Itaru; Oki, Shuichi; Kurisu, Kaoru

    2016-01-01

    We describe a case of successful open-cell stent deployment across the wide neck of a large middle cerebral artery aneurysm using the stent anchor technique. A microcatheter was looped through the aneurysm and navigated into a distal vessel across the aneurysm neck. Although the loop of the microcatheter in the aneurysm straightened as it was gently withdrawn, the microcatheter again protruded into the aneurysm by open-cell stent navigation. The stent was partially deployed in a vessel distal to the aneurysm neck, withdrawn slowly to straighten the loop of the microcatheter in the aneurysm, and completely deployed across the aneurysm neck. After successful stent deployment, stent-assisted coil embolization was performed without complications. The stent anchor technique was successfully used to deploy an open-cell stent across the aneurysm neck in this case of microcatheter protrusion into the aneurysm during stent navigation. PMID:27114965

  11. Surgery of the nasal septum.

    PubMed

    Mlynski, Gunter

    2006-11-01

    Long-term results after septoplasty are not satisfactory. Apart from a recurrence of deviation, there are various reasons for this: false preoperative analysis, complete straightening of the septum, and a disturbed nasal cycle. Preoperative functional diagnostics with a combination of rhinoresistometry, acoustic rhinometry, and long-term rhinoflowmetry are necessary for differentiating between "physiological" and "pathological" septal deviations and recognizing other causes for obstruction. The surgical procedure of septoplasty includes approach, mobilization, resection, reposition, and finally reconstruction of all three layers. The goal of the operation should not be complete straightening of the nasal septum. The space between the septum and turbinates is of utmost importance. It should not be enlarged as much as possible; rather, it must be shaped in such a way as to allow freely congestion and decongestion reciprocal on the two sides during the nasal cycle. PMID:17131264

  12. Growth Distribution during Phototropism of Arabidopsis thaliana Seedlings.

    PubMed Central

    Orbovic, V.; Poff, K. L.

    1993-01-01

    The elongation rates of two opposite sides of hypocotyls of Arabidopsis thaliana seedlings were measured during phototropism by using an infrared imaging system. In first positive phototropism, second positive phototropism, and red light-enhanced first positive phototropism, curvature toward the light source was the result of an increase in the rate of elongation of the shaded side and a decrease in the rate of elongation of the lighted side of the seedlings. The phase of straightening that followed maximum curvature resulted from a decrease in the elongation rate of the shaded side and an increase in the elongation rate of the lighted side. These data for the three types of blue light-induced phototropism tested in this study and for the phase of straightening are all clearly consistent with the growth rate changes predicted by the Cholodny-Went theory. PMID:12231922

  13. [Peyronie's disease: diagnostics and therapy].

    PubMed

    Hauptmann, A; Diemer, T; Weidner, W

    2011-05-01

    Peyronie's disease is a benign disorder of the penis but the etiology is still unknown. A wound healing disorder after repetitive microtraumatic lesions with inelastic scar formation of the tunica albuginea potentially leads to the typical symptoms of penile plaque formation, penile pain, deviation and erectile dysfunction. A non-surgical therapy based on a clear pathophysiology does not exist although the benefit of several conservative treatment options is under discussion. In the stable stage of the disease patients with Peyronie's disease frequently undergo penile surgery. Depending on the deviation angle, the penile length and the erectile dysfunction different straightening surgery can be performed. This article provides an overview of the natural history of the disease and describes present conservative management strategies and common surgical techniques for penile straightening. PMID:21557048

  14. The aerodynamic performance of several flow control devices for internal flow systems

    NASA Technical Reports Server (NTRS)

    Eckert, W. T.; Wettlaufer, B. M.; Mort, K. W.

    1982-01-01

    An experimental reseach and development program was undertaken to develop and document new flow-control devices for use in the major modifications to the 40 by 80 Foot wind tunnel at Ames Research Center. These devices, which are applicable to other facilities as well, included grid-type and quasi-two-dimensional flow straighteners, louver panels for valving, and turning-vane cascades with net turning angles from 0 deg to 90 deg. The tests were conducted at model scale over a Reynolds number range from 2 x 100,000 to 17 x 100,000, based on chord. The results showed quantitatively the performance benefits of faired, low-blockage, smooth-surface straightener systems, and the advantages of curved turning-vanes with hinge-line gaps sealed and a preferred chord-to-gap ratio between 2.5 and 3.0 for 45 deg or 90 deg turns.

  15. Inward spread of activation in vertebrate muscle fibres

    PubMed Central

    González-Serratos, H.

    1971-01-01

    1. A method for detecting the activation of individual myofibrils or groups of myofibrils within an isolated muscle fibre is described. It consists in making all the myofibrils wavy by setting the fibre in gelatine and compressing it longitudinally; active shortening of myofibrils can then be recognized by the straightening out of the waves. 2. The time course of this straightening during a twitch was found by high-speed ciné micrography. 3. There is a delay of activation between the superficial and central myofibrils, from which the velocity of inward spread of activation can be found. 4. This velocity has a Q10 of 2, and is about 7 cm/sec at 20° C. The mechanism of the inward spread of activation is discussed. 5. On relaxation the waves reappear, showing that there is a spontaneous elongation of the myofibrils. ImagesPlate 1Plate 2Plate 3Plate 4 PMID:5557071

  16. Analysis of data on absorption in the northern part of the milky way

    NASA Technical Reports Server (NTRS)

    Polishchuk, E. P.

    1973-01-01

    The values of absorption for different galactic longitudes are obtained on the basis of star cluster data. It is found that the distance up to the point, where the straightening of the absorption distribution curve begins, depends on the limiting magnitude of the catalogue and the density of absorbing matter near the sun. The picture of absorbing matter distribution in the northern part of the Milky Way is given.

  17. GPOs do some explaining. Concerned about conflicts of interest, a Senate judiciary committee gives GPOs 90 days to create a code of conduct.

    PubMed

    Becker, Cinda

    2002-05-01

    Premier Chairman and CEO Richard Norling and Novation President Mark McKenna feared the worst before a U.S. Senate subcommittee last week. Equipment markers' allegations that their innovative products are barred from the marketplace by deals between GPOs and longtime large suppliers led to the hearing. But instead of lowering the boom, the panel gave the companies a grace period to straighten up. PMID:12037925

  18. Minimally invasive veneers: current state of the art

    PubMed Central

    Vanlıoğlu, Burçin Akoğlu; Kulak-Özkan, Yasemin

    2014-01-01

    Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers. PMID:25506248

  19. Evaluation and Treatment of a Ureterosciatic Hernia Causing Hydronephrosis and Renal Colic

    PubMed Central

    Salari, Keyan; Yura, Emily M.; Harisinghani, Mukesh

    2015-01-01

    Abstract An 87-year-old female presented with complaints of intermittent severe right renal colic. CT imaging demonstrated a ureterosciatic hernia and moderate hydronephrosis proximal to the portion of the ureter that was herniated through the sciatic foramen. A retrograde pyelogram demonstrated a transition point in the ureter at the location of the hernia. A ureteral stent was placed resulting in straightening of the ureter, resolution of hydronephrosis, and complete resolution of the patient's symptoms.

  20. Experimental investigation of inlet flow-control cascades for the NFAC 80- by 120-foot Indraft Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Van Aken, Johannes M.; Scheller, Nina M.

    1988-01-01

    The present investigation of aerodynamic performance for various inlet cascade configurations of an indraft wind tunnel with a short inlet and a low contraction ratio has given attention to the effects of inlet wall shape, antiturbulence screens, and horizontal flow straighteners on test-section flow quality. It is found that an inlet cascade with a tailored vane-splay distribution, antiturbulence screen, and horizontal splitters, will both yield good test section flow quality and furnish isolation from atmospheric winds and turbulence.

  1. Overcoming Robot-Arm Joint Singularities

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Houck, J. A.

    1986-01-01

    Kinematic equations allow arm to pass smoothly through singular region. Report discusses mathematical singularities in equations of robotarm control. Operator commands robot arm to move in direction relative to its own axis system by specifying velocity in that direction. Velocity command then resolved into individual-joint rotational velocities in robot arm to effect motion. However, usual resolved-rate equations become singular when robot arm is straightened.

  2. On quasi-periodic solutions of the 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada equation

    NASA Astrophysics Data System (ADS)

    Cao, Cewen; Wu, Yongtang; Geng, Xianguo

    1999-05-01

    The 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada equation is decomposed into systems of integrable ordinary differential equations resorting to the nonlinearization of Lax pairs. The Abel-Jacobi coordinates are introduced to straighten the flows, from which quasi-periodic solutions of the 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada equation are obtained in terms of Riemann theta functions.

  3. SPRING DRIVEN ACTUATING MECHANISM FOR NUCLEAR REACTOR CONTROL

    DOEpatents

    Bevilacqua, F.; Uecker, D.F.; Groh, E.F.

    1962-01-23

    l962. rod in a nuclear reactor to shut it down. The control rod or an extension thereof is wound on a drum as it is withdrawn from the reactor. When an emergency occurs requiring the reactor to be shut down, the drum is released so as to be free to rotate, and the tendency of the control rod or its extension coiled on the drum to straighten itself is used for quickly returning the control rod to the reactor. (AEC)

  4. Hamiltonian formalism in the equilibrium problem for a plasma with islands

    SciTech Connect

    Skovoroda, A. A.

    2011-08-15

    Hamiltonian formalism is applied to the equilibrium problem for a plasma with islands by using an analogy between the equilibrium problem for a plasma with one island and the nonlinear mechanics of a physical pendulum. A relationship is established between magnetic flux coordinates with straightened magnetic field lines and the action-angle variables. The flux and current representations of a magnetic field with islands are obtained, and the solution to the equilibrium problem for a narrow island is presented.

  5. Explicit quasi-periodic solutions of the Vakhnenko equation

    NASA Astrophysics Data System (ADS)

    Zhai, Yunyun; Geng, Xianguo; He, Guoliang

    2014-05-01

    The trigonal curve associated with the Vakhnenko equation is introduced by using the Lax matrix for the nth stationary positive flow. Based on the theory of the trigonal curve and the properties of the three kinds of Abel differentials, the Riemann theta function representation for the Baker-Akhiezer function is derived, from which the straightening out of flows in the Jacobian variety is exactly given through the Abel maps. We finally arrive at quasi-periodic solutions of the Vakhnenko equation.

  6. On the violation of Bell’s inequality for all non-product quantum states

    NASA Astrophysics Data System (ADS)

    Cafaro, Carlo; Ali, Sean Alan; Giffin, Adom

    2016-06-01

    We present an explicit reexamination of Gisin’s 1991 original proof concerning the violation of Bell’s inequality for any pure entangled state of two-particle systems. Given the relevance of Gisin’s work, our analysis is motivated by pedagogical reasons and allows the straightening of a few mathematical points in the original proof that in no way change the physical conclusions reached by Gisin.

  7. [Axis deviation of lumbar spine due to abdominal expanding lesions in children (author's transl)].

    PubMed

    Ponhold, W; Jürgenssen, O A; Balzar, E; Poplavsky, K; Püspök, R

    1981-01-01

    The deviation of the physiologic lordosis of the lumbar spine is described in 40 cases of abdominal expanding lesions. One can find a lumbar kyphosis between L2 and L4 in retroperitoneal and a straightening between Th12 and L2 in intraperitoneal lesions. The evidence of a deviation of the lumbar axis is an indirect sign for further localisation of the tumor. PMID:7254891

  8. A model of channel response in disturbed alluvial channels

    USGS Publications Warehouse

    Simon, A.

    1989-01-01

    Dredging and straightening of alluvial channels between 1959 and 1978 in West Tennessee caused a series of morphologic changes along modified reaches and tributary streams. Degradation occurred for 10 to 15 years at sites upstream of the area of maximum disturbance and lowered bed-levels by as much as 6.1 m. Following degradation, reaches upstream of the area of maximum disturbance experienced a secondary aggradation phase in response to excessive incision and gradient reduction. -from Author

  9. Minimally invasive veneers: current state of the art.

    PubMed

    Vanlıoğlu, Burçin Akoğlu; Kulak-Özkan, Yasemin

    2014-01-01

    Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers. PMID:25506248

  10. Accordion phenomenon of the hepatic artery: mimicker of vasospasm or intimal injury

    PubMed Central

    Koyama, Yoshinori; Tsushima, Yoshito

    2016-01-01

    The accordion phenomenon occurs because of mechanical distortion of a straightened vessel during coronary and vascular interventions. To date, however, this phenomenon has not been reported in vessels of the upper abdomen. We therefore describe the accordion phenomenon of the hepatic artery during transarterial chemoembolization seen while treating a liver tumor. As the accordion phenomenon is now known to involve hepatic arteries, it should be differentiated from vascular complications such as vasospasm or intimal injury. PMID:27570635

  11. Analysis of Internal Cracks in Continuous Casting Slabs with Soft Reduction

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Zhang, Jiongming; Xiao, Chao; Wang, Shunxi; Song, Wei

    2016-03-01

    The formation of internal cracks in continuous casting slabs is mainly attributed to the strain status and microsegregation near the solidifying front of the slabs. By analyzing the internal cracks of medium carbon microalloy steel, the obtained conclusions are that C, P, S, etc. enrich in dendrites and exist in grain boundaries, but these are just the internal causes, and the root cracking causes the tensile stress of solidification front. When the slab passes through the straightening segments, the liquid core thickness is large, and the liquid steel in the space of columnar crystals is not completely frozen. Therefore, the reduction effect of rollers results in the strain of solidification front exceeding the critical value. However, the corresponding strain in the arc and horizontal segments does not exceed this critical value, so the solidification front in the straightening segments would be much easy to crack. The statistics analysis shows that after soft reduction and straightening process are separately carried out, the occurrence rate of intermediate cracks is reduced by 41.3%.

  12. Spatial organization of the gravitropic response in plants: applicability of the revised local curvature distribution model to Triticum aestivum coleoptiles.

    PubMed

    Meskauskas, A; Jurkoniene, S; Moore, D

    1999-08-01

    The revised local curvature distribution model, which provides accurate computer simulations of the gravitropic response of mushroom stems, was found to produce accurate simulations of the gravitropic reaction of wheat (Triticum aestivum) coleoptiles. The key feature of the mathematical model that enables it to approach universality of application is the assumption that the stem has an autonomic straightening reaction (curvature compensation or 'autotropism'). In the model, the local bending rate for any segment of the organ is determined by the difference between the 'bending signal' (generated by the gravitropic signal perception system) and a 'straightening signal' (which is proportional to the local curvature of the segment). The model reveals three major differences between the gravitropic reactions of wheat coleoptiles and Coprinus mushroom stems. First, in Coprinus, the capacity for autonomic straightening is much more concentrated in the apical region of the stem. Second, local perception of the gravitropic signal, which is necessary for exact simulation in Coprinus, is not needed in wheat coleoptiles (the corresponding constant in the model can be set to zero). Third, the transmission rate of the gravitropic signal is about seven times faster in wheat coleoptiles than in the mushroom stem. Thus, we demonstrate that a single model, depending on the values given to its parameters, is able to simulate the spatial organization of the gravitropic reaction of wheat coleoptiles and Coprinus mushroom stems. The model promises to be a valuable predictive tool in guiding future research into the gravitropic reaction of axial organs of all types. PMID:11542912

  13. Tarantula myosin free head regulatory light chain phosphorylation stiffens N-terminal extension, releasing it and blocking its docking back.

    PubMed

    Alamo, Lorenzo; Li, Xiaochuan Edward; Espinoza-Fonseca, L Michel; Pinto, Antonio; Thomas, David D; Lehman, William; Padrón, Raúl

    2015-08-01

    Molecular dynamics simulations of smooth and striated muscle myosin regulatory light chain (RLC) N-terminal extension (NTE) showed that diphosphorylation induces a disorder-to-order transition. Our goal here was to further explore the effects of mono- and diphosphorylation on the straightening and rigidification of the tarantula myosin RLC NTE. For that we used MD simulations followed by persistence length analysis to explore the consequences of secondary and tertiary structure changes occurring on RLC NTE following phosphorylation. Static and dynamic persistence length analysis of tarantula RLC NTE peptides suggest that diphosphorylation produces an important 24-fold straightening and a 16-fold rigidification of the RLC NTE, while monophosphorylation has a less profound effect. This new information on myosin structural mechanics, not fully revealed by previous EM and MD studies, add support to a cooperative phosphorylation-dependent activation mechanism as proposed for the tarantula thick filament. Our results suggest that the RLC NTE straightening and rigidification after Ser45 phosphorylation leads to a release of the constitutively Ser35 monophosphorylated free head swaying away from the thick filament shaft. This is so because the stiffened diphosphorylated RLC NTE would hinder the docking back of the free head after swaying away, becoming released and mobile and unable to recover its original interacting position on activation. PMID:26038302

  14. A simple technique for removing the Nuss bar with one stabilizer: the lateral approach.

    PubMed

    Varela, Patricio; Romanini, Moria Victoria; Asquasciati, Caterina; Torre, Michele

    2010-02-01

    The removal of the substernal bar after the Nuss operation is not always an easy and fast maneuver. Only a few different technical solutions have been described. In the original Nuss technique, the patient was lying on dorsal decubitus and rotated on the side during the procedure. The Noguchi technique avoids the rotation of the patient, but requires two incisions and straightening of the bar before pulling it out the thorax. Recently, another technique was proposed, avoiding the need of straightening the bar, but it is feasible only if two operative beds in a large operative room are available. We propose another approach for the removal of the bar: The patient is lying on the lateral decubitus, only one incision is performed, and the bar is pulled out along the thoracic wall. Twenty-one bars were removed by using the present approach without any complications. The advantages of our approach on the previous techniques are the single incision, no need of rotating the patient, straightening the bar, or having two operative beds. Our approach is not feasible when metallic stabilizers have been used on both sides, but in our experience, this was not necessary in order to stabilize the bar. PMID:19432531

  15. Root Canal Shaping by Single-File Systems and Rotary Instruments: a Laboratory Study

    PubMed Central

    Bane, Khaly; Faye, Babacar; Sarr, Mouhamed; Niang, Seydina O; Ndiaye, Diouma; Machtou, Pierre

    2015-01-01

    Introduction: The aim of this study was to compare the shaping ability of two single-file systems and conventional rotary instruments in severely curved root canals of extracted human molars. Methods and Materials: Mesiobuccal canals of 120 mandibular molars with angles of curvature ranging between 25° and 35° and radii of curvature from 5 to 9 mm, were divided into three groups (n=40). In each group the canals were instrumented with either WaveOne (W), Reciproc (R) or ProTaper (P). The time required for canal shaping and the frequency of broken instruments were recorded. The standardized pre and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analyzed using the one-way analysis of variance (ANOVA) and post-hoc Tukey’s test. The level of significance was set at 0.05. Results: Both single-instrument systems reduced the canal preparation time by approximately 50% (P<0.05). No incidence of broken instruments from single-file systems was reported; however, two F2 instruments in the P group were broken (P<0.05). Reduction in WL and straightening of canal curvature was observed in all three systems with the highest scores belonging to P system (P<0.05). No case of blockage or perforation was found during shaping in any group. Conclusion: Single-file systems shaped curved canals with substantial saving in time and a significant decrease in incidence of instrument separation, change in WL, and straightening of canal curvature. PMID:25834600

  16. Righting response of artificially inclined maritime pine (Pinus pinaster) saplings to wind loading.

    PubMed

    Berthier, Stephane; Stokes, Alexia

    2006-01-01

    To determine if trees respond to dynamic and static loading in the same manner, 2-year-old maritime pine (Pinus pinaster Ait.) trees were subjected to different types of mechanical loading in the field. One block of trees (the control) were kept in pots and planted in the field at an angle of 0 or 45 degrees to the vertical. A similar block of leaning potted trees was planted nearby and subjected to frequent, unilateral wind loading for a period of 1 s every 2 min. Half the leaning trees were oriented toward the direction of wind loading and half were oriented along the axis of wind loading. The stem profile was measured three times during the growing season to quantify the rate of stem straightening. Compression wood formation and stem shape were measured in all plants. No differences in mean height or diameter were observed between blocks and all leaning trees straightened, but not at the same rate. Although no difference in the rate of apical straightening occurred between control and wind-treated trees, the righting response of the basal part of the stem of leaning trees subjected to wind was four times greater than that of leaning trees without wind. No differences in the righting response were observed between leaning trees growing toward and trees growing away from the source of wind. No significant differences in compression wood formation were found between control trees and wind-treated trees, indicating that other factors must determine the reorientation rate of leaning trees. Results are discussed with reference to the quality of compression wood in conifers and the mechanotransductive pathway in plants. PMID:16203716

  17. Nematic field transfer in a two-dimensional protein fibril assembly.

    PubMed

    Jordens, Sophia; Schwenke, Konrad; Usov, Ivan; Del Gado, Emanuela; Mezzenga, Raffaele

    2016-02-14

    We perform Atomic Force Microscopy and numerical simulations of a bimodal solution containing long, semiflexible β-lactoglobulin fibrils and short, flexible β-lactoglobulin linear aggregates at an air-water interface. Short aggregates orient perpendicular to fibrils at very short distances and preferentially parallel at intermediate distances. At even larger distances an isotropic distribution is observed. Parallel ordering coincides with aggregate stretching: by straightening, small aggregates are able to approach the fibrils within a distance smaller than their radius of gyration. These findings contribute to the understanding of how anisotropic interactions are transferred in two-dimensional bimodal nematic fields of biopolymers at liquid interfaces. PMID:26738771

  18. Flow quality studies of the NASA Lewis Research Center 8- by 6-foot supersonic/9- by 15-foot Low Speed Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Arrington, E. A.; Pickett, Mark T.

    1992-01-01

    A series of studies were conducted to determine the existing flow quality in the NASA Lewis 8 by 6 Foot Supersonic/9 by 15 Foot Low Speed Wind Tunnel. The information gathered from these studies was used to determine the types and designs of flow manipulators which can be installed to improve overall tunnel flow quality and efficiency. Such manipulators include honeycomb flow straighteners, turbulence reduction screens, corner turning vanes, and acoustic treatments. The types of measurements, instrumentation, and results obtained from experiments conducted at several locations throughout the tunnel loop are described.

  19. Flow quality studies of the NASA Lewis Research Center 8- by 6-foot supersonic/9- by 15-foot low speed wind tunnel

    NASA Technical Reports Server (NTRS)

    Arrington, E. Allen; Pickett, Mark T.

    1992-01-01

    A series of studies were conducted to determine the existing flow quality in the NASA Lewis 8 by 6 Foot Supersonic/9 by 15 Foot Low speed Wind Tunnel. The information gathered from these studies was used to determine the types and designs of flow manipulators which can be installed to improve overall tunnel flow quality and efficiency. Such manipulators include honeycomb flow straighteners, turbulence reduction screens, corner turning vanes, and acoustic treatments. The types of measurements, instrumentation, and results obtained from experiments conducted at several locations throughout the tunnel loop are described.

  20. Hair cosmetics: an overview.

    PubMed

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  1. Hair care and dyeing.

    PubMed

    Draelos, Zoe Diana

    2015-01-01

    Alopecia can be effectively camouflaged or worsened through the use of hair care techniques and dyeing. Proper hair care, involving hair styling and the use of mild shampoos and body-building conditioners, can amplify thinning scalp hair; however, chemical processing, including hair dyeing, permanent waving, and hair straightening, can encourage further hair loss through breakage. Many patients suffering from alopecia attempt to improve their hair through extensive manipulation, which only increases problems. Frequent haircuts to minimize split ends, accompanied by gentle handling of the fragile fibers, is best. This chapter offers the dermatologist insight into hair care recommendations for the alopecia patient. PMID:26370650

  2. Undulating membrane structure under mixed extensional-shear flow

    NASA Astrophysics Data System (ADS)

    Idziak, S. H. J.; Welch, S. E.; Kisilak, M.; Mugford, C.; Potvin, G.; Veldhuis, L.; Sirota, E. B.

    2001-10-01

    We report on studies using a new X-ray extensional flow cell to examine, for the first time, the structure of undulating lamellar lyotropic liquid crystal systems under extensional flow. The extensional component of the flow profile produced within this cell causes the lamellae to orient. We find that, although the intermembrane spacing does not change at low flow rates, it suddenly decreases after a critical flow rate has been attained due to the stretching and straightening of the lamellae. The effects of the shear component of flow on this oriented system have been examined in the context of a theoretical model developed by Ramaswamy.

  3. The application of trigonal curve to the Mikhailov-Shabat-Sokolov flows

    NASA Astrophysics Data System (ADS)

    He, Guoliang; Geng, Xianguo; Wu, Lihua

    2016-08-01

    Resorting to the characteristic polynomial of Lax matrix for the Mikhailov-Shabat-Sokolov hierarchy associated with a {3 × 3} matrix spectral problem, we introduce a trigonal curve, from which we deduce the associated Baker-Akhiezer function, meromorphic functions and Dubrovin-type equations. The straightening out of the Mikhailov-Shabat-Sokolov flows is exactly given through the Abel map. On the basis of these results and the theory of trigonal curve, we obtain the explicit theta function representations of the Baker-Akhiezer function, the meromorphic functions, and in particular, that of solutions for the entire Mikhailov-Shabat-Sokolov hierarchy.

  4. Atomistic Model of Physical Ageing in Se-rich As-Se Glasses

    SciTech Connect

    Golovchak,R.; Shpotyuk, O.; Kozdras, A.; Bureau, B.; Vlcek, M.; Ganjoo, A.; Jain, H.

    2007-01-01

    Thermal, optical, X-ray excited and magnetic methods were used to develop a microstructural model of physical ageing in Se-rich glasses. The glass composition As10Se90, possessing a typical cross-linked chain structure, was chosen as a model object for the investigations. The effect of physical ageing in this glass was revealed by differential scanning calorimetry, whereas the corresponding changes in its atomic arrangement were studied by extended X-ray absorption fine structure, Raman and solid-state 77Se nuclear magnetic resonance spectroscopy. Straightening-shrinkage processes are shown to be responsible for the physical ageing in this Se-rich As-Se glass.

  5. Dynamics of flexible fibers in shear flow

    NASA Astrophysics Data System (ADS)

    Słowicka, Agnieszka M.; Wajnryb, Eligiusz; Ekiel-JeŻewska, Maria L.

    2015-09-01

    Dynamics of flexible non-Brownian fibers in shear flow at low-Reynolds-number are analyzed numerically for a wide range of the ratios A of the fiber bending force to the viscous drag force. Initially, the fibers are aligned with the flow, and later they move in the plane perpendicular to the flow vorticity. A surprisingly rich spectrum of different modes is observed when the value of A is systematically changed, with sharp transitions between coiled and straightening out modes, period-doubling bifurcations from periodic to migrating solutions, irregular dynamics, and chaos.

  6. High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host

    DOEpatents

    Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.

    2005-07-05

    A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.

  7. Dynamics of flexible fibers in shear flow.

    PubMed

    Słowicka, Agnieszka M; Wajnryb, Eligiusz; Ekiel-Jeżewska, Maria L

    2015-09-28

    Dynamics of flexible non-Brownian fibers in shear flow at low-Reynolds-number are analyzed numerically for a wide range of the ratios A of the fiber bending force to the viscous drag force. Initially, the fibers are aligned with the flow, and later they move in the plane perpendicular to the flow vorticity. A surprisingly rich spectrum of different modes is observed when the value of A is systematically changed, with sharp transitions between coiled and straightening out modes, period-doubling bifurcations from periodic to migrating solutions, irregular dynamics, and chaos. PMID:26429038

  8. Brazilian keratin hair treatment: a review.

    PubMed

    Weathersby, Courtney; McMichael, Amy

    2013-06-01

    Brazilian keratin treatments are widely available products that are used by women all over the world to straighten hair. Marketers of these products claim that the keratin treatments render naturally curly hair more manageable and frizz-free while enhancing color and shine, giving the hair a healthier appearance. Although widely used, there have been virtually no reports of adverse side effects. Unfortunately, many of the products that are applied by salon professionals contain formaldehyde or its derivatives and are being marketed as safe. PMID:23725308

  9. Hair Cosmetics: An Overview

    PubMed Central

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  10. Turbulent dispersion via fan-generated flows

    PubMed Central

    Halloran, Siobhan K.; Wexler, Anthony S.; Ristenpart, William D.

    2014-01-01

    Turbulent dispersion of passive scalar quantities has been extensively studied in wind tunnel settings, where the flow is carefully conditioned using flow straighteners and grids. Much less is known about turbulent dispersion in the “unconditioned” flows generated by fans that are ubiquitous in indoor environments, despite the importance of these flows to pathogen and contaminant transport. Here, we demonstrate that a point source of scalars released into an airflow generated by an axial fan yields a plume whose width is invariant with respect to the fan speed. The results point toward a useful simplification in modeling of disease and pollution spread via fan-generated flows. PMID:24932096

  11. Double-diffusive fingering instability of a surfactant-glycerine-water drop in water

    NASA Astrophysics Data System (ADS)

    Kötter, K.; Markus, M.

    2001-09-01

    We present an experimental setup that allows easy visualization of single fingers formed by double diffusive convection. This setup consists of a drop (containing water and two solutes) that is injected at the bottom of a dish filled with water. The gravity-driven expansion of the drop induces a toroidal bulk flow of the surrounding water. This flow straightens and confines the fingers horizontally and quasi two-dimensionally. An extremely low diffusion coefficient of one of the two solutes (a surfactant in our case) causes unusually stable configurations. This stability is robust within a wide range of concentrations. Wavelength measurements agree well with theoretical estimations.

  12. Dynamics of flexible fibers in shear flow

    SciTech Connect

    Słowicka, Agnieszka M.; Wajnryb, Eligiusz; Ekiel-Jeżewska, Maria L.

    2015-09-28

    Dynamics of flexible non-Brownian fibers in shear flow at low-Reynolds-number are analyzed numerically for a wide range of the ratios A of the fiber bending force to the viscous drag force. Initially, the fibers are aligned with the flow, and later they move in the plane perpendicular to the flow vorticity. A surprisingly rich spectrum of different modes is observed when the value of A is systematically changed, with sharp transitions between coiled and straightening out modes, period-doubling bifurcations from periodic to migrating solutions, irregular dynamics, and chaos.

  13. An imaging and analysis toolset for the study of Caenorhabditis elegans neurodevelopment

    NASA Astrophysics Data System (ADS)

    Christensen, Ryan; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina, Javier; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter; McCreedy, Evan; Mohler, William; Bao, Zhirong; Colón-Ramos, Daniel; Shroff, Hari

    2015-03-01

    How an entire nervous system develops remains mysterious. We have developed a light-sheet microscope system to examine neurodevelopment in C. elegans embryos. Our system creates overlapping light sheets from two orthogonally positioned objectives, enabling imaging from the first cell division to hatching (~14 hours) with 350 nm isotropic resolution. We have also developed computer algorithms to computationally straighten nematode embryos, facilitating data comparison and combination from multiple animals. We plan to use these tools to create an atlas showing the position and morphology of all neurons in the developing embryo.

  14. Finite-band solutions of the coupled dispersionless hierarchy

    NASA Astrophysics Data System (ADS)

    Li, Zhu

    2016-08-01

    The coupled dispersionless hierarchy is derived with the help of the zero curvature equation. Based on the Lax matrix, we introduce an algebraic curve {{ K }}n of arithmetic genus n, from which we establish the corresponding meromorphic function ϕ, the Baker–Akhiezer function {\\varphi }1, and Dubrovin-type equations. The straightening out of all the flows is given under the Abel–Jacobi coordinates. Using the asymptotic properties of ϕ and {\\varphi }1, we obtain the explicit theta function representations of the meromorphic function ϕ, the Baker–Akhiezer function {\\varphi }1 and of solutions for the whole hierarchy.

  15. A note on the quasi-periodic solutions of the modified Boussinesq hierarchy

    NASA Astrophysics Data System (ADS)

    Wu, Lihua; He, Guoliang; Geng, Xianguo

    2015-10-01

    Based on the theory of trigonal curve and the properties of three kinds of the Abel differentials on it, we deduce the explicit theta function representations of the Baker-Akhiezer function and the meromorphic function associated with the modified Boussinesq hierarchy. The modified Boussinesq flows are straightened using the Abel map and the Lagrange interpolation formula. The explicit theta function representations of solutions for the entire modified Boussinesq hierarchy are constructed with the aid of the asymptotic properties and the algebro-geometric characters of the meromorphic function.

  16. Repositioning of Misplaced Central Venous Catheter with Saline Injection Under C-Arm Imaging

    PubMed Central

    Gautam, Parshotam Lal; Jain, Krishan; Monga, Hitika

    2015-01-01

    Malposition of central venous catheter is a well known technical complication. Misplaced catheter often requires reinsertion for proper placement of the catheter in the superior vena cava (SVC) to support safe delivery of care and minimize complications. But reinsertion exposes the patient once again to risks of complications related to the procedure including potential of misplacement. Literature describes only a few techniques for repositioning a misplaced central venous catheter (CVC). We tried old simple method of saline injection with force under image intensifier using hydrostatic force of intravenous fluid to straighten the CVC. We could successfully reposition two misplaced CVC’s using this method. PMID:26816974

  17. Finite-difference solution for turbulent swirling compressible flow in axisymmetric ducts with struts

    NASA Technical Reports Server (NTRS)

    Anderson, O. L.

    1974-01-01

    A finite-difference procedure for computing the turbulent, swirling, compressible flow in axisymmetric ducts is described. Arbitrary distributions of heat and mass transfer at the boundaries can be treated, and the effects of struts, inlet guide vanes, and flow straightening vanes can be calculated. The calculation procedure is programmed in FORTRAN 4 and has operated successfully on the UNIVAC 1108, IBM 360, and CDC 6600 computers. The analysis which forms the basis of the procedure, a detailed description of the computer program, and the input/output formats are presented. The results of sample calculations performed with the computer program are compared with experimental data.

  18. Surgical orthodontic correction of mandibular laterognathism

    PubMed Central

    Singh, Harpreet; Srivastava, Dhirendra; Kapoor, Pranav; Sharma, Poonam

    2016-01-01

    This case report describes the successful treatment of a patient with mandibular laterognathism and associated facial asymmetry with combined surgical orthodontic approach. After 7 months of presurgical orthodontic treatment, intraoral vertical ramus osteotomy, and straightening genioplasty were performed as two step surgeries to reposition the deviated mandible and chin, respectively. The total active treatment period was 14 months. After surgical orthodontic treatment, significant improvement in occlusion, masticatory function, and facial appearance was discernible. Posttreatment records at 3 years showed stable results with good occlusion. PMID:27127755

  19. Relaxation of bending stresses and the reversibility of residual stresses in amorphous soft magnetic alloys

    SciTech Connect

    Kekalo, I. B.; Mogil’nikov, P. S.

    2015-06-15

    The reversibility of residual bending stresses is revealed in ribbon samples of cobalt- and iron-based amorphous alloys Co{sub 69}Fe{sub 3.7}Cr{sub 3.8}Si{sub 12.5}B{sub 11} and Fe{sub 57}Co{sub 31}Si{sub 2.9}B{sub 9.1}: the ribbons that are free of applied stresses and bent under the action of residual stresses become completely or incompletely straight upon annealing at the initial temperatures. The influence of annealing on the relaxation of bending stresses is studied. Preliminary annealing is found to sharply decrease the relaxation rate of bending stresses, and the initial stage of fast relaxation of these stresses is absent. Complete straightening of preliminarily annealed ribbons is shown to occur at significantly higher temperatures than that of the initial ribbons. Incomplete straightening of the ribbons is explained by the fact that bending stresses relaxation at high annealing temperatures proceeds due to both reversible anelastic deformation and viscous flow, which is a fully irreversible process. Incomplete reversibility is also caused by irreversible processes, such as the release of excess free volume and clustering (detected by small-angle X-ray scattering). The revealed differences in the relaxation processes that occur in the cobalt- and iron-based amorphous alloys are discussed in terms of different atomic diffusion mobilities in these alloys.

  20. Design and prototyping of a large capacity high frequency pulse tube

    NASA Astrophysics Data System (ADS)

    Ercolani, E.; Poncet, J. M.; Charles, I.; Duband, L.; Tanchon, J.; Trollier, T.; Ravex, A.

    2008-09-01

    This document describes the design and the prototyping performed at CEA/SBT in partnership with AIR LIQUIDE of a high frequency large cooling power pulse tube. Driven at 58 Hz by a 7.5 kW flexure bearing pressure wave generator, this system provides a net heat lift of 210 W at 65 K. The phase shift is obtained by an inertance and a buffer volume. This type of cryogenic cooler can be used for on site gas liquefaction or drilling site and for high temperature superconductivity power device cooling (transmission lines, large generators, fault current limiters). In this paper, we focus on two essential points, the regenerator and the flow straightener. The regenerator is a key component for good performance of the pulse tube cooler. It must have a large thermal inertia, a low dead volume, a good heat transfer gas/matrix and at the same time, small pressure drop. In the present case and unlike typical moderate cooling power pulse tubes, the regenerator is very compact. However, the resulting conductive losses remain negligible compared to the cooling power targeted. The goal of the flow straightener is to avoid as much as possible any jet stream effect and to guarantee the uniformity of the velocity field at both ends of the pulse tube. Indeed multi-dimensional flow effects can significantly impact the performances of the machine.

  1. Quantification of interaction and topological parameters of polyisoprene star polymers under good solvent conditions

    NASA Astrophysics Data System (ADS)

    Rai, Durgesh K.; Beaucage, Gregory; Ratkanthwar, Kedar; Beaucage, Peter; Ramachandran, Ramnath; Hadjichristidis, Nikos

    2016-05-01

    Mass fractal scaling, reflected in the mass fractal dimension df, is independently impacted by topology, reflected in the connectivity dimension c , and by tortuosity, reflected in the minimum dimension dmin. The mass fractal dimension is related to these other dimensions by df=c dmin . Branched fractal structures have a higher mass fractal dimension compared to linear structures due to a higher c , and extended structures have a lower dimension compared to convoluted self-avoiding and Gaussian walks due to a lower dmin. It is found, in this work, that macromolecules in thermodynamic equilibrium display a fixed mass fractal dimension df under good solvent conditions, regardless of chain topology. These equilibrium structures accommodate changes in chain topology such as branching c by a decrease in chain tortuosity dmin. Symmetric star polymers are used to understand the structure of complex macromolecular topologies. A recently published hybrid Unified scattering function accounts for interarm correlations in symmetric star polymers along with polymer-solvent interaction for chains of arbitrary scaling dimension. Dilute solutions of linear, three-arm and six-arm polyisoprene stars are studied under good solvent conditions in deuterated p -xylene. Reduced chain tortuosity can be viewed as steric straightening of the arms. Steric effects for star topologies are quantified, and it is found that steric straightening of arms is more significant for lower-molecular-weight arms. The observation of constant df is explained through a modification of Flory-Krigbaum theory for branched polymers.

  2. Self-propelling microswimmer made of a bi-faced hydrogel

    NASA Astrophysics Data System (ADS)

    Alexeev, Alexander; Nikolov, Svetoslav V.; Yeh, Peter

    2014-03-01

    We use dissipative particle dynamics to design a new self-propelling microswimmer. Our microswimmer features a simple design and represents an X-shaped gel layer. The gel has two distinct sides or facets: one facet is responsive and swells when an external stimulus is applied, whereas the other facet is passive. We show that when an external stimulus is applied periodically, the swimmer propels itself unidirectionally in a highly viscous fluid. The propulsion is associated with periodic shape changes. When the stimulus is applied, the responsive facet swells, inducing internal stresses in the gel causing both lateral expansion and bending of the microswimmer. When the external stimulus is removed, the responsive layer contracts, and elastic forces cause the microswimmer to straighten and to recover the initial shape. The combination of the sequential expansion, bending, contraction, and straightening produces a time irreversible motion pattern leading to net propulsion at low Reynolds number. We examine how the swimming speed can be enhanced by selecting material properties and geometry of the swimmer. This work is supported by NSF CAREER award DMR-1255288.

  3. Minimally invasive scoliosis treatment with a Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Rumpf, Christian G.; Lang, Robert D.; Goetz, Marcus H.

    2000-11-01

    Today most surgical treatment of spinal deformations is concentrated on invasive mechanical techniques with long operation times and major effects on the patient's mobility. The proposed minimally invasive technique using laser light for tissue ablation offers a possibility of gentle scoliosis treatment. It is thought that an early removal of the epiphysial growth zone on the convex side over several vertebrae results in a straightening of the spine. In a first evaluation, four different laser systems including argon ion, Nd:YAG (Q-switched), Nd:YAG (cw), and Ho:YAG laser were compared with respect to thermal damage to adjacent tissue, ablation rates, efficiency and laser handling. For in-vivo investigation, fresh lamb spine was used. Comparison showed that the Ho:YAG laser is the most appropriate laser for the given goal, providing efficient photoablation with moderate thermal effects on the adjacent tissue. In a second step the proposed minimally invasive operation technique was performed in in-vivo experiments on young foxhounds using 3D- thoracoscopic operation techniques. During these operations temperature mapping was done using fiber-optic fluorescent probes. After 12 months of normal growth the animals were sacrificed and x-ray as well as MRI was performed on the spine. First results show a positive effect of scoliotic growth in two cases. Being able to produce a scoliosis by hemiepiphysiodesis on the vertebra, It is thought that this technique is successful for a straightening of the spine on patients with scoliosis.

  4. Antioxidants have a rapid and long-lasting effect on neuritic abnormalities in APP:PS1 mice.

    PubMed

    Garcia-Alloza, Monica; Borrelli, Laura A; Hyman, Bradley T; Bacskai, Brian J

    2010-12-01

    Senile plaques are a major pathological hallmark of Alzheimer's disease (AD). Compelling evidence suggests that senile plaques lead to structural alterations of neuronal processes and that local toxicity may be mediated by increased oxidative stress. Anti-oxidant therapy can alleviate the neuronal abnormalities in APP mice, but the time-course of this beneficial effect is unknown. We used multiphoton microscopy to assess in vivo the characteristics of antioxidant treatment on senile plaques and neurites in AD model mice (APPswe/PS1dE9). We observed that α-phenyl-N-tert-butyl nitrone (PBN), Ginkgo biloba extract (EGb 761) and Trolox had no effect on the size of existing senile plaques. However, all anti-oxidants had a straightening effect on curved neurites. This effect was detected as soon as 4 days after commencing the treatment, and was maintained after 1 month of daily treatment, with no further increase in the effect. The straightening of neurites persisted 15 days after stopping the treatment. These data indicate that neuronal plasticity is fast and still active in adult animals, and suggest that amelioration of the neuritic distortions associated with senile plaques with antioxidants is both rapid and long lasting. PMID:19124175

  5. Low-relief landscape modeling with human activities

    NASA Astrophysics Data System (ADS)

    Yan, Q.; Kumar, P.; Anders, A. M.

    2015-12-01

    Intensively managed landscapes (IMLs) in the Midwestern United States have been shaped by repeated glacial events over geologic time scales followed by rapid human modifications for agriculture and artificial drainage that were overlaid on extremely low gradient stream networks. These landscapes are heavily modified by agriculture, artificial drainage, deforestation, urbanization, and wetland destruction. Channel head extension and periodic dredging for channel straightening not only strongly affected hydrologic and geomorphologic response, but also fundamentally alter the energy consumption in the whole river basin. However, it is unclear how the landscape consumes and responds to the extra energy from human activities. Therefore, we evaluate the present-day dynamics of river network from the perspective of of geomorphic equilibrium, hydrological response, and the rate of energy dissipation. Then, we simulate the landscape evolution to discover the tendency of the system. We find that channel head extension and straightening increases the rate of energy dissipation and pushes the river network further away from equilibrium condition. From our numerical model simulation, extending and maintaining the ditches in the river network can cause large ridge migration, river network redistribution, and enlargement of the drainage basin area. Our research demonstrates how the river basin responds to human activities in glaciated landscape, and how it is likely to behave with artificial modifications on the topography in the future. We attribute the legacy to drainage basin reorganization and theorized that humans can have a lasting impact on the landscape even after active management has ceased.

  6. Crystal nucleation mechanism in melts of short polymer chains under quiescent conditions and under shear flow

    NASA Astrophysics Data System (ADS)

    Anwar, Muhammad; Berryman, Joshua T.; Schilling, Tanja

    2014-09-01

    We present a molecular dynamics simulation study of crystal nucleation from undercooled melts of n-alkanes, and we identify the molecular mechanism of homogeneous crystal nucleation under quiescent conditions and under shear flow. We compare results for n-eicosane (C20) and n-pentacontahectane (C150), i.e., one system below the entanglement length and one above, at 20%-30% undercooling. Under quiescent conditions, we observe that entanglement does not have an effect on the nucleation mechanism. For both chain lengths, the chains first align and then straighten locally, then the local density increases and finally positional ordering sets in. At low shear rates the nucleation mechanism is the same as under quiescent conditions, while at high shear rates the chains align and straighten at the same time. We report on the effects of shear rate and temperature on the nucleation rates and estimate the critical shear rates, beyond which the nucleation rates increase with the shear rate. In agreement with previous experimental observation and theoretical work, we find that the critical shear rate corresponds to a Weissenberg number of order 1. Finally, we show that the viscosity of the system is not affected by the crystalline nuclei.

  7. Molecular Dynamics Simulations of the Cx26 Hemichannel: Insights into Voltage-Dependent Loop-Gating

    PubMed Central

    Kwon, Taekyung; Roux, Benoît; Jo, Sunhwan; Klauda, Jeffery B.; Harris, Andrew L.; Bargiello, Thaddeus A.

    2012-01-01

    Loop-gating is one of two voltage-dependent mechanisms that regulate the open probability of connexin channels. The loop-gate permeability barrier is formed by a segment of the first extracellular loop (E1) (the parahelix) and appears to be accompanied by straightening of the bend angle between E1 and the first transmembrane domain (TM1). Here, all-atom molecular dynamics simulations are used to identify and characterize interacting van der Waals and electrostatic networks that stabilize the parahelices and TM1/E1 bend angles of the open Cx26 hemichannel. Dynamic fluctuations in an electrostatic network in each subunit are directly linked to the stability of parahelix structure and TM1/E1 bend angle in adjacent subunits. The electrostatic network includes charged residues that are pore-lining and thus positioned to be voltage sensors. We propose that the transition to the closed state is initiated by voltage-driven disruption of the networks that stabilize the open-state parahelix configuration, allowing the parahelix to protrude into the channel pore to form the loop-gate barrier. Straightening of the TM1/E1 bend appears to be a consequence of the reorganization of the interacting networks that accompany the conformational change of the parahelix. The electrostatic network extends across subunit boundaries, suggesting a concerted gating mechanism. PMID:22455917

  8. Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent

    PubMed Central

    Starosolski, Zbigniew; Villamizar, Carlos A.; Rendon, David; Paldino, Michael J.; Milewicz, Dianna M.; Ghaghada, Ketan B.; Annapragada, Ananth V.

    2015-01-01

    Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 μm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 μm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature. PMID:25985192

  9. Generating hand dysaesthesiae: the “GHD phenomenon” – straight to the diagnosis

    PubMed Central

    Lonergan, Roisin; Gorman, Grainne; Alexander, Michael D; Killeen, Ronan; de Blacam, Catherine; Tubridy, Niall

    2009-01-01

    Two Irish women presented with difficulty in completion of hair straightening, limited by upper limb dysaesthesiae due to claudication or brachial plexus entrapment induced by sustained shoulder abduction beyond 90 degrees. The first described arm pain precipitated by elevation and sustained abduction above shoulder level, particularly while using her GHD hair-straightener. Elevated arm stress test was positive and a left cervical rib was seen on chest x ray. Neurogenic thoracic outlet syndrome (TOS) was diagnosed and the cervical rib was resected. The second described arm tingling and weakness when performing tasks involving shoulder abduction and elevation, limiting GHD use to 10 min before having to rest. Upper limb blood pressure and pulses were undetectable. Erythrocyte sedimentation rate was elevated and flow on radial Doppler disappeared on abduction and elevation of each arm. A CT pulmonary angiography demonstrated features of Takayasu’s arteritis. Vascular TOS was diagnosed. Symptoms resolved with corticosteroids, followed by long-term immunosuppression and anti-coagulation. PMID:21686996

  10. Active motion assisted by correlated stochastic torques.

    PubMed

    Weber, Christian; Radtke, Paul K; Schimansky-Geier, Lutz; Hänggi, Peter

    2011-07-01

    The stochastic dynamics of an active particle undergoing a constant speed and additionally driven by an overall fluctuating torque is investigated. The random torque forces are expressed by a stochastic differential equation for the angular dynamics of the particle determining the orientation of motion. In addition to a constant torque, the particle is supplemented by random torques, which are modeled as an Ornstein-Uhlenbeck process with given correlation time τ(c). These nonvanishing correlations cause a persistence of the particles' trajectories and a change of the effective spatial diffusion coefficient. We discuss the mean square displacement as a function of the correlation time and the noise intensity and detect a nonmonotonic dependence of the effective diffusion coefficient with respect to both correlation time and noise strength. A maximal diffusion behavior is obtained if the correlated angular noise straightens the curved trajectories, interrupted by small pirouettes, whereby the correlated noise amplifies a straightening of the curved trajectories caused by the constant torque. PMID:21867138

  11. How Cellulose Stretches: Synergism between Covalent and Hydrogen Bonding

    PubMed Central

    2014-01-01

    Cellulose is the most familiar and most abundant strong biopolymer, but the reasons for its outstanding mechanical performance are not well understood. Each glucose unit in a cellulose chain is joined to the next by a covalent C–O–C linkage flanked by two hydrogen bonds. This geometry suggests some form of cooperativity between covalent and hydrogen bonding. Using infrared spectroscopy and X-ray diffraction, we show that mechanical tension straightens out the zigzag conformation of the cellulose chain, with each glucose unit pivoting around a fulcrum at either end. Straightening the chain leads to a small increase in its length and is resisted by one of the flanking hydrogen bonds. This constitutes a simple form of molecular leverage with the covalent structure providing the fulcrum and gives the hydrogen bond an unexpectedly amplified effect on the tensile stiffness of the chain. The principle of molecular leverage can be directly applied to certain other carbohydrate polymers, including the animal polysaccharide chitin. Related but more complex effects are possible in some proteins and nucleic acids. The stiffening of cellulose by this mechanism is, however, in complete contrast to the way in which hydrogen bonding provides toughness combined with extensibility in protein materials like spider silk. PMID:24568640

  12. Registration of coronary arteries in computed tomography angiography images using Hidden Markov Model.

    PubMed

    Luo, Yuxuan; Feng, Jianjiang; Xu, Miao; Zhou, Jie; Min, James K; Xiong, Guanglei

    2015-08-01

    Computed tomography angiography (CTA) allows for not only diagnosis of coronary artery disease (CAD) with high spatial resolution but also monitoring the remodeling of vessel walls in the progression of CAD. Alignment of coronary arteries in CTA images acquired at different times (with a 3-7 years interval) is required to visualize and analyze the geometric and structural changes quantitatively. Previous work in image registration primarily focused on large anatomical structures and leads to suboptimal results when applying to registration of coronary arteries. In this paper, we develop a novel method to directly align the straightened coronary arteries in the cylindrical coordinate system guided by the extracted centerlines. By using a Hidden Markov Model (HMM), image intensity information from CTA and geometric information of extracted coronary arteries are combined to align coronary arteries. After registration, the pathological features in two straightened coronary arteries can be directly visualized side by side by synchronizing the corresponding cross-sectional slices and circumferential rotation angles. By evaluating with manually labeled landmarks, the average distance error is 1.6 mm. PMID:26736676

  13. A review of surgical strategies for penile prosthesis implantation in patients with Peyronie's disease.

    PubMed

    Anaissie, James; Yafi, Faysal A

    2016-06-01

    The introduction of the inflatable penile prosthesis (IPP) has revolutionized the treatment of patients with both Peyronie's disease (PD) and erectile dysfunction (ED). A thorough literature review was performed in order to review the surgical strategies used to treat PD, using the PubMed online database with the keywords "penile prosthesis", "surgical management" and "Peyronie's disease". Patient satisfaction rates of 72-100% and partner satisfaction rates of 89% have been reported in the literature, although strong preoperative education may be needed to prepare patients for risks such as penile shortening, seen in up to 54% of patients. Three-piece IPPs are most commonly used, and when comparing the two most popular models (AMS 700 CX vs. Coloplast Titan), no significant differences were seen in functional outcomes or patient satisfaction. Simple insertion of an IPP has been shown to resolve curvature in 33-90% of patients, but surgeons may often need to also utilize ancillary straightening procedures for residual curvatures. Manual modeling can correct residual curvature with an 86-100% success rate, but with a 4% risk of urethral injury. When the post-modeling residual curvature exceeds 30 degrees, a plaque-releasing incision or plication is recommended to further reduce curvature. Grafting is recommended if the resulting incisional defect is larger than two centimeters. Alternative straightening techniques such as plication prior to IPP insertion, endoscopic plaque resection, the "scratch technique" and bone saw plaque incision have also been described. PMID:27298781

  14. Cosmetic and amino acid analysis of the effects of lye and no-lye relaxer treatment on adult black female South African hair.

    PubMed

    Mamabolo, Thabisile; Agyei, Nana M; Summers, Beverley

    2013-01-01

    Surveys indicate that many South African women use relaxers to straighten their hair for cosmetic reasons, which can damage the hair and scalp. The objective of this study was to assess the effects of treating hair with two types of relaxers: Product A (a lye relaxer, sodium hydroxide base) and Product B (a no-lye relaxer, guanidine hydroxide base). Five adult black female South African subjects were used for the study that was divided into two parts. The first part used a half-head study design in a clinical study in which the researcher and the subjects visually assessed various hair quality parameters before and after relaxer treatment. Product B was assessed to perform better (p = 0.032) than Product A in terms of hair straightening. The second part of the study involved hair amino acid analysis by reversed-phase high performance liquid chromatography. There was a decrease in the amount of cystine [Median (range) g/100 g hair] after treatment with both Product A [7.8 (2.5-9.9), p = 0.086] and Product B [4.0 (2.9-4.8), p = 0.005] compared to before treatment [9.1 (6.4-11.9)]; this decrease was greater (p = 0.085) for Product B. Reduction in cystine content was consistent with increased straightness. Product B (the no-lye relaxer) was found to be more effective and safer to use. PMID:23931091

  15. Phase errors and predicted spectral performance of a prototype undulator

    SciTech Connect

    Dejus, R.J.; Vassrman, I.; Moog, E.R.; Gluskin, E.

    1994-08-01

    A prototype undulator has been used to study different magnetic end-configurations and shimming techniques for straightening the beam trajectory. Field distributions obtained by Hall probe measurements were analyzed in terms of trajectory, phase errors, and on-axis brightness for the purpose of correlating predicted spectral intensity with the calculated phase errors. Two device configurations were analyzed. One configuration had a full-strength first magnet at each end and the next-to-last pole was recessed to make the trajectory through the middle of the undulator parallel to the undulator axis. For the second configuration, the first permanent magnet at each end was replaced by a half-strength magnet to reduce the trajectory displacement and the next-to-last pole was adjusted appropriately, and shims were added to straighten the trajectory. Random magnetic field errors can cause trajectory deviations that will affect the optimum angle for viewing the emitted radiation, and care must be taken to select the appropriate angle when calculating the phase errors. This angle may be calculated from the average trajectory angle evaluated at the location of the poles. For the second configuration, we find an rms phase error of less than 3{degrees} and predict 87% of the ideal value of the on-axis brightness for the third harmonic. We have also analyzed the gap dependence of the phase errors and spectral brightness and have found that the rms phase error remain small at all gap settings.

  16. Measuring Outdoor Air Intake Rates into Existing Building

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2009-04-16

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  17. Applications of Self-Referencing Method to the Virgo Cluster Spirals

    NASA Astrophysics Data System (ADS)

    Chung, Eun Jung; Kim, Hyoryoung; Rhee, Myung-Hyun

    2005-12-01

    Self-referencing method in revised-OTFTOOL is a new method in On-The-Fly(OTF) observation mode. It uses the source free regions of the observed frame as references instead of the OFFs references. We already analyzed and discussed its proprieties and advantages in the previous paper. In this paper, we make a statistical study about the self-referencing method by applying it to OTF mapping data of 27 Virgo spiral galaxies. We found that the self-referencing method solves the crooked baseline problem for every datacube. It straightens the baseline, and conserves the emissions. Compared with other data processing, the median filtering task' mwflt' in AIPS, to use self-referencing method is more effective and safe not only to straighten the baseline but also to conserve the emission. For the strong CO galaxies, the data obtained by self-referencing method shows scarcely any difference from those reduced by conventional OFFs references and AIPS median filtering in the range of uncertainties. Undetected CO emissions in datacubes of conventional OFFs references are also not detected in those of self-referencing method. The self-referencing method is expected to save the observing time and simplify data reduction processes. Besides this, using self-referencing method will offer emission-free references more safely.

  18. Ho:YAG laser in reshaping tracheal cartilage: a pilot investigation using ex vivo porcine and rabbit cartilage

    NASA Astrophysics Data System (ADS)

    Lam, Anthony; Protsenko, Dmitry E.; Carbone, Nicholas; Li, Chao; Jackson, Ryan; Wong, Brian J.

    2004-07-01

    Stenotic, collapsed, and flow-restricted tracheal airways may result from blunt trauma, chronic infection, and the prolonged endotracheal intubation. This pilot investigation characterizes the degree of shape change produced by Ho:YAG laser (λ=2.12 μm) irradiation of rabbit and pig trachea tissue as a function of laser dosimetry and application protocol. Force displacement curves were generated using fresh lagomorph and porcine tracheal cartilage rings secured in a modified single beam cantilever geometry. These specimens were then irradiated for varying amounts of time and power with the objective of straightening these curved specimens. The degree of shape change was documented photographically. Force and surface temperature were monitored. Confocal microscopy was then used in combination a vital staine ("live-dead assay") to determine the level of viability of straightened cartilage for selected exposure time-power pairs. Laser Cartilage Reshaping of the trachea may provide a new method to treat severe tracheal injuries without the need for classic open surgical techniques. This pilot investigation is the first step toward demonstrating the feasibility of this technique. Long-term, the design of stents combined with laser irradiation may provide a means to alter tracheal shape.

  19. Thoracic endovascular aortic repair of a severely angulated aorta using a double-wire technique

    PubMed Central

    Kawatani, Yohei; Nakamura, Yoshitsugu; Hayashi, Yujiro; Taneichi, Tetsuyoshi; Ito, Yujiro; Kurobe, Hirotsugu; Suda, Yuji; Hori, Takaki

    2016-01-01

    When endovascular treatment is performed, angulation of the access route for a device can make the operative procedure difficult. We encountered a case in which we successfully completed thoracic endovascular aortic repair (TEVAR) in a patient with severely angulated aorta by applying ‘double-wire technique’. The patient was an 80-year-old woman. An aneurysm with a 71-mm diameter was observed in the descending aorta. We performed TEVAR. Device delivery could not be achieved by a conventional procedure using one guide wire since the peripheral aorta was severely angulated. Therefore, in addition to a guide wire for main body, a stiff wire and a stiff sheath were introduced to straighten the angulation. The device was successfully introduced and TEVAR was completed. We used the Relay Plus® that facilitates tracking through the angulation. The device has a dual structure consisting of a hard sheath and a flexible sheath. We performed TEVAR successfully. PMID:27421301

  20. On the tear resistance of skin

    DOE PAGESBeta

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-03-27

    Tear resistance is vitally important for the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. Here we explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. Finally, we express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensilemore » direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.« less

  1. A method of calibrating wind velocity sensors with a modified gas flow calibrator

    NASA Technical Reports Server (NTRS)

    Stump, H. P.

    1978-01-01

    A procedure was described for calibrating air velocity sensors in the exhaust flow of a gas flow calibrator. The average velocity in the test section located at the calibrator exhaust was verified from the mass flow rate accurately measured by the calibrator's precision sonic nozzles. Air at elevated pressures flowed through a series of screens, diameter changes, and flow straighteners, resulting in a smooth flow through the open test section. The modified system generated air velocities of 2 to 90 meters per second with an uncertainty of about two percent for speeds below 15 meters per second and four percent for the higher speeds. Wind tunnel data correlated well with that taken in the flow calibrator.

  2. Improvement of the Chairs in Classrooms for Better Sitting Posture of Children

    NASA Astrophysics Data System (ADS)

    Ishihara, Keiko; Dake, Kazuo; Ishihara, Shigekazu

    2010-10-01

    We sought to improve the sitting postures of children studying in the classrooms of a primary school. We made the seat of a standard chair lower and attached a cushion designed by one of the authors. The cushion is cut at a 25° downward angle toward the legs to allow the users to support their weight with their feet and alleviate pressure on the underside of the thighs. We also lowered the desktop to below the height of children's elbows. Eighty-three children were given the new chairs and desks, and they were observed over 7 months. Around 10% of them voluntarily maintained good sitting postures; others straightened their postures when the teachers reminded them to do so.

  3. The role of nodal and internodal responses in gravitropism and autotropism in Galium aparine L

    NASA Technical Reports Server (NTRS)

    Heathcote, D. G.; Brown, A. H. (Principal Investigator)

    1987-01-01

    This time course and location of gravitropically induced curvatures in stems of goosegrass (Gallium aparine L.), a member of the Rubiaceae, have been investigated. In the early stages of the response (0-5 h), curvature develops throughout the growing region, and is followed by an autotropic straightening which affects the internodes only, leading to the production of essentially straight internodes some 15 h after the onset of gravistimulation. Curvatures developing in the nodal regions, however, continue to increase over this period, and are not subject to reversal by autotropism. The nodal curvatures are not entirely dependent on the presence of any other part of the plant, since marked curvatures can be induced in isolated nodal segments. This pattern of response leads ultimately to correction of the growth direction of the plant by means of curvature responses confined exclusively to the nodes, despite the initial participation of both nodes and internodes in the gravitropic reaction.

  4. Cerebral arteriopathy associated with Arg179His ACTA2 mutation

    PubMed Central

    Amans, Matthew R; Stout, Charles; Fox, Christine; Narvid, Jared; Hetts, Steven W; Cooke, Daniel L; Higashida, Randall T; Dowd, Christopher F; McSwain, Hugh; Halbach, Van V

    2013-01-01

    ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae. PMID:24293535

  5. Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform

    USGS Publications Warehouse

    Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

    2005-01-01

    Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

  6. Stretching and ordering of amyloid fibrils at liquid interfaces

    NASA Astrophysics Data System (ADS)

    Del Gado, Emanuela; Schwenke, Konrad; Jordens, Sophia; Usov, Ivan; Mezzenga, Raffaele; Georgetown University Team; ETH Zurich Team

    We investigate the formation of nematic domains, which might be precursor of plaque formation, in the adsorption of amyloid fibrils at liquid interfaces. Combining experiments and computer simulations we analyse spatial correlations in the nematic order and in apparent persistence length. Non-equilibrium numerical simulations provide new insight into the coupling between those quantities. The emerging scenario is that the out-of-equilibrium adsorption favors the formation of spatial heterogeneities due to the presence of local nematic order that tend to persist upon increasing the surface coverage. Such structural heterogeneities are directly coupled to the apparent straightening of the brils and might affect the density and the mechanical properties of the final self-assembled material.

  7. Withdrawing method of the stiffening tube incidentally inserted into the descending colon.

    PubMed

    Fukuda, Shinsaku; Mikami, Tatsuya; Shimoyama, Tadashi; Hanabata, Norihiro; Iwamura, Hideki; Munakata, Akihiro

    2005-09-14

    We experienced a very rare complication of colonoscopy, a migration of stiffening tube into the colorectum. We herein introduce a withdrawing method of migrating stiffening tube incidentally inserted into the colorectum. A 65-year-old Japanese woman underwent colonoscopy because of abdominal discomfort. We used stiffening tube to insert the scope to the proximal colon because of her redundant sigmoid colon. When withdrawing the scope, we realized that the tube was fully inside the colorectum. We could not remove the tube instantly, and it reached the splenic flexure, finally. We reinserted the scope through the migrating tube, straightened the scope, and withdrew it holding a slight angle of the scope over the proximal end of the tube. Then, we could safely remove the tube along with the scope through the anus. PMID:16149153

  8. NASA Benefits Earth

    NASA Technical Reports Server (NTRS)

    Robinson, Julie A.

    2009-01-01

    This slide presentation reviews several ways in which NASA research has benefited Earth and made life on Earth better. These innovations include: solar panels, recycled pavement, thermometer pill, invisible braces for straightening teeth, LASIK, aerodynamic helmets and tires for bicycles, cataract detection, technology that was used to remove Anthrax spores from mail handling facilities, study of atomic oxygen erosion of materials has informed the restoration of artwork, macroencapsulation (a potential mechanism to deliver anti cancer drugs to specific sites), and research on a salmonella vaccine. With research on the International Space Station just beginning, there will be opportunities for entrepreneurs and other government agencies to access space for their research and development. As well as NASA continuing its own research on human health and technology development.

  9. Endoscopes and robots for tight surgical spaces: use of precurved elastic elements to enhance curvature

    NASA Astrophysics Data System (ADS)

    Remirez, Andria A.; Webster, Robert J.

    2016-03-01

    Many applications in medicine require flexible surgical manipulators and endoscopes capable of reaching tight curvatures. The maximum curvature these devices can achieve is often restricted either by a strain limit, or by a maximum actuation force that the device's components can tolerate without risking mechanical failure. In this paper we propose the use of precurvature to "bias" the workspace of the device in one direction. Combined with axial shaft rotation, biasing increases the size of the device's workspace, enabling it to reach tighter curvatures than a comparable device without biasing can achieve, while still being able to fully straighten. To illustrate this effect, we describe several example prototype devices which use flexible nitinol strips that can be pushed and pulled to generate bending. We provide a statics model that relates the manipulator curvature to actuation force, and validate it experimentally.

  10. Van der Waals forces in the perfluorinated metal-organic framework zinc 1,2-bis(4-pyridyl)ethane tetrafluoroterephthalate.

    PubMed

    Chang, Bor Kae; Bristowe, Nicholas C; Bristowe, Paul D; Cheetham, Anthony K

    2012-05-21

    Traditional density functional theory (DFT) and dispersion-corrected DFT calculations are performed to investigate the metal-organic framework zinc 1,2-bis(4-pyridyl)ethane tetrafluoroterephthalate (Znbpetpa). Without dispersion correction, straightening of the zigzag C-O-Zn chain connecting the secondary building units across the diagonal of the unit cell is observed, accompanied by a large anisotropic expansion of the structure along one cell parameter. The results show that van der Waals dispersion forces and specifically Zn-C equatorial interactions and the resulting effects on the zigzag chain play an important role in maintaining key structural features which match with experimental observations. It is suggested that the pore volume of the framework could be controlled by substituting the Zn metal centre with another transition element of different polarizability, while maintaining functional linkers. PMID:22482115

  11. [Polychromatic method of simultaneously demonstrating all the structural components of a peripheral nerve].

    PubMed

    Dolishniĭ, N V; Mel'man, E P

    1978-02-01

    To study neuro-vessel relations in the nerve conductive system, a combined method revealing myelinated and non-myelinated nerve fibers and blood vessels was suggested. The method includes the following stages of material treatment: injection of the nerve blood vessels with chloroform emulsion of Paris blue (5--10 g of the dye in 100 g of the solvant); the straightened nerves about 5 mm long are fixed in 12% neutral formalin; etching in the solution of chromium solts; embedding in paraffin and preparation of thin sections (3--5 mcm); staining after Masson's method applied for collagen fiber staining) in the author's modification and mounting in balsam. In the preparations, the axons of the nerve fibers are seen blue--purple, myelin sheaths--light red, connective tissue elements--violet and blood vessels are seen as dark blue rings. PMID:77154

  12. S-192 analysis: Conventional and special data processing techniques. [Michigan

    NASA Technical Reports Server (NTRS)

    Nalepka, R. F. (Principal Investigator); Morganstern, J.; Cicone, R.; Sarno, J.; Lambeck, P.; Malila, W.

    1975-01-01

    The author has identified the following significant results. Multispectral scanner data gathered over test sites in southeast Michigan were analyzed. This analysis showed the data to be somewhat deficient especially in terms of the limited signal range in most SDOs and also in regard to SDO-SDO misregistration. Further analysis showed that the scan line straightening algorithm increased the misregistration of the data. Data were processed using the conic format. The effects of such misregistration on classification accuracy was analyzed via simulation and found to be significant. Results of employing conventional as well as special, unresolved object, processing techniques were disappointing due, at least in part, to the limited signal range and noise content of the data. Application of a second class of special processing techniques, signature extension techniques, yielded better results. Two of the more basic signature extension techniques seemed to be useful in spite of the difficulties.

  13. Cerebral arteriopathy associated with Arg179His ACTA2 mutation.

    PubMed

    Amans, Matthew R; Stout, Charles; Fox, Christine; Narvid, Jared; Hetts, Steven W; Cooke, Daniel L; Higashida, Randall T; Dowd, Christopher F; McSwain, Hugh; Halbach, Van V

    2013-01-01

    ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae. PMID:24293535

  14. Cerebral arteriopathy associated with Arg179His ACTA2 mutation.

    PubMed

    Amans, Matthew R; Stout, Charles; Fox, Christine; Narvid, Jared; Hetts, Steven W; Cooke, Daniel L; Higashida, Randall T; Dowd, Christopher F; McSwain, Hugh; Halbach, Van V

    2014-11-01

    ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae. PMID:24353327

  15. Bending strain tolerance of MgB2 superconducting wires

    NASA Astrophysics Data System (ADS)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  16. On the tear resistance of skin.

    PubMed

    Yang, Wen; Sherman, Vincent R; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O; Meyers, Marc A

    2015-01-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip. PMID:25812485

  17. Cy3-DNA Stacking Interactions Strongly Depend on the Identity of the Terminal Basepair

    PubMed Central

    Spiriti, Justin; Binder, Jennifer K.; Levitus, Marcia; van der Vaart, Arjan

    2011-01-01

    We characterized the effect of the first basepair on the conformational dynamics of the fluorescent dye Cy3 attached to the 5′ end of double-stranded DNA using Gaussian-mixture adaptive umbrella sampling simulations. In the simulations, the sampling of all five dihedral angles along the linker was enhanced, so that both stacked and unstacked states were sampled. The affinity of Cy3 for a T·A basepair (with the dye attached to T) was found to be significantly less than for the other basepairs. This was verified experimentally by measuring the activation energies for cis-trans isomerization of the dye. The simulation and experimental results indicate the existence of partially unstacked conformations amenable to photoisomerization. The simulations also showed that stacking of Cy3 straightens the DNA while stabilizing the first basepair. Our findings indicate that fluorescence is modulated by Cy3-DNA interactions in a sequence-dependent manner. PMID:21320450

  18. Thoracic endovascular aortic repair of a severely angulated aorta using a double-wire technique.

    PubMed

    Kawatani, Yohei; Nakamura, Yoshitsugu; Hayashi, Yujiro; Taneichi, Tetsuyoshi; Ito, Yujiro; Kurobe, Hirotsugu; Suda, Yuji; Hori, Takaki

    2016-01-01

    When endovascular treatment is performed, angulation of the access route for a device can make the operative procedure difficult. We encountered a case in which we successfully completed thoracic endovascular aortic repair (TEVAR) in a patient with severely angulated aorta by applying 'double-wire technique'. The patient was an 80-year-old woman. An aneurysm with a 71-mm diameter was observed in the descending aorta. We performed TEVAR. Device delivery could not be achieved by a conventional procedure using one guide wire since the peripheral aorta was severely angulated. Therefore, in addition to a guide wire for main body, a stiff wire and a stiff sheath were introduced to straighten the angulation. The device was successfully introduced and TEVAR was completed. We used the Relay Plus(®) that facilitates tracking through the angulation. The device has a dual structure consisting of a hard sheath and a flexible sheath. We performed TEVAR successfully. PMID:27421301

  19. Nanoscale manipulation of Ge nanowires by ion hammering

    SciTech Connect

    Picraux, Samuel T; Romano, Lucia; Rudawski, Nicholas G; Holzworth, Monta R; Jones, Kevin S; Choi, S G

    2009-01-01

    Nanowires generated considerable interest as nanoscale interconnects and as active components of both electronic and electromechanical devices. However, in many cases, manipulation and modification of nanowires are required to realize their full potential. It is essential, for instance, to control the orientation and positioning of nanowires in some specific applications. This work demonstrates a simple method to reversibly control the shape and the orientation of Ge nanowires by using ion beams. Initially, crystalline nanowires were partially amorphized by 30 keY Ga+-implantation. After amorphization, viscous flow and plastic deformation occurred due to the ion hammering effect, causing the nanowires to bend toward the beam direction. The bending was reversed multiple times by ion-implanting the opposite side of the nanowires, resulting in straightening of the nanowires and subsequent bending in the opposite direction. This ion hammering effect demonstrates the detailed manipulation of nanoscale structures is possible through the use of ion irradiation.

  20. Another Estimate for the Percentage of Partly Embayed Craters in Equilibrium Resurfacing

    NASA Astrophysics Data System (ADS)

    Muinonen, P. J.

    1996-03-01

    When choosing between different scenarios of Venus' resurfacing history, one of the objections against an Equilibrium Resurfacing Model (ERM) is an apparent lack of craters that have suffered a partial embayment by lava flows of outside origin. Any test of ERM so far, be it numeric or analytic in nature, has failed to predict anything even near the observed ~5% of partly embayed craters (PECs) without violating the statistics of crater distribution. This study is mainly based on straightening out as many as possible of the simplifications that have been employed while estimating the statistical implications of the ERM. As a result, the expectation value for PECs falls to less than 10% from previous ~30%.

  1. Peyronie's Reconstruction for Maximum Length and Girth Gain: Geometrical Principles

    PubMed Central

    Egydio, Paulo H.; Sansalone, Salvatore

    2008-01-01

    Peyronie's disease has been associated with penile shortening and some degree of erectile dysfunction. Surgical reconstruction should be based on giving a functional penis, that is, rectifying the penis with rigidity enough to make the sexual intercourse. The procedure should be discussed preoperatively in terms of length and girth reconstruction in order to improve patient satisfaction. The tunical reconstruction for maximum penile length and girth restoration should be based on the maximum length of the dissected neurovascular bundle possible and the application of geometrical principles to define the precise site and size of tunical incision and grafting procedure. As penile rectification and rigidity are required to achieve complete functional restoration of the penis and 20 to 54% of patients experience associated erectile dysfunction, penile straightening alone may not be enough to provide complete functional restoration. Therefore, phosphodiesterase inhibitors, self-injection, or penile prosthesis may need to be added in some cases. PMID:19081785

  2. Preservation of Cavernosal Erectile Function after Soft Penile Prosthesis Implant in Peyronie's Disease: Long-Term Followup

    PubMed Central

    Grasso, Marco; Lania, Caterina; Fortuna, Flavio; Blanco, Salvatore; Piacentini, Igor

    2008-01-01

    The aim of this retrospective study is to evaluate the long-term followup of soft penile SSDA prosthesis, without plaque surgery in the treatment of Peyronie's disease. This study included 12 men with Peyronie's disease who underwent placement of a penile prosthesis. All patients were followed for at least 6 years. Prosthesis straightened the penile shaft in all cases, restoring patient sexual satisfaction. No operative or postoperative complications occurred, and no reoperations were needed. All patients have undergone further examination with basal and dynamic eco color Doppler. The findings are encouraging as the penis preserves the ability to enhance the tumescence and penile girth. We can conclude that SSDA penile prosthesis is safe and effective in Peyronie's disease. PMID:19081839

  3. A Min-Time Analysis of Three Trajectories with Curvature and Nonholonomic Constraints Using a Parallel Parking Criterion

    NASA Astrophysics Data System (ADS)

    Lyon, Douglas

    This paper presents a comparison of three s-shaped curves for parallel parking a car subject to nonholonomic constraints. The comparison is based on the rate at which the car approaches the curb (the parking criterion). The curves (two circular arcs, a cosine curve and a quintic) are shown to accommodate an initial and final position, but only the quintic accommodates initial and final curvature. The time penalty in straightening out the wheels at the maneuver end-points (or midpoint) causes the other curves to be suboptimal. Representative examples of the curves are shown. Also illustrated is the effect of the turning radius of the car on the time required to park it.

  4. Recent Developments in Ground-Borne Noise and Vibration Control

    NASA Astrophysics Data System (ADS)

    Nelson, J. T.

    1996-05-01

    Vibration control provisions available to the transit designer include (among others) precision straightened rail, ballast mats, floating slabs and very soft direct fixation fasteners, in addition to rail grinding, wheel truing, and continuous welded rail. Recently, the Los Angeles Metro has developed specifications for a soft resilient direct fixation fastener to fit the same base dimensions as the standard direct fixation fastener. In San Francisco, low resonance frequency (8 Hz) floating slabs have been constructed to mitigate predicted ground vibration impacts at nearby residential structures. In Atlanta, low resonance frequency loading slabs have been constructed to maintain a low vibration environment in a medical building planned to be built over the subway structure. In Portland and Pasadena, ballast mats have been recommended to control light rail transit ground vibration impacts on housing located at typically 35 feet from the alignment. Each of these provisions are briefly described in view of recent applications at U.S. transit systems.

  5. Spectrum of mucocutaneous manifestations in human immunodeficiency virus-infected patients and its correlation with CD4 lymphocyte count.

    PubMed

    Fernandes, Michelle S; Bhat, Ramesh M

    2015-05-01

    In this study, 100 HIV-positive cases (63 men, 37 women) with skin findings were included. The mean CD4 T cell count was 253 cells/mm(3). A total of 235 dermatological manifestations were seen. The common infectious dermatoses were candidiasis (21%), Staphylococcal skin infections (20%), dermatophytoses (14%) and herpes zoster (6%). Among the non-infectious dermatoses were papular pruritic eruptions (20%), xerosis/ichthyosis (20%) and seborrhoeic dermatitis (16%). Statistically significant association (p < 0.05) with CD4 T cell count was seen in pyodermas, dermatophytoses and papular pruritic eruptions. Adverse drug reactions, diffuse hair loss, straightening of hairs and pigmentary changes were also noted. Although there was an absence of Kaposi's sarcoma in our study, a case of verrucous carcinoma of penis was noted. PMID:25015936

  6. A 22-year follow-up of the nonsurgical expansion of maxillary and mandibular arches in a young adult: Are the outcomes stable, relapsed, or unstable with aging?

    PubMed

    Valladares-Neto, José; Evangelista, Karine; Miranda de Torres, Hianne; Melo Pithon, Matheus; Alves Garcia Santos Silva, Maria

    2016-09-01

    Adult maxillary and mandible arch expansion without a surgical approach can be uncertain when long-term stability is considered. This case report describes the treatment of a 19-year-old woman with an Angle Class I malocclusion with constricted maxillary and mandibular arches. The patient's main complaint was mandibular anterior crowding. The treatment plan included expansion of the mandibular arch concurrent with semirapid maxillary expansion. An edgewise appliance was used to adjust the final occlusion. Smile esthetics and dental alignment were improved without straightening the profile. This outcome was followed up with serial dental casts for 22 years after treatment. At the end of that period, the occlusion and tooth alignment were clinically satisfactory, further supported by mandibular fixed retention. However, the transverse widths were continuously and gradually reduced over time, superposing orthodontic transverse relapse and natural arch constriction caused by aging. PMID:27585782

  7. Functions of plant-specific myosin XI: from intracellular motility to plant postures.

    PubMed

    Ueda, Haruko; Tamura, Kentaro; Hara-Nishimura, Ikuko

    2015-12-01

    The plant-specific protein motor class myosin XI is known to function in rapid bulk flow of the cytoplasm (cytoplasmic streaming) and in organellar movements. Recent studies unveiled a wide range of physiological functions of myosin XI motors, from intracellular motility to organ movements. Arabidopsis thaliana has 13 members of myosin XI class. In vegetative organs, myosins XIk, XI1, and XI2 primarily contribute to dynamics and spatial configurations of endoplasmic reticulum that develops a tubular network in the cell periphery and thick strand-like structures in the inner cell regions. Myosin XI-i forms a nucleocytoplasmic linker and is responsible for nuclear movement and shape. In addition to these intracellular functions, myosin XIf together with myosin XIk is involved in the fundamental nature of plants; the actin-myosin XI cytoskeleton regulates organ straightening to adjust plant posture. PMID:26432645

  8. Numerical simulation of MHD pulsatile flow of a biofluid in a channel

    NASA Astrophysics Data System (ADS)

    Ali, Kashif; Ahmad, Shahzad; Ashraf, Muhammad

    2015-08-01

    The purpose of this paper is to numerically study the interaction of an external magnetic field with the flow of a biofluid through a Darcy-Forchhmeir porous channel, due to an oscillatory pressure gradient, in the presence of wall transpiration as well as chemical reaction considerations. We have noticed that if the Reynolds number of the wall transpiration flow is increased, the average (or maximum) velocity of the main flow direction is raised. Similar effect has also been observed for the rheological parameter and the Darcy parameter, whereas an opposite trend has been noted for both the Forchheimer quadratic drag parameter and the magnetic parameter. Further, an increase in the Reynolds number results in straightening the concentration profile, thus making it an almost linear function of the dimensionless spatial variable.

  9. Dental Arch Wire

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Straightening teeth is an arduous process requiring months, often years, of applying corrective pressure by means of arch wires-better known as brace-which may have to be changed several times in the course of treatment. A new method has been developed by Dr. George Andreasen, orthodontist and dental scientist at the University of Iowa. The key is a new type of arch wire material, called Nitinol, with exceptional elasticity which helps reduce the required number of brace changes. An alloy of nickel and titanium, Nitinol was originally developed for aerospace applications by the Naval Ordnance Laboratory, now the Naval Surface Weapons Laboratory, White Oaks, Maryland. NASA subsequently conducted additional research on the properties of Nitinol and on procedures for processing the metal.

  10. Translational control of a graphically simulated robot arm by kinematic rate equations that overcome elbow joint singularity

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Houck, J. A.; Carzoo, S. W.

    1984-01-01

    An operator commands a robot hand to move in a certain direction relative to its own axis system by specifying a velocity in that direction. This velocity command is then resolved into individual joint rotational velocities in the robot arm to effect the motion. However, the usual resolved-rate equations become singular when the robot arm is straightened. To overcome this elbow joint singularity, equations were developed which allow continued translational control of the robot hand even though the robot arm is (or is nearly) fully extended. A feature of the equations near full arm extension is that an operator simply extends and retracts the robot arm to reverse the direction of the elbow bend (difficult maneuver for the usual resolved-rate equations). Results show successful movement of a graphically simulated robot arm.

  11. Weld bead reinforcement removal: A method of improving the strength and ductility of peaked welds in 2219-T87 aluminum alloy plate

    NASA Technical Reports Server (NTRS)

    Lovoy, C. V.

    1979-01-01

    The results of a study to determine the degree to which the ductility and tensile properties of peaked welds could be enhanced by removing the reinforcing bead and fairing the weld nugget into the adjacent parent metal are presented. The study employed 2219-T87 aluminum alloy plate, tungsten inert gas (TIG) welding, and 2319 filler wire. The study concluded that significant improvements in peak weld, ultimate strength, and ductility can be obtained through removal and fairing of the weld reinforcing bead. The specimens so treated and tested in this program exhibited ultimate strength improvements of 2 to 3 percent for peak angles of 5.8 to 10 degrees and 10 to 22 percent for welds with peak angles of 11.7 to 16.9 degrees. It was also determined that removal of the weld bead enhanced the ability of peaked welds to straighten when exposed to cyclic loading at stress levels above the yield strength.

  12. The wire anchor loop traction (WALT) maneuver.

    PubMed

    Effendi, Khaled; Sacho, Raphael Hillel; Belzile, François; Marotta, Thomas R

    2016-02-01

    Crossing the neck of large complex intracranial aneurysms for the purposes of stent deployment can be challenging using standard over the wire techniques. We describe a novel yet simple technique for straightening out the loop formed within a large intracranial aneurysm, which is often required in order to cross the aneurysm neck into the distal branch. Both the microcatheter and microwire are initially introduced into the distal vasculature, followed by withdrawal of the microwire to a point parallel to the distal exiting branch. The microcatheter and microwire are then gently withdrawn and a series of maneuvers to gradually reduce the loop is performed, obviating the need for distal purchase in the form of a stent, balloon, or coil, which have previously been described to maintain distal purchase. PMID:25634903

  13. On load paths and load bearing topology from finite element analysis

    NASA Astrophysics Data System (ADS)

    Kelly, D.; Reidsema, C.; Lee, M.

    2010-06-01

    Load paths can be mapped from vector plots of 'pointing stress vectors'. They define a path along which a component of load remains constant as it traverses the solution domain. In this paper the theory for the paths is first defined. Properties of the plots that enable a designer to interpret the structural behavior from the contours are then identified. Because stress is a second order tensor defined on an orthogonal set of axes, the vector plots define separate paths for load transfer in each direction of the set of axes. An algorithm is therefore presented that combines the vectors to define a topology to carry the loads. The algorithm is shown to straighten the paths reducing bending moments and removing stress concentration. Application to a bolted joint, a racing car body and a yacht hull demonstrate the usefulness of the plots.

  14. Changing Pathology of the Thoracic Aorta From Acute to Chronic Dissection: Literature Review and Insights.

    PubMed

    Peterss, Sven; Mansour, Ahmed M; Ross, Julia A; Vaitkeviciute, Irena; Charilaou, Paris; Dumfarth, Julia; Fang, Hai; Ziganshin, Bulat A; Rizzo, John A; Adeniran, Adebowale J; Elefteriades, John A

    2016-09-01

    We review current knowledge regarding the natural transition of aortic dissection from acute to chronic stages. As this is not well understood, we also bring to bear new data from our institution. Type A dissection rarely transitions naturally into the chronic state; consequently, information is limited. Type B dissections are routinely treated medically and indeed undergo substantial changes during their temporal course. General patterns include: 1) the aorta dilates and, absent surgical intervention, aortic enlargement may cause mortality; 2) continued false lumen patency, particularly with an only partially thrombosed false lumen, increases aortic growth, whereas calcium-channel blockers affect aortic dilation favorably; 3) aortic dilation manifests a temporal dynamic, with early rapid growth and deceleration during transition; 4) the intimal flap dynamically changes over time via thickening, straightening, and loss of mobility; and 5) temporal remodeling, on the cellular level, initially shows a high grade of wall destruction; subsequently, significant fibrosis ensues. PMID:27585511

  15. Adaptive correction of the focused beam in conditions with strong fluctuations of intensity

    NASA Astrophysics Data System (ADS)

    Lukin, Vladimir P.; Fortes, Boris V.

    2000-07-01

    The adaptive correction was frequently treated as straightening of wavefront, if deal with receiving of the deformed wave. For adaptive focusing of beams the correction was considered as predistortion of wavefront. However with infringement of a condition smoothness of wavefront, the situation varies. It is known, that dislocations of wavefront conterminous to points where instant meaning of intensity equal to zero, arise with distances approximately equal diffraction length. With presence of such points the wavefront of a reference wave cannot be determined as a smooth one-coherent surface, therefore efficiency of adaptive systems with flexible mirrors begins to be reduced. At the same time, the numerical experiment with model of a compound phase corrector has shown, that its efficiency practically does not change with transition in area of strong fluctuations of intensity. We have found out, that the efficiency of adaptive system with a compound corrector does not vary with transition from area weak fluctuations of intensity in area strong fluctuations.

  16. Evaluation of microfilaricidal effects in the cornea from topically applied drugs in ocular onchocerciasis: Trials with levamisole and mebendazole.

    PubMed Central

    Jones, B R; Anderson, J; Fuglsang, H

    1978-01-01

    Increasing concentrations of levamisole and of mebendazole were applied to 1 eye in groups of 4 patients with ocular onchocerciasis in northern Cameroon. No effect resulted from up to 3.0% mebendazole suspensions, but 3.0% levamisole solutions rapidly caused entry of microfilariae, straightening out and subsequent opacification of previously curled-up living microfilariae, the rapid formation of typical limbal globular infiltrates, and the subsequent formation of fluffy opacities around the microfilariae. These changes are typical of all other drugs so far studied that have a microfilaricidal action on O. volvulus--diethlycarbamizine citrate (DEC), suramin, and metrifonate. The efficacy of 3.0% levamisole approximated to that of 0.03% DEC. This is in keeping with published observations on the filaricidal activity of these 2 compounds. It is suggested that this system of drug testing should be considered for systematic use in the search for more effective and safer drugs for onchocerciasis. Images PMID:678495

  17. Plasmastatic models of galathea traps with magnetically transparent boundaries

    NASA Astrophysics Data System (ADS)

    Brushlinskii, K. V.; Goldich, A. S.

    2014-08-01

    Mathematical models and results of calculation of plasma equilibrium in a circular cylinder with three helical or straight imbedded current-carrying conductors (i.e., in a straightened analog of a toroidal Galathea trap) are presented. The equilibrium is described in the framework of two-dimensional boundary value problems with plane and helical analogs of the Grad-Shafranov equation for the scalar magnetic flux function. Problems with first-kind boundary conditions corresponding to a magnetically transparent boundary of the cylinder and problems with second-kind boundary conditions and a given value of the electric current flowing in plasma (in addition to those flowing in the conductors) are considered. Deformations of magnetoplasma configurations in the cylinder for different formulations of the above-specified problems are investigated numerically.

  18. Rotating fiber array molecular driver and molecular momentum transfer device constructed therewith

    DOEpatents

    Milleron, Norman

    1983-01-01

    A rotating fiber array molecular driver is disclosed which includes a magnetically suspended and rotated central hub to which is attached a plurality of elongated fibers extending radially therefrom. The hub is rotated so as to straighten and axially extend the fibers and to provide the fibers with a tip speed which exceeds the average molecular velocity of fluid molecules entering between the fibers. Molecules colliding with the sides of the rotating fibers are accelerated to the tip speed of the fiber and given a momentum having a directional orientation within a relatively narrow distribution angle at a point radially outward of the hub, which is centered and peaks at the normal to the fiber sides in the direction of fiber rotation. The rotating fiber array may be used with other like fiber arrays or with other stationary structures to form molecular momentum transfer devices such as vacuum pumps, molecular separators, molecular coaters, or molecular reactors.

  19. Effects of screens set characteristics on the flow field in a wind tunnel

    NASA Astrophysics Data System (ADS)

    Santos, A. M.; Souza, D. B.; Costa, F. O.; Farias, M. H.; Massari, P. de L.; Araújo, S.; Zanirath, Y. B.

    2016-07-01

    Wind tunnels have broad range of applications, and although there are common elements among the different types of tunnels, the layout and configuration of each facility will depend on its particular purpose. The flow conditioners section is a common component for all tunnels, and frequently contains flow straighteners and screens [1]. The role of screens is to minimize non uniformities or turbulence level on the flow field. In this work, the development and characteristics of the vertical velocity profile along an atmospheric wind tunnel length were evaluated. By using such data as initial reference, the effects, on the flow, when screens set is inserted on it were analyzed, in order to identify which changes could be done in the wind tunnel configuration to improve the characteristics of the flow field. Such atmospheric wind tunnel is a facility which belongs to the Brazilian National Metrology Institute INMETRO.

  20. Histology of the mucosa of the oesophagogastric junction and the stomach in adult Rana perezi.

    PubMed Central

    Gallego-Huidobro, J; Pastor, L M

    1996-01-01

    The histological structure of the frog digestive mucosa changes at the oesophagogastric junction. The pseudostratified ciliated mucosal epithelium of oesophageal type changes to a simple mucus-secreting epithelium of gastric type. The glands straighten and the muscularis mucosae develops as a complete layer. The muscularis increases in thickness. Unlike the mammalian stomach, in the frog the surface of the plicae forms convoluted ridges that delimit furrow-shaped pits. Two types of gastric glands are distinguished, fundal and pyloric. The former consist of mucous, oxynticopeptic and endocrine cells. The pyloric glandular cells are mainly of mucus-secreting type with scattered endocrine cells. Scattered endocrine cells of P, D, G, A, EC, and EC-L-like types are found in the glands along the stomach. It is concluded that the mucosal structure of the anuran oesophagogastric junction and stomach is less complicated than that of mammals, including man. Images Fig. 1 Fig. 2 PMID:8621343

  1. Reduction of Springback of Sheet Metals by Bottoming

    NASA Astrophysics Data System (ADS)

    Ogawa, Takayuki; Hirahara, Atsushi; Yoshida, Fusahito

    2010-06-01

    The effect of bottoming on the reduction of springback is investigated by performing V-air-bending experiment on a high strength steel sheet of TS590MPa and the corresponding FE simulation. From the experiment, it was found that the springback is drastically decreased with increasing bottoming force. This is mainly due to the reduction of bending moment by compressive load acting normally to the sheet. At an early stage of bottoming, springback is also influenced by the change of geometrical rigidity of the bent sheet due to the straightening of ridge line warp. Since bottoming is a process of reverse deformation of tension-compression, the Bauschinger effect of materials should be taken into account for its accurate numerical simulation. 3D FE simulation using Yoshida-Uemori kinematic hardening model predicts well the bottoming effect.

  2. Laser reshaping of nasal septum cartilage: clinical results for 40 patients

    NASA Astrophysics Data System (ADS)

    Sobol, Emil N.; Sviridov, Alexander P.; Bagratashvili, Victor N.; Omelchenko, Alexander I.; Ovchinnikov, Yuriy M.; Shekhter, Anatoliy B.; Svistushkin, Valeriy M.; Shinaev, Alexander N.

    2000-05-01

    Clinical results on sparing laser reshaping of nasal septum cartilage are reported for the first time. Forty patients have been treated with holmium laser to correct a deformed cartilage. The laser reshaping is a bloodless, painless procedure which takes few minutes to straighten nasal septum. The stability of the new shape and possible side effects have been examined during twelve months. The headache and other negative symptoms have disappeared, as a result of laser treatment for the most of patients. Rhinoscopic examination show an excellent long-term reshaping effects for nasal septum of 23 patients, and, also, good results for other 12 patients. For 5 patients only a little effect takes place. Our rhinomanometric examinations demonstrate a pronounced improvement of the breathing for 35 patients. No visible undesirable side effects were observed for all patients underwent to laser reshaping procedure.

  3. Aluminum alloy 6013 sheet for new U.S. Navy aircraft

    NASA Astrophysics Data System (ADS)

    Kaneko, R. S.; Bakow, L.; Lee, E. W.

    1990-05-01

    The recently developed aluminum alloy 6013-T6 has been selected for the fuselage skin and other applications on the U.S. Navy's P-7A airplane, in place of the traditional 2024-T3 clad sheet. Alloy 6013-T6 is naturally corrosion resistant, like the well-established alloy 6061, and hence is used unclad. Its fatigue strength, fatigue crack growth and fracture toughness compare favorably with 2024-T3. Replacement of alloy 2024 with alloy 6013 also reduces manufacturing costs for formed parts, because 6013 is readily formed in the T4 temper, then simply aged to T6, thus avoiding the costly heat treatments and straightening required for alloy 2024.

  4. Algebro-geometric solutions to the modified Sawada-Kotera hierarchy

    NASA Astrophysics Data System (ADS)

    Wu, Lihua; He, Guoliang; Geng, Xianguo

    2012-12-01

    Based on solving the Lenard recursion equation and the zero-curvature equation, we derive the modified Sawada-Kotera (SK) hierarchy associated with a 3 × 3 matrix spectral problem. Resorting to the characteristic polynomial of Lax matrix for the modified SK hierarchy, we introduce a trigonal curve K_{m-1} and present the corresponding Baker-Akhiezer function and meromorphic function on it. The Abel map is introduced to straighten out the modified SK flows. With the aid of the property of the Baker-Akhiezer function and the meromorphic function and their asymptotic expansions, we arrive at their explicit Riemann theta function representations. Algebro-geometric solutions of the entire modified SK hierarchy are obtained by using asymptotic expansion of the meromorphic function and its Riemann theta function representation. As an application, we give two simple examples.

  5. Quasi-periodic Solutions of the Kaup-Kupershmidt Hierarchy

    NASA Astrophysics Data System (ADS)

    Geng, Xianguo; Wu, Lihua; He, Guoliang

    2013-08-01

    Based on solving the Lenard recursion equations and the zero-curvature equation, we derive the Kaup-Kupershmidt hierarchy associated with a 3×3 matrix spectral problem. Resorting to the characteristic polynomial of the Lax matrix for the Kaup-Kupershmidt hierarchy, we introduce a trigonal curve {K}_{m-1} and present the corresponding Baker-Akhiezer function and meromorphic function on it. The Abel map is introduced to straighten out the Kaup-Kupershmidt flows. With the aid of the properties of the Baker-Akhiezer function and the meromorphic function and their asymptotic expansions, we arrive at their explicit Riemann theta function representations. The Riemann-Jacobi inversion problem is achieved by comparing the asymptotic expansion of the Baker-Akhiezer function and its Riemann theta function representation, from which quasi-periodic solutions of the entire Kaup-Kupershmidt hierarchy are obtained in terms of the Riemann theta functions.

  6. Spines of Steel: A Case of Surgical Enthusiasm in Cold War America.

    PubMed

    Linker, Beth

    2016-01-01

    Just as the prevalence of scoliosis began to decline precipitously after World War II, American orthopedic surgeon Dr. Paul R. Harrington devised a new, invasive surgical system whereby implantable prosthetic metal rods and hooks were used to straighten curved backs. By the 1970s, "Harrington rods" had become the gold standard of surgical scoliosis care in the United States, replacing more conventional methods of exercise, bracing, and casting. This article situates the success of Harrington rods within a much larger and historically longer debate about why, when compared to those in other nations, American surgeons appear to be "more aggressive" and "knife-happy." Using Harrington's papers and correspondence, I argue that patients played a vital role in the rise of spinal surgery. As such, this article examines not only how surgical enthusiasm has been historically measured, defined, and morally evaluated, but also how scoliosis became classified as a debility in need of surgical management. PMID:27374847

  7. Equations determine coiled tubing collapse pressure

    SciTech Connect

    Avakov, V.; Taliaferro, W.

    1995-07-24

    A set of equations has been developed for calculating pipe collapse pressure for oval tubing such as coiled tubing. When coiled tubing is placed onto a reel, the tubing is forced into an oval shape and never again returns to perfect roundness because the coiling process exceeds the plasticity limits of the tubing. Straightening the tubing for the trip into the well does not restore roundness. The consequence of this physical property is that all coiled tubing collapse pressure calculations should be made considering oval tubing, not round tubing. Tubing collapse can occur when formation pressure against the coiled tubing exceeds the collapse resistance inherent in the coiled tubing. As coiled tubing becomes more oval in shape, it becomes more oval in shape, it becomes more susceptible to collapse from outside pressure.

  8. Mechanical characteristics of novel polyester/NiTi wires braided composite stent for the medical application

    NASA Astrophysics Data System (ADS)

    Zou, Qiuhua; Xue, Wen; Lin, Jing; Fu, Yijun; Guan, Guoping; Wang, Fujun; Wang, Lu

    Stents have been widely used in percutaneous surgery to treat stenosis diseases. The braided NiTi stent, as a promising prototype, still has limitations of low radial force and loose structure. In the present study, a newly integrated composite stent was designed and braided with NiTi wires and polyester multifilament yarns by textile technology. The mechanical properties of four composite stents and the control bare NiTi stent were evaluated by in vitro compression, bending and anti-torsion tests. The results showed that integrated polyester/NiTi composite stents were superior in radial support. The stents could keep patency even when highly curved and had lower stent straightening force. Composite stents with certain structure stayed stable under twisting. The configuration of NiTi wires in composite stents could significantly impact stent deformation under twisting.

  9. Filters for cathodic arc plasmas

    DOEpatents

    Anders, Andre; MacGill, Robert A.; Bilek, Marcela M. M.; Brown, Ian G.

    2002-01-01

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  10. Structural dynamics of an actin spring.

    PubMed

    Mahadevan, L; Riera, C S; Shin, Jennifer H

    2011-02-16

    Actin-based motility in cells is usually associated with either polymerization/depolymerization in the presence of cross-linkers or contractility in the presence of myosin motors. Here, we focus on a third distinct mechanism involving actin in motility, seen in the dynamics of an active actin spring that powers the acrosomal reaction of the horseshoe crab (Limulus polyphemus) sperm. During this process, a 60-μm bent and twisted bundle of cross-linked actin uncoils and becomes straight in a few seconds in the presence of Ca(2+). This straightening, which occurs at a constant velocity, allows the acrosome to forcefully penetrate the egg. Synthesizing ultrastructural information with the kinetics, energetics, and imaging of calcium binding allows us to construct a dynamical theory for this mechanochemical engine consistent with our experimental observations. It also illuminates the general mechanism by which energy may be stored in conformational changes and released cooperatively in ordered macromolecular assemblies. PMID:21320427

  11. Automatic Upright Adjustment of Photographs With Robust Camera Calibration.

    PubMed

    Lee, Hyunjoon; Shechtman, Eli; Wang, Jue; Lee, Seungyong

    2014-05-01

    Man-made structures often appear to be distorted in photos captured by casual photographers, as the scene layout often conflicts with how it is expected by human perception. In this paper, we propose an automatic approach for straightening up slanted man-made structures in an input image to improve its perceptual quality. We call this type of correction upright adjustment. We propose a set of criteria for upright adjustment based on human perception studies, and develop an optimization framework which yields an optimal homography for adjustment. We also develop a new optimization-based camera calibration method that performs favorably to previous methods and allows the proposed system to work reliably for a wide range of images. The effectiveness of our system is demonstrated by both quantitative comparisons and qualitative user study. PMID:26353220

  12. Ridge network in crumpled paper.

    PubMed

    Andresen, Christian André; Hansen, Alex; Schmittbuhl, Jean

    2007-08-01

    The network formed by ridges in a straightened sheet of crumpled paper is studied using a laser profilometer. Square sheets of paper were crumpled into balls, unfolded, and their height profile measured. From these profiles the imposed ridges were extracted as networks. Nodes were defined as intersections between ridges, and links as the various ridges connecting the nodes. Many network and spatial properties have been investigated. The tail of the ridge length distribution was found to follow a power law, whereas the shorter ridges followed a log-normal distribution. The degree distribution was found to have an exponentially decaying tail, and the degree correlation was found to be disassortative. The facets created by the ridges and the Voronoi diagram formed by the nodes have also been investigated. PMID:17930105

  13. Twist- and tension-mediated elastic coupling between DNA-binding proteins.

    PubMed

    Koslover, Elena F; Spakowitz, Andrew J

    2009-05-01

    We study the effective interaction between DNA-binding proteins that arises from elastic stresses in the DNA when tension is applied. Using the wormlike chain model, we calculate the free energy cost of introducing multiple nearby bends in the DNA. We find that the bend deformation energy promotes aggregation to straighten the linker DNA, while twist resistance of the linker leads to damped oscillations in the coupling free energy between two proteins. We calculate the mean first encounter time for proteins sliding along DNA, indicating, in some cases, an optimal applied tension for protein assembly. Our results highlight the need to consider DNA twist even when no torsion is applied and the DNA ends are free to rotate. The variable-range oscillatory coupling between DNA-binding proteins may provide a versatile mechanism for tension-mediated gene regulation. PMID:19518837

  14. Twist- and Tension-Mediated Elastic Coupling between DNA-Binding Proteins

    NASA Astrophysics Data System (ADS)

    Koslover, Elena F.; Spakowitz, Andrew J.

    2009-05-01

    We study the effective interaction between DNA-binding proteins that arises from elastic stresses in the DNA when tension is applied. Using the wormlike chain model, we calculate the free energy cost of introducing multiple nearby bends in the DNA. We find that the bend deformation energy promotes aggregation to straighten the linker DNA, while twist resistance of the linker leads to damped oscillations in the coupling free energy between two proteins. We calculate the mean first encounter time for proteins sliding along DNA, indicating, in some cases, an optimal applied tension for protein assembly. Our results highlight the need to consider DNA twist even when no torsion is applied and the DNA ends are free to rotate. The variable-range oscillatory coupling between DNA-binding proteins may provide a versatile mechanism for tension-mediated gene regulation.

  15. Fabrication of highly conductive carbon nanotube fibers for electrical application

    NASA Astrophysics Data System (ADS)

    Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

    2015-09-01

    Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 106 s m-1. The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers.

  16. Black women's hair: the main scalp dermatoses and aesthetic practices in women of African ethnicity *

    PubMed Central

    Tanus, Aline; Oliveira, Camila Caberlon Cruz; Villarreal, Delky Johanna Villarreal; Sanchez, Fernando Andres Vargas; Dias, Maria Fernanda Reis Gavazzoni

    2015-01-01

    Afro-ethnic hair is different from Caucasian and Asian hair and has unique features. Ethnic hair is more prone to certain conditions or diseases. Such diseases are not only related to the fragile inner structure of the hair, but also to the cultural habits of hairstyles that often exert traction forces upon the pilosebaceous follicle. Women with African hair subject their hair to chemical treatments such as hair straightening and relaxing, and thus modify the structure of their hair shaft, making it more susceptible to damage. For this reason, hair complaints are common among black women and represent a diagnostic challenge to the dermatologist, requiring a thorough clinical examination of the hair and scalp, and a detailed medical history of the patient. The purpose of this review is to warn of the potential side effects and sequelae related to hairstyles and hair treatments used by black women, and to highlight the major diseases that affect this ethnicity. PMID:26375213

  17. On the tear resistance of skin

    SciTech Connect

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-03-27

    Tear resistance is vitally important for the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. Here we explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. Finally, we express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.

  18. High septal osteotomy in rhinoplasty for the deviated nose.

    PubMed

    Jameson, John J; Perry, Adam D; Ritter, Edmond F

    2006-01-01

    When attempting to straighten a patient's healed, deviated bony nasal dorsum, deviation of the central structure (high dorsal septum and medial nasal bones) must be addressed following the completion of medial and lateral osteotomies. When hump resection is not performed, blunt fracture (digitally or with forceps) of the deviated central structure is not a reliable method of mobilization, often leading to postoperative nasal drift. An intranasal osteotomy technique to mobilize the central structure of the nose is described, called "high septal osteotomy." Review of 25 cases suggests high septal osteotomy, supplemented as needed by resection of overlapping septal elements, can be performed safely and efficaciously, permitting stable midline reduction of the nasal pyramid. The technique is not advocated when hump resection is performed, as it is unnecessary and could destabilize the dorsum. Even aggressive maneuvers to mobilize the bony dorsum may fail if not performed properly with meticulous attention to completion of all osteotomies. PMID:16374094

  19. Probabilistic constitutive law for damage in ligaments.

    PubMed

    Guo, Zheying; De Vita, Raffaella

    2009-11-01

    A new constitutive equation is presented to describe the damage evolution process in parallel-fibered collagenous tissues such as ligaments. The model is formulated by accounting for the fibrous structure of the tissues. The tissue's stress is defined as the average of the collagen fiber's stresses. The fibers are assumed to be undulated and straightened out at different stretches that are randomly defined according to a Weibull distribution. After becoming straight, each collagen fiber is assumed to be linear elastic. Damage is defined as a reduction in collagen fiber's stiffness and occurs at different stretches that are also randomly defined by a Weibull distribution. Due to the lack of experimental data, the predictions of the constitutive equation are analyzed by varying the values of its structural parameters. Moreover, the results are compared with the available stress-strain data in the biomechanics literature that evaluate damage produced by subfailure stretches in rat medial collateral ligaments. PMID:19665914

  20. Direct contact, binary fluid geothermal boiler

    DOEpatents

    Rapier, P.M.

    1979-12-27

    Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carryover through the turbine causing corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

  1. Direct contact, binary fluid geothermal boiler

    DOEpatents

    Rapier, Pascal M.

    1982-01-01

    Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carry-over through the turbine causes corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

  2. Turbulence and mechanism of resistance on spheres and cylinders

    NASA Technical Reports Server (NTRS)

    Ahlborn, FR

    1932-01-01

    The nature of turbulent flow through pipes and around obstacles is analyzed and illustrated by photographs of turbulence on screens and straighteners. It is shown that the reversal of flow and of the resistance law on spheres is not explainable by Prandtl's turbulence in the boundary layer. The investigation of the analogous phenomena on the cylinder yields a reversal of the total field of flow. The very pronounced changes in pressure distribution connected with it were affirmed by manometric measurements on spheres by Professor O. Krell. The reversal in a homogenous nonvortical flow is brought about by the advance of the stable arrangement of Karman's dead air vortices toward the test object and by the substitution of an alternatingly one-sided or rotating but stable vortex formation in place of the initially symmetrical formation. This also explains the marked variations of the models.

  3. On the tear resistance of skin

    NASA Astrophysics Data System (ADS)

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-03-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.

  4. On the tear resistance of skin

    PubMed Central

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-01-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip. PMID:25812485

  5. Using Modelica to investigate the dynamic behaviour of the German national standard for high pressure natural gas flow metering

    NASA Astrophysics Data System (ADS)

    von der Heyde, M.; Schmitz, G.; Mickan, B.

    2016-08-01

    This paper presents a computational model written in Modelica for the high pressure piston prover (HPPP) used as the national primary standard for high pressure natural gas flow metering in Germany. With a piston prover the gas flow rate is determined by measuring the time a piston needs to displace a certain volume of gas in a cylinder. Fluctuating piston velocity during measurement can be a significant source of uncertainty if not considered in an appropriate way. The model was built to investigate measures for the reduction of this uncertainty. Validation shows a good compliance of the piston velocity in the model with measured data for certain volume flow rates. Reduction of the piston weight, variation of the start valve switching time and integration of a flow straightener were found to reduce the piston velocity fluctuations in the model significantly. The fast and cost effective generation of those results shows the strength of the used modelling approach.

  6. Fukushima Nuclear Accident: Sticking to the facts, not to the political correctness

    NASA Astrophysics Data System (ADS)

    Ohska, Tokio

    2014-05-01

    The Fukushima Nuclear Reactor disaster of 2011 is still a continuing disaster three years later, although some experts have proclaimed the 4 reactors being already under control. It is surely an incredibly difficult task to properly terminate nuclear accidents. However, I should point out that the process of termination plan has been marred by too much of politics and business messing up a scientific approach to do it in a rational way. This blame must to go to both pro-nuclear and anti-nuclear power people. It makes me feel sad to see people not respecting science in executing such a difficult task. I shall list up where things went wrong with the hope that this kind of action, as I do here, would trigger people to get back to science to straighten out the execution process. I will show a few examples of published papers presenting the opinion that it is inappropriate what the Japanese government considers to be safe.

  7. Oblique septal crossbar graft for anterior septal angle reconstruction.

    PubMed

    Aziz, Zeeshan S; Brenner, Michael J; Putman, Harrison C

    2010-01-01

    Nasal septal deformity is a central feature of the crooked nose, contributing to functional and aesthetic problems. Straightening of the septum often requires resection, scoring, or incision of the septum--maneuvers that inevitably weaken the cartilaginous dorsal and caudal L-shaped struts, which together are known as the L-strut. Compromise of this L-strut predisposes to septal buckling, recurrent deviation, and saddle nose deformity. We describe our experience with the oblique septal crossbar, a structural graft that allows biomechanically sound anterior septal angle reconstruction during septorhinoplasty. The technique improves dorsal septal support and facilitates correction of the crooked nose. The open septorhinoplasty approach and swinging door maneuver are followed by placement of a diagonally oriented crossbar graft, obtained from cartilage or the perpendicular plate. The approach allows consistent midline correction and buttressing of the nasal dorsum, with no complications to date. PMID:21079121

  8. [The crooked nose: correction of dorsal and caudal septal deviations].

    PubMed

    Foda, H M T

    2010-09-01

    The deviated nose represents a complex cosmetic and functional problem. Septal surgery plays a central role in the successful management of the externally deviated nose. This study included 800 patients seeking rhinoplasty to correct external nasal deviations; 71% of these suffered from variable degrees of nasal obstruction. Septal surgery was necessary in 736 (92%) patients, not only to improve breathing, but also to achieve a straight, symmetric external nose. A graduated surgical approach was adopted to allow correction of the dorsal and caudal deviations of the nasal septum without weakening its structural support to the nasal dorsum or nasal tip. The approach depended on full mobilization of deviated cartilage, followed by straightening of the cartilage and its fixation in the corrected position by using bony splinting grafts through an external rhinoplasty approach. PMID:20809379

  9. Molecular Order of Arterial Collagen Using Circular Polarization Second-Harmonic Generation Imaging.

    PubMed

    Turcotte, Raphaël; Mattson, Jeffrey M; Wu, Juwell W; Zhang, Yanhang; Lin, Charles P

    2016-02-01

    Second-harmonic generation (SHG) originates from the interaction between upconverted fields from individual scatterers. This renders SHG microscopy highly sensitive to molecular distribution. Here, we aim to take advantage of the difference in SHG between aligned and partially aligned molecules to probe the degree of molecular order during biomechanical testing, independently of the absolute orientation of the scattering molecules. Toward this goal, we implemented a circular polarization SHG imaging approach and used it to quantify the intensity change associated with collagen fibers straightening in the arterial wall during mechanical stretching. We were able to observe the delayed alignment of collagen fibers during mechanical loading, thus demonstrating a simple method to characterize molecular distribution using intensity information alone. PMID:26806883

  10. Polarization-resolved SHG microscopy of rat-tail tendon with controlled mechanical strain

    NASA Astrophysics Data System (ADS)

    Gusachenko, I.; Goulam Houssen, Y.; Tran, V.; Allain, J.-M.; Schanne-Klein, M.-C.

    2013-06-01

    We combined polarization-resolved SHG microscopy with mechanical assays in rat-tail-tendon and measured collagen remodeling upon controlled stretching. This approach aimed to analyze the relationship between macroscopic response and sub-micrometer scale organization of collagen fibrils. We observed a straightening of the crimps followed by a sliding of the fibrils with increasing stretching of the tendon fascicles. Polarization resolution of the SHG images provided complementary information about the orientation dispersion of collagen fibrils within the focal volume and enabled monitoring of collagen remodeling at the sub-micrometer scale. Our approach can be readily generalized to other tissues and should bring new valuable information about biomechanics of microstructured tissues.

  11. A new ultrasonic canal preparation system with electronic monitoring of file tip position.

    PubMed

    Kobayashi, C; Yoshioka, T; Suda, H

    1996-09-01

    A new ultrasonic root canal preparation system has been developed that electronically monitors the location of the file tip during all instrumentation procedures. The Root ZX has been adapted for this purpose, and its filter circuit effectively cuts out the large spike noise of the ultrasonic unit. During enlargement of the canal, the ultrasonic vibration of the file can be stopped at any desired position on the meter. Extracted human tooth models with electronically measurable canals were used to test the device. Pre- and postoperative shapes of the root canals were evaluated using contact microradiography. The autostop mechanism worked correctly. Using a weak power and fine files, straightening, ledge formation, and file breakage were minimal. It seems that this system minimized the danger of overinstrumentation and could be safely applied in clinical practice. PMID:9198433

  12. The role of septal surgery in management of the deviated nose.

    PubMed

    Foda, Hossam M T

    2005-02-01

    The deviated nose represents a complex cosmetic and functional problem. Septal surgery plays a central role in the successful management of the externally deviated nose. This study included 260 patients seeking rhinoplasty to correct external nasal deviations; 75 percent of them had various degrees of nasal obstruction. Septal surgery was necessary in 232 patients (89 percent), not only to improve breathing but also to achieve a straight, symmetrical, external nose as well. A graduated surgical approach was adopted to allow correction of the dorsal and caudal deviations of the nasal septum without weakening its structural support to the dorsum or nasal tip. The approach depended on full mobilization of deviated cartilage, followed by straightening of the cartilage and its fixation in the corrected position by using bony splinting grafts through an external rhinoplasty approach. PMID:15692343

  13. Penile prosthesis implant with bi-triangular excision and graft for surgical therapy of Peyronie's disease: A case report.

    PubMed

    de Freitas Miranda, Alexandre; Lopes Cançado Machado, Bruno

    2015-12-01

    We present a case of a 65-year-old man, who presented with moderate erectile dysfunction and a dorsal penile deviation of 60° caused by Peyronie's disease. The patient underwent bi-triangularshaped plaque excision, followed by grafting and implantation of inflatable penile prosthesis. Complete penile straightening, without mechanical or geometric abnormalities, was achieved using bi-triangular excision and grafting. Postoperatively, the patient reported high satisfaction with the results and could perform sexual intercourse naturally. This novel technique corrects any degree of penile curvature, permits malleable and semi-rigid penile prosthesis implantation, avoids penile length loss, and eliminates additional incisions. To our knowledge, this case is the first in the literature in which the bi-triangular technique was successfully used for penile prosthesis implantation secondary to Peyronie's disease. This new technique appears to be a good solution to correct penile curvature during penile prosthesis implantation for the treatment of Peyronie's disease associated with erectile dysfunction. PMID:26766812

  14. A review of surgical strategies for penile prosthesis implantation in patients with Peyronie’s disease

    PubMed Central

    Anaissie, James

    2016-01-01

    The introduction of the inflatable penile prosthesis (IPP) has revolutionized the treatment of patients with both Peyronie’s disease (PD) and erectile dysfunction (ED). A thorough literature review was performed in order to review the surgical strategies used to treat PD, using the PubMed online database with the keywords “penile prosthesis”, “surgical management” and “Peyronie’s disease”. Patient satisfaction rates of 72–100% and partner satisfaction rates of 89% have been reported in the literature, although strong preoperative education may be needed to prepare patients for risks such as penile shortening, seen in up to 54% of patients. Three-piece IPPs are most commonly used, and when comparing the two most popular models (AMS 700 CX vs. Coloplast Titan), no significant differences were seen in functional outcomes or patient satisfaction. Simple insertion of an IPP has been shown to resolve curvature in 33–90% of patients, but surgeons may often need to also utilize ancillary straightening procedures for residual curvatures. Manual modeling can correct residual curvature with an 86–100% success rate, but with a 4% risk of urethral injury. When the post-modeling residual curvature exceeds 30 degrees, a plaque-releasing incision or plication is recommended to further reduce curvature. Grafting is recommended if the resulting incisional defect is larger than two centimeters. Alternative straightening techniques such as plication prior to IPP insertion, endoscopic plaque resection, the “scratch technique” and bone saw plaque incision have also been described. PMID:27298781

  15. The effects of water on heat-styling damage.

    PubMed

    Christian, Paul; Winsey, Nigel; Whatmough, Marie; Cornwell, Paul A

    2011-01-01

    Heated styling appliances, such as straightening irons, have grown in popularity in recent years, as have hair products such as heat-protection sprays. In this study we investigate whether the water in a heat-protection spray can affect the level of damage caused by heat styling. Tryptophan damage from heat styling was measured using fluorescence spectroscopy, and structural damage was investigated using light microscopy and single-fiber tensile testing. Hair samples were heat treated with straightening irons, following treatment with either a water-based, "wet," heat-protection spray or an ethanol-based, "dry," spray. Results showed that, as expected, tryptophan damage was reduced by repeated applications of both the "wet" and "dry" heat-protection sprays. However, no differences were seen between the "wet" versus the "dry" product. Light microscopy studies showed greater structural damage to hair treated with water and the "wet" spray. Tensile tests confirmed that there was greater damage to hair treated with the "wet" spray. Decreases in Young's modulus were greater in the presence of the "wet" spray. The results of this study suggest that the type of damage caused by heat treatments is different in wet versus dry hair. In dry hair, thermal treatments cause chemical damage and some structural damage. However, in wet hair, thermal treatments cause the same chemical damage, but considerably more structural damage, which causes significant changes in the physical properties of the hair. It is likely that the rapid evaporation of water from the hair is the main causal factor. Our experiments suggest that the effectiveness of commercial heat-protection sprays can be improved by the removal of water and by the use of volatile ingredients, such as ethanol, as base solvents. PMID:21443842

  16. Influence of RCS on Al-3Mg and Al-3Mg-0.25Sc alloys

    NASA Astrophysics Data System (ADS)

    Bhovi, Prabhakar M.; Venkateswarlu, K.

    2016-02-01

    An influence of repetitive corrugation and straightening (RCS) was studied on Al-3Mg and Al-3Mg-0.25Sc alloys up to eight passes. Each pass consist of a corrugation and followed by straightening. This has resulted in introducing large plastic strain in sample, and thus led to formation of sub-micron grain sizes with high angle grain boundaries. These sub grain formation was eventually resulted in improved mechanical properties. The average grain size of Al-3Mg-0.25Sc alloy after 8 passes yielded to ∼0.6pm. Microhardness, strength properties were evaluated and it suggests that RCS was responsible for high hardness values as compared to the as cast samples. The microhardness values after RCS were 105 HV and 130 HV for Al-3Mg and Al-3Mg-0.25Sc alloys, respectively. Similarly, ∼ 40% improvement in tensile strength from 240 MPa to 370 MPa was observed for Al- 3Mg-0.25Sc alloy after RCS process.Al-3Mg and Al-3Mg-0.25Scalloys exhibited maximum strength of 220 MPa and 370 MPa, respectively. It is concluded that RCS process has a strong influence on Al- 3Mg and Al-3Mg-0.25Sc alloys for obtaining improved mechanical properties and grain refinement. In addition to RCS process and presence of AESc precipitates in Al-3Mg-0.25Sc alloy had a significant role in grain refinement and improved mechanical properties as compared to Al-3Mg alloy.

  17. A bi-hemispheric neuronal network model of the cerebellum with spontaneous climbing fiber firing produces asymmetrical motor learning during robot control.

    PubMed

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2014-01-01

    To acquire and maintain precise movement controls over a lifespan, changes in the physical and physiological characteristics of muscles must be compensated for adaptively. The cerebellum plays a crucial role in such adaptation. Changes in muscle characteristics are not always symmetrical. For example, it is unlikely that muscles that bend and straighten a joint will change to the same degree. Thus, different (i.e., asymmetrical) adaptation is required for bending and straightening motions. To date, little is known about the role of the cerebellum in asymmetrical adaptation. Here, we investigate the cerebellar mechanisms required for asymmetrical adaptation using a bi-hemispheric cerebellar neuronal network model (biCNN). The bi-hemispheric structure is inspired by the observation that lesioning one hemisphere reduces motor performance asymmetrically. The biCNN model was constructed to run in real-time and used to control an unstable two-wheeled balancing robot. The load of the robot and its environment were modified to create asymmetrical perturbations. Plasticity at parallel fiber-Purkinje cell synapses in the biCNN model was driven by error signal in the climbing fiber (cf) input. This cf input was configured to increase and decrease its firing rate from its spontaneous firing rate (approximately 1 Hz) with sensory errors in the preferred and non-preferred direction of each hemisphere, as demonstrated in the monkey cerebellum. Our results showed that asymmetrical conditions were successfully handled by the biCNN model, in contrast to a single hemisphere model or a classical non-adaptive proportional and derivative controller. Further, the spontaneous activity of the cf, while relatively small, was critical for balancing the contribution of each cerebellar hemisphere to the overall motor command sent to the robot. Eliminating the spontaneous activity compromised the asymmetrical learning capabilities of the biCNN model. Thus, we conclude that a bi

  18. Rotor Re-Design for the SSME Fuel Flowmeter

    NASA Technical Reports Server (NTRS)

    Marcu, Bogdan

    1999-01-01

    The present report describes the process of redesigning a new rotor for the SSME Fuel Flowmeter. The new design addresses the specific requirement of a lower rotor speed which would allow the SSME operation at 1 15% rated power level without reaching a blade excitation by the wakes behind the hexagonal flow straightener upstream at frequencies close to the blade natural frequency. A series of calculations combining fleet flowmeters test data, airfoil fluid dynamics and CFD simulations of flow patterns behind the flowmeter's hexagonal straightener has led to a blade twist design alpha = alpha (radius) targeting a kf constant of 0.8256. The kf constant relates the fuel volume flow to the flowmeter rotor speed, for this particular value 17685 GPM at 3650 RPM. Based on this angle distribution, two actual blade designs were developed. A first design using the same blade airfoil as the original design targeted the new kf value only. A second design using a variable blade chord length and airfoil relative thickness targeted simultaneously the new kf value and an optimum blade design destined to provide smooth and stable operation and a significant increase in the blade natural frequency associated with the first bending mode, such that a comfortable margin could be obtained at 115% RPL. The second design is a result of a concurrent engineering process, during which several iterations were made in order to achieve a targeted blade natural frequency associated with the first bending mode of 1300 Hz. Water flow tests preliminary results indicate a kf value of 0.8179 for the f-irst design, which is within 1% of the target value. The second design rotor shows a natural frequency associated with the first bending mode of 1308 Hz, and a water-flow calibration constant of kf 0.8169.

  19. Curved bones: An adaptation to habitual loading.

    PubMed

    Milne, Nick

    2016-10-21

    Why are long bones curved? It has long been considered a paradox that many long bones supporting mammalian bodies are curved, since this curvature results in the bone undergoing greater bending, with higher strains and so greater fracture risk under load. This study develops a theoretical model wherein the curvature is a response to bending strains imposed by the requirements of locomotion. In particular the radioulna of obligate quadrupeds is a lever operated by the triceps muscle, and the bending strains induced by the triceps muscle counter the bending resulting from longitudinal loads acting on the curved bone. Indeed the theoretical model reverses this logic and suggests that the curvature is itself a response to the predictable bending strains induced by the triceps muscle. This, in turn, results in anatomical arrangements of bone, muscle and tendon that create a simple physiological mechanism whereby the bone can resist the bending due to the action of triceps in supporting and moving the body. The model is illustrated by contrasting the behaviour of a finite element model of a llama radioulna to that of a straightened version of the same bone. The results show that longitudinal and flexor muscle forces produce bending strains that effectively counter strains due to the pull of the triceps muscle in the curved but not in the straightened model. It is concluded that the curvature of these and other curved bones adds resilience to the skeleton by acting as pre-stressed beams or strainable pre-buckled struts. It is also proposed that the cranial bending strains that result from triceps, acting on the lever that is the radioulna, can explain the development of the curvature of such bones. PMID:27444401

  20. A unifying model for planform straightness of ripples and dunes in air and water

    USGS Publications Warehouse

    Rubin, David M.

    2012-01-01

    Geologists, physicists, and mathematicians have studied ripples and dunes for more than a century, but despite considerable effort, no general model has been proposed to explain perhaps the most fundamental property of their morphology: why are some bedforms straight, continuous, parallel, and uniform in planform geometry (i.e. two-dimensional) whereas others are irregular (three-dimensional)? Here we argue that physical coupling along the crest of a bedform is required to produce straight crests and that along-crest flow and sand transport provide effective physical mechanisms for that coupling. Ripples and dunes with the straightest and most continuous crests include longitudinal and oblique dunes in unidirectional flows, wave ripples, dunes in reversing flows, wind ripples, and ripples migrating along a slope. At first glance, these bedforms appear quite different (ripples and dunes; air and water; transverse, oblique, and longitudinal orientations relative to the net sand-transport direction), but they all have one property in common: a process that increases the amount of along-crest sand transport (that lengthens and straightens their crests) relative to the across-crest transport (that makes them migrate and take the more typical and more three-dimensional planform geometry). In unidirectional flows that produce straight bedforms, along-crest transport of sand is caused by along-crest flow (non-transverse bedform orientation), gravitational transport along an inclined crest, or ballistic splash in air. Bedforms in reversing flows tend to be straighter than their unidirectional counterparts, because reverse transport across the bedform crest reduces the net across-crest transport (that causes the more typical irregular geometry) relative to the along-crest transport (that smoothes and straightens planform geometry).

  1. Man-induced channel adjustment in Tennessee streams

    USGS Publications Warehouse

    Robbins, C.H.; Simon, Andrew

    1983-01-01

    Channel modifications in Tennessee, particularly in the western part, have led to large-scale instabilities in the channelized rivers and may have contributed to several bridge failures. These modifications, together with land-use practices, led to downcutting, headward erosion, downstream aggradation, accelerated scour, and bank instabilities. Changes in gradient by channel straightening caused more severe channel response than did dredging or clearing. Large-scale changes continue to occur in all the channelized rivers: the Obion River, its forks, and the South Fork Forked Deer River. However, the non-channelized Hatchie River in west Tennessee not only withstood the natural stresses imposed by the wet years of 1973 to 1975 but continues to exhibit characteristics of stability. Water-surface slope, the primary dependent variable, proved to be a sensitive and descriptive parameter useful in determining channel adjustment. Adjustments to man-induced increases in channel-slope are described by inverse exponential functions of the basic form S=ae(-b(t)); where ' S ' is some function describing channel-slope, ' t ' is the number of years since completion of channel work, and ' a ' and ' b ' are coefficients. Response times for the attainment of ' equilibrium ' channel slopes are a function of the magnitude and extent of the imposed modifications. The adjusted profile gradients attained by the streams following channelization are similar to the predisturbed profile gradients, where no alteration to channel length was made. Where the channels were straightened by constructing cut-offs, thus shortening channel length, then slope adjustments (reduction) proceed past the predisturbed profile gradients, to new profiles with lower gradients. (USGS)

  2. Ex Vivo Comparison of Mtwo and RaCe Rotary File Systems in Root Canal Deviation: One File Only versus the Conventional Method

    PubMed Central

    Aminsobhani, Mohsen; Nozari, Solmaz

    2015-01-01

    Objectives: Cleaning and shaping of the root canal system is an important step in endodontic therapy. New instruments incorporate new preparation techniques that can improve the efficacy of cleaning and shaping. The aim of this study was to compare the efficacy of Mtwo and RaCe rotary file systems in straightening the canal curvature using only one file or the conventional method. Materials and Methods: Sixty mesial roots of extracted human mandibular molars were prepared by RaCe and Mtwo nickel-titanium (NiTi) rotary files using the conventional and only one rotary file methods. The working length was 18 mm and the curvatures of the root canals were between 15–45°. By superimposing x-ray images before and after the instrumentation, deviation of the canals was assessed using Adobe Photoshop CS3 software. Preparation time was recorded. Data were analyzed using three-way ANOVA and Tukey’s post hoc test. Results: There were no significant differences between RaCe and Mtwo or between the two root canal preparation methods in root canal deviation in buccolingual and mesiodistal radiographs (P>0.05). Changes of root canal curvature in >35° subgroups were significantly more than in other subgroups with smaller canal curvatures. Preparation time was shorter in one file only technique. Conclusion: According to the results, the two rotary systems and the two root canal preparation methods had equal efficacy in straightening the canals; but the preparation time was shorter in one file only group. PMID:26877736

  3. A bi-hemispheric neuronal network model of the cerebellum with spontaneous climbing fiber firing produces asymmetrical motor learning during robot control

    PubMed Central

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2014-01-01

    To acquire and maintain precise movement controls over a lifespan, changes in the physical and physiological characteristics of muscles must be compensated for adaptively. The cerebellum plays a crucial role in such adaptation. Changes in muscle characteristics are not always symmetrical. For example, it is unlikely that muscles that bend and straighten a joint will change to the same degree. Thus, different (i.e., asymmetrical) adaptation is required for bending and straightening motions. To date, little is known about the role of the cerebellum in asymmetrical adaptation. Here, we investigate the cerebellar mechanisms required for asymmetrical adaptation using a bi-hemispheric cerebellar neuronal network model (biCNN). The bi-hemispheric structure is inspired by the observation that lesioning one hemisphere reduces motor performance asymmetrically. The biCNN model was constructed to run in real-time and used to control an unstable two-wheeled balancing robot. The load of the robot and its environment were modified to create asymmetrical perturbations. Plasticity at parallel fiber-Purkinje cell synapses in the biCNN model was driven by error signal in the climbing fiber (cf) input. This cf input was configured to increase and decrease its firing rate from its spontaneous firing rate (approximately 1 Hz) with sensory errors in the preferred and non-preferred direction of each hemisphere, as demonstrated in the monkey cerebellum. Our results showed that asymmetrical conditions were successfully handled by the biCNN model, in contrast to a single hemisphere model or a classical non-adaptive proportional and derivative controller. Further, the spontaneous activity of the cf, while relatively small, was critical for balancing the contribution of each cerebellar hemisphere to the overall motor command sent to the robot. Eliminating the spontaneous activity compromised the asymmetrical learning capabilities of the biCNN model. Thus, we conclude that a bi

  4. Visualization and velocity measurement of unsteady flow in a gas generator using cold-flow technique

    NASA Astrophysics Data System (ADS)

    Kuppa, Subrahmanyam

    1990-08-01

    Modeling of internal flow fields with hot, compressible fluids and sometimes combustion using cold flow techniques is discussed. The flow in a gas generator was modeled using cold air. The experimental set up was designed and fabricated to simulate the unsteady flow with different configurations of inlet tubes. Tests were run for flow visualization and measurement of axial velocity at different frequencies ranging from 5 to 12 Hz. Flow visualization showed that the incoming flow was a complex jet flow confined to a cylindrical enclosure, while the outgoing flow resembled the venting of a pressurized vessel. The pictures show a complex flow pattern due to the angling of the jet towards the wall for the bent tube configurations and straightened flows with straight tube and other configurations with straighteners. Velocity measurements were made at an inlet Re of 8.1 x 10(exp 4) based on maximum velocity and inlet diameter. Phase averaged mean velocities were observed to be well defined during charging and diminished during venting inside the cylinder. For the straight tube inlet comparison with a steady flow measurement of sudden expansion flow showed a qualitative similarity of the mean axial velocity distribution and centerline velocity decay during the charging phases. For the bent tube inlet case the contour plots showed the flow tendency towards the wall. Two cells were seen in the contours for the 8 and 12 Hz cases. The deviation of the point of occurrence of maximum velocity in a radial profile was found to be about 6.5 degrees. Entrance velocity profiles showed symmetry for the straight tube inlet but were skewed for the bent tube inlet. Contour plots of the phase averaged axial turbulence intensity for bent tube cases showed higher values in the core and near the wall in the region of impingement. Axial turbulence intensity measured for the straight tube case showed features as observed in an axisymmetric sudden expansion flow.

  5. Development of a Methodology to Gather Seated Anthropometry in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

    2009-01-01

    The Constellation Program's Crew Exploration Vehicle (CEV) is required to accommodate the full population range of crewmembers according to the anthropometry requirements stated in the Human-Systems Integration Requirement (HSIR) document (CxP70024). Seated height is one of many critical dimensions of importance to the CEV designers in determining the optimum seat configuration in the vehicle. Changes in seated height may have a large impact to the design, accommodation, and safety of the crewmembers. Seated height can change due to elongation of the spine when crewmembers are exposed to microgravity. Spinal elongation is the straightening of the natural curvature of the spine and the expansion of inter-vertebral disks. This straightening occurs due to fluid shifts in the body and the lack of compressive forces on the spinal vertebrae. Previous studies have shown that as the natural curvature of the spine straightens, an increase in overall height of 3% of stature occurs which has been the basis of the current HSIR requirements. However due to variations in the torso/leg ratio and impact of soft tissue, data is nonexistent as to how spinal elongation specifically affects the measurement of seated height. In order to obtain this data, an experiment was designed to collect spinal elongation data while in a seated posture in microgravity. The purpose of this study was to provide quantitative data that represents the amount of change that occurs in seated height due to spinal elongation in microgravity environments. Given the schedule and budget constraints of ISS and Shuttle missions and the uniqueness of the problem, a methodology had to be developed to ensure that the seated height measurements were accurately collected. Therefore, simulated microgravity evaluations were conducted to test the methodology and procedures of the experiment. This evaluation obtained seat pan pressure and seated height data to a) ensure that the lap restraint provided sufficient

  6. Ultra-stretchable conductors based on buckled super-aligned carbon nanotube films

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Luo, Shu; Sun, Li; Wu, Yang; Jiang, Kaili; Li, Qunqing; Wang, Jiaping; Fan, Shoushan

    2015-05-01

    Ultra-stretchable conductors are fabricated by coating super-aligned carbon nanotube (SACNT) films on pre-strained polydimethylsiloxane (PDMS) substrates and forming buckled SACNT structures on PDMS after release of the pre-strain. The parallel SACNT/PDMS conductors demonstrate excellent stability with normalized resistance changes of only 4.1% under an applied strain as high as 200%. The SACNT/PDMS conductors prepared with cross-stacked SACNT films show even lower resistance variation. The parallel SACNT/PDMS conductors exhibit high durability with a resistance increase of less than 5% after 10 000 cycles at 150% strain. In situ microscopic observations demonstrate that the buckled SACNT structures are straightened during the stretching process with reversible morphology evolution and thus the continuous SACNT conductive network can be protected from fracture. Due to the excellent electrical and mechanical properties of SACNT films and the formation of the buckled structure, SACNT/PDMS films exhibit high stretchability and durability, possessing great potential for use as ultra-stretchable conductors for wearable electronics, sensors, and energy storage devices.Ultra-stretchable conductors are fabricated by coating super-aligned carbon nanotube (SACNT) films on pre-strained polydimethylsiloxane (PDMS) substrates and forming buckled SACNT structures on PDMS after release of the pre-strain. The parallel SACNT/PDMS conductors demonstrate excellent stability with normalized resistance changes of only 4.1% under an applied strain as high as 200%. The SACNT/PDMS conductors prepared with cross-stacked SACNT films show even lower resistance variation. The parallel SACNT/PDMS conductors exhibit high durability with a resistance increase of less than 5% after 10 000 cycles at 150% strain. In situ microscopic observations demonstrate that the buckled SACNT structures are straightened during the stretching process with reversible morphology evolution and thus the continuous

  7. The Effect of Acoustic Disturbances on the Operation of the Space Shuttle Main Engine Fuel Flowmeter

    NASA Technical Reports Server (NTRS)

    Marcu, Bogdan; Szabo, Roland; Dorney, Dan; Zoladz, Tom

    2007-01-01

    The Space Shuttle Main Engine (SSME) uses a turbine fuel flowmeter (FFM) in its Low Pressure Fuel Duct (LPFD) to measure liquid hydrogen flowrates during engine operation. The flowmeter is required to provide accurate and robust measurements of flow rates ranging from 10000 to 18000 GPM in an environment contaminated by duct vibration and duct internal acoustic disturbances. Errors exceeding 0.5% can have a significant impact on engine operation and mission completion. The accuracy of each sensor is monitored during hot-fire engine tests on the ground. Flow meters which do not meet requirements are not flown. Among other parameters, the device is screened for a specific behavior in which a small shift in the flow rate reading is registered during a period in which the actual fuel flow as measured by a facility meter does not change. Such behavior has been observed over the years for specific builds of the FFM and must be avoided or limited in magnitude in flight. Various analyses of the recorded data have been made prior to this report in an effort to understand the cause of the phenomenon; however, no conclusive cause for the shift in the instrument behavior has been found. The present report proposes an explanation of the phenomenon based on interactions between acoustic pressure disturbances in the duct and the wakes produced by the FFM flow straightener. Physical insight into the effects of acoustic plane wave disturbances was obtained using a simple analytical model. Based on that model, a series of three-dimensional unsteady viscous flow computational fluid dynamics (CFD) simulations were performed using the MSFC PHANTOM turbomachinery code. The code was customized to allow the FFM rotor speed to change at every time step according to the instantaneous fluid forces on the rotor, that, in turn, are affected by acoustic plane pressure waves propagating through the device. The results of the simulations show the variation in the rotation rate of the flowmeter

  8. Scanning electron microscopic characterization of healing and normal rat ligament microstructure under slack and loaded conditions.

    PubMed

    Hurschler, Christof; Provenzano, Paolo P; Vanderby, Ray

    2003-01-01

    The objective of this study was to observe and compare behavior of the collagen fiber microstructure in normal and healing ligaments, both in situ and ex vivo, in order to add insight into the structure-function relationship in normal and healing ligaments. Fifty-two ligaments from 26 male rats were investigated. Eleven animals underwent surgical transection of both medial collateral ligaments (MCLs) (22 ligaments), which were allowed to heal for a period of 2 weeks. An additional 15 animals (30 ligaments) were used as normals. Ligaments were placed into six groups: Slack (n = 6 control, n = 6 healing), Reference (n = 4 control, n = 4 healing), Loaded (n = 4 control, n = 4 healing), 15 degrees Flexion (n = 4 control, n = 4 healing), 120 degrees Flexion (n = 4 control, n = 4 healing), and Tissue Strain vs. Flexion Angle (n = 8 normals). All ligaments, except those in the Tissue Strain vs. Flexion Angle group, were prepared for scanning electron microscopy. Tissues were harvested, mounted in a load frame, and chemically fixed in one of five states: (1). slack, (2). reference (onset of loading), (3). loaded, (4). 15 degrees knee flexion, or (5). 120 degrees knee flexion. After fixation the tissues were prepared for electron microscopy (SEM). The micrographs from the slack, reference, and loaded groups show fiber straightening with loading in normal ligaments as well as in both scar and "retracted" regions of healing ligaments. Collagen fibers' diameter and crimp patterns were dramatically changed in the scar region of healing ligaments: Width decreased from 19.4 +/- 1.7 microm to 6.5 +/- 2.1 microm (p <.000001), period from 51.4 +/- 15.1 microm to 11.0 +/- 2.4 microm (p <.000001), and amplitude from 9.8 +/- 0.8 microm to 3.9 +/- 0.8 microm (p <.000001). Normal ligaments fixed in situ show wavy regions at 120 degrees but less so at 15 degrees flexion. Healing ligaments fixed in situ show regions of fiber waviness in the scar region at 120 degrees and also at 15 degrees

  9. Computerized detection of vertebral compression fractures on lateral chest radiographs: Preliminary results with a tool for early detection of osteoporosis

    SciTech Connect

    Kasai, Satoshi; Li Feng; Shiraishi, Junji; Li Qiang; Doi, Kunio

    2006-12-15

    Vertebral fracture (or vertebral deformity) is a very common outcome of osteoporosis, which is one of the major public health concerns in the world. Early detection of vertebral fractures is important because timely pharmacologic intervention can reduce the risk of subsequent additional fractures. Chest radiographs are used routinely for detection of lung and heart diseases, and vertebral fractures can be visible on lateral chest radiographs. However, investigators noted that about 50% of vertebral fractures visible on lateral chest radiographs were underdiagnosed or under-reported, even when the fractures were severe. Therefore, our goal was to develop a computerized method for detection of vertebral fractures on lateral chest radiographs in order to assist radiologists' image interpretation and thus allow the early diagnosis of osteoporosis. The cases used in this study were 20 patients with severe vertebral fractures and 118 patients without fractures, as confirmed by the consensus of two radiologists. Radiologists identified the locations of fractured vertebrae, and they provided morphometric data on the vertebral shape for evaluation of the accuracy of detecting vertebral end plates by computer. In our computerized method, a curved search area, which included a number of vertebral end plates, was first extracted automatically, and was straightened so that vertebral end plates became oriented horizontally. Edge candidates were enhanced by use of a horizontal line-enhancement filter in the straightened image, and a multiple thresholding technique, followed by feature analysis, was used for identification of the vertebral end plates. The height of each vertebra was determined from locations of identified vertebral end plates, and fractured vertebrae were detected by comparison of the measured vertebral height with the expected height. The sensitivity of our computerized method for detection of fracture cases was 95% (19/20), with 1.03 (139/135) false

  10. Use-Dependent Curvature Changes in the GlideRite® Reusable Intubation Stylet.

    PubMed

    Smith, Cameron R; Urdaneta, Felipe; Gravenstein, Nikolaus

    2016-05-15

    The Glidescope® is one of the most widely used video laryngoscopes in the market. It is often used with a purpose-built, reusable, "nonmalleable" stainless steel stylet, the GlideRite®. In this study, we investigated whether this stylet retains its original curvature with repeated use and sterilization. To evaluate the shape and curvature of the stylets, high-resolution digital photographs were made of 55 GlideRite stylets (5 new and 50 randomly selected from operating room stock) laid on a grid background and analyzed using Adobe Photoshop®. In a similar fashion, 1 new stylet was inserted into and removed 100 times from an endotracheal tube and photographed every 20 cycles to determine the impact of use on stylet shape. For the 5 new stylets, the handle-to-tip angle was very consistent (23.44° ± 1.04°). The stylets in clinical use varied widely in their configuration. For analysis, they were divided into 3 groups based on the handle-to-tip angle: ±1 SD of the new stylets, those with a shallower angle (straighter), and those with a steeper angle (more curved). The handle-to-tip angles were as follows: 23.07° ± 0.80° (±1 SD), 18.39° ± 2.59° (straighter), and 27.65° ± 2.73° (more curved). Analysis of variance showed that the new and ±1 SD groups were not significantly different, but both the straighter (P = 0.0002) and more curved (P = 0.0048) groups were significantly different from new. The repeated insertion and removal of a new stylet resulted in gradual straightening of the curve of the stylet from 22° at baseline to 19.2° after 100 insertion/removal cycles. Used GlideRite reusable stylets are not reliably equivalent to new ones in terms of their shape or curvature. Given that the repeated insertion and removal of a new stylet from an endotracheal tube resulted in their straightening, it is likely that clinical use has the same effect. Because many used stylets were actually more curved than the new ones, we hypothesize that practitioners

  11. Pulmonary vessel segmentation utilizing curved planar reformation and optimal path finding (CROP) in computed tomographic pulmonary angiography (CTPA) for CAD applications

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Kuriakose, Jean W.; Chughtai, Aamer; Wei, Jun; Hadjiiski, Lubomir M.; Guo, Yanhui; Patel, Smita; Kazerooni, Ella A.

    2012-03-01

    Vessel segmentation is a fundamental step in an automated pulmonary embolism (PE) detection system. The purpose of this study is to improve the segmentation scheme for pulmonary vessels affected by PE and other lung diseases. We have developed a multiscale hierarchical vessel enhancement and segmentation (MHES) method for pulmonary vessel tree extraction based on the analysis of eigenvalues of Hessian matrices. However, it is difficult to segment the pulmonary vessels accurately under suboptimal conditions, such as vessels occluded by PEs, surrounded by lymphoid tissues or lung diseases, and crossing with other vessels. In this study, we developed a new vessel refinement method utilizing curved planar reformation (CPR) technique combined with optimal path finding method (MHES-CROP). The MHES segmented vessels straightened in the CPR volume was refined using adaptive gray level thresholding where the local threshold was obtained from least-square estimation of a spline curve fitted to the gray levels of the vessel along the straightened volume. An optimal path finding method based on Dijkstra's algorithm was finally used to trace the correct path for the vessel of interest. Two and eight CTPA scans were randomly selected as training and test data sets, respectively. Forty volumes of interest (VOIs) containing "representative" vessels were manually segmented by a radiologist experienced in CTPA interpretation and used as reference standard. The results show that, for the 32 test VOIs, the average percentage volume error relative to the reference standard was improved from 32.9+/-10.2% using the MHES method to 9.9+/-7.9% using the MHES-CROP method. The accuracy of vessel segmentation was improved significantly (p<0.05). The intraclass correlation coefficient (ICC) of the segmented vessel volume between the automated segmentation and the reference standard was improved from 0.919 to 0.988. Quantitative comparison of the MHES method and the MHES-CROP method with the

  12. Peri- and intraarticular analgesia (PIA) superior to other procedures in TKA – review of literature and results of own RCT

    PubMed Central

    Beckmann, J.; Stathellis, A.; Fitz, W.; Köck, F.; Bauer, G.; Gebauer, M.; Schnurr, C.

    2016-01-01

    Background: TKA is a worldwide established surgery with periarticular infiltrations being scientifically funded is the superiority of in the perioperative setup of TKA nowadays. However, nerve blocks are still widely used as perioperative standard meaning possible analgesia beyond surger, but simultaneously with sensomotoric deficiency and resulting risk of fall as well as increased pain after removal of nerval catheters. Also a standard procedure is intubation which means immediate pain after awakening of patients with resulting need for sufficient oral, intravenous, intramuscular or subcutaneous analgesia. We present an actual review of the literature and an own RCT comparing infiltrations with nerve blocks, which to our best knowledge presents the first RCT combined with an additional continous part. Methods: Literature review (PubMed)Own RCT: 50 TKA were randomized and prospectively included. 25 patients received nerve blocks with a single ischiadicus block and a femoralis block with additional perineural catheter. 25 patients received periarticular infiltrations together with an intraarticular catheter (PIA). All catheters stayed for 4 days. Both groups received a laryngeal masc. Postoperative mobilisation, surgeon and type of prosthesis were the same in all patients. The following was evaluated pre- and postoperatively (first, third and sixth hour, first until sixth day): VAS, additional analgetics/ opioids, KSS score, knee function and ability to raise the straightened leg. Complications as infection, falls, DVT etc. were recorded. Results: Periarticular infiltrations are superior to other options in the perioperative setup of TKA which is clearly shown by literature (several studies including reviews) as well as the results of our own RCT: Pain occured in both groups, however, VAS, additional analgetics/ opioids and KSS score as well as the ability to raise the straightened leg were significantly better following PIA (p<0,01), with comparable knee function

  13. Nonuniform elasticity of titin in cardiac myocytes: a study using immunoelectron microscopy and cellular mechanics.

    PubMed Central

    Granzier, H; Helmes, M; Trombitás, K

    1996-01-01

    Titin (also known as connectin) is a muscle-specific giant protein found inside the sarcomere, spanning from the Z-line to the M-line. The I-band segment of titin is considered to function as a molecular spring that develops tension when sarcomeres are stretched (passive tension). Recent studies on skeletal muscle indicate that it is not the entire I-band segment of titin that behaves as a spring; some sections are inelastic and do not take part in the development of passive tension. To better understand the mechanism of passive tension development in the heart, where passive tension plays an essential role in the pumping function, we investigated titin's elastic segment in cardiac myocytes using structural and mechanical techniques. Single cardiac myocytes were stretched by various amounts and then immunolabeled and processed for electron microscopy in the stretched state. Monoclonal antibodies that recognize different titin epitopes were used, and the locations of the titin epitopes in the sarcomere were studied as a function of sarcomere length. We found that only a small region of the I-band segment of titin is elastic; its contour length is estimated at approximately 75 nm, which is only approximately 40% of the total I-band segment of titin. Passive tension measurements indicated that the fundamental determinant of how much passive tension the heart develops is the strain of titin's elastic segment. Furthermore, we found evidence that in sarcomeres that are slack (length, approximately 1.85 microns) the elastic titin segment is highly folded on top of itself. Based on the data, we propose a two-stage mechanism of passive tension development in the heart, in which, between sarcomere lengths of approximately 1.85 microns and approximately 2.0 microns, titin's elastic segment straightens and, at lengths longer than approximately 2.0 microns, the molecular domains that make up titin's elastic segment unravel. Sarcomere shortening to lengths below slack

  14. E-M shaped septal encircling with Medpor reconstruction on crooked noses: personal technique and postoperative results.

    PubMed

    Emsen, Ilteris Murat

    2008-01-01

    Correction of the crooked or deviated nose, a complex cosmetic and functional problem, is a challenge for the rhinoplasty surgeon. Although corrections using a wide range of surgical techniques to straighten the nose and maximize nasal function have been proposed, recurrence is very common because of cartilage memory and scar contracture. Therefore, to prevent recurrence and to maintain the correction of the septum, a stable, strong, and permanent support is needed with the ability to maintain its given shape after placement on one or both sides of the septum. For this purpose, the author planned to use a personally-shaped graft (EMSEN) with high-density porous polyethylene (Medpor, Porex Surgical Inc., Newnan, GA). In this study, the concept and technique of Medpor, composed of a nonresorbable alloplastic material for correction of the crooked nose, and the authors' experience using it, are presented. Currently, Medpor is readily available on the market as a thin plain sheet (0.85 x 38 x 50 mm) that can be cut to an appropriate size for our (EMSEN) grafts. Ingrowths of fibrous tissue inside and around Medpor stabilize the upper lateral cartilages and septum in their newly corrected position and maintain the corrected/straightened position. This material was used in 18 patients with crooked noses (7 with C-type and 11 with S-type noses). During a mean follow-up period of 20 months (range, 10-50 months), there were no complications, recurrences, or extrusions. Functional evaluation was performed using a visual analog scale before surgery and 6 months after surgery. Patients were asked to score their nasal breathing on a scale ranging from 0 to 100. The mean preoperative value was 17.78% +/- 1.23% (range, 15-25%), and the postoperative value was 86.67% +/- 1.21% (range, 80-95%). In conclusion, the use of EMSEN with Medpor grafts is a safe, effective, reliable, and permanent method for correction of the crooked nose. In the long term, the authors believe that EMSEN

  15. Design and analysis of rotor systems with multiple trailing edge flaps and resonant actuators

    NASA Astrophysics Data System (ADS)

    Kim, Jun-Sik

    The purpose of this thesis is to develop piezoelectric resonant actuation systems and new active control methods utilizing the multiple trailing-edge flaps' configuration for rotorcraft vibration suppression and blade loads control. An aeroelastic model is developed for a composite rotor blade with multiple trailing-edge flaps. The rotor blade airloads are calculated using quasi-steady blade element aerodynamics with a free wake model for rotor inflow. A compressible unsteady aerodynamics model is employed to accurately predict the incremental trailing edge flap airloads. Both the finite wing effect and actuator saturation for trailing-edge flaps are also included in an aeroelastic analysis. For a composite articulated rotor, a new active blade loads control method is developed and tested numerically. The concept involves straightening the blade by introducing dual trailing edge flaps. The objective function, which includes vibratory hub loads, bending moment harmonics and active flap control inputs, is minimized by an integrated optimal control/optimization process. A numerical simulation is performed for the steady-state forward flight of an advance ratio of 0.35. It is demonstrated that through straightening the rotor blade, which mimics the behavior of a rigid blade, both the bending moments and vibratory hub loads can be significantly reduced by 32% and 57%, respectively. An active vibration control method is developed and analyzed for a hingeless rotor. The concept involves deflecting each individual trailing-edge flap using a compact resonant actuation system. Each resonant actuation system could yield high authority, while operating at a single frequency. Parametric studies are conducted to explore the finite wing effect of trailing-edge flaps and actuator saturation. A numerical simulation has been performed for the steady-state forward flight (mu = 0.15 ˜ 0.35). It is demonstrated that multiple trailing-edge flap configuration with the resonant actuation

  16. Three-dimensionality of field-induced magnetism in a high-temperature superconductor.

    PubMed

    Lake, B; Lefmann, K; Christensen, N B; Aeppli, G; McMorrow, D F; Ronnow, H M; Vorderwisch, P; Smeibidl, P; Mangkorntong, N; Sasagawa, T; Nohara, M; Takagi, H

    2005-09-01

    Many physical properties of high-temperature superconductors are two-dimensional phenomena derived from their square-planar CuO2 building blocks. This is especially true of the magnetism from the copper ions. As mobile charge carriers enter the CuO2 layers, the antiferromagnetism of the parent insulators, where each copper spin is antiparallel to its nearest neighbours, evolves into a fluctuating state where the spins show tendencies towards magnetic order of a longer periodicity. For certain charge-carrier densities, quantum fluctuations are sufficiently suppressed to yield static long-period order, and external magnetic fields also induce such order. Here we show that, in contrast to the chemically controlled order in superconducting samples, the field-induced order in these same samples is actually three-dimensional, implying significant magnetic linkage between the CuO2 planes. The results are important because they show that there are three-dimensional magnetic couplings that survive into the superconducting state, and coexist with the crucial inter-layer couplings responsible for three-dimensional superconductivity. Both types of coupling will straighten the vortex lines, implying that we have finally established a direct link between technical superconductivity, which requires zero electrical resistance in an applied magnetic field and depends on vortex dynamics, and the underlying antiferromagnetism of the cuprates. PMID:16100515

  17. Real space visualization of thermal fluctuations in a triangular flux-line lattice

    NASA Astrophysics Data System (ADS)

    Schwarz, A.; Liebmann, M.; Pi, U. H.; Wiesendanger, R.

    2010-03-01

    The temperature-dependent properties of a triangular flux-line lattice (FLL) in the low-flux density regime were investigated by evaluating the imaged flux-line (FL) size and the lattice regularity observed in real space utilizing magnetic force microscopy (MFM). At low temperatures, pinning by randomly distributed point defects in the anisotropic type-II superconductor Bi2Sr2CaCu2O8+δ results in curved FLs and lateral disorder within the FLL (Bragg glass). Above 30 K, depinning of pancake vortices (PVs) leads to straightening of FLs and a better-ordered lattice. Evaluation of the temperature-dependent imaged FL size allows us to determine the stiffness of the potential, in which FLs in the lattice are caged due to mutual repulsion between them. At 54.1 K, far below melting temperatures reported so far, thermal fluctuations plus the lateral force exerted by the scanning tip facilitate decoupling of PVs near the surface and the image contrast exhibit a liquid-like behavior. Our analysis demonstrates the ability of MFM to obtain three-dimensional information on the arrangement of PVs.

  18. Detection of short single-strand DNA homopolymers with ultrathin S i3N4 nanopores

    NASA Astrophysics Data System (ADS)

    Ma, Jian; Qiu, Yinghua; Yuan, Zhishan; Zhang, Yin; Sha, Jingjie; Liu, Lei; Sun, Litao; Ni, Zhonghua; Yi, Hong; Li, Deyu; Chen, Yunfei

    2015-08-01

    A series of nanopores with diameters ranging from 2.5 to 63 nm are fabricated on a reduced S i3N4 membrane by focused ion beam and high energy electron beam. Through measuring the blocked ionic currents for DNA strands threading linearly through those solid-state nanopores, it is found that the blockade ionic current is proportional to the square of the hydrodynamic diameter of the DNA strand. With the nanopore diameter reduced to be comparable with that of DNA strands, the hydrodynamic diameter of the DNA becomes smaller, which is attributed to the size confinement effects. The duration time for the linear DNA translocation events increases monotonically with the nanopore length. By comparing the spatial configurations of DNA strands through nanopores with different diameters, it is found that the nanopore with large diameter has enough space to allow the DNA strand to translocate through with complex conformation. With the decrease of the nanopore diameter, the folded part of the DNA is prone to be straightened by the nanopore, which leads to the increase in the occurrence frequency of the linear DNA translocation events. Reducing the diameter of the nanopore to 2.5 nm allows the detection and discrimination of three nucleotide "G" and three nucleotide "T" homopolymer DNA strands based on differences in their physical dimensions.

  19. Drawing a fine line on endogenous retroelement activity

    PubMed Central

    Castro-Diaz, Nathaly; Friedli, Marc; Trono, Didier

    2015-01-01

    Endogenous retroelements (EREs) are essential motors of evolution yet require careful control to prevent genomic catastrophes, notably during the vulnerable phases of epigenetic reprogramming that occur immediately after fertilization and in germ cells. Accordingly, a variety of mechanisms restrict these mobile genetic units. Previous studies have revealed the importance of KRAB-containing zinc finger proteins (KRAB-ZFPs) and their cofactor, KAP1, in the early embryonic silencing of endogenous retroviruses and so-called SVAs, but the implication of this transcriptional repression system in the control of LINE-1, the only known active autonomous retrotransposon in the human genome, was thought to be marginal. Two recent studies straighten the record by revealing that the KRAB/KAP system is key to the control of L1 in embryonic stem (ES) cells, and go further in demonstrating that DNA methylation and KRAB/KAP1-induced repression contribute to this process in an evolutionally dynamic fashion. These results shed light on the delicate equilibrium between higher vertebrates and endogenous retroelements, which are not just genetic invaders calling for strict control but rather a constantly renewed and nicely exploitable source of evolutionary potential. PMID:26442176

  20. Monitoring oxidative stress biomarkers in the lipidome: is there a roadmap for "human inspection"?

    PubMed

    Jungnickel, H; Tentschert, J; Luch, A

    2012-07-01

    Oxidative stress is more and more recognized as the underlying motif for a broad variety of diseases including cancer. Medicine faces the paramount task to develop better diagnostic tools and drug treatment prediction models in the future to significantly enhance the quality of life. Special interest will focus on earlystage disease biomarkers and biomarkers that could predict healing success at the earliest time point after the treatment started. The accelerated formation of so-called reactive oxygen species (ROS) is becoming widely regarded as the underlying process associated with many diseases like myocardial infarction, Alzheimer's, Parkinson's and kidney disease, etc. Once generated within cells and tissues, ROS can react with a variety of cellular metabolites like fatty acids, proteins or DNA. This review investigates the possibilities for various oxidized metabolites as well as proteomics, genomics and bioimaging biomarkers to serve as early-stage disease biomarkers or biomarkers for drug treatment success. We also assess the value of a step-by-step or cascade biomarker approach as a new paradigm in medical diagnostics. Examples are given for possible analytical methodology and tools as well as statistical methods that could be applied. Such an approach may straighten the road toward new medical diagnostics and treatment regimes, which ultimately could lead to a significantly enhanced medical service for patients suffering from chronic and debilitating or deadly diseases including cancer. Examples from recent research are given to show the progress and possibilities for the proposed model. PMID:22292439

  1. The Effects of Urbanization and Flood Control on Sediment Discharge of a Southern California River, Evidence of a Dilution Effect

    NASA Astrophysics Data System (ADS)

    Warrick, J. A.; Orzech, K. M.; Rubin, D. M.

    2004-12-01

    The southern California landscape has undergone dramatic urbanization and population growth during the past 60 years and currently supports almost 20 million inhabitants. During this time, rivers of the region have been altered with damming, channel straightening and hardening, and water transfer engineering. These changes have drastically altered water and sediment discharge from most of the region's drainage basins. Here we focus on changes in sediment discharge from the largest watershed of southern California, the Santa Ana River. Order-of-magnitude drops in the suspended sediment rating curves (the relationship between suspended sediment concentration and instantaneous river discharge) are observed between 1967 and 2001, long after the construction of a major flood control dam in 1941. These sediment concentration decreases do not, however, represent alteration of the total sediment flux from the basin (a common interpretation of sediment rating curves), but rather a dilution of suspended sediment by increases (approx. 4x) in stormwater discharge associated with urbanization. Increases in peak and total stormwater discharge are consistent with runoff patterns from urbanizing landscapes, supporting our hypothesis that the diluting water originated from stormwater runoff generated in urban areas both up- and downstream of dams. Our dilution hypothesis is further supported with water and sediment budgets, dilution calculations, and suspended and bed grain size information.

  2. Use of autologous grafts in the treatment of acquired penile curvature: An experience of 33 cases

    PubMed Central

    Khawaja, Abdul Rouf; Dar, Tanveer Iqbal; Zahur, Suhael; Tariq, Sheikh; Hamid, Arf; Wani, M. S.; Wazir, B. S.; Iqbal, Arsheed

    2016-01-01

    Aim: The objective was to compare the use of autologous dermal and temporalis fascia grafts in the treatment of acquired penile curvatures. Materials and Methods: It was a prospective observational study of 33 cases, conducted in Sher-i-Kashmir Institute of Medical Sciences, Srinagar from March 2007 to September 2013. All the patients had stable Peyronies disease (PD). Dorsal, dorsolateral and vental curvatures with good preoperative erections were included. PD index with visual analog scales for curvature was used preoperatively. An informed written consent was taken from all the patients with main emphasis on erectile dysfunction. Results: After an average follow up of 2 years, complete straightening of penis was observed in all patients with satisfactory sexual intercourse in 30 patients (90%). Three patients (10%) required frequent use of type 5 phosphodiesterase inhibitors for adequate erections. Overall 91% of patients and partners were satisfied with the procedure and cosmetically donor site was better in temporalis fascia graft site. No rejection of any graft was noted and glans hypoesthesia was noticed in 4 patients (12%). None of the patients required penile prosthesis. Total operative time for harvesting and application of the graft was more in dermal grafts (>3 hrs) than for temporalis fascia graft (2 hrs). Conclusion: Tunical lengthening procedures by autologous free grafts represents a safe and reproducible technique. A good preoperative erectile function is required for tunical lengthening procedure. Temporalis fascia graft is thin, tough membrane and effective graft for PD with good cosmetic and functional results. PMID:27141196

  3. Ultra-stretchable conductors based on buckled super-aligned carbon nanotube films.

    PubMed

    Yu, Yang; Luo, Shu; Sun, Li; Wu, Yang; Jiang, Kaili; Li, Qunqing; Wang, Jiaping; Fan, Shoushan

    2015-06-14

    Ultra-stretchable conductors are fabricated by coating super-aligned carbon nanotube (SACNT) films on pre-strained polydimethylsiloxane (PDMS) substrates and forming buckled SACNT structures on PDMS after release of the pre-strain. The parallel SACNT/PDMS conductors demonstrate excellent stability with normalized resistance changes of only 4.1% under an applied strain as high as 200%. The SACNT/PDMS conductors prepared with cross-stacked SACNT films show even lower resistance variation. The parallel SACNT/PDMS conductors exhibit high durability with a resistance increase of less than 5% after 10,000 cycles at 150% strain. In situ microscopic observations demonstrate that the buckled SACNT structures are straightened during the stretching process with reversible morphology evolution and thus the continuous SACNT conductive network can be protected from fracture. Due to the excellent electrical and mechanical properties of SACNT films and the formation of the buckled structure, SACNT/PDMS films exhibit high stretchability and durability, possessing great potential for use as ultra-stretchable conductors for wearable electronics, sensors, and energy storage devices. PMID:25985762

  4. Cell Autonomous Shape Changes in Germband Retraction

    NASA Astrophysics Data System (ADS)

    Lynch, Holley; Kim, Elliott; Gish, Robert; Hutson, M. Shane

    2012-02-01

    Germband retraction involves the cohesive movement and regulated cellular mechanics of two tissues on the surface of fruit fly embryos, the germband and the amnioserosa. The germband initially forms a `U' shape, curling from the ventral surface, around the posterior of the embryo, and onto the dorsal surface; the amnioserosa lies between the arms of this `U'. Retraction straightens the germband and leaves it only on the ventral side. During retraction, the germband becomes clearly segmented with deep furrows between segments, and its cells elongate towards the amnioserosa, along what becomes the dorsal-ventral axis. To determine the importance of these changes for the overall movement of the tissues, we observed embryos that did not complete germband retraction due to targeted laser ablation of half the amnioserosa. Without the chemical and mechanical influence of the amnioserosa, germband furrows still formed and germband cells still elongated; however, this elongation was misaligned compared to unablated embryos. Thus, furrow formation and cell elongation in the germband are autonomous, but insufficient to drive proper tissue motion. These results suggest that part of the necessary role of the amnioserosa is proper orientation of germband cell elongation.

  5. Asymmetric distribution of the pulmonary blood flow between the right and left lungs in d-transposition of the great arteries.

    PubMed

    Muster, A J; Paul, M H; Van Grondelle, A; Conway, J J

    1976-09-01

    Pulmonary angiograms, radionuclide lung images and chest roentgenograms were evaluated regarding the incidence, magnitude and natural evolution of maldistribution of the pulmonary blood flow between the lungs in 63 patients with dextrotransposition of the great arteries. Approximately half of these patients had some degree of greater perfusion of the right relative to the left lung. A significant correlation was demonstrated between the incidence of this maldistribution of blood flow and the angulation between the main and the right pulmonary arteries. For any given angulation between these vessels, additional pulmonary stenosis increased the incidence of disparity in perfusion. Our observations suggest the following developmental mechanisms: The maldistribution in flow results from the abnormal rightward inclination of the main pulmonary artery in the transposition malformation which straightens the flow axis from the main to the right pulmonary artery. Under these circumstances the momentum of the blood in the main pulmonary artery carries the blood preferentially into the right pulmonary artery. This momentum is increased when there is stenosis of the left ventricular outflow tract. Consequent differences in the mechanical properties of the two pulmonary vascular beds can increase this maldistribution. The disparity in perfusion between the lungs is not present in newborns with d-transposition, appears to be progressive in severity and in time may result in almost complete cessation of effective perfusion of the left lung. The effect of the Mustard operation on this abnormality of flow is discussed. PMID:961610

  6. Designing a bio-inspired self-propelling hydrogel micro-swimmer

    NASA Astrophysics Data System (ADS)

    Nikolov, Svetoslav; Yeh, Peter; Alexeev, Alexander

    2014-11-01

    Artificial micro-swimmers have found numerous applications in microfluidics, drug delivery systems, and nanotechnology. In our current research we use dissipative particle dynamics to design and optimize a self-propelling hydrogel micro-swimmer with an X-shaped flat geometry and bi-layered hydrogel structure. The two polymeric layers that bind to each other have identical material properties but distinctive chemical responses to external stimuli. In the presence of outside stimuli one of the layers swells where the other remains passive resulting in hydrogel bending. Our simulations demonstrate that under periodic applications of an external stimulus this actuation routine is capable of creating time-irreversible motion in a low Reynolds number environment. Initially, when the external stimulus is introduced a forward stroke is initiated, as the swimmer first expands and then bends. When the outside stimulus is removed the forward stroke is terminated and a backward stroke begins, as the swimmer contracts and then straightens. Propulsion results due to the difference in momentum exchange between the forward and backward strokes. We use our simulations to probe how alterations in the material properties of the bi-layered hydrogel can affect swimming performance. Support from NSF CAREER Award (DMR-1255288) is gratefully acknowledged.

  7. Fuel Damage Reduction by Installation of Particle Traps in the Feedwater Lines

    SciTech Connect

    Henriksson, Mats; Westin, Johan; Lindqvist, Hans; Lundstrom, Anders; Alavyoon, Farid; Kaipainen, Tapio

    2006-07-01

    Fuel damages are commonly caused by grinding of the cladding due to debris entering the reactor pressure vessel. In order to reduce the probability for fuel damages so-called particle traps have been developed and are currently in operation in two Swedish nuclear power plants. The particle traps are of type axial centrifugal separators, and are characterized by a robust design, high separation rate and low pressure drop (typically less than 1 bar). Special care has been taken in the design of the flow straightener, which efficiently eliminates the swirl in the flow. The model tests show that the Swirl number downstream of the particle trap is typically the same order of magnitude or less than that downstream of a pipe bend. The particles are separated from the main flow and collected in a separate chamber, which is emptied only during the outages. Traps have been developed for both upward or downward flow direction, with feedwater flows from 300 to 900 kg/s. The present paper describes the development work, which is primarily based on full-scale model tests supported by CFD-calculations. Some operating experiences from plants in which particle traps currently are in use are also reported. (authors)

  8. Calibration of the NASA Glenn 8- by 6-Foot Supersonic Wind Tunnel (1996 and 1997 Tests)

    NASA Technical Reports Server (NTRS)

    Arrington, E. Allen

    2012-01-01

    There were several physical and operational changes made to the NASA Glenn Research Center 8- by 6-Foot Supersonic Wind Tunnel during the period of 1992 through 1996. Following each of these changes, a facility calibration was conducted to provide the required information to support the research test programs. Due to several factors (facility research test schedule, facility downtime and continued facility upgrades), a full test section calibration was not conducted until 1996. This calibration test incorporated all test section configurations and covered the existing operating range of the facility. However, near the end of that test entry, two of the vortex generators mounted on the compressor exit tailcone failed causing minor damage to the honeycomb flow straightener. The vortex generators were removed from the facility and calibration testing was terminated. A follow-up test entry was conducted in 1997 in order to fully calibrate the facility without the effects of the vortex generators and to provide a complete calibration of the newly expanded low speed operating range. During the 1997 tunnel entry, all planned test points required for a complete test section calibration were obtained. This data set included detailed in-plane and axial flow field distributions for use in quantifying the test section flow quality.

  9. Diagnostic and therapeutic applications of water-immersion colonoscopy

    PubMed Central

    Sugimoto, Shinya; Mizukami, Takeshi

    2015-01-01

    Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications. PMID:26074684

  10. Atmospheric pressure flow reactor: Gas phase chemical kinetics under tropospheric conditions without wall effects

    NASA Technical Reports Server (NTRS)

    Koontz, Steven L. (Inventor); Davis, Dennis D. (Inventor)

    1991-01-01

    A flow reactor for simulating the interaction in the troposphere is set forth. A first reactant mixed with a carrier gas is delivered from a pump and flows through a duct having louvers therein. The louvers straighten out the flow, reduce turbulence and provide laminar flow discharge from the duct. A second reactant delivered from a source through a pump is input into the flowing stream, the second reactant being diffused through a plurality of small diffusion tubes to avoid disturbing the laminar flow. The commingled first and second reactants in the carrier gas are then directed along an elongated duct where the walls are spaced away from the flow of reactants to avoid wall interference, disturbance or turbulence arising from the walls. A probe connected with a measuring device can be inserted through various sampling ports in the second duct to complete measurements of the first and second reactants and the product of their reaction at selected XYZ locations relative to the flowing system.

  11. Symptoms of discoid lateral menisci

    PubMed Central

    Mutlu, Serhat; Mutlu, Harun; Mutlu, Burcu; Guler, Olcay; Duymus, Tahir Mutlu

    2014-01-01

    Purpose This study aims to determine the symptoms of the patients with discoid lateral meniscus. Methods We prospectively collected cases of the knees with discoid lateral meniscus. Twenty patients (7 female, 13 male) admitted between January 2012 and February 2014 were enrolled in this study. The mean age of the patients was 34 years (range 28–40). Results The identified symptoms of a discoid lateral meniscus were “pain, stiffness, popping of the knee, feeling that the knee is “giving way”, inability to fully extend (straighten) the knee”. Thirteen patients (65%) had pain, 11 (55%) had popping of the knee, 4 (20%) had stiffness, 2 (10%) had “giving way” feeling, and 1 (5%) had inability to fully extend the knee. These symptoms did not prevent any patient's daily activities. No patients required surgical treatment. Conclusions Pain and popping of the knee were the most common symptoms in patients with a discoid lateral meniscus. The other symptoms were stiffness, feeling that the knee is “giving way”, and inability to fully extend the knee, respectively. No symptoms had been required surgical treatment. PMID:25561753

  12. Borrelia burgdorferi tissue morphologies and imaging methodologies.

    PubMed

    MacDonald, A B

    2013-08-01

    This manuscript offers an image presentation of diverse forms of Borrelia burgdorferi spirochetes which are not spiral or corkscrew shaped. Explanations are offered to justify the legitimacy of tissue forms of Borrelia which may confuse the inexperienced microscopic examiner and which may lead to the misdiagnosis of non-spiral forms as artifacts. Images from the author's personal collection of Borrelia burgdorferi images and a few select images of Borrelia burgdorferi from the peer-reviewed published literature are presented. A commentary justifying each of the image profiles and a survey of the imaging modalities utilized provides the reader with a frame of reference. Regularly spiraled Borrelia are rarely seen in solid tissues. A variety of straightened, undulating, and clipped-off profiles are demonstrated, and the structural basis for each image is explained. Tissue examination is a diagnostic tool and a quality control for judging the eradication or the persistence of borreliosis following attempts to eradicate the infection with antibiotic therapy. The presence or absence of chronic Lyme borreliosis may be objectively adjudicated by tissue examinations which demonstrate or which fail to show pathogenic microbes in patients who have received a full course of antibiotics. PMID:23479042

  13. New insights in understanding plasma-catalysis reaction pathways: study of the catalytic ozonation of an acetaldehyde saturated Ag/TiO2/SiO2 catalyst

    NASA Astrophysics Data System (ADS)

    Sauce, Sonia; Vega-González, Arlette; Jia, Zixian; Touchard, Sylvain; Hassouni, Khaled; Kanaev, Andrei; Duten, Xavier

    2015-07-01

    This paper is a preliminary study intended to straighten out the role of reactive oxygen species in the activation mechanisms occurring in a plasma driven catalysis process for acetaldehyde decomposition. For this purpose, the interaction between the surface, the pollutant and one of the main oxidative species generated by non-thermal plasma, namely ozone, was studied. Acetaldehyde catalytic ozonation over a nanostructured Ag/TiO2/SiO2 catalyst is carried out at room temperature and atmospheric pressure, and followed by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). For this, the catalyst is firstly saturated with acetaldehyde. At the end of the saturation, acetaldehyde and crotonaldehyde, its condensation product, are identified as the major adsorbed species. In a second step, the surface ozonation is carried out and three additional intermediates are identified, namely, acetone, formic acid and acetic acid. Gaseous CO, CO2, methyl formate and methyl acetate are detected at the DRIFTS outlet, evidencing the partial mineralization of the adsorbed species. A global reaction scheme is proposed for explaining the formation of those adsorbed intermediates and gaseous products. This proposed heterogeneous ozone induced chemistry has to be taken into account when associating non-thermal plasma in air to a catalyst. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  14. The molecular kink paradigm for rubber elasticity: Numerical simulations of explicit polyisoprene networks at low to moderate tensile strains

    NASA Astrophysics Data System (ADS)

    Hanson, David E.

    2011-08-01

    Based on recent molecular dynamics and ab initio simulations of small isoprene molecules, we propose a new ansatz for rubber elasticity. We envision a network chain as a series of independent molecular kinks, each comprised of a small number of backbone units, and the strain as being imposed along the contour of the chain. We treat chain extension in three distinct force regimes: (Ia) near zero strain, where we assume that the chain is extended within a well defined tube, with all of the kinks participating simultaneously as entropic elastic springs, (II) when the chain becomes sensibly straight, giving rise to a purely enthalpic stretching force (until bond rupture occurs) and, (Ib) a linear entropic regime, between regimes Ia and II, in which a force limit is imposed by tube deformation. In this intermediate regime, the molecular kinks are assumed to be gradually straightened until the chain becomes a series of straight segments between entanglements. We assume that there exists a tube deformation tension limit that is inversely proportional to the chain path tortuosity. Here we report the results of numerical simulations of explicit three-dimensional, periodic, polyisoprene networks, using these extension-only force models. At low strain, crosslink nodes are moved affinely, up to an arbitrary node force limit. Above this limit, non-affine motion of the nodes is allowed to relax unbalanced chain forces. Our simulation results are in good agreement with tensile stress vs. strain experiments.

  15. The effect of a flexed elbow on bowling speed in cricket.

    PubMed

    Marshall, Robert; Ferdinands, René

    2003-01-01

    The laws of bowling in cricket state 'a ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand'. Recently two prominent bowlers, under suspicion for transgressing this law, suggested that they are not 'throwing' but due to an elbow deformity are forced to bowl with a bent bowling arm. This study examined whether such bowlers can produce an additional contribution to wrist/ball release speed by internal rotation of the upper arm. The kinematics of a bowling arm were calculated using a simple two-link model (upper arm and forearm). Using reported internal rotation speeds of the upper arm from baseball and waterpolo, and bowling arm kinematics from cricket, the change in wrist speed was calculated as a function of effective arm length, and wrist distance from the internal rotation axis. A significant increase in wrist speed was noted. This suggests that bowlers who can maintain a fixed elbow flexion during delivery can produce distinctly greater wrist/ball speeds by using upper arm internal rotation. PMID:14658246

  16. Temperature-Dependent Phase Behaviors in Cylinder-Forming Block Copolymers

    PubMed Central

    Ahn, Dae Up; Sancaktar, Erol

    2009-01-01

    We demonstrate that the temperature-dependent phase behaviors of parallel and perpendicular cylinder-forming block copolymers are governed by domain-domain segregation forces inherently present in block copolymer material itself. With increasing temperature, a parallel cylinder-forming block copolymer experienced a parallel cylinder straightening process before the order-disorder transition (ODT) and did not show long-range composition fluctuations near the ODT temperature due to the weak segregation forces between the block domains. A perpendicular cylinder-forming block copolymer with a strong segregation force between the block domains displayed cylinder orientation transition from perpendicular to parallel below the ODT temperature. On the other hand, a perpendicular cylinder-forming block copolymer material with an exceptionally strong segregation force between the block domains maintained its initial perpendicular cylinder orientation up to near the ODT temperature. In both cases of perpendicular cylinder-forming block copolymers, submicrometer-scale long-range composition fluctuations were observed well above the ODT temperature due to their intrinsically strong segregation forces between the block domains. PMID:19564947

  17. Controlling hollow relativistic electron beam orbits with an inductive current divider

    SciTech Connect

    Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.; Cooperstein, G.; Hinshelwood, D. D.; Ottinger, P. F.; Rittersdorf, I. M.; Schumer, J. W.; Weber, B. V.; Zier, J. C.

    2015-02-06

    A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I1), while the outer conductor carries the remainder (I2). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I2-I1), while the average force on the envelope (the beam width) is proportional to the beam current Ib = (I2 + I1). The values of I1 and I2 depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. As a result, solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.

  18. Controlling hollow relativistic electron beam orbits with an inductive current divider

    DOE PAGESBeta

    Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.; Cooperstein, G.; Hinshelwood, D. D.; Ottinger, P. F.; Rittersdorf, I. M.; Schumer, J. W.; Weber, B. V.; Zier, J. C.

    2015-02-06

    A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I1), while the outer conductor carries the remainder (I2). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I2-I1), while the average force on the envelope (the beam width) is proportional to the beam current Ib = (I2 + I1). The values of I1more » and I2 depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. As a result, solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.« less

  19. Controlling hollow relativistic electron beam orbits with an inductive current divider

    SciTech Connect

    Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.; Cooperstein, G.; Hinshelwood, D. D.; Ottinger, P. F.; Rittersdorf, I. M.; Schumer, J. W.; Weber, B. V.; Zier, J. C.

    2015-02-15

    A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I{sub 1}), while the outer conductor carries the remainder (I{sub 2}). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I{sub 2}-I{sub 1}), while the average force on the envelope (the beam width) is proportional to the beam current I{sub b} = (I{sub 2} + I{sub 1}). The values of I{sub 1} and I{sub 2} depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. Solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.

  20. Major cranial changes during Triceratops ontogeny.

    PubMed

    Horner, John R; Goodwin, Mark B

    2006-11-01

    This is the first cranial ontogenetic assessment of Triceratops, the well-known Late Cretaceous dinosaur distinguished by three horns and a massive parietal-squamosal frill. Our analysis is based on a growth series of 10 skulls, ranging from a 38 cm long baby skull to about 2 m long adult skulls. Four growth stages correspond to a suite of ontogenetic characters expressed in the postorbital horns, frill, nasal, epinasal horn and epoccipitals. Postorbital horns are straight stubs in early ontogeny, curve posteriorly in juveniles, straighten in subadults and recurve anteriorly in adults. The posterior margin of the baby frill is deeply scalloped. In early juveniles, the frill margin becomes ornamented by 17-19 delta-shaped epoccipitals. Epoccipitals are dorsoventrally compressed in subadults, strongly compressed and elongated in adults and ultimately merge onto the posterior frill margin in older adults. Ontogenetic trends within and between growth stages include: posterior frill margin transitions from scalloped to wavy and smooth; progressive exclusion of the supraoccipital from the foramen magnum; internal hollowing at the base of the postorbital horns; closure of the midline nasal suture; fusion of the epinasal onto the nasals; and epinasal expansion into a morphologically variable nasal horn. We hypothesize that the changes in horn orientation and epoccipital shape function to allow visual identity of juveniles, and signal their attainment of sexual maturity. PMID:17015322

  1. Major cranial changes during Triceratops ontogeny

    PubMed Central

    Horner, John R; Goodwin, Mark B

    2006-01-01

    This is the first cranial ontogenetic assessment of Triceratops, the well-known Late Cretaceous dinosaur distinguished by three horns and a massive parietal–squamosal frill. Our analysis is based on a growth series of 10 skulls, ranging from a 38 cm long baby skull to about 2 m long adult skulls. Four growth stages correspond to a suite of ontogenetic characters expressed in the postorbital horns, frill, nasal, epinasal horn and epoccipitals. Postorbital horns are straight stubs in early ontogeny, curve posteriorly in juveniles, straighten in subadults and recurve anteriorly in adults. The posterior margin of the baby frill is deeply scalloped. In early juveniles, the frill margin becomes ornamented by 17–19 delta-shaped epoccipitals. Epoccipitals are dorsoventrally compressed in subadults, strongly compressed and elongated in adults and ultimately merge onto the posterior frill margin in older adults. Ontogenetic trends within and between growth stages include: posterior frill margin transitions from scalloped to wavy and smooth; progressive exclusion of the supraoccipital from the foramen magnum; internal hollowing at the base of the postorbital horns; closure of the midline nasal suture; fusion of the epinasal onto the nasals; and epinasal expansion into a morphologically variable nasal horn. We hypothesize that the changes in horn orientation and epoccipital shape function to allow visual identity of juveniles, and signal their attainment of sexual maturity. PMID:17015322

  2. Tricho-Dento-Osseous Syndrome: Diagnosis and Dental Management

    PubMed Central

    Al-Batayneh, Ola B.

    2012-01-01

    Tricho-dento-osseous (TDO) syndrome is a rare, autosomal dominant disorder principally characterised by curly hair at infancy, severe enamel hypomineralization and hypoplasia and taurodontism of teeth, sclerotic bone, and other defects. Diagnostic criteria are based on the generalized enamel defects, severe taurodontism especially of the mandibular first permanent molars, an autosomal dominant mode of inheritance, and at least one of the other features (i.e., nail defects, bone sclerosis, and curly, kinky or wavy hair present at a young age that may straighten out later). Confusion with amelogenesis imperfecta is common; however, taurodontism is not a constant feature of any of the types of amelogenesis imperfecta. Management of TDO requires a team approach, proper documentation, and a long-term treatment and follow-up plan. The aim of treatment is to prevent problems such as sensitivity, caries, dental abscesses, and loss of occlusal vertical dimension through attrition of hypoplastic tooth structure. Another aim is to restore function of the dentition and enhance the esthetics and self-esteem of the patient. This paper proposes treatment approaches that include preventive, restorative, endodontic, prosthetic, and surgical options to management. In addition, it sheds light on the difficulties faced during dental treatment of such cases. PMID:22969805

  3. Cable load sensing device

    DOEpatents

    Beus, Michael J.; McCoy, William G.

    1998-01-01

    Apparatus for sensing the magnitude of a load on a cable as the cable is employed to support the load includes a beam structure clamped to the cable so that a length of the cable lies along the beam structure. A spacer associated with the beam structure forces a slight curvature in a portion of the length of cable under a cable "no-load" condition so that the portion of the length of cable is spaced from the beam structure to define a cable curved portion. A strain gauge circuit including strain gauges is secured to the beam structure by welding. As the cable is employed to support a load the load causes the cable curved portion to exert a force normal to the cable through the spacer and on the beam structure to deform the beam structure as the cable curved portion attempts to straighten under the load. As this deformation takes place, the resistance of the strain gauges is set to a value proportional to the magnitude of the normal strain on the beam structure during such deformation. The magnitude of the normal strain is manipulated in a control device to generate a value equal to the magnitude or weight of the load supported by the cable.

  4. Sensitive Detection of Phosphorus Deficiency in Plants Using Chlorophyll a Fluorescence.

    PubMed

    Frydenvang, Jens; van Maarschalkerweerd, Marie; Carstensen, Andreas; Mundus, Simon; Schmidt, Sidsel Birkelund; Pedas, Pai Rosager; Laursen, Kristian Holst; Schjoerring, Jan K; Husted, Søren

    2015-09-01

    Phosphorus (P) is a finite natural resource and an essential plant macronutrient with major impact on crop productivity and global food security. Here, we demonstrate that time-resolved chlorophyll a fluorescence is a unique tool to monitor bioactive P in plants and can be used to detect latent P deficiency. When plants suffer from P deficiency, the shape of the time-dependent fluorescence transients is altered distinctively, as the so-called I step gradually straightens and eventually disappears. This effect is shown to be fully reversible, as P resupply leads to a rapid restoration of the I step. The fading I step suggests that the electron transport at photosystem I (PSI) is affected in P-deficient plants. This is corroborated by the observation that differences at the I step in chlorophyll a fluorescence transients from healthy and P-deficient plants can be completely eliminated through prior reduction of PSI by far-red illumination. Moreover, it is observed that the barley (Hordeum vulgare) mutant Viridis-zb(63), which is devoid of PSI activity, similarly does not display the I step. Among the essential plant nutrients, the effect of P deficiency is shown to be specific and sufficiently sensitive to enable rapid in situ determination of latent P deficiency across different plant species, thereby providing a unique tool for timely remediation of P deficiency in agriculture. PMID:26162430

  5. Improved pulmonary nodule classification utilizing lung parenchyma texture features

    NASA Astrophysics Data System (ADS)

    Dilger, S. K.; Judisch, A.; Uthoff, J.; Hammond, E.; Newell, J. D.; Sieren, J. C.

    2015-03-01

    Current computer-aided diagnosis (CAD) models, developed to determine the malignancy of pulmonary nodules, characterize the nodule's shape, density, and border. Analyzing the lung parenchyma surrounding the nodule is an area that has been minimally explored. We hypothesize that improved classification of nodules can be achieved through the inclusion of features quantified from the surrounding lung tissue. From computed tomography (CT) data, feature extraction techniques were developed to quantify the parenchymal and nodule textures, including a three-dimensional application of Laws' Texture Energy Measures. Border irregularity was investigated using ray-casting and rubber-band straightening techniques, while histogram features characterized the densities of the nodule and parenchyma. The feature set was reduced by stepwise feature selection to a few independent features that best summarized the dataset. Using leave-one-out cross-validation, a neural network was used for classification. The CAD tool was applied to 50 nodules (22 malignant, 28 benign) from high-resolution CT scans. 47 features, including 39 parenchymal features, were statistically significant, with both nodule and parenchyma features selected for classification, yielding an area under the ROC curve (AUC) of 0.935. This was compared to classification solely based on the nodule yielding an AUC of 0.917. These preliminary results show an increase in performance when the surrounding parenchyma is included in analysis. While modest, the improvement and large number of significant parenchyma features supports our hypothesis that the parenchyma contains meaningful data that can assist in CAD development.

  6. Channel degradation in southeastern Nebraska Rivers

    USGS Publications Warehouse

    Wahl, Kenneth L.; Weiss, Linda S.

    1995-01-01

    Many stream channels in southeastern Nebraska were dredged and straightened during 1904-15. The resulting channels were both shorter and steeper than the original channels. Tests for time trends were conducted using the nonparametric Kendall tau test to see if the channels have responded to these changes. Tests were conducted on the stages associated with specific discharges and on measurement characteristics at gaging stations. Tests also were conducted on hydrologic forcing variables (annual mean precipitation, annual peak discharges, annual mean discharge, and annual mean base flows). The null hypothesis (that the data were free from trend) was rejected for stages associated with the mean of the annual discharges for 6 of 7 gaging stations in the study area, but was accepted for all 3 gages on the main stem of the Missouri River. The trends at the 6 streamflow gaging stations were for decreasing stages (degrading channels) for specific discharges. The rates of change ranged from about 0.2 to 0.5 m per decade. Mean stream bed elevations computed for individual discharge measurements at these streamflow gaging stations confirmed that the channels are degrading. However, neither the precipitation nor flow variables show evidence of trends. The tendency for the channels to degrade thus cannot be attributed to changes in runoff characteristics and are assumed to be a response to the channel modifications in the early 1900's. Indications are that the channels presently are continuing to degrade.

  7. Strain hardening during mechanical twining and dislocation channeling in irradiated 316 stainless steels

    SciTech Connect

    Byun, Thak Sang; Hashimoto, Naoyuki

    2007-01-01

    Localized deformation mechanisms and strain-hardening behaviors in irradiated 316 and 316LN stainless steels were investigated, and a theoretical model was proposed to explain the linear strain-hardening behavior during the localized deformation. After low temperature irradiation to significant doses the deformation microstructure changed from dislocation tangles to channels or to mechanical twins. It was also observed that irradiation hardening straightened gliding dislocations and increased the tendency for forming pileups. Regardless of these microstructural changes, the strain-hardening behavior was relatively insensitive to the irradiation. This dose-independent strain-hardening rate resulted in dose independence of the true stress parameters such as the plastic instability stress and true fracture stress. In the proposed model, the long-range back stress was formulated as a function of the number of pileup dislocations per slip band and the number of slip bands in a grain. The calculation results confirmed the experimental observation that strain-hardening rate was insensitive to the change in deformation mechanism because the long-range back stress hardening became as high as the hardening by tangled dislocations.

  8. A CFD study of steady flow of a Newtonian and non-Newtonian fluid through a mildly curved tube with stent-like wall protrusions patterns

    NASA Astrophysics Data System (ADS)

    Prince, Chekema; Peterson, Sean D.

    2012-11-01

    Early stent designs caused vessel straightening post-implantation and motivated the exploration of flow in the stent vicinity using straight pipe models with stent-like protrusion patterns. Recent advancements in stent design allow the device to better conform to the native vessel curvature. The present study focuses on the investigation of steady flow through mildly curved pipes with protrusion patterns that emulate current stent designs using computational fluid dynamics (CFD). The modeled geometries include various protrusion frequencies, heights, and widths with flow behavior within the range of physiologically relevant Dean numbers. The results are compared to smooth wall curved pipe models as well as straight pipe protrusion studies. Differences in flow behavior pre/post stent implantation will be discussed. Particular attention will be paid to flow characteristics, such as wall shear stress (WSS) magnitude and WSS gradients, indicative of potential stent failure. Newtonian and non-Newtonian fluid models will be utilized to discuss their impact on flow patterns. The study findings can be used to optimize stent design to mitigate flow conditions associated with stent failure.

  9. Myosin molecule packing within the vertebrate skeletal muscle thick filaments. A complete bipolar model.

    PubMed

    Skubiszak, Ludmila; Kowalczyk, Leszek

    2002-01-01

    Computer modelling related to the real dimensions of both the whole filament and the myosin molecule subfragments has revealed two alternative modes for myosin molecule packing which lead to the head disposition similar to that observed by EM on the surface of the cross-bridge zone of the relaxed vertebrate skeletal muscle thick filaments. One of the modes has been known for three decades and is usually incorporated into the so-called three-stranded model. The new mode differs from the former one in two aspects: (1) myosin heads are grouped into asymmetrical cross-bridge crowns instead of symmetrical ones; (2) not the whole myosin tail, but only a 43-nm C-terminus of each of them is straightened and near-parallel to the filament axis, the rest of the tail is twisted. Concurrent exploration of these alternative modes has revealed their influence on the filament features. The parameter values for the filament models as well as for the building units depicting the myosin molecule subfragments are verified by experimental data found in the literature. On the basis of the new mode for myosin molecule packing a complete bipolar structure of the thick filament is created. PMID:12545190

  10. Mathematical formulation of biomechanical parameters used in orthodontic treatment

    NASA Astrophysics Data System (ADS)

    Balakrishna, A.; Vamsi, Ch. Raghu; Rao, V. D. Prasad; Swamy, Ch. Kishore; Kuladeep, B.

    2015-05-01

    Orthodontic Treatment is being widely practiced around the world for teeth straightening and extraction to improve alignment of remaining teeth. Here, forces are applied to correct the position of teeth. The force applied on the teeth isn't calibrated and applied arbitrarily based on the recommendations from scientific research and experience of the orthodontist. The number of settings and the total time required for the completion of treatment also remains arbitrary. So, there is a need for determining the force which is actually acting on the teeth and determining the optimal force required for the treatment of each and every individual case. In this paper a mathematical relation is derived between the force applied on the tooth and tooth displacement by considering a 2nd order non-homogeneous linear differential equation. As the tooth displacement is not a direct function of force applied, Biomechanical parameters like mass of tooth, stiffness and damping coefficient of periodontal ligament & alveolar bone are involved in the differential equation. By solving the equation, tooth displacement thereby, tooth velocity can be obtained for a particular force. On the other hand, based on the dimensions of the model, orthodontist could determine the total tooth displacement required for each setting of the treatment, so that, the total displacement is covered. The orthodontist uses the data and applies the required force on to the teeth, based on which the orthodontist can plan his treatment procedure and reduce the number of settings, total treatment time and also increases the success rate of the treatment.

  11. Control of Transverse Corner Cracks on Low-Carbon Steel Slabs

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Yang, Xiaogang; Li, Shusen; Li, Ming; Ma, Wei

    2014-09-01

    In this article, the formation mechanism of transverse corner cracks on a low-carbon steel continuous-casting slab was investigated. The factors influencing the transverse corner cracks were discussed. The hot ductility of the low-carbon steel within 600°C and 1250°C was detected using a thermal simulator Gleeble 1500 (Dynamic Systems, Inc., Poestenkill, NY) to determine the embrittling temperature range of the steel. The temperature of the slab varied with time, especially at the slab corner, and it was calculated and discussed. It was found that transverse corner cracks were generated on the ferrite films along grain boundaries, and there was little decarburization layer near the cracks. According to the calculated temperature at slab corner, the cooling water flow rate and cooling strategy were optimized by adjusting the cooling water flow rate at each spray cooling zone to avoid the embrittling temperature range at the bending and straightening segments of the caster. As a result, the transverse corner cracks were successfully weakened.

  12. Semi-automated nanoprecipitation-system--an option for operator independent, scalable and size adjustable nanoparticle synthesis.

    PubMed

    Rietscher, René; Thum, Carolin; Lehr, Claus-Michael; Schneider, Marc

    2015-06-01

    The preparation of nano-sized carrier systems increasingly moved into focus of pharmaceutical research and industry in the past decades. Besides the drug load and properties of the selected polymer/lipid, the size of such particles is one of the most important parameters regarding their use as efficient drug delivery systems. However, the preparation of nanoparticles with different sizes in a controlled manner is challenging, especially in terms of reproducibility and scale-up possibility. To overcome these hurdles we developed a system relying on nanoprecipitation, which meets all these requirements of an operator independent, scalable and size-adjustable nanoparticle synthesis-the Semi-Automated Nanoprecipitation-System. This system enables the adaption of the particle size to specific needs based on the process parameters-injection rate, flow rate and polymer concentration-identified within this study. The basic set-up is composed of a syringe pump and a gear pump for a precise control of the flow and injection speed of the system. Furthermore, a home-made tube-straightener guarantees a curvature-free injection point. Thus it could be shown that the production of poly(lactide-co-glycolide) nanoparticles from 150 to 600 nm with a narrow size distribution in a controlled semi-automatic manner is possible. PMID:25547536

  13. Patterned fiber composites: Process, characterization, and damping performance

    NASA Astrophysics Data System (ADS)

    Pratt, William F.

    1999-11-01

    This dissertation reports the invention, characterization, and performance of a new fiber-reinforced material system termed "Patterned Fiber Composites". The invention of a process and a machine concept that is capable of producing resin pre-impregnated composite materials (pre-preg) with a controlled pattern in the lay of the reinforcing fiber is reported. Two laminates with opposing wavy fiber patterns are combined with a viscoelastic layer in a sandwiched construction. When this combination is placed under load the fibers tend to straighten and cause differential shearing in the sandwiched viscoelastic layer. This shearing action causes stretching of the long chain polymers in the viscoelastic which in turn generates heat, dissipates energy, and causes damping in the structure. Carbon fiber based material has been produced with the process, characterized, and used in tubular structures to demonstrate the capabilities of this new material system. Changes to the rule-of-mixtures have been proposed which will account for the unique properties of wavy patterned fiber composites while retaining their applicability in the more general sense to analyze conventional composites. An investigation into the capabilities of existing finite element analysis programs has shown areas where changes are required to fix deficiencies in the programs. Methodologies are proposed that should allow more efficient solution methods. A practical boring bar has been designed and built with this new material that exhibited damping improvements of 1200% over conventional steel carbide bars while retaining high stiffness.

  14. A 3d particle simulation code for heavy ion fusion accelerator studies

    SciTech Connect

    Friedman, A.; Bangerter, R.O.; Callahan, D.A.; Grote, D.P.; Langdon, A.B. ); Haber, I. )

    1990-06-08

    We describe WARP, a new particle-in-cell code being developed and optimized for ion beam studies in true geometry. We seek to model transport around bends, axial compression with strong focusing, multiple beamlet interaction, and other inherently 3d processes that affect emittance growth. Constraints imposed by memory and running time are severe. Thus, we employ only two 3d field arrays ({rho} and {phi}), and difference {phi} directly on each particle to get E, rather than interpolating E from three meshes; use of a single 3d array is feasible. A new method for PIC simulation of bent beams follows the beam particles in a family of rotated laboratory frames, thus straightening'' the bends. We are also incorporating an envelope calculation, an (r, z) model, and 1d (axial) model within WARP. The BASIS development and run-time system is used, providing a powerful interactive environment in which the user has access to all variables in the code database. 10 refs., 3 figs.

  15. A Micromechanics Finite-Strain Constitutive Model of Fibrous Tissue

    PubMed Central

    Chen, Huan; Liu, Yi; Zhao, Xuefeng; Lanir, Yoram; Kassab, Ghassan S.

    2011-01-01

    Biological tissues have unique mechanical properties due to the wavy fibrous collagen and elastin microstructure. In inflation, a vessel easily distends under low pressure but becomes stiffer when the fibers are straightened to take up the load. The current microstructural models of blood vessels assume affine deformation; i.e., the deformation of each fiber is assumed to be identical to the macroscopic deformation of the tissue. This uniform-field (UF) assumption leads to the macroscopic (or effective) strain energy of the tissue that is the volumetric sum of the contributions of the tissue components. Here, a micromechanics-based constitutive model of fibrous tissue is developed to remove the affine assumption and to take into consideration the heterogeneous interactions between the fibers and the ground substance. The development is based on the framework of a recently developed second-order homogenization theory, and takes into account the waviness, orientations, and spatial distribution of the fibers, as well as the material nonlinearity at finite-strain deformation. In an illustrative simulation, the predictions of the macroscopic stress-strain relation, and the statistical deformation of the fibers are compared to the UF model, as well as finite-element (FE) simulation. Our predictions agree well with the FE results, while the UF predictions significantly overestimate. The effects of fiber distribution and waviness on the macroscopic stress-strain relation are also investigated. The present mathematical model may serves as a foundation for native as well as for engineered tissues and biomaterials. PMID:21927506

  16. Phosphorylation of Ser283 enhances the stiffness of the tropomyosin head-to-tail overlap domain.

    PubMed

    Lehman, William; Medlock, Greg; Li, Xiaochuan Edward; Suphamungmee, Worawit; Tu, An-Yue; Schmidtmann, Anja; Ujfalusi, Zoltán; Fischer, Stefan; Moore, Jeffrey R; Geeves, Michael A; Regnier, Michael

    2015-04-01

    The ends of coiled-coil tropomyosin molecules are joined together by nine to ten residue-long head-to-tail "overlapping domains". These short four-chained interconnections ensure formation of continuous tropomyosin cables that wrap around actin filaments. Molecular Dynamics simulations indicate that the curvature and bending flexibility at the overlap is 10-20% greater than over the rest of the molecule, which might affect head-to-tail filament assembly on F-actin. Since the penultimate residue of striated muscle tropomyosin, Ser283, is a natural target of phosphorylating enzymes, we have assessed here if phosphorylation adjusts the mechanical properties of the tropomyosin overlap domain. MD simulations show that phosphorylation straightens the overlap to match the curvature of the remainder of tropomyosin while stiffening it to equal or exceed the rigidity of canonical coiled-coil regions. Corresponding EM data on phosphomimetic tropomyosin S283D corroborate these findings. The phosphorylation-induced change in mechanical properties of tropomyosin likely results from electrostatic interactions between C-terminal phosphoSer283 and N-terminal Lys12 in the four-chain overlap bundle, while promoting stronger interactions among surrounding residues and thus facilitating tropomyosin cable assembly. The stiffening effect of D283-tropomyosin noted correlates with previously observed enhanced actin-tropomyosin activation of myosin S1-ATPase, suggesting a role for the tropomyosin phosphorylation in potentiating muscle contraction. PMID:25726728

  17. Dense-body aggregates as plastic structures supporting tension in smooth muscle cells.

    PubMed

    Zhang, Jie; Herrera, Ana M; Paré, Peter D; Seow, Chun Y

    2010-11-01

    The wall of hollow organs of vertebrates is a unique structure able to generate active tension and maintain a nearly constant passive stiffness over a large volume range. These properties are predominantly attributable to the smooth muscle cells that line the organ wall. Although smooth muscle is known to possess plasticity (i.e., the ability to adapt to large changes in cell length through structural remodeling of contractile apparatus and cytoskeleton), the detailed structural basis for the plasticity is largely unknown. Dense bodies, one of the most prominent structures in smooth muscle cells, have been regarded as the anchoring sites for actin filaments, similar to the Z-disks in striated muscle. Here, we show that the dense bodies and intermediate filaments formed cable-like structures inside airway smooth muscle cells and were able to adjust the cable length according to cell length and tension. Stretching the muscle cell bundle in the relaxed state caused the cables to straighten, indicating that these intracellular structures were connected to the extracellular matrix and could support passive tension. These plastic structures may be responsible for the ability of smooth muscle to maintain a nearly constant tensile stiffness over a large length range. The finding suggests that the structural plasticity of hollow organs may originate from the dense-body cables within the smooth muscle cells. PMID:20709732

  18. Medical and surgical therapies for alopecias in black women.

    PubMed

    Callender, Valerie D; McMichael, Amy J; Cohen, George F

    2004-01-01

    Hair loss is a common problem that challenges the patient and clinician with a host of cosmetic, psychological and medical issues. Alopecia occurs in both men and women, and in all racial and ethnic populations, but the etiology varies considerably from group to group. In black women, many forms of alopecia are associated with hair-care practices (e.g., traction alopecia, trichorrhexis nodosa, and central centrifugal cicatricial alopecia). The use of thermal or chemical hair straightening, and hair braiding or weaving are examples of styling techniques that place African American women at high risk for various "traumatic" alopecias. Although the exact cause of these alopecias is unknown, a multifactorial etiology including both genetic and environmental factors is suspected. A careful history and physical examination, together with an acute sensitivity to the patient's perceptions (e.g., self-esteem and social problems), are critical in determining the best therapy course. Therapeutic options for these patients range from alteration of current hair grooming practices or products, to use of specific medical treatments, to hair replacement surgery. Since early intervention is often a key to preventing irreversible alopecia, the purpose of the present article is to educate the dermatologist on all aspects of therapy for hair loss in black women--including not only a discussion of the main medical and surgical therapies but also an overview of ethnic hair cosmetics, specific suggestions for alterations of hair-care practices, and recommendations for patient education and compliance. PMID:15113284

  19. Non-invasive MRI Assessments of Tissue Microstructures and Macromolecules in the Eye upon Biomechanical or Biochemical Modulation

    PubMed Central

    Ho, Leon C.; Sigal, Ian A.; Jan, Ning-Jiun; Yang, Xiaoling; van der Merwe, Yolandi; Yu, Yu; Chau, Ying; Leung, Christopher K.; Conner, Ian P.; Jin, Tao; Wu, Ed X.; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S.; Chan, Kevin C.

    2016-01-01

    The microstructural organization and composition of the corneoscleral shell (CSS) determine the biomechanical behavior of the eye, and are important in diseases such as glaucoma and myopia. However, limited techniques can assess these properties globally, non-invasively and quantitatively. In this study, we hypothesized that multi-modal magnetic resonance imaging (MRI) can reveal the effects of biomechanical or biochemical modulation on CSS. Upon intraocular pressure (IOP) elevation, CSS appeared hyperintense in both freshly prepared ovine eyes and living rat eyes using T2-weighted MRI. Quantitatively, transverse relaxation time (T2) of CSS increased non-linearly with IOP at 0–40 mmHg and remained longer than unloaded tissues after being unpressurized. IOP loading also increased fractional anisotropy of CSS in diffusion tensor MRI without apparent change in magnetization transfer MRI, suggestive of straightening of microstructural fibers without modification of macromolecular contents. Lastly, treatments with increasing glyceraldehyde (mimicking crosslinking conditions) and chondroitinase-ABC concentrations (mimicking glycosaminoglycan depletion) decreased diffusivities and increased magnetization transfer in cornea, whereas glyceraldehyde also increased magnetization transfer in sclera. In summary, we demonstrated the changing profiles of MRI contrast mechanisms resulting from biomechanical or biochemical modulation of the eye non-invasively. Multi-modal MRI may help evaluate the pathophysiological mechanisms in CSS and the efficacy of corneoscleral treatments. PMID:27561353

  20. Hysteresis of soft joints embedded with fluid-filled microchannels

    PubMed Central

    Ghatak, Animangsu; Majumder, Abhijit; Kumar, Rajendra

    2008-01-01

    Many arthropods are known to achieve dynamic stability during rapid locomotion on rough terrains despite the absence of an elaborate nervous system. While muscle viscoelasticity and its inherent friction have been thought to cause this passive absorption of energy, the role of embedded microstructures in muscles and muscle joints has not yet been investigated. Inspired by the soft and flexible hinge joints present in many of these animals, we have carried out displacement-controlled bending of thin elastic slabs embedded with fluid-filled microchannels. During loading, the slab bends uniformly to a critical curvature, beyond which the skin covering the channel buckles with a catastrophic decrease in load. In the reverse cycle, the buckled skin straightens out but at a significantly lower load. In such a loading–unloading cycle, this localized buckling phenomenon results in a dynamic change in the geometry of the joint, which leads to a significant hysteresis in elastic energy. The hysteresis varies nonlinearly with channel diameters and thicknesses of the slab, which is captured by a simple scaling analysis of the phenomenon. PMID:18611846

  1. Comparative biodiversity along a gradient of agricultural landscapes

    NASA Astrophysics Data System (ADS)

    Burel, Françoise; Baudry, Jacques; Butet, Alain; Clergeau, Philippe; Delettre, Yannick; Le Coeur, Didier; Dubs, Florence; Morvan, Nathalie; Paillat, Gilles; Petit, Sandrine; Thenail, Claudine; Brunel, Etienne; Lefeuvre, Jean-Claude

    1998-02-01

    The aim of this study is to compare biodiversity in contrasted landscape units within a small region. In western France agricultural intensification leads to changes in landscape structure: permanent grasslands are ploughed, fields enlarged and surrounding hedgerows removed or deteriorated, brooks are straightened and cleaned. South of Mont Saint Michel Bay, four landscape units have been identified along an intensification gradient. Several taxonomic groups (small mammals, birds, insects and plants) have been used to evaluate the characteristics of biodiversity along this gradient. The hypothesis that intensification of agricultural practices lead to changes in biodiversity has been tested. Biodiversity is measured by the species richness, Shannon's diversity index, equitability and similarity indexes. Our results show that intensification of agriculture does not always lead to a decrease in species richness, but to several functional responses according to taxonomic groups, either no modification, or stability by replacement of species, or loss of species. For most of the studied taxonomic groups species richness does not vary greatly along the gradient. Depending on the landscape structure and farming systems this gradient is probably truncated and does not allow to show major changes in species richness. An alternative hypothesis is that used indexes are not sensitive enough to reveal changes in biodiversity. Nevertheless, similarity indexes reveal that sensitivity to changes varies, invertebrates being more likely to perceive the dynamics of the landscapes studied than vertebrates or plants. These points have to be taken into consideration when elaborating policies for sustainable agriculture or nature conservation.

  2. Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

    SciTech Connect

    Pollack, B.R.

    1996-05-01

    Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 {mu}m in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

  3. Why helicity injection causes coronal flux tubes to develop an axially invariant cross-section

    NASA Astrophysics Data System (ADS)

    Bellan, P. M.

    It is shown that electric current flowing along an axially non-uniform magnetic flux tube produces an associated non-linear, non-conservative axial MHD force which pumps plasma from regions where the flux tube diameter is small to regions where it is large. In particular, this force will ingest plasma into the ends of a fat, initially potential flux tube and then pump the ingested plasma towards the middle bulge, thereby causing mass accumulation at the bulge.The ingested plasma convects frozen-in toroidal magnetic flux which accumulates at the middle as well. Flux accumulation at the bulge has the remarkable consequence of causing the bulge to diminish so that the flux tube becomes axially uniform as observed in coronal loops. Stagnation of the convergent plasma flow at the middle heats the plasma. A small number of tail particles bouncing synchronously between approaching fluid elements can be Fermi-accelerated to very high energies. Since driving a current along a flux tube is tantamount to helicity injection into the flux tube, this mass ingestion, heating, and straightening should be ubiquitous to helicity injection processes.

  4. Remedies to the problem of child labor: the situation in the apparel industry.

    PubMed

    Mazur, J

    1993-09-01

    When you realize how long the problem of child labor has been around, anyone who ventures into the terrain of remedies obviously needs a long memory and not a little optimism. What have we tried? What has worked? And what has not worked? To answer these questions, we must first look at how we have diagnosed the problem. Some say that the return of child labor is due to the present recession. Hard-pressed businesses are looking for cheap and cheaper labor. Sweatshops proliferate. When the recession recedes, so will child labor. If it were that simple, we could all congratulate ourselves on having conducted this enlightened symposium and go home without worrying much more about the problem. The magic hand of the market, in due course, will straighten it all out. Let me tell you something about the apparel industry in New York where new laws and strict enforcement make the only difference. Over 80% of OSHA inspections were triggered by the state's Apparel Task Force. PMID:8238033

  5. Mathematical Modelling of Solidification in a Curved Strand During Continuous Casting of Steel

    NASA Astrophysics Data System (ADS)

    Maurya, Ambrish; Jha, Pradeep Kumar

    2016-06-01

    A two dimensional fluid flow, heat transfer and solidification model has been developed for a curved shape continuous steel slab caster. The strand has been divided in various sections depending upon cooling conditions in the mold and Secondary Cooling Zone (SCZ). The model was validated against the experimental results reported in the literature for solid shell thickness in the mold. CFD software ANSYS Fluent has been used for solving the differential equations of heat transfer and fluid flow. Surface temperature distribution has been predicted while; the thickness of solid shell formed in the mold and SCZ has been calculated by finding the liquid fraction of steel within the domain. Process parameters such as, casting speed and cooling rate has been varied to analyse their effects on metallurgical length and solid shell thickness at the mold exit. The analysis was based on keeping the shell thickness between 10 and 14 mm at mold exit and metallurgical length less than the cut-off length but having complete solidification after the straightening zone.

  6. The effect of post-annealing on the critical current recovery of bending-deformed (Bi,Pb)-2223/Ag tapes

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Xie, L.; Li, P.; Qu, T.-M.; Song, Y.; Wang, X.-C.; Han, Z.

    2007-10-01

    (Bi,Pb)-2223/Ag tape fabricated by PIT methods is a promising candidate for electrical power application. In these applications, the tape often undergoes a winding process, which leads to the degradation of the critical current. In this paper, we report the effect of post-annealing on the critical current (Ic) recovery of bent-deformed (Bi,Pb)-2223/Ag multi-filamentary tapes. The tapes were bent at room temperature with different curvatures, then straightened and post-annealed with different processing parameters, including post-annealing temperature, dwelling time and oxygen partial pressure. The experiment results show that rather high Ic value could be obtained by post-annealing even for the tapes whose bending strain was 0.8%. SEM observation shows that the decreasing in Ic value is caused by the formation and propagation of transverse micro-cracks in the (Bi,Pb)-2223 filaments and the effect of post-annealing could be related to the healing of micro-cracks caused by bending strain as well as the improving of grain connectivity.

  7. Ground reaction forces of Olympic and World Championship race walkers.

    PubMed

    Hanley, Brian; Bissas, Athanassios

    2016-01-01

    Race walking is an Olympic event where no visible loss of contact should occur and the knee must be straightened until midstance. The purpose of this study was to analyse ground reaction forces of world-class race walkers and associate them with key spatiotemporal variables. Nineteen athletes race walked along an indoor track and made contact with two force plates (1000 Hz) while being filmed using high-speed videography (100 Hz). Race walking speed was correlated with flight time (r = .46, p = .049) and flight distance (r = .69, p = .001). The knee's movement from hyperextension to flexion during late stance meant the vertical push-off force that followed midstance was smaller than the earlier loading peak (p < .001), resulting in a flattened profile. Athletes with narrower stride widths experienced reduced peak braking forces (r = .49, p = .046), peak propulsive forces (r = .54, p = .027), peak medial forces (r = .63, p = .007) and peak vertical push-off forces (r = .60, p = .011). Lower fluctuations in speed during stance were associated with higher stride frequencies (r = .69, p = .001), and highlighted the importance of avoiding too much braking in early stance. The flattened trajectory and consequential decrease in vertical propulsion might help the race walker avoid visible loss of contact (although non-visible flight times were useful in increasing stride length), while a narrow stride width was important in reducing peak forces in all three directions and could improve movement efficiency. PMID:25429613

  8. Utilization of urethral plate in hypospadias surgery

    PubMed Central

    Snodgrass, Warren T.

    2008-01-01

    Purpose Recognition the urethral plate comprises tissues that normally should have created the urethra was an important milestone in hypospadias surgery, giving rise to new operative repairs - most notably the tubularized incised plate technique. This article reviews the current state of the art for hypospadias repair using tubularized, incised plate (TIP). Materials and Methods Personal experience and literature reports were reviewed to summarize use of TIP urethroplasty for distal, proximal, and re-operative hypospadias repairs. Results The TIP can be used to correct all distal and most proximal hypospadias. The major contraindication is ventral curvature that leads to urethral plate transection for straightening, which is only necessary in some proximal cases. Reoperations can also be performed using TIP provided the urethral plate has been maintained and is not grossly scarred. Complication rates are comparable to previously used techniques, while cosmetic appearance after TIP is considered superior to other available procedures. Conclusions Recognition of the urethral plate and its incorporation into the neourethra has revolutionized hypospadias repair. The most commonly used operative procedure today is TIP. PMID:19468397

  9. Two-stage repair in hypospadias

    PubMed Central

    Haxhirexha, K. N.; Castagnetti, M.; Rigamonti, W.; Manzoni, G. A.

    2008-01-01

    We provide the reader with a nonsystematic review concerning the use of the two-stage approach in hypospadias repairs. A one-stage approach using the tubularized incised plate urethroplasty is a well-standardized approach for the most cases of hypospadias. Nevertheless, in some primary severe cases, in most hypospadias failures and in selected patients with balanitis xerotica obliterans a two-stage approach is preferable. During the first stage the penis is straightened, if necessary and the urethral plate is substituted with a graft of either genital (prepuce) or extragenital origin (oral mucosa or postauricular skin). During the second stage, performed around 6 months later, urethroplasty is accomplished by graft tubulization. Graft take is generally excellent, with only few cases requiring an additional inlay patch at second stage due to graft contracture. A staged approach allows for both excellent cosmetic results and a low morbidity including an overall 6% fistula rate and 2% stricture rate. Complications usually occur in the first year after the second stage and are higher in secondary repairs. Complications tend to decrease as experience increases and use of additional waterproofing layers contributes to reduce the fistula rate significantly. Long-term cosmetic results are excellent, but voiding and ejaculatory problems may occur in as much as 40% of cases if a long urethral tube is constructed. The procedure has a step learning curve but because of its technical simplicity does not require to be confined only to highly specialized centers. PMID:19468402

  10. Validation of an axial flow blood pump: computational fluid dynamics results using particle image velocimetry.

    PubMed

    Su, Boyang; Chua, Leok Poh; Wang, Xikun

    2012-04-01

    A magnetically suspended axial flow blood pump is studied experimentally in this article. The pump casing enclosed a three-blade straightener, a two-blade impeller shrouded by a permanent magnet-embedded cylinder, and a three-blade diffuser. The internal flow fields were simulated earlier using computational fluid dynamics (CFD), and the pump characteristic curves were determined. The simulation results showed that the internal flow field was basically streamlined, except the diffuser region. Particle image velocimetry (PIV) measurement of the 1:1 pump model was conducted to validate the CFD result. In order to ensure the optical access, an acrylic prototype was fabricated with the impeller driven by a servomotor instead, as the magnet is opaque. In addition to the transparent model, the blood analog fluid with the refractive index close to that of acrylic was used to avoid refraction. According to the CFD results, the axial flow blood pump could generate adequate pressure head at the rotating speed of 9500rpm and flow rate of 5L/min, and the same flow condition was applied during the PIV measurement. Through the comparisons, it was found that the experimental results were close to those obtained by CFD and had thus validated the CFD model, which could complement the limitation of the measurement in assessing the more detailed flow fields of the axial flow pump. PMID:22040356

  11. An Excel™-VBA programme for the analysis of current velocity profiles

    NASA Astrophysics Data System (ADS)

    Le Roux, J. P.; Brodalka, M.

    2004-10-01

    VPA is an Excel spreadsheet to facilitate the analysis of current velocity profiles and its application to sediment transport studies in steady, uniform, open-channel flows. The program requires input values such as the water temperature (from which the density and dynamic viscosity are calculated), the channel depth and slope, current velocities as measured at different heights above the bed, bedform length and height, as well as the sediment density and median size. The latter can be provided as sieve diameters, fall diameters or as phi values. The velocity profiles are plotted on two graphs, one being a traditional plot of velocity versus height or distance from the bed and the other comparing the observed profile with theoretical profiles for smooth, transitional and rough boundary conditions. VBA macros are provided to clear the spreadsheet before new profiles are analysed, update the formulas, straighten out the velocity profiles, calculate the shear velocity, and save the data on a separate sheet for further analysis. The programme is applied to a new and more accurate method to determine the shear velocity, which can be used to predict the bedload discharge over plane beds and is also incorporated into a dimensionally correct suspended load transport equation combining the parameters most important in sediment transport. A dimensionally correct bedload discharge equation based upon the mean excess flow velocity is also proposed for plane beds, ripples and dunes.

  12. A Gauss-Seidel Iteration Scheme for Reference-Free 3-D Histological Image Reconstruction

    PubMed Central

    Daum, Volker; Steidl, Stefan; Maier, Andreas; Köstler, Harald; Hornegger, Joachim

    2015-01-01

    Three-dimensional (3-D) reconstruction of histological slice sequences offers great benefits in the investigation of different morphologies. It features very high-resolution which is still unmatched by in-vivo 3-D imaging modalities, and tissue staining further enhances visibility and contrast. One important step during reconstruction is the reversal of slice deformations introduced during histological slice preparation, a process also called image unwarping. Most methods use an external reference, or rely on conservative stopping criteria during the unwarping optimization to prevent straightening of naturally curved morphology. Our approach shows that the problem of unwarping is based on the superposition of low-frequency anatomy and high-frequency errors. We present an iterative scheme that transfers the ideas of the Gauss-Seidel method to image stacks to separate the anatomy from the deformation. In particular, the scheme is universally applicable without restriction to a specific unwarping method, and uses no external reference. The deformation artifacts are effectively reduced in the resulting histology volumes, while the natural curvature of the anatomy is preserved. The validity of our method is shown on synthetic data, simulated histology data using a CT data set and real histology data. In the case of the simulated histology where the ground truth was known, the mean Target Registration Error (TRE) between the unwarped and original volume could be reduced to less than 1 pixel on average after 6 iterations of our proposed method. PMID:25312918

  13. Live minimal path for interactive segmentation of medical images

    NASA Astrophysics Data System (ADS)

    Chartrand, Gabriel; Tang, An; Chav, Ramnada; Cresson, Thierry; Chantrel, Steeve; De Guise, Jacques A.

    2015-03-01

    Medical image segmentation is nowadays required for medical device development and in a growing number of clinical and research applications. Since dedicated automatic segmentation methods are not always available, generic and efficient interactive tools can alleviate the burden of manual segmentation. In this paper we propose an interactive segmentation tool based on image warping and minimal path segmentation that is efficient for a wide variety of segmentation tasks. While the user roughly delineates the desired organs boundary, a narrow band along the cursors path is straightened, providing an ideal subspace for feature aligned filtering and minimal path algorithm. Once the segmentation is performed on the narrow band, the path is warped back onto the original image, precisely delineating the desired structure. This tool was found to have a highly intuitive dynamic behavior. It is especially efficient against misleading edges and required only coarse interaction from the user to achieve good precision. The proposed segmentation method was tested for 10 difficult liver segmentations on CT and MRI images, and the resulting 2D overlap Dice coefficient was 99% on average..

  14. Geophysical investigation of a sinkhole in the northern Harz foreland (North Germany)

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg; Romanov, Douchko

    2009-07-01

    The creek Jerstedter Bach is part of the Ringelheimer Mulde along the northern rim of the Harz Mountains in Northern Germany, a trough structure comprising steeply dipping limestones. The limestones are well karstified and drain parts of the region efficiently via sub-surface flow. As the entire region is intensively used by agriculture, contamination of the fast-flowing karst aquifer is a potential problem. During 2006, a small sinkhole (Windmühlenweg) developed alongside the Jerstedter Bach close to the city of Goslar. The sinkhole enlarged rapidly, with a small cave within the gravel cover diverting part of the creek to the subsurface karst catchment. Geophysical methods (gravimetry, geoelectrics) were used around the sinkhole to determine its extent and possible evolution. A negative Bouguer anomaly was found over the sinkhole, indicating more voids further downstream. The geoelectric survey helped to identify the old meandering course of the small river, which was straightened during the cultural land reform in the twentieth century.

  15. Finite Element Analysis of ECAP, TCAP, RUE and CGP Processes

    NASA Astrophysics Data System (ADS)

    Patil, Deepak C.; Kallannavar, Vinayak; Bhovi, Prabhakar M.; Kori, S. A.; Venkateswarlu, K.

    2016-02-01

    A finite element method was applied to study the various severe plastic deformation processes like, Equal Channel Angular Pressing (ECAP), Tubular Channel Angular Pressing (TCAP), Repetitive Upsetting and Extrusion (RUE) and Constrained Groove Pressing (CGP), considering aluminum AA-390 alloy as specimen material for all these processes. FEA simulation was carried out using AFDEX simulation tool. Effect of the various ECAP process parameters like, die corner angle, channel angle, and the coefficient of friction were analyzed. The die corner angles were divided into 2 equal parts for increasing the effectiveness of ECAP process, thereby increasing the channel number from 2 to 3 and further, their influence on ECAP process was investigated. A 3D simulation of TCAP was carried out for die shapes like triangular and trapezoidal, and variation of the generated stress and strain was plotted. In CGP, four cycle operation was carried out; wherein each cycle is composed of corrugating the specimen and subsequent straightening to original dimension. During RUE process, a maximum effective stress of 683.1 MPa was induced in the specimen after processing it for four complete cycles of RUE process; whereas the maximum strain induced during the same condition was 3.715.

  16. The stress corrosion resistance and the cryogenic temperature mechanical properties of annealed Nitronic 60 bar material

    NASA Technical Reports Server (NTRS)

    Montano, J. W. L.

    1977-01-01

    Ambient and cryogenic temperature mechanical properties and the ambient temperature stress corrosion properties of annealed, straightened, and centerless ground Nitronic 60 stainless steel alloy bar material are presented. The mechanical properties of longitudinal specimens were evaluated at test temperatures from ambient to liquid hydrogen. The tensile test data indicated increasing strength with decreasing temperature to -196 C. Below liquid nitrogen temperature the smooth tensile and notched tensile strengths decreased slightly while the elongation and reduction of area decreased drastically. The Charpy V-notched impact energy decreased steadily with decreasing test temperature. Stress corrosion tests were performed on longitudinal tensile specimens and transverse C-ring specimens exposed to: alternate immersion in a 3.5% NaCl bath; humidity cabinet; and a 5% salt spray atmosphere. The longitudinal tensile specimens experienced no corrosive attack. Approximately 3/4 of the transverse C-rings exposed to alternate immersion and to salt spray experienced a pitting attack on the top and bottom ends. Additional stress corrosion tests were performed on transverse tensile specimens. No failures occurred in the 90% stressed specimens exposed for 90 days in the alternate immersion and salt spray environments

  17. Therapeutic advances in the treatment of Peyronie's disease.

    PubMed

    Yafi, F A; Pinsky, M R; Sangkum, P; Hellstrom, W J G

    2015-07-01

    Peyronie's disease (PD) is an under-diagnosed condition with prevalence in the male population as high as 9%. It is a localized connective tissue disorder of the penis characterized by scarring of the tunica albuginea. Its pathophysiology, however, remains incompletely elucidated. For the management of the acute phase of PD, there are currently numerous available oral drugs, but the scientific evidence for their use is weak. In terms of intralesional injections, collagenase clostridium histolyticum is currently the only Food and Drug Administration-approved drug for the management of patients with PD and a palpable plaque with dorsal or dorsolateral curvature >30°. Other available intralesional injectable drugs include verapamil and interferon-alpha-2B, however, their use is considered off-label. Iontophoresis, shockwave therapy, and radiation therapy have also been described with unconvincing results, and as such, their use is currently not recommended. Traction therapy, as part of a multimodal approach, is an underused additional tool for the prevention of PD-associated loss of penile length, but its efficacy is dependent on patient compliance. Surgical therapy remains the gold standard for patients in the chronic phase of the disease. In patients with adequate erectile function, tunical plication and/or incision/partial excision and grafting can be offered, depending on degree of curvature and/or presence of destabilizing deformity. In patients with erectile dysfunction non-responsive to oral therapy, insertion of an inflatable penile prosthesis with or without straightening procedures should be offered. PMID:26097120

  18. The role of Nesbit's procedure in surgical reconstruction of penile deviation

    PubMed Central

    Martenstein, Christian; Peruth, Julia; Hamza, Amir

    2012-01-01

    Objective: We review our results after surgical reconstruction with the Nesbit’s procedure for congenital or acquired penile deviation. Patients and methods: Etiology of penile deviation, surgical outcome for straightening the penis, postoperative patient satisfaction and clinical findings were evaluated for 5 patients undergoing Nesbit’s procedure followed by a Medline review of contemporary literature regarding alternative surgical techniques. Follow-up included clinical examination, self-photography on erection and a standardized interview with erectile dysfunction assessment using IIEF-5 questionnaire. Results: Overall patient satisfaction was 100% in two patients, 2 patients were partly satisfied and 1 patient reported no satisfaction because of severe penile shortening with insufficiency for sexual intercourse postoperatively. Preoperative mean angulation of the penis was 42°. Four patients had Peyronie’s disease and 1 patient’s curvature resulted from an untreated penile fracture during sexual intercourse. Conclusion: The Nesbit technique can give satisfactory results for mild and moderate penile curvature. However, each technique for the reconstruction of penile deviation has its own advantages and disadvantages. Therefore proper patient selection has a major impact on further outcome. PMID:26504690

  19. Long-term results of the surgical treatment of Peyronie's disease with Egydio's technique: a European multicentre study

    PubMed Central

    Sansalone, Salvatore; Garaffa, Giulio; Djinovic, Rados; Pecoraro, Stefano; Silvani, Mauro; Barbagli, Guido; Zucchi, Alessandro; Vespasiani, Giuseppe; Loreto, Carla

    2011-01-01

    The long-term outcomes of 157 patients affected by Peyronie's disease (PD) who underwent penile straightening with Egydio's technique between January 2004 and December 2008 are reported. Only patients with PD who were stable for at least 6–12 months prior to surgery were enrolled in this study. Preoperative assessment included a dynamic echo colour Doppler ultrasound scan to evaluate the degree of penile deformity and the peak systolic velocity in the cavernosal arteries and an assessment of erectile function with the administration of the International Index of Erectile Function 5 (IIEF-5) questionnaire. Stretched penile length was recorded pre- and postoperatively. Surgical complications, cosmesis and sexual function, patient satisfaction and postoperative erectile function were assessed postoperatively at 3 months, 1 year and 2 years, respectively. After a median follow-up period of 20 months (range: 12–24 months), we found that mild residual curvature (12%) and glans hypoesthesia (3%) were the only causes of partial dissatisfaction. No rejection of the graft was observed. All patients recovered their ability to penetrate with no difficulty. In addition, an intraoperative average increase of 2.5 cm (range: 1.7–4.1 cm) in stretched penile length was recorded, with all patients engaging in penetrative sexual intercourse. In conclusion, this procedure represents a safe and reproducible technique for the correction of penile curvature resulting from PD and yields excellent cosmetic and functional results. PMID:21743482

  20. Two-stage repair in hypospadias.

    PubMed

    Haxhirexha, K N; Castagnetti, M; Rigamonti, W; Manzoni, G A

    2008-04-01

    We provide the reader with a nonsystematic review concerning the use of the two-stage approach in hypospadias repairs. A one-stage approach using the tubularized incised plate urethroplasty is a well-standardized approach for the most cases of hypospadias. Nevertheless, in some primary severe cases, in most hypospadias failures and in selected patients with balanitis xerotica obliterans a two-stage approach is preferable. During the first stage the penis is straightened, if necessary and the urethral plate is substituted with a graft of either genital (prepuce) or extragenital origin (oral mucosa or postauricular skin). During the second stage, performed around 6 months later, urethroplasty is accomplished by graft tubulization. Graft take is generally excellent, with only few cases requiring an additional inlay patch at second stage due to graft contracture. A staged approach allows for both excellent cosmetic results and a low morbidity including an overall 6% fistula rate and 2% stricture rate. Complications usually occur in the first year after the second stage and are higher in secondary repairs. Complications tend to decrease as experience increases and use of additional waterproofing layers contributes to reduce the fistula rate significantly. Long-term cosmetic results are excellent, but voiding and ejaculatory problems may occur in as much as 40% of cases if a long urethral tube is constructed. The procedure has a step learning curve but because of its technical simplicity does not require to be confined only to highly specialized centers. PMID:19468402

  1. In situ sensing of non-linear deformation and damage in epoxy particulate composites

    NASA Astrophysics Data System (ADS)

    Vadlamani, Venkat K.; Chalivendra, Vijaya; Shukla, Arun; Yang, Sze

    2012-07-01

    Damage sensing of epoxy particulate composites was investigated using multi-wall carbon nanotubes (MWCNTs) under quasi-static uniaxial tensile loading. Two types of particulates, namely (a) aluminum silicate hollow microspheres (cenospheres), and (b) liquid carboxyl-terminated butadiene acrylonitrile (CTBN) rubber were considered in this study. The influence of three different volume fractions of cenospheres (10%, 20% and 30%) and three different weight fractions of CTBN resin (10, 20 and 30 phr) on the electromechanical response was studied. A four-circumferential ring probe (FCRP) technique was employed to measure the electrical resistance of the test specimen as a function of the axial strain. The resistance-strain curve is compared with a simultaneously measured mechanical stress-strain curve. The electromechanical measurement show additional stages of material deformation not readily revealed from the mechanical stress-strain curve. The resistance change associated with the unfolding of entangled polymer chains and further straightening of the polymer chains decreased the distance between CNTs, causing improved electron hopping in all composites except 30% cenospheres composite. The U-shaped electrical response demonstrated by both 20 and 30 phr rubber composites exploited the CNT sensory network successfully by providing early warning of composite failure due to micro-crack propagation which resulted in breaking of the CNT network.

  2. Flow-induced crystallinity in polyethylene as probed by time-resolved Raman spectroscopy and optical microscopy

    NASA Astrophysics Data System (ADS)

    Kotula, Anthony; Hight Walker, Angela; Migler, Kalman

    2015-03-01

    The crystallization of polymer melts under flow is critically relevant to the polymer processing industry. Optical, thermal, and mechanical properties of semi-crystalline polymer products depend on the final crystallinity of the material, which depends on the structure and orientation of the initial molecular-scale crystal nuclei formed in flow. Here, we present a combination of optical microscopy and Raman scattering techniques to analyze structure formation in high density polyethylene during steady shear at low degrees of undercooling. When low shear rates (~ 1 s-1) are imposed after a temperature quench to less than 10 °C undercooling, fibrous structures aligned parallel to the flow direction appear over a period of minutes. Raman spectra indicate that chain straightening (consecutive trans chain conformation) precedes the growth of the crystalline phase, and increased shear increases the rate of growth of the consecutive trans and crystalline fractions. Complimentary Raman scattering experiments are performed on n-alkanes to compare conformational similarities in the molecular structure during the crystallization process.

  3. An Overview of Groundwater Governance and Management in China

    NASA Astrophysics Data System (ADS)

    Liu, J.; Qi, Y.; Zheng, C.

    2011-12-01

    Understanding the legislative and administrative water management systems is essential to translate hydrological expertise into real actions. This study provides an overview of groundwater governance and management in China, including the existing laws, regulations, institutional arrangements and governing practices. Respectable progress has been made in a relatively short period of time in the legislation of China's groundwater governance. However, the implementation of the laws and regulations has not been as successful as their formulation process. Groundwater overdraft and quality deterioration has not been fundamentally brought under control. Institutional deficiencies, statutory deficiencies, enforcement deficiencies, insufficient public participation and information disclosure are some of the major reasons for poor groundwater management in China. To better address the problems in contemporary groundwater management, the legislation system should firstly be improved. Secondly, institutional reforms are needed to straighten out several critical relationships, including the relationship between the national and local governments, the relationship among different ministries with water-related jurisdiction, and the relationship between river basin based and administrative division based management approaches. Thirdly, a national water-monitoring network should be constructed with improved metering techniques. Data publishing and information sharing should also be promoted.

  4. Optical and Calorimetric Studies of Cholesterol-Rich Filamentous, Helical Ribbon and Crystal Microstructures

    SciTech Connect

    Miroshnikova, Y. A.; Elsenbeck, M.; Zastavker, Y. V.; Kashuri, K; Iannacchione, G. S.

    2009-04-19

    Formation of biological self-assemblies at all scales is a focus of studies in fields ranging from biology to physics to biomimetics. Understanding the physico-chemical properties of these self-assemblies may lead to the design of bio-inspired structures and technological applications. Here we examine self-assembled filamentous, helical ribbon, and crystal microstructures formed in chemically defined lipid concentrate (CDLC), a model system for cholesterol crystallization in gallbladder bile. CDLC consists of cholesterol, bilayer-forming amphiphiles, micelle-forming amphiphiles, and water. Phase contrast and differential interference contrast (DIC) microscopy indicate the presence of three microstructure types in all samples studied, and allow for an investigation of the structures' unique geometries. Additionally, confocal microscopy is used for qualitative assessment of surface and internal composition. To complement optical observations, calorimetric (differential-scanning and modulation) experiments, provide the basis for an in-depth understanding of collective and individual thermal behavior. Observed ''transition'' features indicate clustering and ''straightening'' of helical ribbons into short, increasingly thickening, filaments that dissolve with increasing temperature. These results suggest that all microstructures formed in CDLC may coexist in a metastable chemical equilibrium. Further investigation of the CDLC thermal profile should uncover the process of cholesterol crystallization as well as the unique design and function of microstructures formed in this system.

  5. Mechanism of phospho-ubiquitin-induced PARKIN activation.

    PubMed

    Wauer, Tobias; Simicek, Michal; Schubert, Alexander; Komander, David

    2015-08-20

    The E3 ubiquitin ligase PARKIN (encoded by PARK2) and the protein kinase PINK1 (encoded by PARK6) are mutated in autosomal-recessive juvenile Parkinsonism (AR-JP) and work together in the disposal of damaged mitochondria by mitophagy. PINK1 is stabilized on the outside of depolarized mitochondria and phosphorylates polyubiquitin as well as the PARKIN ubiquitin-like (Ubl) domain. These phosphorylation events lead to PARKIN recruitment to mitochondria, and activation by an unknown allosteric mechanism. Here we present the crystal structure of Pediculus humanus PARKIN in complex with Ser65-phosphorylated ubiquitin (phosphoUb), revealing the molecular basis for PARKIN recruitment and activation. The phosphoUb binding site on PARKIN comprises a conserved phosphate pocket and harbours residues mutated in patients with AR-JP. PhosphoUb binding leads to straightening of a helix in the RING1 domain, and the resulting conformational changes release the Ubl domain from the PARKIN core; this activates PARKIN. Moreover, phosphoUb-mediated Ubl release enhances Ubl phosphorylation by PINK1, leading to conformational changes within the Ubl domain and stabilization of an open, active conformation of PARKIN. We redefine the role of the Ubl domain not only as an inhibitory but also as an activating element that is restrained in inactive PARKIN and released by phosphoUb. Our work opens up new avenues to identify small-molecule PARKIN activators. PMID:26161729

  6. Influences of high-flow events on a stream channel altered by construction of a highway bridge: a case study

    USGS Publications Warehouse

    Hedrick, Lara B.; Welsh, Stuart A.; Anderson, James T.

    2009-01-01

    Impacts of highway construction on streams in the central Appalachians are a growing concern as new roads are created to promote tourism and economic development in the area. Alterations to the streambed of a first-order stream, Sauerkraut Run, Hardy County, WV, during construction of a highway overpass included placement and removal of a temporary culvert, straightening and regrading of a section of stream channel, and armourment of a bank with a reinforced gravel berm. We surveyed longitudinal profiles and cross sections in a reference reach and the altered reach of Sauerkraut Run from 2003 through 2007 to measure physical changes in the streambed. During the four-year period, three high-flow events changed the streambed downstream of construction including channel widening and aggradation and then degradation of the streambed. Upstream of construction, at a reinforced gravel berm, bank erosion was documented. The reference section remained relatively unchanged. Knowledge gained by documenting channel changes in response to natural and anthropogenic variables can be useful for managers and engineers involved in highway construction projects.

  7. Unsteady Phenomena During Operation of the SSME Fuel Flowmeter

    NASA Astrophysics Data System (ADS)

    Marcu, Bogdan

    2002-07-01

    This report describes a part of the analysis carried in support of the SSME Fuel Flowmeter redesign, addressing a particular phenomenon known as "shifting" of the flowmeter constant value. It consists of a sudden change in the flowmeter indication, which occurs simultaneously with the onset of an oscillatory variation of the rotor speed. The change in the flowmeter indications does not correspond to a real change in the volumetric flow through the device. Several causes have been investigated in detail, in the past, without conclusive evidence towards a cause of this phenomenon. The present analysis addresses the flow physics through the flowmeter by assembling results from 3-D CFD calculations, airfoil CD/CL performance curves and mass moment of inertia characteristics of the rotor into a synergistic calculation which simulates the unsteady regime of the flowmeter operation. The results show that the 4-bladed rotor interacts with the periodic flow pattern created behind the flow straightener upstream in a manner that generates a steady, periodic fluctuation in the rotor's speed. The amplitude of this fluctuation is significantly smaller than the 0.5% of mean speed threshold which constitutes a flight operational limit. When manufacturing variations occur, however, the fluctuations are amplified and can generate a significant apparent change in the flowmeter indication. Two types of possible fabrication variations.which can occur even for parts fabricated within the accepted tolerances for the blade airfoil.are presented, together with their effect on the flowmeter operation.

  8. Development of a vascular prosthesis for a growing child. A graft expandable in vivo.

    PubMed

    Satoh, S; Niu, S; Kanda, K; Hirai, J; Doi, K; Oka, T

    1994-01-01

    Specially designed vascular prostheses that can be dilated after implantation using a percutaneous transluminal angioplasty (PTA) balloon catheter have been developed. The grafts are made of woven polyester fiber fabrics, the circumferential yarns of which consist of two different types of polyester fiber bundles: One is a straight weak bundle, the other is a strong bundle wound around the former. The graft with an initial diameter of 6 mm could be dilated to 9 mm by luminal inflation of the balloon four to five times at 10 atmospheres (atm) in vitro. After disrupting the weak bundle by the dilatation procedure, the strong bundles were straightened, which maintained the enlarged diameter of the new caliber. Grafts of 6 mm in initial diameter implanted into the thoracic aortas of mongrel dogs for 3 months also could be dilated in vivo by inflating the PTA four to five times at 15 atm, as found in the vitro study. Macroscopic observation revealed that, around the dilated grafts, only a tiny hematoma was formed and nominal subsequent bleeding was observed, which indicated that the dilatation procedure was performed safely. The graft, which enables adaptation of the hydrodynamic property of the graft to the increased blood flow by PTA after implantation, is applicable in a growing child. PMID:8555526

  9. Spatial instability of the rift in the St. Paul multifault transform fracture system, Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Sokolov, S. Yu.; Zaraiskaya, Yu. A.; Mazarovich, A. O.; Efimov, V. N.; Sokolov, N. S.

    2016-05-01

    The structure of the acoustic basement of the eastern part of the St. Paul multifault transform fracture system hosts rift paleovalleys and a paleonodal depression that mismatch the position of the currently active zones. This displacement zone, which is composed of five fault troughs, is unstable in terms of the position of the rift segments, which jumped according to redistribution of stresses. The St. Paul system is characterized by straightening of the transform transition between two remote segments of the Mid-Atlantic Ridge (MAR). The eastern part of the system contains anomalous bright-spot-like reflectors on the flattened basement, which is a result of atypical magmatism, that forms the standard ridge relief of the acoustic basement. Deformations of the acoustic basement have a presedimentation character. The present-day deformations with lower amplitude in comparison to the basement are accompanied by acoustic brightening of the sedimentary sequence. The axial Bouguer anomalies in the east of the system continue to the north for 120 km from the active segments of the St. Paul system. Currently seismically active segments of the spreading system are characterized by increasing amplitudes of the E-W displacement along the fault troughs. Cross-correlation of the lengths of the active structural elements of the MAR zone (segments of the ridge and transform fracture zones of displacement) indicates that, statistically, the multifault transform fracture system is a specific type of oceanic strike-slip faults.

  10. Temporal Evolution of Solar Energetic Particle Spectra

    NASA Astrophysics Data System (ADS)

    Doran, Donald J.; Dalla, Silvia

    2016-08-01

    During solar flares and coronal mass ejections, Solar Energetic Particles (SEPs) may be released into the interplanetary medium and near-Earth locations. The energy spectra of SEP events at 1 AU are typically averaged over the entire event or studied in a few snapshots. In this article we analyze the time evolution of the energy spectra of four large selected SEP events using a large number of snapshots. We use a multi-spacecraft and multi-instrument approach for the observations, obtained over a wide SEP energy range. We find large differences in the spectra at the beginning of the events as measured by different instruments. We show that over time, a wave-like structure is observed traveling through the spectra from the highest energies to the lowest energies, creating an "arch" shape that then straightens into a power law later in the event, after times on the order of 10 hours. We discuss the processes that determine SEP intensities and their role in shaping the spectral time evolution.

  11. Chiropractic management of a 30-year-old patient with Parsonage-Turner syndrome

    PubMed Central

    Charles, Eugene

    2011-01-01

    Objectives The purpose of this case report is to describe the chiropractic management of a patient presenting with right arm paralysis and a diagnosis of Parsonage-Turner syndrome. Clinical Features After receiving nerve entrapment release surgery, a 30-year-old man presented with a right arm contracture, atrophy, and weakness with general paralysis of the forearm and index finger of 6 weeks' duration. Intervention and Outcome The patient was provided chiropractic care that included high-velocity/low-amplitude spinal manipulation based upon applied kinesiology manual muscle testing, soft tissue trigger point therapy, exercises, and stretches. The patient demonstrated improvement in range of motion after the first treatment session. By the eighth treatment, he was able to fully straighten his arm. Three years later, the patient reported that he was able to do mountain climbing and that his arm was fully functional and pain-free. Conclusion For this patient, chiropractic care seemed to be successful in relieving his right arm paralysis and restoring normal arm movement. PMID:22654689

  12. Block model of western US kinematics from inversion of geodetic, fault slip, and earthquake data

    NASA Astrophysics Data System (ADS)

    McCaffrey, R.

    2003-12-01

    The active deformation of the southwestern US (30° to 41° N) is represented by a finite number of rotating, elastic spherical caps. Horizontal GPS velocities (1583), fault slip rates (94), and earthquake slip vectors (116) are inverted for block angular velocities, locking on block-bounding faults, and the rotation of individual GPS velocity fields relative to North America. GPS velocities are modeled as a combination of rigid block rotations and elastic strain rates resulting from interactions of adjacent blocks across bounding faults. The resulting Pacific - North America pole is indistinguishable from that of Beavan et al. (2001) and satisfies spreading in the Gulf of California and earthquake slip vectors in addition to GPS. The largest blocks, the Sierra Nevada - Great Valley and the eastern Basin and Range, show internal strain rates, after removing the elastic component, of only a few nanostrain/a, demonstrating long term approximately rigid behavior. Most fault slip data are satisfied except that the San Jacinto fault appears to be significantly faster than inferred from geology while the Coachella and San Bernardino segments of the San Andreas fault are slower, suggesting the San Andreas system is straightening out in Southern California. Vertical axis rotation rates for most blocks are clockwise and in magnitude more like the Pacific than North America. One exception is the eastern Basin and Range (242° E to 248° E) which rotates slowly anticlockwise about a pole offshore Baja.

  13. Man-induced gradient adjustment of the South Fork Forked Deer River, west Tennessee

    USGS Publications Warehouse

    Simon, A.; Robbins, C.H.

    1987-01-01

    Channel modifications from 1968 to 1969 on the South Fork Forked Deer River in western Tennessee have caused upstream degradation, downstream aggradation, and bank failures along the altered channels, adjacent reaches, and tributaries. The result of these adjustments is a general decrease in gradient as the channel attempts to absorb the imposed increase in energy conditions created by channelization. Headward degradation at a rate of approximately 2.57 km/yr on the South Fork Forked Deer River caused from 1.52 m to about 3.14 m of incision over a 13.5 km reach from 1969 to 1981. As a consequence of substantially increased sediment supply, approximately 2.13 m of aggradation was induced downstream of this reach during the same period. This accumulation represents a 60% recovery of bed level at the downstream site since the completion of channel work in 1969. Gradient adjustment with time is described by exponential decay functions. The length of time required for adjustment to some new quasi-equilibrium condition is computed by these decay functions and is about 20 years from the completion of channel work. Adjusted slopes are less than predisturbed values, probably because straightened channels dissipate less energy by friction, allowing more energy for sediment transport. An equivalent sediment load, therefore, can be transported at a considerably gentler slope. The predisturbed slope exceeds the adjusted slope by an order of magnitude on the downstream reach of the South Fork Forked Deer River. ?? 1987 Springer-Verlag New York Inc.

  14. Diamond cutters' grinders

    NASA Astrophysics Data System (ADS)

    Romanov, B. F.

    1985-03-01

    The development of diamond tool designs is determined by the development of the technology for the synthesis of artificial diamonds. The technology of syntehsizing artificial diamonds involves the production of mono and polycrystalline diamonds and composition diamond-containing materials. High strength and thermally stable monocrystalline diamonds brands AS30 to AS80 in a size of up to 800 micrometers, and polycrystalline diamonds: black diamonds, ballas (Synthetic Fiber) in a size up to 10mm, are manufactured. Production of single-layer and double-layer diamond plates used in cutting tools is organized. The raw materials base with the constant decrease in the use of natural diamonds is the basis for the development of the manufacture of a wide array of diamond tools. New areas of applications for tools using natural diamonds, such as diamond cutters for turning high-precision parts, straightening tools, hardness gages are outlined. Diamond cutters with natural diamonds are used to grind surfaces which have exceptionally high requirements with respect to the reflecting capacity and roughness.

  15. Reply to ''Comments on 'Why Hasn't Earth Warmed as much as Expected?'''

    NASA Technical Reports Server (NTRS)

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph A.; Ogren, John A.; Rodhe, Henning

    2012-01-01

    In response to our article, Why Hasnt Earth Warmed as Much as Expected? (2010), Knutti and Plattner (2012) wrote a rebuttal. The term climate sensitivity is usually defined as the change in global mean surface temperature that is produced by a specified change in forcing, such as a change in solar heating or greenhouse gas concentrations. We had argued in the 2010 paper that although climate models can reproduce the global mean surface temperature history over the past century, the uncertainties in these models, due primarily to the uncertainty in climate forcing by airborne particles, mean that the models lack the confidence to actually constrain the climate sensitivity within useful limits for climate prediction. Knutti and Plattner are climate modelers, and they argued essentially that because the models could reproduce the surface temperature history, the issue we raised was moot. Our response amounts to straightening out this confusion; for the models to be constraining, they must be able to reproduce the surface temperature history with sufficient confidence, not just to match the measurements, but to exclude alternative histories. As before, we concluded that if we can actually make the aerosol measurements using currently available, state-of-the-art techniques, we can determine the aerosol climate forcing to the degree required to constrain that aspect of model climate sensitivity. A technical issue relating to the timescale over which a change in CO2 emissions would be equilibrated in the environmental energy balance was also discussed, again, a matter of differences in terminology.

  16. Mechanics of biting in great white and sandtiger sharks.

    PubMed

    Ferrara, T L; Clausen, P; Huber, D R; McHenry, C R; Peddemors, V; Wroe, S

    2011-02-01

    Although a strong correlation between jaw mechanics and prey selection has been demonstrated in bony fishes (Osteichthyes), how jaw mechanics influence feeding performance in cartilaginous fishes (Chondrichthyes) remains unknown. Hence, tooth shape has been regarded as a primary predictor of feeding behavior in sharks. Here we apply Finite Element Analysis (FEA) to examine form and function in the jaws of two threatened shark species, the great white (Carcharodon carcharias) and the sandtiger (Carcharias taurus). These species possess characteristic tooth shapes believed to reflect dietary preferences. We show that the jaws of sandtigers and great whites are adapted for rapid closure and generation of maximum bite force, respectively, and that these functional differences are consistent with diet and dentition. Our results suggest that in both taxa, insertion of jaw adductor muscles on a central tendon functions to straighten and sustain muscle fibers to nearly orthogonal insertion angles as the mouth opens. We argue that this jaw muscle arrangement allows high bite forces to be maintained across a wider range of gape angles than observed in mammalian models. Finally, our data suggest that the jaws of sub-adult great whites are mechanically vulnerable when handling large prey. In addition to ontogenetic changes in dentition, further mineralization of the jaws may be required to effectively feed on marine mammals. Our study is the first comparative FEA of the jaws for any fish species. Results highlight the potential of FEA for testing previously intractable questions regarding feeding mechanisms in sharks and other vertebrates. PMID:21129747

  17. Effect of microstrain on the magnetic properties of BiFeO{sub 3} nanoparticles

    SciTech Connect

    Mocherla, Pavana S. V.; Sudakar, C.; Karthik, C.; Ubic, R.; Ramachandra Rao, M. S.

    2014-09-29

    We report on size induced microstrain-dependent magnetic properties of BiFeO{sub 3} nanoparticles. The microstrain is found to be high (ε > 0.3%) for smaller crystallite sizes (d < 30 nm), and shows a sharp decrease as the particle size increases. The presence of pseudo-cubic symmetry is evidenced for these nanoparticles. Raman spectral studies suggest straightening of the Fe-O-Fe bond angle accompanied by a decrease in FeO{sub 6} octahedral rotation for d < 65 nm. The magnetization shows a dip around 30 nm, half the size of spin cycloid length for BiFeO{sub 3}, due to a decrease in rhombohedral distortion with crystallite size. We also observe a similar trend in the T{sub N} with respect to size indicating that the microstrain plays a significant role in controlling the magnetic property of BiFeO{sub 3}.

  18. Bone grafting, corticotomy, and orthodontics: treatment of cleft alveolus in a chinese cohort.

    PubMed

    Mao, Li-Xia; Shen, Guo-Fang; Fang, Bing; Xia, Yun-Hui; Ma, Xu-Hui; Wang, Bo

    2013-11-01

    Objective : A multimodal therapy was applied to solve a set of related problems including collapse of the posterior segment, high level gingival margin of canine, and resorption of grafted bone in a cohort of Chinese youngsters with cleft lip and palate. This study aimed to evaluate the benefits of this treatment procedure. Methods : Thirty patients with unilateral cleft lip and palate were included in this prospective study. All patients had previously undergone only cleft lip and palate repair and presented with alveolar cleft and an obvious step in the gingival margin between the canine tooth and the teeth beside it. A multimodal therapy that included bone grafting, corticotomy, and orthodontics was applied to solve these problems. Grafted bone volume, parallelism of the roots, root resorption, gingival margin, and mobility of the canine on the cleft side were established before surgery, 1 week after surgery, and after straightening of the canine. Results : Less than 25% of the grafted bone was reabsorbed in 25 of the 30 patients, while less than 50% was resorbed in the remaining five. The roots of the canines on the cleft side were mostly parallel to the adjacent teeth. Root resorption and mobility of the canines were slight. The difference in the gingival margin between the canines on the cleft side and the other side was small. Conclusions : Canines moved into the grafted bone safely and effectively, thus achieving a normal gingival margin and retaining grafted bone volume in one operation. PMID:22849663

  19. Effect of a prior stretch on the aging response of an Al-Cu-Li-Ag-Mg-Zr alloy

    NASA Technical Reports Server (NTRS)

    Kumar, K. S.; Brown, S. A.; Pickens, Joseph R.

    1991-01-01

    Recently, a family of Al-Cu-Li alloys containing minor amounts of Ag, Mg, and Zr and having desirable combinations of strength and toughness were developed. The Weldalite (trademark) alloys exhibit a unique characteristic in that with or without a prior stretch, they obtain significant strength-ductility combinations upon natural and artificial aging. The ultra-high strength (approximately 690 MPa yield strength) in the peak-aged tempers (T6 and T8) were primarily attributed to the extremely fine T(sub 1) (Al2CuLi) or T(sub 1)-type precipitates that occur in these alloys during artificial aging, whereas the significant natural aging response observed is attributed to strengthening from delta prime (Al3Li) and GP zones. In recent work, the aging behavior of an Al-Cu-Li-Ag-Mg alloy without a prior stretch was followed microstructurally from the T4 to the T6 condition. Commercial extrusions, rolled plates, and sheets of Al-Cu-Li alloys are typically subjected to a stretching operation before artificial aging to straighten the extrusions and, more importantly, introduce dislocations to simulate precipitation of strengthening phases such as T(sub 1) by providing relatively low-energy nucleation sites. The goals of this study are to examine the microstructure that evolves during aging of an alloy that was stretch after solution treatment and to compare the observations with those for the unstretched alloy.

  20. Mechanism of phospho-ubiquitin induced PARKIN activation

    PubMed Central

    Wauer, Tobias; Simicek, Michal; Schubert, Alexander; Komander, David

    2016-01-01

    Summary The E3 ubiquitin ligase PARKIN (encoded by PARK2) and the protein kinase PINK1 (encoded by PARK6) are mutated in autosomal recessive juvenile Parkinsonism (AR-JP) and work together in the disposal of damaged mitochondria by mitophagy1–3. PINK1 is stabilised on the outside of depolarised mitochondria, and phosphorylates poly-ubiquitin (polyUb)4–8 as well as the PARKIN Ub-like (Ubl) domain9,10. These phosphorylation events lead to PARKIN recruitment to mitochondria, and activation by an unknown allosteric mechanism4–12. Here we present the crystal structure of Pediculus humanus PARKIN in complex with Ser65-phosphorylated ubiquitin (phosphoUb), revealing the molecular basis for PARKIN recruitment and activation. The phosphoUb binding site on PARKIN comprises a conserved phosphate pocket and harbours residues mutated in AR-JP patients. PhosphoUb binding leads to straightening of a helix in the RING1 domain, and the resulting conformational changes release the Ubl domain from the PARKIN core; this activates PARKIN. Moreover, phosphoUb-mediated Ubl release enhances Ubl phosphorylation by PINK1, leading to conformational changes within the Ubl domain and stabilisation of an open, active conformation of PARKIN. We redefine the role of the Ubl domain not only as an inhibitory13 but also as an activating element that is restrained in inactive PARKIN and released by phosphoUb. Our work opens new avenues to identify small molecule PARKIN activators. PMID:26161729

  1. The hydrological consequences of human impact in the Lublin Region

    NASA Astrophysics Data System (ADS)

    Michalczyk, Zdzisław; Mięsiak-Wójcik, Katarzyna; Sposób, Joanna; Turczyński, Marek

    2012-01-01

    The Lublin Region is an area where local transformations in the natural environment, including the hydrosphere, occur. They result from the impact of agriculture, industry as well as water supply and sewage disposal. These activities lead to changes in the water network resulting from land improvement works, channel straightening and water runoff acceleration, as well as to the formation of local, both point and diffuse sources, of water pollution. The consequences of human impact are manifested in local transformations of the quality or quantity of water resources. As a result of intense groundwater draw-off, hydrogeological conditions are transformed, which is reflected in the persistence of depression cones of varied size and depth, noticeable in the vicinity of water intakes for Lublin, Chełm, Zamość and Kraśnik. The lowering of the first-level groundwater table also occurs as a consequence of the drainage of chalk and marl mine workings in Chełm and Rejowiec, whereas in the area of the hard coal mine both shallow and deep groundwater was transformed. It is important to indicate the consequences of human impact changes of water conditions as the hydrosphere resources should be used according to the principles of sustainable development.

  2. Buckling flows - Exploring the origins and structure of turbulence

    NASA Astrophysics Data System (ADS)

    Bejan, Adrian

    1989-11-01

    Numerous natural flow phenomena exhibit geometric features that invite an analogy with the classical buckling of solid elastic columns (Euler buckling). The most striking feature of these flows is the deformation of the straight stream into a sinusoidal shape whose wavelength is unique. Only the straightening effect of solid walls or the stabilizing effects of transversal viscous diffusion and density stratification can prevent the stream from exhibiting the sinusoidal deformation. Other turbulent flow features include: the transition to turbulence in all straight and slender flows occurring when the local Reynolds number exceeds 100; the Reynold number range of 100 of the smallest eddy in a turbulent flow; the viscous sublayer with a constant thickness of order 10 appearing in turbulent flow near a straight wall; the Strouhal number for vortex shedding behind a cylinder in a cross-flow, a constant between 0.2 and 0.3; and the Colburn analogy between heat transfer and friction in a turbulent flow near a wall.

  3. Eczema-Like Psoriasiform Skin Reaction due to Brazilian Keratin Treatment

    PubMed Central

    Gavazzoni-Dias, Maria Fernanda Reis; Rochael, Mayra; Vilar, Enoï; Tanus, Aline; Tosti, Antonella

    2016-01-01

    The use of formaldehyde and formaldehyde releasers in hair-straightening formulations started in Rio de Janeiro in 2003. The technique is known as BKT, Brazilian keratin treatment. The aim of this study was to analyze the types of skin reactions presented by patients due to BKT. We describe 7 patients with severe erythema and scurf on the scalp which developed shortly after BKT. The lesions were eczema-like psoriasiform, located mainly on the scalp. Some patients also developed eczema-like lesions and pustules on the face, neck, upper arms, and upper trunk. Dermatoscopic findings included erythema, perifollicular and interfollicular scurf. The peripilar desquamation resembled the outer skin of an onion bulb. Scalp biopsies revealed psoriasiform and spongiotic psoriasiform patterns, one of them similar to anti-TNFα biologic drug psoriasiform alopecia. The possible consequences of the absorption of formaldehyde by hairdressers or clients are still to be verified by the scientific community; however, the skin and scalp reactions observed in our cases suggest a drug reaction phenomenon and not only eczemas of irritant or allergic origin. PMID:27172059

  4. Description of New Dermacentor (Acari: Ixodidae) Species from Malaysia and Vietnam.

    PubMed

    Apanaskevich, Maria A; Apanaskevich, Dmitry A

    2015-03-01

    A new tick species belonging to the genus Dermacentor Koch, 1844, namely, Dermacentor limbooliati n. sp., is described. Adults of this species are similar to those of Dermacentor auratus Supino, 1897 and Dermacentor compactus Neumann, 1901, with which it was previously confused. Males of D. limbooliati may be distinguished from those of D. auratus and D. compactus by the following suite of characters: relatively broad conscutum with slightly straightened lateral sides, conscutum widest approximately at mid-length, oval shape of pseudoscutum, central brown patch in the center of pseudoscutum broad and diffused and not continuous with central patch in posteromedian area, conscutum posterior to pseudoscutum rugose, wide and blunt internal spur on coxa I, relatively long, narrow, and pointed external spur on coxa I, numerous internal spurs on coxa IV and trochanter I with moderate and broadly triangular spur with tapering apex. Females of D. limbooliati may be distinguished from those of D. auratus and D. compactus by the following suite of characters: rounded shape of scutum, central brown patch broad and diffused in the center of scutum, relatively long alloscutum setae, genital aperture moderately narrow V-shaped with preatrial fold bulging, wide and blunt internal spur on coxa I, relatively long, narrow, and pointed external spur on coxae I and trochanter I with moderate and broadly triangular spur with tapering apex. D. limbooliati is known from Malaysia and Vietnam where the adults were collected from vegetation, Sus scrofa resting beds, a human, and clothing. The immature stages remain unknown. PMID:26336300

  5. Biaxial deformation of collagen and elastin fibers in coronary adventitia

    PubMed Central

    Chen, Huan; Slipchenko, Mikhail N.; Liu, Yi; Zhao, Xuefeng; Cheng, Ji-Xin; Lanir, Yoram

    2013-01-01

    The microstructural deformation-mechanical loading relation of the blood vessel wall is essential for understanding the overall mechanical behavior of vascular tissue in health and disease. We employed simultaneous mechanical loading-imaging to quantify in situ deformation of individual collagen and elastin fibers on unstained fresh porcine coronary adventitia under a combination of vessel inflation and axial extension loading. Specifically, the specimens were imaged under biaxial loads to study microscopic deformation-loading behavior of fibers in conjunction with morphometric measurements at the zero-stress state. Collagen fibers largely orientate in the longitudinal direction, while elastin fibers have major orientation parallel to collagen, but with additional orientation angles in each sublayer of the adventitia. With an increase of biaxial load, collagen fibers were uniformly stretched to the loading direction, while elastin fibers gradually formed a network in sublayers, which strongly depended on the initial arrangement. The waviness of collagen decreased more rapidly at a circumferential stretch ratio of λθ = 1.0 than at λθ = 1.5, while most collagen became straightened at λθ = 1.8. These microscopic deformations imply that the longitudinally stiffer adventitia is a direct result of initial fiber alignment, and the overall mechanical behavior of the tissue is highly dependent on the corresponding microscopic deformation of fibers. The microstructural deformation-loading relation will serve as a foundation for micromechanical models of the vessel wall. PMID:24092692

  6. CRYPTIC CHOICE OF CONSPECIFIC SPERM CONTROLLED BY THE IMPACT OF OVARIAN FLUID ON SPERM SWIMMING BEHAVIOR

    PubMed Central

    Yeates, Sarah E; Diamond, Sian E; Einum, Sigurd; Emerson, Brent C; Holt, William V; Gage, Matthew J G

    2013-01-01

    Despite evidence that variation in male–female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks of genetic incompatibility through hybridization, we show how salmon and trout eggs promote fertilization by conspecific sperm. Using in vitro fertilization experiments that replicate the gametic microenvironment, we find complete interfertility between both species. However, if either species’ ova were presented with equivalent numbers of both sperm types, conspecific sperm gained fertilization precedence. Surprisingly, the species’ identity of the eggs did not explain this cryptic female choice, which instead was primarily controlled by conspecific ovarian fluid, a semiviscous, protein-rich solution that bathes the eggs and is released at spawning. Video analyses revealed that ovarian fluid doubled sperm motile life span and straightened swimming trajectory, behaviors allowing chemoattraction up a concentration gradient. To confirm chemoattraction, cell migration tests through membranes containing pores that approximated to the egg micropyle showed that conspecific ovarian fluid attracted many more spermatozoa through the membrane, compared with heterospecific fluid or water. These combined findings together identify how cryptic female choice can evolve at the gamete level and promote reproductive isolation, mediated by a specific chemoattractive influence of ovarian fluid on sperm swimming behavior. PMID:24299405

  7. Cold Pad-Batch dyeing method for cotton fabric dyeing with reactive dyes using ultrasonic energy.

    PubMed

    Khatri, Zeeshan; Memon, Muhammad Hanif; Khatri, Awais; Tanwari, Anwaruddin

    2011-11-01

    Reactive dyes are vastly used in dyeing and printing of cotton fibre. These dyes have a distinctive reactive nature due to active groups which form covalent bonds with -OH groups of cotton through substitution and/or addition mechanism. Among many methods used for dyeing cotton with reactive dyes, the Cold Pad Batch (CPB) method is relatively more environment friendly due to high dye fixation and non requirement of thermal energy. The dyed fabric production rate is low due to requirement of at least twelve hours batching time for dye fixation. The proposed CPB method for dyeing cotton involves ultrasonic energy resulting into a one third decrease in batching time. The dyeing of cotton fibre was carried out with CI reactive red 195 and CI reactive black 5 by conventional and ultrasonic (US) method. The study showed that the use of ultrasonic energy not only shortens the batching time but the alkalis concentrations can considerably be reduced. In this case, the colour strength (K/S) and dye fixation (%F) also enhances without any adverse effect on colour fastness of the dyed fabric. The appearance of dyed fibre surface using scanning electron microscope (SEM) showed relative straightening of fibre convolutions and significant swelling of the fibre upon ultrasonic application. The total colour difference values ΔE (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample. PMID:21550289

  8. Wave-particle dynamics of waveform and defect evolutions in undulated nonlinear self-excited dust acoustic waves

    SciTech Connect

    Tsai, Jun-Yi; Tsai, Ya-Yi; I, Lin

    2015-01-15

    The wave-particle dynamics for the evolutions of defects and surrounding pitchfork type waveforms of a weakly disordered self-excited dust acoustic wave is experimentally investigated in an rf dusty plasma system. Particle trajectories are tracked and correlated with waveform evolution to construct an Eulerian-Lagrangian wave-particle dynamical picture. It is found that the local accumulation and depletion of particles in the wave crest and rear, respectively, determines the local crest speed, and the growth and decay of the local crest height, which in turn determine the waveform evolution. The local crest height and the focusing and defocusing of particle trajectories due to the transverse force fields from the tilted wave crest and the non-uniform crest height along the wave crest are the key factors to determine the above particle accumulation and depletion. It explains the observations such as the lower speed of smaller crests, the straightening of the leading front of the pitchfork waveform associated with the transverse motion of defect to the open side, and the vertical defect gliding in the wave frame through the detachment of the strongly kinked pitchfork branch followed by its reconnection with the trailing crest.

  9. Graphite Composite Booms with Integral Hinges

    NASA Technical Reports Server (NTRS)

    Alexander, Wes; Carlos, Rene; Rossoni, Peter; Sturm, James

    2006-01-01

    A document discusses lightweight instrument booms under development for use aboard spacecraft. A boom of this type comprises a thin-walled graphite fiber/ matrix composite tube with an integral hinge that can be bent for stowage and later allowed to spring back to straighten the boom for deployment in outer space. The boom design takes advantage of both the stiffness of the composite in tubular geometry and the flexibility of thin sections of the composite. The hinge is formed by machining windows in the tube at diametrically opposite locations so that there remain two opposing cylindrical strips resembling measuring tapes. Essential to the design is a proprietary composite layup that renders the hinge tough yet flexible enough to be bendable as much as 90 in either of two opposite directions. When the boom is released for deployment, the torque exerted by the bent hinge suffices to overcome parasitic resistance from harnesses and other equipment, so that the two sections of the hinge snap to a straight, rigid condition in the same manner as that of measuring tapes. Issues addressed in development thus far include selection of materials, out-of-plane bending, edge cracking, and separation of plies.

  10. RAPID TRANSITION OF UNCOMBED PENUMBRAE TO FACULAE DURING LARGE FLARES

    SciTech Connect

    Wang Haimin; Deng Na; Liu Chang

    2012-04-01

    In the past two decades, the complex nature of sunspots has been disclosed with high-resolution observations. One of the most important findings is the 'uncombed' penumbral structure, where a more horizontal magnetic component carrying most of Evershed flows is embedded in a more vertical magnetic background. The penumbral bright grains are locations of hot upflows and dark fibrils are locations of horizontal flows that are guided by a nearly horizontal magnetic field. On the other hand, it was found that flares may change the topology of sunspots in {delta} configuration: the structure at the flaring polarity inversion line becomes darkened while sections of peripheral penumbrae may disappear quickly and permanently associated with flares. The high spatial and temporal resolution observations obtained with the Hinode/Solar Optical Telescope provide an excellent opportunity to study the evolution of penumbral fine structures associated with major flares. Taking advantage of two near-limb events, we found that in sections of peripheral penumbrae swept by flare ribbons the dark fibrils completely disappear, while the bright grains evolve into faculae that are signatures of vertical magnetic flux tubes. The corresponding magnetic fluxes measured in the decaying penumbrae show stepwise changes temporally correlated with the flares. These observations suggest that the horizontal magnetic field component of the penumbra could be straightened upward (i.e., turning from horizontal to vertical) due to magnetic field restructuring associated with flares, which results in the transition of penumbrae to faculae.

  11. Social connection, relationships and older lesbian and gay people1

    PubMed Central

    Barrett, Catherine; Whyte, Carolyn; Comfort, Jude; Lyons, Anthony; Crameri, Pauline

    2015-01-01

    This paper presents data from a small study exploring the impacts of homophobia on the lives of older lesbian and gay Australians. Eleven in-depth interviews were conducted with older lesbians (6) and gay men (5) ranging in age from 65 to 79 years. The study found that participants’ sense of self was shaped by the dominant medical, legal and religious institutions of their youth that defined them as sick, immoral or criminal. Participants described enforced “cure” therapies, being imprisoned, having employment terminated and being disowned and disinherited by family. In this context, intimate relationships and social networks provided refuge where trust was rebuilt and sexuality affirmed. Many created safe spaces for themselves. This equilibrium was threatened with increasing age, disability and the reliance on health and social services. Participants feared a return to institutional control and a need to “straighten up” or hide their sexuality. In response, partners stepped into the role of caregiver, at times beyond their capacity and at a cost to their relationship. The study describes the importance of understanding social connections in the lives of older lesbians and gay men. It highlights the need for inclusive services to ensure that social networks are supported and that health and well-being are promoted. PMID:25544830

  12. Phoenix Stretches its Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    The Phoenix spacecraft is scheduled to begin raising its robotic arm up and out of its stowed configuration on the third Martian day, or Sol 3 (May 28, 2008) of the mission. This artist's animation, based on engineering models, shows how Phoenix will accomplish this task. First, its wrist actuator will rotate, releasing its launch-restraint pin. Next, the forearm moves up, releasing the elbow launch-restraint pin. The elbow will then move up and over in small steps, a process referred to as 'staircasing.' This ensures that the arm's protective biobarrier wrap, now unpeeled and lying to the side of the arm, will not get in the way of the arm's deployment.

    The arm is scheduled to straighten all the way out on Sol 4 (May 29, 2008), after engineers have reviewed images and telemetry data from the spacecraft showing that the biobarrier material has been cleared.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. [Plain radiographs of the spine: static and relationships between spine and pelvis].

    PubMed

    Morvan, G; Wybier, M; Mathieu, P; Vuillemin, V; Guerini, H

    2008-05-01

    Man, with his erect posture, evolves in a world subject to the laws of gravity. His spine reflects these constraints. The morphology and static of human spine and biomechanical relationships between spine and pelvis are in direct relation with bipedia. Owing to this position the pelvis widened and straightened, characteristic sagittal spinal curves appeared and the perispinal muscles were deeply reorganized. Each pelvis is characterized by an important anatomical landmark: the pelvic incidence that reflects the sagittal morphology of the pelvis. Based on this anatomical characteristic, a chain of reactions determines the more efficient equilibrium of the whole body in the sagittal plane in term of energy consumption. Incidence affects the sacral slope, which determines lumbar lordosis, which itself influences pelvic tilt, thoracic kyphosis, and even hip and knee position. All these landmarks can easily be studied on a sagittal radiograph. Knowledge of these functional relationships is essential to understand the origin of low back pain, sagittal imbalance and above all before surgical treatment of spine disorders especially when arthrodesis is considered. PMID:18535512

  14. Development of computerized method for detection of vertebral fractures on lateral chest radiographs

    NASA Astrophysics Data System (ADS)

    Kasai, Satoshi; Li, Feng; Shiraishi, Junji; Li, Qiang; Nie, Yongkang; Doi, Kunio

    2006-03-01

    Osteoporosis is one of the major public health concerns in the world. Several clinical trials indicated clearly that pharmacologic therapy for osteoporosis is effective for persons with vertebral fractures for preventing subsequent fractures. It is, therefore, important to diagnose vertebral fractures early. Although most vertebral fractures are asymptomatic, they can often be detected on lateral chest radiographs which may be obtained for other purposes. However, investigators have reported that vertebral fractures which were visible on lateral chest radiographs were underdiagnosed or underreported. Therefore, our purpose in this study was to develop a computerized method for detection of vertebral fractures on lateral chest radiographs and to assist radiologists' image interpretation. Our computerized scheme is based on the detection of upper and lower edges of vertebrae on lateral chest images. A curved rectangular area which included a number of visible vertebrae was identified. This area was then straightened such that the upper and lower edges of the vertebrae were oriented horizontally. For detection of vertebral edges, line components were enhanced, and a multiple thresholding technique followed by image feature analysis was applied to the line enhanced image. Finally, vertebral heights determined from the detected vertebral edges were used for characterizing the shape of the vertebrae and for distinguishing fractured from normal vertebrae. Our preliminary results indicated that all of the severely fractured vertebrae in a small database were detected correctly by our computerized method.

  15. Collection and collation: theory and practice of Linnaean botany.

    PubMed

    Müller-Wille, Staffan

    2007-09-01

    Historians and philosophers of science have interpreted the taxonomic theory of Carl Linnaeus (1707-1778) as an 'essentialist', 'Aristotelian', or even 'scholastic' one. This interpretation is flatly contradicted by what Linnaeus himself had to say about taxonomy in Systema naturae (1735), Fundamenta botanica (1736) and Genera plantarum (1737). This paper straightens out some of the more basic misinterpretations by showing that: (1) Linnaeus's species concept took account of reproductive relations among organisms and was therefore not metaphysical, but biological; (2) Linnaeus did not favour classification by logical division, but criticized it for necessarily failing to represent what he called 'natural' genera; (3) Linnaeus's definitions of 'natural' genera and species were not essentialist, but descriptive and polytypic; (4) Linnaeus's method in establishing 'natural' definitions was not deductive, but consisted in an inductive, bottom-up procedure of comparing concrete specimens. The conclusion will discuss the fragmentary and provisional nature of Linnaeus's 'natural method'. I will argue in particular that Linnaeus opted for inductive strategies not on abstract epistemological grounds, but in order to confer stability and continuity to the explorative practices of contemporary natural history. PMID:17893064

  16. Natural change and human impact in a present-day fluvial catchment: The Geul River, Southern Netherlands

    NASA Astrophysics Data System (ADS)

    Vandenberghe, J.; de Moor, J. J. W.; Spanjaard, G.

    2012-07-01

    The Geul River has a long history of channel straightening and bank protection, but also has several natural meandering parts. In addition, some formerly 'fixed' or 'protected' stretches of the river have been allowed to meander freely since 1988. Therefore, it represents an ideal case for evaluating the contribution of human interference to the intrinsic evolution of the river. In this paper, we compare the response of selected (not protected) reaches of the present-day river to different human modifications. The river banks were labelled as "stable", "unstable" or "erosive". As might be expected, stretches with a high sinuosity have a high percentage of erosive and unstable bank length, while low-sinuosity stretches experience hardly any erosion. The amount of lateral erosion and sedimentation in natural situations is compared with that in situations with different bank protection and stabilization types. Erosion rates may locally attain up to 2 m per year. Detailed grain-size analysis of point-bar sections enable distinction of successive fining-up sequences. Vertical aggradation rates within the point-bars are up to 0.15 m yr- 1. The highest rates are found in the youngest point-bars. Collectively, the results of this study show that when bank protection is removed, the freely meandering river creates its own specific ecosystems and retention capacity increases. Such a return to natural environmental and ecological conditions is in accordance with the objectives of the European Water Framework Directive.

  17. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

    PubMed Central

    Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

    2015-01-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons. PMID:25975937

  18. A Houdini's trick in a fly: Leg unfolding with the aid of transient hinges in an extricating Calliphora vicina (Diptera: Calliphoridae).

    PubMed

    Frantsevich, Leonid

    2016-01-01

    Legs in a fly pupa are tightly folded in Z-configuration: the femur points forward. The fly emerges from the pupa with all legs stretched backwards. How does the fly turn long femora inside the tight puparium? Flies were captured during emergence at various moments of progress out of the puparium and at once fixed in ethanol, postfixed in Bouin's solution. Specimens were ranged by the grade of progressive extrication and maturation. Legs were excised, their configurations photographed. Legs are anchored to the VIII. abdominal segment of the puparium with the pupal sheath. Some podomers were arched or buckled yet in pharate adults. At the initial moment of extrication, new buckles appeared in femora, they split femora into 2-3 subpodomers. Instead of turning the whole femur, the fly dragged through the puparium a chain of short subpodomers linked together with transient hinges. Hinges emerged in unsclerotized areas of the tubular podomer, close to sclerotized areas (juvenile sclerites). During extrication, legs were stretched passively. This process lasted for 1-3 min, initial phase - few seconds. Residual distortions were left in hind legs of free juvenile adults. Mechanics of buckling and straightening is discussed from the viewpoint of strength of materials. PMID:26795557

  19. Eczema-Like Psoriasiform Skin Reaction due to Brazilian Keratin Treatment.

    PubMed

    Gavazzoni-Dias, Maria Fernanda Reis; Rochael, Mayra; Vilar, Enoï; Tanus, Aline; Tosti, Antonella

    2016-02-01

    The use of formaldehyde and formaldehyde releasers in hair-straightening formulations started in Rio de Janeiro in 2003. The technique is known as BKT, Brazilian keratin treatment. The aim of this study was to analyze the types of skin reactions presented by patients due to BKT. We describe 7 patients with severe erythema and scurf on the scalp which developed shortly after BKT. The lesions were eczema-like psoriasiform, located mainly on the scalp. Some patients also developed eczema-like lesions and pustules on the face, neck, upper arms, and upper trunk. Dermatoscopic findings included erythema, perifollicular and interfollicular scurf. The peripilar desquamation resembled the outer skin of an onion bulb. Scalp biopsies revealed psoriasiform and spongiotic psoriasiform patterns, one of them similar to anti-TNFα biologic drug psoriasiform alopecia. The possible consequences of the absorption of formaldehyde by hairdressers or clients are still to be verified by the scientific community; however, the skin and scalp reactions observed in our cases suggest a drug reaction phenomenon and not only eczemas of irritant or allergic origin. PMID:27172059

  20. Diagnostic and therapeutic applications of water-immersion colonoscopy.

    PubMed

    Sugimoto, Shinya; Mizukami, Takeshi

    2015-06-01

    Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications. PMID:26074684

  1. Follicular and scarring disorders in skin of color: presentation and management.

    PubMed

    Madu, Pamela; Kundu, Roopal V

    2014-08-01

    Skin of color, also known as ethnic skin, is described as skin of individuals of African, Asian, Hispanic, Native-American, Middle Eastern, and Pacific Island backgrounds. Differences in hair morphology, hair grooming, cultural practices, and susceptibility to keloid scarring exist within these populations and have been implicated in hair, scalp, and skin disorders. Acne keloidalis (AK), central centrifugal cicatricial alopecia (CCCA), dissecting cellulitis of the scalp (DCS), pseudofolliculitis barbae (PFB), traction alopecia (TA), and keloids are the most prevalent follicular and scarring disorders in skin of color. They have been associated with disfigurement, permanent hair loss, emotional distress, and decreased quality of life. Hair grooming practices, such as the use of chemical relaxers, heat straightening, and tight braiding and weaving can cause scalp irritation and follicular damage and are linked to the pathogenesis of some of these conditions. Consequently, patient education and behavior modifications are integral to the prevention and management of these disorders. Scarring disorders are also of concern in ethnic populations. Keloid scarring is more prevalent in individuals of African, Asian, and Hispanic descent. The scarring alopecia CCCA is almost exclusively seen in patients of African descent. Therapeutic regimens such as intralesional corticosteroids, surgical excision, and laser therapy can be effective for these follicular and scarring disorders, but carry a risk of dyspigmentation and keloid scarring. Ethnic skin and hair may present unique challenges to the clinician, and knowledge of these differences is essential to providing quality care. PMID:24820821

  2. The Therapeutic Effects of Intracavernosal Plaque Excision in Peyronie’s Disease: A None Grafting or Tunical Excising Procedure

    PubMed Central

    Ahmadnia, Hassan; Kamalati, Ali; Younesi Rostami, Mehdi; Imani, Mohammad Mehdi; Asadpour, Amir Abbas; Hariri, Mohammad Kazem

    2016-01-01

    BACKGROUND Current surgical treatments in Peyronie’s disease are accompanied by complications such as penile shortening, loss of sensation, erectile dysfunction and recurrence of disease. The aim of this study was the evaluation of clinical results of intracavernosal plaque excision in Peyronie’s disease. METHODS The operation was performed on 35 men. It was consisted of incising the tunica albuginea parallel to the plaque and through this incision, and the plaque was removed from the inside surface without excision or replacing the underlying tunica albuginea by grafts. All patients were evaluated before and periodically within 12 months after the surgery with measurement of penile length, curvature angle in the rigidity phase, and sexual satisfaction. RESULTS The mean age of patients was 51.4±5.3 years (range 42-59 years). The angle of penile curvature was 25-45° (mean=35°). Thirty patients (86%) obtained a nearly complete straightening of penis. All patients restored their previous penile length without any disorder of sensation within the glans penis and expressed improvement of sexual activity. CONCLUSION Intracavernosal plaque excision is a simple, easy and minimal invasive method that does not result in penile shortening, loss of sensation or erectile dysfunction. In properly selected patients, this technique can lead to acceptable elimination of penile curvature and sexual satisfaction. PMID:27308243

  3. Development of origami-style solar panels for use in support of a Mars mission

    NASA Astrophysics Data System (ADS)

    Holland, Alexander; Straub, Jeremy

    2016-05-01

    This paper presents work on the development of an Origami-style solar panel technology. This approach increases a satellite's solar array's power generation surface area, given constrained space and mass. The same deployable structure (used for the solar panels) can also house a phased array on the reverse side. For a proposed Mars demonstration mission, this array is used for communications and microwave wireless power transmission. The design of the solution is presented in detail, including a discussion of the pre-deployment configuration, the deployment process, and the final configuration. The panels, prior to deployment, are folded around the square base of the spacecraft, covering all four of its sides. To deploy them, a slight circular motion can be introduced to use centrifugal force to cause each side to fold out from the side of the satellite. A simple hinge mechanism is used to interconnect the panels and inflatable tubes or wire that is designed to stiffen in a straightened orientation when electrified, are used to move the panels into their final position and provide rigidity. The efficacy of the proposed technology is considered in the context of the Martian mission. This demonstrates its mass and volume efficiency as well as the utility of the approach for enabling the mission. A qualitative analysis of the benefits and drawbacks of the approach is presented. A discussion of the technology's overall impact on mission design is presented, before concluding with a discussion of the next steps for the research.

  4. Nanostructures of Sr2+ doped BiFeO3 multifunctional ceramics with tunable photoluminescence and magnetic properties.

    PubMed

    Mandal, S K; Rakshit, T; Ray, S K; Mishra, S K; Krishna, P S R; Chandra, Amreesh

    2013-02-01

    Careful tuning of formation (calcination) temperature of Sr(2+) doped BiFeO(3) multiferroic ceramics results in tailorable particle morphologies ranging from spherical to pillar-like. Based on the minimization of Gibb's free energy approach, the dominant homogeneous mechanism for particle growth is suggested. The chemical substitution of a trivalent ion (Bi(3+)) by a divalent ion (Sr(2+)) causes the transformation of certain fraction of Fe(3+) to Fe(4+) and/or the appearance of oxygen vacancies. This has been respectively proved by the analysis of XPS and refinement of neutron diffraction data. Although significant modification in the particle morphology is observed, the crystal unit cell remains rhombohedral with a R3c space group but interesting variations in physical properties are achieved. O-vacancies induced strong and sharp photoluminescence activity in the IR region, similar to ZnO, is reported for the first time. This observation opens up a new application for multiferroic ceramics. SQUID M-H data confirms the straightening of the canted spin structure of BiFeO(3), which in turn results in magnetism similar to ferromagnetic materials. Findings of the magneto-dielectric effect are also discussed to claim the multiferroic nature of the sample. PMID:23300169

  5. Nanostructures of Sr2+ doped BiFeO3 multifunctional ceramics with tunable photoluminescence and magnetic properties

    NASA Astrophysics Data System (ADS)

    Mandal, S. K.; Rakshit, T.; Ray, S. K.; Mishra, S. K.; Krishna, P. S. R.; Chandra, Amreesh

    2013-02-01

    Careful tuning of formation (calcination) temperature of Sr2+ doped BiFeO3 multiferroic ceramics results in tailorable particle morphologies ranging from spherical to pillar-like. Based on the minimization of Gibb’s free energy approach, the dominant homogeneous mechanism for particle growth is suggested. The chemical substitution of a trivalent ion (Bi3+) by a divalent ion (Sr2+) causes the transformation of certain fraction of Fe3+ to Fe4+ and/or the appearance of oxygen vacancies. This has been respectively proved by the analysis of XPS and refinement of neutron diffraction data. Although significant modification in the particle morphology is observed, the crystal unit cell remains rhombohedral with a R3c space group but interesting variations in physical properties are achieved. O-vacancies induced strong and sharp photoluminescence activity in the IR region, similar to ZnO, is reported for the first time. This observation opens up a new application for multiferroic ceramics. SQUID M-H data confirms the straightening of the canted spin structure of BiFeO3, which in turn results in magnetism similar to ferromagnetic materials. Findings of the magneto-dielectric effect are also discussed to claim the multiferroic nature of the sample.

  6. [Peyronie's disease: state of the art and future perspectives].

    PubMed

    Gulino, G; Sasso, F; Falabella, R; Racioppi, M; Sacco, E; D'Onofrio, A; Bassi, P F

    2007-01-01

    Peyronie's disease (PD) is characterized by the onset of a fibrous plaque within the tunica albuginea of the penile corpora cavernosa, resulting in pain and bending during the erection, which can make the intercourse difficult or impossible. Evidence from literature supports the autoimmune etiology of PD, and suggests genetic and familiar conditions, penile traumatisms and history of genital tract diseases as risk factors, even though no definitive conclusions arise about the pathogenesis of the disease. Few randomized trials demonstrated that medical therapies, such as Vitamin E, Colchicine, Potassium amminobenzoate, Tamoxifen and injection therapy with Verapamil are effective in stabilizing the acute phase of the disease. Extracorporeal shock wave therapy (ESWT) and ionophoresis cannot be considered as first line or gold standard therapies. Satisfactory results have been published about Nesbit operation in large number of cases with low-stage disease, whereas plication procedures have shown significant rates of relapse. High incidence of long-term penile retraction have been reported in high-stage disease treated with plaque incision and simple graft insertion. Malleable, soft or inflatable prostheses combined with graft implant have given the best results in terms of penile straightening and lengthening and patients' satisfaction. In conclusion, the PD etiopathogenesis hasn't been clearly understood-yet, no medical therapy is fully effective; surgery remains therefore the gold standard in case of severe deformity and/or erectile dysfunction. PMID:21086391

  7. Peyronie's disease: lights and shadows.

    PubMed

    Sasso, F; Gulino, G; Falabella, R; D'Addessi, A; Sacco, E; D'Onofrio, A; Bassi, P F

    2007-01-01

    Peyronie's disease (PD) is characterized by the onset of fibrous plaque inside the tunica albuginea of the penile corpora cavernosa that can cause pain and bending during the erection, making intercourse difficult or impossible. Evidence of the literature supports the autoimmune etiology of PD and suggests genetic and familiar conditions, penile traumatisms, and a history of genital tract diseases as risk factors, but no definitive conclusions arise about the pathogenesis of the disease. Few randomized trials demonstrated that medical therapies, such as vitamin E, colchicine, potassium aminobenzoate, tamoxifen, and injection therapy with verapamil, can stabilize the acute phase of the disease. Extracorporeal shock wave therapy and iontophoresis cannot be considered first-line or gold standard therapies. Satisfactory results have been published with the Nesbit operation in large series with low-stage disease, whereas plication procedures have shown significant relapse rates. A high incidence of long-term penile retractions has been reported in high-stage disease treated with plaque incision and simple graft insertion. Malleable, soft, or inflatable prostheses combined with graft implantation have given the best results in terms of penile straightening and lengthening and patient satisfaction. In conclusion, the etiopathogenesis of PD is not yet clearly understood, no medical therapy is fully effective, and surgery remains the gold standard in patients with severe deformity and/or erectile dysfunction. PMID:17192725

  8. The mechanical deformation mechanisms in knitted fabric composites

    SciTech Connect

    Kelay, M.S.; Bader, D.L.; Reed, P.E.

    1994-12-31

    Knitted fabric composites have certain advantages over woven composites, particularly in their ability to conform to complicated contours. As a consequence, they demonstrate inferior mechanical characteristics compared to woven materials as a direct result of the presence of bent fibers. Such a knitted fabric composite made from, for example, glass fibers in a polyurethane matrix, can be used as an orthopaedic splinting bandage for immobilizing fractures of the upper and lower limbs. Relatively little research has been reported on knitted fabric composites was initiated. It was observed that knit patterns, type of fiber, size of fibers used, size of loops, coatings and lay-up procedure were all variables that could affect the structure/property relationship of knitted fabric composites. Tensile testing with optical measurement of strain was performed on knitted substrate and coated bandages in both course and wale directions. Results indicated that the knitted fabrics function as link mechanisms at the microscopic level, with knitted loops straightening and bending before the individual elements of the knitted yarn take up significant load and material deformation. Theoretical modeling of the glass knit structure, in both course and wale directions, agrees well with experimental testing.

  9. Experimental evaluation of fuel preparation systems for an automotive gas turbine catalytic combustor

    NASA Technical Reports Server (NTRS)

    Tacina, R. R.

    1977-01-01

    Spatial fuel distributions, degree of vaporization, pressure drop and air velocity profiles were measured. Three airblast injectors and an air-assist nozzle were tested. Air swirlers were used to improve the spatial fuel-air distribution. The work was done in a 12 cm tubular duct. Test conditions were: a pressure of 0.3 and 0.5 MPa, inlet air temperatures up to 800 K, air velocities of 10 20 m/s and fuel-air ratios up to 0.020. The fuel was Jet A. The best results were obtained with an airblast configuration that used multiple cones to provide high velocity air for atomization and also straightened the inlet airflow. With this configuration, uniform spatial fuel-air distributions were obtained with mixing lengths greater than 17.8 cm. In this length, vaporization of the fuel was 98.5 percent complete at an inlet air temperature of 700 K. The total pressure loss was 1.0 percent with a reference velocity of 20 m/s and 0.25 percent at 10m/s. The air velocity was uniform across the duct and no autoignition reactions were observed.

  10. Reeled tubing counter assembly and measuring method

    SciTech Connect

    Connell, M.L.

    1993-08-10

    A method is described of measuring the tubing inserted into a well which comprises the steps of: (a) providing an elongate tubing coiled on a supply reel wherein the tubing is unspooled from the reel and is subject to curvature upon unreeling; (b) guiding the tubing through a set of gripping blocks for straightening wherein the tubing is directed for entry axially of the well in which the tubing is inserted; (c) moving the tubing into the well by motion applied to the tubing through positive engagement of a drive chain in a tubing injector; (d) engaging the drive chain of the tubing injector positively with a sprocket which is rotated in proportion to movement of the drive chain; and (e) forming a string of output pulses from a pulse generator which is rotated in a fixed ratio to the sprocket engaging the drive chain so that the pulses occur in proportion to length of tubing traversing with the drive chain. An apparatus is described for inserting a tubing into a well borehole in conjunction with a tubing injector, the apparatus comprising: (a) a sprocket engaged with a drive chain of the injector to rotate in proportion to movement of the drive chain; (b) a pulse generator; (c) means connected between said pulse generator and said drive chain sprocket providing a fixed ratio so that chain motion is converted into a pulse train proportionate to chain motion.

  11. Multiaxial cyclic ratcheting in coiled tubing -- Part 1: Theoretical modeling

    SciTech Connect

    Rolovic, R.; Tipton, S.M.

    2000-04-01

    Coiled tubing is a long, continuous string of steel tubing that is used in the oil well drilling and servicing industry. Bending strains imposed on coiled tubing as it is deployed and retrieved from a well are considerably into the plastic regime and can be as high as 3%. Progressive growth of tubing diameter occurs when tubing is cyclically bent-straightened under constant internal pressure, regardless of the fact that the hoop stress imposed by typical pressure levels is well below the material's yield strength. A new incremental plasticity model is proposed in this study that can predict multiaxial cyclic ratcheting in coiled tubing more accurately than the conventional plasticity models. A new hardening rule is presented based on published experimental observations. The model also implements a new plastic modulus function. The predictions based on the new theory correlate well with experimental results presented in Part 2 of this paper. Some previously unexpected trends in coiled tubing deformation behavior were observed and correctly predicted using the proposed model.

  12. AnimoAminoMiner: Exploration of Protein Tunnels and their Properties in Molecular Dynamics.

    PubMed

    Byska, Jan; Le Muzic, Mathieu; Gröller, M Eduard; Viola, Ivan; Kozlíková, Barbora

    2016-01-01

    In this paper we propose a novel method for the interactive exploration of protein tunnels. The basic principle of our approach is that we entirely abstract from the 3D/4D space the simulated phenomenon is embedded in. A complex 3D structure and its curvature information is represented only by a straightened tunnel centerline and its width profile. This representation focuses on a key aspect of the studied geometry and frees up graphical estate to key chemical and physical properties represented by surrounding amino acids. The method shows the detailed tunnel profile and its temporal aggregation. The profile is interactively linked with a visual overview of all amino acids which are lining the tunnel over time. In this overview, each amino acid is represented by a set of colored lines depicting the spatial and temporal impact of the amino acid on the corresponding tunnel. This representation clearly shows the importance of amino acids with respect to selected criteria. It helps the biochemists to select the candidate amino acids for mutation which changes the protein function in a desired way. The AnimoAminoMiner was designed in close cooperation with domain experts. Its usefulness is documented by their feedback and a case study, which are included. PMID:26529726

  13. Hair relaxers not associated with breast cancer risk: evidence from the black women's health study.

    PubMed

    Rosenberg, Lynn; Boggs, Deborah A; Adams-Campbell, Lucile L; Palmer, Julie R

    2007-05-01

    Hair relaxers (straighteners) have been used by millions of African American women, often for many years. Relaxer ingredients can enter the body through scalp lesions and burns. Because manufacturers are not required to list all ingredients, these products may contain unknown harmful substances. We assessed hair relaxer use in relation to breast cancer incidence in the Black Women's Health Study, a nationwide follow-up study of African American women. Information on hair relaxer use was collected in 1997; 48,167 women were followed subsequently through 2003 for incident breast cancer. Incidence rate ratios of breast cancer were estimated with Cox regression. During 266,298 person-years of follow-up, 574 incident cases of breast cancer were ascertained. There were no increases in breast cancer risk associated with any categories of duration of hair relaxer use, frequency of use, age at first use, number of burns experienced during use, or type of relaxer used. The incidence rate ratio for use at least seven times a year for 20 or more years relative to use for less than a year was 0.98 (95% confidence interval, 0.78-1.39). These results suggest that hair relaxer use does not increase the incidence of breast cancer in African American women. PMID:17507635

  14. The application of polymethylene waxes as conditioning agent in hair relaxers.

    PubMed

    Vermeulen, Shani; Van Rensburg, Audrey Jansen; Van Der Merwe, Belinda; Shalvoy, Richard; Willford, Suzanne

    2004-01-01

    Hair relaxers are harsh chemical treatments that leave the hair dull, dry and limp. There is a constant need for improvement of these products to make them milder and incorporate conditioning properties. Because of the high pH of relaxer or hair straightening systems, most quaternized (conditioning) ingredients are unstable and slowly break down to release ammonia over time, having no conditioning effects by the time the consumers use them. This paper discusses the partial substitution of the fatty alcohols that are traditionally used in relaxer systems with polymethylene wax and the benefits derived from using them. The study included the investigation of synergies among the ingredients, the stabilities of the various systems and comparisons with commercially available systems. The polymethylene wax, used in combination with the mineral oil gel and phosphate salt, coats the hair during the relaxing process, leaving it shiny, soft and conditioned as opposed to the poor condition of the hair relaxed by traditional, commercially available NaOH and LiOH relaxers. An additional benefit of using polymethylene wax in relaxer systems is that the conditioning agents that are normally added to the neutralizing shampoo to repair or mask the damage as a result of the relaxing process can be omitted. PMID:15645095

  15. Determination of pre-impact occupant postures and analysis of consequences on injury outcome. Part I: a driving simulator study.

    PubMed

    Hault-Dubrulle, Audrey; Robache, Frederic; Pacaux, Marie-Pierre; Morvan, Herve

    2011-01-01

    This paper considers pre-impact vehicle maneuvers and analyzes the resulting driver motion from their comfort seating position. Part I of this work consists of analyzing the driver behavior during a crash. The study is conducted using the LAMIH driving simulator and involves 76 participants. The emergency situation is created by a truck emerging from behind a tractor on the opposite side of the road and tearing along the participant. The driver positioning throughout the simulation is recorded via five video cameras allowing view of the front scene, the driver face, feet and pedals, hands on the steering wheel and global lateral view. Data related to braking force, seat pressure, muscular activity for major groups of muscles and actions on the steering wheel are also collected. The typical response to this type of emergency event is to brace rearward into the seat and to straighten the arms against the steering wheel, or, to swerve to attempt to avoid the impacting vehicle. While turning the steering wheel, the forearm can be directly positioned on the airbag module at time of crash which represents a potential injurious situation. These positions are used in Part II to determine scenario of positions for numerical simulation of a frontal collision. PMID:21094298

  16. Variations in the colchicine-binding domain provide insight into the structural switch of tubulin

    PubMed Central

    Dorléans, Audrey; Gigant, Benoît; Ravelli, Raimond B. G.; Mailliet, Patrick; Mikol, Vincent; Knossow, Marcel

    2009-01-01

    Structural changes occur in the αβ-tubulin heterodimer during the microtubule assembly/disassembly cycle. Their most prominent feature is a transition from a straight, microtubular structure to a curved structure. There is a broad range of small molecule compounds that disturbs the microtubule cycle, a class of which targets the colchicine-binding site and prevents microtubule assembly. This class includes compounds with very different chemical structures, and it is presently unknown whether they prevent tubulin polymerization by the same mechanism. To address this issue, we have determined the structures of tubulin complexed with a set of such ligands and show that they interfere with several of the movements of tubulin subunits structural elements upon its transition from curved to straight. We also determined the structure of tubulin unliganded at the colchicine site; this reveals that a β-tubulin loop (termed T7) flips into this site. As with colchicine site ligands, this prevents a helix which is at the interface with α-tubulin from stacking onto a β-tubulin β sheet as in straight protofilaments. Whereas in the presence of these ligands the interference with microtubule assembly gets frozen, by flipping in and out the β-subunit T7 loop participates in a reversible way in the resistance to straightening that opposes microtubule assembly. Our results suggest that it thereby contributes to microtubule dynamic instability. PMID:19666559

  17. Molecular dynamics investigation of primary photoinduced events in the activation of rhodopsin.

    PubMed Central

    Saam, Jan; Tajkhorshid, Emad; Hayashi, Shigehiko; Schulten, Klaus

    2002-01-01

    Retinal cis-trans isomerization and early relaxation steps have been studied in a 10-ns molecular dynamics simulation of a fully hydrated model of membrane-embedded rhodopsin. The isomerization, induced by transiently switching the potential energy function governing the C(11)==C(12) dihedral angle of retinal, completes within 150 fs and yields a strongly distorted retinal. The most significant conformational changes in the binding pocket are straightening of retinal's polyene chain and separation of its beta-ionone ring from Trp-265. In the following 500 ps, transition of 6s-cis to 6s-trans retinal and dramatic changes in the hydrogen bonding network of the binding pocket involving the counterion for the protonated Schiff base, Glu-113, occur. Furthermore, the energy initially stored internally in the distorted retinal is transformed into nonbonding interactions of retinal with its environment. During the following 10 ns, increased mobilities of some parts of the protein, such as the kinked regions of the helices, mainly helix VI, and the intracellular loop I2, were observed, as well as transient structural changes involving the conserved salt bridge between Glu-134 and Arg-135. These features prepare the protein for major structural transformations achieved later in the photocycle. Retinal's motion, in particular, can be compared to an opening turnstile freeing the way for the proposed rotation of helix VI. This was demonstrated by a steered molecular dynamics simulation in which an applied torque enforced the rotation of helix VI. PMID:12496081

  18. Cable load sensing device

    SciTech Connect

    Beus, M.J.; McCoy, W.G.

    1996-12-31

    Apparatus for sensing the magnitude of a load on a cable as the cable is employed to support the load includes a beam structure clamped to the cable so that a length of the cable lies along the beam structure. A spacer associated with the beam structure forces a slight curvature in a portion of the length of cable under a cable no-load condition so that the portion of the length of cable is spaced from the beam structure to define a cable curved portion. A strain gauge circuit including strain gauges is secured to the beam structure by welding. As the cable is employed to support a load the load causes the cable curved portion to exert a force normal to the cable through the spacer and on the beam structure to deform the beam structure as the cable curved portion attempts to straighten under the load. As this deformation takes place, the resistance of the strain gauges is set to a value proportional to the magnitude of the normal strain on the beam structure during such deformation. The magnitude of the normal strain is manipulated in a control device to generate a value equal to the magnitude or weight of the load supported by the cable.

  19. Impact of Schematic Designs on the Cognition of Underground Tube Maps

    NASA Astrophysics Data System (ADS)

    Liu, Zheng; Li, Zhilin

    2016-06-01

    Schematic maps have been popularly employed to represent transport networks, particularly underground tube lines (or metro lines), since its adoption by the Official London Underground in early 1930s. Such maps employ straightened lines along horizontal, vertical and diagonal directions. Recently, some researchers started to argue that the distortion in such a schematization may cause big distortion and some new designs are proposed. This project aims to make a comparative analysis of such a schematic design with a new design proposed by Mark Noad in 2011, which makes use of lines along 30º and 60º directions instead of the 45º direction. Tasks have been designed for evaluating the effect of schematic designs on route planning by travellers. The participant was asked to choose the route s/he would take among two or three possible route options and then read the name of the selected transfer station. Eye-tracking technique has been employed to track the map recognition process. Total travel time is used as criterion for effectiveness; completion time and mental work cost are used for efficiency evaluation. It has been found that (1) the design of map style has significant impact on users' travel decision making, especially map distance and transfer station symbol designs, and (2) the design style of a schematic map will have great impact on the effectiveness and efficiency of map recognition.

  20. Electrostatic and Electromagnetic Resonances of the Curling probe

    NASA Astrophysics Data System (ADS)

    Arshadi, Ali; Valadbeigi, Leila; Brinkmann, Ralf Peter

    2015-09-01

    The term Active Plasma Resonance Spectroscopy denotes a class of plasma diagnostic techniques utilizing the natural ability of plasma to resonate on or near the electron plasma frequency: An electric signal in the GHz range is coupled into the plasma via a probe. The spectral response of the plasma is recorded and a mathematical model is used to find plasma parameters such as the electron density. The curling probe, recently invented by Liang et al., is a novel realization of this concept which has many practical advantages. In particular, it can be miniaturized, and flatly embedded into the chamber wall, enabling monitoring of plasma processes without perturbing them. Physically, the curling probe can be seen as a ``curled'' form of the hairpin probe. Assuming that the effect of the spiralization is negligible, this work investigates the features of a ``straightened'' curling probe by modeling it as a slot-type resonator which is in contact with the plasma. The diffraction of an incident plane wave at the slot is calculated by solving Maxwell's equations and the cold plasma model simultaneously. Electrostatic and Electromagnetic resonances are derived. Good agreement of the analytically computed resonance frequencies with the numerical results of the probe inventors is shown.

  1. An inlet/sampling duct for airborne OH and sulfuric acid measurements

    NASA Astrophysics Data System (ADS)

    Eisele, F. L.; Mauldin, R. L.; Tanner, D. J.; Fox, J. R.; Mouch, T.; Scully, T.

    1997-12-01

    An inlet assembly has been designed, tested, and used for the airborne measurements of OH and sulfuric acid. The inlet sampling duct, which incorporates a shroud connected to two nested, restricted flow ducts, slows air velocity by approximately a factor of 16 while maintaining a uniform and well-defined flow. Qualitative wind tunnel tests showed that an inlet shroud that incorporates a 3:1 inner surface and 4.5:1 outer elliptical front surface can straighten the airflow at angles of attack of up to 18°-20° with no visible signs of turbulence. Tests using a Pitot tube to scan the flow velocity profile of the restricted flow ducts showed that the shroud, coupled to inlet ducts, could slow the flow and provide a relatively flat average velocity profile across the central portion of the ducts at angles of attack up to 17°. Tests performed using a chemical tracer showed that at angles of attack where the Pitot tube measurements began to indicate slight flow instabilities (17°-24°), there was no mixing from the walls into the center of the inlet. The inlet assembly also possesses the ability to produce a fairly uniform concentration of OH in the relatively constant velocity portion of the inner duct for instrument calibration. Actual measurements of rapidly changing OH and H2SO4 provide both additional evidence of proper inlet operation and new insight into H2SO4 production and loss in and around clouds.

  2. Vortex Formation and Acceleration of a Fish-Inspired Robot Performing Starts from Rest

    NASA Astrophysics Data System (ADS)

    Devoria, Adam; Bapst, Jonathan; Ringuette, Matthew

    2009-11-01

    We investigate the unsteady flow of a fish-inspired robot executing starts from rest, with the objective of understanding the connection among the kinematics, vortex formation, and acceleration performance. Several fish perform ``fast starts,'' where the body bends into a ``C'' or ``S'' shape while turning (phase I), followed by a straightening of the body and caudal fin and a linear acceleration (phase II). The resulting highly 3-D, unsteady vortex formation and its relationship to the acceleration are not well understood. The self-propelled robotic model contains motor-driven joints with programmable motion to emulate phase II of a simplified C-start. The experiments are conducted in a water tank, and the model is constrained to 1 direction along rails. The velocity is measured using digital particle image velocimetry (DPIV) in multiple planes. Vortex boundaries are identified using the finite-time Lyapunov exponent, then the unsteady vortex circulation is computed. The thrust is estimated from the identified vortices, and correlated with the circulation and model acceleration for different kinematics.

  3. Deformation behavior of a 16-8-2 GTA weld as influenced by its solidification substructure

    SciTech Connect

    Foulds, J.R.; Moteff, J.; Sikka, V.K.; McEnerney, J.W.

    1983-07-01

    Weldment sections from formed and welded type 316 stainless steel pipe are characterized with respect to some time-independent (tensile) and time-dependent (creep) mechanical properties at temperatures between 25/sup 0/C and 649/sup 0/C. The GTA weldment, welded with 16-8-2 filler metal, is sectioned from pipe in the formed + welded + solution annealed + straightened condition, as well as in the same condition with an additional re-solution treatment. Detailed room temperature microhardness measurements on these sections before and after reannealing enable a determination of the different recovery characteristics of weld and base metal. The observed stable weld metal solidification dislocation substructure in comparison with the base metal random dislocation structure, in fact, adequately explains weld/base metal elevated temperature mechanical behavior differences from this recovery characteristic standpoint. The weld metal substructure is the only parameter common to the variety of austenitic stainless steel welds exhibiting the consistent parent/weld metal deformation behavior differences described. As such, it must be considered the key to understanding weldment mechanical behavior.

  4. Molecular and intermolecular effects in collagen fibril mechanics: a multiscale analytical model compared with atomistic and experimental studies.

    PubMed

    Marino, Michele

    2016-02-01

    Both atomistic and experimental studies reveal the dependence of collagen fibril mechanics on biochemical and biophysical features such as, for instance, cross-link density, water content and protein sequence. In order to move toward a multiscale structural description of biological tissues, a novel analytical model for collagen fibril mechanics is herein presented. The model is based on a multiscale approach that incorporates and couples: thermal fluctuations in collagen molecules; the uncoiling of collagen triple helix; the stretching of molecular backbone; the straightening of the telopeptide in which covalent cross-links form; slip-pulse mechanisms due to the rupture of intermolecular weak bonds; molecular interstrand delamination due to the rupture of intramolecular weak bonds; the rupture of covalent bonds within molecular strands. The effectiveness of the proposed approach is verified by comparison with available atomistic results and experimental data, highlighting the importance of cross-link density in tuning collagen fibril mechanics. The typical three-region shape and hysteresis behavior of fibril constitutive response, as well as the transition from a yielding-like to a brittle-like behavior, are recovered with a special insight on the underlying nanoscale mechanisms. The model is based on parameters with a clear biophysical and biochemical meaning, resulting in a promising tool for analyzing the effect of pathological or pharmacological-induced histochemical alterations on the functional mechanical response of collagenous tissues. PMID:26220454

  5. Development of the ventral body wall in the human embryo.

    PubMed

    Mekonen, Hayelom K; Hikspoors, Jill P J M; Mommen, Greet; Köhler, S Eleonore; Lamers, Wouter H

    2015-11-01

    Migratory failure of somitic cells is the commonest explanation for ventral body wall defects. However, the embryo increases ~ 25-fold in volume in the period that the ventral body wall forms, so that differential growth may, instead, account for the observed changes in topography. Human embryos between 4 and 10 weeks of development were studied, using amira reconstruction and cinema 4D remodeling software for visualization. Initially, vertebrae and ribs had formed medially, and primordia of sternum and hypaxial flank muscle primordium laterally in the body wall at Carnegie Stage (CS)15 (5.5 weeks). The next week, ribs and muscle primordium expanded in ventrolateral direction only. At CS18 (6.5 weeks), separate intercostal and abdominal wall muscles differentiated, and ribs, sterna, and muscles began to expand ventromedially and caudally, with the bilateral sternal bars fusing in the midline after CS20 (7 weeks) and the rectus muscles reaching the umbilicus at CS23 (8 weeks). The near-constant absolute distance between both rectus muscles and approximately fivefold decline of this distance relative to body circumference between 6 and 10 weeks identified dorsoventral growth in the dorsal body wall as determinant of the 'closure' of the ventral body wall. Concomitant with the straightening of the embryonic body axis after the 6th week, the abdominal muscles expanded ventrally and caudally to form the infraumbilical body wall. Our data, therefore, show that the ventral body wall is formed by differential dorsoventral growth in the dorsal part of the body. PMID:26467243

  6. Mechanical strain of alveolar type II cells in culture: changes in the transcellular cytokeratin network and adaptations.

    PubMed

    Felder, Edward; Siebenbrunner, Marcus; Busch, Tobias; Fois, Giorgio; Miklavc, Pika; Walther, Paul; Dietl, Paul

    2008-11-01

    Mechanical forces exert multiple effects in cells, ranging from altered protein expression patterns to cell damage and death. Despite undisputable biological importance, little is known about structural changes in cells subjected to strain ex vivo. Here, we undertake the first transmission electron microscopy investigation combined with fluorescence imaging on pulmonary alveolar type II cells that are subjected to equibiaxial strain. When cells are investigated immediately after stretch, we demonstrate that curved cytokeratin (CK) fibers are straightened out at 10% increase in cell surface area (CSA) and that this is accompanied by a widened extracellular gap of desmosomes-the insertion points of CK fibers. Surprisingly, a CSA increase by 20% led to higher fiber curvatures of CK fibers and a concurrent return of the desmosomal gap to normal values. Since 20% CSA increase also induced a significant phosphorylation of CK8-ser431, we suggest CK phosphorylation might lower the tensile force of the transcellular CK network, which could explain the morphological observations. Stretch durations of 5 min caused membrane injury in up to 24% of the cells stretched by 30%, but the CK network remained surprisingly intact even in dead cells. We conclude that CK and desmosomes constitute a strong transcellular scaffold that survives cell death and hypothesize that phosphorylation of CK fibers is a mechano-induced adaptive mechanism to maintain epithelial overall integrity. PMID:18708634

  7. Multiaxial fatigue analysis on reeled deepwater steel catenary risers with girth weld defects

    NASA Astrophysics Data System (ADS)

    Yang, He-zhen; Ding, Jin-hong; Li, Qing-quan; Li, Hua-jun

    2014-12-01

    In the present study, we simulated the reel-lay installation process of deepwater steel catenary risers (SCRs) using the finite element method and proposed multiaxial fatigue analysis for reeled SCRs. The reel-lay method is one of the most efficient and economical pipeline installation methods. However, material properties of reeled risers may change, especially in the weld zone, which can affect the fatigue performance. Applying finite element analysis (FEA), we simulated an installation load history through the reel, aligner, and straightener and analyzed the property variations. The impact of weld defects during the installation process, lack of penetration and lack of fusion, was also discussed. Based on the FEA results, we used the Brown-Miller criterion combined with the critical plane approach to predict the fatigue life of reeled and non-reeled models. The results indicated that a weld defect has a significant influence on the material properties of a riser, and the reel-lay method can significantly reduce the fatigue life of SCRs. The analysis conclusion can help designers understand the mechanical performance of welds during reel-lay installation.

  8. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

    NASA Astrophysics Data System (ADS)

    Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

    2015-05-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons.

  9. Two-dimensional acoustic metamaterial structure for potential image processing

    NASA Astrophysics Data System (ADS)

    Sun, Hongwei; Han, Yu; Li, Ying; Pai, Frank

    2015-12-01

    This paper presents modeling, analysis techniques and experiment of for two-Dimensional Acoustic metamaterial Structure for filtering acoustic waves. For a unit cell of an infinite two-Dimensional Acoustic metamaterial Structure, governing equations are derived using the extended Hamilton principle. The concepts of negative effective mass and stiffness and how the spring-mass-damper subsystems create a stopband are explained in detail. Numerical simulations reveal that the actual working mechanism of the proposed acoustic metamaterial structure is based on the concept of conventional mechanical vibration absorbers. It uses the incoming wave in the structure to resonate the integrated membrane-mass-damper absorbers to vibrate in their optical mode at frequencies close to but above their local resonance frequencies to create shear forces and bending moments to straighten the panel and stop the wave propagation. Moreover, a two-dimension acoustic metamaterial structure consisting of lumped mass and elastic membrane is fabricated in the lab. We do experiments on the model and The results validate the concept and show that, for two-dimension acoustic metamaterial structure do exist two vibration modes. For the wave absorption, the mass of each cell should be considered in the design. With appropriate design calculations, the proposed two-dimension acoustic metamaterial structure can be used for absorption of low-frequency waves. Hence this special structure can be used in filtering the waves, and the potential using can increase the ultrasonic imaging quality.

  10. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography.

    PubMed

    Walton, Lucy A; Bradley, Robert S; Withers, Philip J; Newton, Victoria L; Watson, Rachel E B; Austin, Clare; Sherratt, Michael J

    2015-01-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons. PMID:25975937

  11. Strategies for penile prosthesis placement in Peyronie's disease and corporal fibrosis.

    PubMed

    Yafi, Faysal A; Sangkum, Premsant; McCaslin, Ian Ross; Hellstrom, Wayne J G

    2015-04-01

    Peyronie's disease (PD) is a wound healing disorder of the tunica albuginea of the penis. PD is generally categorized into two phases: the early acute inflammatory and late chronic fibrotic. Surgical reconstruction is only recommended during the latter established phase. There are a variety of options when erections are functional. However, when erectile dysfunction is present, the gold standard treatment is the placement of an inflatable penile prosthesis with or without additional straightening procedures. General recommendations include that after implanting and inflating the cylinders, if a clinically significant curvature is present, manual modeling is performed. If a residual curve >30° remains after modeling, then various techniques, including plaque releasing incision, is the next step. Grafting can be considered if tunical defects are >2.0 cm. Causes of corporal fibrosis include complications from an infected implant such as explantation, priapism, penile trauma, and prolonged use of an intracavernosal injection agent. Implant placement in the setting of corporal fibrosis can be technically challenging. Available strategies include incision or excision of the scar, corporotomies with or without grafting, the use of cavernotomes, or other specialized dilators, implant downsizing, and transcorporeal resection. PMID:25712763

  12. Suture techniques in rhinoplasty.

    PubMed

    Gruber, Ronald P; Chang, Edward; Buchanan, Edward

    2010-04-01

    Suture techniques are an indispensable means to biologically sculpt the cartilage of the nose. Here the authors review their use in tip-plasty and present a 4-suture algorithm that allows for simple, complete control in sculpting the shape of all nasal tips in primary rhinoplasty. After a standard cephalic trim of the lateral crus leaving it 6 mm wide, one or more of the four suture techniques are applied. One of the newest techniques that has yielded excellent results is the hemi-transdomal suture, a variation of the conventional transdomal suture. This technique narrows the dome but also everts the lateral crus slightly to avoid concavities of the nostril rim. The 4-suture algorithm is useful in both the open and closed approaches. A more general use of sutures is described and referred to as the "universal horizontal mattress suture," which can be applied to remove all unwanted convexities or concavities and can be used not only to straighten the cartilage but also strengthen it. This suture has applications for the crooked septum, the collapsed lateral crus (external valve), and the collapsed internal valve, as well as for converting ear cartilage grafts into straighter, stronger grafts than previously thought possible. PMID:20206741

  13. Biodegradable polymer membrane used as septal splint.

    PubMed

    Watzinger, F; Wutzl, A; Wanschitz, F; Ewers, R; Turhani, D; Seemann, R

    2008-05-01

    The treatment of a crooked nose is one of the most challenging rhinoplastic procedures. Correction of the abnormally curved or fractured septum has been reported using mostly scoring techniques, septoplasty and submucous resection techniques; cartilaginous spreader grafts can also be sutured to the distorted septum. Extracorporal septal straightening and repositioning/refixation is another useful but difficult technique. A common problem of septal cartilaginous grafting techniques is to harvest enough straight cartilage to correct the deformity. (Other donor sites such as rib cartilage are used, but harvesting additional cartilage is a time-consuming procedure and carries the risk of donor site morbidity.) Recent studies have been published using alloplastic internal splinting of the deformed septum. The use of poly p-dioxanone foils and porous polyethylene has been suggested before. In this study, a novel grafting material, a PolyMax membrane that has potential advantages over both materials, is presented. This is a porous biodegradable polymer made out of 70:30 poly(L-lactide-co-D,L-lactide) that remains stable for at least 7 months. Poly p-dioxanone loses its stability after only 2 months, whereas porous polyethylene is a permeable material that is controversial due to possible complications in cases of membrane exposure and infection. In this preliminary report the PolyMax membrane was used successfully in 3 patients. PMID:18337063

  14. The crooked nose: the use of medial iliac crest bone graft as a supporting framework.

    PubMed

    Cil, Yakup; Ozturk, Serdar; Kocman, Atacan Emre; Isik, Selcuk; Sengezer, Mustafa

    2008-11-01

    The crooked nose is one that the vertical axis of the nose inclines from the midline. As a rule, a major septal deformity almost always accompanies to impairing breathing and aesthetic appearance. To achieve total straightening of the crooked nose, the septum must become the target of the treatment. To prevent redeviation, we used rigid bone grafts instead of flexible and relatively weak cartilage to maintain the support of the corrected deformity. Between February 2005 and July 2007, 9 patients (all male) with crooked noses underwent corrective surgery. The mean age of the patients was 21 years (range, 19-23 years). The source of the bone graft was medial side of iliac crest in all patients. The mean follow-up was 18 months, ranging from 10 to 26 months. All patients had both functional and cosmetic problems. Mean operation time was 4 hours. Airway patency was improved in all cases. The grafts did not shift in any case and did not develop unsightly irregularities over time. Absorption of the grafts was not seen in the follow-up. There were no cases of extrusion or infection. No donor site complication occurred. None of the patient required secondary surgery. A residual deviation can be obvious despite all attempts, which has no deleterious effect on patient satisfaction. This article introduces a novel technique for the correction of the crooked nose. PMID:19098567

  15. The crooked nose: principles of treatment.

    PubMed

    Cerkes, Nazim

    2011-02-01

    Correction of the crooked nose is one of the most challenging procedures in rhinoplasty. The goals of the surgery are creation of a rigid and straight cartilaginous L-strut, correction of the deviated bony structures, and improvement of the nasal airway. Curvatures of the dorsal septum can be corrected with several techniques. Spreader grafts, cartilage batten grafts, or ethmoid bone grafts can be utilized for internal stenting to straighten the dorsal deviations. The surgical treatment for a deformed caudal septum with the most predictable and successful outcome is resection and replacement with a straight septal cartilage graft. In severe deviations of septum cartilage involving both dorsal and caudal portions of the L-strut, extracorporeal reconstruction of the septal cartilage may be the required method. For correction of the deviated bony pyramid, several osteotomy methods can be employed. Medial osteotomy, low-to-low or low-to -high internal lateral osteotomy, double-level lateral osteotomies, and external lateral osteotomy are the options, depending on the deformity. Dorsal onlay grafts can provide camouflage for any residual asymmetries after septal reconstruction or can be applied for dorsal augmentation. PMID:21317122

  16. Centrifugal forming and mechanical properties of silicone-based elastomers for soft robotic actuators

    NASA Astrophysics Data System (ADS)

    Kulkarni, Parth

    This thesis describes the centrifugal forming and resulting mechanical properties of silicone-based elastomers for the manufacture of soft robotic actuators. This process is effective at removing bubbles that get entrapped within 3D-printed, enclosed molds. Conventional methods for rapid prototyping of soft robotic actuators to remove entrapped bubbles typically involve degassing under vacuum, with open-faced molds that limit the layout of formed parts to raised 2D geometries. As the functionality and complexity of soft robots increase, there is a need to mold complete 3D structures with controlled thicknesses or curvatures on multiples surfaces. In addition, characterization of the mechanical properties of common elastomers for these soft robots has lagged the development of new designs. As such, relationships between resulting material properties and processing parameters are virtually non-existent. One of the goals of this thesis is to provide guidelines and physical insights to relate the design, processing conditions, and resulting properties of soft robotic components to each other. Centrifugal forming with accelerations on the order of 100 g's is capable of forming bubble-free, true 3D components for soft robotic actuators, and resulting demonstrations in this work include an aquatic locomotor, soft gripper, and an actuator that straightens when pressurized. Finally, this work shows that the measured mechanical properties of 3D geometries fabricated within enclosed molds through centrifugal forming possess comparable mechanical properties to vacuumed materials formed from open-faced molds with raised 2D features.

  17. Anthropometric changes and fluid shifts

    NASA Technical Reports Server (NTRS)

    Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

    1974-01-01

    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

  18. NASA Tech Briefs, April 2004

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Topics covered include: Analysis of SSEM Sensor Data Using BEAM; Hairlike Percutaneous Photochemical Sensors; Video Guidance Sensors Using Remotely Activated Targets; Simulating Remote Sensing Systems; EHW Approach to Temperature Compensation of Electronics; Polymorphic Electronic Circuits; Micro-Tubular Fuel Cells; Whispering-Gallery-Mode Tunable Narrow-Band-Pass Filter; PVM Wrapper; Simulation of Hyperspectral Images; Algorithm for Controlling a Centrifugal Compressor; Hybrid Inflatable Pressure Vessel; Double-Acting, Locking Carabiners; Position Sensor Integral with a Linear Actuator; Improved Electromagnetic Brake; Flow Straightener for a Rotating-Drum Liquid Separator; Sensory-Feedback Exoskeletal Arm Controller; Active Suppression of Instabilities in Engine Combustors; Fabrication of Robust, Flat, Thinned, UV-Imaging CCDs; Chemical Thinning Process for Fabricating UV-Imaging CCDs; Pseudoslit Spectrometer; Waste-Heat-Driven Cooling Using Complex Compound Sorbents; Improved Refractometer for Measuring Temperatures of Drops; Semiconductor Lasers Containing Quantum Wells in Junctions; Phytoplankton-Fluorescence-Lifetime Vertical Profiler; Hexagonal Pixels and Indexing Scheme for Binary Images; Finding Minimum-Power Broadcast Trees for Wireless Networks; and Automation of Design Engineering Processes.

  19. Design of a new monitoring network and first testing of new biological assessment methods according to water framework directive.

    PubMed

    Sommerhäuser, Mario; Scharner, Christoph; Schimmer, Hannes; Schindler, Anna; Plantikow, Kerstin; Vietoris, Friederike

    2007-09-01

    In most European member states, more or less completely new monitoring networks and assessment methods had to be developed as basic technical tools for the implementation of the EU Water Framework Directive (WFD). In the river basin of the Stever, the largest tributary to the river Lippe (River Rhine, Northrhine-Westphalia, Germany), a WFD-monitoring network was developed, and new German biological methods for rivers, developed for the purposes of the WFD, have been applied. Like most rivers in the German lowland areas, nearly all the river courses of the Stever system are altered by hydro-morphological degradation (straightening, bank fixation, lack of canopy etc.). In 2005 and 2006, the biological quality components of macroinvertebrates, fish and macrophytes were investigated and evaluated for the assessment of the ecological status of about 50 surface water bodies within the whole Stever system. Basic physical and chemical parameters, as well as priority substances, have been analysed in the same period. In this contribution, the design of the new monitoring network, the core principles of the German biological methods, and the most important results of the pilot monitoring will be presented. As main impacts with severe effects on the faunal and floral communities, the many migration barriers and the bad quality of the river morphology could be stated. Organic pollution is no more a severe problem in the Stever. The pilot project was successfully conducted in close collaboration with the water authorities (District Government Münster) and the water association Lippeverband. PMID:17726557

  20. Siphon flows in isolated magnetic flux tubes. III - The equilibrium path of the flux-tube arch

    NASA Technical Reports Server (NTRS)

    Thomas, John H.; Montesinos, Benjamin

    1990-01-01

    It is shown how to calculate the equilibrium path of a thin magnetic flux tube in a stratified, nonmagnetic atmosphere when the flux tube contains a steady siphon flow. The equilbrium path of a static thin flux tube in an infinite stratified atmosphere generally takes the form of a symmetric arch of finite width, with the flux tube becoming vertical at either end of the arch. A siphon flow within the flux tube increases the curvature of the arched equilibrium path in order that the net magnetic tension force can balance the inertial force of the flow, which tries to straighten the flux tube. Thus, a siphon flow reduces the width of the arched equilibrium path, with faster flows producing narrower arches. The effect of the siphon flow on the equilibrium path is generally greater for flux tubes of weaker magnetic field strength. Examples of the equilibrium are shown for both isothemal and adiabatic siphon flows in thin flux tubes in an isothermal external atmosphere.

  1. Building of a composite virtual slide from contiguous tissue samples

    PubMed Central

    2014-01-01

    Background Currently available microscope slide scanners produce whole slide images at various resolutions from histological sections. Nevertheless, acquisition area and so visualization of large tissue samples are limited by the standardized size of glass slides, used daily in pathology departments. The proposed solution has been developed to build composite virtual slides from images of large tumor fragments. Materials and methods Images of HES or immunostained histological sections of carefully labeled fragments from a representative slice of breast carcinoma were acquired with a digital slide scanner at a magnification of 20×. The tiling program involves three steps: the straightening of tissue fragment images using polynomial interpolation method, and the building and assembling of strips of contiguous tissue sample whole slide images in × and y directions. The final image is saved in a pyramidal BigTiff file format. The program has been tested on several tumor slices. A correlation quality control has been done on five images artificially cut. Results Sixty tumor slices from twenty surgical specimens, cut into two to twenty six pieces, were reconstructed. A median of 98.71% is obtained by computing the correlation coefficients between native and reconstructed images for quality control. Conclusions The proposed method is efficient and able to adapt itself to daily work conditions of classical pathology laboratories. PMID:25565295

  2. Non-invasive MRI Assessments of Tissue Microstructures and Macromolecules in the Eye upon Biomechanical or Biochemical Modulation.

    PubMed

    Ho, Leon C; Sigal, Ian A; Jan, Ning-Jiun; Yang, Xiaoling; van der Merwe, Yolandi; Yu, Yu; Chau, Ying; Leung, Christopher K; Conner, Ian P; Jin, Tao; Wu, Ed X; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S; Chan, Kevin C

    2016-01-01

    The microstructural organization and composition of the corneoscleral shell (CSS) determine the biomechanical behavior of the eye, and are important in diseases such as glaucoma and myopia. However, limited techniques can assess these properties globally, non-invasively and quantitatively. In this study, we hypothesized that multi-modal magnetic resonance imaging (MRI) can reveal the effects of biomechanical or biochemical modulation on CSS. Upon intraocular pressure (IOP) elevation, CSS appeared hyperintense in both freshly prepared ovine eyes and living rat eyes using T2-weighted MRI. Quantitatively, transverse relaxation time (T2) of CSS increased non-linearly with IOP at 0-40 mmHg and remained longer than unloaded tissues after being unpressurized. IOP loading also increased fractional anisotropy of CSS in diffusion tensor MRI without apparent change in magnetization transfer MRI, suggestive of straightening of microstructural fibers without modification of macromolecular contents. Lastly, treatments with increasing glyceraldehyde (mimicking crosslinking conditions) and chondroitinase-ABC concentrations (mimicking glycosaminoglycan depletion) decreased diffusivities and increased magnetization transfer in cornea, whereas glyceraldehyde also increased magnetization transfer in sclera. In summary, we demonstrated the changing profiles of MRI contrast mechanisms resulting from biomechanical or biochemical modulation of the eye non-invasively. Multi-modal MRI may help evaluate the pathophysiological mechanisms in CSS and the efficacy of corneoscleral treatments. PMID:27561353

  3. Dynamic tricuspid valve stenosis induced with a pacemaker lead: a case report.

    PubMed

    Skoric, Bosko; Baricevic, Zeljko; Brida, Margarita; Samardzic, Jure; Jurin, Hrvoje; Milicic, Davor

    2014-01-01

    Isolated severe tricuspid valve stenosis due to an endocardial pacemaker lead is extremely rare, and is usually caused by either fibrosis of a perforated or lacerated leaflet, or fibrotic adherence between the lead and the valvular apparatus. Reported cases typically include clinical manifestations of both systemic venous stasis and low cardiac output. The case is presented of a 20-year-old female with a surgically repaired congenital heart disease who developed severe tricuspid stenosis at six years after the implantation of a DDD pacemaker. Unexpectedly, the patient had no signs of venous stasis and suffered only from exercise intolerance. Right heart catheterization under fluoroscopic guidance revealed an atrial lead forming a loop at the level of the tricuspid valve. A paradoxical inspiratory decrease in the transvalvular diastolic gradient, caused by the caudal heart motion and straightening of the loop during inspiration, was noted. Such a dynamic nature with a temporary inspiratory relief of the obstruction may explain the partial clinical presentation of tricuspid stenosis in this case. The lead was removed and the tricuspid valve repaired surgically, after which the patient's recovery was uneventful with normalization of exercise tolerance. PMID:24779342

  4. Radium-controlled hardening of bearing rings in a quenching press

    SciTech Connect

    Luebben, T.; Mayr, P.; Hoffmann, F.

    1996-12-31

    This paper deals with the development of an {open_quotes}intelligent{close_quotes} quenching press for bearing rings. In contrast to a conventional press the diameters of the rings were measured during the quenching process. In a first step of the project radius sensors have been developed and were implemented into a computer controlled quenching press. A data acquisition system records the average inner diameter of rings continuously during the whole quenching process and compares these values with control points. Resulting differences between measured radii and desired values are corrected by radius-controlled straightening operations. The quality of this concept was verified by experiments. The rings investigated were made of SAE 52100 in two sizes with two different desired values for the inner diameter (138.5 mm and 185 mm). The varying parameter was the inner start diameter with deviations from the desired value, up to 1.4 mm. The investigations showed that this new concept results in very good ring-shapes and only small deviations from the desired value of inner diameter after quenching were observed. Independent from the start deviation the authors received final deviations of maximum {+-} 0.03 mm.

  5. Incorporation of peptides in phospholipid aggregates using ultrasound.

    PubMed

    Silva, Raquel; Little, Collin; Ferreira, Helena; Cavaco-Paulo, Artur

    2008-09-01

    This study presents the highlights of ultrasonic effects on peptides incorporated on phospholipid aggregates (liposomes). These liposomes or vesicles are known as transport agents in skin drug delivery and for hair treatment. They might be a good model to deliver larger peptides into hair to restore fibre strength after hair coloration, modelling, permanent wave and/or straightening. The preparation of liposomes 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC) with peptides (LLLLK LLLLK LLLLK LLLLK; LLLLL LCLCL LLKAK AK) was made by the thin film hydration method. The LUVs (uni-lamellar vesicles) were obtained by sonication, applying different experimental conditions, such as depth (mm) and power intensity (%). Photon-correlation spectroscopy (PCS) and electronic microscopy (EM) results confirmed that the incorporation of these peptides, with different sequence of amino acids, presented differences on the diameter, zeta-potential of membrane surface and shape of liposomes. The liposomes that included peptide LLLLK LLLLK LLLLK LLLLK present an increased in zeta-potential values after using ultrasound and an "amorphous" aspect. Conversely, the liposomes that incorporated the peptide LLLLL LCLCL LLKAK AK presented a define shape (rod shape) and the potential surface of liposome did not change significantly by the use of ultrasound. PMID:18467154

  6. A micromechanics finite-strain constitutive model of fibrous tissue

    NASA Astrophysics Data System (ADS)

    Chen, Huan; Liu, Yi; Zhao, Xuefeng; Lanir, Yoram; Kassab, Ghassan S.

    2011-09-01

    Biological tissues have unique mechanical properties due to the wavy fibrous collagen and elastin microstructure. In inflation, a vessel easily distends under low pressure but becomes stiffer when the fibers are straightened to take up the load. The current microstructural models of blood vessels assume affine deformation, i.e., the deformation of each fiber is assumed to be identical to the macroscopic deformation of the tissue. This uniform-field (UF) assumption leads to the macroscopic (or effective) strain energy of the tissue that is the volumetric sum of the contributions of the tissue components. Here, a micromechanics-based constitutive model of fibrous tissue is developed to remove the affine assumption and to take into consideration the heterogeneous interactions between the fibers and the ground substance. The development is based on the framework of a recently developed second-order homogenization theory, and takes into account the waviness, orientations and spatial distribution of the fibers, as well as the material nonlinearity at finite-strain deformation. In an illustrative simulation, the predictions of the macroscopic stress-strain relation and the statistical deformation of the fibers are compared to the UF model, as well as finite-element (FE) simulation. Our predictions agree well with the FE results, while the UF predictions significantly overestimate. The effects of fiber distribution and waviness on the macroscopic stress-strain relation are also investigated. The present mathematical model may serves as a foundation for native as well as for engineered tissues and biomaterials.

  7. Performance evaluation of panoramic electro-optic imagers using the TOD method

    NASA Astrophysics Data System (ADS)

    Désaulniers, Pierre; Thibault, Simon

    2011-05-01

    The triangle orientation discrimination (TOD) method is an emerging technique for the evaluation of electro-optical (EO) systems. In this method, the test pattern is a non-periodic equilateral triangle in one of four different orientations (apex up, down, left, or right), and the measurement procedure is a robust four-alternative forced-choice psychophysical process. This leads to a time-consuming task. Consequently, software models have been developed to replace the required human observers. These models base their decision on the orientation of the target using correlation between observed data and the set of four differently oriented targets. This study investigates for the first time how this method can be applied to highly distorted OE systems like hemispheric imagers. These types of systems have inherent large distortion, but the distortion should not be considered as an aberration but rather the result of the projection of a hemispheric field (3D) on a 2D sensor. The distortion deforms the image of the targets and image processing is usually performed to remove distortion and straighten the field of view. We present a comparison in accuracy and computational burden for the evaluation of EO system performance between cases where tested images are pre-processed and correlated to unchanged triangle targets and where untouched (distorted) images are correlated with position-wise distorted targets. This is a first evaluation of the application of the TOD with the goal of obtaining an image quality criterion for panoramic imagers.

  8. Design of a decision tool for hydromorphological restoration of water bodies in Walloon Region

    NASA Astrophysics Data System (ADS)

    Lambot, Francis; de Le Court, Bernard; Petit, François; Hallot, Eric; Peeters, Alexandre; Descy, Jean-Pierre; Verniers, Gisèle; Latli, Adrien

    2010-05-01

    The pilot project WALPHY (LIFE + Environment LIFE07 ENV/B/000038, UE-funded) develops a structured approach aiming at improving hydromorphological quality of the upstream Meuse basin in order to achieve the "good ecological status" required by the Water Framework Directive (WFD 2000/60). It began in January 2009 for a period of 5 years. River's biological recovery needs the recovery of river's structure and physical dynamics. Returning to "good ecological status" inevitably involves physical restoration of affected rivers. Physical component of aquatic environment acts as a limiting factor for their functioning. Three types of modification are key obstacles for river good ecological status: (i) fluxes alteration (discharge, sedimentation…), (ii) forms alteration (uniform facies…) and (iii) biotopes access alteration (lateral connections breaks, modification of the continuity upstream/downstream…). Therefore hydromorphology is needed to implement the WFD. To respond to this legal necessity, we develop a unique, useful and suitable methodology in Walloon Region to determine and schedule river physical quality restoration works. This methodology has been applied on 3 "risk water bodies". The works are based on two axes : longitudinal continuity and transversal continuity. The two first selected water bodies (Bocq river, eastern tributary of the Meuse) seem to be convenient for the restoration works which concern the longitudinal continuity due to the presence of dams and other obstacles usually between 1 and 3 m high. These works consist in dam management (weir removal or fish passage) taking into account hydromorphological (bedload transport) and biological (invertebrate or fish species free movement) impacts. The third water bodies (Eau Blanche river, western tributary of the Meuse) presents straightened rivers with artificial banks, witch consequently own bad connections between the stream and its floodplain. This water bodies should therefore be appropriated

  9. Miniature Ion-Mobility Spectrometer

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.

    2006-01-01

    generate a moderate electric field. Positive ions leaving the membrane holes would be accelerated in this electric field. The resulting flux of ions away from the ionization membrane would create a partial vacuum that would draw more of the gas medium through the membrane. The figure depicts a filter electrode and detector electrodes located along the sides of a drift tube downstream from the accelerator electrode. These electrodes would apply a transverse AC electric field superimposed on a ramped DC electric field. The AC field would effect differential transverse dispersal of ions. At a given instant of time, the trajectories of most of the ions would be bent toward the electrodes, causing most of the ions to collide with the electrodes and thereby become neutralized. The DC field would partly counteract the dispersive effect of the AC field, straightening the trajectories of a selected species of ions; the selection would vary with the magnitude of the applied DC field. The straightening of the trajectories of the selected ions would enable them to pass into the region between the detector electrodes. Depending on the polarity of the voltage applied to the detector electrodes, the electric field between the detector electrodes would draw the selected ions to one of these electrodes. Hence, the current collected by one of the detector electrodes would be a measure of the abundance of ions of the selected species. The ramping of the filter- electrode DC voltage would sweep the selection of ions through the spectrum of ionic species.

  10. Georectification of historical aerial photos to track meander change in Wood River, Klamath County, Oregon

    NASA Astrophysics Data System (ADS)

    Nash, C.; Hughes, M. L.

    2010-12-01

    , triggering serial extension of proximal meanders. In the lower reaches, where valley slope is lower, the meander belt virtually vanishes and the river flows through levees perched over partially drained lake-fringe wetlands. Sinuosity is generally low in these reaches and, in contrast to the upper reaches, increased in several areas. This increase in sinuosity can be partially attributed to a restoration project carried out by the Bureau of Land Management that re-meandering the lower 2 miles of the river channel in 2002. The single largest channel change occurred in the transition between the upper and lower reaches, where a series of meanders where artificially straightened. Fundamental differences in the hydrogeomorphology of the Wood River in the upper (more active), middle (straightened), and lower (narrower, less active, leveed) reaches imply different opportunities and constraints for ecological river restoration. Whereas restoration in the upper river and middle reaches could emphasize promoting natural processes and patterns of river meandering, re-establishing the geohydrologic connection between the channel and adjacent wetland systems appears to be the most urgent need in the lower river.

  11. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  12. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  13. Molecular Insights into the Transmembrane Domain of the Thyrotropin Receptor

    PubMed Central

    Chantreau, Vanessa; Taddese, Bruck; Munier, Mathilde; Gourdin, Louis; Henrion, Daniel; Rodien, Patrice; Chabbert, Marie

    2015-01-01

    The thyrotropin receptor (TSHR) is a G protein-coupled receptor (GPCR) that is member of the leucine-rich repeat subfamily (LGR). In the absence of crystal structure, the success of rational design of ligands targeting the receptor internal cavity depends on the quality of the TSHR models built. In this subfamily, transmembrane helices (TM) 2 and 5 are characterized by the absence of proline compared to most receptors, raising the question of the structural conformation of these helices. To gain insight into the structural properties of these helices, we carried out bioinformatics and experimental studies. Evolutionary analysis of the LGR family revealed a deletion in TM5 but provided no information on TM2. Wild type residues at positions 2.58, 2.59 or 2.60 in TM2 and/or at position 5.50 in TM5 were substituted to proline. Depending on the position of the proline substitution, different effects were observed on membrane expression, glycosylation, constitutive cAMP activity and responses to thyrotropin. Only proline substitution at position 2.59 maintained complex glycosylation and high membrane expression, supporting occurrence of a bulged TM2. The TSHR transmembrane domain was modeled by homology with the orexin 2 receptor, using a protocol that forced the deletion of one residue in the TM5 bulge of the template. The stability of the model was assessed by molecular dynamics simulations. TM5 straightened during the equilibration phase and was stable for the remainder of the simulations. Our data support a structural model of the TSHR transmembrane domain with a bulged TM2 and a straight TM5 that is specific of glycoprotein hormone receptors. PMID:26545118

  14. Design of multi-stopband metamaterial plates for absorption of broadband elastic waves and vibration

    NASA Astrophysics Data System (ADS)

    Peng, Hao; Pai, P. F.

    2015-03-01

    This paper presents the modeling technique, working mechanism and design guidelines for acoustic multi-stopband metamaterial plates for broadband elastic wave absorption and vibration suppression. The metamaterial plate is designed by integrating two-DOF (degree of freedom) mass-spring subsystems with an isotropic plate to act as vibration absorbers. For an infinite metamaterial plate without damping, a unit cell is modeled using the extended Hamilton's principle, and two stopbands are obtained by dispersion analysis on the averaged three-DOF model. For a finite metamaterial plate with boundary conditions and damping, shear-deformable conforming plate elements are used to model the whole plate, and stopbands and their dynamic effects are investigated by frequency response analysis and transient analysis by direct numerical integration. Influences of absorbers' resonant frequencies and damping ratios, plate's boundary conditions and dimensions, and working plate-absorber modes are thoroughly investigated. Results show that the metamaterial plate is essentially based on the concept of conventional vibration absorbers. The local resonance of the two-DOF subsystems generates two stopbands, and the inertial forces generated by the resonant vibrations of absorbers straighten the plate and attenuate/stop wave propagation. Each stopband's bandwidth can be increased by increasing the absorber mass and/or reducing the isotropic plate's unit cell mass. Moreover, a high damping ratio for the secondary absorber can combine the two stopbands into one wide stopband for vibration suppression, and a low damping ratio for the primary absorber warrants absorbers' quick response to steady and/or transient excitations.

  15. Panostotic expansile bone disease with massive jaw tumor formation and a novel mutation in the signal peptide of RANK.

    PubMed

    Schafer, Anne L; Mumm, Steven; El-Sayed, Ivan; McAlister, William H; Horvai, Andrew E; Tom, Andrea M; Hsiao, Edward C; Schaefer, Frederick V; Collins, Michael T; Anderson, Mark S; Whyte, Michael P; Shoback, Dolores M

    2014-04-01

    Precise regulation of bone resorption is critical for skeletal homeostasis. We report a 32-year-old man with a panostotic expansile bone disease and a massive hemorrhagic mandibular tumor. Originally from Mexico, he was deaf at birth and became bow-legged during childhood. There was no family history of skeletal disease. Puberty occurred normally, but during adolescence he experienced difficulty straightening his limbs, sustained multiple fractures, and developed a bony tumor on his chin. By age 18 years, all limbs were misshapen. The mandibular mass grew and protruded from the oral cavity, extending to the level of the lower ribs. Other bony defects included a similar maxillary mass and serpentine limbs. Upon referral at age 27 years, biochemical studies showed serum alkaline phosphatase of 1760 U/L (Nl: 29-111) and other elevated bone turnover markers. Radiography of the limbs showed medullary expansion and cortical thinning with severe bowing. Although the jaw tumors were initially deemed inoperable, mandibular mass excision and staged partial maxillectomy were eventually performed. Tumor histopathology showed curvilinear trabeculae of woven bone on a background of hypocellular fibrous tissue. Fibrous dysplasia of bone was suspected, but there was no mutation in codon 201 of GNAS in samples from blood or tumor. His clinical and radiographic findings, elevated serum markers, and disorganized bone morphology suggested amplified receptor activator of NF-κB (RANK) signaling, even though his disorder differed from conditions with known constitutive activation of RANK signaling (eg, familial expansile osteolysis). We found a unique 12-base pair duplication in the signal peptide of TNFRSF11A, the gene that encodes RANK. No exon or splice site mutations were found in the genes encoding RANK ligand or osteoprotegerin. Alendronate followed by pamidronate therapies substantially decreased his serum alkaline phosphatase activity. This unique patient expands the

  16. Tailoring turbulence with an active grid

    NASA Astrophysics Data System (ADS)

    Cekli, Hakki Ergun; van de Water, Willem

    2010-08-01

    Using an active grid in a wind tunnel, we generate homogeneous shear turbulence and initiate turbulent boundary layers with adjustable properties. Homogeneous shear turbulence is characterized by a constant gradient of the mean velocity and a constant turbulence intensity. It is the simplest anisotropic turbulent flow thinkable, and it is generated traditionally by equipping a wind tunnel with screens which have a varying transparency and flow straighteners. This is not done easily, and the reachable turbulence levels are modest. We describe a new technique for generating homogeneous shear turbulence using an active grid only. Our active grid consists of a grid of rods with attached vanes which can be rotated by servo motors. We control the grid by prescribing the time-dependent angle of each axis. We tune the vertical transparency profile of the grid by setting appropriate angles of each rod such as to generate a uniform velocity gradient, and set the rods in flapping motion around these angles to tailor the turbulence intensity. The Taylor Reynolds number reached was R λ = 870, the shear rate S = ∂ U/∂ y = 9.2 s-1, the nondimensional shear parameter S *≡ Sq 2/ɛ = 12 and u = 1.4 ms-1. As a further application of this idea we demonstrate the generation of a simulated atmospheric boundary layer in a wind tunnel which has tunable properties. This method offers a great advantage over the traditional one, in which vortex-generating structures need to be placed in the wind tunnel to initiate a fat boundary layer.

  17. Spring-like fibers for cardiac tissue engineering.

    PubMed

    Fleischer, Sharon; Feiner, Ron; Shapira, Assaf; Ji, Jing; Sui, Xiaomeng; Daniel Wagner, H; Dvir, Tal

    2013-11-01

    Recapitulation of the cellular microenvironment of the heart, which promotes cell contraction, remains a key challenge in cardiac tissue engineering. We report here on our work, where for the first time, a 3-dimensional (3D) spring-like fiber scaffold was fabricated, successfully mimicking the coiled perimysial fibers of the heart. We hypothesized that since in vivo straightening and re-coiling of these fibers allow stretching and contraction of the myocardium in the direction of the cardiomyocytes, such a scaffold can support the assembly of a functional cardiac tissue capable of generating a strong contraction force. In this study, the mechanical properties of both spring-like single fibers and 3D scaffolds composed of them were investigated. The measurements showed that they have increased elasticity and extensibility compared to corresponding straight fibers and straight fiber scaffolds. We have also shown that cardiac cells cultivated on single spring-like fibers formed cell-fiber interactions that induced fiber stretching in the direction of contraction. Moreover, cardiac cells engineered within 3D thick spring-like fiber scaffolds formed a functional tissue exhibiting significantly improved function, including stronger contraction force (p = 0.002), higher beating rate (p < 0.0001) and lower excitation threshold (p = 0.02), compared to straight fiber scaffolds. Collectively, our results suggest that spring-like fibers can play a key role in contributing to the ex vivo formation of a contracting cardiac muscle tissue. We envision that cardiac tissues engineered within these spring-like fiber scaffolds can be used to improve heart function after infarction. PMID:23953840

  18. Surveying Cross Sections of the Kootenai River Between Libby Dam, Montana, and Kootenay Lake, British Columbia, Canada

    USGS Publications Warehouse

    Barton, Gary J.; Moran, Edward H.; Berenbrock, Charles

    2004-01-01

    The declining population of Kootenai River white sturgeon, which was listed as an Endangered Species in 1994, has prompted a recovery team to assess the feasibility of various habitat enhancement scenarios to reestablish white sturgeon populations. As the first phase in this assessment, the U.S. Geological Survey collected stream channel cross-section and longitudinal data during 2002—03 at about 400 locations along the Kootenai River from Libby Dam near Libby, Montana, to where the river empties into Kootenay Lake near Creston, British Columbia, Canada. Survey control stations with a horizontal and vertical accuracy of less than 0.1 foot were established using a global positioning system (GPS) prior to collection of stream channel cross-section data along the Kootenai River. A total of 245 cross sections were surveyed. Six cross sections upstream from Kootenai Falls were surveyed using a total station where the river was too shallow or dangerous to navigate by vessel. The remaining 239 cross sections were surveyed by interfacing real-time GPS equipment with an echo sounder to obtain bathymetric data and with a laser range- finder to obtain streambank data. These data were merged, straightened, ordered, and reduced in size to be useful. Spacing between these cross sections ranged from about 600 feet in the valley flat near Deep Creek and Shorty Island and near bridges to as much as several miles in other areas. These stream channel cross sections will provide information that can be used to develop hydraulic flow models of the Kootenai River from Libby Dam, Montana, to Queens Bay on Kootenay Lake in British Columbia, Canada.

  19. The biomechanics of race walking: literature overview and new insights.

    PubMed

    Pavei, Gaspare; Cazzola, Dario; La Torre, Antonio; Minetti, Alberto E

    2014-01-01

    This review aims to provide both researchers and coaches with a comprehensive overview of race walking biomechanics and to point out new viable route for future analyses. The examined literature has been divided into three categories according to the method of analysis: kinematics, ground reaction forces and joint power/efficiency. From an overall view, race walking athletes seem to adhere to the 'straightened knee' rule, but at race speed they do not observe the 'no-flight time' rule. The coach-oriented analysis highlights that stride length (SL) is more important than stride frequency (SF) for increasing speed and it is mainly obtained by ankle and hip joint power. Moreover, kinematic differences (SF, SL and flight time) between male and female athletes were shown. Also, we found that the maximal speed prediction according to dynamic similarity theory with walking (Froude number) is not applicable as the 3D trajectory of the body centre of mass does not follow an arc of circumference as in walking. The analysed literature shows some shortcomings: (1) the data collection is often unreliable because of the mixture of gender and performance level and (2) the analysis has sometimes been performed on a limited number of strides and speeds. These limitations lead to a scattered and incomplete gait description and a biased application of the results. The research strategy adopted so far is promising but further rigorous analyses need to be approached to obtain a fully comprehensive picture of race walking and to provide coaches with consistent results and reference values. PMID:24438531

  20. Red light regulation of ethylene biosynthesis and gravitropism in etiolated pea stems

    NASA Technical Reports Server (NTRS)

    Steed, C. L.; Taylor, L. K.; Harrison, M. A.

    2004-01-01

    During gravitropism, the accumulation of auxin in the lower side of the stem causes increased growth and the subsequent curvature, while the gaseous hormone ethylene plays a modulating role in regulating the kinetics of growth asymmetries. Light also contributes to the control of gravitropic curvature, potentially through its interaction with ethylene biosynthesis. In this study, red-light pulse treatment of etiolated pea epicotyls was evaluated for its effect on ethylene biosynthesis during gravitropic curvature. Ethylene biosynthesis analysis included measurements of ethylene; the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC); malonyl-conjugated ACC (MACC); and expression levels of pea ACC oxidase (Ps-ACO1) and ACC synthase (Ps-ACS1, Ps-ACS2) genes by reverse transcriptase-polymerase chain reaction analysis. Red-pulsed seedlings were given a 6 min pulse of 11 micromoles m-2 s-1 red-light 15 h prior to horizontal reorientation for consistency with the timeline of red-light inhibition of ethylene production. Red-pulse treatment significantly reduced ethylene production and MACC levels in epicotyl tissue. However, there was no effect of red-pulse treatment on ACC level, or expression of ACS or ACO genes. During gravitropic curvature, ethylene production increased from 60 to 120 min after horizontal placement in both control and red-pulsed epicotyls. In red-pulsed tissues, ACC levels increased by 120 min after horizontal reorientation, accompanied by decreased MACC levels in the lower portion of the epicotyl. Overall, our results demonstrate that ethylene production in etiolated epicotyls increases after the initiation of curvature. This ethylene increase may inhibit cell growth in the lower portion of the epicotyl and contribute to tip straightening and reduced overall curvature observed after the initial 60 min of curvature in etiolated pea epicotyls.

  1. By land or by sea: a modified C-start motor pattern drives the terrestrial tail-flip.

    PubMed

    Perlman, Benjamin M; Ashley-Ross, Miriam A

    2016-06-15

    Aquatic C-start escape responses in teleost fishes are driven by a well-studied network of reticulospinal neurons that produce a motor pattern of simultaneous contraction of axial muscle on the side of the body opposite the threatening stimulus, bending the fish into the characteristic C shape, followed by a traveling wave of muscle contraction on the contralateral side that moves the fish away from the threat. Superficially, the kinematics of the terrestrial tail-flip resemble the C-start, with the anterior body rolling up and over the tail into a tight C shape, followed by straightening as the fish launches off of the caudal peduncle into ballistic flight. We asked whether similar motor control is used for both behaviors in the amphibious mangrove rivulus, Kryptolebias marmoratus Fine-wire bipolar electrodes were percutaneously inserted into repeatable paired axial locations in five individual fish. Electromyograms synchronized with high-speed video were made of aquatic C-starts, immediately followed by terrestrial tail-flips. Tail-flips took longer to complete than aquatic escapes; correspondingly, muscles were activated for longer durations on land. In the tail-flip, activity was seen in contralateral posterior axial muscle for an extended period of time during the formation of the C shape, likely to press the caudal peduncle against the ground in preparation for launch. Tail-flips thus appear to be produced by modification of the motor pattern driving the aquatic C-start, with differences consistent with the additional requirement of overcoming gravity. PMID:27045097

  2. Assessing coastline exploitation from multitemporal medium-high resolution images: Jintang Island, China

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoping; Pan, Delu; Chen, Jianyu; Chen, Qi; Jia, Shifeng

    2015-10-01

    Jintang Island, located in Zhoushan archipelago New Area, China, covers an area of ~76.4 km2. As the closest island to connecting the continental shore of Zhejiang and the eastern Zhoushan Island after the project of Zhoushan Tran-Oceanic Bridges, it has experienced great change during the past 40 years, and however little attention was paid to evaluate the coastline exploitation of Jintang Island. In this paper the coastline position was firstly extracted by combining histogram thresholding and band ratio techniques with visual interpretation supplemented, based on multitemporal medium-high resolution imagery from 1970 to 2011. And then the coastline exploitation degree for different periods was quantified from three index, coastline complexity, coastline artificial intensity and coastal use. The uncertainty for coastline extraction was controlled in one-pixel for each image. The results show that the position of coastline accreted seaward since 1970. As the natural coastline was straightened, the proportion of artificial coastline has surpassed the natural coastline after 1992. Until 2011, the dominant coastline type has been changed as artificial coastline, mainly covering urban/industrial and port coast. The calculated coastline exploitation degree of Jintang Island in 1970, 1992, 2003 and 2011 is 0.637, 0.719, 0.734 and 0.929 respectively, showing an uptrend. Part 1, 3, 4, 5, 7 and 8 of the total coastline are relatively higher than other parts, and this generally coincides with the distribution of deep ports. It indicates that natural conditions and human policies may contribute to increasing coastline exploitation from 1970 to 2011. And Jintang Island is facing great human intervention for reclaiming more coastal land to develop the marine economy.

  3. Final data report: Plenum-Nozzle Flow Characteristics Experiment

    SciTech Connect

    Duignan, M.R.; May, C.P.

    1993-09-01

    A database was developed for the flow of water through a scaled nozzle of a Savannah River Site (SRS) reactor inlet plenum. The water flow in the nozzle was such that it ranged from stratified to water-solid conditions. Data on the entry of air into the nozzle and plenum as a function of water flow are of interest in loss-of-coolant studies. The scaled nozzle was 0.44 m long, had an entrance diameter of 0.095 m, an exit opening of 0.058 m {times} 0.356 m, and an exit hydraulic diameter approximately equal to that of the inlet. Within the nozzle were three flow-straightening vanes which divided the flow path into four channels. This report includes all of the data taken for the first phase of the Plenum-Nozzle and Cold-Leg Vertical Process-Pipe Flow Characteristics Experiments: Plenum-Nozzle Experiment. Those data include daily reference checks, to determine proper operation of all instrumentation before the experiment was run, and the actual data themselves in engineering units. Not included are the videographic data which are available for each test run. However, there are four (4) 3/4 in. -video tapes of visual data and the specific tape and the location on that tape are indicated for each test run on the data sheets. The database is from sixteen test modes (e.g., flow direction, location of pipe break, air-water or just water, single nozzle or three nozzle). The flow rates ranged to approximately 320 gpm ({approx}10 kgpm prototypic) for both air and water. All data were taken at steady-state, isothermal (300 K{plus_minus}1.5 K), and atmospheric pressure conditions.

  4. Simultaneous recording of the field-EPSP as well as the population spike in the CA1 region in freely moving rats by using a fixed "double"-recording electrode.

    PubMed

    Scherf, Thomas; Frey, Julietta U; Frey, Sabine

    2010-04-30

    The recording of field potentials in freely moving rats is a very appropriate and commonly used method to describe changes in cellular mechanisms underlying synaptic plasticity. Recently, we introduced a method for the simultaneous recording of both the field-EPSP as well as the population spike in the dentate gyrus of freely moving rats. We used self-made "double"-recording electrodes, consisting of two wires straighten together with a constant distance between both tips. This method was now further developed to obtain stable long-term recordings of CA1 field potentials. Rats were chronically implanted with a bipolar recording electrode; one tip of which reached the stratum radiatum to record the field-EPSP, the other tip was lowered into the stratum pyramidale of the same neuron population to record the population spike by stimulation of the contralateral CA3 (cCA3). In such prepared rats, simultaneously recorded field-EPSP as well as the population spike where thus obtained from their places of generation in a very reliable manner. This kind of preparation allowed a better standardization of stimulation intensities between different animals and stable electrophysiological recordings of both CA1-potentials over a time period of at least 24h in freely behaving animals. Furthermore, primed burst stimulation of the cCA3 (a single biphasic priming pulse was followed by a burst of 10 pulses (frequency of 100 Hz) 190 ms later; pulse duration per half-wave: 0.1 ms) resulted in an early-LTP of both measured parameters, the field-EPSP and the population spike in the CA1 region of freely moving rats. PMID:20105443

  5. Laser-based gluing of diamond-tipped saw blades

    NASA Astrophysics Data System (ADS)

    Hennigs, Christian; Lahdo, Rabi; Springer, André; Kaierle, Stefan; Hustedt, Michael; Brand, Helmut; Wloka, Richard; Zobel, Frank; Dültgen, Peter

    2016-03-01

    To process natural stone such as marble or granite, saw blades equipped with wear-resistant diamond grinding segments are used, typically joined to the blade by brazing. In case of damage or wear, they must be exchanged. Due to the large energy input during thermal loosening and subsequent brazing, the repair causes extended heat-affected zones with serious microstructure changes, resulting in shape distortions and disadvantageous stress distributions. Consequently, axial run-out deviations and cutting losses increase. In this work, a new near-infrared laser-based process chain is presented to overcome the deficits of conventional brazing-based repair of diamond-tipped steel saw blades. Thus, additional tensioning and straightening steps can be avoided. The process chain starts with thermal debonding of the worn grinding segments, using a continuous-wave laser to heat the segments gently and to exceed the adhesive's decomposition temperature. Afterwards, short-pulsed laser radiation removes remaining adhesive from the blade in order to achieve clean joining surfaces. The third step is roughening and activation of the joining surfaces, again using short-pulsed laser radiation. Finally, the grinding segments are glued onto the blade with a defined adhesive layer, using continuous-wave laser radiation. Here, the adhesive is heated to its curing temperature by irradiating the respective grinding segment, ensuring minimal thermal influence on the blade. For demonstration, a prototype unit was constructed to perform the different steps of the process chain on-site at the saw-blade user's facilities. This unit was used to re-equip a saw blade with a complete set of grinding segments. This saw blade was used successfully to cut different materials, amongst others granite.

  6. Utilization of bio-degradable fermented tapioca to synthesized low toxicity of carbon nanotubes for drug delivery applications

    NASA Astrophysics Data System (ADS)

    Nurulhuda, I.; Poh, R.; Mazatulikhma, M. Z.; Salman, A. H. A.; Haseeb, A. K.; Rusop, M.

    2016-07-01

    Carbon nanotubes (CNT) have potential biomedical applications, and investigations are shifting towards the production of such nanotubes using renewable natural sources. CNTs were synthesized at various temperatures of 700, 750, 800, 850 and 900 °C, respectively, using a local fermented food known as "tapai ubi" or fermented tapioca as a precursor. The liquid part of this fermented food was heated separately at 80°C and channeled directly into the furnace system that employs the thermal chemical vapor deposition (CVD) method. Ferrocene, which was the catalyst was placed in furnace 1 in the thermal CVD process. The resulting CNTs produced from the process were studied using field emission scanning electron microscopy (FESEM) and raman spectroscopy. The FESEM images showed the growth morphology of the CNTs at the different temperatures employed. It was observed that the higher the synthesis temperature up to a point, the diameter of CNTs produced, after which the diameter increased. CNTs with helical structures were observed at 700 °C with a diameter range of 111 - 143 nm. A more straightened structure was observed at 750 °C with a diameter range of 59 - 121 nm. From 800 °C onwards, the diameters of the CNTs were less than 60 nm. Raman analysis revealed the present of D, G and G' peak were observed at 1227-1358, 1565-1582, and 2678-2695 cm-1, respectively. The highest degree of crystallity of the carbon nanotubes synthesized were obtained at 800 °C. The radial breathing mode (RBM) were in range between 212-220 and 279-292 cm-1. Carbon nanotubes also being functionalized with Polyethylene bis(amine) Mw2000 (PEG 2000-NH2) and showed highly cells viability compared to non-functionalized CNT. The nanotubes synthesized will be applied as drug delivery in future study.

  7. [Biomechanical principles of diarthroses and synarthroses. III: Mechanical aspects of the tibiofemoral joint and role of the cruciate ligaments].

    PubMed

    Nägerl, H; Kubein-Meesenburg, D; Cotta, H; Fanghänel, J

    1993-01-01

    The tibiofemoral joint (TFJ) is force-locked. It takes its function as it is compressively loaded. The geometrical shape of the articulating surfaces and the acting force system (given by muscles and gravity) determine the kinematics as well as the quality and extent of static stability of the knee. The mechanism of the TFJ is derived from the anatomical shape of the articulating surfaces. In antero-posterior direction the joint guidance is structurally given by a stretched and overlapped dimeric link chain in lateral and medial region, respectively. Altogether, the two chains are linked up to a four-bar-chain (link quadrangle) that solely allows the tibia to strike backwards. The extent of individual extension can be rejected to morphological data of the femoral condylus. In squat position the extent of mechanical stability of the joint can be changed and even reversed to instability by a rotation of the resulting compressive joint force around the momentary rotational axis of the gear system while the joint position remains unaltered. Thus e.g. the process of straightening up is structurally explained. The cruciate ligaments do not bear any direct mechanical guiding function. They represent a sensor system which structurally resembles a mechanical bridge circuit. Beside detecting the degree of flexion it is able to monitor the indispensable contacting of the articulating surfaces. The menisci represent an additional, similarly working sensor system. At first approximation these two sensor systems are aligned in two planes which are perpendicular. Therefore they form a spatial sensor system. The presented theory is derived from mechanical, morphological, and physiological findings and gets evidence by measurements on knee loads during seated cycling. PMID:8256484

  8. Associational resistance, gall-fly preferences, and a stem dimorphism in Solidago altissima

    NASA Astrophysics Data System (ADS)

    Wise, Michael J.; Yi, Ceal G.; Abrahamson, Warren G.

    2009-05-01

    In most populations of Solidago altissima, a small proportion of plants have a growth pattern in which the stem bends early in the season so that the apex is pointing downward (i.e., a "candy-cane" stem) then straightens up again later in the season. The majority of plants, however, do not show this pattern. Instead their stems remain erect from emergence through flowering and senescence. It has recently been shown that the candy-cane stems are a result of a ducking strategy that reduces the risk of attack by apex-attacking herbivores. With such a resistance advantage, it is unclear why the candy-cane morphology is always in the minority, and why the erect morphology persists at all in S. altissima populations. In this study, we tested the hypothesis that the advantage of ducking is inversely frequency dependent and thus will not be an effective resistance strategy when ducking plants are in the majority. In a series of trials, we introduced gall flies ( Eurosta solidaginis) into enclosures with relatively low (15%) and relatively high (85%) frequencies of candy-cane versus erect stems. Candy-cane stems were more resistant than erect stems regardless of relative frequency; thus, the hypothesis was rejected. Overall, attack rates were lower for both stem types in the high candy-cane frequency groups than in the low candy-cane frequency groups. This frequency-dependent attack rate suggests that erect-stemmed plants gain "associational resistance" by having a majority of candy-cane neighbors, while candy-cane plants suffer from "associational susceptibility" when surrounded by erect-stemmed neighbors.

  9. Magnetic anisotropy and organization of nanoparticles in heads and antennae of neotropical leaf-cutter ants, Atta colombica

    NASA Astrophysics Data System (ADS)

    Alves, Odivaldo C.; Srygley, Robert B.; Riveros, Andre J.; Barbosa, Marcia A.; Esquivel, Darci M. S.; Wajnberg, Eliane

    2014-10-01

    Oriented magnetic nanoparticles have been suggested as a good candidate for a magnetic sensor in ants. Behavioural evidence for a magnetic compass in neotropical leaf-cutter ants, Atta colombica (Formicidae: Attini), motivated a study of the arrangement of magnetic particles in the ants’ four major body parts by measuring the angular dependence of the ferromagnetic resonance spectra at room temperature. Spectra of the thoraces and those of the abdomens showed no significant angular dependence, while those of the antennae and those of the heads exhibited a periodic dependence relative to the magnetic field. Fitting of the angular dependence of the resonant field resulted in an unexpected magnetic anisotropy with uniaxial symmetry. High values of the first order anisotropy constant were observed for the magnetic material in antennae (-2.9  ×  105 erg cm-3) and heads (-1  ×  106 erg cm-3) as compared to body parts of other social insects. In addition, the magnitude of the anisotropy in the heads was comparable to that observed in magnetite nanoparticles of 4-5 nm diameter. For the antennae, the mean angle of the particles’ easy magnetization axis (EA) was estimated to be 41° relative to the straightened antenna’s long axis. For the heads, EA was approximately 60° relative to the head’s axis running from midway between the spines to the clypeus. These physical characteristics indicate organized magnetic nanoparticles with a potential for directional sensitivity, which is an important feature of magnetic compasses.

  10. Influence of Friction Resistance on Expression of Superelastic Properties of Initial NiTi Wires in "Reduced Friction" and Conventional Bracket Systems.

    PubMed

    Reznikov, Natalie; Har-Zion, Gilad; Barkana, Idit; Abed, Yosef; Redlich, Meir

    2010-01-01

    Objectives. The aim of this study was to assess the influence of resistance to sliding on expression of superelastic properties of NiTi wires. Methods and Materials. A three-point bending test was performed for 0.014 NiTi wire engaged in self-ligating (Damon, SmartClip, In-Ovation) and conventional brackets (Victory) ligated with regular and reduced friction modules (Slide). The wire was deflected in the buccal direction and allowed to straighten. The maximum load, unloading plateau and unloading capacity were registered. Results. The lowest activation load was required in the active self-ligating group (In-Ovation 2.2 ± 0.4 N) and reduced friction module group (Victory/Slide 2.9 ± 0.4 N), followed by the passive self-ligating systems (Damon 3.6 ± 0.7 N, SmartClip 3.7 ± 0.4 N). Higher activation load was obtained in the conventionally ligated group (Victory/module 4.5 ± 0.4 N). Unloading plateau phase with the load magnitude ranging from 1.27 ± 0.4 N (In-Ovation) to 1.627 ± 0.4 N (Slide) was distinct in all groups but one (Victory). Conclusions. Higher friction at flanking points reduces the net force delivered by the wire. Unloading plateau phase of NiTi load-deflection curve disappears in the conventionally ligated group thus indicating to an incomplete expression of NiTi superelastic properties. A rigid passive bracket clip amplifies resistance to sliding in an active configuration and produces a permanent deflection of the wire. PMID:20981153

  11. Determination of pre-impact occupant postures and analysis of consequences on injury outcome--part II: biomechanical study.

    PubMed

    Hault-Dubrulle, Audrey; Robache, Frederic; Drazetic, Pascal; Guillemot, Herve; Morvan, Herve

    2011-01-01

    This paper considers pre-impact vehicle maneuvers and analyzes the resulting driver motion from their comfort seating position. Part I of this work consisted of analyzing the driver behavior during a simulated crash in a car driving simulator. The configuration of the virtual accident led to an unavoidable frontal crash with a truck. The typical response to this type of emergency event was to brace rearward into the seat and to straighten the arms against the steering wheel, or, to swerve to attempt to avoid the impacting vehicle. In a turn crossover maneuvers, the forearm is directly positioned on the airbag module at time of crash. This position represents a potential injurious situation and is investigated in this Part II. Static airbag-deployment tests were realized in collaboration with Zodiac using conventional airbag (sewn cushion, pyrotechnical system and open event) and a Hybrid III 50th Male Dummy seated with the left arm positioned in the path of the deploying airbag. These experiments were numerically reproduced with Madymo and the ellipsoid Hybrid III dummy model. The dummy arm interaction with airbag was correlated with experiments. Then, a numerical simulation of a frontal collision at 56 km/h was realized. The results of the computational runs put forward injurious situations when the driver's arm was in front of the steering wheel. Indeed, in this case, the arm could hit the head under airbag deployment and induced serious neck bending and violent head launching. To mitigate head and neck trauma in this out-of-position situation, an airbag prototype (bonded cushion, two pure helium cold gas generators allowing mono- or multi-stage inflating, patented silicone membrane) was proposed by Zodiac. The results of static airbag-deployment tests with conventional and prototype airbags showed a significant reduction of the maximum linear head acceleration and neck bending with airbag prototype when a dual stage inflating was ignited, due to a reduced

  12. Geometrical characteristics after Y-stenting of the basilar bifurcation

    PubMed Central

    Sağlam, Muzaffer; Kızılkılıç, Osman; Anagnostakou, Vania; Yıldız, Bülent; Koçer, Naci; Işlak, Civan

    2015-01-01

    PURPOSE We aimed to investigate the angular changes after Y-stenting of the basilar bifurcation aneurysms. METHODS A total of 19 patients (age range, 27–80 years; mean age, 52.5 years) underwent Y-stent coiling for basilar bifurcation aneurysm. Three vascular angles (α, β1, β2) were measured in the anteroposterior plane. β1 and β2 represented the angles between the basilar artery and the proximal P1 segments of the right and left posterior cerebral arteries, respectively. α represented the complementary angle between the β1 and β2 angles. Angles were measured before and after stent deployment. Diameters of the basilar artery and P2 segment of the posterior cerebral artery were measured at both sides. Correlation between vascular diameter and angular change of the basilar bifurcation was investigated. RESULTS Statistically significant α, β1, and β2 angle changes were found after stent deployment (P < 0.001). There was no statistically significant relationship between the diameter of the basilar artery and the α, β1, β2 angle changes (P > 0.05). There was no statistically significant relationship between the diameter of the posterior cerebral artery and the β angle change (P > 0.05). We found a statistically significant inverse correlation between pre-stent β angle and post-stent angle change (right side, P = 0.008; left side, P < 0.001). CONCLUSION Y-stenting narrows the effective neck and straightens the vascular bifurcation angle. Most of the angular remodeling occurs on the side that had a more acute angle before stent deployment. PMID:26359879

  13. From deposition to erosion: Spatial and temporal variability of sediment sources, storage, and transport in a small agricultural watershed

    NASA Astrophysics Data System (ADS)

    Florsheim, J. L.; Pellerin, B. A.; Oh, N. H.; Ohara, N.; Bachand, P. A. M.; Bachand, S. M.; Bergamaschi, B. A.; Hernes, P. J.; Kavvas, M. L.

    2011-09-01

    The spatial and temporal variability of sediment sources, storage, and transport were investigated in a small agricultural watershed draining the Coast Ranges and Sacramento Valley in central California. Results of field, laboratory, and historical data analysis in the Willow Slough fluvial system document changes that transformed a transport-limited depositional system to an effective erosion and transport system, despite a large sediment supply. These changes were caused by a combination of factors: (i) an increase in transport capacity, and (ii) hydrologic alteration. Alteration of the riparian zone and drainage network pattern during the past ~ 150 years included a twofold increase in straightened channel segments along with a baselevel change from excavation that increased slope, and increased sediment transport capacity by ~ 7%. Hydrologic alteration from irrigation water contributions also increased transport capacity, by extending the period with potential for sediment transport and erosion by ~ 6 months/year. Field measurements document Quaternary Alluvium as a modern source of fine sediment with grain size distributions characterized by 5 to 40% fine material. About 60% of an upland and 30% of a lowland study reach incised into this deposit exhibit bank erosion. During this study, the wet 2006 and relatively dry 2007 water years exhibited a range of total annual suspended sediment load spanning two orders of magnitude: ~ 108,500 kg/km 2/year during 2006 and 5,950 kg/km 2/year during 2007, only 5% of that during the previous year. Regional implications of this work are illustrated by the potential for a small tributary such as Willow Slough to contribute sediment - whereas large dams limit sediment supply from larger tributaries - to the Sacramento River and San Francisco Bay Delta and Estuary. This work is relevant to lowland agricultural river-floodplain systems globally in efforts to restore aquatic and riparian functions and where water quality

  14. Flux Transfer Events Simultaneously Observed by Polar and Cluster: Flux Rope in the Subsolar Region and Flux Tube Addition to the Polar Cusp

    NASA Technical Reports Server (NTRS)

    Le, G.; Zheng, Y.; Russell, C. T.; Pfaff, R. F.; Lin, N.; Slavin, J. A.; Parks, G.; Wilber, M.; Petrinec, S. M.; Lucek, E. A.; Reme, H.

    2007-01-01

    The phenomenon called flux transfer events (FTEs) is widely accepted as the manifestation of time-dependent reconnection. In this paper, we present observational evidence of a flux transfer event observed simultaneously at low-latitude by Polar and at high-latitude by Cluster. This event occurs on March 21, 2002, when both Cluster and Polar are located near local noon but with a large latitudinal separation. During the event, Cluster is moving outbound from the polar cusp to the magnetosheath, and Polar is in the magnetosheath near the equatorial magnetopause. The observations show that a flux transfer event occurs between the equator and the northern cusp. Polar and Cluster observe the FTE s two open flux tubes: Polar encounters the southward moving flux tube near the equator; and Cluster the northward moving flux tube at high latitude. The low latitude FTE appears to be a flux rope with helical magnetic field lines as it has a strong core field and the magnetic field component in the boundary normal direction exhibits a strong bi-polar variation. Unlike the low-latitude FTE, the high-latitude FTE observed by Cluster does not exhibit the characteristic bi-polar perturbation in the magnetic field. But the plasma data clearly reveal its open flux tube configuration. It shows that the magnetic field lines have straightened inside the FTE and become more aligned to the neighboring flux tubes as it moves to the cusp. Enhanced electrostatic fluctuations have been observed within the FTE core, both at low- and high-latitudes. This event provides a unique opportunity to understand high-latitude FTE signatures and the nature of time-varying reconnection.

  15. Geomorphic Effects of Engineered Log Jams in River Restoration, Middle Fork John Day River

    NASA Astrophysics Data System (ADS)

    Duffin, J.; McDowell, P. F.

    2014-12-01

    The Middle Fork of the John Day River (MFJD) Intensively Monitored Watershed in eastern Oregon is a multi-phase restoration implementation and monitoring project. MFJD is a tributary to the Colombia and is part of one of the longest free flowing rivers systems in the continental United States. It is a gravel and cobble bed river with a drainage area of 2,100 km2. The river has endured extensive channel and floodplain degradation from years of channel alteration and straightening due to human influences including dredge mining, ranching, and farming. As part of the river restoration project on the MFJD, engineered log jams have been constructed to address many of the restoration goals including creating scour pools, inhibiting bank erosion, creating and maintaining a sinuous river planform, and increasing complexity of fish habitat. There is a need for more detailed understanding on ELJ channel morphologic effects and how site-specific characteristics and differences in log jam infrastructure interact to create the in-channel features over timescales longer than a few years. This study uses detailed channel bed topographic surveys collected either with a total station or RTK-GPS technology. Geomorphic change detection techniques are utilized to monitor topographic change under and around the 26 log structures in two different river reaches over a six to seven year period The log structures are often associated with deepening of pools as desired, but also some structures show sedimentation under the structure. Differences in the patterns will be assessed based on the design, location, and specific characteristics of the log structures; variables include number and placement of logs, volume of structure, location on meander bend, and sediment sizes.

  16. Functional properties of an isolated. cap alpha beta. heterodimeric human placenta insulin-like growth factor 1 receptor complex

    SciTech Connect

    Feltz, S.M.; Swanson, M.L.; Wemmie, J.A.; Pessin, J.E.

    1988-05-03

    Treatment of human placenta membranes at pH 8.5 in the presence of 2.0 mM dithiothreitol (DTT) for 5 min, followed by the simultaneous removal of the DTT and pH adjustment of pH 7.6, resulted in the formation of a functional ..cap alpha beta.. heterodimeric insulin-like growth factor 1 (IGF-1) receptor complex from the native ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state. The membrane-bound ..cap alpha beta.. heterodimeric complex displayed similar curvilinear /sup 125/I-IGF-1 equilibrium binding compared to the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric complex. /sup 125/I-IGF-1 binding to both the isolated ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta.. heterodimeric complexes demonstrated a marked straightening of the Scatchard plots, compared to the placenta membrane-bound IGF-1 receptors, with a 2-fold increase in the high-affinity binding component. IGF-1 stimulation of IGF-1 receptor autophosphorylation indicated that the ligand-dependent activation of ..cap alpha beta.. heterodimeric protein kinase activity occurred concomitant with the reassociation into a covalent ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric state. These data demonstrate that (i) a combination of alkaline pH and DTT treatment of human placenta membranes results in the formation of an ..cap alpha beta.. heterodimeric IGF-1 receptor complex, (ii) unlike the insulin receptor, high-affinity homogeneous IGF-1 binding occurs in both the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta.. heterodimeric complexes, and (iii) IGF-1-dependent autophosphorylation of the ..cap alpha beta.. heterodimeric IGF-1 receptor complex correlates wit an IGF-1 dependent covalent reassociation into an ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state.

  17. Magnetic resonance imaging of the endophenotype of a novel familial Möbius-like syndrome

    PubMed Central

    Dumars, Sean; Andrews, Caroline; Chan, Wai-Man; Engle, Elizabeth C.; Demer, Joseph L.

    2008-01-01

    Introduction Möbius’ syndrome typically presents as a sporadic trait with congenital facial palsy and abduction impairment. We used high resolution magnetic resonance imaging (MRI) and genetic analysis to examine a family with features of Möbius’ syndrome. Methods We examined three related family members having congenital complete opthalmoplegia with ptosis and facial diplegia. Orbits were imaged in quasi-coronal and sagittal planes 2 mm thick. Subarachnoid cranial nerves were imaged in planes 1 mm thick. Linkage and mutation analysis were performed to determine if the pedigree harbored mutations in four candidate genes. Results In affected subjects, MRI showed marked hypoplasia of extraocular muscles and intraorbital motor nerves. In the anterior orbit, rectus extraocular muscles were less hypoplastic but markedly curved toward insertion. Oblique extraocular muscles were hypoplastic and abnormally inserted. Posterior bony orbits were hypoplastic. Optic nerves were markedly straightened. Brainstems and cranial nerves III, VI, VII, and VIII were normal bilaterally. No pathogenic mutations were detected in affected individuals. Conclusions Previous MRI studies have demonstrated brainstem hypoplasia and cranial nerve aplasia in Möbius’ syndrome. The current family had normal brainstems and subarachnoid portions of motor cranial nerves innervating the orbit, but marked extraocular muscle hypoplasia. These clinical and MRI findings are atypical for Möbius’ syndrome and other congenital cranial dysinnervation disorders (CCDDs). Congenital facial weakness and complete ophthalmoplegia may occur despite MRI evidence of normal brainstem anatomy. The endophenotype appears to result from a genetic defect distinct from the CCDDs defined thus far, rather than a global brainstem insult. PMID:18455936

  18. AB024. The penile dermal flap* for defect reconstruction in Peyronie’s disease (PD) deformities

    PubMed Central

    Krishnamurti, Sudhakar

    2015-01-01

    Objective Generally speaking, historically, two main types of surgical treatments have been used to straighten penis deformity in Peyronie’s disease (PD)*: viz. (I) plication procedures; and (II) assorted graft materials to close defects in the tunica albuginea after plaque/deformity excision/release. Many different techniques have been described under each category. Curiously, flaps* (cf. free grafts), which are widely used in many other surgical applications, have hardly been tried in PD. The first description of a pedicled, epidermis-free, dermal penile skin flap for covering the tunica albuginea defect after plaque incision/excision in PD was made by this author in 1992 at the Milan ISSM meeting. In 1994, at the Singapore ISSM meeting, the penile dermal flap operation was awarded the ISSM’s prestigious biennial Herbert Newman award for best paper in original clinical research in the field of sexual health. In this talk, attention is drawn to the biological and cost advantages of having and using biological auto flaps, and it’s operative technique, advantages and long term results. S. KRISHNAMURTI: ‘Penile dermal flap for defect reconstruction in Peyronie’s disease: operative technique and four years’ experience in 17 patients.’ Int J Impotence Res (1995) 7, 195-208.’ In this presentation, the operative technique in both, circumcised and uncircumcised Peyronie’s disease patients will be shown with slides and videos. Methods Operative technique video and PPT slides to be shown. Results Presented in body of talk. Conclusions When available, simple, autologous local pedicled flap ideal material for PD defect closure.

  19. [A complex study of the movement biomechanics in patients with post-stroke hemiparesis].

    PubMed

    Skvortsov, D V; Bulatova, M A; Kovrazhkina, E A; Suvorov, A Iu; Ivanova, G E; Skvortsova, V I

    2012-01-01

    The authors present results of a pilot study on biomechanics of non-cyclic movements of the human consequent verticalization in the ontogenesis of patients with post-stroke hemiparesis (10 patients in the acute stage of cerebral stroke) and 10 healthy volunteers without neurologic and orthopedic pathology. Some movements of therapeutic exercises Balance (a model of ontogenetic kinesitherapy) have been selected for the study. Cinematic parameters have been recorded using a system of motion 3D video analysis, a kinematic model was build in accordance to standard protocols. The skin (native and straightened) electromyogram (EMG) was recorded synchronously with kinematic data using 16-channel electromyography from the following pairs of muscles: mm. sternocleido-mastoideus, trapezius (горизонтальная порция), biceps brachii, triceps brachii, rectus femoris, adductor magnus. Major differences in the EMG picture between patients and controls were: 1) the EMG "monotony" with the involvement of multiple additional muscles in locomotions with the prevalence of the peculiar "tonic" muscle activity (low amplitudes without distinct peaks), stretching along the whole cycle of movement. In controls, EMG demonstrated variability and had mostly "phasic" character with distinct 1 or 2 peaks; 2) the asymmetry of EMG profile in symmetric movements. i.e. when performed simultaneously from the right and from the left sides. The latter feature may be considered as predictive because it was never found in healthy people. It allows to identify objectively weak muscles even in the absence of visible parethis during the routine neurological examination. PMID:22983241

  20. Assessment of the roles of serines 5.43(239) and 5.46(242) for binding and potency of agonist ligands at the human serotonin 5-HT2A receptor.

    PubMed

    Braden, Michael R; Nichols, David E

    2007-11-01

    We assessed the relative importance of two serine residues located near the top of transmembrane helix 5 of the human 5-HT(2A) receptor, comparing the wild type with S5.43(239)A or S5.46(242)A mutations. Using the ergoline lysergic acid diethylamide (LSD), and a series of substituted tryptamine and phenethylamine 5-HT(2A) receptor agonists, we found that Ser5.43(239) is more critical for agonist binding and function than Ser5.46(242). Ser5.43(239) seems to engage oxygen substituents at either the 4- or 5-position of tryptamine ligands and the 5-position of phenylalkylamine ligands. Even when a direct binding interaction cannot occur, our data suggest that Ser5.43(239) is still important for receptor activation. Polar ring-substituted tryptamine ligands also seem to engage Ser5.46(242), but tryptamines lacking such a substituent may adopt an alternate binding orientation that does not engage this residue. Our results are consistent with the role of Ser5.43(239) as a hydrogen bond donor, whereas Ser5.46(242) seems to serve as a hydrogen bond acceptor. These results are consistent with the functional topography and utility of our in silico-activated homology model of the h5-HT(2A) receptor. In addition, being more distal from the absolutely conserved Pro5.50, a strong interaction with Ser5.43(239) may be more effective in straightening the kink in helix 5, a feature that is possibly common to all type A GPCRs that have polar residues at position 5.43. PMID:17715398

  1. Development of an axial flow ventricular assist device: in vitro and in vivo evaluation.

    PubMed

    Mizuguchi, K; Damm, G; Benkowsky, R; Aber, G; Bacak, J; Svjkovsky, P; Glueck, J; Takatani, S; Nosé, Y; Noon, G P

    1995-07-01

    A collaborative effort between Baylor College of Medicine and NASA/Johnson Space Center is underway to develop an axial flow ventricular assist device (VAD). We evaluated inducer/impeller component designs in a series of in vitro hemolysis tests. As a result of computational fluid dynamic analysis, a flow inducer was added to the front of the pump impeller. According to the surface pressure distribution, the flow inducer blades were connected to the impeller long blades. This modification eliminated high negative pressure areas at the leading edge of the impeller. Comparative studies were performed between inducer blade sections that flowed smoothly into the impeller blades (continuous blades) and those that formed discrete separate pumping sections (discontinuous blades). The inducer/impeller with continuous blades showed significantly (p < 0.003) lower hemolysis with a normalized index of hemolysis (NIH) of 0.018 +/- 0.007 g/100 L (n = 3), compared with the discontinuous model, which demonstrated an NIH of 0.050 +/- 0.007 g/100 L (n = 3). The continuous blade model was evaluated in vivo for 2 days with no problems. One of the pumps evaluated ran for 5 days in vivo although thrombus formation was recognized on the flow straightener and the inducer/impeller. As a result of this study, the pump material was changed from polyether polyurethane to polycarbonate. The fabrication method was also changed to a computer numerically controlled (CNC) milling process with a final vapor polish. These changes resulted in an NIH of 0.0029 +/- 0.0009 g/100 L (n = 4), which is a significant (p < .0001) value 6 times less than that of the previous model.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8572968

  2. Evaluation of the impeller shroud performance of an axial flow ventricular assist device using computational fluid dynamics.

    PubMed

    Su, Boyang; Chua, Leok P; Lim, Tau M; Zhou, Tongming

    2010-09-01

    Generally, there are two types of impeller design used in the axial flow blood pumps. For the first type, which can be found in most of the axial flow blood pumps, the magnet is embedded inside the impeller hub or blades. For the second type, the magnet is embedded inside the cylindrical impeller shroud, and this design has not only increased the rotating stability of the impeller but has also avoided the flow interaction between the impeller blade tip and the pump casing. Although the axial flow blood pumps with either impeller design have been studied individually, the comparisons between these two designs have not been conducted in the literature. Therefore, in this study, two axial flow blood pumps with and without impeller shrouds were numerically simulated with computational fluid dynamics and compared with each other in terms of hydraulic and hematologic performances. For the ease of comparison, these two models have the same inner components, which include a three-blade straightener, a two-blade impeller, and a three-blade diffuser. The simulation results showed that the model with impeller shroud had a lower static pressure head with a lower hydraulic efficiency than its counterpart. It was also found that the blood had a high possibility to deposit on the impeller shroud inner surface, which greatly enhanced the possibility of thrombus formation. The blood damage indices in both models were around 1%, which was much lower than the 13.1% of the axial flow blood pump of Yano et al. with the corresponding experimental hemolysis of 0.033 g/100 L. PMID:20883393

  3. Numerical investigation of the effects of the clearance gap between the inducer and impeller of an axial blood pump.

    PubMed

    Chan, Weng-Kong; Wong, Yew-Wah; Ong, Wendy; Koh, Sy-Yuan; Chong, Victor

    2005-03-01

    A series of numerical models are generated to investigate the flow characteristics and performance of an axial blood pump. The pump model includes a straightener, an inducer-impeller, and diffuser. Numerical studies of the effects of angular alignment of the inducer and impeller blades and the axial clearance gap between the inducer and impeller are presented in this article. The pump characteristics derived from numerical simulation are validated with experimental data. Numerically simulated results showed a sinusoidal variation in the pressure generated across the pump with changes in angular alignment between the inducer and impeller. This is attributed to additional losses when flow is forced or diverted from the trailing edge of the inducer to either the pressure or suction side of the impeller blade when the alignment between the two sets of blades is not optimal. The pressure generated is a maximum when the impeller blades are at 0 or 30 degrees with respect to the inducer. The effect of rotating the impeller with respect to the inducer causes the sinusoidal pressure variation. In addition, it was observed that when the clearance gap between the inducer and impeller is reduced to 1 mm, the pressure generated is a minimum when compared to the other models. This is attributed to the interference between the inducer and impeller when the gap separating them is too small. The location of the maximum pressure on the pressure side of the impeller blade shifts upstream while its magnitude decreases for small clearance gap between the inducer and the impeller. There was no flow separation in the inducer while small regions of backflow are observed at the impeller trailing edge. Recommendations for future modifications and improvements to the pump design and model simulation are also given. PMID:15725228

  4. Preliminary Results of the Effect of Spinal Elongation in Microgravity on Seated Height

    NASA Technical Reports Server (NTRS)

    Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

    2009-01-01

    The Constellation Program is designing a new vehicle for future space travel to the International Space Station and to the Moon and beyond. One major accommodation and design issue that needs to be addressed with the current seat layout design is spinal elongation. Spinal elongation is the spinal growth that occurs due to straightening of the spinal curve and expansion of the inter-verbal discs in microgravity. Spinal elongation is critical to the design of the seats, seat layout, suit fit, and crew accommodation because of the implications it can have on the a safe return of the crewmembers or during the mission. Inadequate clearance between crewmembers and/or between crewmember hardware interfaces may potentially result in injury during the mission or upon returning to earth. Therefore, design requirements need to be determined that will allow for the elongation of the spine. The current requirement as specified in the Human Systems Integration Requirement (HSIR) document states that a 3% increase in standing height must be accommodated. However, it cannot be assumed that the amount of standing height growth is equivalent to the amount of spinal elongation because of the variation in body proportions between the lower body and torso. Thus, the purpose of this study was to determine the amount of spinal elongation for a seated posture for 6 Shuttle and 7 ISS missions. Crewmembers seated heights were collected before, during, and after spaceflight to determine the change in seated height and the amount of spinal growth that occurs due to microgravity. The changes in seated height will provide the designers with a design requirement that will allow for change in spinal growth for a seated posture. Preliminary results have shown that increase in seated height is greater than the 3% increase currently stated in the requirement.

  5. Sticking under wet conditions: the remarkable attachment abilities of the torrent frog, Staurois guttatus.

    PubMed

    Endlein, Thomas; Barnes, W Jon P; Samuel, Diana S; Crawford, Niall A; Biaw, Ang Bee; Grafe, Ulmar

    2013-01-01

    Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad. PMID:24086297

  6. Use of hot formaldehyde fixative in processing plant-parasitic nematodes for electron microscopy.

    PubMed

    Zeikus, J A; Aldrich, H C

    1975-07-01

    A preparative technique is formulated for processing plant-parasitic nematodes of the order Tylenchida for electron microscopy. A population of Dolichodorus heterocephalus is used as test objects. One and a half grams of paraformaldehyde are dissolved in 25 ml of water at 60 C. Five drops of 1 N sodium hydroxide are added to clear the solution, which is then cooled to room temperature. Two and a half milliliters of 25% glutaraldehyde are added with 23 ml 0.1 M phosphate buffer, pH 7.3, and 0.2 M with respect to sucrose. The final solution contains 3% formaldehyde and 1% glutaraldehyde and is pH 7.2. It is heated to 70 C, poured over specimens, and allowed to cool to 4 C in 2 hr. The nematodes are then incised in a fixative containing 2% glutaraldehyde and 5% dimethyl sulfoxide at 4 C for 16-24 hr. Five milliliters of 25% glutaraldehyde and 2.5 ml of dimethyl sulfoxide are combined in 17.5 ml of water. Twenty-five milliliters of phosphate buffer (supplemented as above) are added. The final pH is 7.2. The glutaraldehyde, aided by dimethyl sulfoxide, uniformly and permanently fixes the nematode tissues. The specimens are embedded in agar. Following a 30-min buffer wash (4 C) they are postfixed in buffered 2% osmium tetroxide for 2 hr at room temperature, washed, and dehydrated through an ethanol series and two acetone baths. Dehydration includes a 2-hr stop in 75% ethanol containing 2% uranyl acetate. After embedding in Spurr's epoxy resin, specimens are sectioned and poststained in 0.5% aqueous acetate for 6 min and saturated aqueous lead citrate 3--4 min. This technique reduces killing time to less than 2 sec, straightens specimens for easier orientation, and eliminates the typically high internal pressure of nematodes which causes displacement of internal structures observed with other fixation techniques. PMID:1103371

  7. Froude Number is the Single Most Important Hydraulic Parameter for Salmonid Spawning Habitat.

    NASA Astrophysics Data System (ADS)

    Gillies, E.; Moir, H. J.

    2015-12-01

    Many gravel-bed rivers exhibit historic straightening or embanking, reducing river complexity and the available habitat for key species such as salmon. A defensible method for predicting salmonid spawning habitat is an important tool for anyone engaged in assessing a river restoration. Most empirical methods to predict spawning habitat use lookup tables of depth, velocity and substrate. However, natural site selection is different: salmon must pick a location where they can successfully build a redd, and where eggs have a sufficient survival rate. Also, using dimensional variables, such as depth and velocity, is problematic: spawning occurs in rivers of differing size, depth and velocity range. Non-dimensional variables have proven useful in other branches of fluid dynamics, and instream habitat is no different. Empirical river data has a high correlation between observed salmon redds and Froude number, without insight into why. Here we present a physics based model of spawning and bedform evolution, which shows that Froude number is indeed a rational choice for characterizing the bedform, substrate, and flow necessary for spawning. It is familiar for Froude to characterize surface waves, but Froude also characterizes longitudinal bedform in a mobile bed river. We postulate that these bedforms and their hydraulics perform two roles in salmonid spawning: allowing transport of clasts during redd building, and oxygenating eggs. We present an example of this Froude number and substrate based habitat characterization on a Scottish river for which we have detailed topography at several stages during river restoration and subsequent evolution of natural processes. We show changes to the channel Froude regime as a result of natural process and validate habitat predictions against redds observed during 2014 and 2015 spawning seasons, also relating this data to the Froude regime in other, nearby, rivers. We discuss the use of the Froude spectrum in providing an indicator of

  8. Early-life glucocorticoids programme behaviour and metabolism in adulthood in zebrafish.

    PubMed

    Wilson, K S; Tucker, C S; Al-Dujaili, E A S; Holmes, M C; Hadoke, P W F; Kenyon, C J; Denvir, M A

    2016-07-01

    Glucocorticoids (GCs) in utero influence embryonic development with consequent programmed effects on adult physiology and pathophysiology and altered susceptibility to cardiovascular disease. However, in viviparous species, studies of these processes are compromised by secondary maternal influences. The zebrafish, being fertilised externally, avoids this problem and has been used here to investigate the effects of transient alterations in GC activity during early development. Embryonic fish were treated either with dexamethasone (a synthetic GC), an antisense GC receptor (GR) morpholino (GR Mo), or hypoxia for the first 120h post fertilisation (hpf); responses were measured during embryonic treatment or later, post treatment, in adults. All treatments reduced cortisol levels in embryonic fish to similar levels. However, morpholino- and hypoxia-treated embryos showed delayed physical development (slower hatching and straightening of head-trunk angle, shorter body length), less locomotor activity, reduced tactile responses and anxiogenic activity. In contrast, dexamethasone-treated embryos showed advanced development and thigmotaxis but no change in locomotor activity or tactile responses. Gene expression changes were consistent with increased (dexamethasone) and decreased (hypoxia, GR Mo) GC activity. In adults, stressed cortisol values were increased with dexamethasone and decreased by GR Mo and hypoxia pre-treatments. Other responses were similarly differentially affected. In three separate tests of behaviour, dexamethasone-programmed fish appeared 'bolder' than matched controls, whereas Mo and hypoxia pre-treated fish were unaffected or more reserved. Similarly, the dexamethasone group but not the Mo or hypoxia groups were heavier, longer and had a greater girth than controls. Hyperglycaemia and expression of GC responsive gene (pepck) were also increased in the dexamethasone group. We conclude that GC activity controls many aspects of early-life growth and

  9. Arabidopsis myosin XI: a motor rules the tracks.

    PubMed

    Cai, Chao; Henty-Ridilla, Jessica L; Szymanski, Daniel B; Staiger, Christopher J

    2014-11-01

    Plant cell expansion relies on intracellular trafficking of vesicles and macromolecules, which requires myosin motors and a dynamic actin network. Arabidopsis (Arabidopsis thaliana) myosin XI powers the motility of diverse cellular organelles, including endoplasmic reticulum, Golgi, endomembrane vesicles, peroxisomes, and mitochondria. Several recent studies show that there are changes in actin organization and dynamics in myosin xi mutants, indicating that motors influence the molecular tracks they use for transport. However, the mechanism by which actin organization and dynamics are regulated by myosin XI awaits further detailed investigation. Here, using high spatiotemporal imaging of living cells, we quantitatively assessed the architecture and dynamic behavior of cortical actin arrays in a mutant with three Myosin XI (XI-1, XI-2, and XI-K) genes knocked out (xi3KO). In addition to apparent reduction of organ and cell size, the mutant showed less dense and more bundled actin filament arrays in epidermal cells. Furthermore, the overall actin dynamicity was significantly inhibited in the xi3KO mutant. Because cytoskeletal remodeling is contributed mainly by filament assembly/disassembly and translocation/buckling, we also examined the dynamic behavior of individual actin filaments. We found that the xi3KO mutant had significantly decreased actin turnover, with a 2-fold reduction in filament severing frequency. Moreover, quantitative analysis of filament shape change over time revealed that myosin XI generates the force for buckling and straightening of both single actin filaments and actin bundles. Thus, our data provide genetic evidence that three Arabidopsis class XI myosins contribute to actin remodeling by stimulating turnover and generating the force for filament shape change. PMID:25237128

  10. Historical Channel Change on the Upper Gila River, Arizona and New Mexico in Response to Anthropogenic Modifications and Extreme Floods

    NASA Astrophysics Data System (ADS)

    Klawon, J. E.; Levish, D. R.

    2003-12-01

    opposite banks, breaching of levees during floods and resultant erosion behind levees, channel widening downstream of levees, aggradation in leveed reaches, and lateral migration associated with straightened tributary channels.

  11. Distal bimelic amyotrophy (DBMA): Phenotypically distinct but identical on cervical spine MR imaging with brachial monomelic amyotrophy/Hirayama disease.

    PubMed

    Preethish-Kumar, Veeramani; Nalini, Atchayaram; Singh, Ravinder-Jeet; Saini, Jitender; Prasad, Chandrajit; Polavarapu, Kiran; Thennarasu, Kandavel

    2015-01-01

    Our objective was to characterize the MR imaging features in a large and distinct series of distal bimelic amyotrophy (DBMA) from India. We utilized a retrospective and prospective study on 26 cases. Results demonstrated that upper limb distal muscle wasting and weakness was predominantly symmetrical in onset. Mean age at onset was 20.9 ± 7.0 years, mean duration 83.0 ± 102.6 months. MRI carried out in 22 patients with flexion studies showed forward displacement of posterior dura in 19 (86.4%). Crescent shaped epidural enhancement on contrast was seen in 20/24 cases (83.3%), and bilateral T2W hyperintensities of cord in17 (65.4%) - symmetrical in15 cases. Maximum hyperintensity was noted at C5-C6, C6-C7 levels. Cord atrophy was noted in 24 (92.3%) cases (most affected: C5-C6, C6-C7) - symmetrical atrophy in 21cases. Cervical spine straightening occurred in six (23.1%) cases and reversal of lordosis in 15 (57.7%). In conclusion, this study confirms that DBMA is phenotypically distinct but pathophysiologically the same as brachial monomelic amyotrophy (BMMA) on MR imaging. Typical MRI features were seen in all. It is important to differentiate this disorder from ALS, which could present at a younger age as often seen among Indians. The clinical and MR imaging features are highly suggestive that DBMA, as with BMMA/Hirayama disease, occurs due to dynamic alterations at the cervical spine level. PMID:25967543

  12. The comparative analysis of rocks' resistance to forward-slanting disc cutters and traditionally installed disc cutters

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao-Huang; Fei, Sun; Liang, Meng

    2015-12-01

    At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the operation life of disc cutters, but also increases the energy consumption of a full face rock tunnel boring machine. To straighten out this issue, therefore, a rock-breaking model is developed for disc cutters' movement after the research on the rock breaking of forward-slanting disc cutters. Equations of its displacement are established based on the analysis of velocity vector of a disc cutter's rock-breaking point. The functional relations then are brought forward between the displacement parameters of a rock-breaking point and its coordinate through the analysis of micro displacement of a rock-breaking point. Thus, the geometric equations of rock deformation are derived for the forward-slanting installation of disc cutters. With a linear relationship remaining between the acting force and its deformation either before or after the leap breaking, the constitutive relation of rock deformation can be expressed in the form of generalized Hooke law, hence the comparative analysis of the variation in the resistance of rock to the disc cutters mounted in the forward-slanting way with that in the traditional way. It is discovered that with the same penetration, strain of the rock in contact with forward-slanting disc cutters is apparently on the decline, in other words, the resistance of rock to disc cutters is reduced. Thus wear of disc cutters resulted from friction is lowered and energy consumption is correspondingly decreased. It will be useful for the development of installation and design theory of disc cutters, and significant for the breakthrough in the design of full face rock tunnel boring machine.

  13. Panostotic Expansile Bone Disease With Massive Jaw Tumor Formation and a Novel Mutation in the Signal Peptide of RANK

    PubMed Central

    Schafer, Anne L; Mumm, Steven; El-Sayed, Ivan; McAlister, William H; Horvai, Andrew E; Tom, Andrea M; Hsiao, Edward C; Schaefer, Frederick V; Collins, Michael T; Anderson, Mark S; Whyte, Michael P; Shoback, Dolores M

    2015-01-01

    Precise regulation of bone resorption is critical for skeletal homeostasis. We report a 32-year-old man with a panostotic expansile bone disease and a massive hemorrhagic mandibular tumor. Originally from Mexico, he was deaf at birth and became bow-legged during childhood. There was no family history of skeletal disease. Puberty occurred normally, but during adolescence he experienced difficulty straightening his limbs, sustained multiple fractures, and developed a bony tumor on his chin. By age 18 years, all limbs were misshapen. The mandibular mass grew and protruded from the oral cavity, extending to the level of the lower ribs. Other bony defects included a similar maxillary mass and serpentine limbs. Upon referral at age 27 years, biochemical studies showed serum alkaline phosphatase of 1760 U/L (Nl: 29-111) and other elevated bone turnover markers. Radiography of the limbs showed medullary expansion and cortical thinning with severe bowing. Although the jaw tumors were initially deemed inoperable, mandibular mass excision and staged partial maxillectomy were eventually performed. Tumor histopathology showed curvilinear trabeculae of woven bone on a background of hypocellular fibrous tissue. Fibrous dysplasia of bone was suspected, but there was no mutation in codon 201 of GNAS in samples from blood or tumor. His clinical and radiographic findings, elevated serum markers, and disorganized bone morphology suggested amplified receptor activator of NF-κB (RANK) signaling, even though his disorder differed from conditions with known constitutive activation of RANK signaling (eg, familial expansile osteolysis). We found a unique 12-base pair duplication in the signal peptide of TNFRSF11A, the gene that encodes RANK. No exon or splice site mutations were found in the genes encoding RANK ligand or osteoprotegerin. Alendronate followed by pamidronate therapies substantially decreased his serum alkaline phosphatase activity. This unique patient expands the phenotypes

  14. Hydrology, geomorphology, and flood profiles of Lemon Creek, Juneau, Alaska

    USGS Publications Warehouse

    Host, Randy H.; Neal, Edward G.

    2005-01-01

    Lemon Creek near Juneau, Alaska has a history of extensive gravel mining, which straightened and deepened the stream channel in the lower reaches of the study area. Gravel mining and channel excavation began in the 1940s and continued through the mid-1980s. Time sequential aerial photos and field investigations indicate that the channel morphology is reverting to pre-disturbance conditions through aggradation of sediment and re-establishment of braided channels, which may result in decreased channel conveyance and increased flooding potential. Time sequential surveys of selected channel cross sections were conducted in an attempt to determine rates of channel aggradation/degradation throughout three reaches of the study area. In order to assess flooding potential in the lower reaches of the study area the U.S. Army Corps of Engineers Hydrologic Engineering Center River Analysis System model was used to estimate the water-surface elevations for the 2-, 10-, 25-, 50-, and 100-year floods. A regionally based regression equation was used to estimate the magnitude of floods for the selected recurrence intervals. Forty-two cross sections were surveyed to define the hydraulic characteristics along a 1.7-mile reach of the stream. High-water marks from a peak flow of 1,820 cubic feet per second, or about a 5-year flood, were surveyed and used to calibrate the model throughout the study area. The stream channel at a bridge in the lower reach could not be simulated without violating assumptions of the model. A model without the lower bridge indicates flood potential is limited to a small area.

  15. On the effects of leaflet microstructure and constitutive model on the closing behavior of the mitral valve.

    PubMed

    Lee, Chung-Hao; Rabbah, Jean-Pierre; Yoganathan, Ajit P; Gorman, Robert C; Gorman, Joseph H; Sacks, Michael S

    2015-11-01

    Recent long-term studies showed an unsatisfactory recurrence rate of severe mitral regurgitation 3-5 years after surgical repair, suggesting that excessive tissue stresses and the resulting strain-induced tissue failure are potential etiological factors controlling the success of surgical repair for treating mitral valve (MV) diseases. We hypothesized that restoring normal MV tissue stresses in MV repair techniques would ultimately lead to improved repair durability through the restoration of MV normal homeostatic state. Therefore, we developed a micro- and macro- anatomically accurate MV finite element model by incorporating actual fiber microstructural architecture and a realistic structure-based constitutive model. We investigated MV closing behaviors, with extensive in vitro data used for validating the proposed model. Comparative and parametric studies were conducted to identify essential model fidelity and information for achieving desirable accuracy. More importantly, for the first time, the interrelationship between the local fiber ensemble behavior and the organ-level MV closing behavior was investigated using a computational simulation. These novel results indicated not only the appropriate parameter ranges, but also the importance of the microstructural tuning (i.e., straightening and re-orientation) of the collagen/elastin fiber networks at the macroscopic tissue level for facilitating the proper coaptation and natural functioning of the MV apparatus under physiological loading at the organ level. The proposed computational model would serve as a logical first step toward our long-term modeling goal-facilitating simulation-guided design of optimal surgical repair strategies for treating diseased MVs with significantly enhanced durability. PMID:25947879

  16. Late glacial river-bed changes on the Little Hungarian Plain based on preliminary chronological, geological and paleontological data

    NASA Astrophysics Data System (ADS)

    Sávai, Szilvia; Molnár, Dávid; Sümegi, Pál

    2015-10-01

    Comprehensive chronological, geological and paleontological investigations were conducted as part of archaeological excavations in 2011 and 2012, prior to the construction of the M85 motorway between Gyor and Csorna, Hungary. These studies clearly show that the alluvial fan that underlies much of the Little Hungarian Plain was built up by streams flowing in a southeasterly to northwesterly direction from the nearby Bakony Hills, and continued to form until the end of the last glacial period. The northern part of the fan, now named the Csorna Plain, became inactive (i.e. became a fossil river-bed system) at about 25-15 ka, when the Rába and Marcal rivers changed theirflowdirection fromsouth-north towest-east.As a result of this change in flow direction, the Rába and Marcal rivers became incised, capturing the Bakony stream beds, stopping sediment deposition on the northern side of the alluvial fan (essentially the left bank of the Rába-Marcal river system), although the southern part of the fan continue to form as before. On the northern side of the fan, the sediment surface dried out due to falling groundwater levels, and aeolian sand-drifts began to form. Eventually, accumulation of the sand-drift sediments ceased due to the deposition of loess-type sediments, which fixed the surface, conserved the sand-drift shapes, and contributed to the straightening and eventual canalization of the fluvial channels. Geoarchaeological examinations indicate that the development of present fluvial features were strongly affected by the settlement and tillage activity of human communities on the Csorna Plain.

  17. Lower Red River Meadow Restoration Project : Biennial Report 1996-97.

    SciTech Connect

    LRK Communications; Wildlife Habitat Institute; Pocket Water, Inc.

    2003-07-01

    The Red River has been straightened and the riparian vegetation corridor eliminated in several reaches within the watershed. The river responded by incision resulting in over-steepened banks, increased sedimentation, elevated water temperatures, depressed groundwater levels, reduced floodplain function, and degraded fish habitat. The Lower Red River Meadow Restoration Project is a multi-phase ecosystem enhancement effort that restores natural physical and biological processes and functions to stabilize the stream channel and establish high quality habitats for fish and wildlife. A natural channel restoration philosophy guides the design and on the ground activities, allowing the channel to evolve into a state of dynamic equilibrium. Two years of planning, two years of restoration in Phases I and II, and one year post-restoration monitoring are complete. By excavating new bends and reconnecting historic meanders, Phase I and II channel realignment increased channel length by 3,060 feet, decreased channel gradient by 25 percent, and increased sinuosity from 1.7 to 2.3. Cross-sectional shapes and point bars were modified to maintain deep pool habitat at low flow and to reconnect the meadow floodplain. Improved soil moisture conditions will help sustain the 31,500 native riparian plantings reestablished within these two phases. Overall, short-term restoration performance was successful. Analyses of long-term parameters document either post-restoration baseline conditions or early stages of evolution toward desired conditions. An adaptive management strategy has helped to improve restoration designs, methods, and monitoring. Lessons learned are being transferred to a variety of audiences to advance the knowledge of ecological restoration and wise management of watersheds.

  18. Multivariable Dynamic Ankle Mechanical Impedance With Relaxed Muscles

    PubMed Central

    Lee, Hyunglae; Krebs, Hermano Igo; Hogan, Neville

    2015-01-01

    Neurological or biomechanical disorders may distort ankle mechanical impedance and thereby impair locomotor function. This paper presents a quantitative characterization of multivariable ankle mechanical impedance of young healthy subjects when their muscles were relaxed, to serve as a baseline to compare with pathophysiological ankle properties of biomechanically and/or neurologically impaired patients. Measurements using a highly backdrivable wearable ankle robot combined with multi-input multi-output stochastic system identification methods enabled reliable characterization of ankle mechanical impedance in two degrees-of-freedom (DOFs) simultaneously, the sagittal and frontal planes. The characterization included important ankle properties unavailable from single DOF studies: coupling between DOFs and anisotropy as a function of frequency. Ankle impedance in joint coordinates showed responses largely consistent with a second-order system consisting of inertia, viscosity, and stiffness in both seated (knee flexed) and standing (knee straightened) postures. Stiffness in the sagittal plane was greater than in the frontal plane and furthermore, was greater when standing than when seated, most likely due to the stretch of bi-articular muscles (medial and lateral gastrocnemius). Very low off-diagonal partial coherences implied negligible coupling between dorsiflexion-plantarflexion and inversion-eversion. The directions of principal axes were tilted slightly counterclockwise from the original joint coordinates. The directional variation (anisotropy) of ankle impedance in the 2-D space formed by rotations in the sagittal and frontal planes exhibited a characteristic “peanut” shape, weak in inversion-eversion over a wide range of frequencies from the stiffness dominated region up to the inertia dominated region. Implications for the assessment of neurological and biomechanical impairments are discussed. PMID:24686292

  19. VizieR Online Data Catalog: Library of ELODIE spectra (F5-K7 stars) (Soubiran+ 1998)

    NASA Astrophysics Data System (ADS)

    Soubiran, C.; Katz, D.; Cayrel, R.

    1998-06-01

    A library of 211 echelle spectra taken with ELODIE at the Observatoire de Haute-Provence is proposed. It provides a set of spectroscopic standards covering the full range of gravities and metallicities in the effective temperature interval [4000K, 6300K]. The spectra are straightened, wavelength calibrated, cleaned of cosmic ray hits, bad pixels and telluric lines. They cover the spectral range [440nm, 680nm] with an instrumental resolution of 42000. For each star, basic data were compiled from the Hipparcos catalogue (Cat. ) and the Hipparcos Input Catalogue (Cat. ) (Table 1). Radial velocities with a precision better than 100m/s are given. Atmospheric parameters Teff, logg, [Fe/H] from the literature are discussed. Because of scattered determinations in the bibliography, even for the most well-known stars, these parameters were adjusted by an iterative process which takes account of common or different spectral features between the standards, using our homogeneous set of spectra. Revised values of effective temperature, gravity and metallicity are proposed in Table 1. They are still consistent with the literature, and also lead to the self-consistency of the library, in the sense that similar spectra have similar atmospheric parameters. This adjustment was performed by using step by step a method based on the least square comparison of carefully prepared spectra, which was originally developed for the on-line estimation of the atmospheric parameters of faint field stars (Katz et al., 1998A&A...338..151K. Paper I.). (3 data files).

  20. 3D Topography of the Young Adult Anal Sphincter Complex Reconstructed from Undeformed Serial Anatomical Sections

    PubMed Central

    Wu, Yi; Dabhoiwala, Noshir F.; Hagoort, Jaco; Shan, Jin-Lu; Tan, Li-Wen; Fang, Bin-Ji; Zhang, Shao-Xiang; Lamers, Wouter H.

    2015-01-01

    Background Pelvic-floor anatomy is usually studied by artifact-prone dissection or imaging, which requires prior anatomical knowledge. We used the serial-section approach to settle contentious issues and an interactive 3D-pdf to make the results widely accessible. Method 3D reconstructions of undeformed thin serial anatomical sections of 4 females and 2 males (21–35y) of the Chinese Visible Human database. Findings Based on tendinous septa and muscle-fiber orientation as segmentation guides, the anal-sphincter complex (ASC) comprised the subcutaneous external anal sphincter (EAS) and the U-shaped puborectal muscle, a part of the levator ani muscle (LAM). The anococcygeal ligament fixed the EAS to the coccygeal bone. The puborectal-muscle loops, which define the levator hiatus, passed around the anorectal junction and inserted anteriorly on the perineal body and pubic bone. The LAM had a common anterior attachment to the pubic bone, but separated posteriorly into puborectal and “pubovisceral” muscles. This pubovisceral muscle was bilayered: its internal layer attached to the conjoint longitudinal muscle of the rectum and the rectococcygeal fascia, while its outer, patchy layer reinforced the inner layer. ASC contraction makes the ano-rectal bend more acute and lifts the pelvic floor. Extensions of the rectal longitudinal smooth muscle to the coccygeal bone (rectococcygeal muscle), perineal body (rectoperineal muscle), and endopelvic fascia (conjoint longitudinal and pubovisceral muscles) formed a “diaphragm” at the inferior boundary of the mesorectum that suspended the anorectal junction. Its contraction should straighten the anorectal bend. Conclusion The serial-section approach settled contentious topographic issues of the pelvic floor. We propose that the ASC is involved in continence and the rectal diaphragm in defecation. PMID:26305117