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Sample records for armored rna internal

  1. A novel duplex real time quantitative reverse transcription polymerase chain reaction for rubella virus with armored RNA as a noncompetitive internal positive control.

    PubMed

    Zhao, Lihong; Li, Ruiying; Liu, Aihua; Zhao, Shuping

    2015-07-01

    The objective of this study was to build and apply a duplex real time quantitative reverse transcription-polymerase chain reaction (RT-PCR) for rubella virus. Firstly, a 60-bp-long armored RV RNA was constructed in the laboratory. Secondly, a duplex real time RT-PCR assay was established. Thirdly, the 60-bp-long armored RV RNA was used as an internal positive control (IPC) for the duplex real time RT-PCR. And finally the duplex real time RT-PCR assay was applied to detect RV RNA in clinical specimens. The in-house assay has a high amplification efficiency (0.99), a high analytical sensitivity (200 copies/mL), and a good reproducibility. The diagnostic specificity and sensitivity of the in-house assay were both 100%, due to the monitoring of the armored RV RNA IPC. Therefore, the in-house duplex real time quantitative RT-PCR assay is a specific, sensitive, reproducible and accurate assay for quantitation of RV RNA in clinical specimens. And noncompetitive armored RV RNA IPC can monitor RT-PCR inhibition and prevent false-negative and inaccurate results in the real time detection system.

  2. Spaced Armor

    DTIC Science & Technology

    1950-11-20

    less resistance to the penetration of a projectile than does the midsection of the plate. This is so because the front and rear surfaces of the armor ...Front -7idsectio " Aberdeen Proving Ground Report .AD-943, "Ballistic Test of Spaced Armor Arrangements which can be used for Increasing the Protection of... Ground . The target was to be a 100 • thick cast armor plate which can be quite easily penetrated by this carbide cored projectile at O0 obliquity

  3. Armored spring-core superconducting cable and method of construction

    DOEpatents

    McIntyre, Peter M.; Soika, Rainer H.

    2002-01-01

    An armored spring-core superconducting cable (12) is provided. The armored spring-core superconducting cable (12) may include a spring-core (20), at least one superconducting strand (24) wound onto the spring-core (20), and an armored shell (22) that encases the superconducting strands (24). The spring-core (20) is generally a perforated tube that allows purge gases and cryogenic liquids to be circulated through the armored superconducting cable (12), as well as managing the internal stresses within the armored spring-core superconducting cable (12). The armored shell (22) manages the external stresses of the armored spring-core superconducting cable (12) to protect the fragile superconducting strands (24). The armored spring-core superconducting cable (12) may also include a conductive jacket (34) formed outwardly of the armored shell (22).

  4. External quality assessment for enterovirus 71 and coxsackievirus A16 detection by reverse transcription-PCR using armored RNA as a virus surrogate.

    PubMed

    Song, Liqiong; Sun, Shipeng; Li, Bo; Pan, Yang; Li, Wenli; Zhang, Kuo; Li, Jinming

    2011-10-01

    Three armored RNAs (virus-like particles [VLPs]) containing target sequences from enterovirus 71 (EV71) and coxsackievirus A16 (CA16) and a pan-enterovirus (pan-EV) sequence were constructed and used in an external quality assessment (EQA) to determine the performance of laboratories in the detection of EV71 and CA16. The EQA panel, which consisted of 20 samples, including 14 positive samples with different concentrations of EV and either EV71 or CA16 armored RNAs, 2 samples with all 3 armored RNAs, and 4 negative-control samples (NaN(3)-preserved minimal essential medium [MEM] without VLPs), was distributed to 54 laboratories that perform molecular diagnosis of hand, foot, and mouth disease (HFMD) virus infections. A total of 41 data sets from 41 participants were returned; 5 (12.2%) were generated using conventional in-house reverse transcription-PCR (RT-PCR) assays, and 36 (87.8%) were generated using commercial real-time RT-PCR assays. Performance assessments of laboratories differed; 12 (29.3%) showed a need for improvement. Surprisingly, 4 laboratories were unable to detect EV71 RNA in any samples, even those containing the highest concentration of 10(7) IU/ml. Furthermore, the detection sensitivity for EV71 among all laboratories (82.1%) was substantially lower than that for EV (97.4%) or CA16 (95.1%). Overall, the results of the present study indicate that EQA should be performed periodically to help laboratories monitor their ability to detect HFMD viruses and to improve the comparability of results from different laboratories.

  5. Composite armor, armor system and vehicle including armor system

    DOEpatents

    Chu, Henry S.; Jones, Warren F.; Lacy, Jeffrey M.; Thinnes, Gary L.

    2013-01-01

    Composite armor panels are disclosed. Each panel comprises a plurality of functional layers comprising at least an outermost layer, an intermediate layer and a base layer. An armor system incorporating armor panels is also disclosed. Armor panels are mounted on carriages movably secured to adjacent rails of a rail system. Each panel may be moved on its associated rail and into partially overlapping relationship with another panel on an adjacent rail for protection against incoming ordnance from various directions. The rail system may be configured as at least a part of a ring, and be disposed about a hatch on a vehicle. Vehicles including an armor system are also disclosed.

  6. Armor structures

    DOEpatents

    Chu, Henry Shiu-Hung [Idaho Falls, ID; Lacy, Jeffrey M [Idaho Falls, ID

    2008-04-01

    An armor structure includes first and second layers individually containing a plurality of i-beams. Individual i-beams have a pair of longitudinal flanges interconnected by a longitudinal crosspiece and defining opposing longitudinal channels between the pair of flanges. The i-beams within individual of the first and second layers run parallel. The laterally outermost faces of the flanges of adjacent i-beams face one another. One of the longitudinal channels in each of the first and second layers faces one of the longitudinal channels in the other of the first and second layers. The channels of the first layer run parallel with the channels of the second layer. The flanges of the first and second layers overlap with the crosspieces of the other of the first and second layers, and portions of said flanges are received within the facing channels of the i-beams of the other of the first and second layers.

  7. Joining Steel Armor - Intermix

    DTIC Science & Technology

    1979-03-01

    TARADCOM a d ki Lk A el B~ 0el RWET0 TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX March 1979 U U * S* ’ "U .by B. . A.SCEV * U...authorized documents. O "if TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX BY B. A. SCHEVO March 1979 AMS: 3197..6D.4329 TARADCOM ARMOR AND...Intermix Process ...... ........ 3 Test Procedures - Intermix Armor ........ ......... 4 Mock Hull ................. ..................... 5 Results

  8. Shock destruction armor system

    DOEpatents

    Froeschner, Kenneth E.

    1993-01-01

    A shock destruction armor system is constructed and arranged to destroy the force of impact of a projectile by shock hydrodynamics. The armor system is designed to comprise a plurality of superimposed armor plates each preferably having a thickness less than five times the projectile's diameter and are preferably separated one-from-another by a distance at least equal to one-half of the projectile's diameter. The armor plates are effective to hydrodynamically and sequentially destroy the projectile. The armor system is particularly adapted for use on various military vehicles, such as tanks, aircraft and ships.

  9. Imaging body armor.

    PubMed

    Harcke, H Theodore; Schauer, David A; Harris, Robert M; Campman, Steven C; Lonergan, Gael J

    2002-04-01

    This study examined the feasibility of performing radiographic studies on patients wearing standard-issue body armor. The Kevlar helmet, fragmentation vest, demining suit sleeve, and armor plate were studied with plain film and computed tomography in a simulated casualty situation. We found that the military helmet contains metal screws and metal clips in the headband, but diagnostic computed tomographic images can be obtained. Kevlar, the principal component of soft armor, has favorable photon attenuation characteristics. Plate armor of composite material also did not limit radiographic studies. Therefore, when medically advantageous, patients can be examined radiographically while wearing standard military body armor. Civilian emergency rooms should be aware of these observations because law enforcement officers wear similar protective armor.

  10. M113: Armored Rescuer

    NASA Video Gallery

    The space shuttle required a unique rescue vehicle, one strong enough to bull its way into a launch pad and carry a flight crew and firefighters to safety. The answer is a group of M113 armored per...

  11. Field Expedient Armor Modifications to US Armored Vehicles

    DTIC Science & Technology

    2006-06-01

    field expedient modifications to armored vehicles. Second, the armored systems employed by US forces during operations Desert Shield -Desert Storm...fire. Crews quickly realized that the spare track, when mounted in critical locations, provided some measure against enemy kinetic armor piercing...Army Field Forces, 7 April 1952): Appendix G, p. 5. 5William P. Withers, “Report From Korea,” Armor 60, no. 2 (1951): 23. 59 6Harry H. Shields Jr

  12. Ballistic Testing of Armor Weldments

    DTIC Science & Technology

    1983-11-02

    and properties of armor plate b. Electrode used in weld c. Measured thickness of welded area and plate d. Temperature of plate during firing e...of different thicknesses. Armored vehicle structures of simu- lated sections of armored vehicles are tested for resistance to shock as described...following: a. Ambient temperature at time of testing b. For each round: (1) Type, thickness, and properties of armor (2) Measured location of impact

  13. Fragment Penetration Tests of Armor

    DTIC Science & Technology

    1983-03-15

    Identify by block numbhr) Provides techniques for evaluating armor resistance to attack by HE projectile fragments. Includes static detonations of shell...DISTRIBUTION D. REFERENCES * . . . ........ . ........... D-1 1. SCOPE. This TOP describes the available techniques for testing armor for resistance to attack by...Projectiles Against Armor Plates ("Yankee Stadium" Test-). 4.1.1 hCjective. The objective is to determine the resistance to penetration of various armor

  14. Laminate armor and related methods

    SciTech Connect

    Chu, Henry S; Lillo, Thomas M; Zagula, Thomas M

    2013-02-26

    Laminate armor and methods of manufacturing laminate armor. Specifically, laminate armor plates comprising a commercially pure titanium layer and a titanium alloy layer bonded to the commercially pure titanium outer layer are disclosed, wherein an average thickness of the titanium alloy inner layer is about four times an average thickness of the commercially pure titanium outer layer. In use, the titanium alloy layer is positioned facing an area to be protected. Additionally, roll-bonding methods for manufacturing laminate armor plates are disclosed.

  15. The armored warriors of kaya

    NASA Astrophysics Data System (ADS)

    Pak, Yangjin

    1995-01-01

    Due to the custom of burying the dead with their weapons, battle armor, and other luxury goods, Korean archaeologists have discovered many examples of iron armor produced and used in Kaya Based on these rick data, a relatively clear picture of the evolution of Kaya iron body armor and helmets from the fourth century to the sixth century has Been developed.

  16. Armor Plate Surface Roughness Measurements

    DTIC Science & Technology

    2005-04-01

    Armor Plate Surface Roughness Measurements by Brian Stanton, William Coburn, and Thomas J. Pizzillo ARL-TR-3498 April 2005... Armor Plate Surface Roughness Measurements Brian Stanton, William Coburn and Thomas J. Pizzillo Sensors and Electron Devices Directorate...October 2004 5a. CONTRACT NUMBER 5b. GRANT NUMBER 4. TITLE AND SUBTITLE Armor Plate Surface Roughness Measurements 5c. PROGRAM ELEMENT NUMBER

  17. Flexible Dermal Armor in Nature

    NASA Astrophysics Data System (ADS)

    Yang, Wen; Chen, Irene H.; Mckittrick, Joanna; Meyers, Marc A.

    2012-04-01

    Many animals possess dermal armor, which acts primarily as protection against predators. We illustrate this through examples from both our research and the literature: alligator, fish (alligator gar, arapaima, and Senegal bichir), armadillo, leatherback turtle, and a lizard, the Gila monster. The dermal armor in these animals is flexible and has a hierarchical structure with collagen fibers joining mineralized units (scales, tiles, or plates). This combination significantly increases the strength and flexibility in comparison with a simple monolithic mineral composite or rigid dermal armor. This dermal armor is being studied for future bioinspired armor applications providing increased mobility.

  18. RNAcentral: an international database of ncRNA sequences

    SciTech Connect

    Williams, Kelly Porter

    2014-10-28

    The field of non-coding RNA biology has been hampered by the lack of availability of a comprehensive, up-to-date collection of accessioned RNA sequences. Here we present the first release of RNAcentral, a database that collates and integrates information from an international consortium of established RNA sequence databases. The initial release contains over 8.1 million sequences, including representatives of all major functional classes. A web portal (http://rnacentral.org) provides free access to data, search functionality, cross-references, source code and an integrated genome browser for selected species.

  19. Advanced Ceramic Armor Materials

    DTIC Science & Technology

    1990-05-11

    materials, toughened alumina, fiber -reinforced glass matrix composites, and multilayer-gradient materials for ballistic testing. Fabrication and...material systems: Multilayer advanced armor materials consisting of a hard ceramic faceplate bonded to a graphite fiber -reinforced glass matrix...toughened alumina, and fiber - applied studies of advanced reinforced ceramic matrix glass and glass -ceramic composites for ballistic testing. technologies

  20. Embedded-monolith armor

    DOEpatents

    McElfresh, Michael W.; Groves, Scott E; Moffet, Mitchell L.; Martin, Louis P.

    2016-07-19

    A lightweight armor system utilizing a face section having a multiplicity of monoliths embedded in a matrix supported on low density foam. The face section is supported with a strong stiff backing plate. The backing plate is mounted on a spall plate.

  1. RNAcentral: A vision for an international database of RNA sequences

    PubMed Central

    Bateman, Alex; Agrawal, Shipra; Birney, Ewan; Bruford, Elspeth A.; Bujnicki, Janusz M.; Cochrane, Guy; Cole, James R.; Dinger, Marcel E.; Enright, Anton J.; Gardner, Paul P.; Gautheret, Daniel; Griffiths-Jones, Sam; Harrow, Jen; Herrero, Javier; Holmes, Ian H.; Huang, Hsien-Da; Kelly, Krystyna A.; Kersey, Paul; Kozomara, Ana; Lowe, Todd M.; Marz, Manja; Moxon, Simon; Pruitt, Kim D.; Samuelsson, Tore; Stadler, Peter F.; Vilella, Albert J.; Vogel, Jan-Hinnerk; Williams, Kelly P.; Wright, Mathew W.; Zwieb, Christian

    2011-01-01

    During the last decade there has been a great increase in the number of noncoding RNA genes identified, including new classes such as microRNAs and piRNAs. There is also a large growth in the amount of experimental characterization of these RNA components. Despite this growth in information, it is still difficult for researchers to access RNA data, because key data resources for noncoding RNAs have not yet been created. The most pressing omission is the lack of a comprehensive RNA sequence database, much like UniProt, which provides a comprehensive set of protein knowledge. In this article we propose the creation of a new open public resource that we term RNAcentral, which will contain a comprehensive collection of RNA sequences and fill an important gap in the provision of biomedical databases. We envision RNA researchers from all over the world joining a federated RNAcentral network, contributing specialized knowledge and databases. RNAcentral would centralize key data that are currently held across a variety of databases, allowing researchers instant access to a single, unified resource. This resource would facilitate the next generation of RNA research and help drive further discoveries, including those that improve food production and human and animal health. We encourage additional RNA database resources and research groups to join this effort. We aim to obtain international network funding to further this endeavor. PMID:21940779

  2. AC-130H Gunship Armor Upgrade Project

    SciTech Connect

    Shell, T.E.; Landingham, R.L.

    1990-09-19

    This report covers the test methods and equipment for testing aircraft armor both hard and soft. The hard armor are the typical ceramic type while the soft armor are various types of layered composite materials. 10 figs. (JEF)

  3. Armor in Vietnam

    DTIC Science & Technology

    1976-05-01

    psychological atmosphere of conventional combat and recall the French experience of 1953 and 1954. It is not clear why creating an impression of...Season Going1 1 Corpr I CORPS . WET SEASON DANo " NO 0O, TK-APC O 50 100 KILOMETERG , .-... Wet Season Going, I Corps •[. FIGUIME 16, KEY: "GOTK-APC...version of the U.S. M48; first pro- 1duced in 1953 , the M48A3 was the primary weapon of U.S. tank battalions and armored cavalry units in Vietnam

  4. Glass matrix armor

    DOEpatents

    Calkins, Noel C.

    1991-01-01

    An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.

  5. Armored garment for protecting

    DOEpatents

    Purvis, James W.; Jones, II, Jack F.; Whinery, Larry D.; Brazfield, Richard; Lawrie, Catherine; Lawrie, David; Preece, Dale S.

    2009-08-11

    A lightweight, armored protective garment for protecting an arm or leg from blast superheated gases, blast overpressure shock, shrapnel, and spall from a explosive device, such as a Rocket Propelled Grenade (RPG) or a roadside Improvised Explosive Device (IED). The garment has a ballistic sleeve made of a ballistic fabric, such as an aramid fiber (e.g., KEVLAR.RTM.) cloth, that prevents thermal burns from the blast superheated gases, while providing some protection from fragments. Additionally, the garment has two or more rigid armor inserts that cover the upper and lower arm and protect against high-velocity projectiles, shrapnel and spall. The rigid inserts can be made of multiple plies of a carbon/epoxy composite laminate. The combination of 6 layers of KEVLAR.RTM. fabric and 28 plies of carbon/epoxy laminate inserts (with the inserts being sandwiched in-between the KEVLAR.RTM. layers), can meet the level IIIA fragmentation minimum V.sub.50 requirements for the US Interceptor Outer Tactical Vest.

  6. Ballistic Testing of Armor Weldments

    DTIC Science & Technology

    1994-01-21

    Distribution unlimited %1 , A E S K T 5A •+ T K .4/ ¢ C+’ •; T . . .. This TOP describes ballistic tests to evaluate armor weldments for resistance to shock and...C-I 1. SCOPE. This TOP describes ballistic tests to evaluate armor weldments for resistance to shock and penetration...Operations Procedure (TOP) 2-2-711 Ballistic Testing of Armor Weldments WU A268445 6+ AuT I`S’•,+ r:’ 7. PERFORMING ORGANIZATION NAME(S) ANU; ADDRCSSI’t

  7. User s Manual for Armor Stone Evaluation Model (ARMOR): Great Lakes Armor Stone Study

    DTIC Science & Technology

    2015-08-01

    MCNP) Program Great Lakes Armor Stone Rapid Deterioration work unit ERDC TR-15-6 ii Abstract Protecting entrances to navigation channels or...resources of CHL and the District and/or Division. 1.2 Purpose of the study Protecting entrances to navigation channels, harbors, or other coastal...used as an optimizing tool to determine how oversized an armor stone should initially be to still provide the desired level of protection after the

  8. Ballistic Testing of Personnel Armor Materials

    DTIC Science & Technology

    1975-01-06

    Identity by block number) 7e)scribes methods for evaluating the resistance of personnel armor material. to perforation by attacking projectile fragments... armor vests, face shields , torso shield , leg armor , and protective suits. It is relatively light in weight, usually between 1/4 and 4 pounds per square...quantitative measures of the ability of body armor materials to completely stop or reduce the velocity (therefore lethality) of attacking fragments of various

  9. Armor and Anesthesia

    PubMed Central

    MacLeish, Kenneth T.

    2013-01-01

    For many civilians, the high-tech weapons, armor, and military medicine with which U.S. soldiers are equipped present an image of lethal capacity and physical invulnerability. But, as this article explores, soldiers themselves just as often associate the life-sustaining technology of modern warfare with feelings that range from a pragmatic ambivalence about exposure to harm all the way to profoundly unsettling vulnerability. This article, based on fieldwork among soldiers and military families at the U.S. Army’s Ft. Hood, examines sensory and affective dimensions of soldiers’ intimate bodily relationships with the technologies that alternately or even simultaneously keep them alive and expose them to harm. I argue that modern military discipline and technology conspire to cultivate soldiers as highly durable, capable, unfeeling, interchangeable bodies, or what might be called, after Susan Buck-Morss (1992), anesthetic subjects. But for soldiers themselves, their training, combat environment, protective gear, and weapons are a rich font of both emotional and bodily feeling that exists in complex tension with the also deeply felt military imperative to carry on in the face of extreme discomfort and danger. PMID:22574391

  10. Typical Reactive Armor Safety Tests

    DTIC Science & Technology

    1993-04-02

    way. etc.). c. Penetration measurements into the backup armor of the dynamic or static rounds (i.e., partial or comple e penetration, depth of...ZP Oe) Alberdeen Prc~ving Ground , MD 21005-5059 Aberdeen Proving Ground , HD 21005-5055 as NAVE 0ýu- TLD,%G 57ON5ORNG 16 (VEif N8 9...OPFJPATIONS PROCEDURE AMSTE-RP-702-10 Test Operatiuns Procedure (TOP) 2-2-623 AD No. 2 April 1993 TYPICAL REACTIVE ARMOR SAFETY TESTS Paragraph 1

  11. Effectiveness of eye armor during blast loading.

    PubMed

    Bailoor, Shantanu; Bhardwaj, Rajneesh; Nguyen, Thao D

    2015-11-01

    Ocular trauma is one of the most common types of combat injuries resulting from the interaction of military personnel with improvised explosive devices. Ocular blast injury mechanisms are complex, and trauma may occur through various injury mechanisms. However, primary blast injuries (PBI) are an important cause of ocular trauma that may go unnoticed and result in significant damage to internal ocular tissues and visual impairment. Further, the effectiveness of commonly employed eye armor, designed for ballistic and laser protection, in lessening the severity of adverse blast overpressures (BOP) is unknown. In this paper, we employed a three-dimensional (3D) fluid-structure interaction computational model for assessing effectiveness of the eye armor during blast loading on human eyes and validated results against free field blast measurements by Bentz and Grimm (2013). Numerical simulations show that the blast waves focused on the ocular region because of reflections from surrounding facial features and resulted in considerable increase in BOP. We evaluated the effectiveness of spectacles and goggles in mitigating the pressure loading using the computational model. Our results corroborate experimental measurements showing that the goggles were more effective than spectacles in mitigating BOP loading on the eye. Numerical results confirmed that the goggles significantly reduced blast wave penetration in the space between the armor and the eyes and provided larger clearance space for blast wave expansion after penetration than the spectacles. The spectacles as well as the goggles were more effective in reducing reflected BOP at higher charge mass because of the larger decrease in dynamic pressures after the impact. The goggles provided greater benefit of reducing the peak pressure than the spectacles for lower charge mass. However, the goggles resulted in moderate, sustained elevated pressure loading on the eye, that became 50-100% larger than the pressure loading

  12. Fast Flexible Modeling of RNA Structure Using Internal Coordinates

    PubMed Central

    Flores, Samuel Coulbourn; Sherman, Michael A.; Bruns, Christopher M.; Eastman, Peter; Altman, Russ Biagio

    2015-01-01

    Modeling the structure and dynamics of large macromolecules remains a critical challenge. Molecular dynamics (MD) simulations are expensive because they model every atom independently, and are difficult to combine with experimentally derived knowledge. Assembly of molecules using fragments from libraries relies on the database of known structures and thus may not work for novel motifs. Coarse-grained modeling methods have yielded good results on large molecules but can suffer from difficulties in creating more detailed full atomic realizations. There is therefore a need for molecular modeling algorithms that remain chemically accurate and economical for large molecules, do not rely on fragment libraries, and can incorporate experimental information. RNABuilder works in the internal coordinate space of dihedral angles and thus has time requirements proportional to the number of moving parts rather than the number of atoms. It provides accurate physics-based response to applied forces, but also allows user-specified forces for incorporating experimental information. A particular strength of RNABuilder is that all Leontis-Westhof basepairs can be specified as primitives by the user to be satisfied during model construction. We apply RNABuilder to predict the structure of an RNA molecule with 160 bases from its secondary structure, as well as experimental information. Our model matches the known structure to 10.2 Angstroms RMSD and has low computational expense. PMID:21778523

  13. Mapping Optimal Charge Density and Length of ROMP-Based PTDMs for siRNA Internalization.

    PubMed

    Caffrey, Leah M; deRonde, Brittany M; Minter, Lisa M; Tew, Gregory N

    2016-10-10

    A fundamental understanding of how polymer structure impacts internalization and delivery of biologically relevant cargoes, particularly small interfering ribonucleic acid (siRNA), is of critical importance to the successful design of improved delivery reagents. Herein we report the use of ring-opening metathesis polymerization (ROMP) methods to synthesize two series of guanidinium-rich protein transduction domain mimics (PTDMs): one based on an imide scaffold that contains one guanidinium moiety per repeat unit, and another based on a diester scaffold that contains two guanidinium moieties per repeat unit. By varying both the degree of polymerization and, in effect, the relative number of cationic charges in each PTDM, the performances of the two ROMP backbones for siRNA internalization were evaluated and compared. Internalization of fluorescently labeled siRNA into Jurkat T cells demonstrated that fluorescein isothiocyanate (FITC)-siRNA internalization had a charge content dependence, with PTDMs containing approximately 40 to 60 cationic charges facilitating the most internalization. Despite this charge content dependence, the imide scaffold yielded much lower viabilities in Jurkat T cells than the corresponding diester PTDMs with similar numbers of cationic charges, suggesting that the diester scaffold is preferred for siRNA internalization and delivery applications. These developments will not only improve our understanding of the structural factors necessary for optimal siRNA internalization, but will also guide the future development of optimized PTDMs for siRNA internalization and delivery.

  14. Advancing viral RNA structure prediction: measuring the thermodynamics of pyrimidine-rich internal loops.

    PubMed

    Phan, Andy; Mailey, Katherine; Sakai, Jessica; Gu, Xiaobo; Schroeder, Susan J

    2017-02-17

    Accurate thermodynamic parameters improve RNA structure predictions and thus accelerate understanding of RNA function and the identification of RNA drug binding sites. Many viral RNA structures, such as internal ribosome entry sites, have internal loops and bulges that are potential drug target sites. Current models used to predict internal loops are biased towards small, symmetric purine loops, and thus poorly predict asymmetric, pyrimidine-rich loops with more than 6 nucleotides that occur frequently in viral RNA. This paper presents new thermodynamic data for 40 pyrimidine loops, many of which can form UU or protonated CC base pairs. Protonated cytosine and uracil base pairs stabilize asymmetric internal loops. Accurate prediction rules are presented that account for all thermodynamic measurements of RNA asymmetric internal loops. New loop initiation terms for loops with more than 6 nucleotides are presented that do not follow previous assumptions that increasing asymmetry destabilizes loops. Since the last 2004 update, 126 new loops with asymmetry or sizes greater than 2x2 have been measured (Mathews 2004). These new measurements significantly deepen and diversify the thermodynamic database for RNA. These results will help better predict internal loops that are larger, pyrimidine-rich, and occur within viral structures such as internal ribosome entry sites.

  15. BASELINE UT MEASUREMENTS FOR ARMOR INSPECTION

    SciTech Connect

    Margetan, Frank J.; Richter, Nate; Barnard, Dan; Hsu, David; Gray, Tim; Brasche, Lisa; Bruce Thompson, R.

    2010-02-22

    Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties can be used when choosing an optimum frequency for an ultrasonic pitch/catch immersion inspection. In our case an effective inspection frequency near 1.5 MHz affords: (1) adequate strength of through-transmitted signals in unflawed armor; (2) adequate lateral resolution for detecting small disbonds at interfaces; and (3) low levels of UT signal fluctuations due to the natural inhomogeneity of certain armor layers. The utility of this approach is demonstrated using armor panels containing artificial disbonds at selected interfaces.

  16. Patterned Armor Performance Evaluation for Multiple Impacts

    DTIC Science & Technology

    2003-08-01

    return it to the originator. Army Research Laboratory Aberdeen Proving Ground , MD 21005-5069 ARL-TR-3038 August 2003 Patterned Armor ...patterned armor performance against multiple impacts. This performance measure can then be compared to a well-posed multiple-hit criterion to assess...Aberdeen Proving Ground , MD, September 2002. de Rosset, W. S. Reactive Armor Model Sensitivity Studies; ARL-TR-1849; U.S. Army Research Laboratory

  17. US Army History and Role of Armor

    DTIC Science & Technology

    1974-04-01

    Army armor mobile ground warfare, primarily offensive in units to achieve success in later battles. From character, by a self-sustaining unit of great... Armored was rain, and stubborn enemy resistance caused on a 6-hour alert. When the opportunity pre- the VI Corps to go over to the defensive on sented...were slow, War II were the major ground reconnaissance support-type actions without the spectacular units in our Army. They were lightly armored success

  18. Sensor Enhanced Armor Non Destructive Evaluation Laboratory

    DTIC Science & Technology

    2009-08-11

    multiple layers) Phased Array Ultrasonic Scanning in H20 Handheld Prototype Testing Device Embedded sensors Unclassified X-ray and mm wave image of...NDT/ NDE Laboratory Unclassified Vehicle Display Views – Healthy Armor Unclassified NDE of Transparent Materials Phased Array Ultrasound Image...Provide ultrasonic , x-ray and mmwave imaging for armor damage analysis. • Explore various NDE options to support all armor recipies Objective: • Provide

  19. Multiscale Modeling of Armor Ceramics: Focus on AlON

    DTIC Science & Technology

    2011-09-01

    2003: Multiple Material Marching Cubes Algorithm . Int. J. Numer . Meth. Eng., 58(2), 189–207. NO. OF COPIES ORGANIZATION 9 1 DEFENSE...Army Science Conference, Orlando, FL, 29 November–2 December 2010. 14. ABSTRACT The computational modeling linkage from the atomistic to the...controlled processing. This report will review results from an internal multiscale computational program in first-principles design of armor ceramics

  20. Armored Multi Purpose Vehicle (AMPV)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-471 Armored Multi-Purpose Vehicle (AMPV) As of FY 2017 President’s Budget Defense Acquisition...RDT&E - Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then...RDT&E funding by $4M assigned to Program Management Growth. While this decrement will cause a slight re-prioritization of selected efforts in FY 2016

  1. Collaborative study for the calibration of HCV RNA, HBV DNA and HIV RNA reference preparations against the relative international standards.

    PubMed

    Pisani, Giulio; Marino, Francesco; Cristiano, Karen; Bisso, Guillermo Mario; Mele, Caludio; Luciani, Francesca; Wirz, Maria; Gentili, Giuliano

    2007-01-01

    We organised a collaborative study to calibrate three new ISS reference preparations (ISS: Istituto Superiore di Sanità), one for HCV RNA, one for HIV RNA and one for HBV DNA, to be used for nucleic acid amplification techniques (NAT) in blood testing. Serial dilution of the ISS reference preparations and the respective international standards were tested in different days by each participating laboratory using two commercial NAT assays. Data were collected by the ISS for statistical analysis. Based on the mean potency of the HCV RNA and HIV RNA preparations, calculated from the results provided by the 12 participating laboratories, a definitive concentrations of 5700 IU/mL and 4000 IU/mL, respectively, were assigned to the reference materials. On the contrary, it was not possible to obtain a consensus titre for the HBV DNA reference material. These new Italian reference preparations (HCV RNA ISS/1005 and HIV RNA ISS/1005) calibrated against the respective international standards are available free of charge to any laboratory upon request.

  2. Procurement Policy for Armored Vehicles

    DTIC Science & Technology

    2007-06-27

    AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11 . SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT...Specifically, DoD awarded 11 sole-source contracts, valued at $416.7 million, to Force Protection, Inc., for armored vehicles and 4 sole-source contracts...Shaw Air Force Base was the contracting activity for the AHI contract with the Air Force. DoD Contracts With FPI. DoD awarded 11 contracts to FPI

  3. Does HIV-1 mRNA 5'-untranslated region bear an internal ribosome entry site?

    PubMed

    Smirnova, Victoria V; Terenin, Ilya M; Khutornenko, Anastasia A; Andreev, Dmitri E; Dmitriev, Sergey E; Shatsky, Ivan N

    2016-02-01

    Unspliced human immunodeficiency virus-1 (HIV-1) mRNA is capped and therefore can be translated via conventional scanning mechanism. In addition, its 5' untranslated region (5'UTR) is thought to function as an internal ribosome entry site (IRES) during G2/M-phase of cell cycle or when cap-dependent translation is inhibited. Recently, customary methods of internal initiation demonstrating have been challenged, and consequently existence of certain IRESs of cellular origin has been put under question. Since a precise knowledge of translation initiation mechanism used by HIV may be important for cure development, presence of the IRES in HIV-1 mRNA demands a careful reexamination using contemporary stringent criteria. The key point of our strategy is to compare translation efficiency of bicistronic mRNA bearing HIV-1 unspliced mRNA 5' UTR in the intercistronic position to that of the corresponding capped monocistronic mRNA. This approach allows determination of internal initiation contribution into the overall level of particular mRNA translation. We found that both in cell-free systems and in cultured cells monocistronic mRNA with HIV-1 unspliced mRNA 5'UTR is translated significantly better than bicistronic one. Importantly, it is also true for G2/M-phase stalled cells or for cells under conditions of inhibited cap-dependent translation. Thus, in our hands contribution of internal ribosome entry into the overall level of translation driven by HIV-1 unspliced mRNA 5'UTR is negligible, and 5'-dependent scanning is a primary mechanism of its translation initiation.

  4. Complex RNA maturation pathway for a chloroplast ribosomal protein operon with an internal tRNA cistron.

    PubMed Central

    Christopher, D A; Hallick, R B

    1990-01-01

    We have studied the expression of a large chloroplast ribosomal protein operon from Euglena gracilis that resembles the Escherichia coli S10 and spc ribosomal protein operons. We present evidence that 11 ribosomal protein genes, a tRNA gene, and a new locus, orf214/orf302, are expressed as a single transcription unit. The primary transcript also contains at least 15 group II and group III introns. Gene-specific probes for each ribosomal protein gene, orf214/orf302, and for trnl hybridized to a common pre-mRNA of an estimated size of 8.3 kilobases. This is the RNA size predicted for a full-length transcript of the entire operon after splicing of all 15 introns. Polycistronic ribosomal protein mRNAs accumulated primarily as spliced hepta-, hexa-, penta-, tetra-, tri-, and dicistronic mRNAs, which were presumed to arise by stepwise processing of the 8.3-kilobase pre-mRNA. A novel finding was the cotranscription of the trnl gene as an internal cistron within the ribosomal protein operon. Several combined mRNA/tRNA molecules, such as the pentacistronic rpl5-rps8-rpl36-trnl-rps14, were characterized. The occurrence of the orf214/orf302 is a unique feature of the Euglena operon, distinguishing it from all chloroplast and prokaryotic ribosomal protein operons characterized to date. The orf214/orf302 are not similar to any known genes but are cotranscribed with the ribosomal protein loci and encode stable RNA species of 2.4, 1.8, and 1.4 kilobases. PMID:2136640

  5. U.S. Army Armor in Limited War: Armor Employment Techniques in Korea and Vietnam

    DTIC Science & Technology

    1987-05-29

    destroyed in battle.2 But a point had been made: armor could be employed effectively in Korea. Fifteen years later, American ground units deployed for the...Cavalry units, however, largely fought with the M113 Armored Personnel Carrier (APC) which they modified by attaching gun shields for its .50-caliber... ground operations in both wars, for the purposes of comparison, will be considered in three categories - offensive operations; armor or mounted units

  6. Fit Evaluation of Female Body Armor

    DTIC Science & Technology

    1987-06-01

    AAM1oRL-TR7-06 %lC JLL~ J FIT EVALUATION OF FEMALE BODY ARMOR (U) AD-A 188 721 - GREGORY E ZEHNER ARMSTRONG AEROSPACE MEDICAL RESEARCH LABORATORY CAY...Security Classification) Fit Evaluation of Female Body Armor (U) 12. PERSONAL AUTHOR(S) Zehner, Gregory F.*; Ervin, Cay; Robinette, Kathleen M.*; and...Continue on reverse If necessary and Identify by block number) FIELD GROUP SUB-GROUP Female body armor Fit/protection Vests Fit testing 19. ABSTRACT

  7. Conformable Self-Healing Ballistic Armor

    DTIC Science & Technology

    2011-06-28

    armor piercing projectiles even from military rifles rep- which initiates a crack , the ceramic material will undergo continuous cracking or crazing ...part of ballistic protective armor systems is well-known because of the light weight of these materials as compared to steel and other solid...aUoy steel which provides protection against most heavy and explosive particles. Such 10 vehicles or vessels are frequently capable of selectively

  8. World Health Organization International Standard to Harmonize Assays for Detection of Hepatitis E Virus RNA

    PubMed Central

    Blümel, Johannes; Mizusawa, Saeko; Matsubayashi, Keiji; Sakata, Hidekatsu; Okada, Yoshiaki; Nübling, C. Micha; Hanschmann, Kay-Martin O.

    2013-01-01

    Nucleic acid amplification technique–based assays are a primary method for the detection of acute hepatitis E virus (HEV) infection, but assay sensitivity can vary widely. To improve interlaboratory results for the detection and quantification of HEV RNA, a candidate World Health Organization (WHO) International Standard (IS) strain was evaluated in a collaborative study involving 23 laboratories from 10 countries. The IS, code number 6329/10, was formulated by using a genotype 3a HEV strain from a blood donation, diluted in pooled human plasma and lyophilized. A Japanese national standard, representing a genotype 3b HEV strain, was prepared and evaluated in parallel. The potencies of the standards were determined by qualitative and quantitative assays. Assay variability was substantially reduced when HEV RNA concentrations were expressed relative to the IS. Thus, WHO has established 6329/10 as the IS for HEV RNA, with a unitage of 250,000 International Units per milliliter. PMID:23647659

  9. Nuclear rRNA transcript processing versus internal transcribed spacer secondary structure.

    PubMed

    Coleman, Annette W

    2015-03-01

    rRNA is one of the few universal features of life, making it uniquely suited to assess phylogenetic relationships. The processing of the initial polycistronic rRNA transcript is also a conserved process, involving numerous cleavage events and the generation of secondary structures. The secondary structure of the internal transcribed spacer (ITS) regions of nuclear rRNA transcripts are well known for a wide variety of eukaryotes and have been used to aid in the alignment of these sequences for phylogenetic comparisons. By contrast, study of the processing of the initial rRNA transcripts has been largely limited to yeast, mice, rats, and humans. Here I examine the known cleavage sites in the two ITS regions and their positions relative to the secondary structure. A better understanding of the conservation of secondary structures and cleavage sites within the ITS regions will improve evolutionary inferences based on these sequences.

  10. Structure of Ty1 Internally Initiated RNA Influences Restriction Factor Expression.

    PubMed

    Błaszczyk, Leszek; Biesiada, Marcin; Saha, Agniva; Garfinkel, David J; Purzycka, Katarzyna J

    2017-04-10

    The long-terminal repeat retrotransposon Ty1 is the most abundant mobile genetic element in many Saccharomyces cerevisiae isolates. Ty1 retrotransposons contribute to the genetic diversity of host cells, but they can also act as an insertional mutagen and cause genetic instability. Interestingly, retrotransposition occurs at a low level despite a high level of Ty1 RNA, even though S. cerevisiae lacks the intrinsic defense mechanisms that other eukaryotes use to prevent transposon movement. p22 is a recently discovered Ty1 protein that inhibits retrotransposition in a dose-dependent manner. p22 is a truncated form of Gag encoded by internally initiated Ty1i RNA that contains two closely-spaced AUG codons. Mutations of either AUG codon compromise p22 translation. We found that both AUG codons were utilized and that translation efficiency depended on the Ty1i RNA structure. Structural features that stimulated p22 translation were context dependent and present only in Ty1i RNA. Destabilization of the 5' untranslated region (5' UTR) of Ty1i RNA decreased the p22 level, both in vitro and in vivo. Our data suggest that protein factors such as Gag could contribute to the stability and translational activity of Ty1i RNA through specific interactions with structural motifs in the RNA.

  11. Internal Initiation of Translation of mRNA in the Methylotrophic Yeast Hansenula polymorpha.

    PubMed

    Mardanova, E S; Beletsky, A V; Ravin, N V

    2016-05-01

    Besides regular cap-dependent translation of mRNA, eukaryotes exploit internal initiation of translation driven by internal ribosome entry sites (IRESs). It is supposed that internal initiation provides translation of cellular mRNAs under stress conditions where the cap-dependent initiation is reduced. A number of IRESs have been characterized in mammalian mRNAs, but only a few examples are known in lower eukaryotes, particularly in yeasts. Here we identified two IRESs in the thermotolerant methylotrophic yeast Hansenula polymorpha DL-1. These sites are located in 5'-untranslated regions of genes HPODL_02249 and HPODL_04025 encoding a hypothetical membrane protein and actin-binding protein, respectively. In Saccharomyces cerevisiae cells, both IRESs drive expression of a second gene of a bicistronic mRNA, as well as translation of hairpin-containing monocistronic mRNA. The possibility of spurious splicing or presence of a cryptic promoter in the IRES sequences was ruled out, indicating that expression of a second gene of a bicistronic mRNA was IRES-dependent. We evaluated IRES activity of both elements and found that under normal physiological conditions its contribution to the overall translation of the respective mRNAs in yeast cells is about 0.3-0.4%. Therefore, these results suggest that the IRES-dependent translation initiation mechanism exists in Hansenula polymorpha.

  12. Armored Battle Groups in the 21st Century

    DTIC Science & Technology

    1989-03-31

    ARMORED BATTLE GROUPS IN THE 21ST CENTURY BY LIEUTENANT COLONEL WENDELL D. KOT )STIRUMtN STATE9M A: Approved fer public releft. distribution is izulatated...RECIPIENT’S CATALOG NUMBER 4. TITLE (’ Subtitle) 5. TYPE OF REPORT & PERIOD COVERED ARMORED BATTLE GROUPS IN THE 21ST CENTURY i Individual Study Project 6...alternative to today’s heavy division force structure - Armored Battle Groups is examined. The Armored Battle Group organization devel- oped in the paper

  13. RNA internal standard synthesis by nucleic acid sequence-based amplification for competitive quantitative amplification reactions.

    PubMed

    Lo, Wan-Yu; Baeumner, Antje J

    2007-02-15

    Nucleic acid sequence-based amplification (NASBA) reactions have been demonstrated to successfully synthesize new sequences based on deletion and insertion reactions. Two RNA internal standards were synthesized for use in competitive amplification reactions in which quantitative analysis can be achieved by coamplifying the internal standard with the wild type sample. The sequences were created in two consecutive NASBA reactions using the E. coli clpB mRNA sequence as model analyte. The primer sequences of the wild type sequence were maintained, and a 20-nt-long segment inside the amplicon region was exchanged for a new segment of similar GC content and melting temperature. The new RNA sequence was thus amplifiable using the wild type primers and detectable via a new inserted sequence. In the first reaction, the forwarding primer and an additional 20-nt-long sequence was deleted and replaced by a new 20-nt-long sequence. In the second reaction, a forwarding primer containing as 5' overhang sequence the wild type primer sequence was used. The presence of pure internal standard was verified using electrochemiluminescence and RNA lateral-flow biosensor analysis. Additional sequence deletion in order to shorten the internal standard amplicons and thus generate higher detection signals was found not to be required. Finally, a competitive NASBA reaction between one internal standard and the wild type sequence was carried out proving its functionality. This new rapid construction method via NASBA provides advantages over the traditional techniques since it requires no traditional cloning procedures, no thermocyclers, and can be completed in less than 4 h.

  14. Defining the RNA internal loops preferred by benzimidazole derivatives via 2D combinatorial screening and computational analysis.

    PubMed

    Velagapudi, Sai Pradeep; Seedhouse, Steven J; French, Jonathan; Disney, Matthew D

    2011-07-06

    RNA is an important therapeutic target; however, RNA targets are generally underexploited due to a lack of understanding of the small molecules that bind RNA and the RNA motifs that bind small molecules. Herein, we describe the identification of the RNA internal loops derived from a 4096 member 3 × 3 nucleotide loop library that are the most specific and highest affinity binders to a series of four designer, druglike benzimidazoles. These studies establish a potentially general protocol to define the highest affinity and most specific RNA motif targets for heterocyclic small molecules. Such information could be used to target functionally important RNAs in genomic sequence.

  15. Armor: Metallurgical Examination of Cast Gun Shield Armor Four to Six Inches in Thickness

    DTIC Science & Technology

    1943-05-17

    thick cast armor plates to Aberdeen Proving Ground for ballistic testin?. Thesp plates represent sections of gun shield castings. Sev^rpl of ths...1+6 UNCLASSIFIED May 17. 19^3 ABhOR Metallurgical Exajnination of Cast Gun Shield Armor Four to Six Inches in Thickness •le. ■ ■ r/^OBJECT 1...T^TTT 1 ::t^’*jom ATiEIALS ülT3 TEST PROCEM] Cast Armor Sections Sections cut from 10 test plates representing gun shield castings were examined

  16. Visualization of self-delivering hydrophobically modified siRNA cellular internalization

    PubMed Central

    Ly, Socheata; Navaroli, Deanna M.; Didiot, Marie-Cécile; Cardia, James; Pandarinathan, Lakshmipathi; Alterman, Julia F.; Fogarty, Kevin; Standley, Clive; Lifshitz, Lawrence M.; Bellve, Karl D.; Prot, Matthieu; Echeverria, Dimas; Corvera, Silvia; Khvorova, Anastasia

    2017-01-01

    siRNAs are a new class of therapeutic modalities with promising clinical efficacy that requires modification or formulation for delivery to the tissue and cell of interest. Conjugation of siRNAs to lipophilic groups supports efficient cellular uptake by a mechanism that is not well characterized. Here we study the mechanism of internalization of asymmetric, chemically stabilized, cholesterol-modified siRNAs (sd-rxRNAs®) that efficiently enter cells and tissues without the need for formulation. We demonstrate that uptake is rapid with significant membrane association within minutes of exposure followed by the formation of vesicular structures and internalization. Furthermore, sd-rxRNAs are internalized by a specific class of early endosomes and show preferential association with epidermal growth factor (EGF) but not transferrin (Tf) trafficking pathways as shown by live cell TIRF and structured illumination microscopy (SIM). In fixed cells, we observe ∼25% of sd-rxRNA co-localizing with EGF and <5% with Tf, which is indicative of selective endosomal sorting. Likewise, preferential sd-rxRNA co-localization was demonstrated with EEA1 but not RBSN-containing endosomes, consistent with preferential EGF-like trafficking through EEA1-containing endosomes. sd-rxRNA cellular uptake is a two-step process, with rapid membrane association followed by internalization through a selective, saturable subset of the endocytic process. However, the mechanistic role of EEA1 is not yet known. This method of visualization can be used to better understand the kinetics and mechanisms of hydrophobic siRNA cellular uptake and will assist in further optimization of these types of compounds for therapeutic intervention. PMID:27899655

  17. Status Report on SPS TiB2/TiB/Ti Functionally Graded Materials (FGMs) for Armor

    DTIC Science & Technology

    2006-09-01

    report is a collection of the charts used for an oral presentation at the 28th International Cocoa Beach Conference and Exposition on Advanced Ceramics...Watervliet, NY Topics in Ceramic Armor 28th International Cocoa Beach Conference and Exposition on Advanced Ceramics and Composites January 27

  18. Resonance and streaming of armored microbubbles

    NASA Astrophysics Data System (ADS)

    Spelman, Tamsin; Bertin, Nicolas; Stephen, Olivier; Marmottant, Philippe; Lauga, Eric

    2015-11-01

    A new experimental technique involves building a hollow capsule which partially encompasses a microbubble, creating an ``armored microbubble'' with long lifespan. Under acoustic actuation, such bubble produces net streaming flows. In order to theoretically model the induced flow, we first extend classical models of free bubbles to describe the streaming flow around a spherical body for any known axisymmetric shape oscillation. A potential flow model is then employed to determine the resonance modes of the armored microbubble. We finally use a more detailed viscous model to calculate the surface shape oscillations at the experimental driving frequency, and from this we predict the generated streaming flows.

  19. From surface to subsurface and back again: the contribution of subsurface particle motion to surface armoring

    NASA Astrophysics Data System (ADS)

    Ferdowsi, B.; Jerolmack, D. J.; Ortiz, C. P.; Houssais, M.

    2015-12-01

    Armoring is the development of a coarse surface layer of sediments on a river bed, which overlies a smaller and typically more heterogeneous substrate. All existing models for this phenomenon are predicated on the idea that armoring develops due to size-selective transport and kinetic sieving at the surface of the granular bed. Here examine the development of armoring in the absence of size-selective surface transport, and demonstrate that subsurface particle movement can create an armored surface layer. We first conduct experiments in a laminar and annular flume, over a range of Shields stresses, with bimodal and refractive index-matched spherical sediments; this allows us to image the internal motion of the granular bed that is sheared from above by a viscous oil. Fluid-driven particle motion of the surface layer results in granular shear, that drives motion deep into the bed. This subsurface motion causes an upward migration of coarser particles, at a rate that is proportional to the granular shear rate. Comparison of experimental results to an existing continuum-granular flow model suggest that armoring in our bed-load exeriments is entirely consistent with shear-induced segregation in dry avalanches - but is slower. There is no size-selective transport at the surface in the experiments, as the annular flume is mass conserving and all particles move as bed load; this was confirmed by observation. To probe the granular physics of armor development further, we perform numerical simulations using a discrete element model (DEM) of granular flow, with and without damping. Simulations reproduce salient features of the experiments, and indicate that armoring is robust but that the rate of segregation is related to the degree of viscous damping. We posit that subsurface granular flow is an important and perhaps dominant contributor to surface armoring in rivers. More generally, this work shows how information is transferred from the surface to the subsurface and back

  20. RNA.

    ERIC Educational Resources Information Center

    Darnell, James E., Jr.

    1985-01-01

    Ribonucleic acid (RNA) converts genetic information into protein and usually must be processed to serve its function. RNA types, chemical structure, protein synthesis, translation, manufacture, and processing are discussed. Concludes that the first genes might have been spliced RNA and that humans might be closer than bacteria to primitive…

  1. Promoting Improved Ballistic Resistance of Transparent Armor

    SciTech Connect

    Wereszczak, Andrew A; Patel, P; Templeton, D W

    2011-01-01

    Transparent armor is a material or system of materials designed to be optically transparent, yet protect from fragmentation or ballistic impacts. Although engineered to defeat specific threats, or a range of threats, there are general requirements common to all of these designs. The primary requirement for a transparent armor system is to not only defeat the designated threat but also provide a multi-hit capability with minimized distortion of surrounding areas. Ground platforms have several parameters that must be optimized, such as weight, space efficiency, and cost versus performance. Glass exhibits tensile failure stress that is very much dependent on the amount of material being stressed, the side being tensile-stressed (i.e., air-versus tin-side if a float glass), and where it is being tensile stressed (i.e., in the middle or near an edge). An axiom arising from those effects is a greater amount of allowable deflection (i.e., higher failure stress) of a ballistically impacted transparent armor will result in improved ballistic resistance. Therefore, the interpretation and management of those tensile-failure-stress dependencies shall ultimately improve ballistic resistance and its predictability of transparent armor. Each of those three dependencies (size, side, and location) in a soda-lime silicate glass is described.

  2. Lightweight Integrally Armored Floor (LIAF) Ballistic Testing

    DTIC Science & Technology

    2011-03-01

    UHMWPE ), and a mini-core sandwich structure which serves as the walking surface of the floor system (Figure 1). Specimen details are covered in...SIDE Strike Face Backing Plate (walking surface) Ballistic Material ( UHMWPE ) Projectile Lightweight Integrally Armored Floor (LIAF

  3. Joining of Tungsten Armor Using Functional Gradients

    SciTech Connect

    John Scott O'Dell

    2006-12-31

    The joining of low thermal expansion armor materials such as tungsten to high thermal expansion heat sink materials has been a major problem in plasma facing component (PFC) development. Conventional planar bonding techniques have been unable to withstand the high thermal induced stresses resulting from fabrication and high heat flux testing. During this investigation, innovative functional gradient joints produced using vacuum plasma spray forming techniques have been developed for joining tungsten armor to copper alloy heat sinks. A model was developed to select the optimum gradient architecture. Based on the modeling effort, a 2mm copper rich gradient was selected. Vacuum plasma pray parameters and procedures were then developed to produce the functional gradient joint. Using these techniques, dual cooling channel, medium scale mockups (32mm wide x 400mm length) were produced with vacuum plasma spray formed tungsten armor. The thickness of the tungsten armor was up to 5mm thick. No evidence of debonding at the interface between the heat sink and the vacuum plasma sprayed material was observed.

  4. Analysis of behind the armor ballistic trauma.

    PubMed

    Wen, Yaoke; Xu, Cheng; Wang, Shu; Batra, R C

    2015-05-01

    The impact response of body armor composed of a ceramic plate with an ultrahigh molecular weight polyethylene (UHMWPE) fiber-reinforced composite and layers of UHMWPE fibers shielding a block of ballistic gelatin has been experimentally and numerically analyzed. It is a surrogate model for studying injuries to human torso caused by a bullet striking body protection armor placed on a person. Photographs taken with a high speed camera are used to determine deformations of the armor and the gelatin. The maximum depth of the temporary cavity formed in the ballistic gelatin and the peak pressure 40mm behind the center of the gelatin front face contacting the armor are found to be, respectively, ~34mm and ~15MPa. The Johnson-Holmquist material model has been used to simulate deformations and failure of the ceramic. The UHMWPE fiber-reinforced composite and the UHMWPE fiber layers are modeled as linear elastic orthotropic materials. The gelatin is modeled as a strain-rate dependent hyperelastic material. Values of material parameters are taken from the open literature. The computed evolution of the temporary cavity formed in the gelatin is found to qualitatively agree with that seen in experiments. Furthermore, the computed time histories of the average pressure at four points in the gelatin agree with the corresponding experimentally measured ones. The maximum pressure at a point and the depth of the temporary cavity formed in the gelatin can be taken as measures of the severity of the bodily injury caused by the impact; e.g. see the United States National Institute of Justice standard 0101.06-Ballistic Resistance of Body Armor.

  5. Task-specific effects of modular body armor.

    PubMed

    Larsen, Brianna; Netto, Kevin; Aisbett, Brad

    2014-04-01

    Eleven recreationally active males performed 11 circuits of military work, wearing torso armor on one occasion, and full armor on another. Performance was measured by the time taken to complete individual tasks, and the overall time to completion (TTC) for each circuit. Heart rate, intestinal temperature, ratings of perceived exertion (RPE), and thermal sensation were recorded after each circuit. Participants' circuit TTC was no different between conditions; however, specific tasks were differentially impeded by the two armor configurations. Vaulting and crawling were significantly slower (0.28 ± 0.06 and 0.55 ± 0.26 seconds) in full armor; however, box lifting and shooting were significantly slower (0.36 ± 0.18 and 0.86 ± 0.23 seconds) when wearing torso armor. Heart rate and core temperature were significantly higher during the full armor trial (5 ± 1 beats · min(-1) and 0.22 ± 0.03 °C). Similarly, RPE and thermal sensation were significantly higher (1 ± 0 and 0.5 ± 0.0) during the full armor condition. Military tasks were differentially impaired by the armor configurations used, which suggests a need to explore role-specific armor for military personnel. Physiological and perceptual responses were elevated in full armor, which could be exacerbated during longer periods of work or in hot conditions.

  6. In vivo efficacy and off-target effects of locked nucleic acid (LNA) and unlocked nucleic acid (UNA) modified siRNA and small internally segmented interfering RNA (sisiRNA) in mice bearing human tumor xenografts.

    PubMed

    Mook, Orf; Vreijling, Jeroen; Wengel, Suzy L; Wengel, Jesper; Zhou, Chuanzheng; Chattopadhyaya, Jyoti; Baas, Frank; Fluiter, Kees

    2010-07-01

    The clinical use of small interfering RNA (siRNA) is hampered by poor uptake by tissues and instability in circulation. In addition, off-target effects pose a significant additional problem for therapeutic use of siRNA. Chemical modifications of siRNA have been reported to increase stability and reduce off-target effects enabling possible therapeutic use of siRNA. Recently a large scale direct comparison of the impact of 21 different types of novel chemical modifications on siRNA efficiency and cell viability was published.1 It was found that several types of chemical modifications could enhance siRNA activity beyond that of an unmodified siRNA in vitro. In addition, a novel siRNA design, termed small internally segmented interfering RNA (sisiRNA), composed of an intact antisense strand and segmented guide strand stabilized using LNA was shown to be effective in cell based assays. In the present study we examined the in vivo efficacy of the LNA and UNA modified siRNA and sisiRNA in a mouse model bearing human tumor xenografts. We studied the biodistribution and efficacy of target knockdown in the mouse model. In addition we used whole genome profiling to assess the off-target effects in the liver of the mouse and the tumor xenografts. We report that LNA and UNA modified siRNA and sisiRNA improve the efficacy in target knockdown as compared with unmodified siRNA in the tumor xenografts without formulation. However, the level of off-target gene regulation in both the tumor and the liver correlated with the increase in efficacy in target knockdown, unless the seed region of the siRNA was modified.

  7. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Expedition 6 crew member Nikolai Budarin stands ready for a practice drive in an M-113 armored personnel carrier during emergency egress training at the pad, one of the Terminal Countdown Demonstration Test activities in preparation for launch. The TCDT also includes a simulated launch countdown. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  8. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Expedition 6 crew member Donald Pettit stands ready for a practice drive in an M-113 armored personnel carrier during emergency egress training at the pad, one of the Terminal Countdown Demonstration Test activities in preparation for launch. The TCDT also includes a simulated launch countdown. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  9. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Expedition 6 crew member Nikolai Budarin takes his turn driving an M-113 armored personnel carrier during emergency egress training at the pad. The crew is preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10, by taking part in Terminal Countdown Demonstration Test activities. The TCDT includes a simulated launch countdown.. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  10. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Expedition 6 Commander Ken Bowersox stands ready for a practice drive in an M-113 armored personnel carrier during emergency egress training at the pad, one of the Terminal Countdown Demonstration Test activities in preparation for launch. The TCDT also includes a simulated launch countdown. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  11. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The Expedition 6 crew pauses for a photo after emergency egress training at the pad, which included driving the M-113 armored personnel carrier behind them. The crew is preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10, by taking part in Terminal Countdown Demonstration Test activities. The TCDT includes a simulated launch countdown.. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  12. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- During emergency egress training at the pad, Expedition 6 crew member Donald Pettit stands inside an M-113 armored personnel carrier before his practice drive. The training is part of Terminal Countdown Demonstration Test activities in preparation for launch. The TCDT also includes a simulated launch countdown. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  13. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Expedition 6 crew member Donald Pettit concentrates on driving an M-113 armored personnel carrier during emergency egress training at the pad. The crew is preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10, by taking part in Terminal Countdown Demonstration Test activities. The TCDT includes a simulated launch countdown.. The Expedition 6 crew will travel on Space Shuttle Endeavour to the International Space Station to replace Expedition 5, returning to Earth after 4 months. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Launch is scheduled for Nov. 10, 2002.

  14. Improved Low-Cost Multi-Hit Transparent Armor

    DTIC Science & Technology

    2006-11-01

    MD Aberdeen Proving Ground , MD 21005-5069 ABSTRACT Operation Iraqi Freedom has clearly demonstrated the criticality of transparent armor in...Motyka at ARL) A polymer backing acts as a spall shield and holds fractured armor in place. Interlayer between polycarbonate and ceramics is...Hsieh, Gary A. Gilde U.S. Army Research Laboratory Aberdeen Proving Ground , MD IMPROVED LOW-COST MULTI-HIT TRANSPARENT ARMOR Distribution A

  15. Soldier Performance Research Project: Armor Field and SIMNET Tests

    DTIC Science & Technology

    1989-09-01

    Event 5. The crew will react to an ATGM ambush. The TC must issue the contact report and fire command (both timed). The tank should take evasive ...Cammand’s (TEXO34) Armor and Engineer Board who conducted the Soldier Performance Research Project (SPRP) Armor tests: MC Royce Simson, Test Director CPI...the Soldier Performance Research Project (SPP), the Armor portion was conducted in two phases to provide a rigorous assessment of the cognitive skill

  16. Embedded Non-Destructive Evaluation for Glass Armor

    DTIC Science & Technology

    2011-12-05

    Unclassified In House NDE and Electromagnetic Compatibility Capabilities Millimeter wave Scanning Imager Phased Array Ultrasound Immersion Tank Low...DISTRIBUTION A: Approved for public release; distribution is unlimited Embedded NDE for Glass Armor Sensor Enhanced Armor- Non-Destructive...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Unclassified Armor Solutions Tested with Ultrasonics NDT/E leading to Sensor Enhanced

  17. Probing a 2-aminobenzimidazole library for binding to RNA internal loops via two-dimensional combinatorial screening.

    PubMed

    Velagapudi, Sai Pradeep; Pushechnikov, Alexei; Labuda, Lucas P; French, Jonathan M; Disney, Matthew D

    2012-11-16

    There are many potential RNA drug targets in bacterial, viral, and human transcriptomes. However, there are few small molecules that modulate RNA function. This is due, in part, to a lack of fundamental understanding about RNA-ligand interactions including the types of small molecules that bind to RNA structural elements and the RNA structural elements that bind to small molecules. In an effort to better understand RNA-ligand interactions, we diversified the 2-aminobenzimidazole core (2AB) and probed the resulting library for binding to a library of RNA internal loops. We chose the 2AB core for these studies because it is a privileged scaffold for binding RNA based on previous reports. These studies identified that N-methyl pyrrolidine, imidazole, and propylamine diversity elements at the R1 position increase binding to internal loops; variability at the R2 position is well tolerated. The preferred RNA loop space was also determined for five ligands using a statistical approach and identified trends that lead to selective recognition.

  18. Constrained ceramic-filled polymer armor

    DOEpatents

    Sandstrom, D.J.; Calkins, N.C.; Gac, F.D.

    1990-11-13

    An armor system is disclosed in which a plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material, which is a ceramic material in particulate form dispersed in a polymeric matrix. 5 figs.

  19. Constrained ceramic-filled polymer armor

    DOEpatents

    Sandstrom, Donald J.; Calkins, Noel C.; Gac, Frank D.

    1990-01-01

    An armor system in which a plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material, which is a ceramic material in particulate form dispersed in a polymeric matrix.

  20. Development of Diagnostics for Electromagnetic Armor Applications

    DTIC Science & Technology

    1992-06-01

    with plate voltage as measured by a standard resistance voltage-divider. It was thought that having the back plane insulated from the ground plate...elucidate the defeat mechanisms. In one possible EM armor design, an outer hull would serve as the electrical ground plate, while an inner, insulated...the run, the relay is closed, placing the dump resistor directly across the hot plate and ground . 2.4 Current Measurements Techniques. The circuit

  1. Composite treatment of ceramic tile armor

    DOEpatents

    Hansen, James G. R. [Oak Ridge, TN; Frame, Barbara J [Oak Ridge, TN

    2010-12-14

    An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

  2. Composite treatment of ceramic tile armor

    DOEpatents

    Hansen, James G. R. [Oak Ridge, TN; Frame, Barbara J [Oak Ridge, TN

    2012-01-02

    An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

  3. A Crashworthy Armored Pilot Seat for Helicopters

    DTIC Science & Technology

    1974-01-18

    Configuration 14 III Resoons, of F/A &Mmbars 17 IV Summay of Drop Tests 29 V Summary of Horizontal Sled Test 32 VI AcmY Armored E/A Cram=n Swot , Test Results...and 3. !st Conditions: 3 hours of vibration, resonance search, dwell and cycling in each of three (3) axes, 5 to 500 Hz maxi - mum of +2.5 g. ;sults: No

  4. Armored Combat Vehicles Science and Technology Plan

    DTIC Science & Technology

    1982-11-01

    analysis0 SS 94 GHz TRANSMITTER/RECEIVER MODULE Provide low cost transciever modules for pulsed, FMCW or FSK radars at 35-100 Gfz. STAC!LTZATTOU...prepared by TACOM. 3 !. ... Ill11111iilIl 0 1 lPI IPIt’IlA BEST AVAILABLE.COPY The Armored Combat Vehicle Science and Technology Base Development program...classes of Army Systems including Radar , E-O, AD. Communications, Missiles and EW. NETWORK MANAGEMENT INTEGRATION - BATTLEFIELD INFORMATION

  5. Improved High Strength Armor Steel through Texturing

    DTIC Science & Technology

    1979-09-01

    80 I 14 02w INTRODUCTION During metal manufacturing processing, such as rolling of sheet and plate, the polycrystalline aggregate of the material...of the quenched martensite has been documented by previous investigators including Kula and Dhosi who ob- served that thermomechanical processing can...textured armor steel exhibits improved ballistic resistance to conventionally uncontrolled rolled steels of equal hardness at normal obliquity. This

  6. Armoring confined bubbles in concentrated colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Yu, Yingxian; Khodaparast, Sepideh; Stone, Howard

    2016-11-01

    Encapsulation of a bubble with microparticles is known to significantly improve the stability of the bubble. This phenomenon has recently gained increasing attention due to its application in a variety of technologies such as foam stabilization, drug encapsulation and colloidosomes. Nevertheless, the production of such colloidal armored bubble with controlled size and particle coverage ratio is still a great challenge industrially. We study the coating process of a long air bubble by microparticles in a circular tube filled with a concentrated microparticles colloidal suspension. As the bubble proceeds in the suspension of particles, a monolayer of micro-particles forms on the interface of the bubble, which eventually results in a fully armored bubble. We investigate the phenomenon that triggers and controls the evolution of the particle accumulation on the bubble interface. Moreover, we examine the effects of the mean flow velocity, the size of the colloids and concentration of the suspension on the dynamics of the armored bubble. The results of this study can potentially be applied to production of particle-encapsulated bubbles, surface-cleaning techniques, and gas-assisted injection molding.

  7. Crystal structure of a c-di-AMP riboswitch reveals an internally pseudo-dimeric RNA

    PubMed Central

    Jones, Christopher P; Ferré-D'Amaré, Adrian R

    2014-01-01

    Cyclic diadenosine monophosphate (c-di-AMP) is a second messenger that is essential for growth and homeostasis in bacteria. A recently discovered c-di-AMP-responsive riboswitch controls the expression of genes in a variety of bacteria, including important pathogens. To elucidate the molecular basis for specific binding of c-di-AMP by a gene-regulatory mRNA domain, we have determined the co-crystal structure of this riboswitch. Unexpectedly, the structure reveals an internally pseudo-symmetric RNA in which two similar three-helix-junction elements associate head-to-tail, creating a trough that cradles two c-di-AMP molecules making quasi-equivalent contacts with the riboswitch. The riboswitch selectively binds c-di-AMP and discriminates exquisitely against other cyclic dinucleotides, such as c-di-GMP and cyclic-AMP-GMP, via interactions with both the backbone and bases of its cognate second messenger. Small-angle X-ray scattering experiments indicate that global folding of the riboswitch is induced by the two bound cyclic dinucleotides, which bridge the two symmetric three-helix domains. This structural reorganization likely couples c-di-AMP binding to gene expression. PMID:25271255

  8. Future Armor Tiles MIL-STD-166O Tests.

    DTIC Science & Technology

    1997-02-01

    The U.S. Army Defense Ammunition Center (DAC), Validation Engineering Division, was tasked by DAC to conduct MIL- STD -1660 tests on armor tile...containers on a wooden pallet. This report contains test results with the armor tile containers on a wooden pallet meeting MIL- STD -1660, Design Criteria for Ammunition Unit Loads, requirements.

  9. 75 FR 25208 - Announcement of Body Armor Research Needs Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ...-day High Strength Fiber and Body Armor Research Needs Meeting. The Meeting will provide a forum to... the examination of such issues as material longevity, new materials, and improved testing.... Presentations on today's challenges in body armor and material longevity research will be given. Among...

  10. Translation of encephalomyocarditis virus RNA: parameters influencing the selection of the internal initiation site.

    PubMed Central

    Kaminski, A; Belsham, G J; Jackson, R J

    1994-01-01

    The initiation of encephalomyocarditis virus RNA translation is by internal ribosome entry almost exclusively at the 11th AUG codon from the 5'-end, which is the central of the three AUG codons in the sequence..[sequence: see text].., and is located some 25 nt downstream from an oligopyrimidine tract conserved amongst related viruses. As the sequences between the oligopyrimidine tract and AUG-10/11 are poorly conserved and thus possibly serve only as a spacer, the influence of this spacer length on initiation frequency at the three AUG codons was examined in vitro and in vivo. Deletion of 11 residues resulted in initiation almost exclusively at AUG-12 but at significantly reduced overall efficiency. Insertion of eight residues caused a 15-fold increase in initiation frequency at AUG-10 and a decrease at AUG-11. Longer insertions reduced overall efficiency without changing the initiation site preferences. With the wild-type spacing, complete substitution of the oligopyrimidine tract by purines caused a 30-35% decrease in initiation efficiency, and partial substitution only a 10-15% decrease. Thus the internal initiation mechanism selects the initiation site partly on the basis of its distance from upstream elements, of which the oligopyrimidine tract is not the most critical, but for reasons not yet understood a preference for AUG-11 is superimposed on this selection. Images PMID:8157006

  11. Optimal Hydrophobicity in Ring-Opening Metathesis Polymerization-Based Protein Mimics Required for siRNA Internalization.

    PubMed

    deRonde, Brittany M; Posey, Nicholas D; Otter, Ronja; Caffrey, Leah M; Minter, Lisa M; Tew, Gregory N

    2016-06-13

    Exploring the role of polymer structure for the internalization of biologically relevant cargo, specifically siRNA, is of critical importance to the development of improved delivery reagents. Herein, we report guanidinium-rich protein transduction domain mimics (PTDMs) based on a ring-opening metathesis polymerization scaffold containing tunable hydrophobic moieties that promote siRNA internalization. Structure-activity relationships using Jurkat T cells and HeLa cells were explored to determine how the length of the hydrophobic block and the hydrophobic side chain compositions of these PTDMs impacted siRNA internalization. To explore the hydrophobic block length, two different series of diblock copolymers were synthesized: one series with symmetric block lengths and one with asymmetric block lengths. At similar cationic block lengths, asymmetric and symmetric PTDMs promoted siRNA internalization in the same percentages of the cell population regardless of the hydrophobic block length; however, with 20 repeat units of cationic charge, the asymmetric block length had greater siRNA internalization, highlighting the nontrivial relationships between hydrophobicity and overall cationic charge. To further probe how the hydrophobic side chains impacted siRNA internalization, an additional series of asymmetric PTDMs was synthesized that featured a fixed hydrophobic block length of five repeat units that contained either dimethyl (dMe), methyl phenyl (MePh), or diphenyl (dPh) side chains and varied cationic block lengths. This series was further expanded to incorporate hydrophobic blocks consisting of diethyl (dEt), diisobutyl (diBu), and dicyclohexyl (dCy) based repeat units to better define the hydrophobic window for which our PTDMs had optimal activity. High-performance liquid chromatography retention times quantified the relative hydrophobicities of the noncationic building blocks. PTDMs containing the MePh, diBu, and dPh hydrophobic blocks were shown to have superior

  12. Research Investigation of Armor Plate Steels

    DTIC Science & Technology

    1942-02-20

    location at which the ballistic limits were determined. Ballistic limits and average hardness values from the 16 duplicate plates are given in Table 10 ...OF ARMOR PLATE STEELS Plate Nuzuber %C %.Mn %Si %Ni. %Cr %Mo %cu *7111 .46 1.58 .20 . 10 /.20 7276 .50 1.07 .3o 7277 .39 .35 .23 7278 .47 .91 .26 7279...26 2.3/2.7 7328 .34 .89 .20 1.3/1.7 .35/.46 * 7329 .34 .88 .25 1.3/1.7 10 /.20 7330 .46 .86 .24 .25/.35 : 10 /.20 734 .46 .84 .29 W 5. 35 7341 .34 .94

  13. Shaft mines can get power without armor

    SciTech Connect

    Brezovec, D.

    1984-02-01

    A Pennsylvania coal operator has been able to install neoprene jacketed mine power feeder (MPF) cable in an airshaft without the use of expensive armored power cables. Armored cables traditionally have been favored in applications where the cable is dropped vertically because their galvanized metal shielding protects the cable as it is dragged across rough ground and stretched by its own weight as it is lowered into the hole. But armored cable poses some problems. It is as much as $20 per foot more expensive than MPF cable. Also, sinking armored cables is particularly difficult when space is limited because the cable must be laid out on the ground before it is lowered into the hole. The technique that allowed Pennsylvania Mines Corp. to install two 750-ft-long, 15-kv cables at is 400,000-tpy Tunnelton mine, near New Alexandria, Pa., was devised by J.H. Service Co.'s Indianola, Pa., branch office. The method involves feeding MPF cable from a spool on a truck equipped with special braking devices, over a steel drum that acts as a sheave, directly into a mine shaft or borehole. Robert C. Kadyk, a sales manager with J.H. Service, says that while this is not the first time standard MPF cable has been used in a borehole or shaft, the cables are not usually used in these cases because there were no dependable methods for holding the cable steady as it was lowered into the hole to keep it from abrading against the sides of the borehole or shaft. Also, dragging MPF cable through the woods invariably damages it. With its cable sinking method, J.H. Service vulcanizes stainless steel kellems grips into the cable about every 100 ft. The interval varies with the weight and diameter of the cable, depth of the hole, and length of the kellems grip. One twisted steel messenger wire is attached to each kellems grip to displace the weight of the cable as it takes its trip to the mine floor.

  14. Peptide Mapping of Aminoacyl-tRNA Synthetases: Evidence for Internal Sequence Homology in Escherichia coli Leucyl-tRNA Synthetase

    PubMed Central

    Waterson, Robert M.; Konigsberg, William H.

    1974-01-01

    Most aminoacyl-tRNA synthetases contain polypeptide chains of about either 50,000 or 100,000 daltons. Peptide mapping of tryptic, chymotryptic, or Staphylococcus aureus acid protease digests of seryl-tRNA synthetase (100,000, dimer) and leucyl-tRNA synthetase (100,000, monomer) from E. coli was done after selective modification of lysine residues with [14C]succinic anhydride or of methionine residues with [14C]iodoacetate. By use of thin-layer electrophoresis and chromatography on silicagel or cellulose plates followed by radioautography it was possible, depending upon the specific activity of the reagent used, to detect radioactive peptides obtained from as little as l μg of protein. Seryl-tRNA synthetase gave the correct number of tryptic peptides expected for a dimer of identical subunits. Leucyl-tRNA synthetase, on the other hand, gave roughly half the number of radioactive tryptic, chymotryptic, and acid protease peptides expected from the lysine, arginine, and methionine content of the 100,000 monomer. We have interpreted these results as indicating that extensive internal homology exists among lysine- and methionine-containing peptides within the leucyl-tRNA synthetase. The simplest conclusion that can be drawn from these observations is that the NH2- and COOH-terminal halves of leucyl-tRNA synthetase and perhaps other synthetases of 100,000 molecular weight may have evolved through a process of gene duplication and fusion, followed by limited diversification by way of amino-acid substitutions accumulating during evolution. Images PMID:4592690

  15. Site-specific labeling of RNA at internal ribose hydroxyl groups: terbium-assisted deoxyribozymes at work.

    PubMed

    Büttner, Lea; Javadi-Zarnaghi, Fatemeh; Höbartner, Claudia

    2014-06-04

    A general and efficient single-step method was established for site-specific post-transcriptional labeling of RNA. Using Tb(3+) as accelerating cofactor for deoxyribozymes, various labeled guanosines were site-specifically attached to 2'-OH groups of internal adenosines in in vitro transcribed RNA. The DNA-catalyzed 2',5'-phosphodiester bond formation proceeded efficiently with fluorescent, spin-labeled, biotinylated, or cross-linker-modified guanosine triphosphates. The sequence context of the labeling site was systematically analyzed by mutating the nucleotides flanking the targeted adenosine. Labeling of adenosines in a purine-rich environment showed the fastest reactions and highest yields. Overall, practically useful yields >70% were obtained for 13 out of 16 possible nucleotide (nt) combinations. Using this approach, we demonstrate preparative labeling under mild conditions for up to ~160-nt-long RNAs, including spliceosomal U6 small nuclear RNA and a cyclic-di-AMP binding riboswitch RNA.

  16. Character shifts in the defensive armor of sympatric sticklebacks.

    PubMed

    Vamosi, Steven M; Schluter, Dolph

    2004-02-01

    Natural enemies may contribute to the morphological divergence of sympatric species, yet their role has received little attention to date. We tested for character shifts in defensive armor of sympatric threespine sticklebacks (Gasterosteus aculeatus complex) previously shown to exhibit ecological character displacement in traits related to resource use. We scored five defensive armor traits in sympatric benthic and limnetic stickleback species from southwestern British Columbia and compared them with the same traits in nearby allopatric populations in the presence of the same predatory fish (Oncorhynchus sp.). This approach is analogous to tests of ecological character displacement that compare trophic traits of sympatric and allopatric species in the presence of the same community of resource types. Three patterns consistent with character displacement in defensive armor were found. First, limnetics in different lakes had consistently more armor than sympatric benthics. Second, the average amount of armor, averaged over both species, was reduced in sympatry compared to allopatric populations. This reduction was almost entirely the result of shifts by benthic species, whereas armor in limnetics was more similar to that in allopatric populations. Third, differences between sympatric benthics and limnetics in total armor were greater than expected from comparisons with allopatric populations. We interpret these patterns as the result of differences in habitat-specific predation regimes accompanying ecological character displacement and indirect interactions between sympatric stickleback species mediated by their top predators. These results suggest that predation may facilitate, rather than hinder, the process of divergence in sympatry.

  17. Internal translation initiation from HIV-1 transcripts is conferred by a common RNA structure.

    PubMed

    Plank, Terra-Dawn M; Whitehurst, James T; Cencic, Regina; Pelletier, Jerry; Kieft, Jeffrey S

    2014-01-01

    Alternative splicing of the human immunodeficiency virus 1 (HIV-1) RNA transcripts produces mRNAs encoding nine different viral proteins. The leader of each contains a common non-coding exon at the 5' end. Previous studies showed that the leaders from the common exon-containing transcripts gag, nef, vif, vpr and vpu can direct protein synthesis through internal ribosome entry sites (IRESs) with varying efficiencies. Here we explored whether the common exon acts as an IRES element in the context of all the 5' leaders or if each harbors a distinct IRES. We also explored the relationship between the IRESs and initiation codon selection. We find that the common exon adopts a similar conformation in every leader we explored and that the sequence and structure is required for IRES activity. We also find that each leader uses a scanning mechanism for start codon identification. Together, our data point to a model in which the common exon on HIV-1 transcripts acts as the ribosome landing pad, recruiting preinitiation complexes upstream of the initiation codon, followed by scanning to each transcript's initiator AUG.

  18. Internal translation initiation from HIV-1 transcripts is conferred by a common RNA structure

    PubMed Central

    Plank, Terra-Dawn M; Whitehurst, James T; Cencic, Regina; Pelletier, Jerry; Kieft, Jeffrey S

    2014-01-01

    Alternative splicing of the human immunodeficiency virus 1 (HIV-1) RNA transcripts produces mRNAs encoding nine different viral proteins. The leader of each contains a common non-coding exon at the 5' end. Previous studies showed that the leaders from the common exon-containing transcripts gag, nef, vif, vpr and vpu can direct protein synthesis through internal ribosome entry sites (IRESs) with varying efficiencies. Here we explored whether the common exon acts as an IRES element in the context of all the 5' leaders or if each harbors a distinct IRES. We also explored the relationship between the IRESs and initiation codon selection. We find that the common exon adopts a similar conformation in every leader we explored and that the sequence and structure is required for IRES activity. We also find that each leader uses a scanning mechanism for start codon identification. Together, our data point to a model in which the common exon on HIV-1 transcripts acts as the ribosome landing pad, recruiting preinitiation complexes upstream of the initiation codon, followed by scanning to each transcript's initiator AUG. PMID:26779399

  19. An international comparability study on quantification of mRNA gene expression ratios: CCQM-P103.1.

    PubMed

    Devonshire, Alison S; Sanders, Rebecca; Whale, Alexandra S; Nixon, Gavin J; Cowen, Simon; Ellison, Stephen L R; Parkes, Helen; Pine, P Scott; Salit, Marc; McDaniel, Jennifer; Munro, Sarah; Lund, Steve; Matsukura, Satoko; Sekiguchi, Yuji; Kawaharasaki, Mamoru; Granjeiro, José Mauro; Falagan-Lotsch, Priscila; Saraiva, Antonio Marcos; Couto, Paulo; Yang, Inchul; Kwon, Hyerim; Park, Sang-Ryoul; Demšar, Tina; Žel, Jana; Blejec, Andrej; Milavec, Mojca; Dong, Lianhua; Zhang, Ling; Sui, Zhiwei; Wang, Jing; Viroonudomphol, Duangkamol; Prawettongsopon, Chaiwat; Partis, Lina; Baoutina, Anna; Emslie, Kerry; Takatsu, Akiko; Akyurek, Sema; Akgoz, Muslum; Vonsky, Maxim; Konopelko, L A; Cundapi, Edna Matus; Urquiza, Melina Pérez; Huggett, Jim F; Foy, Carole A

    2016-06-01

    Measurement of RNA can be used to study and monitor a range of infectious and non-communicable diseases, with profiling of multiple gene expression mRNA transcripts being increasingly applied to cancer stratification and prognosis. An international comparison study (Consultative Committee for Amount of Substance (CCQM)-P103.1) was performed in order to evaluate the comparability of measurements of RNA copy number ratio for multiple gene targets between two samples. Six exogenous synthetic targets comprising of External RNA Control Consortium (ERCC) standards were measured alongside transcripts for three endogenous gene targets present in the background of human cell line RNA. The study was carried out under the auspices of the Nucleic Acids (formerly Bioanalysis) Working Group of the CCQM. It was coordinated by LGC (United Kingdom) with the support of National Institute of Standards and Technology (USA) and results were submitted from thirteen National Metrology Institutes and Designated Institutes. The majority of laboratories performed RNA measurements using RT-qPCR, with datasets also being submitted by two laboratories based on reverse transcription digital polymerase chain reaction and one laboratory using a next-generation sequencing method. In RT-qPCR analysis, the RNA copy number ratios between the two samples were quantified using either a standard curve or a relative quantification approach. In general, good agreement was observed between the reported results of ERCC RNA copy number ratio measurements. Measurements of the RNA copy number ratios for endogenous genes between the two samples were also consistent between the majority of laboratories. Some differences in the reported values and confidence intervals ('measurement uncertainties') were noted which may be attributable to choice of measurement method or quantification approach. This highlights the need for standardised practices for the calculation of fold change ratios and uncertainties in the

  20. Internal initiation of translation directed by the 5'-untranslated region of the tobamovirus subgenomic RNA I(2).

    PubMed

    Skulachev, M V; Ivanov, P A; Karpova, O V; Korpela, T; Rodionova, N P; Dorokhov, Y L; Atabekov, J G

    1999-10-10

    Previously we reported that, unlike RNA of typical tobamoviruses, the translation of the coat protein (CP) gene of a crucifer-infecting tobamovirus (crTMV) in vitro occurred by an internal ribosome entry mechanism mediated by the 148-nt region that contained an internal ribosome entry site (IRES(CP,148)(CR)). The equivalent 148-nt sequence from TMV U1 RNA (U1(CP,148)(SP)) was incapable of promoting internal initiation. In the present work, we have found that the 228-nt region upstream of the movement protein (MP) gene of crTMV RNA (IRES(MP,228)(CR)) contained an IRES element that directed in vitro translation of the 3'-proximal reporter genes from chimeric dicistronic transcripts. Surprisingly, the equivalent 228-nt sequence upstream from the MP gene of TMV U1 directed translation of the downstream gene of a dicistronic transcripts as well. Consequently this sequence was termed IRES(MP,228)(U1). It was shown that IRES(MP,228)(CR), IRES(MP,228)(U1), and IRES(CP,148)(CR) could mediate expression of the 3'-proximal GUS gene from dicistronic 35S promoter-based constructs in vivo in experiments on transfection of tobacco protoplasts and particle bombardment of Nicotiana benthamiana leaves. The results indicated that an IRES element was located within the 75-nt region upstream of MP gene (IRES(MP,75)), which corresponded closely to the length of the 5'UTR of TMV subgenomic RNA (sgRNA) I(2). The RNA transcripts structurally equivalent to I(2) sgRNAs of TMV U1 and crTMV, but containing a hairpin structure (H) immediately upstream of IRES(MP,75) (HIRES(MP), (75)(CR)-MP-CP-3'UTR; HIRES(MP,75)(U1)-MP-CP-3'UTR), were able to express the MP gene in vitro. The capacity of HIRES(MP,75)(CR) sequence for mediating internal translation of the 3'-proximal GUS gene in vivo, in tobacco protoplasts, was demonstrated. We suggested that expression of the MP gene from I(2) sgRNAs might proceed via internal ribosome entry pathway mediated by IRES(MP) element contained in the 75-nt 5'UTR

  1. Requirement of rRNA Methylation for 80S Ribosome Assembly on a Cohort of Cellular Internal Ribosome Entry Sites▿

    PubMed Central

    Basu, Abhijit; Das, Priyanka; Chaudhuri, Sujan; Bevilacqua, Elena; Andrews, Joel; Barik, Sailen; Hatzoglou, Maria; Komar, Anton A.; Mazumder, Barsanjit

    2011-01-01

    Protein syntheses mediated by cellular and viral internal ribosome entry sites (IRESs) are believed to have many features in common. Distinct mechanisms for ribosome recruitment and preinitiation complex assembly between the two processes have not been identified thus far. Here we show that the methylation status of rRNA differentially influenced the mechanism of 80S complex formation on IRES elements from the cellular sodium-coupled neutral amino acid transporter 2 (SNAT2) versus the hepatitis C virus mRNA. Translation initiation involves the assembly of the 48S preinitiation complex, followed by joining of the 60S ribosomal subunit and formation of the 80S complex. Abrogation of rRNA methylation did not affect the 48S complex but resulted in impairment of 80S complex assembly on the cellular, but not the viral, IRESs tested. Impairment of 80S complex assembly on the amino acid transporter SNAT2 IRES was rescued by purified 60S subunits containing fully methylated rRNA. We found that rRNA methylation did not affect the activity of any of the viral IRESs tested but affected the activity of numerous cellular IRESs. This work reveals a novel mechanism operating on a cohort of cellular IRESs that involves rRNA methylation for proper 80S complex assembly and efficient translation initiation. PMID:21930789

  2. Design of armor for protection against blast and impact

    NASA Astrophysics Data System (ADS)

    Rahimzadeh, Tanaz; Arruda, Ellen M.; Thouless, M. D.

    2015-12-01

    The features of blast and impact that can damage a delicate target supported by a structure include both the peak pressure and the impulse delivered to the structure. This study examines how layers of elastic and visco-elastic materials may be assembled to mitigate these features. The impedance mismatch between two elastic layers is known to reduce the pressure, but dissipation is required to mitigate the transmitted impulse in light-weight armor. A novel design concept called impact or blast tuning is introduced in which a multi-layered armor is used to tune the stress waves resulting from an impact or blast to specific frequencies that match the damping frequencies of visco-elastic layers. The material and geometrical parameters controlling the viscous dissipation of the energy within the armor are identified for a simplified one-dimensional system, to provide insight into how the optimal design of multi-use armor might be based on this concept.

  3. OPTIMIZING TRANSPARENT ARMOR DESIGN SUBJECT TO PROJECTILE IMPACT CONDITIONS

    SciTech Connect

    Sun, Xin; Lai, Canhai; Gorsich, Tara; Templeton, Douglas W.

    2009-03-01

    Design and manufacturing of transparent armor have been historically carried out using experimental approaches. In this study, we use advanced computational modeling tools to perform virtual design evaluations of transparent armor systems under different projectile impact conditions. AHPCRC developed modeling software EPIC’06 [1] is used in predicting the penetration resistance of transparent armor systems. LaGrangian-based finite element analyses combined with particle dynamics are used to simulate the damage initiation and propagation process for the armor system under impact conditions. It is found that a 1-parameter single state model can be used to predict the impact penetration depth with relatively good accuracy, suggesting that the finely comminuted glass particles follow the behavior similar to a viscous fluid. Even though the intact strength of borosilicate and soda lime glass are different, the same fractured strength can be used for both glasses to capture the penetration depth.

  4. Armor systems including coated core materials

    DOEpatents

    Chu, Henry S [Idaho Falls, ID; Lillo, Thomas M [Idaho Falls, ID; McHugh, Kevin M [Idaho Falls, ID

    2012-07-31

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  5. Armor systems including coated core materials

    SciTech Connect

    Chu, Henry S; Lillo, Thomas M; McHugh, Kevin M

    2013-10-08

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  6. Human Factors Assessment: M9 Armored Combat Earthmover (ACE)

    DTIC Science & Technology

    1988-04-01

    Occasionally, M9s over- heated during continued road marches with armor units. Additional radiator water was needed. Food During the FTX the M9s...traveled with armored units and ahead of engineer support units. Operators were not supplied with hot or cold food . Five gal. cans of hydraulic During...brake on the winch. 2. The winch had to be inoving in order to shift gears. 3. The winch capacity is only 30,000 lbs, while the vehicle weighs

  7. Penetration Resistance of Armor Ceramics: Dimensional Analysis and Property Correlations

    DTIC Science & Technology

    2015-08-01

    validation experiments can be organized and compared. 15. SUBJECT TERMS ceramics, terminal ballistics, armor, dimensional analysis 16. SECURITY... Terminal ballistics Armor Dimensional analysis* Impact Physics RDRL-WMP-C, US Army Research L Ground, MD 21005-5066, USA. Tel.: þ1 410 278 6146 E-mail...shock properties of ce- ramics. Adv Appl Ceram 2010;109:446e66. [2] Rosenberg Z, Dekel E. Terminal ballistics. Berlin: Springer; 2012. [3] Kaufmann C

  8. High-Resolution Differentiation of Cyanobacteria by Using rRNA-Internal Transcribed Spacer Denaturing Gradient Gel Electrophoresis

    PubMed Central

    Janse, Ingmar; Meima, Marion; Kardinaal, W. Edwin A.; Zwart, Gabriel

    2003-01-01

    For many ecological studies of cyanobacteria, it is essential that closely related species or strains can be discriminated. Since this is often not possible by using morphological features, cyanobacteria are frequently studied by using DNA-based methods. A powerful method for analysis of the diversity and dynamics of microbial populations and for checking the purity and affiliation of cultivated strains is denaturing gradient gel electrophoresis (DGGE). We realized high-resolution discrimination of a variety of cyanobacteria by means of DGGE analysis of sections of the internal transcribed spacer between the 16S and 23S rRNA genes (rRNA-ITS). A forward primer specific for cyanobacteria, targeted at the 3′ end of the 16S rRNA gene, was designed. The combination of this primer and three different reverse primers targeted to the rRNA-ITS or to the 23S rRNA gene yielded PCR products of different sizes from cultures of all 16 cyanobacterial genera that were tested but not from other bacteria. DGGE profiles produced from the shortest section of rRNA-ITS consisted of one band for all but one cyanobacterial genera, and those generated from longer stretches of rRNA-ITS yielded DGGE profiles containing one to four bands. The suitability of DGGE for detecting intrageneric and intraspecific variation was tested by using strains of the genus Microcystis. Many strains could be discriminated by means of rRNA-ITS DGGE, and the resolution of this method was strikingly higher than that obtained with previously described methods. The applicability of the developed DGGE assays for analysis of cyanobacteria in field samples was demonstrated by using samples from freshwater lakes. The advantages and disadvantages associated with the use of each developed primer set are discussed. PMID:14602623

  9. Myotonic Dystrophy Type 1 RNA Crystal Structures Reveal Heterogeneous 1×1 Nucleotide UU Internal Loop Conformations⊥

    PubMed Central

    Kumar, Amit; Park, HaJeung; Fang, Pengfei; Parkesh, Raman; Guo, Min; Nettles, Kendall W.; Disney, Matthew D.

    2011-01-01

    RNA internal loops often display a variety of conformations in solution. Herein, we visualize conformational heterogeneity in the context of the 5′CUG/3′GUC repeat motif present in the RNA that causes myotonic dystrophy type 1 (DM1). Specifically, two crystal structures are disclosed of a model DM1 triplet repeating construct, 5′r(UUGGGC(CUG)3GUCC)2, refined to 2.20 Å and 1.52 Å resolution. Here, differences in orientation of the 5′ dangling UU end between the two structures induce changes in the backbone groove width, which reveals that non-canonical 1×1 nucleotide UU internal loops can display an ensemble of pairing conformations. In the 2.20 Å structure, CUGa, the 5′UU forms one hydrogen-bonded pairs with a 5′UU of a neighboring helix in the unit cell to form a pseudo-infinite helix. The central 1×1 nucleotide UU internal loop has no hydrogen bonds, while the terminal 1×1 nucleotide UU internal loops each form a one hydrogen-bonded pair. In the 1.52 Å structure, CUGb, the 5′ UU dangling end is tucked into the major groove of the duplex. While the canonical paired bases show no change in base pairing, in CUGb the terminal 1×1 nucleotide UU internal loops form now two hydrogen-bonded pairs. Thus, the shift in major groove induced by the 5′UU dangling end alters non-canonical base patterns. Collectively, these structures indicate that 1×1 nucleotide UU internal loops in DM1 may sample multiple conformations in vivo. This observation has implications for the recognition of this RNA, and other repeating transcripts, by protein and small molecule ligands. PMID:21988728

  10. Myotonic dystrophy type 1 RNA crystal structures reveal heterogeneous 1 × 1 nucleotide UU internal loop conformations.

    PubMed

    Kumar, Amit; Park, HaJeung; Fang, Pengfei; Parkesh, Raman; Guo, Min; Nettles, Kendall W; Disney, Matthew D

    2011-11-15

    RNA internal loops often display a variety of conformations in solution. Herein, we visualize conformational heterogeneity in the context of the 5'CUG/3'GUC repeat motif present in the RNA that causes myotonic dystrophy type 1 (DM1). Specifically, two crystal structures of a model DM1 triplet repeating construct, 5'r[UUGGGC(CUG)(3)GUCC](2), refined to 2.20 and 1.52 Å resolution are disclosed. Here, differences in the orientation of the 5' dangling UU end between the two structures induce changes in the backbone groove width, which reveals that noncanonical 1 × 1 nucleotide UU internal loops can display an ensemble of pairing conformations. In the 2.20 Å structure, CUGa, the 5' UU forms a one hydrogen-bonded pair with a 5' UU of a neighboring helix in the unit cell to form a pseudoinfinite helix. The central 1 × 1 nucleotide UU internal loop has no hydrogen bonds, while the terminal 1 × 1 nucleotide UU internal loops each form a one-hydrogen bond pair. In the 1.52 Å structure, CUGb, the 5' UU dangling end is tucked into the major groove of the duplex. While the canonically paired bases show no change in base pairing, in CUGb the terminal 1 × 1 nucleotide UU internal loops now form two hydrogen-bonded pairs. Thus, the shift in the major groove induced by the 5' UU dangling end alters noncanonical base patterns. Collectively, these structures indicate that 1 × 1 nucleotide UU internal loops in DM1 may sample multiple conformations in vivo. This observation has implications for the recognition of this RNA, and other repeating transcripts, by protein and small molecule ligands.

  11. Defensive aids suite prototype for light armored vehicles

    NASA Astrophysics Data System (ADS)

    Cantin, Andre; Fortin, Jean; Venter, Johan; Philip, Brian G.; Hagen, Russell; Krieger, Dietmar; Greenley, Mike

    2001-09-01

    The Defence Research Establishment Valcartier has initiated in 1998 R&D work to investigate and to demonstrate key technologies required for future Defensive Aid Suite to protect Light Armoured Vehicles. A basic Defensive Aid Suite demonstrator (Phase I) was built and integrated into the LAV vetronics by Litton Systems Canada and his consortium. The Defensive Aid Suite consisted of a 2-band HARLIDTM-based laser detection head, a processor capable to control and deploy countermeasures and a DAS touch-screen display all integrated in a Light Armored Vehicle. The crew was able to select the operation mode for direct fire or smoke deployment by pushing one of the pair of buttons available at the bottom of the display. This system was successfully demonstrated in October 1999 during an international trial. This article gives an overview of the results obtained in the field as well as some of the lessons learnt. It also describes laboratory and field measurements made on the Laser Warning Receiver unit itself. The results of the DAS tactical use and of Human factor evaluation will illustrate its performance within typical laser threat scenarios. This work will serve as the basis for the recommendation of a future DAS demonstrator (Phase II) integrating more sensors and countermeasures.

  12. Effect of Liposome Size on Internal RNA Replication Coupled with Replicase Translation.

    PubMed

    Sunami, Takeshi; Ichihashi, Norikazu; Nishikawa, Takehiro; Kazuta, Yasuaki; Yomo, Tetsuya

    2016-07-01

    Cell membranes inhibit the diffusion of intracellular materials, and compartment size can strongly affect the intracellular biochemical reactions. To assess the effect of the size of microcompartments on intracellular reactions, we constructed a primitive cell model consisting of giant liposomes and a translation-coupled RNA replication (TcRR) system. The RNA was replicated by Qβ replicase, which was translated from the RNA in giant liposomes encapsulating the cell-free translation system. A reporter RNA encoding the antisense strand of β-glucuronidase was introduced into the system to yield a TcRR read-out (green fluorescence). We demonstrate that TcRR was hardly detectable in larger liposomes (230 fL) but was more effective in smaller (7.7 fL) liposomes. Our experimental and theoretical results show that smaller microcompartments considerably enhance TcRR because the synthesized molecules, such as RNA and replicases, are more concentrated in smaller liposomes.

  13. Global shape mimicry of tRNA within a viral internal ribosome entry site mediates translational reading frame selection

    PubMed Central

    Au, Hilda H.; Cornilescu, Gabriel; Mouzakis, Kathryn D.; Ren, Qian; Burke, Jordan E.; Lee, Seonghoon; Butcher, Samuel E.; Jan, Eric

    2015-01-01

    The dicistrovirus intergenic region internal ribosome entry site (IRES) adopts a triple-pseudoknotted RNA structure and occupies the core ribosomal E, P, and A sites to directly recruit the ribosome and initiate translation at a non-AUG codon. A subset of dicistrovirus IRESs directs translation in the 0 and +1 frames to produce the viral structural proteins and a +1 overlapping open reading frame called ORFx, respectively. Here we show that specific mutations of two unpaired adenosines located at the core of the three-helical junction of the honey bee dicistrovirus Israeli acute paralysis virus (IAPV) IRES PKI domain can uncouple 0 and +1 frame translation, suggesting that the structure adopts distinct conformations that contribute to 0 or +1 frame translation. Using a reconstituted translation system, we show that ribosomes assembled on mutant IRESs that direct exclusive 0 or +1 frame translation lack reading frame fidelity. Finally, a nuclear magnetic resonance/small-angle X-ray scattering hybrid approach reveals that the PKI domain of the IAPV IRES adopts an RNA structure that resembles a complete tRNA. The tRNA shape-mimicry enables the viral IRES to gain access to the ribosome tRNA-binding sites and form intermolecular contacts with the ribosome that are necessary for initiating IRES translation in a specific reading frame. PMID:26554019

  14. Molecular recognition of 6'-N-5-hexynoate kanamycin A and RNA 1x1 internal loops containing CA mismatches.

    PubMed

    Tran, Tuan; Disney, Matthew D

    2011-02-15

    In our previous study to identify the RNA internal loops that bind an aminoglycoside derivative, we determined that 6'-N-5-hexynoate kanamycin A prefers to bind 1x1 nucleotide internal loops containing C·A mismatches. In this present study, the molecular recognition between a variety of RNAs that are mutated around the C·A loop and the ligand was investigated. Studies show that both loop nucleotides and loop closing pairs affect binding affinity. Most interestingly, it was shown that there is a correlation between the thermodynamic stability of the C·A internal loops and ligand affinity. Specifically, C·A loops that had relatively high or low stability bound the ligand most weakly whereas loops with intermediate stability bound the ligand most tightly. In contrast, there is no correlation between the likelihood that a loop forms a C-A(+) pair at lower pH and ligand affinity. It was also found that a 1x1 nucleotide C·A loop that bound to the ligand with the highest affinity is identical to the consensus site in RNAs that are edited by adenosine deaminases acting on RNA type 2 (ADAR2). These studies provide a detailed investigation of factors affecting small molecule recognition of internal loops containing C·A mismatches, which are present in a variety of RNAs that cause disease.

  15. Preparing soft-bodied arthropods for arthropods for microscope examination: Armored Scales (Insects: Hemiptera: Diaspididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper identification of armored scales (Hemiptera: Diaspididae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare armored scales specimens on microscope slides for examination and identification. Steps ranging from collect...

  16. The Army’s Armored Multi-Purpose Vehicle (AMPV): Background and Issues for Congress

    DTIC Science & Technology

    2013-09-24

    purpose vehicles, mortar carriers, and medical treatment and evacuation vehicles. An estimated 3,000 of these M-113 variants are currently in...transportable, armored multi-purpose vehicle family intended to provide a lightweight , amphibious armored personnel carrier for armor and mechanized infantry...a number of different variations of the M-113 were produced to fulfill such roles as a command and control vehicle, mortar carrier, and armored

  17. In vivo analyses of the internal control region in the 5S rRNA gene from Saccharomyces cerevisiae.

    PubMed

    Lee, Y; Erkine, A M; Van Ryk, D I; Nazar, R N

    1995-02-25

    The internal control region of the Saccharomyces cerevisiae 5S rRNA gene has been characterized in vivo by genomic DNase I footprinting and by mutational analyses using base substitutions, deletions or insertions. A high copy shuttle vector was used to efficiently express mutant 5S rRNA genes in vivo and isotope labelling kinetics were used to distinguish impeded gene expression from nascent RNA degradation. In contrast to mutational studies in reconstituted systems, the analyses describe promoter elements which closely resemble the three distinct sequence elements that have been observed in Xenopus laevis 5S rRNA. The results indicate a more highly conserved structure than previously reported with reconstituted systems and suggest that the saturated conditions which are used in reconstitution studies mask sequence dependence which may be physiologically significant. Footprint analyses support the extended region of protein interaction which has recently been observed in some reconstituted systems, but mutational analyses indicate that these interactions are not sequence specific. Periodicity in the footprint provides further detail regarding the in vivo topology of the interacting protein.

  18. Nondestructive characterization of UHMWPE armor materials

    NASA Astrophysics Data System (ADS)

    Chiou, Chien-Ping; Margetan, Frank J.; Barnard, Daniel J.; Hsu, David K.; Jensen, Terrence; Eisenmann, David

    2012-05-01

    Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

  19. Nondestructive characterization of UHMWPE armor materials

    SciTech Connect

    Chiou, Chien-Ping; Margetan, Frank J.; Barnard, Daniel J.; Hsu, David K.; Jensen, Terrence; Eisenmann, David

    2012-05-17

    Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

  20. Cardiopulmonary signal sensing from subject wearing body armor.

    PubMed

    Park, Byung-Kwon; Lubecke, Victor; Boric-Lubecke, Olga; Host-Madsen, Anders

    2007-01-01

    Continuous wave (CW) Doppler motion sensing radar can detect human physiological signal such as respiration or heart signals at a distance and through barriers. It has been shown that heart rate can be extracted with good accuracy for normally clothed subjects. Such technique could potentially be used to search for survivors in battlefield triage applications. To assess the feasibility of such applications, we investigated Doppler radar of cardiopulmonary signal sensing from subjects wearing body armor vests. This paper presents measurement results of heart signals obtained using CW Doppler radar from a subject wearing body armor vest. Since armor plate reflects most of the RF signal, received signal after reflected from a subject is phase modulated with motion of an armor plate induced by chest motion, rather than directly with chest motion due to cardiopulmonary motion. Two different cases, including supine and seated positions, are chosen for this study, and good sensitivity was obtained in both cases. To the best of author's knowledge, this is the first published result of cardiopulmonary signal detection from a subject wearing a body armor vest.

  1. Large-area ALON windows for reconnaissance and armor applications

    NASA Astrophysics Data System (ADS)

    Goldman, Lee M.; Twedt, Richard; Foti, Robyn; Smith, Mark; Sastri, Suri A.

    2009-05-01

    The demand for large ALON® windows has continued to increase since the material transitioned to Surmet Corporation for commercialization. Two applications which represent opposite ends of the requirements spectrum in terms of required optical performance and cost sensitivity are Reconnaissance windows and transparent armor. Consequently, the approaches to producing large area windows for both applications are quite different. While Recce applications require windows of the highest possible optical quality and stringent refractive index homogeneity across the large aperture sizes of Recce sensors, the optical requirements for transparent armor windows are substantially looser. Furthermore, optical performance is paramount for Recce applications while transparent armor applications are more strongly driven by cost considerations. Surmet has developed processes for producing large (i.e., up to ~17x30-in) ALON® window blanks of extremely high optical quality and refractive index homogeneity, for Recce applications. This material has been optically fabricated into finished windows and characterized for transmitted wavefront and homogeneity. Recent results will be presented. Large area transparent armor windows have been produced using a tiling approach. Since transparent armor laminates consist of multiple layers (i.e., ALON/Glass/Polycarbonate) Smaller ALON® tiles can be face bonded onto the underlying glass and polycarbonate layers to produce very large windows. Excellent ballistic results have been obtained using a tiled configuration. Recent results will be presented.

  2. Toroidal midplane neutral beam armor and plasma limiter

    DOEpatents

    Kugel, Henry W.; Hand Jr, Samuel W.; Ksayian, Haig

    1986-02-04

    For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil. The upper and lower plate sections are adapted for coupling to heat sensing thermocouples and to a circulating water conduit system for cooling the armor shield/plasma limiter.The inner center portion of each graphite plate is adapted to receive and enclose a section of a circular diagnostic magnetic flux loop so as to minimize the power from the plasma confinement chamber incident upon the flux loop.

  3. Toroidal midplane neutral beam armor and plasma limiter

    DOEpatents

    Kugel, Henry W.; Hand, Jr, Samuel W.; Ksayian, Haig

    1986-01-01

    For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil. The upper and lower plate sections are adapted for coupling to heat sensing thermocouples and to a circulating water conduit system for cooling the armor shield/plasma limiter.The inner center portion of each graphite plate is adapted to receive and enclose a section of a circular diagnostic magnetic flux loop so as to minimize the power from the plasma confinement chamber incident upon the flux loop.

  4. Numerical simulation of armor capability of AI2O3 and SiC armor tiles

    NASA Astrophysics Data System (ADS)

    Rashid, T.; Aleem, M. A.; Akbar, S.; Rauf, A.; Shuaib, M.

    2016-08-01

    Alumina and Silicon Carbide armor plates have been tested numerically against 7.62x51 (mm x mm) armor piercing (AP) projectiles. A 2-D problem with axial symmetry has been designedand the simulations were carried out using commercial software ANSYS AUTODYN. Experiments were modeled for Alumina (99.5%), Alumina (99.7%) and SiC with a range of tile thicknesses (5, 10, 15 and 20 mm). The projectile was chosen as 7.62 x 51AP bullet (initial velocity 810 m/sec)with two different core materials Steel 4340 and WC, however, casing material was copper for both cores. SiC showed better defense against AP bullet as compared to Al2O3. The residual velocity and momentum of the bullet were found to decrease with increasing tile thickness. SiC tiles with thickness 15mm and 20 mm successfully sustained penetration against steel 4340 and WC core bullets, respectively. However none of the Alumina targets succeeded in stopping the bullet.

  5. 27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor...

  6. 27 CFR 478.37 - Manufacture, importation and sale of armor piercing ammunition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and sale of armor piercing ammunition. 478.37 Section 478.37 Alcohol, Tobacco Products, and Firearms..., importation and sale of armor piercing ammunition. No person shall manufacture or import, and no manufacturer or importer shall sell or deliver, armor piercing ammunition, except: (a) The manufacture...

  7. 27 CFR 478.37 - Manufacture, importation and sale of armor piercing ammunition.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... and sale of armor piercing ammunition. 478.37 Section 478.37 Alcohol, Tobacco Products, and Firearms..., importation and sale of armor piercing ammunition. No person shall manufacture or import, and no manufacturer or importer shall sell or deliver, armor piercing ammunition, except: (a) The manufacture...

  8. 27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor...

  9. 27 CFR 478.37 - Manufacture, importation and sale of armor piercing ammunition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and sale of armor piercing ammunition. 478.37 Section 478.37 Alcohol, Tobacco Products, and Firearms..., importation and sale of armor piercing ammunition. No person shall manufacture or import, and no manufacturer or importer shall sell or deliver, armor piercing ammunition, except: (a) The manufacture...

  10. 27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor...

  11. 27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor...

  12. 27 CFR 478.37 - Manufacture, importation and sale of armor piercing ammunition.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... and sale of armor piercing ammunition. 478.37 Section 478.37 Alcohol, Tobacco Products, and Firearms..., importation and sale of armor piercing ammunition. No person shall manufacture or import, and no manufacturer or importer shall sell or deliver, armor piercing ammunition, except: (a) The manufacture...

  13. 27 CFR 478.37 - Manufacture, importation and sale of armor piercing ammunition.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... and sale of armor piercing ammunition. 478.37 Section 478.37 Alcohol, Tobacco Products, and Firearms..., importation and sale of armor piercing ammunition. No person shall manufacture or import, and no manufacturer or importer shall sell or deliver, armor piercing ammunition, except: (a) The manufacture...

  14. 27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor...

  15. 48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and...

  16. 48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and...

  17. 48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and...

  18. 48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and...

  19. 48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and...

  20. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Shield or armor ground resistance measurements. 1755... MATERIALS, AND STANDARD CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall be made on completed lengths of copper cable and...

  1. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Shield or armor ground resistance measurements. 1755... MATERIALS, AND STANDARD CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall be made on completed lengths of copper cable and...

  2. Evaluating the Stability of a Metric for Determining the Health of Armor Plates

    DTIC Science & Technology

    2010-04-13

    premise: The amplitudes and locations of the major vibrational modes of an undamaged armor plate constitute a basic signature of the armor plate...Damaging the armor plate should cause changes to both the amplitude and position of the significant vibrational modes . A metric has been developed to

  3. Evaluating the Stability of a Metric for Determining the Health of Armor Plates

    DTIC Science & Technology

    2011-04-04

    premise: The amplitudes and locations of the major vibrational modes of an undamaged armor plate constitute a basic ?signature? of the armor plate...Damaging the armor plate should cause changes to both the amplitude and position of the significant vibrational modes . A metric has been developed to

  4. Two-dimensional combinatorial screening of a bacterial rRNA A-site-like motif library: defining privileged asymmetric internal loops that bind aminoglycosides.

    PubMed

    Tran, Tuan; Disney, Matthew D

    2010-03-09

    RNAs have diverse structures that are important for biological function. These structures include bulges and internal loops that can form tertiary contacts or serve as ligand binding sites. The most commonly exploited RNA drug target for small molecule intervention is the bacterial ribosome, more specifically the rRNA aminoacyl-tRNA site (rRNA A-site) which is a major target for the aminoglycoside class of antibiotics. The bacterial A-site is composed of a 1 x 1 nucleotide all-U internal loop and a 2 x 1 nucleotide all-A internal loop separated by a single GC base pair. Therefore, we probed the molecular recognition of a small library of four aminoglycosides for binding a 16384-member bacterial rRNA A-site-like internal loop library using two-dimensional combinatorial screening (2DCS). 2DCS is a microarray-based method that probes RNA and chemical spaces simultaneously. These studies sought to determine if aminoglycosides select their therapeutic target if given a choice of binding all possible internal loops derived from an A-site-like library. Results show that the bacterial rRNA A-site was not selected by any aminoglycoside. Analyses of selected sequences using the RNA Privileged Space Predictor (RNA-PSP) program show that each aminoglycoside preferentially binds different types of internal loops. For three of the aminoglycosides, 6''-azido-kanamycin A, 5-O-(2-azidoethyl)-neamine, and 6''-azido-tobramycin, the selected internal loops bind with approximately 10-fold higher affinity than the bacterial rRNA A-site. The internal loops selected to bind 5''-azido-neomycin B bind with an affinity similar to that of the therapeutic target. Selected internal loops that are unique for each aminoglycoside have dissociation constants ranging from 25 to 270 nM and are specific for the aminoglycoside they was selected to bind compared to the other arrayed aminoglycosides. These studies further establish a database of RNA motifs that are recognized by small molecules that

  5. Contemporary body armor: technical data, injuries, and limits.

    PubMed

    Prat, N; Rongieras, F; Sarron, J-C; Miras, A; Voiglio, E

    2012-04-01

    The introduction of firearms in the fifteenth century led to the continuous development of bulletproof personal protection. Due to recent industrial progress and the emergence of a new generation of ballistic fibers in the 1960s, the ability of individual ballistic protections to stop projectiles greatly increased. While protective equipment is able to stop increasingly powerful missiles, deformation during the impact can cause potentially lethal nonpenetrating injuries that are grouped under the generic term of behind armor blunt trauma, and the scope and consequences of these are still unclear. This review first summarizes current technical data for modern bulletproof vests, the materials used in them, and the stopping mechanisms they employ. Then it describes recent research into the specific ballistic injury patterns of soldiers wearing body armor, focusing on behind-armor blunt trauma.

  6. Fabrication of compound nonwoven materials for soft body armor.

    PubMed

    Lin, Chia-Chang; Lin, Jia-Horng; Chang, Chun-Cheng

    2011-09-01

    The primary objective of body armor research is the development of low-cost, lightweight, wearable garments that effectively resist ballistic impact. This study introduces a material intended to reduce nonpenetration trauma by absorbing energy from ballistic impacts. Layers of web were made by low-melting point polyester (LMPET) on unaligned fibers of high-strength polyamide 6 (HSPA6). A compound nonwoven fabric was made by laying high-strength Vectran filaments between two layers of HSPA6-LMPET web. The new fabric underwent needle punching and thermal bonding to form a composite sandwich structure. The new fabric was subjected to a falling weight impact test and a ballistic impact test. The results indicated that the material with the new design reduced maximum indentation depth by 8%. Furthermore, soft body armor made from the material with the new design would cost less to produce and would weigh 22.5% less than conventional soft body armor.

  7. Performance of the PDX neutral beam wall armor

    SciTech Connect

    Kugel, H.W.; Eubank, H.P.; Kozub, T.A.; Williams, M.D.

    1985-02-01

    The PDX wall armor was designed to function as an inner wall thermal armor, a neutral beam diagnostic, and a large area inner toroidal plasma limiter. In this paper we discuss its thermal performance as wall armor during two years of PDX neutral beam heating experiments. During this period it provided sufficient inner wall protection to permit perpendicular heating injections into normal and disruptive plasmas as well as injections in the absence of plasma involving special experiments, calibrations, and tests important for the optimization and development of the PDX neutral beam injection system. Many of the design constraints and performance issues encountered in this work are relevant to the design of larger fusion devices.

  8. Improved resolution of bacteria by high throughput sequence analysis of the rRNA internal transcribed spacer

    PubMed Central

    Ruegger, Paul M.; Clark, Robin T.; Weger, John R.; Braun, Jonathan; Borneman, James

    2014-01-01

    Current high throughput sequencing (HTS) methods are limited in their ability to resolve bacteria at or below the genus level. While the impact of this limitation may be relatively minor in whole-community analyses, it constrains the use of HTS as a tool for identifying and examining individual bacteria of interest. The limited resolution is a consequence of both short read lengths and insufficient sequence variation within the commonly targeted variable regions of the small-subunit rRNA (SSU) gene. The goal of this work was to improve the resolving power of bacterial HTS. We developed an assay targeting the hypervariable rRNA internal transcribed spacer (ITS) region residing between the SSU and large-subunit (LSU) rRNA genes. Comparisons of the ITS region and two SSU regions using annotated bacterial genomes in GenBank showed much greater resolving power is possible with the ITS region. This report presents a new HTS method for analyzing bacterial composition with improved capabilities. The greater resolving power enabled by the ITS region arises from its high sequence variation across a wide range of bacterial taxa and an associated decrease in taxonomic heterogeneity within its OTUs. Although the method should be adaptable to any HTS platform, this report presents PCR primers, amplification parameters, and protocols for Illumina-based analyses. PMID:25034229

  9. Improved resolution of bacteria by high throughput sequence analysis of the rRNA internal transcribed spacer.

    PubMed

    Ruegger, Paul M; Clark, Robin T; Weger, John R; Braun, Jonathan; Borneman, James

    2014-10-01

    Current high throughput sequencing (HTS) methods are limited in their ability to resolve bacteria at or below the genus level. While the impact of this limitation may be relatively minor in whole-community analyses, it constrains the use of HTS as a tool for identifying and examining individual bacteria of interest. The limited resolution is a consequence of both short read lengths and insufficient sequence variation within the commonly targeted variable regions of the small-subunit rRNA (SSU) gene. The goal of this work was to improve the resolving power of bacterial HTS. We developed an assay targeting the hypervariable rRNA internal transcribed spacer (ITS) region residing between the SSU and large-subunit (LSU) rRNA genes. Comparisons of the ITS region and two SSU regions using annotated bacterial genomes in GenBank showed much greater resolving power is possible with the ITS region. This report presents a new HTS method for analyzing bacterial composition with improved capabilities. The greater resolving power enabled by the ITS region arises from its high sequence variation across a wide range of bacterial taxa and an associated decrease in taxonomic heterogeneity within its OTUs. Although the method should be adaptable to any HTS platform, this report presents PCR primers, amplification parameters, and protocols for Illumina-based analyses.

  10. Effects of gender and body adiposity on physiological responses to physical work while wearing body armor.

    PubMed

    Ricciardi, Richard; Deuster, Patricia A; Talbot, Laura A

    2007-07-01

    The purpose of this study was to identify the effects of gender and body adiposity on physiological responses to the stress of wearing body armor. Using a within-subject, repeated-measures design, 37 military personnel volunteered to undergo two experimental conditions, with body armor and without body armor. Female and male subjects with body armor, compared to those without body armor, had no significant differences in percentage increases in aerobic capacity, heart rate, or respiratory rate while walking at slow or moderate pace. However, women, as compared to men, had a significantly increased difference in the rating of perceived physical exertion between wearing and not wearing body armor at a slow pace. Fourteen subjects were not able to complete treadmill testing while wearing body armor because of volitional fatigue and/or limiting dyspnea. Body fat was the best single predictor of treadmill test completion.

  11. Miniaturized hand held microwave interference scanning system for NDE of dielectric armor and armor systems

    SciTech Connect

    Schmidt, Karl F.; Little, Jack R.; Ellingson, William A.; Meitzler, Thomas J.; Green, William

    2011-06-23

    Inspection of ceramic-based armor has advanced through development of a microwave-based, portable, non-contact NDE system. Recently, this system was miniaturized and made wireless for maximum utility in field applications. The electronic components and functionality of the laboratory system are retained, with alternative means of position input for creation of scan images. Validation of the detection capability was recently demonstrated using specially fabricated surrogates and ballistic impact-damaged specimens. The microwave data results have been compared to data from laboratory-based microwave interferometry systems and digital x-ray imaging. The microwave interference scanning has been shown to reliably detect cracks, laminar features and material property variations. The authors present details of the system operation, descriptions of the test samples used and recent results obtained.

  12. Methods of producing armor systems, and armor systems produced using such methods

    DOEpatents

    Chu, Henry S; Lillo, Thomas M; McHugh, Kevin M

    2013-02-19

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  13. Magnesium Technology and Manufacturing for Ultra Lightweight Armored Ground Vehicles

    DTIC Science & Technology

    2009-02-01

    2.3 Corrosion Behavior Several factors that heavily influence the corrosion performance of Mg alloys ( Godard et al., 1967) are alloy chemistry...Based Structural Armor (U), ARL-RP-56, U.S. Army Research Laboratory. Godard , H.P., Jepson, W.P., Bothwell, M.R., and Kane, R.L., Ed., 1967: The

  14. Multifunctionality of chiton biomineralized armor with an integrated visual system

    DOE PAGES

    Li, Ling; Connors, Matthew; Kolle, Mathias; ...

    2015-11-20

    Nature provides a multitude of examples of multifunctional structural materials. There are often trade-offs in these materials because few of them are equally well suited for multiple tasks. One such example is the biomineralized armor of the chiton Acanthopleura granulata, which incorporates an integrated sensory system that includes hundreds of eyes with aragonite-based lens. Here, we used optical experiments to demonstrate directly, for the first time, that these microscopic, mineralized lenses are able to form images. Furthermore, our experiments revealed that the optical performance of these polycrystalline lenses is enhanced by the reduction of spherical aberration through the shape ofmore » the lens and that birefringence scattering is minimized by the use of relatively large, co-aligned grains (~10 μm as compared to ~1 μm in the non-eye regions). Additionally, we used multi-scale mechanical testing techniques to show that A. granulata’s lenses are an integral component of its biomineralized armor, but that both the intrinsic and overall mechanical properties of the lenses are compromised as compared to the primary solid regions of the armor plates. Our results demonstrate that as the size, complexity, and functionality of the integrated sensory elements increases, the local mechanical performance of the armor decreases. But, A. granulata has evolved several strategies to compensate for its local mechanical vulnerabilities to form a multifunctional system with co-optimized overall optical and structural functions.« less

  15. Multifunctionality of chiton biomineralized armor with an integrated visual system

    SciTech Connect

    Li, Ling; Connors, Matthew; Kolle, Mathias; England, Grant; Speiser, Daniel; Xiao, Xianghui; Aizenberg, Joanna; Ortiz, Christine

    2015-11-20

    Nature provides a multitude of examples of multifunctional structural materials. There are often trade-offs in these materials because few of them are equally well suited for multiple tasks. One such example is the biomineralized armor of the chiton Acanthopleura granulata, which incorporates an integrated sensory system that includes hundreds of eyes with aragonite-based lens. Here, we used optical experiments to demonstrate directly, for the first time, that these microscopic, mineralized lenses are able to form images. Furthermore, our experiments revealed that the optical performance of these polycrystalline lenses is enhanced by the reduction of spherical aberration through the shape of the lens and that birefringence scattering is minimized by the use of relatively large, co-aligned grains (~10 μm as compared to ~1 μm in the non-eye regions). Additionally, we used multi-scale mechanical testing techniques to show that A. granulata’s lenses are an integral component of its biomineralized armor, but that both the intrinsic and overall mechanical properties of the lenses are compromised as compared to the primary solid regions of the armor plates. Our results demonstrate that as the size, complexity, and functionality of the integrated sensory elements increases, the local mechanical performance of the armor decreases. But, A. granulata has evolved several strategies to compensate for its local mechanical vulnerabilities to form a multifunctional system with co-optimized overall optical and structural functions.

  16. The Light Armored Cavalry Regiment -- Reconnaissance Force of the Future

    DTIC Science & Technology

    1992-12-01

    appli- que armor made this possible. The Bradely Scout Vehicle, armed with a 25 mm cannon and a wire guided missile system, could now engage and destroy...University Press. 1986 Palmer, David Richard, Summons of the Trumpet. Novato. CA. Presidio Press. 1978. Palmer, Bruce Jr., The 25 Year War. America’s Military

  17. Natural Curaua Fiber-Reinforced Composites in Multilayered Ballistic Armor

    NASA Astrophysics Data System (ADS)

    Monteiro, Sergio Neves; Louro, Luis Henrique Leme; Trindade, Willian; Elias, Carlos Nelson; Ferreira, Carlos Luiz; de Sousa Lima, Eduardo; Weber, Ricardo Pondé; Miguez Suarez, João Carlos; da Silva Figueiredo, André Ben-Hur; Pinheiro, Wagner Anacleto; da Silva, Luis Carlos; Lima, Édio Pereira

    2015-10-01

    The performance of a novel multilayered armor in which the commonly used plies of aramid fabric layer were replaced by an equal thickness layer of distinct curaua fiber-reinforced composites with epoxy or polyester matrices was assessed. The investigated armor, in addition to its polymeric layer (aramid fabric or curaua composite), was also composed of a front Al2O3 ceramic tile and backed by an aluminum alloy sheet. Ballistic impact tests were performed with actual 7.62 caliber ammunitions. Indentation in a clay witness, simulating human body behind the back layer, attested the efficacy of the curaua-reinforced composite as an armor component. The conventional aramid fabric display a similar indentation as the curaua/polyester composite but was less efficient (deeper indentation) than the curaua/epoxy composite. This advantage is shown to be significant, especially in favor of the lighter and cheaper epoxy composite reinforced with 30 vol pct of curaua fiber, as possible substitute for aramid fabric in multilayered ballistic armor for individual protection. Scanning electron microscopy revealed the mechanism associated with the curaua composite ballistic performance.

  18. Lightcurve Analsyis of 774 Armor and 3161 Beadell

    NASA Astrophysics Data System (ADS)

    Oey, Julian; Han, Xianming L.; Gipson, Kevin

    2013-04-01

    Photometric studies of the asteroids 774 Armor and 3161 Beadell and were carried out by observers from Australia and USA. The data were combined and the following periods were obtained: 774 Amor, 25.107 ± 0.005 h; 3161 Beadell, 36.253 ± 0.004 h.

  19. Crack Detection in Armor Plates Using Ultrasonic Techniques (PREPRINT)

    DTIC Science & Technology

    2007-03-01

    A method of using piezoelectric lead zirconate titanate (PZT) transducers to characterize the vibrational modes of Vehicle Body Armor Support System...VBASS) plates and its preliminary results are presented. The amplitude of the vibrational modes of undamaged plates are compared to the vibrational

  20. Crack Detection in Armor Plates Using Ultrasonic Techniques

    DTIC Science & Technology

    2008-06-01

    A method of using piezoelectric lead zirconate titanate (PZT) transducers to characterize the vibrational modes of ceramic Vehicle Body Armor Support...System (VBASS) plates for the purpose of crack detection is presented. The amplitudes of the vibrational modes undamaged plates are compared to the

  1. The Impact of Armor on the Design, Utilization and Survivability of Ground Vehicles: The History of Armor Development and Use

    DTIC Science & Technology

    2012-09-01

    28 Figure 21. Summary of Threats Faced by an Armored Vehicle (From a Abrams Tank System Survivability Briefing in Jan 2012...Figure 32. Comparison of Tracked (Left) (From Cooke 2008) and Wheeled (Right) (From Cooke 2009) Propulsion Systems ...59 Figure 44. Vertical Threat Envelope (From a Abrams Tank System Survivability Briefing in Jan 2012

  2. The life-saving effectiveness of body armor for police officers.

    PubMed

    LaTourrette, Tom

    2010-10-01

    The objective of this study was to determine the effect of protective body armor on a police officer's risk of being killed and estimate the benefits and costs of outfitting police with body armor. In the United States, for police shot in the torso from 2004 to 2007 (n = 262), we calculate the relative risk of death from a gunshot without and with body armor. We estimate the benefit of body armor using the willingness-to-pay approach and compare it with the cost of supplying armor to police not currently wearing armor. The results show that the relative risk of dying without armor is = 3.4 (95% CI: 2.4 to 4.6). Outfitting all police with armor would save at least 8.5 lives per year, resulting in a benefit that is nearly twice the cost, or a net benefit of approximately $100/officer. Body armor more than triples the likelihood that a police officer will survive a shooting to the torso. Outfitting all police with armor yields a positive net benefit and is strongly justified economically.

  3. Multiscale impacts of armoring on Salish Sea shorelines: Evidence for cumulative and threshold effects

    NASA Astrophysics Data System (ADS)

    Dethier, Megan N.; Raymond, Wendel W.; McBride, Aundrea N.; Toft, Jason D.; Cordell, Jeffery R.; Ogston, Andrea S.; Heerhartz, Sarah M.; Berry, Helen D.

    2016-06-01

    Shoreline armoring is widespread in many parts of the protected inland waters of the Pacific Northwest, U.S.A, but impacts on physical and biological features of local nearshore ecosystems have only recently begun to be documented. Armoring marine shorelines can alter natural processes at multiple spatial and temporal scales; some, such as starving the beach of sediments by blocking input from upland bluffs may take decades to become visible, while others such as placement loss of armoring construction are immediate. We quantified a range of geomorphic and biological parameters at paired, nearby armored and unarmored beaches throughout the inland waters of Washington State to test what conditions and parameters are associated with armoring. We gathered identical datasets at a total of 65 pairs of beaches: 6 in South Puget Sound, 23 in Central Puget Sound, and 36 pairs North of Puget Sound proper. At this broad scale, demonstrating differences attributable to armoring is challenging given the high natural variability in measured parameters among beaches and regions. However, we found that armoring was consistently associated with reductions in beach width, riparian vegetation, numbers of accumulated logs, and amounts and types of beach wrack and associated invertebrates. Armoring-related patterns at lower beach elevations (further vertically from armoring) were progressively harder to detect. For some parameters, such as accumulated logs, there was a distinct threshold in armoring elevation that was associated with increased impacts. This large dataset for the first time allowed us to identify cumulative impacts that appear when increasing proportions of shorelines are armored. At large spatial and temporal scales, armoring much of a sediment drift cell may result in reduction of the finer grain-size fractions on beaches, including those used by spawning forage fish. Overall we have shown that local impacts of shoreline armoring can scale-up to have cumulative and

  4. Class A scavenger receptor-mediated dsRNA internalization is independent of innate antiviral signaling and does not require PI3K activity1

    PubMed Central

    Nellimarla, Srinivas; Baid, Kaushal; Loo, Yueh-Ming; Gale, Michael; Bowdish, Dawn M.; Mossman, Karen L.

    2016-01-01

    Double-stranded RNA is a potent trigger of innate immune signaling, eliciting effects within virally infected cells and following release from dying cells. Given its inherent stability, extracellular dsRNA induces both local and systemic effects. Although the class A scavenger receptors (SR-As)3 mediate dsRNA entry, it is unknown if they contribute to signaling beyond ligand internalization. Here, we investigated if SR-As contribute to innate immune signaling independent of the classic TLR and RLR pathways. We generated a stable A549 human epithelial cell line with inducible expression of the Hepatitis C virus protease NS3/4A, which efficiently cleaves TRIF and IPS-1, adaptors for TLR3 and the RLRs respectively. Cells expressing NS3/4A as well as TLR3/MDA5/IPS-1−/− mouse embryonic fibroblasts completely lacked antiviral activity to extracellular dsRNA relative to control cells, suggesting that SR-As do not possess signaling capacity independent of TLR3 or the RLRs. Previous studies implicated PI3K signaling in SR-A-mediated activities and in downstream production of type I interferon. We found that SR-A-mediated dsRNA internalization occurs independent of PI3K activation, while downstream signaling leading to interferon production was partially dependent on PI3K activity. Overall, these findings suggest that SR-A-mediated dsRNA internalization is independent of innate antiviral signaling. PMID:26363049

  5. Secondary RNA structure and nucleotide specificity contribute to internal initiation mediated by the human tau 5′ leader

    PubMed Central

    Veo, Bethany L.; Krushel, Leslie A.

    2012-01-01

    Mechanisms by which eukaryotic internal ribosomal entry sites (IRESs) initiate translation have not been well described. Viral IRESs utilize a combination of secondary/tertiary structure concomitant with sequence specific elements to initiate translation. Eukaryotic IRESs are proposed to utilize the same components, although it appears that short sequence specific elements are more common. In this report we perform an extensive analysis of the IRES in the human tau mRNA. We demonstrate that the tau IRES exhibits characteristics similar to viral IRESs. It contains two main structural domains that exhibit secondary interactions, which are essential for internal initiation. Moreover, the tau IRES is extremely sensitive to small nucleotide substitutions. Our data also indicates that the 40S ribosome is recruited to the middle of the IRES, but whether it scans to the initiation codon in a linear fashion is questioned. Overall, these results identify structural and sequence elements critical for tau IRES activity and consequently, provide a novel target to regulate tau protein expression in disease states including Alzheimer disease and other tauopathies. PMID:22995835

  6. Case study: a novel biomechanical approach for evaluating extended body armor systems.

    PubMed

    Selinger, Jessica C; Gooyers, Chad E; Stevenson, Joan M; Costigan, Patrick A; Chafe, Gabrielle S

    2010-11-01

    To combat the devastating effects of improvised explosive devices (IEDs), body armor that provides extended coverage has been developed. However, this extended coverage increases the armor's weight and may restrict movement. Throughout this case study, a novel technique to assess several armor systems was investigated. Four soldiers performed shoulder and trunk movements while wearing each of the six different armor inserts. Electromyography (EMG) was used to quantify muscular activity and inertial motion sensors were used to determine joint range of motion (ROM). Outcome measures included maximum ROM, integrated EMG, and the soldiers' subjective rankings. For the shoulder tasks, objective ROM and EMG measures were related to each other as well as to subjective rankings and armor material properties. Conversely, little agreement was found between measures for the trunk tasks. Results of this preliminary investigation indicate that combining shoulder ROM and EMG measures has the potential to provide an objective assessment of body armor systems.

  7. The effect of body armor on saving officers' lives: An analysis using LEOKA data.

    PubMed

    Liu, Weiwei; Taylor, Bruce

    2017-02-01

    Using the Law Enforcement Officers Killed and Assaulted (LEOKA; 2002-2011) database, we examined the life-saving effectiveness of body armor while adjusting for a range of confounders not assessed in previous studies. Among the 637 officers who were shot by a firearm at the torso, those who wore body armor were 76% less likely to be killed than those who did not wear armor, controlling for an array of individual and incident characteristics. A number of factors influenced officers' armor wearing behavior include age, BMI, rank, geographic region, and type of assignment. Results will inform law enforcement agencies in assessing gaps in their current policy and help focus limited resources to encourage armor wearing. The investigation of other factors that influence police officers' chance of surviving a gun shooting (while controlling for body armor) will also have important implications for policies related to sending backup officers to police shootings, emergency response, and other critical areas.

  8. Report to the Attorney General on Body Armor Safety Initiative Testing and Activities. Supplement 1

    DTIC Science & Technology

    2004-12-27

    directed the National Institute of Justice (NIJ) to initiate an examination of Zylon ®-based bullet-resistant armor1 (both new and used), to analyze...upgrade kits2 provided by manufacturers to retrofit Zylon ®- based bullet-resistant armors, and to review the existing process by which bullet-resistant...development, standards and testing, and also reviewed information about NIJ’s preliminary evaluation of Zylon ®- based armor. NIJ continues to conduct

  9. Report to the Attorney General on Body Armor Safety Initiative Testing and Activities

    DTIC Science & Technology

    2004-03-11

    4 V. Tests to Determine Zylon Degradation in Used Armor ....................................... 6 A. Phase I: “Worst...Dyneema® produced by DSM, and Zylon ®1 produced by Toyobo. The NIJ body armor testing program has evaluated armor designs that include one specific...The most recent standard is NIJ Standard–0101.04, Revision A, issued in 1 Zylon ® (PBO fiber – Poly-p

  10. Wheels for the Future: Should the U.S. Army Adopt an Armored Wheeled System

    DTIC Science & Technology

    1990-02-05

    firepower, maneuver, and protection. These three measurements of combat power are more defined in six inherent capabilities of armored wheeled systems...AD-A234 372 Wheuls for the Future: Should the U.S. Army Adopt ar, Armored Wheeled System? A MonograpL by Major Glenn Davis Infantry School of...TITLE (nudScutClassification) Wheels For the ýFuture-- Should the US Army Adopt an Armored Wncc led Sybtem?, 2, PERSONAL AUTHCOI S ’ATIA Glenn W, Davis

  11. Shell-armored wood cobbles as a potential criterion for detrital coal deposits

    SciTech Connect

    DiMarco, M.J.; Nummedal, D.

    1986-01-01

    Shell-armored wood cobbles occur on detrital-peat beaches along the seaward edge of the Mississippi Delta. Shell material consists exclusively of Mulinia lateralis, a dwarf surf clam. Soft, heavy, waterlogged wood fragments are abraded and become armored by hard shells in response to wave activity on the beach. Although their preservation potential is suspect, fossilized shell-armored wood clasts would probably be recognized as a type of coal ball and might indicate an allochthonous origin for the host coal.

  12. Friction Stir Weld Failure Mechanisms in Aluminum-Armor Structures Under Ballistic Impact Loading Conditions

    DTIC Science & Technology

    2013-01-01

    FSW joints found in thick aluminum -armor weldments, the overall ballistic performance of 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13...welding ( FSW ) joints found in armor structures made of high-performance aluminum alloys (including solution-strengthened and age-hardenable aluminum alloy...grades). It is argued that due to the large width of FSW joints found in thick aluminum -armor weldments, the overall ballistic performance of the

  13. Neuropilin-1 is a receptor for extracellular miRNA and AGO2/miRNA complexes and mediates the internalization of miRNAs that modulate cell function

    PubMed Central

    Prud'homme, Gerald J.; Glinka, Yelena; Lichner, Zsuzsanna; Yousef, George M.

    2016-01-01

    Extracellular miRNAs are increasingly studied as markers for specific diseases. They are released in biological fluids in a remarkably stable form, and may play a role in intercellular communication. They are thought to be protected against degradation by either encapsulation within microparticles, or by binding to proteins (mostly AGO2). The particulate forms may be internalized by endocytosis or membrane fusion, but the protein-bound forms require a receptor mechanism for their uptake. A major question is whether there are natural cell-membrane receptors that capture and internalize protein-bound functional miRNAs. We examined neuropilin-1 (NRP1), in view of its properties as a receptor for many ligands, including growth factors such as vascular endothelial growth factor (VEGF), and efficiency at mediating ligand internalization. It is expressed by endothelial cells, many other normal cell types, and cancer cells. Here, we report that NRP1 binds miRNAs with high affinity, and promotes their entry into the cell. Furthermore, the internalized miRNAs remain functional, as they specifically regulate proliferation and migration of cancer cells, as well as tube formation by human endothelial cells. Anti-NRP1 antibodies or NRP1 siRNA knockdown block miRNA effects, further confirming NRP1-mediated uptake. VEGF does not compete with miRNAs for binding to NRP1. In addition, NRP1 binds extracellular AGO2 (carrying miRNA or not), and internalizes AGO2/miRNA complexes. Because miRNA bound to AGO2 appears to the most abundant form in body fluids, this may have important physiological and pathological effects. PMID:27486976

  14. Armoring a droplet: Soft jamming of a dense granular interface

    NASA Astrophysics Data System (ADS)

    Lagubeau, Guillaume; Rescaglio, Antonella; Melo, Francisco

    2014-09-01

    Droplets and bubbles protected by armors of particles have found vast applications in encapsulation, stabilization of emulsions and foams, or flotation processes. The liquid phase stores capillary energy, while concurrently the solid contacts of the granular network induce friction and energy dissipation, leading to hybrid interfaces of combined properties. By means of nonintrusive tensiometric methods and structural measurements, we distinguish three surface phases of increasing rigidity during the evaporation of armored droplets. The emergence of surface rigidity is reminiscent of jamming of granular matter, but it occurs differently since it is marked by a step by step hardening under surface compression. These results show that the concept of the effective surface tension remains useful only below the first jamming transition. Beyond this point, the surface stresses become anisotropic.

  15. Multifunctionality of chiton biomineralized armor with an integrated visual system.

    PubMed

    Li, Ling; Connors, Matthew J; Kolle, Mathias; England, Grant T; Speiser, Daniel I; Xiao, Xianghui; Aizenberg, Joanna; Ortiz, Christine

    2015-11-20

    Nature provides a multitude of examples of multifunctional structural materials in which trade-offs are imposed by conflicting functional requirements. One such example is the biomineralized armor of the chiton Acanthopleura granulata, which incorporates an integrated sensory system that includes hundreds of eyes with aragonite-based lenses. We use optical experiments to demonstrate that these microscopic lenses are able to form images. Light scattering by the polycrystalline lenses is minimized by the use of relatively large, crystallographically aligned grains. Multiscale mechanical testing reveals that as the size, complexity, and functionality of the integrated sensory elements increase, the local mechanical performance of the armor decreases. However, A. granulata has evolved several strategies to compensate for its mechanical vulnerabilities to form a multipurpose system with co-optimized optical and structural functions.

  16. Modeling of Bullet Penetration in Explosively Welded Composite Armor Plate

    SciTech Connect

    Joshi, Vasant S.; Carney, Theodore C.

    2006-07-28

    Normal impact of high-speed armor piercing bullet on titanium-steel composite has been investigated using smooth particle hydrodynamics (SPH) code. The objective is to understand the effects of impact during the ballistic testing of explosively welded armor plates. These plates have significant microstructural differences within the weld region, heat-affected zone and the base metal. The variances result in substantial ductility, hardness and strength differences, important criteria in determining the failure mode, specifically whether it occurs at the joint or within the virgin base metal. Several configurations of composite plates with different material combinations were modeled. The results were used to modify the heat treatment process of explosively welded plates, making them more likely to survive impact.

  17. Highly deformable bones: unusual deformation mechanisms of seahorse armor.

    PubMed

    Porter, Michael M; Novitskaya, Ekaterina; Castro-Ceseña, Ana Bertha; Meyers, Marc A; McKittrick, Joanna

    2013-06-01

    Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting. The bony plates are highly deformable materials designed to slide past one another and buckle when compressed. This complex plate and segment motion, along with the unique hardness distribution and structural hierarchy of each plate, provide seahorses with joint flexibility while shielding them against impact and crushing. Mimicking seahorse armor may lead to novel bio-inspired technologies, such as flexible armor, fracture-resistant structures or prehensile robotics.

  18. Armoring a droplet: soft jamming of a dense granular interface.

    PubMed

    Lagubeau, Guillaume; Rescaglio, Antonella; Melo, Francisco

    2014-09-01

    Droplets and bubbles protected by armors of particles have found vast applications in encapsulation, stabilization of emulsions and foams, or flotation processes. The liquid phase stores capillary energy, while concurrently the solid contacts of the granular network induce friction and energy dissipation, leading to hybrid interfaces of combined properties. By means of nonintrusive tensiometric methods and structural measurements, we distinguish three surface phases of increasing rigidity during the evaporation of armored droplets. The emergence of surface rigidity is reminiscent of jamming of granular matter, but it occurs differently since it is marked by a step by step hardening under surface compression. These results show that the concept of the effective surface tension remains useful only below the first jamming transition. Beyond this point, the surface stresses become anisotropic.

  19. Armoring and vertical sorting in aeolian dune fields

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Narteau, Clément; Rozier, Olivier

    2016-04-01

    Unlike ripples, there are only few numerical studies on grain-size segregation at the scale of dunes in aeolian environments. Here we use a cellular automaton model to analyze vertical sorting in granular mixtures under steady unidirectional flow conditions. We investigate the feedbacks between dune growth and the segregation mechanisms by varying the size of coarse grains and their proportion within the bed. We systematically observe the development of a horizontal layer of coarse grains at the top of which sorted bed forms may grow by amalgamation. The formation of such an armor layer controls the overall sediment transport and availability. The emergence of dunes and the transition from barchan to transverse dune fields depend only on the grain size distribution of the initial sediment layer. As confirmed by observation, this result indicates that armor layers should be present in most arid deserts, where they are likely to control dune morphodynamics.

  20. Armor corrosion monitoring of a submarine AC cable

    SciTech Connect

    Genesca, J.; Perez, T.; Lara, C.

    1997-12-01

    After the hurricane Gilberto flattened (devastated) Cancun in September 1988, the submarine cables which supplied electricity to Isla Mjueres Island remained very damaged, and it was decided to install the new ones. In 1989, four new submarine cables were installed from Punta Sam, Cancun to Isla Mujeres. Such cables, of nominal tension 34.5 KV, were manufactures with a galvanized steel armor coated with asphalt, and began operation during 1990. The object of this communication is to present the experimental procedure that gave place to the armor corrosion monitoring procedure carried out in this particular case and to compare the results with those obtained on the field. Results of the cathodic protection system applied are also presented.

  1. [Search for optimal combinations of the hygienic and protective characteristics of body armors].

    PubMed

    Logatkin, S M

    2008-01-01

    The protective composition of a body armor is generally characterized by two major parameters--the area and level of protection, i.e. resistance to bullets and fragments. These characteristics directly depend on the mass of a body armor and the sizes of the body's screening. The positive protective characteristics simultaneously have a negative impact on the most important hygienic indices of a body armor, such as convenience and easiness-to-use. The optimum combination of protective and performance characteristics of body armors makes a compromise between their mass and the level of protection.

  2. Effect of Spot and Stud Welding on ESR 4340 Steel Armor.

    DTIC Science & Technology

    1978-02-01

    ESR ) 4340 steel armor. MATERIALS The armor used in this program was commercially produced ESR 4340 steeL in thicknesses of...N — AO—AO5k 025 ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTO——ETC F/S 13/5 EFFECT OF SPOT AND STUD WELDING ON ESR 14314 0 STEEL ARMOR. (U...5 lAD I ~ EFFECT OF SPOT~AND STUD WELDING ON ESR 434O~ STEEL ARMOR~ ~~ - /, ‘ , ~ . ~~~ — ~ — ~~~ — , ~~~~~~ ——-...—- ( -~~/ ~~~ - ‘~/ ~~~ ‘ .

  3. Mechanisms of stability of armored bubbles: FY 1996 Final Report

    SciTech Connect

    Rossen, W.R.; Kam, S.I.

    1996-11-01

    Theoretical and experimental studies examine how a coating, or {open_quotes}armor,{close_quotes} of partially wetted solid particles can stabilize tiny bubbles against diffusion of gas into the surrounding liquid, in spite of the high capillary pressures normally associated with such bubbles. Experiments with polymethylmethacrylate (PNMA) beads and carbonated water demonstrate that armored bubbles can persist for weeks in liquid unsaturated with respect to the gas in the bubbles. This question is of concern regarding gas discharges from waste tanks at the Hanford reservation. The stresses on the solid-solid contacts between particles in such cases is large and could drive sintering of the particles into a rigid framework. Stability analysis suggests that a slightly shrunken bubble would not expel a solid particle from its armor to relieve stress and allow the bubble to shrink further. Expulsion of particles from more stressed bubbles at zero capillary pressure is energetically favored in some cases. It is not clear, however, whether this expulsion would proceed spontaneously from a small perturbation or require a large initial disturbance of the bubble. In some cases, it appears that a bubble would expel some particles and shrink, but the bubble would approach a final, stable size rather than disappear completely. This simplified analysis leaves out several factors. For instance, only one perturbation toward expelling a solid from the armor is considered; perhaps other perturbations would be more energetically favored than that tested. Other considerations (particle deformation, surface roughness, contact-angle hysteresis, and adhesion or physical bonding between adjacent particles) would make expelling solids more difficult than indicated by this theoretical study.

  4. Fractographic Analysis of Long Rod Penetrator-Armor Ceramic Interactions

    DTIC Science & Technology

    1989-10-01

    a 97 wcight-pcrccnt tungsten (97 W) long-rod penietrator with an aspect ratio of’ 10 (L/D = 10) and a laminate armor package consisting of steel ESR ...carefully moved so as not to disturb the comminuted material. The ESR 4340 back plate was removed from the target and the comminuted ceramic was... steel particles were included in the ceramic powder.\\ The steel was present from thrce sources: front plate penetration, back plate splash, and

  5. Lightweight armor system and process for producing the same

    DOEpatents

    Chu, Henry S.; Bruck, H. Alan; Strempek, Gary C.; Varacalle, Jr., Dominic J.

    2004-01-20

    A lightweight armor system may comprise a substrate having a graded metal matrix composite layer formed thereon by thermal spray deposition. The graded metal matrix composite layer comprises an increasing volume fraction of ceramic particles imbedded in a decreasing volume fraction of a metal matrix as a function of a thickness of the graded metal matrix composite layer. A ceramic impact layer is affixed to the graded metal matrix composite layer.

  6. Survivability Analysis for the Evaluation of Personnel in Body Armor

    DTIC Science & Technology

    2010-10-01

    system survivability/lethality/vulnerability ( SLV ) analyses using a software package called MUVES-S2. MUVES-S2 is an Army developed and maintained SLV ...methodology, highlighting improved capabilities and new techniques for performing SLV analyses of personnel wearing various body armor configurations. We...combat system survivability/lethality/vulnerability ( SLV ) analyses using a software package called MUVES-S2. MUVES-S2 is an Army developed and

  7. DoD Testing Requirements for Body Armor

    DTIC Science & Technology

    2009-01-29

    Arlington, VA 22202-4704 Acronyms and Abbreviations BFD Back Face Deformation COPD Contract Purchase Description COTR...established in the Contract Purchase Description ( COPD ) or performance specification. Those parameters include the acceptable number of complete and...determined by shooting the piece of armor several times, with the same type of threat, across a broad range of velocities. The COPD contains the V50

  8. Low Cost Sintering of Titanium Diboride for Armor

    DTIC Science & Technology

    1988-10-01

    V. . . . ri + 1 Ii l ’ I I List of Tables Table Nuba Title I List of Pcwder Lot Numbers and Quantities of ’iB2 Powder Produced for MTL...February 03. -13- Table I List of Powder Lot Numbers and Quantities of TiB2 Powder Produced for MTL Armor Contract (DAAL04-86.C.0041) "Lot Original

  9. Rapid identification of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) using ribosomal RNA internal transcribed spacer 1.

    PubMed

    Perera, Omaththage P; Allen, Kerry C; Jain, Devendra; Purcell, Matthew; Little, Nathan S; Luttrell, Randall G

    2015-01-01

    Rapid identification of invasive species is crucial for deploying management strategies to prevent establishment. Recent Helicoverpa armigera (Hübner) invasions and subsequent establishment in South America has increased the risk of this species invading North America. Morphological similarities make differentiation of H. armigera from the native Helicoverpa zea (Boddie) difficult. Characteristics of adult male genitalia and nucleotide sequence differences in mitochondrial DNA are two of the currently available methods to differentiate these two species. However, current methods are likely too slow to be employed as rapid detection methods. In this study, conserved differences in the internal transcribed spacer 1 (ITS1) of the ribosomal RNA genes were used to develop species-specific oligonucleotide primers that amplified ITS1 fragments of 147 and 334 bp from H. armigera and H. zea, respectively. An amplicon (83 bp) from a conserved region of 18S ribosomal RNA subunit served as a positive control. Melting temperature differences in ITS1 amplicons yielded species-specific dissociation curves that could be used in high resolution melt analysis to differentiate the two Helicoverpa species. In addition, a rapid and inexpensive procedure for obtaining amplifiable genomic DNA from a small amount of tissue was identified. Under optimal conditions, the process was able to detect DNA from one H. armigera leg in a pool of 25 legs. The high resolution melt analysis combined with rapid DNA extraction could be used as an inexpensive method to genetically differentiate large numbers of H. armigera and H. zea using readily available reagents.

  10. A clothing modeling framework for uniform and armor system design

    NASA Astrophysics Data System (ADS)

    Man, Xiaolin; Swan, Colby C.; Rahmatalla, Salam

    2006-05-01

    In the analysis and design of military uniforms and body armor systems it is helpful to quantify the effects of the clothing/armor system on a wearer's physical performance capabilities. Toward this end, a clothing modeling framework for quantifying the mechanical interactions between a given uniform or body armor system design and a specific wearer performing defined physical tasks is proposed. The modeling framework consists of three interacting modules: (1) a macroscale fabric mechanics/dynamics model; (2) a collision detection and contact correction module; and (3) a human motion module. In the proposed framework, the macroscopic fabric model is based on a rigorous large deformation continuum-degenerated shell theory representation. The collision and contact module enforces non-penetration constraints between the fabric and human body and computes the associated contact forces between the two. The human body is represented in the current framework, as an assemblage of overlapping ellipsoids that undergo rigid body motions consistent with human motions while performing actions such as walking, running, or jumping. The transient rigid body motions of each ellipsoidal body segment in time are determined using motion capture technology. The integrated modeling framework is then exercised to quantify the resistance that the clothing exerts on the wearer during the specific activities under consideration. Current results from the framework are presented and its intended applications are discussed along with some of the key challenges remaining in clothing system modeling.

  11. Toroidal midplane neutral beam armor and plasma limiter

    DOEpatents

    Kugel, H.W.; Hand, S.W. Jr.; Ksayian, H.

    1985-05-31

    This invention contemplates an armor shield/plasma limiter positioned upon the inner wall of a toroidal vacuum chamber within which is magnetically confined an energetic plasma in a tokamak nuclear fusion reactor. The armor shield/plasma limiter is thus of a general semi-toroidal shape and is comprised of a plurality of adjacent graphite plates positioned immediately adjacent to each other so as to form a continuous ring upon and around the toroidal chamber's inner wall and the reactor's midplane coil. Each plate has a generally semi-circular outer circumference and a recessed inner portion and is comprised of upper and lower half sections positioned immediately adjacent to one another along the midplane of the plate. With the upper and lower half sections thus joined, a channel or duct is provided within the midplane of the plate in which a magnetic flux loop is positioned. The magnetic flux loop is thus positioned immediately adjacent to the fusing toroidal plasma and serves as a diagnostic sensor with the armor shield/plasma limiter minimizing the amount of power from the energetic plasma as well as from the neutral particle beams heating the plasma incident upon the flux loop.

  12. DNA polymorphism in morels: complete sequences of the internal transcribed spacer of genes coding for rRNA in Morchella esculenta (yellow morel) and Morchella conica (black morel).

    PubMed

    Wipf, D; Munch, J C; Botton, B; Buscot, F

    1996-09-01

    The internal transcribed spacer (ITS) of the gene coding for rRNA was sequenced in both directions with the gene walking technique in a black morel (Morchella conica) and a yellow morel (M. esculenta) to elucidate the ITS length discrepancy between the two species groups (750-bp ITS in black morels and 1,150-bp ITS in yellow morels.

  13. Enhanced protein expression by internal ribosomal entry site-driven mRNA translation as a novel approach for in vitro loading of dendritic cells with antigens.

    PubMed

    Tan, Xiaohua; Wan, Yonghong

    2008-01-01

    Transfection of dendritic cells (DCs) with messenger RNAs (mRNAs) of tumor-associated antigens (TAAs) is a promising strategy for cancer vaccines. TAA mRNA can be generated by in vitro transcription using DNA encoding the TAA gene as a template. A cap analog is usually added upon in vitro transcription to stabilize mRNA and enhance the efficiency of mRNA translation. However, the inclusion of the cap analog correlates with significantly lower-yield mRNA transcription, potentially leading to an expensive vaccine manufacturing process. To solve this problem, we present a novel approach in which DNA templates are modified with an internal ribosomal entry site (IRES) sequence inserted upstream of the gene of interest to replace the use of the cap analog. The presence of IRES greatly enhanced transcription for the mRNA in vitro compared with the cap analog. Also, higher transgene expression was achieved using luciferase (Luc) mRNA with IRES than using capped Luc mRNA to transfect DCs. Immunization of mice with DCs transfected with IRES-containing mRNA encoding chicken ovalbumin (OVA) induced significant levels of antigen-specific interferon gamma-producing CD8(+) T cells and in vivo killing of antigen-bearing cells. Consistently, mice immunized with IRES-containing OVA mRNA-transfected DCs were protected from pulmonary metastasis of melanoma cells injected intravenously. We suggest that IRES can be used for the production of larger quantities of mRNA and that such IRES-containing mRNAs may be useful for DC-based antitumor immunotherapy.

  14. Characterizing the interaction among bullet, body armor, and human and surrogate targets.

    PubMed

    Shen, Weixin; Niu, Yuqing; Bykanova, Lucy; Laurence, Peter; Link, Norman

    2010-12-01

    This study used a combined experimental and modeling approach to characterize and quantify the interaction among bullet, body armor, and human surrogate targets during the 10-1000 μs range that is crucial to evaluating the protective effectiveness of body armor against blunt injuries. Ballistic tests incorporating high-speed flash X-ray measurements were performed to acquire the deformations of bullets and body armor samples placed against ballistic clay and gelatin targets with images taken between 10 μs and 1 ms of the initial impact. Finite element models (FEMs) of bullet, armor, and gelatin and clay targets were developed with material parameters selected to best fit model calculations to the test measurements. FEMs of bullet and armor interactions were then assembled with a FEM of a human torso and FEMs of clay and gelatin blocks in the shape of a human torso to examine the effects of target material and geometry on the interaction. Test and simulation results revealed three distinct loading phases during the interaction. In the first phase, the bullet was significantly slowed in about 60 μs as it transferred a major portion of its energy into the body armor. In the second phase, fibers inside the armor were pulled toward the point of impact and kept on absorbing energy until about 100 μs after the initial impact when energy absorption reached its peak. In the third phase, the deformation on the armor's back face continued to grow and energies inside both armor and targets redistributed through wave propagation. The results indicated that armor deformation and energy absorption in the second and third phases were significantly affected by the material properties (density and stiffness) and geometrical characteristics (curvature and gap at the armor-target interface) of the targets. Valid surrogate targets for testing the ballistic resistance of the armor need to account for these factors and produce the same armor deformation and energy absorption as on a

  15. Evolution of the ribosomal RNA internal transcribed spacer one (ITS-1) in cichlid fishes of the Lake Victoria region.

    PubMed

    Booton, G C; Kaufman, L; Chandler, M; Oguto-Ohwayo, R; Duan, W; Fuerst, P A

    1999-03-01

    The nucleotide sequences of the first internal transcribed spacer (ITS-1) of the ribosomal RNA gene cluster have been determined for 11 species of closely related endemic cichlid fishes of the Lake Victoria region (LVR) and 6 related East African cichlids. The ITS-1 sequences confirmed independently derived basal phylogenies, but provide limited insight within this species flock. The line leading to Pseudocrenilabrus multicolor arose early, close to the divergence event that separated the tilapiine and haplochromine tribes of the "African Group" of the family Cichlidae. In this phylogeny, Astatoreochromis alluaudi and the riverine Astatotilapia burtoni are sister taxa, which together are a sister group to a monophyletic assemblage including both Lake Victoria and Lake Edward taxa. The ITS-1 data support the monophyly of haplochromine genera across lakes. Since Lake Victoria is believed to have been dry between 14, 500 and 12,400 BPE, the modern assemblage must have been derived from reinvasion by the products of earlier cladogenesis events. Thus, although the regional superflock is monophyletic, the haplochromines of Lake Victoria itself did not evolve in situ from a single ancestor.

  16. 27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Armor piercing ammunition... Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The provisions of §§ 478.37 and 478.99(d) with respect to the manufacture or importation of armor...

  17. 27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Armor piercing ammunition... Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The provisions of §§ 478.37 and 478.99(d) with respect to the manufacture or importation of armor...

  18. 27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Armor piercing ammunition... Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The provisions of §§ 478.37 and 478.99(d) with respect to the manufacture or importation of armor...

  19. 27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Armor piercing ammunition... Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The provisions of §§ 478.37 and 478.99(d) with respect to the manufacture or importation of armor...

  20. 27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Armor piercing ammunition... Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The provisions of §§ 478.37 and 478.99(d) with respect to the manufacture or importation of armor...

  1. Development, Field Test, and Refinement of Performance Training Programs in Armor Advanced Individual Training. Final Report.

    ERIC Educational Resources Information Center

    Young, Douglas L.; Taylor, John E.

    Performance-oriented instruction was developed, field tested, and refined in two Advanced Individual Training (AIT) programs--Armor Reconnaissance Specialist (MOS 11D) and Armor Crewman (MOS 11E). Tasks for both MOS (Military Occupational Specialty) were inventoried and the inventories were reduced by eliminating those tasks which are not required…

  2. Body armor, performance, and physiology during repeated high-intensity work tasks.

    PubMed

    Larsen, Brianna; Netto, Kevin; Skovli, Daniel; Vincs, Kim; Vu, Sarah; Aisbett, Brad

    2012-11-01

    This study examined the effect of body armor during repeated, intermittent high-intensity simulated military work. Twelve males performed 11 repetitions of a military style circuit, wearing no armor on one occasion and full armor (approximately 17 kg) on another. Performance was measured by the time to complete individual work tasks plus overall circuit time to completion. Heart rate, intestinal temperature, and rating of perceived exertion were recorded after each circuit. Participants' circuit time to completion was 7.3 +/- 1.0 seconds slower (p <0.01) when wearing armor. Shooting, vaulting, and crawling were also slower (0.8 +/- 0.2, 0.4 +/- 0.2, and 1.0 +/- 0.4 seconds, respectively; all p < or = 0.05). No differences were observed for box lifting. Higher core temperatures were reported for the armor condition for circuit's 7 to 11 (p = 0.01-0.05). Rating of perceived exertion was higher (1 +/- 0; p = 0.03) when wearing armor. No differences were observed for heart rate. Wearing armor impairs repeated high-intensity military task performance. In the relatively short work time utilized, this decrement did not accrue over time. The impairment may, then, be related to the armor load, rather than accumulating fatigue.

  3. Demonstrating Nonhexavelent Chrome Steel Conversion Coatings on Stryker High Hard Armor Steel Hatches

    DTIC Science & Technology

    2014-01-01

    protection against armor-piercing threats, these steels corrode rapidly without the use of a good corrosion protective coating ...stress corrosion cracking. • Provides a more robust process that will protect against deficiencies in the inorganic coating process. Advantages...of other systems provide good protection against armor-piercing threats. However, these steels corrode rapidly without good corrosion protective

  4. Inspecting Composite Ceramic Armor Using Advanced Signal Processing Together with Phased Array Ultrasound

    DTIC Science & Technology

    2010-01-08

    processing techniques have been developed to help improve phased array ultrasonic inspection and analysis of multi-layered ceramic armor panels. The...INSPECTING COMPOSITE CERAMIC ARMOR USING ADVANCED SIGNAL PROCESSING TOGETHER WITH PHASED ARRAY ULTRASOUND J. S. Steckenrider Illinois College...immersion phased array ultrasound system. Some of these specimens had intentional design defects inserted interior to the specimens. Because of the very

  5. Dynamic Material Properties of Orthotropic Polymer and Molybdenum for Use in Next Generation Composite Armor Concept?

    DTIC Science & Technology

    2011-06-01

    defeating Tantalum projectile while armor grade steel (right) failed This numerical model used for these simulations was developed using the Autodyn ...simulation using the hydro code AUTODYNE ® was performed to further verify the validity of the layered armor concept. 8 THIS PAGE INTENTIONALLY LEFT

  6. 48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate....

  7. 48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate....

  8. 48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate....

  9. 48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate....

  10. 48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate....

  11. 76 FR 22920 - Stab Resistance of Personal Body Armor (2000) Standard Special Technical Committee Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Office of Justice Programs Stab Resistance of Personal Body Armor (2000) Standard Special Technical... Institute of Justice (NIJ) is in the process of revising its Stab Resistance of Personal Body Armor...

  12. 30 CFR 75.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... conduits enclosing power conductors. 75.700 Section 75.700 Mineral Resources MINE SAFETY AND HEALTH... Grounding § 75.700 Grounding metallic sheaths, armors, and conduits enclosing power conductors. All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically continuous throughout...

  13. Origin of the 44-mm behind-armor blunt trauma standard.

    PubMed

    Hanlon, Erin; Gillich, Patrick

    2012-03-01

    A number of armed assaults on public officials occurred in the early 1970s, which prompted the Lightweight Soft Body Armor Program to develop modern, concealable, soft body armor. Methodology needed to be developed to (1) determine the effectiveness of the soft body armor to stop bullet penetration and (2) assess the potential injury from nonpenetrating blunt impacts to the body. Extensive research was performed under the program to develop methodologies to assess soft body armor, including behind-armor blunt trauma (BABT) evaluation. This methodology is still used today, and it has been applied extensively beyond the original intent. However, the origin of this methodology is not well understood by many researchers in the various fields in which it is being applied because the original documentation is difficult to obtain. Therefore, the purpose of this article is to provide a comprehensive review of the BABT to offer researchers information about its history and limitations.

  14. Ballistic Performance of Alimina/S-2 Glass-Reinforced Polymer-Matrix Composite Hybrid Lightweight Armor Against Armor Piercing (AP) and Non-AP Projectiles

    DTIC Science & Technology

    2007-01-01

    Armor Piercing Projectile, Fragment Simulating Projectile, Ceramic/Composite Hybrid Armor, AUTODYN NOMENCLATURE A - Material Specific Constant...Phenomena All the calculations carried out in the present work are done using AUTODYN , a general purpose non-linear dynamics modeling and simulation...software [8]. AUTODYN falls into a group of computer programs known as “hydrocodes”, which are particularly suited for modeling explosion, blast, impact

  15. Enhanced stab resistance of armor composites with functionalized silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Mahfuz, Hassan; Clements, Floria; Rangari, Vijaya; Dhanak, Vinod; Beamson, Graham

    2009-03-01

    Traditionally shear thickening fluid (STF) reinforced with Kevlar has been used to develop flexible armor. At the core of the STF-Kevlar composites is a mixture of polyethylene glycol (PEG) and silica particles. This mixture is often known as STF and is consisted of approximately 45 wt % PEG and 55 wt % silica. During rheological tests, STF shows instantaneous spike in viscosity above a critical shear rate. Fabrication of STF-Kevlar composites requires preparation of STF, dilution with ethanol, and then impregnation with Kevlar. In the current approach, nanoscale silica particles were dispersed directly into a mixture of PEG and ethanol through a sonic cavitation process. Two types of silica nanoparticles were used in the investigation: 30 nm crystalline silica and 7 nm amorphous silica. The admixture was then reinforced with Kevlar fabric to produce flexible armor composites. In the next step, silica particles are functionalized with a silane coupling agent to enhance bonding between silica and PEG. The performance of the resulting armor composites improved significantly. As evidenced by National Institute of Justice spike tests, the energy required for zero-layer penetration (i.e., no penetration) jumped twofold: from 12 to 25 J cm2/g. The source of this improvement has been traced to the formation of siloxane (Si-O-Si) bonds between silica and PEG and superior coating of Kevlar filaments with particles. Fourier transform infrared, x-ray photoemission spectroscopy, and scanning electron microscopy studies were performed to examine chemical bonds, elemental composition, and particle dispersion responsible for such improvement. In summary, our experiments have demonstrated that functionalization of silica particles followed by direct dispersion into PEG resulted in superior Kevlar composites having much higher spike resistance.

  16. Ballistic Resistance of Body Armor. NIJ Standard-0101.06

    DTIC Science & Technology

    2008-07-01

    Fahrenheit lbf pound force rf radio frequency diam diameter lbf⋅in pound force inch rh relative humidity emf electromotive force lm lumen s second...the surface that should face the incoming ballistic threat. Also, the side of the armor opposite the wear face (see 3.51 Wear Face). 3.47 Test Series ...sequence and before each 12 shot BL test sequence. During P-BFS testing, a post-test drop series shall also be performed immediately following the last

  17. Simulation of armor penetration by tungsten rods: ALEGRA validation report

    SciTech Connect

    Carroll, D.E.; Hertel, E.S. Jr.; Trucano, T.G.

    1997-11-01

    Results from simulations of the impact and penetration of tungsten alloy rods into thick rolled armor plates are presented. The calculations were performed with the CTH and ALEGRA computer codes using the DOE massively parallel TFLOPS computer co-developed by Sandia National Laboratory and Intel Corporation. Comparisons with experimental results are presented. Agreement of the two codes with each other and with the empirical results for penetration channel depth and radius is very close. Other shock physics and penetration features are also compared to simulation results.

  18. The Army Needs a Strategic Armored Gun System--Now

    DTIC Science & Technology

    1991-04-05

    the AGS ROC. IVECO- Fiat, The Italian firm o4 IVECO- Fiat has proposed three variants as candidates for the AGS! - The Centauro 9x8 wheeled light...armored vehicle with OTO Melana, i05mm turret. - The Centauro SxO with the Cadillac-Gage 105mm turret mounting the Royal Ordnance L-7 105mm gun. - The... Centauro 6x6 with the LAV-i10mm turret and EX-35 gun. The three systems cannot meet many of the AGE requirements# primarily weightp since the heaviest

  19. An Internal Ribosome Entry Site Directs Translation of the 3′-Gene from Pelargonium Flower Break Virus Genomic RNA: Implications for Infectivity

    PubMed Central

    Fernández-Miragall, Olga; Hernández, Carmen

    2011-01-01

    Pelargonium flower break virus (PFBV, genus Carmovirus) has a single-stranded positive-sense genomic RNA (gRNA) which contains five ORFs. The two 5′-proximal ORFs encode the replicases, two internal ORFs encode movement proteins, and the 3′-proximal ORF encodes a polypeptide (p37) which plays a dual role as capsid protein and as suppressor of RNA silencing. Like other members of family Tombusviridae, carmoviruses express ORFs that are not 5′-proximal from subgenomic RNAs. However, in one case, corresponding to Hisbiscus chlorotic ringspot virus, it has been reported that the 3′-proximal gene can be translated from the gRNA through an internal ribosome entry site (IRES). Here we show that PFBV also holds an IRES that mediates production of p37 from the gRNA, raising the question of whether this translation strategy may be conserved in the genus. The PFBV IRES was functional both in vitro and in vivo and either in the viral context or when inserted into synthetic bicistronic constructs. Through deletion and mutagenesis studies we have found that the IRES is contained within a 80 nt segment and have identified some structural traits that influence IRES function. Interestingly, mutations that diminish IRES activity strongly reduced the infectivity of the virus while the progress of the infection was favoured by mutations potentiating such activity. These results support the biological significance of the IRES-driven p37 translation and suggest that production of the silencing suppressor from the gRNA might allow the virus to early counteract the defence response of the host, thus facilitating pathogen multiplication and spread. PMID:21818349

  20. The NMR Structure of an Internal Loop from 23S Ribosomal RNA Differs from its Structure in Crystals of 50S Ribosomal Subunits

    PubMed Central

    Shankar, Neelaabh; Kennedy, Scott D.; Chen, Gang; Krugh, Thomas R.; Turner, Douglas H.

    2014-01-01

    Internal loops play an important role in structure and folding of RNA and in RNA recognition by other molecules such as proteins and ligands. An understanding of internal loops with propensities to form a particular structure will help predict RNA structure, recognition, and function. The structures of internal loops 5'1009CUAAG10133'3'1168GAAGC11645' and 5'998CUAAG10023'3'1157GAAGC11535' from helix 40 of the large subunit rRNA in Deinococcus radiodurans and Escherichia coli, respectively, are phylogenetically conserved, suggesting functional relevance. The energetics and NMR solution structure of the loop were determined in the duplex, 5'1GGCUAAGAC93'3'18CCGAAGCUG105' The internal loop forms a different structure in solution than in the crystal structures of the ribosomal subunits. In particular, the crystal structures have a bulged out adenine at the equivalent of position A15 and a reverse Hoogsteen UA pair (trans Watson-Crick/Hoogsteen UA) at the equivalent of U4 and A14, whereas the solution structure has a single hydrogen bond UA pair (cis Watson-Crick/sugar edge A15U4) between U4 and A15 and a sheared AA pair (trans Hoogsteen/sugar edge A14A5) between A5 and A14. There is cross-strand stacking between A6 and A14 (A6/A14/A15 stacking pattern) in the NMR structure. All three structures have a sheared GA pair (trans Hoogsteen/sugar edge A6G13) at the equivalent of A6 and G13. The internal loop has contacts with ribosomal protein L20 and other parts of the RNA in the crystal structures. These contacts presumably provide the free energy to rearrange the base pairing in the loop. Evidently, molecular recognition of this internal loop involves induced fit binding, which could confer several advantages. The predicted thermodynamic stability of the loop agrees with the experimental value, even though the thermodynamic model assumes a Watson–Crick UA pair. PMID:17002278

  1. Numerical simulation of armored vehicles subjected to undercarriage landmine blasts

    NASA Astrophysics Data System (ADS)

    Erdik, A.; Kilic, S. A.; Kilic, N.; Bedir, S.

    2016-07-01

    Landmine threats play a crucial role in the design of armored personnel carriers. Therefore, a reliable blast simulation methodology is valuable to the vehicle design development process. The first part of this study presents a parametric approach for the quantification of the important factors such as the incident overpressure, the reflected overpressure, the incident impulse, and the reflected impulse for the blast simulations that employ the Arbitrary Lagrangian-Eulerian formulation. The effects of mesh resolution, mesh topology, and fluid-structure interaction (FSI) parameters are discussed. The simulation results are compared with the calculations of the more established CONventional WEaPons (CONWEP) approach based on the available experimental data. The initial findings show that the spherical topology provides advantages over the Cartesian mesh domains. Furthermore, the FSI parameters play an important role when coarse Lagrangian finite elements are coupled with fine Eulerian elements at the interface. The optimum mesh topology and the mesh resolution of the parametric study are then used in the landmine blast simulation. The second part of the study presents the experimental blast response of an armored vehicle subjected to a landmine explosion under the front left wheel in accordance with the NATO AEP-55 Standard. The results of the simulations show good agreement with the experimental measurements.

  2. Ceramic/polymer functionally graded material (FGM) lightweight armor system

    SciTech Connect

    Petrovic, J.J.; McClellan, K.J.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and with liquid polymers at room temperature. Thus, they were able to demonstrate the feasibility of producing boron carbide-aluminum and boron carbide-polymer functionally graded materials.

  3. Superelement Analysis of Tile-Reinforced Composite Armor

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.

    1998-01-01

    Super-elements can greatly improve the computational efficiency of analyses of tile-reinforced structures such as the hull of the Composite Armored Vehicle. By taking advantage of the periodicity in this type of construction, super-elements can be used to simplify the task of modeling, to virtually eliminate the time required to assemble the stiffness matrices, and to reduce significantly the analysis solution time. Furthermore, super-elements are fully transferable between analyses and analysts, so that they provide a consistent method to share information and reduce duplication. This paper describes a methodology that was developed to model and analyze large upper hull components of the Composite Armored Vehicle. The analyses are based on two types of superelement models. The first type is based on element-layering, which consists of modeling a laminate by using several layers of shell elements constrained together with compatibility equations. Element layering is used to ensure the proper transverse shear deformation in the laminate rubber layer. The second type of model uses three-dimensional elements. Since no graphical pre-processor currently supports super-elements, a special technique based on master-elements was developed. Master-elements are representations of super-elements that are used in conjunction with a custom translator to write the superelement connectivities as input decks for ABAQUS.

  4. Molecular analysis of the 16S-23S rDNA internal spacer region (ISR) and truncated tRNA(Ala) gene segments in Campylobacter lari.

    PubMed

    Hayashi, K; Tazumi, A; Nakanishi, S; Nakajima, T; Matsubara, K; Ueno, H; Moore, J E; Millar, B C; Matsuda, M

    2012-06-01

    Following PCR amplification and sequencing, nucleotide sequence alignment analyses demonstrated the presence of two kinds of 16S-23S rDNA internal spacer regions (ISRs), namely, long length ISRs of 837-844 base pair (bp) [n = six for urease-negative (UN) Campylobacter lari isolates, UN C. lari JCM2530(T), RM2100, 176, 293, 299 and 448] and short length ISRs of 679-725 bp [n = six for UN C. lari: n = 14 for urease-positive thermophilic Campylobacter (UPTC) isolates]. The analyses also indicated that the short length ISRs mainly lacked the 156 bp sequence from the nucleotide positions 122-277 bp in long length ISRs for UN C. lari JCM2530(T). The 156 bp sequences shared 94.9-96.8 % sequence similarity among six isolates. Surprisingly, atypical tRNA(Ala) gene segment (5' end 35 bp), which was extremely truncated, occurred within the 156 bp sequences in the long length ISRs, as an unexpected tRNA(Ala) pseudogene. An order of the intercistronic tRNA genes within the short nucleotide spacer of 5'-16S rDNA-tRNA(Ala)-tRNA(Ile)-23S rDNA-3' occurred in all the C. lari isolates examined.

  5. Computational model for armor penetration. Annual report No. 3, October 1980-April 1983

    SciTech Connect

    Erlich, D.C.; Seaman, L.; Cooper, T.; Caligiuri, R.D.; Curran, D.R.

    1987-10-01

    This is the first volume of a two-volume series comprising the third annual report for the program Computational Model for Armor Penetration. The objective of the program was to develop a phenomenologically sound material-disintegration model for computationally simulating armor penetration by projectile impact. The model would provide the capability to predict the ballistic limit and downrange fragment size and velocity distributions and would eventually be used by the DoD for armor and penetrator design. The materials studied in the program were 4340 steel and depleted uranium alloy, (DU) for the penetrators, and rolled homogeneous armor (RHA) for the target. This Volume reports on the experimental and analytical work performed during the third year to conclude the development of a computational model, SHEAR3, that describes the dominant material failure and fragmentation process (adiabatic shear banding) responsible for long-rod penetrator erosion and thick armor plate plugging and fragmentation. Volume 1 also describes application of SHEAR3 with the Lagrangian wave propagation code C-HEMP to computationally simulate penetration of armor plate by normally impacting long rods both near the ballistic limit and at higher velocities sufficient to produce significant back-of-the-armor fragmentation.

  6. The effects of exercise and body armor on cognitive function in healthy volunteers.

    PubMed

    Roberts, Aaron P J; Cole, Jon C

    2013-05-01

    Police officers routinely wear body armor to protect themselves against the threat posed by firearms and edged weapons, yet little is known of the cognitive effects of doing so. Two studies investigated the effects of exercise and body armor on working memory function in healthy volunteers. In study 1, male undergraduates were assigned to one of four groups: (i) brief exercise, (ii) brief exercise wearing body armor, (iii) extended exercise, and (iv) extended exercise wearing body armor. In study 2, university gym members were assigned to one of two groups: (i) wearing body armor and (ii) not wearing body armor. In both studies, heart rate and oral temperature were measured before, immediately after, and 5 minutes after exercise. The phonemic verbal fluency task and digits backward test were administered at the same time points. In both studies, a mixed analysis of variance revealed statistically significant changes to the cognitive functioning of participants. A change in cognitive strategy was observed, reflected by a decrease in executive function (switches) and an increase in nonexecutive function (cluster size). These data suggest that the cognitive effects of exercise and body armor may have profound implications for police officers' ability to make tactical decisions.

  7. Pretest Predictions of Long-Rod Interactions with Armor Technology Targets

    DTIC Science & Technology

    1994-04-01

    July 2 (1993). I 39. Y. Partom, "Ceramic Armor Resistance to Long-Rod Penetration (R.) and its Dependence on Projectile Velocity," Report No. IAT.R...I * AD - A281 384I Jllllll I PRETEST PREDICTIONS OF LONG-ROD INTERACTIONS WITH ARMOR TECHNOLOGY TARGETS DTIC I ELECTE Charles E. Anderson, Jr. JUL... Armor Technology Targets 6. AUTHR(S) j A 9-~-O Charles E. Anderson, Jr. DAvid L. Littlefield 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8

  8. US Army Armor Reference Data in Three Volumes. Volume III. Division 86 Organizations.

    DTIC Science & Technology

    1981-01-01

    AD-AIIS 857 ARMY ARMOR SCHOOL FORT KNOX KY F/G 19/ 3 US ARMY ARMOR REFERENCE DATA IN THREE VOLUMES. VOLUME 11. DrVi--ETC(U) 1981UNCLASSIFIED ST-17-1...VOL- 3 S@I-AOD-250 004 NL3illlllllllll mlllllllllllll mIIIIIIIIIIII IIIIIIIIIIIhI IIIIIIIIIIIhI IIIIIIIIIIIhI ST 17-1 -1 US ARMY ,~ ARMOR REFERENCE...DCUMNTATON AGEREAD INSTRUCTIONSREPRT OCUENATIN PGEBEFORE COMPLETING FORM 1. REPORT NUMBER 2. GOVT ACCESSION No. 3 . RECIPIENT’S CATALOG NUMBER 4. TITLE

  9. Analysis of Tile-Reinforced Composite Armor. Part 1; Advanced Modeling and Strength Analyses

    NASA Technical Reports Server (NTRS)

    Davila, C. G.; Chen, Tzi-Kang; Baker, D. J.

    1998-01-01

    The results of an analytical and experimental study of the structural response and strength of tile-reinforced components of the Composite Armored Vehicle are presented. The analyses are based on specialized finite element techniques that properly account for the effects of the interaction between the armor tiles, the surrounding elastomers, and the glass-epoxy sublaminates. To validate the analytical predictions, tests were conducted with panels subjected to three-point bending loads. The sequence of progressive failure events for the laminates is described. This paper describes the results of Part 1 of a study of the response and strength of tile-reinforced composite armor.

  10. Historical Review of the Correlation of Ballistic and Metallurgical Characteristics of Domestic Armor at Watertown Arsenal

    DTIC Science & Technology

    1945-12-07

    Blaw - Knox Company. A. Hurlich. 136. 1 A~ugust. Report No. B710/532. Armor--Development of a Yracture Test to Indicate the Degree of Hardening of Armor...Report No. M710/61, Metallurgical Examination of Section from 6" Experimental M4A3k2 Assault Turret Manufactured by Unien Steel Castings Div. of Blaw ... Knox Co. P. V. Riffin. 197. 24 July. Report No, E710/611. Armor Plate--Rolled, Investigation of Experimental Heat Treatments of 3/S Inch Thick

  11. Isosteric and nonisosteric base pairs in RNA motifs: molecular dynamics and bioinformatics study of the sarcin-ricin internal loop.

    PubMed

    Havrila, Marek; Réblová, Kamila; Zirbel, Craig L; Leontis, Neocles B; Šponer, Jiří

    2013-11-21

    The sarcin-ricin RNA motif (SR motif) is one of the most prominent recurrent RNA building blocks that occurs in many different RNA contexts and folds autonomously, that is, in a context-independent manner. In this study, we combined bioinformatics analysis with explicit-solvent molecular dynamics (MD) simulations to better understand the relation between the RNA sequence and the evolutionary patterns of the SR motif. A SHAPE probing experiment was also performed to confirm the fidelity of the MD simulations. We identified 57 instances of the SR motif in a nonredundant subset of the RNA X-ray structure database and analyzed their base pairing, base-phosphate, and backbone-backbone interactions. We extracted sequences aligned to these instances from large rRNA alignments to determine the frequency of occurrence for different sequence variants. We then used a simple scoring scheme based on isostericity to suggest 10 sequence variants with a highly variable expected degree of compatibility with the SR motif 3D structure. We carried out MD simulations of SR motifs with these base substitutions. Nonisosteric base substitutions led to unstable structures, but so did isosteric substitutions which were unable to make key base-phosphate interactions. The MD technique explains why some potentially isosteric SR motifs are not realized during evolution. We also found that the inability to form stable cWW geometry is an important factor in the case of the first base pair of the flexible region of the SR motif. A comparison of structural, bioinformatics, SHAPE probing, and MD simulation data reveals that explicit solvent MD simulations neatly reflect the viability of different sequence variants of the SR motif. Thus, MD simulations can efficiently complement bioinformatics tools in studies of conservation patterns of RNA motifs and provide atomistic insight into the role of their different signature interactions.

  12. International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons

    PubMed Central

    Olson, Nathan D.; Lund, Steven P.; Zook, Justin M.; Rojas-Cornejo, Fabiola; Beck, Brian; Foy, Carole; Huggett, Jim; Whale, Alexandra S.; Sui, Zhiwei; Baoutina, Anna; Dobeson, Michael; Partis, Lina; Morrow, Jayne B.

    2015-01-01

    This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA) sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1) identity of biologically conserved position, (2) ratio of 16S rRNA gene copies featuring identified variants, and (3) the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies. PMID:27077030

  13. Short Internal Sequences Involved in Replication and Virion Accumulation in a Subviral RNA of Turnip Crinkle Virus

    PubMed Central

    Sun, Xiaoping; Zhang, Guohua; Simon, Anne E.

    2005-01-01

    cis-acting sequences and structural elements in untranslated regions of viral genomes allow viral RNA-dependent RNA polymerases to correctly initiate and transcribe asymmetric levels of plus and minus strands during replication of plus-sense RNA viruses. Such elements include promoters, enhancers, and transcriptional repressors that may require interactions with distal RNA sequences for function. We previously determined that a non-sequence-specific hairpin (M1H) in the interior of a subviral RNA (satC) associated with Turnip crinkle virus is required for fitness and that its function might be to bridge flanking sequences (X. Sun and A. E. Simon, J. Virol. 77:7880-7889, 2003). To establish the importance of the flanking sequences in replication and satC-specific virion repression, segments on both sides of M1H were randomized and subjected to in vivo functional selection (in vivo SELEX). Analyses of winning (functional) sequences revealed three different conserved elements within the segments that could be specifically assigned roles in replication, virion repression, or both. One of these elements was also implicated in the molecular switch that releases the 3′ end from its interaction with the repressor hairpin H5, which is possibly involved in controlling the level of minus-strand synthesis. PMID:15596844

  14. The effect of body armor on performance, thermal stress, and exertion: a critical review.

    PubMed

    Larsen, Brianna; Netto, Kevin; Aisbett, Brad

    2011-11-01

    Armed forces worldwide utilize some form of body armor as part of their personal protective system. This is particularly essential in recent times because of the increased sophistication of weapons employed during modern warfare and the advent of unconventional combat methods (such as the increased use of improvised explosive devices). There is some evidence to show, however, that the usage of military body armor impairs physical performance. This review of the literature will focus on the effect of body armor on the performance of, and physiological and subjective responses during, military-style physical tasks. Because of the paucity of research investigating body armor, this review will also draw upon more generalized personal protective clothing and equipment literature from a range of physically demanding occupations (i.e., firefighting and other emergency services). The review will conclude with suggested directions for future research in this area.

  15. Use of body armor protection with fighting load impacts soldier performance and kinematics.

    PubMed

    Loverro, Kari L; Brown, Tyler N; Coyne, Megan E; Schiffman, Jeffrey M

    2015-01-01

    The purpose of this evaluation was to examine how increasing body armor protection with and without a fighting load impacted soldiers' performance and mobility. Thirteen male soldiers performed one performance (repeated 30-m rushing) and three mobility tasks (walk, walk over and walk under) with three different body armor configurations and an anterior fighting load. Increasing body armor protection, decreased soldier performance, as individual and total 30-m rush times were significantly longer with greater protection. While increasing body armor protection had no impact on mobility, i.e. significant effect on trunk and lower limb biomechanics, during the walk and walk over tasks, greater protection did significantly decrease maximum trunk flexion during the walk under task. Adding fighting load may negatively impact soldier mobility, as greater maximum trunk extension was evident during the walk and walk over tasks, and decreased maximum trunk flexion exhibited during the walk under task with the fighting load.

  16. Core Temperature and Surface Heat Flux During Exercise in Heat While Wearing Body Armor

    DTIC Science & Technology

    2015-10-26

    20 Physiological Responses (general) .................................................................. 20 Metabolism...21 Specific Physiological and Performance Measurements .................................. 21...This report describes the physiological responses of soldiers wearing combat clothing and body armor (BA) while treadmill walking in a climatic

  17. 30 CFR 77.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.700 Grounding metallic sheaths, armors... conductors shall be electrically continuous throughout and shall be grounded by methods approved by...

  18. A Discrete Element Model of Armor Glass Fragmentation and Comminution Failure Under Compression

    SciTech Connect

    Xu, Wei; Sun, Xin

    2016-02-15

    Because of its exceptional compressive resistance and crystal-clear appearance, lightweight glass has been traditionally used in transparent armor applications. However, due to its brittle nature, glass fails differently from ductile materials in the sense that glass fragmentation occurs instantly ahead of the projectile tip upon penetration. The effective residual strength of the armor glass then inevitably relies on the damaged glass strength within such comminuted zones with confinement from the surrounding intact materials. Physical understanding of damaged glass strength therefore becomes highly critical to the further development of armor designs. In the present study, a discrete element based modeling framework has been developed to understand and predict the evolution of compressive damages and residual strength of armor glasses. With the characteristic fragmentation and comminution failures explicitly resolved, their influences on the mechanical degradation of the loaded glass materials have been evaluated. The effects of essential loading conditions and material properties have also been investigated.

  19. Shock imprint and rolling direction influence upon the breaking tenacity for 2P armor steel

    NASA Astrophysics Data System (ADS)

    Zichil, V.; Coseru, A.; Schnakovszky, C.; Herghelegiu, E.; Radu, C.

    2016-08-01

    The state of art in present literature shows that the breaking tenacity of a material is influenced by the integrity of the structure. Since armors used in aviation and to protect military vehicles are frequently impact loaded, through the contact between armor sheet and projectiles, or other foreign bodies, the authors have proposed to study the dependence between the breaking tenacity of 2P armor steel depending on the direction of the rolling of the armor plate, of the geometry (spherical imprint, pyramidal and linear imprint) and the depth of the deformation that results after impact. Tests were conducted upon CT (ASTM E- 399) specimen type, using the critical factor of stress intensity during the state of planar strain.

  20. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-113 Pilot Paul Lockhart test drives an M-113 armored personnel carrier, part of emergency egress training during Terminal Countdown Demonstration Test activities. He is accompanied by several other crew members, seen at left, Mission Specialist Michael Lopez-Alegria and Commander James Wetherbee. The crew is preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10. The TCDT includes a simulated launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  1. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-113 Pilot Paul Lockhart stands inside an M-113 armored personnel carrier he is about to drive, part of emergency egress training during Terminal Countdown Demonstration Test activities. He and the rest of the crew are preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10. The TCDT includes a simulated launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  2. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-113 Mission Specialist John Herrington stands inside an M-113 armored personnel carrier that he is about to drive as part of emergency egress training during Terminal Countdown Demonstration Test activities. He and the rest of the crew are preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10. The TCDT includes a simulated launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  3. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-113 Mission Specialist John Herrington is at the wheel of an M-113 armored personnel carrier during emergency egress training at the pad. He is accompanied by (left) Mission Specialist Michael Lopez-Alegria and Commander James Wetherbee. The crew is preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10, by taking part in Terminal Countdown Demonstration Test activities. The TCDT includes a simulated launch countdown.. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  4. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-113 Mission Specialist Michael Lopez-Alegria concentrates on driving an M-113 armored personnel carrier during emergency egress training at the pad. He is accompanied by (far left) Mission Specialist John Herrington and Commander James Wetherbee. Behind Lopez-Alegria is Pilot Paul Lockhart. The crew is preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10, by taking part in Terminal Countdown Demonstration Test activities. The TCDT includes a simulated launch countdown.. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  5. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-113 Mission Commander James Wetherbee practices driving an M-113 armored personnel carrier, part of emergency egress training during Terminal Countdown Demonstration Test activities. He and the rest of the crew are preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10. The TCDT includes a launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  6. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - STS-113 Mission Commander James Wetherbee gets ready to drive an M-113 armored personnel carrier, part of emergency egress training during Terminal Countdown Demonstration Test activities. He and the rest of the crew are preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10. The TCDT includes a launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  7. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - STS-113 Mission Specialist Michael Lopez-Alegria is ready to begin a test drive behind the wheel of an M-113 armored personnel carrier during emergency egress training at the pad. He and the rest of the crew are preparing for the mission aboard Space Shuttle Endeavour, which is scheduled to launch Nov. 10, by taking part in Terminal Countdown Demonstration Test activities. The TCDT includes a simulated launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  8. STS-113 crew during M-113 armored personnel carrier training

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-113 crew pause for a photo after test drives in the M-113 armored personnel carrier behind them. From left are Mission Specialist Michael Lopez-Alegria, Pilot Paul Lockhart, Commander James Wetherbee and Mission Specialist John Herrington. Driving the M-113 is part of emergency egress training at the pad, one of the Terminal Countdown Demonstration Test activities in preparation for launch. The TCDT also includes a simulated launch countdown. The primary payloads on mission STS-113 are the first port truss segment, P1, and the Crew and Equipment Translation Aid (CETA) Cart B. Once delivered, the P1 truss will remain stowed until flight 12A.1 in 2003 when it will be attached to the central truss segment, S0, on the Space Station. Also onboard Space Shuttle Endeavour will be the Expedition 6 crew who will replace Expedition 5, returning to Earth after 4 months.

  9. Polythioether Particles Armored with Modifiable Graphene Oxide Nanosheets.

    PubMed

    Rodier, Bradley J; Mosher, Eric P; Burton, Spencer T; Matthews, Rachael; Pentzer, Emily

    2016-06-01

    Facile and scalable fabrication methods are attractive to prepare materials for diverse applications. Herein, a method is presented to prepare cross-linked polymeric nanoparticles with graphene oxide (GO) nanosheets covalently attached to the surface. Alkene-modified GO serves as a surfactant in a miniemulsion polymerization, and the alkene functionalities of GO exposed to the oil-phase are incorporated into the polymer particle through thiol-ene reactions, leaving the unreacted alkene functional groups of the other face of GO available for further functionalization. The surface of GO-armored polymer particles is then modified with a small molecule fluorophore or carboxylic acid functional groups that bind to Fe2 O3 and TiO2 nanoparticles. This methodology provides a facile route to preparing complex hybrid composite materials.

  10. Coated armor system and process for making the same

    DOEpatents

    Chu, Henry S.; Lillo, Thomas M.; McHugh, Kevin M.

    2010-11-23

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  11. Modeling gunshot bruises in soft body armor with an adaptive fuzzy system.

    PubMed

    Lee, Ian; Kosko, Bart; Anderson, W French

    2005-12-01

    Gunshots produce bruise patterns on persons who wear soft body armor when shot even though the armor stops the bullets. An adaptive fuzzy system modeled these bruise patterns based on the depth and width of the deformed armor given a projectile's mass and momentum. The fuzzy system used rules with sinc-shaped if-part fuzzy sets and was robust against random rule pruning: Median and mean test errors remained low even after removing up to one fifth of the rules. Handguns shot different caliber bullets at armor that had a 10%-ordnance gelatin backing. The gelatin blocks were tissue simulants. The gunshot data tuned the additive fuzzy function approximator. The fuzzy system's conditional variance V[Y/X = x] described the second-order uncertainty of the function approximation. Handguns with different barrel lengths shot bullets over a fixed distance at armor-clad gelatin blocks that we made with Type 250 A Ordnance Gelatin. The bullet-armor experiments found that a bullet's weight and momentum correlated with the depth of its impact on armor-clad gelatin (R2 = 0.881 and p-value < 0.001 for the null hypothesis that the regression line had zero slope). Related experiments on plumber's putty showed that highspeed baseball impacts compared well to bullet-armor impacts for large-caliber handguns. A baseball's momentum correlated with its impact depth in putty (R2 = 0.93 and p-value < 0.001). A bullet's momentum similarly correlated with its armor-impact in putty (R2 = 0.97 and p-value < 0.001). A Gujarati-Chow test showed that the two putty-impact regression lines had statistically indistinguishable slopes for p-value = 0.396. Baseball impact depths were comparable to bullet-armor impact depths: Getting shot with a .22 caliber bullet when wearing soft body armor resembles getting hit in the chest with a 40-mph baseball. Getting shot with a .45 caliber bullet resembles getting hit with a 90-mph baseball.

  12. Estimated radiactive and shock loading of fusion reactor armor

    SciTech Connect

    Swift, D C

    2008-11-25

    Inertial confinement fusion (ICF) is of interest as a source of neutrons for proliferation-resistant and high burn-up fission reactor designs. ICF is a transient process, each implosion leading to energy release over a short period, with a continuous series of ICF operations needed to drive the fission reactor. ICF yields energy in the form of MeV-range neutrons and ions, and thermal x-rays. These radiations, particularly the thermal x-rays, can deposit a pulse of energy in the wall of the ICF chamber, inducing loading by isochoric heating (i.e. at constant volume before the material can expand) or by ablation of material from the surface. The explosion of the hot ICF system, and the compression of any fill material in the chamber, may also result in direct mechanical loading by a blast wave (decaying shock) reaching the chamber wall. The chamber wall must be able to survive the repetitive loading events for long enough for the reactor to operate economically. It is thus necessary to understand the loading induced by ICF systems in possible chamber wall designs, and to predict the response and life time of the wall. Estimates are given for the loading induced in the wall armor of the fusion chamber caused by ablative thermal radiation from the fusion plasma and by the hydrodynamic shock. Taking a version of the LIFE design as an example, the ablation pressure was estimated to be {approx}0.6 GPa with an approximately exponential decay with time constant {approx}0.6 ns. Radiation hydrodynamics simulations suggested that ablation of the W armor should be negligible.

  13. Dragon Skin - How It Changed Body Armor Testing in the United States Army

    DTIC Science & Technology

    2015-09-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA JOINT APPLIED PROJECT DRAGON SKIN—HOW IT CHANGED BODY ARMOR TESTING IN THE...AND DATES COVERED Joint applied project 4. TITLE AND SUBTITLE DRAGON SKIN—HOW IT CHANGED BODY ARMOR TESTING IN THE UNITED STATES ARMY 5...Std. 239-18 ii THIS PAGE INTENTIONALLY LEFT BLANK iii Approved for public release; distribution is unlimited DRAGON SKIN—HOW IT

  14. Finite Element Analysis of Functionally Graded Material to Reduce Crazing in Transparent Armor

    DTIC Science & Technology

    2015-09-01

    based target on the shockwaves generated from an impactor. Most armor systems are comprised of a single material or a composite layup of several...the shockwaves generated from an impactor. Most armor systems are comprised of a single material or a composite layup of several materials. The...varying microstructure and particle density breaks up a shockwave more effectively than a homogenous target. The particles appear to effectively break

  15. Quantifying Bulk Plasticity and Predicting Transition Velocities for Armor Ceramics Using Hardness Indentation Tests

    DTIC Science & Technology

    2012-07-01

    calculations for various alumina materials . ..............................11  Table 3. Details of plasticity/TV calculations for various ceramic and...1 1. Introduction Many studies have shown that hardness is a very important property for ceramics used in armor applications (1–7). In general...enough to be useful in guiding the development of new, improved armor materials . Some studies have suggested that the ability of a ceramic material to

  16. AVVAM-1 (Armored Vehicle Vulnerability Analysis Model) and Tank Vulnerability Sensitivity Studies

    DTIC Science & Technology

    1973-01-01

    Ground , Maryland 0 Introduction I AVVAM-I ( Armored Vehicle Vulnerability Analysis Model -first version) is a conceptuil model-and associateS digital... measure of the ballistic shielding provided by a tank component. *The higher this value the harder it is for a spall fragment to perforate the component...in vulnerability to ballistic damage from behind-the- armor frag- ments and in the ability of noncritical components to provide ballistic shielding for

  17. Advancements in Steel for Weight Reduction of P900 Armor Plate

    DTIC Science & Technology

    2008-12-01

    were investigated as alternatives to MIL-PRF- 32269 steel alloys for application in P900 perforated armor currently used for Army ground combat...ADVANCEMENTS IN STEEL FOR WEIGHT REDUCTION OF P900 ARMOR PLATE R. A. Howell*, J. S. Montgomery Survivability Materials Branch Army Research Lab...Aberdeen Proving Grounds , MD 21001 D.C. Van Aken Missouri University for Science and Technology Rolla, MO 65401 ABSTRACT Ballistic tests

  18. SiC Armor Tiles via Magnetic Compaction and Pressureless Sintering

    DTIC Science & Technology

    2008-01-27

    Ceramatec, ORNL ,ARMY and UDRI Unclassified 7Cocoa Beach 2008 What is Dynamic Magnetic Compaction? Dynamic Kinetic process High compaction pressure for sub...1Cocoa Beach 2008 SiC Armor Tiles via Magnetic Compaction and Pressureless Sintering B. Chelluri, and E. A. Knoth, IAP Research, Inc. L. P. Franks...TITLE AND SUBTITLE SiC Armor Tiles via Magnetic Compaction and Pressureless Sintering 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  19. MM&T Manufacturing Methods for Gradient Furnace Processing of Ceramic Armor and Structural Ceramics

    DTIC Science & Technology

    1980-08-01

    designated by other authorized documents. Mention of any trade names or manufacturers in this report shall not be construed as advertising nor as an...single crystal materials opens up many possi- bilities for new applications of ceramics, such as in the case of trans- parent armor, lasers, and...possibilities for new applications of ceramics such as in the case of transparent armor, lasers, and laser windows. With the increase in size of single

  20. Evaluation of the Combat Vehicle Command and Control System: Operational Effectiveness of an Armor Battalion

    DTIC Science & Technology

    1994-06-01

    Armor Officer Advance 22 46.8 27 56.3 Course ( AOAC ) Armor Officer Basic 46 97.9 48 100 Course (AOBC) NCO!Enl isted Advanced NCO Course 3 3.3 17 17.7...Tank-Automotive Command (TACOM), Subject: Combat Vehicle Command and Control (CVCC) Programs, 22 March 1989. The CVCC research program investigates...18 Support Personnel ................... 19 Test Facilities . . . . . . . . . . . . . . . ..... 22 Training and Test

  1. The Combat System Design and Test Criteria for Iguana TM Armored Vehicles.

    DTIC Science & Technology

    1999-06-01

    stabilization, improved ride and agility, and reduced acoustic/IR signatures. The Iguana (trademark), a tracked vehicle concept based on a recently patented...hybrid armored vehicle drive systems. This thesis presents a combat system integration process for an Iguana (trademark) based armored vehicle. It lays...for night vision sensors. The U.S. Army Night Vision & Electronic Sensors Directorate’s ELIR92 and ACQUIRE computer programs are used to establish feasible Iguana (trademark) thermal night vision device performance requirements.

  2. A Review and Annotated Bibliography of Literature Relevant to Armor Skill Retention

    DTIC Science & Technology

    1993-02-01

    AD-A263 407 DTIC ELECTE APR 27 1993 Research Product 93-03 C A Review and Annotated Bibliography of Literature Relevant to Armor Skill Retention...TYPE AND DATES COVERED 1993, February Final Jan 92 - Nov 92 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS A Review and Annotated Bibliography of Literature ...has also been made available to armor unit trainers. EDGAR M. JOHNSON Acting Director v A REVIEW AND ANNOTATED BIBLIOGRAPHY OF LITERATURE RELEVANT TO

  3. Improvement of Armor Stone Performance for Protection of Great Lakes Coastal Navigation Areas

    NASA Astrophysics Data System (ADS)

    Zakikhani, M.; Harrelson, D. W.

    2008-12-01

    Evaluating long-term performance and deterioration of armor stones are essential for maritime structures to protect harbors or navigable areas. Armor rocks are impacted by the natural elements such as seasonal weather, and repeated cycles of temperature (e.g., flowing water, wetting and drying, wave action, freeze and thaw, etc.). The rock's behavior in the field may vary greatly from the laboratory test results. The design process for the determination of armor stone sizes is complex and various factors must be considered in order to fully understand how the design parameters have an indirect effect on stone performance. Numerous investigators have studied to develop relationships for the minimum stable weight of a rubble-mound armor unit for given wave conditions. The main objective of this study has been to evaluate major factors affecting the armor stone durability. The effects of scaling on the test results of various samples of rock types used in Great Lakes coastal projects have been investigated. To consider the combined effects of environmental stresses on armor stone, testing have been done to evaluate the performance of stone subjected to both freezing and thawing and wetting and drying. The stone quarries and sites were evaluated and sampled to determine the stone sources, and their surrounding environments. Long-term performance or deterioration of armor stones have been quantitatively monitored and characterized by the changes in dimensions measured. A degradation numerical model has been developed that relates the laboratory test results to the modification of the mass distribution and reduction at the project site. The paper presentation will describe and illustrate the latest results and developed tools for the armor stone evaluations. We will introduce new approaches that may be used to evaluate the quality and durability with reference to breakage and integrity.

  4. Predation's role in repeated phenotypic and genetic divergence of armor in threespine stickleback.

    PubMed

    Marchinko, Kerry B

    2009-01-01

    Predator-driven divergent selection may cause differentiation in defensive armor in threespine stickleback: (1) predatory fish and birds favor robust armor, whereas (2) predaceous aquatic insects favor armor reduction. Although (1) is well established, no direct experimental evidence exists for (2). I examined the phenotypic and genetic consequences of insect predation using F(2) families from crosses between freshwater and marine stickleback populations. I measured selection on body size, and size-adjusted spine (dorsal and pelvic) and pelvic girdle length, by splitting juvenile F(2) families between control and insect predation treatments, set in pond enclosures. I also examined the effect of insect predation on Ectodysplasin (Eda), a gene physically linked to quantitative trait loci for lateral plate number, spine length, and body shape. Insect predation resulted in: (1) significant selection for larger juvenile size, and shorter dorsal spine and pelvic girdle length, (2) higher mortality of individuals missing the pelvic girdle, and (3) selection in favor of the low armor Eda allele. Predatory insects favor less stickleback armor, likely contributing to the widespread reduction of armor in freshwater populations. Because size strongly influences mate choice, predator-driven divergent selection on size may play a substantial role in byproduct reproductive isolation and speciation in threespine stickleback.

  5. The UAH/NSSTC Advanced Radar for Meteorological and Operational Research (ARMOR)

    NASA Technical Reports Server (NTRS)

    Petersen, Walter A.; Knupp, Kevin; Carey, Lawrence D.; Phillips, Dustin; Deierling, Wiebke; Gatlin, Patrick

    2009-01-01

    The past four years have seen a marked enhancement in meteorological-radar infrastructure and radar-research capability at the University of Alabama-Huntsville (UAH) and National Space Science and Technology Center (NSSTC; a collaborative center supported by UAH, NASA-MSFC and USRA). This enhancement is due in part to the development of the ARMOR C-band dual-polarimetric radar facility (amongst other mobile radar facilities also discussed in this conference). The ARMOR radar, located at Huntsville International Airport, originated as a unique collaboration between university, government and broadcast meteorologists (the very first of its kind relative to concurrent operational, research and broadcast applications of dual-polarimetry). Contributions from each of these entities resulted in the upgrade of a surplus National Weather Service WSR-74C radar to a research-grade C-band polarimetric radar. The initial upgrade of the radar took place in late 2004 with WHNT-TV purchase and installation of a SIGMET (now Vaisala) Antenna Mounted Receiver (AMR), RVP8/RCP8 radar processor/antenna controller, new radome, and a new dual-polarimetric antenna feed. The AMR enabled simultaneous transmit and receive (STSR) capability and hence collection of dual-polarimetric moments. During the initial part of the AMR upgrade the original WSR74C antenna reflector and 250 kW magnetron-transmitter were used. In early 2005, a new 350 kW magnetron transmitter was purchased from Baron Services and installed. In October of 2006 a new high performance parabolic antenna and dual-pol feed (Seavey) were installed together with a new Orbit pedestal. ARMOR Radar control and data delivery are facilitated through the use of T-1 lines that run from the airport to both NSSTC and WHNT-TV in Huntsville. Under current operating protocols radar scanning and product development are completed at NSSTC, though meteorologists at WHNT-TV can also control the radar if desired. In its default scanning

  6. Characterization of vibration and noise exposure in Canadian Forces armored vehicles

    NASA Astrophysics Data System (ADS)

    Nakashima, Ann M.; Borland, Matthew J.; Abel, Sharon M.

    2005-09-01

    A study to characterize the vibration and noise exposure in several Canadian Forces (CF) armored vehicles is in progress. Measurements of whole-body vibration and ambient noise levels are being made in the LAV III, Bison, Coyote, and M113 vehicles at three different positions: driver, crew commander, and passenger bench (or navigator seat in the case of the Coyote). The measurements are being made while the vehicles are idling, driven over rough terrain, and driven at a high speed on paved highways. There are several standards that provide guidance on the measurement and assessment of whole-body vibration, but they are difficult to implement in practice, particularly in adverse environments. The whole-body vibration measurements in this study are particularly difficult to interpret in the case of the crew commander, who often stands on the seat, and the passenger, who is seated but unrestrained by a seatbelt. The preliminary results-suggest, that according to the International Organization for Standardization guidelines (ISO 2631-1:1997), there may be potential health risks for the driver and passenger after driving on rough terrain for less than 10 min. Noise levels were as high as 100 dBA during high-speed highway driving.

  7. Multiphysics Modeling and Simulations of Mil A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding Process

    DTIC Science & Technology

    2013-05-23

    Multiphysics Modeling and Simulations of Mil A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding Process M. Grujicic, S. Ramaswami, J.S...hardness armor martensitic steel . The model consists of five distinct modules, each covering a specific aspect of the GMAW process, i.e., (a) dynamics...FZ, and the adjacent heat-affected zone, HAZ) of a prototypical high-hardness armor-grade martensitic steel MIL A46100 (Ref 1). It is hoped that the

  8. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of MIL A46100 Armor-Grade Steel: A Computational Investigation

    DTIC Science & Technology

    2014-06-12

    distribution is unlimited. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of Mil A46100 Armor- Grade Steel : A Computational Investigation The views...Welds of Mil A46100 Armor- Grade Steel : A Computational Investigation Report Title In our recent work, a multi-physics computational model for the...utility of the upgraded GMAW process model, it is next applied to the case of butt-welding of a prototypical high-hardness armor- grade martensitic steel

  9. Intrageneric structure of the genus Gluconobacter analyzed by the 16S rRNA gene and 16S-23S rRNA gene internal transcribed spacer sequences.

    PubMed

    Takahashi, Mai; Yukphan, Pattaraporn; Yamada, Yuzo; Suzuki, Ken-ichiro; Sakane, Takeshi; Nakagawa, Yasuyoshi

    2006-06-01

    Forty-nine strains belonging to the genus Gluconobacter were re-examined with respect to their species identification based on the sequences of the 16S rDNA and 16S-23S rDNA internal transcribed spacer regions (ITS). A phylogenetic tree constructed from the 16S rDNA sequences indicated the presence of five clusters corresponding, respectively, to the major five species of the genus Gluconobacter, namely G. albidus, G. cerinus, G. frateurii, G. oxydans (type species), and G. thailandicus. The type strain of G. asaii, NBRC 3276T (T=type strain) was included in the G. cerinus cluster, which is consistent with the report that G. asaii is a junior subjective synonym of G. cerinus. Existence of the G. albidus, G. cerinus, G. frateurii, G. oxydans, and G. thailandicus clusters was also recognized by the ITS sequence analysis. Both sequence analyses revealed that the G. cerinus and G. frateurii clusters were heterogeneous. The G. cerinus cluster comprised three strains of G. cerinus and one strain of G. frateurii, while the G. frateurii cluster included ten strains of G. frateurii, three of G. cerinus, and eleven of G. oxydans. These results suggest that phenotypic differences among Gluconobacter species are ambiguous and the species definition must be re-evaluated. The 16S rDNA and ITS sequences determined in this study are valuable for the identification and phylogenetic analysis of Gluconobacter species.

  10. Differentiation of acetic acid bacteria based on sequence analysis of 16S-23S rRNA gene internal transcribed spacer sequences.

    PubMed

    González, Angel; Mas, Albert

    2011-06-30

    The 16S-23S gene internal transcribed spacer sequence of sixty-four strains belonging to different acetic acid bacteria genera were analyzed, and phylogenetic trees were generated for each genera. The topologies of the different trees were in accordance with the 16S rRNA gene trees, although the similarity percentages obtained between the species was shown to be much lower. These values suggest the usefulness of including the 16S-23S gene internal transcribed spacer region as a part of the polyphasic approach required for the further classification of acetic acid bacteria. Furthermore, the region could be a good target for primer and probe design. It has also been validated for use in the identification of unknown samples of this bacterial group from wine vinegar and fruit condiments.

  11. International Symposium on Positive Strand RNA Viruses (2nd) Held in Vienna, Austria on June 26-30, 1989. Abstracts

    DTIC Science & Technology

    1989-07-01

    sylvatic cycle of dengue virus exists. 24 P 25 P 26 INFECTIOUS THEILER’SVIRUS cONA CLONEiSSTUDIES OF RAPID MOLECULAR EVOLUTION OF WILD TYPE 3 INTRATYPIC... rapid evolution took ~ace between sequential isolates and amino acid substitutions were seen at the known antigenic sites. P 27 P 28 HOMOLOGOUS PCTY...ELEMENTS INVOLVED IN REPLICATION OF VARIABILITY AND EVOLUTION OF FIELD ISOLATES OF PLANT ALFALFA MOSAIC VIRUS RNAS. RNA VIRUSES.A.C.an der Kuyl

  12. Structural properties of mobile armors formed at different flow strengths in gravel-bed rivers

    NASA Astrophysics Data System (ADS)

    Powell, D. Mark; Ockelford, Annie; Rice, Stephen P.; Hillier, John K.; Nguyen, Thao; Reid, Ian; Tate, Nicholas J.; Ackerley, David

    2016-08-01

    Differences in the structure of mobile armors formed at three different flow strengths have been investigated in a laboratory flume. The temporal evolution of the bed surfaces and the properties of the final beds were compared using metrics of surface grain size, microtopography, and bed organization at both grain and mesoscales. Measurements of the bed condition were obtained on nine occasions during each experiment to describe the temporal evolution of the beds. Structured mobile armors formed quickly in each experiment. At the grain scale (1-45 mm; 9 ≤ Ds50 ≤ 17 mm where Ds50 is the median surface particle size), surface complexity decreased and bed roughness increased in response to surface coarsening and the development of the mobile armor. Particles comprising the armor also became flow aligned and developed imbrication. At a larger scale (100-200 mm), the surface developed a mesoscale topography through the development of bed patches with lower and higher elevations. Metrics of mobile armor structure showed remarkable consistency over prolonged periods of near-constant transport, demonstrating for the first time that actively transporting surfaces maintain an equilibrium bed structure. Bed structuring was least developed in the experiments conducted at the lowest flow strength. However, little difference was observed in the structural metrics of the mobile armors generated at higher flows. Although the range of transport rates studied was limited, the results suggest that the structure of mobile armors is insensitive to the formative transport rate except when rates are low (τ* ≈ 0.03 where τ* is the dimensionless shear stress).

  13. Viscoelastic shock wave in ballistic gelatin behind soft body armor.

    PubMed

    Liu, Li; Fan, Yurun; Li, Wei

    2014-06-01

    Ballistic gelatins are widely used as a surrogate of biological tissue in blunt trauma tests. Non-penetration impact tests of handgun bullets on the 10wt% ballistic gelatin block behind soft armor were carried out in which a high-speed camera recorded the crater׳s movement and pressure sensors imbedded in the gelatin block recorded the pressure waves at different locations. The observed shock wave attenuation indicates the necessity of considering the gelatin׳s viscoelasticity. A three-element viscoelastic constitutive model was adopted, in which the relevant parameters were obtained via fitting the damping free oscillations at the beginning of the creep-mode of rheological measurement, and by examining the data of published split Hopkinson pressure bar (SHPB) experiments. The viscoelastic model is determined by a retardation time of 5.5×10(-5)s for high oscillation frequencies and a stress relaxation time of 2.0-4.5×10(-7)s for shock wave attenuation. Using the characteristic-line method and the spherical wave assumption, the propagation of impact pressure wave front and the subsequent unloading profile can be simulated using the experimental velocity boundary condition. The established viscoelastic model considerably improves the prediction of shock wave attenuation in the ballistic gelatin.

  14. Armor and anesthesia: exposure, feeling, and the soldier's body.

    PubMed

    MacLeish, Kenneth T

    2012-03-01

    For many civilians, the high-tech weapons, armor, and military medicine with which U.S. soldiers are equipped present an image of lethal capacity and physical invulnerability. But, as this article explores, soldiers themselves just as often associate the life-sustaining technology of modern warfare with feelings that range from a pragmatic ambivalence about exposure to harm all the way to profoundly unsettling vulnerability. This article, based on fieldwork among soldiers and military families at the U.S. Army's Ft. Hood, examines sensory and affective dimensions of soldiers' intimate bodily relationships with the technologies that alternately or even simultaneously keep them alive and expose them to harm. I argue that modern military discipline and technology conspire to cultivate soldiers as highly durable, capable, unfeeling, interchangeable bodies, or what might be called, after Susan Buck-Morss (1992), anesthetic subjects. But for soldiers themselves, their training, combat environment, protective gear, and weapons are a rich font of both emotional and bodily feeling that exists in complex tension with the also deeply felt military imperative to carry on in the face of extreme discomfort and danger.

  15. Reverse Evolution of Armor Plates in the Threespine Stickleback

    USGS Publications Warehouse

    Kitano, J.; Bolnick, D.I.; Beauchamp, D.A.; Mazur, M.M.; Mori, S.; Nakano, T.; Peichel, C.L.

    2008-01-01

    Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not??only for the understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem [1-8]. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of "reverse evolution," [9] because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks [10]. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus [11]. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime. ?? 2008 Elsevier Ltd. All rights reserved.

  16. Armored kinorhynch-like scalidophoran animals from the early Cambrian

    PubMed Central

    Zhang, Huaqiao; Xiao, Shuhai; Liu, Yunhuan; Yuan, Xunlai; Wan, Bin; Muscente, A. D.; Shao, Tiequan; Gong, Hao; Cao, Guohua

    2015-01-01

    Morphology-based phylogenetic analyses support the monophyly of the Scalidophora (Kinorhyncha, Loricifera, Priapulida) and Nematoida (Nematoda, Nematomorpha), together constituting the monophyletic Cycloneuralia that is the sister group of the Panarthropoda. Kinorhynchs are unique among living cycloneuralians in having a segmented body with repeated cuticular plates, longitudinal muscles, dorsoventral muscles, and ganglia. Molecular clock estimates suggest that kinorhynchs may have diverged in the Ediacaran Period. Remarkably, no kinorhynch fossils have been discovered, in sharp contrast to priapulids and loriciferans that are represented by numerous Cambrian fossils. Here we describe several early Cambrian (~535 million years old) kinorhynch-like fossils, including the new species Eokinorhynchus rarus and two unnamed but related forms. E. rarus has characteristic scalidophoran features, including an introvert with pentaradially arranged hollow scalids. Its trunk bears at least 20 annuli each consisting of numerous small rectangular plates, and is armored with five pairs of large and bilaterally placed sclerites. Its trunk annuli are reminiscent of the epidermis segments of kinorhynchs. A phylogenetic analysis resolves E. rarus as a stem-group kinorhynch. Thus, the fossil record confirms that all three scalidophoran phyla diverged no later than the Cambrian Period. PMID:26610151

  17. Armored kinorhynch-like scalidophoran animals from the early Cambrian.

    PubMed

    Zhang, Huaqiao; Xiao, Shuhai; Liu, Yunhuan; Yuan, Xunlai; Wan, Bin; Muscente, A D; Shao, Tiequan; Gong, Hao; Cao, Guohua

    2015-11-26

    Morphology-based phylogenetic analyses support the monophyly of the Scalidophora (Kinorhyncha, Loricifera, Priapulida) and Nematoida (Nematoda, Nematomorpha), together constituting the monophyletic Cycloneuralia that is the sister group of the Panarthropoda. Kinorhynchs are unique among living cycloneuralians in having a segmented body with repeated cuticular plates, longitudinal muscles, dorsoventral muscles, and ganglia. Molecular clock estimates suggest that kinorhynchs may have diverged in the Ediacaran Period. Remarkably, no kinorhynch fossils have been discovered, in sharp contrast to priapulids and loriciferans that are represented by numerous Cambrian fossils. Here we describe several early Cambrian (~535 million years old) kinorhynch-like fossils, including the new species Eokinorhynchus rarus and two unnamed but related forms. E. rarus has characteristic scalidophoran features, including an introvert with pentaradially arranged hollow scalids. Its trunk bears at least 20 annuli each consisting of numerous small rectangular plates, and is armored with five pairs of large and bilaterally placed sclerites. Its trunk annuli are reminiscent of the epidermis segments of kinorhynchs. A phylogenetic analysis resolves E. rarus as a stem-group kinorhynch. Thus, the fossil record confirms that all three scalidophoran phyla diverged no later than the Cambrian Period.

  18. Association between back, neck, and upper extremity musculoskeletal pain and the individual body armor.

    PubMed

    Konitzer, Lisa N; Fargo, Matthew V; Brininger, Teresa L; Lim Reed, Mary

    2008-01-01

    The purpose of this study was to investigate the relationship between back, neck, and upper extremity (UE) musculoskeletal pain and the wear of individual body armor, physical training (PT), and work tasks. We conducted a cross-sectional randomized-survey design in which 1,187 surveys were distributed to U.S. Soldiers in Iraq; 863 were completed. The survey was a three-page questionnaire covering demographics, body armor wear, PT, and reports of neck, back, and UE musculoskeletal pain before and during deployment. The results of the survey revealed a substantial increase in the incidence of back, neck, and UE pain during deployment, and approximately twice as many Soldiers attributed their musculoskeletal pain to wearing body armor than to job tasks and PT. In addition, there was a significant positive correlation between Soldiers who wore the body armor for four hours or more a day and self-reported musculoskeletal complaints. These results demonstrate a need to consider the potential adverse effects of individual body armor on combat Soldiers.

  19. Armor-piercing bullet: 3-T MRI findings and identification by a ferromagnetic detection system.

    PubMed

    Karacozoff, Alexandra M; Pekmezci, Murat; Shellock, Frank G

    2013-03-01

    The objective of this project was to evaluate magnetic resonance imaging (MRI) issues at 3 T for an armor-piercing bullet and to determine if this item could be identified using a ferromagnetic detection system. An armor-piercing bullet (.30 caliber, 7.62 × 39, copper-jacketed round, steel core; Norinco) underwent evaluation for magnetic field interactions, heating, and artifacts using standardized techniques. Heating was assessed with the bullet in a gelled-saline-filled phantom with MRI performed using a transmit/receive radio frequency body coil at a whole-body-averaged specific absorption rate of 2.9 W/kg for 15 minutes. Artifacts were characterized using T1-weighted spin echo and gradient echo pulse sequences. In addition, a special ferromagnetic detection system (Ferroguard Screener; Metrasens, Lisle, Illinois) was used in an attempt to identify this armor-piercing bullet. The findings indicated that the armor-piercing bullet showed substantial magnetic field interactions. Heating was not excessive. Artifacts were large and may create diagnostic problems if the area of interest is close to this bullet. The ferromagnetic detection system yielded a positive result. We concluded that this armor-piercing bullet is MR unsafe. Importantly, this ballistic item was identified using the particular ferromagnetic detection system utilized in this investigation, which has important implications for MRI screening and patient safety.

  20. The addition of body armor diminishes dynamic postural stability in military soldiers.

    PubMed

    Sell, Timothy C; Pederson, Jonathan J; Abt, John P; Nagai, Takashi; Deluzio, Jennifer; Wirt, Michael D; McCord, Larry J; Lephart, Scott M

    2013-01-01

    Poor postural stability has been identified as a risk factor for lower extremity musculoskeletal injury. The additional weight of body armor carried by Soldiers alters static postural stability and may predispose Soldiers to lower extremity musculoskeletal injuries. However, static postural stability tasks poorly replicate the dynamic military environment, which places considerable stress on the postural control system during tactical training and combat. Therefore, the purpose of this study was to examine the effects of body armor on dynamic postural stability during single-leg jump landings. Thirty-six 101st Airborne Division (Air Assault) Soldiers performed single-leg jump landings in the anterior direction with and without wearing body armor. The dynamic postural stability index and the individual stability indices (medial-lateral stability index, anterior-posterior stability index, and vertical stability index) were calculated for each condition. Paired sample t-tests were performed to determine differences between conditions. Significant differences existed for the medial-lateral stability index, anterior-posterior stability index, vertical stability index, and dynamic postural stability index (p < 0.05). The addition of body armor resulted in diminished dynamic postural stability, which may result in increased lower extremity injuries. Training programs should address the altered dynamic postural stability while wearing body armor in attempts to promote adaptations that will result in safer performance during dynamic tasks.

  1. ALON optical ceramic transparencies for window, dome, and transparent armor applications

    NASA Astrophysics Data System (ADS)

    Goldman, Lee M.; Twedt, Rich; Balasubramanian, Sreeram; Sastri, Suri

    2011-06-01

    Surmet continues to invest in and expand its manufacturing capability for ALON® Optical Ceramic, as the market demand for this material increases. The biggest demand and opportunity continues to be in the area of transparent armor, however, the market for sensor domes and windows, made from ALON, continues to grow at an impressive rate as well. ALON® Transparent Armor's unsurpassed ballistic performance, combined with the robustness of ALON's manufacturing process and reproducibly high material quality make ALON the leading candidate for many future armor systems. Recent results for ALON armor windows will be presented. Advances being made in Surmet's production capability to support the very large quantities of material required by the transparent armor market also benefit the sensor market. Improvements in quality, quantity and manufacturability of ALON material, combined with improvements being made in optical quality, ensure a robust supply of high quality material for high volume window and dome applications. Recent advancement in ALON® window and dome blanks, as well as in optical fabrication will be presented.

  2. Broadly reactive nested reverse transcription-PCR using an internal RNA standard control for detection of noroviruses in stool samples.

    PubMed

    Medici, Maria Cristina; Martinelli, Monica; Ruggeri, Franco Maria; Abelli, Laura Anna; Bosco, Simona; Arcangeletti, Maria Cristina; Pinardi, Federica; De Conto, Flora; Calderaro, Adriana; Chezzi, Carlo; Dettori, Giuseppe

    2005-08-01

    We developed a nested reverse transcription-PCR (nRT-PCR) for the detection of noroviruses in stools, using random primers for RT, the JV12/JV13 primer pair in the first round of nPCR, and a set of nine inner primers for the second, comprising the reverse sequences of primers SR46, SR48, SR50, and SR52, and five novel oligonucleotide sequences (113-1, 113-2, 115-1, 115-2, and 115-3). The specificity of the nRT-PCR was confirmed by testing 61 stools containing enteric viruses other than noroviruses. In comparative assays on either stools or RNA dilutions from two genogroup I and three genogroup II (GII) norovirus-positive samples, nRT-PCR was always at least as sensitive as RT-PCR and Southern hybridization. With some of the samples tested, the increase in sensitivity was 10-fold or higher. For GII viruses, the detectable range of nRT-PCR was estimated to be 8.4 x 10(4) to 2 RNA viral particles. When used on 85 stools from pediatric patients with acute gastroenteritis negative for viruses by electron microscopy and cell culture, the nRT-PCR detected norovirus in 19 samples (22.3%), while it failed to detect one reference RT-PCR-positive sample containing a Desert Shield strain. Sixteen of the 19 nRT-PCR-positive samples gave concordant results with reference RT-PCR and Southern hybridization, and all with sequence analysis. Partial sequencing of the polymerase region revealed that from January to April 2000 all GII strains except two (Rotterdam- and Leeds-like viruses) formed a tight cluster related to Hawaii virus. The nRT-PCR described could prove suitable for large epidemiological studies and for specialized clinical laboratories performing routine molecular testing.

  3. Broadly Reactive Nested Reverse Transcription-PCR Using an Internal RNA Standard Control for Detection of Noroviruses in Stool Samples

    PubMed Central

    Medici, Maria Cristina; Martinelli, Monica; Ruggeri, Franco Maria; Abelli, Laura Anna; Bosco, Simona; Arcangeletti, Maria Cristina; Pinardi, Federica; De Conto, Flora; Calderaro, Adriana; Chezzi, Carlo; Dettori, Giuseppe

    2005-01-01

    We developed a nested reverse transcription-PCR (nRT-PCR) for the detection of noroviruses in stools, using random primers for RT, the JV12/JV13 primer pair in the first round of nPCR, and a set of nine inner primers for the second, comprising the reverse sequences of primers SR46, SR48, SR50, and SR52, and five novel oligonucleotide sequences (113-1, 113-2, 115-1, 115-2, and 115-3). The specificity of the nRT-PCR was confirmed by testing 61 stools containing enteric viruses other than noroviruses. In comparative assays on either stools or RNA dilutions from two genogroup I and three genogroup II (GII) norovirus-positive samples, nRT-PCR was always at least as sensitive as RT-PCR and Southern hybridization. With some of the samples tested, the increase in sensitivity was 10-fold or higher. For GII viruses, the detectable range of nRT-PCR was estimated to be 8.4 × 104 to 2 RNA viral particles. When used on 85 stools from pediatric patients with acute gastroenteritis negative for viruses by electron microscopy and cell culture, the nRT-PCR detected norovirus in 19 samples (22.3%), while it failed to detect one reference RT-PCR-positive sample containing a Desert Shield strain. Sixteen of the 19 nRT-PCR-positive samples gave concordant results with reference RT-PCR and Southern hybridization, and all with sequence analysis. Partial sequencing of the polymerase region revealed that from January to April 2000 all GII strains except two (Rotterdam- and Leeds-like viruses) formed a tight cluster related to Hawaii virus. The nRT-PCR described could prove suitable for large epidemiological studies and for specialized clinical laboratories performing routine molecular testing. PMID:16081909

  4. Overcoming cellular barriers for RNA therapeutics.

    PubMed

    Dowdy, Steven F

    2017-03-01

    RNA-based therapeutics, such as small-interfering (siRNAs), microRNAs (miRNAs), antisense oligonucleotides (ASOs), aptamers, synthetic mRNAs and CRISPR-Cas9, have great potential to target a large part of the currently undruggable genes and gene products and to generate entirely new therapeutic paradigms in disease, ranging from cancer to pandemic influenza to Alzheimer's disease. However, for these RNA modalities to reach their full potential, they first need to overcome a billion years of evolutionary defenses that have kept RNAs on the outside of cells from invading the inside of cells. Overcoming the lipid bilayer to deliver RNA into cells has remained the major problem to solve for widespread development of RNA therapeutics, but recent chemistry advances have begun to penetrate this evolutionary armor.

  5. An RNA molecular switch: Intrinsic flexibility of 23S rRNA Helices 40 and 68 5’-UAA/5’-GAN internal loops studied by molecular dynamics methods

    PubMed Central

    Réblová, Kamila; Střelcová, Zora; Kulhánek, Petr; Beššeová, Ivana; Mathews, David H.; Nostrand, Keith Van; Yildirim, Ilyas; Turner, Douglas H.; Šponer, Jiří

    2010-01-01

    Functional RNA molecules such as ribosomal RNAs frequently contain highly conserved internal loops with a 5’-UAA/5’-GAN (UAA/GAN) consensus sequence. The UAA/GAN internal loops adopt distinctive structure inconsistent with secondary structure predictions. The structure has a narrow major groove and forms a trans Hoogsteen/Sugar edge (tHS) A/G base pair followed by an unpaired stacked adenine, a trans Watson-Crick/Hoogsteen (tWH) U/A base pair and finally by a bulged nucleotide (N). The structure is further stabilized by a three-adenine stack and base-phosphate interaction. In the ribosome, the UAA/GAN internal loops are involved in extensive tertiary contacts, mainly as donors of A-minor interactions. Further, this sequence can adopt an alternative 2D/3D pattern stabilized by a four-adenine stack involved in a smaller number of tertiary interactions. The solution structure of an isolated UAA/GAA internal loop shows substantially rearranged base pairing with three consecutive non-Watson-Crick base pairs. Its A/U base pair adopts an incomplete cis Watson-Crick/Sugar edge (cWS) A/U conformation instead of the expected Watson-Crick arrangement. We performed 3.1 µs of explicit solvent molecular dynamics (MD) simulations of the X-ray and NMR UAA/GAN structures, supplemented by MM-PBSA free energy calculations, locally enhanced sampling (LES) runs, targeted MD (TMD) and nudged elastic band (NEB) analysis. We compared parm99 and parmbsc0 force fields and net-neutralizing Na+ vs. excess salt KCl ion environments. Both force fields provide a similar description of the simulated structures, with the parmbsc0 leading to modest narrowing of the major groove. The excess salt simulations also cause a similar effect. While the NMR structure is entirely stable in simulations, the simulated X-ray structure shows considerable widening of the major groove, loss of base-phosphate interaction and other instabilities. The alternative X-ray geometry even undergoes conformational

  6. A new PCR primer for the identification of Paracoccidioides brasiliensis based on rRNA sequences coding the internal transcribed spacers (ITS) and 5 x 8S regions.

    PubMed

    Imai, T; Sano, A; Mikami, Y; Watanabe, K; Aoki, F H; Branchini, M L; Negroni, R; Nishimura, K; Miyaji, M

    2000-08-01

    Internal transcribed spacer (ITS) genes including the 5.8S ribosomal (r)RNA of Paracoccidioides brasiliensis were amplified and the DNA sequences were determined. Based on a comparison of the sequence information, a new polymerase chain reaction (PCR) primer pair was designed for specific amplification of DNA for P. brasiliensis. This primer pair amplified a 418-bp DNA sequence and was 100% successful in identifying 29 strains of P. brasiliensis (including the reference strains) isolated from the regions of Brazil, Costa Rica, Japan, Argentina or from different sources. The results of specificity tests of these primers to compare the fungus with those of Aspergillus fumigatus, Blastomyces dermatitidis, Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum and Penicillium marneffei are also reported.

  7. Porosity detection in ceramic armor tiles via ultrasonic time-of-flight

    SciTech Connect

    Margetan, Frank J.; Richter, Nathaniel; Jensen, Terrence

    2011-06-23

    Some multilayer armor panels contain ceramic tiles as one constituent, and porosity in the tiles can affect armor performance. It is well known that porosity in ceramic materials leads to a decrease in ultrasonic velocity. We report on a feasibility study exploring the use of ultrasonic time-of-flight (TOF) to locate and characterize porous regions in armor tiles. The tiles in question typically have well-controlled thickness, thus simplifying the translation of TOF data into velocity data. By combining UT velocity measurements and X-ray absorption measurements on selected specimens, one can construct a calibration curve relating velocity to porosity. That relationship can then be used to translate typical ultrasonic C-scans of TOF-versus-position into C-scans of porosity-versus-position. This procedure is demonstrated for pulse/echo, focused-transducer inspections of silicon carbide (SiC) ceramic tiles.

  8. Nonlinear elastic behavior of sub-critically damaged body armor panel

    NASA Astrophysics Data System (ADS)

    Fisher, Jason T.; Chimenti, D. E.

    2012-05-01

    A simple go/no-go test for body armor panels using pressure-sensitive, dye-indicator film (PSF) has been shown to be statistically effective in revealing subcritical damage to body armor panels. Previous measurements have shown that static indicator levels are accurately reproduced in dynamic loading events. Further impact tests on armor worn by a human resuscitation dummy using instrumented masses with an attached accelerometer and embedded force transducer have been performed and analyzed. New impact tests have shown a reliable correlation between PSF indication (as digitized images) and impact force for a wide range of impactor energies and masses. Numerical evaluation of digital PSF images is presented and correlated with impact parameters. Relationships between impactor mass and energy, and corresponding measured force are shown. We will also report on comparisons between ballistic testing performed on panels damaged under various impact conditions and tests performed on undamaged panels.

  9. Effect of Multi-Shot X-Ray Exposures in IFE Armor Materials

    SciTech Connect

    Latkowski, J F; Abbott, R P; Schmitt, R C; Bell, B K

    2004-12-10

    As part of the High Average Power Laser (HAPL) program the performance of tungsten as an armor material is being studied. While the armor would be exposed to neutrons, x-rays and ions within an inertial fusion energy (IFE) power plant, the thermomechanical effects are believed to dominate. Using a pulsed x-ray source, long-term exposures of tungsten have been completed at fluences that are of interest for the IFE application. Modeling is used in conjunction with experiments on the XAPPER x-ray damage facility in an effort to recreate the effects that would be expected in an operating IFE power plant. X-ray exposures have been completed for a variety of x-ray fluences and number of shots. Analysis of the samples suggests that surface roughening has a threshold that is very close to the fluences that reproduce the peak temperatures expected in an IFE armor material.

  10. Functional and structural analysis of the internal ribosome entry site present in the mRNA of natural variants of the HIV-1.

    PubMed

    Vallejos, Maricarmen; Carvajal, Felipe; Pino, Karla; Navarrete, Camilo; Ferres, Marcela; Huidobro-Toro, Juan Pablo; Sargueil, Bruno; López-Lastra, Marcelo

    2012-01-01

    The 5'untranslated regions (UTR) of the full length mRNA of the HIV-1 proviral clones pNL4.3 and pLAI, harbor an internal ribosomal entry site (IRES). In this study we extend this finding by demonstrating that the mRNA 5'UTRs of natural variants of HIV-1 also exhibit IRES-activity. Cap-independent translational activity was demonstrated using bicistronic mRNAs in HeLa cells and in Xenopus laevis oocytes. The possibility that expression of the downstream cistron in these constructs was due to alternative splicing or to cryptic promoter activity was ruled out. The HIV-1 variants exhibited significant 5'UTR nucleotide diversity with respect to the control sequence recovered from pNL4.3. Interestingly, translational activity from the 5'UTR of some of the HIV-1 variants was enhanced relative to that observed for the 5'UTR of pNL4.3. In an attempt to explain these findings we probed the secondary structure of the variant HIV-1 5'UTRs using enzymatic and chemical approaches. Yet subsequent structural analyses did not reveal significant variations when compared to the pNL4.3-5'UTR. Thus, the increased IRES-activity observed for some of the HIV-1 variants cannot be ascribed to a specific structural modification. A model to explain these findings is proposed.

  11. Hepatitis C virus internal ribosome entry site RNA contains a tertiary structural element in a functional domain of stem–loop II

    PubMed Central

    Lyons, Alita J.; Lytle, J. Robin; Gomez, Jordi; Robertson, Hugh D.

    2001-01-01

    The internal ribosome entry site (IRES) of hepatitis C virus (HCV) RNA contains >300 bases of highly conserved 5′-terminal sequence, most of it in the uncapped 5′-untranslated region (5′-UTR) upstream from the single AUG initiator triplet at which translation of the HCV polyprotein begins. Although progress has been made in defining singularities like the RNA pseudoknot near this AUG, the sequence and structural features of the HCV IRES which stimulate accurate and efficient initiation of protein synthesis are only partially defined. Here we report that a region further upstream from the AUG, stem–loop II of the HCV IRES, also contains an element of local tertiary structure which we have detected using RNase H cleavage and have mapped using the singular ability of two bases therein to undergo covalent intra-chain crosslinking stimulated by UV light. This pre-existing element maps to two non-contiguous stretches of the HCV IRES sequence, residues 53–68 and 103–117. Several earlier studies have shown that the correct sequence between bases 45 and 70 of the HCV IRES stem–loop II domain is required for initiation of protein synthesis. Because features of local tertiary structure like the one we report here are often associated with protein binding, we propose that the HCV stem–loop II element is directly involved in IRES action. PMID:11410661

  12. Functional and Structural Analysis of the Internal Ribosome Entry Site Present in the mRNA of Natural Variants of the HIV-1

    PubMed Central

    Vallejos, Maricarmen; Carvajal, Felipe; Pino, Karla; Navarrete, Camilo; Ferres, Marcela; Huidobro-Toro, Juan Pablo; Sargueil, Bruno; López-Lastra, Marcelo

    2012-01-01

    The 5′untranslated regions (UTR) of the full length mRNA of the HIV-1 proviral clones pNL4.3 and pLAI, harbor an internal ribosomal entry site (IRES). In this study we extend this finding by demonstrating that the mRNA 5′UTRs of natural variants of HIV-1 also exhibit IRES-activity. Cap-independent translational activity was demonstrated using bicistronic mRNAs in HeLa cells and in Xenopus laevis oocytes. The possibility that expression of the downstream cistron in these constructs was due to alternative splicing or to cryptic promoter activity was ruled out. The HIV-1 variants exhibited significant 5′UTR nucleotide diversity with respect to the control sequence recovered from pNL4.3. Interestingly, translational activity from the 5′UTR of some of the HIV-1 variants was enhanced relative to that observed for the 5′UTR of pNL4.3. In an attempt to explain these findings we probed the secondary structure of the variant HIV-1 5′UTRs using enzymatic and chemical approaches. Yet subsequent structural analyses did not reveal significant variations when compared to the pNL4.3-5′UTR. Thus, the increased IRES-activity observed for some of the HIV-1 variants cannot be ascribed to a specific structural modification. A model to explain these findings is proposed. PMID:22496887

  13. Manufacturing process scale-up of optical grade transparent spinel ceramic at ArmorLine Corporation

    NASA Astrophysics Data System (ADS)

    Spilman, Joseph; Voyles, John; Nick, Joseph; Shaffer, Lawrence

    2013-06-01

    While transparent Spinel ceramic's mechanical and optical characteristics are ideal for many Ultraviolet (UV), visible, Short-Wave Infrared (SWIR), Mid-Wave Infrared (MWIR), and multispectral sensor window applications, commercial adoption of the material has been hampered because the material has historically been available in relatively small sizes (one square foot per window or less), low volumes, unreliable supply, and with unreliable quality. Recent efforts, most notably by Technology Assessment and Transfer (TA and T), have scaled-up manufacturing processes and demonstrated the capability to produce larger windows on the order of two square feet, but with limited output not suitable for production type programs. ArmorLine Corporation licensed the hot-pressed Spinel manufacturing know-how of TA and T in 2009 with the goal of building the world's first dedicated full-scale Spinel production facility, enabling the supply of a reliable and sufficient volume of large Transparent Armor and Optical Grade Spinel plates. With over $20 million of private investment by J.F. Lehman and Company, ArmorLine has installed and commissioned the largest vacuum hot press in the world, the largest high-temperature/high-pressure hot isostatic press in the world, and supporting manufacturing processes within 75,000 square feet of manufacturing space. ArmorLine's equipment is capable of producing window blanks as large as 50" x 30" and the facility is capable of producing substantial volumes of material with its Lean configuration and 24/7 operation. Initial production capability was achieved in 2012. ArmorLine will discuss the challenges that were encountered during scale-up of the manufacturing processes, ArmorLine Optical Grade Spinel optical performance, and provide an overview of the facility and its capabilities.

  14. Experimental investigation of the response of gelatine behind the soft body armor.

    PubMed

    Luo, Shaomin; Xu, Cheng; Chen, Aijun; Zhang, Xiaoyun

    2016-09-01

    Understanding the transient cavity formation and transient pressure in the behind armor blunt trauma (BABT) is of fundamental importance in various research fields. In this paper, the transient response of ballistic gelatine behind the soft body armor subjected to the impacting of pistol bullets was studied. The profiles of the transient cavity in real time were captured by a high-speed camera, while the transient pressures were simultaneously recorded by pressure gauges. We find the cavity expansion-contraction movement is self-similar and can be expressed as a semi-ellipse. The gauges-recorded pressures reveal that three peaks on the pressure-time curve.

  15. Acousto-ultrasonic system for the inspection of composite armored vehicles

    NASA Astrophysics Data System (ADS)

    Godinez, Valery F.; Carlos, Mark F.; Delamere, Michael; Hoch, William; Fotopoulos, Christos; Dai, Weiming; Raju, Basavaraju B.

    2001-04-01

    In this paper the design and implementation of a unique acousto-ultrasonics system for the inspection of composite armored vehicles is discussed. The system includes a multi-sensor probe with a position-tracking device mounted on a computer controlled scanning bridge. The system also includes an arbitrary waveform generator with a multiplexer and a multi-channel acoustic emission board capable of simultaneously collecting and processing up to four acoustic signals in real time. C-scans of an armored vehicle panel with defects are presented.

  16. Ballistic Resistance of Armored Passenger Vehicles: Test Protocols and Quality Methods

    SciTech Connect

    Jeffrey M. Lacy; Robert E. Polk

    2005-07-01

    This guide establishes a test methodology for determining the overall ballistic resistance of the passenger compartment of assembled nontactical armored passenger vehicles (APVs). Because ballistic testing of every piece of every component of an armored vehicle is impractical, if not impossible, this guide describes a testing scheme based on statistical sampling of exposed component surface areas. Results from the test of the sampled points are combined to form a test score that reflects the probability of ballistic penetration into the passenger compartment of the vehicle.

  17. Biophysical Assessment and Predicted Thermophysiologic Effects of Body Armor

    PubMed Central

    Potter, Adam W.; Gonzalez, Julio A.; Karis, Anthony J.; Xu, Xiaojiang

    2015-01-01

    Introduction Military personnel are often required to wear ballistic protection in order to defend against enemies. However, this added protection increases mass carried and imposes additional thermal burden on the individual. Body armor (BA) is known to reduce combat casualties, but the effects of BA mass and insulation on the physical performance of soldiers are less well documented. Until recently, the emphasis has been increasing personal protection, with little consideration of the adverse impacts on human performance. Objective The purpose of this work was to use sweating thermal manikin and mathematical modeling techniques to quantify the tradeoff between increased BA protection, the accompanying mass, and thermal effects on human performance. Methods Using a sweating thermal manikin, total insulation (IT, clo) and vapor permeability indexes (im) were measured for a baseline clothing ensemble with and without one of seven increasingly protective U.S. Army BA configurations. Using mathematical modeling, predictions were made of thermal impact on humans wearing each configuration while working in hot/dry (desert), hot/humid (jungle), and temperate environmental conditions. Results In nearly still air (0.4 m/s), IT ranged from 1.57 to 1.63 clo and im from 0.35 to 0.42 for the seven BA conditions, compared to IT and im values of 1.37 clo and 0.45 respectively, for the baseline condition (no BA). Conclusion Biophysical assessments and predictive modeling show a quantifiable relationship exists among increased protection and increased thermal burden and decreased work capacity. This approach enables quantitative analysis of the tradeoffs between ballistic protection, thermal-work strain, and physical work performance. PMID:26200906

  18. Skeletal histology of the dermal armor of Placodontia: the occurrence of 'postcranial fibro-cartilaginous bone' and its developmental implications.

    PubMed

    Scheyer, Torsten M

    2007-12-01

    Placodontia (Reptilia: Sauropterygia) is a group of enigmatic armored marine reptiles restricted to the Triassic time period. Only a single row of osteoderms dorsal to the spine is present in the basal placodontoid Placodus gigas, whereas derived cyamodontoids superficially resemble turtles in enclosing their body in an armor shell. Despite the extensive occurrence of the dermal armor in the derived cyamodontoid group, little research has focused on its bone histology and development. Here, I present an overview of the bone microstructures that reveals the unique presence of cartilaginous tissue in the postcranial armor plates. Placodont armor plates stand in contrast to osteoderms of other tetrapods that develop intramembraneously or through metaplastic ossification without cartilaginous preformation. The different developmental pathways leading to this 'postcranial fibro-cartilaginous bone' tissue found in placodont plates compared to the dermal bone tissues of most other tetrapod osteoderms indicate the non-homology of these structures. A resulting morphogenetic model of histogenesis is given to exemplify how the derived armor morphologies (i.e. spiked, flat polygonal and hexagonal, and rhomboidal shapes) together with the peculiar bone histologies could have developed through differential growth. In accordance with the pachyostotic limb bones of placodonts, the presence of the compact 'postcranial fibro-cartilaginous bone' is interpreted as an osteosclerotic trend in the armor plates which aids in buoyancy control and affects maneuverability and swimming speed.

  19. Improved Bacterial 16S rRNA Gene (V4 and V4-5) and Fungal Internal Transcribed Spacer Marker Gene Primers for Microbial Community Surveys.

    PubMed

    Walters, William; Hyde, Embriette R; Berg-Lyons, Donna; Ackermann, Gail; Humphrey, Greg; Parada, Alma; Gilbert, Jack A; Jansson, Janet K; Caporaso, J Gregory; Fuhrman, Jed A; Apprill, Amy; Knight, Rob

    2016-01-01

    Designing primers for PCR-based taxonomic surveys that amplify a broad range of phylotypes in varied community samples is a difficult challenge, and the comparability of data sets amplified with varied primers requires attention. Here, we examined the performance of modified 16S rRNA gene and internal transcribed spacer (ITS) primers for archaea/bacteria and fungi, respectively, with nonaquatic samples. We moved primer bar codes to the 5' end, allowing for a range of different 3' primer pairings, such as the 515f/926r primer pair, which amplifies variable regions 4 and 5 of the 16S rRNA gene. We additionally demonstrated that modifications to the 515f/806r (variable region 4) 16S primer pair, which improves detection of Thaumarchaeota and clade SAR11 in marine samples, do not degrade performance on taxa already amplified effectively by the original primer set. Alterations to the fungal ITS primers did result in differential but overall improved performance compared to the original primers. In both cases, the improved primers should be widely adopted for amplicon studies. IMPORTANCE We continue to uncover a wealth of information connecting microbes in important ways to human and environmental ecology. As our scientific knowledge and technical abilities improve, the tools used for microbiome surveys can be modified to improve the accuracy of our techniques, ensuring that we can continue to identify groundbreaking connections between microbes and the ecosystems they populate, from ice caps to the human body. It is important to confirm that modifications to these tools do not cause new, detrimental biases that would inhibit the field rather than continue to move it forward. We therefore demonstrated that two recently modified primer pairs that target taxonomically discriminatory regions of bacterial and fungal genomic DNA do not introduce new biases when used on a variety of sample types, from soil to human skin. This confirms the utility of these primers for

  20. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... plant and fiber optic cable plant. (b) Method of measurement. (1) The shield or armor ground resistance measurement shall be made between the copper cable and wire shield and ground and between the fiber optic... instructions. (d) Applicable results. (1) For all new copper cable and wire facilities and all new fiber...

  1. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... plant and fiber optic cable plant. (b) Method of measurement. (1) The shield or armor ground resistance measurement shall be made between the copper cable and wire shield and ground and between the fiber optic... instructions. (d) Applicable results. (1) For all new copper cable and wire facilities and all new fiber...

  2. 7 CFR 1755.406 - Shield or armor ground resistance measurements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... plant and fiber optic cable plant. (b) Method of measurement. (1) The shield or armor ground resistance measurement shall be made between the copper cable and wire shield and ground and between the fiber optic... instructions. (d) Applicable results. (1) For all new copper cable and wire facilities and all new fiber...

  3. Report to the Attorney General on Body Armor Safety Initiative Testing and Activities

    DTIC Science & Technology

    2005-08-24

    Analysis of Results by Percentage of Zylon ® in Armor ..................................................................12 C. Analysis of Results by...18 B. Comparative Analysis of Zylon ® from Different Sources ..............................................................19 C...Changes in Mechanical Properties of Zylon ® Yarn ........................................................................19 D. Chemical Changes in Zylon

  4. 77 FR 22345 - Agency Information Collection Activities: Proposed Collection; Comments Requested; Body Armor in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-13

    ... correctional officers to mitigate the risks associated with prison environments. There is little data on body... Federal and State prisons will be asked to select one administrator to respond. (b) For the Body Armor... prisons. (5) An estimate of the total number of respondents and the amount of time estimated for...

  5. 46 CFR 111.05-7 - Armored and metallic sheathed cable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Armored and metallic sheathed cable. 111.05-7 Section 111.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems §...

  6. An Evaluation of Physical Readiness Training in Armor One Station Unit Training

    DTIC Science & Technology

    1984-08-01

    behavior modification principles, had each soldier repeat a gradually increasing number of sets of pushups, with each set being 50% of his maximum...discussing the relative importance of the pushup, situp, and 2-mile run subtests in the APRT. Keywords: Armor; Army training; Behavior ; Modification ; Muscles; Performand (human); Physical fitness; Predictions; Training.

  7. Mitigation Systems for Confined Blast Loading - Crew Protection in Armored Vehicles

    DTIC Science & Technology

    2009-04-01

    reactants; this volume contains about 80 percent of the original reactants by weight. Sintered bronze barriers were found to be effective in...Effects of Tungsten Alloy Property Variations on Penetrator Performance for Spaced Armors.” Advances in Powder Metallurgy and Particulate Materials

  8. MEMS, Nanotechnology and Spintronics for Sensor Enhanced Armor, NDE and Army Applications

    DTIC Science & Technology

    2009-06-16

    Crew Interface and Automation • Robotic Follower ATD • ARV Robotic Technologies Program SMART ARMOR Battery Pack w/ Integrated Heat Exchanger CONDITION...of MI, Prof. Wise ACTIVE STENTS : Wireless Readout of Intra-Arterial Pressure and Flow Suitable for the carotid arteries; not yet small enough for the

  9. General Tests of Personal Protective Equipment (Non-ballistic) - Soft Armor

    DTIC Science & Technology

    2012-07-23

    Textured or Multifilament Nylon, 15 November 1996. c. MIL-W-17337F, Military Specification: Webbing, Textile , Woven Nylon, 22 January 1990. d...Equipment ( Non -ballistic) - Soft Armor 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHORS 5d. PROJECT NUMBER...Equipment Non -ballistic 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF

  10. Establishment of the armored scale, Rhizaspidiotus donacis, a biological control agent of Arundo donax

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The armored scale biological control agent, Rhizaspidiotus donacis (Leonardi) (Hemiptera; Diaspididae) has established populations on the invasive weed, Arundo donax L. (Poaceae; Arundinoideae) in Del Rio (Val Verde, Co.) and in field plots at the USDA-APHIS-PPQ-Moore Airbase, Edinburg (Hidalgo Co.)...

  11. Growth of Sapphire Single Crystals Transparent Armor by a Modified Verneuil Technique.

    DTIC Science & Technology

    modified Verneuil technique for transparent armor applications. Seeded single crystals of sapphire were grown with widths in excess of 2 1/2 inches, lengths...single crystals by the ’strip’ Verneuil technique is feasible. An engineering cost analysis indicated that 8 inch by 1/4 inch sapphire windows could

  12. Armor Solutions for Energetic and Non-Energetic Novel Defeat Mechanisms

    DTIC Science & Technology

    2015-09-28

    distribution unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Summary of prototyping efforts for next generation armor designs using advanced...configuration management, materials development, coatings technology, packaging technology and overall systems engineering. Prototype and integrated... Tooling Processes 100% 4 TASK 4A: Component design and fabrication 100% 5 TASK 5A: Produce Developmental Units 100% 6 Quarterly Technical and Business

  13. Optimization of armored spherical tanks for storage on the lunar surface

    NASA Technical Reports Server (NTRS)

    Bents, D. J.; Knight, D. A.

    1992-01-01

    A redundancy strategy for reducing micrometeroid armoring mass is investigated, with application to cryogenic reactant storage for a regenerative fuel cell (RFC) on the lunar surface. In that micrometeoroid environment, the cryogenic fuel must be protected from loss due to tank puncture. The tankage must have a sufficiently high probability of survival over the length of the mission so that the probability of system failure due to tank puncture is low compared to the other mission risk factors. Assuming that a single meteoroid penetration can cause a storage tank to lose its contents, two means are available to raise the probability of surviving micrometeoroid attack to the desired level. One can armor the tanks to a thickness sufficient to reduce probability of penetration of any tank to the desired level or add extra capacity in the form of spare tanks that results in survival of a given number out of the ensemble at the desired level. A combination of these strategies (armoring and redundancy) is investigated. The objective is to find the optimum combination which yields the lowest shielding mass per cubic meter of surviving fuel out of the original ensemble. The investigation found that, for the volumes of fuel associated with multikilowatt class cryo storage RFC's, and the armoring methodology and meteoroid models used, storage should be fragmented into small individual tanks. Larger installations (more fuel) pay less of a shielding penalty than small installations. For the same survival probability over the same time period, larger volumes will require less armoring mass per unit volume protected.

  14. Secondary structure analyses of the nuclear rRNA internal transcribed spacers and assessment of its phylogenetic utility across the Brassicaceae (mustards).

    PubMed

    Edger, Patrick P; Tang, Michelle; Bird, Kevin A; Mayfield, Dustin R; Conant, Gavin; Mummenhoff, Klaus; Koch, Marcus A; Pires, J Chris

    2014-01-01

    The internal transcribed spacers of the nuclear ribosomal RNA gene cluster, termed ITS1 and ITS2, are the most frequently used nuclear markers for phylogenetic analyses across many eukaryotic groups including most plant families. The reasons for the popularity of these markers include: 1.) Ease of amplification due to high copy number of the gene clusters, 2.) Available cost-effective methods and highly conserved primers, 3.) Rapidly evolving markers (i.e. variable between closely related species), and 4.) The assumption (and/or treatment) that these sequences are non-functional, neutrally evolving phylogenetic markers. Here, our analyses of ITS1 and ITS2 for 50 species suggest that both sequences are instead under selective constraints to preserve proper secondary structure, likely to maintain complete self-splicing functions, and thus are not neutrally-evolving phylogenetic markers. Our results indicate the majority of sequence sites are co-evolving with other positions to form proper secondary structure, which has implications for phylogenetic inference. We also found that the lowest energy state and total number of possible alternate secondary structures are highly significantly different between ITS regions and random sequences with an identical overall length and Guanine-Cytosine (GC) content. Lastly, we review recent evidence highlighting some additional problematic issues with using these regions as the sole markers for phylogenetic studies, and thus strongly recommend additional markers and cost-effective approaches for future studies to estimate phylogenetic relationships.

  15. Genotyping of Pneumocystis jirovecii isolates from Chinese HIV-infected patients based on nucleotide sequence variations in the internal transcribed spacer regions of rRNA genes.

    PubMed

    Li, Kai; He, Ai; Cai, Wei Ping; Tang, Xiao Ping; Zheng, Xiao Ying; Li, Zhuo Ya; Zhan, Xi Mei

    2013-01-01

    Genetic diversity of Pneumocystis jirovecii isolates based on internal transcribed spacer (ITS) of the nuclear rRNA locus has previously been reported. The information about ITS genotype and epidemiology of this organism in Chinese human immunodeficiency virus-infected patients has not been available. In this study, 12 bronchoalveolar lavage fluid specimens obtained from HIV-infected patients were analyzed by PCR followed by cloning, sequencing and typing. Three ITS1 genotypes (E, B and 'H') and four ITS2 genotypes (b, g, i and r) as previously reported were identified, the most common of which were E, b and i. Five ITS haplotypes (Eg, Eb, Bi, Er and 'H'r) and 19 new combination types were also identified with the most common types being Eg (four of 12 patients, 10 of 60 clones), Eb (three of 12 patients, 11 of 60 clones) and Bi (three of 12 patients, 10 of 60 clones). Nine patients were found to be co-infected with more than one ITS genotype of P. jirovecii. The prevalence of ITS genotypes in HIV patients from one Chinese hospital did not seem to be significantly different when compared to reports from other countries.

  16. Characterization of internal transcribed spacer (ITS1)-ITS2 region of ribosomal RNA gene from 25 species of Culicoides biting midges (Diptera: Ceratopogonidae) in Japan.

    PubMed

    Matsumoto, Y; Yanase, T; Tsuda, T; Noda, H

    2009-09-01

    We determined nucleotide sequences of the nuclear rDNA internal transcribed spacer (ITS)1-5.8S-ITS2a-2S-ITS2 region in 103 individuals of 25 Culicoides species (Diptera: Ceratopogonidae) from 11 locations in Japan. Ribosomal RNA genes, 5.8S and 2S rDNA, were highly conserved among the species with few variations. The ITS2a region showed length variation among species. Both ITS1 and ITS2 showed highly varied sequences among species. The noticeable indel regions among ITS1 sequences are present in some Culicoides species, separating species into two types having long or short ITS1 region. However, Culicoides cylindratus Kitaoka possesses both types of ITS1 in each individual; these results seem to indicate that the ITS1-long type was the prototype and the short type was produced through deletion in many Culicoides species. One species, belonging to subgenus Avaritia, possessed an Avaritia-specific sequence in ITS1 and phylogenetically formed a monophyletic group. Geographical genotypes in a species were not clear. Species-specific sequence features were observed, enabling molecular identification of Culicoides species.

  17. Silencing of hepatitis C virus replication by a non-viral vector based on solid lipid nanoparticles containing a shRNA targeted to the internal ribosome entry site (IRES).

    PubMed

    Torrecilla, Josune; Del Pozo-Rodríguez, Ana; Solinís, María Ángeles; Apaolaza, Paola S; Berzal-Herranz, Beatriz; Romero-López, Cristina; Berzal-Herranz, Alfredo; Rodríguez-Gascón, Alicia

    2016-10-01

    Gene silencing mediated by RNAi has gained increasing interest as an alternative for the treatment of infectious diseases such as refractory hepatitis C virus (HCV) infection. In this work we have designed and evaluated a non-viral vector based on solid lipid nanoparticles (SLN) bearing hyaluronic acid, protamine and a short hairpin RNA (shRNA74) targeted to the Internal Ribosome Entry Site (IRES) of the HCV. The vector was able to inhibit the expression of the HCV IRES in Huh-7 cells, with the inhibition level dependent on the shRNA74 to SLN ratio and on the shRNA74 dose added to the culture cells. The nanocarrier was also able to inhibit the replication in human hepatoma cells supporting a subgenomic HCV replicon (Huh-7 NS3-3'). The vector was quickly and efficiently internalized by the cells, and endocytosis was the most productive uptake mechanism for silencing. Clathrin-mediated endocytosis and to a lesser extent caveolae/lipid raft-mediated endocytosis were identified as endocytic mechanisms involved in the cell uptake. Internalization via the CD44 receptor was also involved, although this entry route seems to be less productive for silencing than endocytosis. The vector did not induce either hemolysis or agglutination of red cells in vitro, which was indicative of good biocompatibility. In summary, we have shown for the first time the ability of a non-viral SLN-based vector to silence a HCV replicon.

  18. A cytoplasmic 57-kDa protein that is required for translation of picornavirus RNA by internal ribosomal entry is identical to the nuclear pyrimidine tract-binding protein.

    PubMed Central

    Hellen, C U; Witherell, G W; Schmid, M; Shin, S H; Pestova, T V; Gil, A; Wimmer, E

    1993-01-01

    Initiation of translation of the RNA genomes of picornaviruses such as poliovirus and encephalomyocarditis virus is cap-independent and results from interaction of ribosomes with a segment of the 5' noncoding region of these mRNAs termed the internal ribosomal entry site. Genetic and biochemical studies have previously shown that a 57-kDa cytoplasmic RNA-binding protein (p57) plays an essential role in this translation mechanism. We have now found that p57 shares physical, biochemical, and antigenic properties with the pyrimidine tract-binding protein (PTB), a nuclear protein that has been implicated in various processes involving pre-mRNA. These data indicate that p57 and PTB are the same protein. Purified recombinant PTB bound specifically to a bulged hairpin within the internal ribosomal entry site of encephalomyocarditis virus and had a much lower affinity for a mutated derivative of this hairpin and for unrelated RNAs. Immunodepletion of p57/PTB from a HeLa cell-free lysate inhibited translation of poliovirus and encephalomyocarditis virus mRNAs but had no effect on translation of beta-globin mRNA, confirming the essential role of p57 in translation by internal ribosomal entry. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8395052

  19. Ballistic and Corrosion Analysis of New Military-Grade Magnesium Alloys AMX602 and ZAXE1711 For Armor Applications

    DTIC Science & Technology

    2012-02-01

    Ultimate Tensile Strength (MPa) Tensile Yield Strength (MPa) Elongation to Failure (%) AZ31B 245 150 7 Proposed Mg alloy 400 350 20 In 2009...Ballistic and Corrosion Analysis of New Military-Grade Magnesium Alloys AMX602 and ZAXE1711 for Armor Applications by Tyrone L. Jones...Magnesium Alloys AMX602 and ZAXE1711 for Armor Applications Tyrone L. Jones, Joseph P. Labukas, and Brian E. Placzankis Weapons and Materials

  20. Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade Martensitic Steel

    DTIC Science & Technology

    2013-06-01

    most of the commercially available metallic materials, in particular steels (including stainless steels ), super alloys, aluminum alloys, etc., can...REPORT Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade Martensitic Steel 14. ABSTRACT 16...Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade Martensitic Steel Report Title ABSTRACT A conventional gas metal

  1. A Historical Summary of the Armored Systems Modernization Program and the Lessons Learned from Its Interaction With the Acquisition Environment

    DTIC Science & Technology

    1992-06-01

    NO "VORK UNIT ACCESSION NO. 11 TITLE (Include Security Classification) A HISTORICl\\L SUMMARY OF THE ARMORED SYSTEMS IDDERNIZATION PRCGRAM AND·· THE...June 1992 iii DOWNGRADED APPROVED FOR PUBLIC RELEASE 9istribauon. is limited to U.S.. GOTlcrnmeftt .Ageneies and their ....·Contraet6fs...MANAGEMENT from the Author: Approved by: NAVAL·POSTGRADUATE SCHOOL June 1992 iii ABSTRACT The Armored Systems Modernization (ASM) Program’s acquisition

  2. Improved Bacterial 16S rRNA Gene (V4 and V4-5) and Fungal Internal Transcribed Spacer Marker Gene Primers for Microbial Community Surveys

    SciTech Connect

    Walters, William; Hyde, Embriette R.; Berg-Lyons, Donna; Ackermann, Gail; Humphrey, Greg; Parada, Alma; Gilbert, Jack A.; Jansson, Janet K.; Caporaso, J. Gregory; Fuhrman, Jed A.; Apprill, Amy; Knight, Rob; Bik, Holly

    2015-12-22

    ABSTRACT

    Designing primers for PCR-based taxonomic surveys that amplify a broad range of phylotypes in varied community samples is a difficult challenge, and the comparability of data sets amplified with varied primers requires attention. Here, we examined the performance of modified 16S rRNA gene and internal transcribed spacer (ITS) primers for archaea/bacteria and fungi, respectively, with nonaquatic samples. We moved primer bar codes to the 5′ end, allowing for a range of different 3′ primer pairings, such as the 515f/926r primer pair, which amplifies variable regions 4 and 5 of the 16S rRNA gene. We additionally demonstrated that modifications to the 515f/806r (variable region 4) 16S primer pair, which improves detection ofThaumarchaeotaand clade SAR11 in marine samples, do not degrade performance on taxa already amplified effectively by the original primer set. Alterations to the fungal ITS primers did result in differential but overall improved performance compared to the original primers. In both cases, the improved primers should be widely adopted for amplicon studies.

    ImportanceWe continue to uncover a wealth of information connecting microbes in important ways to human and environmental ecology. As our scientific knowledge and technical abilities improve, the tools used for microbiome surveys can be modified to improve the accuracy of our techniques, ensuring that we can continue to identify groundbreaking connections between microbes and the ecosystems they populate, from ice caps to the human body. It is important to confirm that modifications to these tools do not cause new, detrimental biases that would inhibit the field rather than continue to move it forward. We therefore demonstrated that two recently modified primer pairs that target taxonomically discriminatory regions of bacterial and fungal genomic DNA do not introduce new biases when used on a variety of sample types, from soil to

  3. Improved Bacterial 16S rRNA Gene (V4 and V4-5) and Fungal Internal Transcribed Spacer Marker Gene Primers for Microbial Community Surveys

    PubMed Central

    Walters, William; Hyde, Embriette R.; Berg-Lyons, Donna; Ackermann, Gail; Humphrey, Greg; Parada, Alma; Gilbert, Jack A.; Jansson, Janet K.; Caporaso, J. Gregory; Fuhrman, Jed A.; Apprill, Amy

    2015-01-01

    ABSTRACT Designing primers for PCR-based taxonomic surveys that amplify a broad range of phylotypes in varied community samples is a difficult challenge, and the comparability of data sets amplified with varied primers requires attention. Here, we examined the performance of modified 16S rRNA gene and internal transcribed spacer (ITS) primers for archaea/bacteria and fungi, respectively, with nonaquatic samples. We moved primer bar codes to the 5′ end, allowing for a range of different 3′ primer pairings, such as the 515f/926r primer pair, which amplifies variable regions 4 and 5 of the 16S rRNA gene. We additionally demonstrated that modifications to the 515f/806r (variable region 4) 16S primer pair, which improves detection of Thaumarchaeota and clade SAR11 in marine samples, do not degrade performance on taxa already amplified effectively by the original primer set. Alterations to the fungal ITS primers did result in differential but overall improved performance compared to the original primers. In both cases, the improved primers should be widely adopted for amplicon studies. IMPORTANCE We continue to uncover a wealth of information connecting microbes in important ways to human and environmental ecology. As our scientific knowledge and technical abilities improve, the tools used for microbiome surveys can be modified to improve the accuracy of our techniques, ensuring that we can continue to identify groundbreaking connections between microbes and the ecosystems they populate, from ice caps to the human body. It is important to confirm that modifications to these tools do not cause new, detrimental biases that would inhibit the field rather than continue to move it forward. We therefore demonstrated that two recently modified primer pairs that target taxonomically discriminatory regions of bacterial and fungal genomic DNA do not introduce new biases when used on a variety of sample types, from soil to human skin. This confirms the utility of these primers

  4. Probing the Mechanical Strength of an Armored Bubble and Its Implication to Particle-Stabilized Foams

    NASA Astrophysics Data System (ADS)

    Taccoen, Nicolas; Lequeux, François; Gunes, Deniz Z.; Baroud, Charles N.

    2016-01-01

    Bubbles are dynamic objects that grow and rise or shrink and disappear, often on the scale of seconds. This conflicts with their uses in foams where they serve to modify the properties of the material in which they are embedded. Coating the bubble surface with solid particles has been demonstrated to strongly enhance the foam stability, although the mechanisms for such stabilization remain mysterious. In this paper, we reduce the problem of foam stability to the study of the behavior of a single spherical bubble coated with a monolayer of solid particles. The behavior of this armored bubble is monitored while the ambient pressure around it is varied, in order to simulate the dissolution stress resulting from the surrounding foam. We find that above a critical stress, localized dislocations appear on the armor and lead to a global loss of the mechanical stability. Once these dislocations appear, the armor is unable to prevent the dissolution of the gas into the surrounding liquid, which translates into a continued reduction of the bubble volume, even for a fixed overpressure. The observed route to the armor failure therefore begins from localized dislocations that lead to large-scale deformations of the shell until the bubble completely dissolves. The critical value of the ambient pressure that leads to the failure depends on the bubble radius, with a scaling of Δ Pcollapse∝R-1 , but does not depend on the particle diameter. These results disagree with the generally used elastic models to describe particle-covered interfaces. Instead, the experimental measurements are accounted for by an original theoretical description that equilibrates the energy gained from the gas dissolution with the capillary energy cost of displacing the individual particles. The model recovers the short-wavelength instability, the scaling of the collapse pressure with bubble radius, and the insensitivity to particle diameter. Finally, we use this new microscopic understanding to predict

  5. Persistence of 10-year old Exxon Valdez oil on Gulf of Alaska beaches: the importance of boulder-armoring.

    PubMed

    Irvine, Gail V; Mann, Daniel H; Short, Jeffrey W

    2006-09-01

    Oil stranded as a result of the 1989 Exxon Valdez spill has persisted for >10 years at study sites on Gulf of Alaska shores distant from the spill's origin. These sites were contaminated by "oil mousse", which persists in these settings due to armoring of underlying sediments and their included oil beneath boulders. The boulder-armored beaches that we resampled in 1999 showed continued contamination by subsurface oil, despite their exposure to moderate to high wave energies. Significant declines in surface oil cover occurred at all study sites. In contrast, mousse has persisted under boulders in amounts similar to what was present in 1994 and probably in 1989. Especially striking is the general lack of weathering of this subsurface oil over the last decade. Oil at five of the six armored-beach sites 10 years after the spill is compositionally similar to 11-day old Exxon Valdez oil. Analysis of movements in the boulder-armor that covers the study beaches reveals that only minor shifts have occurred since 1994, suggesting that over the last five, and probably over the last 10 years, boulder-armors have remained largely unmoved at the study sites. These findings emphasize the importance of particular geomorphic parameters in determining stranded oil persistence. Surface armoring, combined with stranding of oil mousse, results in the unexpectedly lengthy persistence of only lightly to moderately weathered oil within otherwise high-energy wave environments.

  6. Persistence of 10-year old Exxon Valdez oil on Gulf of Alaska beaches: The importance of boulder-armoring

    USGS Publications Warehouse

    Irvine, Gail V.; Mann, Daniel H.; Short, Jeffrey W.

    2006-01-01

    Oil stranded as a result of the 1989 Exxon Valdez spill has persisted for >10 years at study sites on Gulf of Alaska shores distant from the spill's origin. These sites were contaminated by "oil mousse", which persists in these settings due to armoring of underlying sediments and their included oil beneath boulders. The boulder-armored beaches that we resampled in 1999 showed continued contamination by subsurface oil, despite their exposure to moderate to high wave energies. Significant declines in surface oil cover occurred at all study sites. In contrast, mousse has persisted under boulders in amounts similar to what was present in 1994 and probably in 1989. Especially striking is the general lack of weathering of this subsurface oil over the last decade. Oil at five of the six armored-beach sites 10 years after the spill is compositionally similar to 11-day old Exxon Valdez oil. Analysis of movements in the boulder-armor that covers the study beaches reveals that only minor shifts have occurred since 1994, suggesting that over the last five, and probably over the last 10 years, boulder-armors have remained largely unmoved at the study sites. These findings emphasize the importance of particular geomorphic parameters in determining stranded oil persistence. Surface armoring, combined with stranding of oil mousse, results in the unexpectedly lengthy persistence of only lightly to moderately weathered oil within otherwise high-energy wave environments.

  7. RNA Interference

    MedlinePlus

    ... NIGMS Home > Science Education > RNA Interference Fact Sheet RNA Interference Fact Sheet Tagline (Optional) Middle/Main Content Area What is RNA interference? RNA interference (RNAi) is a natural process ...

  8. Relationships between 16S-23S rRNA gene internal transcribed spacer DNA and genomic DNA similarities in the taxonomy of phototrophic bacteria

    NASA Astrophysics Data System (ADS)

    Okamura, K.; Hisada, T.; Takata, K.; Hiraishi, A.

    2013-04-01

    Rapid and accurate identification of microbial species is essential task in microbiology and biotechnology. In prokaryotic systematics, genomic DNA-DNA hybridization is the ultimate tool to determine genetic relationships among bacterial strains at the species level. However, a practical problem in this assay is that the experimental procedure is laborious and time-consuming. In recent years, information on the 16S-23S rRNA gene internal transcribed spacer (ITS) region has been used to classify bacterial strains at the species and intraspecies levels. It is unclear how much information on the ITS region can reflect the genome that contain it. In this study, therefore, we evaluate the quantitative relationship between ITS DNA and entire genomic DNA similarities. For this, we determined ITS sequences of several species of anoxygenic phototrophic bacteria belonging to the order Rhizobiales, and compared with DNA-DNA relatedness among these species. There was a high correlation between the two genetic markers. Based on the regression analysis of this relationship, 70% DNA-DNA relatedness corresponded to 92% ITS sequence similarity. This suggests the usefulness of the ITS sequence similarity as a criterion for determining the genospecies of the phototrophic bacteria. To avoid the effects of polymorphism bias of ITS on similarities, PCR products from all loci of ITS were used directly as genetic probes for comparison. The results of ITS DNA-DNA hybridization coincided well with those of genomic DNA-DNA relatedness. These collective data indicate that the whole ITS DNA-DNA similarity can be used as an alternative to genomic DNA-DNA similarity.

  9. Protection mechanisms of the iron-plated armor of a deep-sea hydrothermal vent gastropod

    PubMed Central

    Yao, Haimin; Dao, Ming; Imholt, Timothy; Huang, Jamie; Wheeler, Kevin; Bonilla, Alejandro; Suresh, Subra; Ortiz, Christine

    2010-01-01

    Biological exoskeletons, in particular those with unusually robust and multifunctional properties, hold enormous potential for the development of improved load-bearing and protective engineering materials. Here, we report new materials and mechanical design principles of the iron-plated multilayered structure of the natural armor of Crysomallon squamiferum, a recently discovered gastropod mollusc from the Kairei Indian hydrothermal vent field, which is unlike any other known natural or synthetic engineered armor. We have determined through nanoscale experiments and computational simulations of a predatory attack that the specific combination of different materials, microstructures, interfacial geometries, gradation, and layering are advantageous for penetration resistance, energy dissipation, mitigation of fracture and crack arrest, reduction of back deflections, and resistance to bending and tensile loads. The structure-property-performance relationships described are expected to be of technological interest for a variety of civilian and defense applications. PMID:20133823

  10. A parametric design of ceramic faced composite armor subject to air weapon threats

    NASA Astrophysics Data System (ADS)

    Guo, Y. N.; Sun, Q.

    2015-12-01

    By taking into consideration the two categories of military projectile threats to aircraft structures, an optimal layer configuration of ceramic faced composite armor was designed in this paper. Using numerical simulations and the same layer arrangement of ceramic, UHMWPE, and carbon fiber laminates, a parametric finite element model using LS-DYNA code was built. Several thickness combinations were analyzed in order to determine the final lightest configuration that is capable of supporting a high-speed impact load and HEI blast wave load, which implements a high anti-penetration design for aircraft armor. This configuration can be used to improve the anti-impact ability of aircraft structures as well as achieve a structure/function integration design that considers a lighter weight.

  11. Flexibility and protection by design: imbricated hybrid microstructures of bio-inspired armor.

    PubMed

    Rudykh, Stephan; Ortiz, Christine; Boyce, Mary C

    2015-04-07

    Inspired by the imbricated scale-tissue flexible armor of elasmoid fish, we design hybrid stiff plate/soft matrix material architectures and reveal their ability to provide protection against penetration while preserving flexibility. Indentation and bending tests on bio-inspired 3D-printed prototype materials show that both protection and flexibility are highly tunable by geometrical parameters of the microstructure (plate inclination angle and volume fraction). We show that penetration resistance can be amplified by a factor of 40, while flexibility decreases in less than 5 times. Different deformation resistance mechanisms are found to govern flexibility (inter-plate matrix shear) versus penetration resistance (localized plate bending) for this microstructural architecture which, in turn, enables separation of these functional requirements in the material design. These experiments identify the tradeoffs between these typically conflicting properties as well as the ability to design the most protective material architecture for a required flexibility, providing new design guidelines for enhanced flexible armor systems.

  12. Armor Development from Decapitated Flash Flood Bores in Supply-Limited Flume Experiments

    NASA Astrophysics Data System (ADS)

    Goodwin, K.; Rhodes, R.; Johnson, J. P.

    2013-12-01

    In rivers assumed to have quasi-normal flow, three main processes have been used to explain bed surface armoring: i) selective entrainment and transport of smaller grains, ii) limited supply of smaller grain sizes, and iii) equal mobility of grains of different sizes, which develops through natural feedbacks such that larger, less mobile grains are enriched on the surface relative to smaller grains. Flash flood-dominated river channels in arid environments often completely lack surface armoring, yet it is unclear whether increased sediment supply or transport of all grain sizes prevents armor development. In order to examine armor development in an end-member case of non-normal flow, we conducted a series of laboratory experiments using flash flood bores. The flume is 33.5 m long, 0.5 m wide, 0.8 m tall, and capable of creating reproducible flood bores by raising a high-speed computerized lift gate and releasing impounded water. For each experiment, the gate was quickly lowered as soon as the flood bore traveled the length of the flume, 'decapitating' the bore from subsequent flow, to better isolate the effects of the bore alone on entrainment and transport. Sediment was not fed into the upstream end of the flume and only sourced from the gravel bed (2 mm to 40 mm), resulting in supply-limited experimental conditions. In response to repeated flood bores, the surface grain size distribution rapidly coarsened. We interpret that kinetic sieving was the dominant cause of surface armoring in these experiments. LiDAR scans of the bed topography from before and after each bore show increased surface roughness due to grain size changes, but small surface elevation changes due to relatively limited erosion. Digital gravelometry from photographs taken after each bore show increased armoring, while sediment transported out the downstream end of the flume tended to be as coarse or coarser than the bed surface. Travel distances of three sizes of RFID-tagged tracer clasts show

  13. Advanced Modeling Strategies for the Analysis of Tile-Reinforced Composite Armor

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Chen, Tzi-Kang

    1999-01-01

    A detailed investigation of the deformation mechanisms in tile-reinforced armored components was conducted to develop the most efficient modeling strategies for the structural analysis of large components of the Composite Armored Vehicle. The limitations of conventional finite elements with respect to the analysis of tile-reinforced structures were examined, and two complementary optimal modeling strategies were developed. These strategies are element layering and the use of a tile-adhesive superelement. Element layering is a technique that uses stacks of shear deformable shell elements to obtain the proper transverse shear distributions through the thickness of the laminate. The tile-adhesive superelement consists of a statically condensed substructure model designed to take advantage of periodicity in tile placement patterns to eliminate numerical redundancies in the analysis. Both approaches can be used simultaneously to create unusually efficient models that accurately predict the global response by incorporating the correct local deformation mechanisms.

  14. Transient pressure wave in the behind armor blunt trauma: experimental and computational investigation.

    PubMed

    Luo, Shaomin; Xu, Cheng; Wang, Shu; Wen, Yaoke

    2017-02-01

    In the last few decades, various researches focus on the transient pressure in the behind armor blunt trauma. This paper presented a investigation on the transient pressure in the ballistic gelatin behind a soft body armor subjected to the impacting from three ammunitions. Experimental results show that three peaks appear on the pressure-time curves without taking into account the ammunition type and the impact velocity. Furthermore, numerical models of the test were created to compare modelling results to the pressure from the pressure gauges buried in the gelatin block. The main features on the pressure-time cure were discussed to analyze the wave formation and propagation. With the verified model, the effect of the boundary was also investigated to explain the wave reflection which appeared after two peaks.

  15. Development of an automated fuzing station for the future armored resupply vehicle

    SciTech Connect

    Chesser, J.B.; Jansen, J.F.; Lloyd, P.D.; Varma, V.K.

    1995-03-01

    The US Army is developing the Advanced Field Artillery System (SGSD), a next generation armored howitzer. The Future Armored Resupply Vehicle (FARV) will be its companion ammunition resupply vehicle. The FARV with automate the supply of ammunition and fuel to the AFAS which will increase capabilities over the current system. One of the functions being considered for automation is ammunition processing. Oak Ridge National Laboratory is developing equipment to demonstrate automated ammunition processing. One of the key operations to be automated is fuzing. The projectiles are initially unfuzed, and a fuze must be inserted and threaded into the projectile as part of the processing. A constraint on the design solution is that the ammunition cannot be modified to simplify automation. The problem was analyzed to determine the alignment requirements. Using the results of the analysis, ORNL designed, built, and tested a test stand to verify the selected design solution.

  16. Quasi-Static Tensile Stress Strain Curves--II, Rolled Homogeneous Armor

    DTIC Science & Technology

    1976-11-01

    Aluminum Alloys, 2024-T3510, 5083-H131 and 7039-T64 as Measured by a Sonic Technique", Ballistic Research Laboratories, Abei-deen Proving Ground , MD. 6R...Hugoniot of Rolled Homogeneous Armor ", Ballistic Research Laboratories, Aberdeen Proving Ground , MD. 7 11. TEST PROCEDURES The material properties of...Gov’t. agencies only; Test and Evaluation; NOV 1976. Other requests shall be referred to Ballistic Research Laboratories, Aberdeen Proving Ground , MD

  17. Origin of the 44-mm Behind-Armor Blunt Trauma Standard

    DTIC Science & Technology

    2012-08-01

    soap ,35 and asse sing animal injury when the animal i wearing armor.5 Re earchers have also made attempts to quantify the level of injury and...1 DIRECTOR US ARMY RESEARCH LAB IMAL HRA 2800 POWDER MILL RD ADELPHI MD 20783-1197 1 DIRECTOR US ARMY RESEARCH LAB RDRL CIO LL...2800 POWDER MILL RD ADELPHI MD 20783-1197 NO. OF COPIES ORGANIZATION 1 USARL RDRL SLE R FLORES WSMR NM 88002-5513

  18. Identification of NDE Methods for Inspection Multi-Layer Ceramic Composite Armor

    DTIC Science & Technology

    2010-01-08

    composite armor The NDE methods under evaluation include: 1)-immersion phased array ultrasonics , 2)- through- transmission, direct-digital x-ray imaging...results in very long data acquisition times as compare to phased array scans. 5. Air Coupled Ultrasonic methods The last NDE method...include: 1)-immersion phased array ultrasonics , 2)- through-transmission, direct-digital x-ray imaging, 3)-non-contact scanning microwaves, 4)-air

  19. Armored Family of Vehicles (AFV). Phase 1 Report. Book 3. Volumes 5 thru 8

    DTIC Science & Technology

    1987-08-31

    Purpose Fire Support Platoon (APFSP) 3. Armored Gun System O&O Concept 4. Comparison of Direct Fire Gun Systems (105mm VS 120mm) 5. Results of the...this phase, simulators should be identified which will support both the design effort, New Equipment Training ( NET ), fielding, and sustainment...Equipment Training. (1) The AFY management organization will maintain overall program responsibility for NET in coordination with AMC and TRADOC; however

  20. What is the Role of Heavy Armor in the Army of 2020?

    DTIC Science & Technology

    2012-12-06

    the strategic environment and lead to situations that would represent a direct threat to the national security interests of the United States... Oklahoma Press, 2011), 44. 58 Aleksandr A. Svechin, Strategy, ed. Kent D. Lee; (Minneapolis, MN: East View Publications, 1992), 1-5. 59 Christopher Paul...DePuy’s work underlined the importance of providing a clearly defined vision for employing its armor forces.75 As the one of the leading developers of

  1. A Review and Annotated Bibliography of Armor Gunnery Training Device Effectiveness Literature

    DTIC Science & Technology

    1993-11-01

    performance for each TC/gunner pair was determined after the competition by both the platoon leader and platoon members’ reenactment on paper of each...a rear-projected movie that depicts armor targets moving across realistic terrain. Each TC-gunner pair engaged 27 targets, nine per film . The order...of presentation was counterbalanced so that each of three films was shown an equal number of occasions first, second, and third. d. Number of Different

  2. Defeat at Kasserine: American Armor Doctrine, Training, and Battle Command in Northwest Africa, World War II

    DTIC Science & Technology

    2006-05-31

    is the enemy of change.1 Edward L. Katzenbach Jr. The 1st Armored Division was activated on 15 July 1940 at Ft. Knox, Kentucky. It was the first of...experienced Axis force. 1Edward L. Katzenbach Jr., “The Horse Cavalry in the Twentieth Century,” Public...Joint Forces Quarterly 20 (autumn/winter 1998-99): 71-77. Katzenbach Jr., Edward L. “The Horse Cavalry in the Twentieth Century.” Public Policy 7

  3. Stability of hard plates on soft substrates and application to the design of bioinspired segmented armor

    NASA Astrophysics Data System (ADS)

    Martini, R.; Barthelat, F.

    2016-07-01

    Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention from their unique and attractive combinations of hardness, flexibility and light weight. In particular, the extreme contrast of stiffness between hard plates and surrounding soft tissues give rise to unusual and attractive mechanisms, which now serve as model for the design of bio-inspired armors. Despite a growing interest in bio-inspired flexible protection, there is little guidelines as to the choice of materials, optimum thickness, size, shape and arrangement for the protective plates. In this work, we focus on a failure mode we recently observed on natural and bio-inspired scaled armors: the unstable tilting of individual scales subjected to off-centered point forces. We first present a series of experiments on this system, followed by a model based on contact mechanics and friction. We condense the result into a single stability diagram which capture the key parameters that govern the onset of plate tilting from a localized force. We found that the stability of individual plates is governed by the location of the point force on the plate, by the friction at the surface of the plate, by the size of the plate and by the stiffness of the substrate. We finally discuss how some of these parameters can be optimized at the design stage to produce bio-inspired protective systems with desired combination of surface hardness, stability and flexural compliance.

  4. Simulation Tools for Ultrasonic Inspections of Multi-Layer Armor Panels

    NASA Astrophysics Data System (ADS)

    Richter, Nathaniel; Margetan, Frank J.; Gray, Tim; Thompson, R. Bruce

    2011-06-01

    Some armor panels are fabricated from several layers of material including ceramics, graphite and/or glass composites, and rubber. This multi-layer makeup can complicate UT inspection, since many possible sound paths (including intra-layer reverberations) can contribute to observed UT signals. At last year's QNDE conference we reported on baseline property measurements (density, sound speed, attenuation, etc.) for the constituent layers of one prototype panel, and we discussed how that information was used to design an ultrasonic inspection to look for disbonding at interfaces. We now report on progress to develop better simulation tools for armor panel inspections. In particular we consider normal-incidence pulse/echo inspections and use a paraxial beam model to predict time-domain signals for unflawed panels and those containing large delaminations. The model uses the frequency-dependent baseline property data as inputs, and treats beam spread and focusing effects. We describe the modeling approach and present comparisons of model predictions to the experimental data gathered last year during inspections of five-layer armor panels.

  5. Optimization of armored spherical tanks for storage on the lunar surface

    NASA Technical Reports Server (NTRS)

    Bents, D. J.; Knight, D. A.

    1992-01-01

    A redundancy strategy for reducing micrometeroid armoring mass is investigated, with application to cryogenic reactant storage for a regenerative fuel cell (RFC) on the lunar surface. In that micrometeoroid environment, the cryogenic fuel must be protected from loss due to tank puncture. The tankage must have a sufficiently high probability of survival over the length of the mission so that the probability of system failure due to tank puncture is low compared to the other mission risk factors. Assuming that a single meteoroid penetration can cause a storage tank to lose its contents, two means are available to raise the probability of surviving micrometeoroid attack to the desired level. One can armor the tanks to a thickness sufficient to reduce probability of penetration of any tank to the desired level or add extra capacity in the form of space tanks that results in survival of a given number out of the ensemble at the desired level. A combination of these strategies (armor and redundancy) is investigated.

  6. Initiation of RNA synthesis in vitro by vesicular stomatitis virus: single internal initiation in the presence of aurintricarboxylic acid and vanadyl ribonucleoside complexes.

    PubMed Central

    Talib, S; Hearst, J E

    1983-01-01

    In the presence of aurintricarboxylic acid (ATA) and vanadyl ribonucleoside complexes (VRC), we have isolated and characterized a small RNA, product of VSV in vitro transcription. This RNA is capped and lacks poly(A) at its 3'-end. Nucleotide sequence analysis revealed that this RNA corresponds to the 5'-terminal transcription product of the N-gene. The termination of the transcription occurs precisely at the 118th base from the 3'-end of the VSV genome. Analysis of the nucleotide sequence around this region reveals a potential secondary structure. Photoreaction of the VSV with 4'-substituted psoralen fails to inhibit the synthesis of the 68-mer RNA under conditions where full length mRNA synthesis is blocked, indicating that the psoralen binding site is located further into the N-gene. Since this RNA is the only in vitro transcription product synthesized under these conditions, the existence of two types of polymerase activities, one for the synthesis of leader RNA and one for mRNA, is suggested. Images PMID:6314272

  7. Damage Assessment in TiB2 Ceramic Armor Targets

    DTIC Science & Technology

    2001-11-01

    International Ceramic Working Group Meeting (DOD/DOE), Aberdeen Proving Ground, MD, 23–24 April 1997. Green, W. H., K . J. Doherty, N. L. Rupert, and J. M. Wells...Penetration.” International Journal of Impact Engineering, vol. 24, pp. 259–275, 2000. 36 Rupert, N. L., W. H. Green, K . J. Doherty, and J. M. Wells...BFVS SFAE GCSS W BV S DAVIS WARREN MI 48397-5000 3 CDR CARDEROCK DIV NSWC R PETERSON CODE 28 K G LIPETZKY CODE 615 W T MESSICK

  8. Ambient air cooling for concealed soft body armor in a hot environment.

    PubMed

    Ryan, Greg A; Bishop, Stacy H; Herron, Robert L; Katica, Charles P; Elbon, Bre'anna L; Bosak, Andrew M; Bishop, Phillip

    2014-01-01

    Concealed soft body armor inhibits convective and evaporative heat loss and increases heat storage, especially in hot environments. One option to potentially mitigate heat storage is to promote airflow under the soft body armor. The purpose of this study was to evaluate the effect of ambient air induction (∼100 liters per minute) on heat strain while wearing concealed soft body armor in a hot environment (wet bulb globe temperature = 30°C). A counter-balanced, repeated measures protocol was performed with nine healthy male volunteers. Participants were fitted with either a traditional or modified Level II concealed soft body armor. Participants performed cycles of 12 min of walking (1.25 liters per minute) and 3 min of arm curls (0.6 liters per minute) for a total of 60 min. Two-way repeated measures ANOVA was used to assess the mean differences in physiological measures (rectal temperature, heart rate, micro-environment [temperature and relative humidity]). Post hoc Bonferroni analysis and paired samples t-tests (alpha = 0.01) were conducted on omnibus significant findings. Perceptual measures (perceived exertion, thermal comfort) were analyzed using Wilcoxon Signed Ranks Tests. Modification led to an improvement in perceived exertion at 45 min (MOD: 10 ± 1; CON: 11 ± 2; p ≤ 0.001) and 60 min (MOD: 10 ± 2; CON: 12 ± 2; p ≤ 0.001) and a reduction in micro-environment temperature in MOD (1.0 ± 0.2°C, p = 0.03) compared to CON. Modification did not attenuate change in rectal temperature or heart rate (p < 0.01) during 60-min work bout. Change in rectal temperature approached significance between MOD and CON at the end of the work bout (MOD: 0.4 ± 0.2°C; CON: 0.7 ± 0.3°C; p = 0.048). The slope of rectal temperature was significantly greater (p = 0.04) under CON compared to MOD. These data suggest that air induction may provide small benefits while wearing concealed soft body armor, though improvements are needed to lessen physiological strain.

  9. MicroRNAs in Cancer: the 22nd Hiroshima Cancer Seminar/the 4th Japanese Association for RNA Interference Joint International Symposium, 30 August 2012, Grand Prince Hotel Hiroshima.

    PubMed

    Tahara, Hidetoshi; Kay, Mark A; Yasui, Wataru; Tahara, Eiichi

    2013-05-01

    The joint international symposium of the 22nd Hiroshima Cancer Seminar and the 4th Japanese Association for RNA Interference focused on a pivotal role of microRNAs in carcinogenesis, progression and therapy of human cancer. Mammalian immune regulator MCPIP1 (Zc3h12a) RNase acts as a novel suppressor of microRNA activity and biogenesis, suggesting the involvement of MCPIP1 in the alteration of microRNA biogenesis in tumorigenesis. Gene set enrichment analysis and functional assignment of microRNAs via enrichment analysis enable the prediction of microRNA activities from mRNA expression data by combining rank-based enrichment analysis and weighted evaluation of microRNA-mRNA interactions. MiR-124 and miR-203 function as tumor-suppressor microRNAs silenced by DNA methylation in hepatocellular carcinoma. Stella-induced DNA hypomethylation would confer the pathogenic function of DNA hypomethylation in cancer. Senescence-associated microRNA, miR-22, suppresses tumor growth and metastasis in vivo in a murine breast cancer model, and exosomal senescence-associated microRNA may affect the tumor microenvironment. The therapeutic potential of microRNAs for preventing and treating lung cancer using the Kras(LSL-G12D/+);p53(LSL-R172H/+)mouse model suggests that miR-34 may be useful in sensitizing tumors to other conventional therapeutics. MiR-1 and miR-133a cluster may function as tumor suppressors regulating novel pathways in human cancers. The down-regulation of miR-148a is implicated in invasion of gastric cancer, while high miR-21 expression in colorectal cancer is associated with poor survival. Neutral sphingomyelinase 2 regulates exosomal microRNA secretion and promotes angiogenesis within the tumor microenvironment as well as metastasis; in particular, the exosomal miR-210 secretion by neutral sphingomyelinase 2 confers the formation of the tumor vessel network.

  10. TaqMan real-time reverse transcription-PCR assay for universal detection and quantification of avian hepatitis E virus from clinical samples in the presence of a heterologous internal control RNA.

    PubMed

    Troxler, Salome; Marek, Ana; Prokofieva, Irina; Bilic, Ivana; Hess, Michael

    2011-04-01

    Avian hepatitis E virus (HEV) isolates could be separated into at least three genotypes. In this study, the development of the first duplex TaqMan real-time reverse transcription-PCR (RT-PCR) assay for detection and quantification of avian HEV is presented. Primers and probes binding within relatively conserved open reading frame 3 (ORF3) were designed. Tenfold dilution series of in vitro-transcribed avian HEV RNA were used as the standard for quantification. A 712-bp region of the green fluorescent protein gene was transcribed in vitro and used as a heterologous internal control for both RNA isolation and real-time RT-PCR. The duplex real-time RT-PCR for avian HEV had an efficiency of 1.04, a regression squared value of 0.996, and a sensitivity of approximately 3.6 × 10(3) copies per reaction mixture when in vitro-transcribed RNA was used as the template. The presence of in vitro-transcribed heterologous internal control RNA did not affect amplification of avian HEV RNA compared to that achieved by the single assay. The sensitivity of the real-time RT-PCR assay was comparable to that of conventional RT-PCR, and it was shown to be highly specific, as tissues from uninfected chickens, mammalian HEVs, and other viral genomes did not produce positive signals. All tested field samples with virus belonging to different avian HEV genotypes were successfully detected with this new duplex TaqMan real-time RT-PCR assay.

  11. Locating and quantifying ceramic body armor impact forces on a compliant torso using acceleration mapping

    NASA Astrophysics Data System (ADS)

    Cardi, Adam A.; Adams, Douglas E.; Walsh, Shawn

    2006-03-01

    This research experimentally implements a new method to identify the location and magnitude of a single impulsive excitation to ceramic body armor, which is supported on a compliant torso. The method could easily be extended to other flexibly supported components that undergo rigid body dynamics. Impact loads are identified in two steps. First, the location of the impact force is determined from time domain acceleration responses by comparing them to an array of reference acceleration time histories. Then based on the estimated location, reference frequency response functions are used to reconstruct the input force in the frequency domain through a least squares inverse problem. Experimental results demonstrate the validity of this method at both low energy excitations, which are produced by a medium modally-tuned impact hammer, and at high energy excitations, which are produced by dropping rods with masses up to 0.6 kilograms from a height of 2 meters. The maximum error in the estimated location or magnitude for the low energy excitations on the 10 cm square ceramic body armor was 7.07 mm with an average error of 1.09 mm. In comparing the estimated force for the low energy excitations to the force recorded by the transducer in the modal impact hammer, the maximum error in the predicted force amplitude was 6.78 percent and the maximum error in the predicted impulse was 6.44 percent. For the high energy excitations, which produced accelerations at the measurement locations up to 50 times greater than that of the low energy excitations, the maximum error in the predicted location of the input force was 15 mm with an average error of 6.64 mm. There was no force transducer to capture the input force on the body armor from the rod, but from non-energy-dissipative projectile motion equations the validity of the solutions was confirmed by comparing the impulses.

  12. Development of refractory armored silicon carbide by infrared transient liquid phase processing

    NASA Astrophysics Data System (ADS)

    Hinoki, Tatsuya; Snead, Lance L.; Blue, Craig A.

    2005-12-01

    Tungsten (W) and molybdenum (Mo) were coated on silicon carbide (SiC) for use as a refractory armor using a high power plasma arc lamp at powers up to 23.5 MW/m 2 in an argon flow environment. Both tungsten powder and molybdenum powder melted and formed coating layers on silicon carbide within a few seconds. The effect of substrate pre-treatment (vapor deposition of titanium (Ti) and tungsten, and annealing) and sample heating conditions on microstructure of the coating and coating/substrate interface were investigated. The microstructure was observed by scanning electron microscopy (SEM) and optical microscopy (OM). The mechanical properties of the coated materials were evaluated by four-point flexural tests. A strong tungsten coating was successfully applied to the silicon carbide substrate. Tungsten vapor deposition and pre-heating at 5.2 MW/m 2 made for a refractory layer containing no cracks propagating into the silicon carbide substrate. The tungsten coating was formed without the thick reaction layer. For this study, small tungsten carbide grains were observed adjacent to the interface in all conditions. In addition, relatively large, widely scattered tungsten carbide grains and a eutectic structure of tungsten and silicon were observed through the thickness in the coatings formed at lower powers and longer heating times. The strength of the silicon carbide substrate was somewhat decreased as a result of the processing. Vapor deposition of tungsten prior to powder coating helped prevent this degradation. In contrast, molybdenum coating was more challenging than tungsten coating due to the larger coefficient of thermal expansion (CTE) mismatch as compared to tungsten and silicon carbide. From this work it is concluded that refractory armoring of silicon carbide by Infrared Transient Liquid Phase Processing is possible. The tungsten armored silicon carbide samples proved uniform, strong, and capable of withstanding thermal fatigue testing.

  13. The Impacts of Armoring Our Deltas: Mapping and Modeling Large-Scale Deltaplain Aggradation

    NASA Astrophysics Data System (ADS)

    Overeem, I.; Higgins, S.; Syvitski, J. P.; Kettner, A. J.; Brakenridge, R.

    2014-12-01

    Humans have hardened land-water boundaries in almost every delta they live on. Engineering includes stabilizing and embanking channels to protect from river floods, building dikes around islands and emerging bars to reclaim land, and putting up sea walls to protect from waves and storm surges. These measures aim to reduce the exchange of water and sediment between the distributary delta channel network and the adjacent deltaplain. To first order, armoring of deltas results in net elevation loss of the floodplain, due to subsidence, compaction and reduced aggradation. Here, we ask what are the mechanisms of aggradation in 'armored' deltas? How do aggradation patterns compare to more natural depositional patterns? We analyze 2-week period aggregates of MODIS satellite data from 2000 onwards to map inundation patterns due to irrigation, river floods and storm surges for selected deltas. Using a MODIS band-ratio, we assess relative concentrations of suspended sediment in stagnant water on the floodplains. In addition, we use a simple approach to route sediment through the delta distributary network based on the relative channel geometries. A depositional process model then calculates cross-channel sediment flux as an exponential decay function, and determines sediment deposition over inundated areas. Stacked inundation maps show vast areas of deltaplains have flooded between 2000-2014, despite armoring channels with dikes, and coastlines with seawalls. Flooding is caused by overtopping of levees and more rarely by breaching and in those latter cases the flooded areas are often locally constrained. In Asian deltas, rice paddy irrigation with floodwater can be mapped even in the more distal floodplain. Our model predicts that inundated areas still receive significant amounts of fresh sediment, but that the pattern is more variable than in natural systems. Sparse in-situ observations of floodplain aggradation rates and storm surge deposits corroborate high, but localized

  14. Modeling a dynamically varying mixed sediment bed with erosion, deposition, bioturbation, consolidation, and armoring

    NASA Astrophysics Data System (ADS)

    Sanford, Lawrence P.

    2008-10-01

    Erosion and deposition of bottom sediments reflect a continual, dynamic adjustment between the fluid forces applied to a sediment bed and the condition of the bed itself. Erosion of fine and mixed sediment beds depends on their composition, their vertical structure, their disturbance/recovery history, and the biota that inhabit them. This paper presents a new one-dimensional (1D), multi-layer sediment bed model for simulating erosion and deposition of fine and mixed sediments subject to consolidation, armoring, and bioturbation. The distinguishing characteristics of this model are a greatly simplified first-order relaxation treatment for consolidation, a mud erosion formulation that adapts to both Type I and II erosion behavior and is based directly on observations, a continuous deposition formulation for mud that can mimic exclusive erosion and deposition behavior, and straightforward inclusion of bioturbation effects. Very good agreement with two laboratory data sets on consolidation effects is achieved by adjusting only the first-order consolidation rate r c. Full model simulations of three idealized cases based on upper Chesapeake Bay, USA observations are presented. In the mud only case, fluid stresses match mud critical stresses at maximum erosion. A consolidation lag results in higher suspended sediment concentrations after erosional events. Erosion occurs only during accelerating currents and deposition does not occur until just before slack water. In the mixed mud and sand case without bioturbation, distinct layers of high and low sand content form and mud suspension is strongly limited by sand armoring. In the mixed mud and sand case with bioturbation, suspended mud concentrations are greater than or equal to either of the other cases. Low surface critical stresses are mixed down into the bed, constrained by the tendency to return towards equilibrium. Sand layers and the potential for armoring of the bed develop briefly, but mix rapidly. This model offers

  15. ARMOR : A real time system for oceanic data intercomparison and combination

    NASA Astrophysics Data System (ADS)

    Larnicol, L.; Guinehut, S.; Garcia, G.; Le Traon, P. Y.

    2003-04-01

    The ARMOR system (Analyse de Routine Multivariée des Observations MERCATOR), developed in the frame of the French MERCATOR project, has the objective to implement and to operate ocean data analysis using altimetry, sea surface temperature and in-situ profiles, in real time over the whole ocean. Since January 2001, an ARMOR bulletin is published every week on the www mercator server (http://www.mercator.com.fr). It contains comparison both on the surface dynamic topography and on the surface velocities that allows us to firstly quantify the compatibility between the altimetry and the in-situ data and secondly to characterise their respective physical content (baroclinic, barotropic and ageotrophic part of the circulation). The second kind of analysis is the estimation of the 3D oceanic fields from the surface to 700 m via a multivariate interpolation of altimetry, SST and thermohaline profile. The methodology consists in the vertical projection of the remote sensing information giving synthetic profiles of temperature and salinity. The later are then combined with in-situ profiles using an objective analysis method. Finally, the two years of ARMOR analysis (January 2001 to January 2003) are used to assess the skill and limitation of the system. In particular, the accuracy of the remote sensing data projection is examined in terms of SST impact on the water column and in terms of barotropic correction impact for altimetric measurements. Moreover, comparison with the MERCATOR model simulations are also led in order to quantify the information provided by the model and its dynamic.

  16. Omnipotent RNA.

    PubMed

    Spirin, Alexander S

    2002-10-23

    The capability of polyribonucleotide chains to form unique, compactly folded structures is considered the basis for diverse non-genetic functions of RNA, including the function of recognition of various ligands and the catalytic function. Together with well-known genetic functions of RNA - coding and complementary replication - this has led to the concept of the functional omnipotence of RNA and the hypothesis that an ancient RNA world supposedly preceded the contemporary DNA-RNA-protein life. It is proposed that the Woese universal precursor in the ancient RNA world could be a cell-free community of mixed RNA colonies growing and multiplying on solid surfaces.

  17. RNA Crystallization

    NASA Technical Reports Server (NTRS)

    Golden, Barbara L.; Kundrot, Craig E.

    2003-01-01

    RNA molecules may be crystallized using variations of the methods developed for protein crystallography. As the technology has become available to syntheisize and purify RNA molecules in the quantities and with the quality that is required for crystallography, the field of RNA structure has exploded. The first consideration when crystallizing an RNA is the sequence, which may be varied in a rational way to enhance crystallizability or prevent formation of alternate structures. Once a sequence has been designed, the RNA may be synthesized chemically by solid-state synthesis, or it may be produced enzymatically using RNA polymerase and an appropriate DNA template. Purification of milligram quantities of RNA can be accomplished by HPLC or gel electrophoresis. As with proteins, crystallization of RNA is usually accomplished by vapor diffusion techniques. There are several considerations that are either unique to RNA crystallization or more important for RNA crystallization. Techniques for design, synthesis, purification, and crystallization of RNAs will be reviewed here.

  18. Tensile Stress-Strain Curves--III, Rolled Homogeneous Armor at a Strain Rate of 0.042 per second

    DTIC Science & Technology

    1977-06-01

    adhesive. The gage resistance is nominally 120 ohms and the nominal gage factor is 2.03. One strain gage pair measured the axial strain, the second gage...Proving Ground , MD, November 1976. AD #B0~6015L 8. G. E. Hauver, "The Alpha Phase Hugoniot of Rolled Homogeneous Armor ", BRL Memorandum Report No...1 i ’ ! .,: MEMORANDUM REPORT NO. 2760 "" ’ l TENSILE STRESS-STRAIN CURVES--Ill, ROLLED HOMOGENEOUS ARMOR AT A STRAIN RATE OF 0.42 S-l Ralph

  19. Relative Armor Penetration of Jacketed Lead, Solid Copper, Solid Brass, and Steel Core Bullets

    DTIC Science & Technology

    2012-11-30

    19a. NAME OF RESPONSIBLE PERSON Michael Courtney a. REPORT unclassified b . ABSTRACT unclassified c. THIS PAGE unclassified Same as Report (SAR...1 + (v/V50) b ). As described previously (Haight et al., 2012) the analysis method employed here differs from MIL-STD-662F, which is designed only...Übeyli, Mustafa, R. Orhan Yıldırım, and Bilgehan Ögel. On the comparison of the ballistic performance of steel and laminated composite armors. Materials & design 28, no. 4 (2007): 1257-1262. 4

  20. Simple go/no-go test for subcritical damage in body armor panels

    SciTech Connect

    Fisher, Jason; Chimenti, D. E.

    2011-06-23

    The development of a simple test for subcritical damage in body armor panels using pressure-sensitive dye-indicator film has been performed and demonstrated effective. Measurements have shown that static indicator levels are accurately reproduced in dynamic loading events. Impacts from hard blunt impactors instrumented with an accelerometer and embedded force transducer were studied. Reliable correlations between the indicator film and instrumented impact force are shown for a range of impact energies. Force and acceleration waveforms with corresponding indicator film results are presented for impact events onto damaged and undamaged panels. We find that panel damage can occur at impact levels far below the National Institute of Justice acceptance test standard.

  1. Simple No-Go Test for Subcritical Damage in Body Armor Panels

    NASA Astrophysics Data System (ADS)

    Fisher, Jason; Chimenti, D. E.

    2011-06-01

    The development of a simple test for subcritical damage in body armor panels using pressure-sensitive dye-indicator film has been performed and demonstrated effective. Measurements have shown that static indicator levels are accurately reproduced in dynamic loading events. Impacts from hard blunt impactors instrumented with an accelerometer and embedded force transducer were studied. Reliable correlations between the indicator film and instrumented impact force are shown for a range of impact energies. Force and acceleration waveforms with corresponding indicator film results are presented for impact events onto damaged and undamaged panels. We find that panel damage can occur at impact levels far below the National Institute of Justice acceptance test standard.

  2. Preliminary In Vivo Evaluation of a Hybrid Armored Vascular Graft Combining Electrospinning and Additive Manufacturing Techniques.

    PubMed

    Spadaccio, Cristiano; Nappi, Francesco; De Marco, Federico; Sedati, Pietro; Sutherland, Fraser W H; Chello, Massimo; Trombetta, Marcella; Rainer, Alberto

    2016-01-01

    In this study, we tested in vivo effectiveness of a previously developed poly-l-lactide/poly-ε-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings.

  3. US Army Armor Reference Data in Three Volumes. Volume I. The Army Division.

    DTIC Science & Technology

    1981-01-01

    Platoon , Armored Cavalry Platoon , Scout Platoon ............................................................. 628 2. Characteristics of Illumination Means...R 1S5(s ok 2 SPA (Cook) )Dvr) R 1 PFC (Cook) R *Mounts TOE cal .50 on ring mount. **Towed by 2h5-ton trucks on shutle basis. COMMUNICATION PLATOON ... PLATOON HEADQUARTERS \\ / RADIO SECTION 2A/SEVRK-38 AN/VRC-64 AN/GRA,39 AN/VSC-3 2 AN/PRC-77 AN/VRC-49 1SEC/KW-7 TSEC/KY-38 TSEC/KY-38 I MSG JTac Comm

  4. High Strength Glass Second Source Qualification to Composite Armor Specification MIL-L-46197(MR)

    DTIC Science & Technology

    1992-04-01

    L-46197 (MR). The Owens Corning Fiberglass (OCF) S-2 glass woven roving product has set the standard for this application to structural armor. The...HIARTMAN. 1). R. liallistc Penetration of S 2 Glass L~aminates S-2 Glass I-iber Technical Paper. Owens Corning Fiberglass. I I 1ASKLI.. W E. Spall...Materials Marketing. Owens Corning F’iberglass- Toledo. O1l, 416𔄃 SR and RI1 Gla" Chemical Composition. Vetrotex Data Sheet. IM11 04-02-2 6

  5. Determination of influence factors and accident rates for the Armored Tractor/Safe Secure Trailer

    SciTech Connect

    Phillips, J.S.; Clauss, D.B.; Blower, D.F.

    1994-04-01

    Operating environments, such as road type, road location, and time of day, play an important role in the observed accident rates of heavy trucks used in general commerce. These same factors influence the accident rate of the Armored Tractor/Safe Secure Trailer (AT/SST) used by the Department of Energy to transport hazardous cargos within the continental United States. This report discusses the development of accident rate influence factors. These factors, based on heavy trucks used in general commerce, are used to modify the observed overall AT/SST accident rate to account for the different operating environments.

  6. Impact of hydrograph form on bedload transport processes in armored channels

    NASA Astrophysics Data System (ADS)

    Kenworthy, M.; Yager, E.; Yarnell, S. M.

    2015-12-01

    Nearly all channels experience unsteady flows, from gradually varying snowmelt driven hydrographs to rapidly changing rain driven or regulated hydrographs. Despite this, the impacts of hydrograph form on bedload transport processes remain poorly understood. A set of flume experiments was conducted at the University of Idaho's Stream Lab to investigate whether hydrograph form (rapid vs gradual changes in flow) alters transport rates and mobile grain sizes for a given discharge as well as armor persistence and total transport volume during a high flow event. Prior to experiments the flume was run to equilibrium with limited sediment feed to armor the bed. Experiments included four steady state runs and nine hydrograph runs that used five different hydrograph forms. The rate of change in flow between time-steps varied in the hydrographs but minimum and peak flows and total estimated transport capacity were held constant. Initial data analysis suggests that hydrograph form does indeed impact total transport volumes, transport rates, and transported grain sizes. More rapidly changing hydrographs transported a larger total volume of sediment and had greater transport rates at peak flow than hydrographs with slower rates of change. All hydrographs displayed counter-clockwise hysteresis in transport rates with the exception of the most gradually varying run. More rapidly changing hydrographs had coarser bedload material on the rising limb but finer bedload material on the falling limb compared the same flow in more gradually changing hydrographs. Many of these observations may be linked to more significant armor loss promoted by more rapid changes in flow. On the rising limb, rapid changes in flow may increase the unsteady component of shear stress to mobilize larger grains and greater volumes of sediment over short durations compared to the effects of gradual flow increases. This has the potential to destabilize the armor surface and further mobilize surface and

  7. Armored Family of Vehicles (AFV) Automation and Communication. Resource Management Plan (ACRMP). Phase 1. Volume 15.

    DTIC Science & Technology

    1987-09-01

    BCE S 7 xi TRAINING U 8 XII FEA SPTG DOC S .% 9,10 Xill TECH ASSESSMENT S U . XIV LIGHT FORCES S 11 XV CRMP U XVI ACRONYMS/ABBR U (ITt 7 - ; 1 T1’ l...development, and producto n of the AFV n accordance with the AFV requirement and contractual baseline. 3.14 AFV ACRMP I SEPTEMBER 87 ,p VOLUME XV, CI...SUMMARY THE ARMOR’ED FAMILY OF VEHICLES SYSTEM OVERVI EW - CHASSIS: HEV MDI7I LIGHT SUB- TANK IFV LOSAD HWTR LO SAPPER LOSAT REARM NBCRSjMS RECON CEM

  8. RNA helicases

    PubMed Central

    Owttrim, George W.

    2013-01-01

    Similar to proteins, RNA molecules must fold into the correct conformation and associate with protein complexes in order to be functional within a cell. RNA helicases rearrange RNA secondary structure and RNA-protein interactions in an ATP-dependent reaction, performing crucial functions in all aspects of RNA metabolism. In prokaryotes, RNA helicase activity is associated with roles in housekeeping functions including RNA turnover, ribosome biogenesis, translation and small RNA metabolism. In addition, RNA helicase expression and/or activity are frequently altered during cellular response to abiotic stress, implying they perform defined roles during cellular adaptation to changes in the growth environment. Specifically, RNA helicases contribute to the formation of cold-adapted ribosomes and RNA degradosomes, implying a role in alleviation of RNA secondary structure stabilization at low temperature. A common emerging theme involves RNA helicases acting as scaffolds for protein-protein interaction and functioning as molecular clamps, holding RNA-protein complexes in specific conformations. This review highlights recent advances in DEAD-box RNA helicase association with cellular response to abiotic stress in prokaryotes. PMID:23093803

  9. Influence of the Internalization Pathway on the Efficacy of siRNA Delivery by Cationic Fluorescent Nanodiamonds in the Ewing Sarcoma Cell Model

    PubMed Central

    Alhaddad, Anna; Durieu, Catherine; Dantelle, Géraldine; Le Cam, Eric; Malvy, Claude; Treussart, François; Bertrand, Jean-Rémi

    2012-01-01

    Small interfering RNAs (siRNAs) are powerful tools commonly used for the specific inhibition of gene expression. However, vectorization is required to facilitate cell penetration and to prevent siRNA degradation by nucleases. We have shown that diamond nanocrystals coated with cationic polymer can be used to carry siRNAs into Ewing sarcoma cells, in which they remain traceable over long periods, due to their intrinsic stable fluorescence. We tested two cationic polymers, polyallylamine and polyethylenimine. The release of siRNA, accompanied by Ewing sarcoma EWS-Fli1 oncogene silencing, was observed only with polyethylenimine. We investigated cell penetration and found that the underlying mechanisms accounted for these differences in behavior. Using drugs selectively inhibiting particular pathways and a combination of fluorescence and electronic microscopy, we showed that siRNA gene silencing occurred only if the siRNA:cationic nanodiamond complex followed the macropinocytosis route. These results have potential implications for the design of efficient drug-delivery vectors. PMID:23284935

  10. A 9-nt segment of a cellular mRNA can function as an internal ribosome entry site (IRES) and when present in linked multiple copies greatly enhances IRES activity

    PubMed Central

    Chappell, Stephen A.; Edelman, Gerald M.; Mauro, Vincent P.

    2000-01-01

    This study addresses the properties of a newly identified internal ribosome entry site (IRES) contained within the mRNA of the homeodomain protein Gtx. Sequential deletions of the 5′ untranslated region (UTR) from either end did not define distinct IRES boundaries; when five nonoverlapping UTR fragments were tested, four had IRES activity. These observations are consistent with other cellular IRES analyses suggesting that some cellular IRESes are composed of segments (IRES modules) that independently and combinatorially contribute to overall IRES activity. We characterize a 9-nt IRES module from the Gtx 5′ UTR that is 100% complementary to the 18S rRNA at nucleotides 1132–1124. In previous work, we demonstrated that this mRNA segment could be crosslinked to its complement within intact 40S subunits. Here we show that increasing the number of copies of this IRES module in the intercistronic region of a dicistronic mRNA strongly enhances IRES activity in various cell lines. Ten linked copies increased IRES activity up to 570-fold in Neuro 2a cells. This level of IRES activity is up to 63-fold greater than that obtained by using the well characterized encephalomyocarditis virus IRES when tested in the same assay system. When the number of nucleotides between two of the 9-nt Gtx IRES modules was increased, the synergy between them decreased. In light of these findings, we discuss possible mechanisms of ribosome recruitment by cellular mRNAs, address the proposed role of higher order RNA structures on cellular IRES activity, and suggest parallels between IRES modules and transcriptional enhancer elements. PMID:10677496

  11. Placoderms (Armored Fish): Dominant Vertebrates of the Devonian Period

    NASA Astrophysics Data System (ADS)

    Young, Gavin C.

    2010-05-01

    Placoderms, the most diverse group of Devonian fishes, were globally distributed in all habitable freshwater and marine environments, like teleost fishes in the modern fauna. Their known evolutionary history (Early Silurian-Late Devonian) spanned at least 70 million years. Known diversity (335 genera) will increase when diverse assemblages from new areas are described. Placoderms first occur in the Early Silurian of China, but their diversity remained low until their main evolutionary radiation in the Early Devonian, after which they became the dominant vertebrates of Devonian seas. Most current placoderm data are derived from the second half of the group's evolutionary history, and recent claims that they form a paraphyletic group are based on highly derived Late Devonian forms; 16 shared derived characters are proposed here to support placoderm monophyly. Interrelationships of seven placoderm orders are unresolved because Silurian forms from China are still poorly known. The relationship of placoderms to the two major extant groups of jawed fishes—osteichthyans (bony fishes) and chondrichthyans (cartilaginous sharks, rays, and chimaeras)—remains uncertain, but the detailed preservation of placoderm internal braincase structures provides insights into the ancestral gnathostome (jawed vertebrate) condition. Placoderms provide the most complex morphological and biogeographic data set for the Middle Paleozoic; marked discrepancies in stratigraphic occurrence between different continental regions indicate strongly endemic faunas that were probably constrained by marine barriers until changes in paleogeography permitted range enlargement into new areas. Placoderm distributions in time and space indicate major faunal interchange between Gondwana and Laurussia near the Frasnian-Famennian boundary; closure of the Devonian equatorial ocean is a possible explanation.

  12. Process of infection of armored scale insects (Diaspididae) by an entomopathogenic Cosmospora sp.

    PubMed

    Mauchline, Nicola; Hallett, Ian; Hill, Garry; Casonato, Seona

    2011-09-01

    Several species in the fungal genus Cosmospora (synonym Nectria) (anamorph Fusarium) are specialist entomopathogens of armored scale insects (Diaspididae), known to cause periodic epizootics in host populations. Inconsistent mortality rates recorded under laboratory conditions prompted a study into the process of infection of armored scale insects by this fungus. Scale insect mortality following exposure to a Cosmospora sp. (Culture Collection Number: CC89) from New Zealand was related to insect age, with reproductively mature insects having a significantly higher infection rate than immature insects. Examination using scanning electron microscopy found no evidence that the fungus penetrated directly through the wax test (cap) of the scale insect or through the un-lifted interface between the test and the substrate on which the insect resided. However, fungal hyphae were observed growing beneath the test when the test of the reproductively mature insect lifted away from the substrate for the purpose of releasing crawlers, the mobile pre-settled juveniles. Once the hyphae of CC89 advanced under the test, germ-tubes readily penetrated the insect body through a number of natural openings (e.g. spiracles, vulva, stylet), with mycosis observed within seven days after inoculation. Direct penetration through the cuticle of the scale insect was not observed.

  13. Ritualized fighting and biological armor: the impact mechanics of the mantis shrimp's telson.

    PubMed

    Taylor, J R A; Patek, S N

    2010-10-15

    Resisting impact and avoiding injury are central to survival in situations ranging from the abiotic forces of crashing waves to biotic collisions with aggressive conspecifics. Although impacts and collisions in biology are ubiquitous, most studies focus on the material properties of biological structures under static loading. Here, we examine the mechanical impact properties of the mantis shrimp's telson, a piece of abdominal armor that withstands repeated, intense impacts from the potent hammer-like appendages used by conspecifics during ritualized fighting. We measured the coefficient of restitution, an index of elasticity, of the telson and compared it with that of an adjacent abdominal segment that is not impacted. We found that the telson behaves more like an inelastic punching bag than an elastic trampoline, dissipating 69% of the impact energy. Furthermore, although the abdominal segment provides no mechanical correlates with size, the telson's coefficient of restitution, displacement and impact duration all correlate with body size. The telson's mineralization patterns were determined through micro-CT (Computed Tomography) and correspond to the mechanical behavior of the telson during impact. The mineralized central region of the telson 'punched' inward during an impact whereas the surrounding areas provided elasticity owing to their reduced mineralization. Thus, the telson effectively dissipates impact energy while potentially providing the size-related information crucial to its role in conspecific assessment. This study reveals the mechanical infrastructure of impact resistance in biological armor and opens a new window to the biomechanical underpinnings of animal behavior and assessment.

  14. The evolution of body armor in mammals: plantigrade constraints of large body size.

    PubMed

    Lovegrove, B G

    2001-07-01

    Predictions associated with opposing selection generating minimum variance in basal metabolic rate (BMR) in mammals at a constrained body mass (CBM; 358 g) were tested. The CBM is presumed to be associated with energetic constraints linked to predation and variable resources at intermediate sizes on a logarithmic mass scale. Opposing selection is thought to occur in response to energetic constraints associated with predation and unpredictable resources. As body size approaches and exceeds the CBM, mammals face increasing risks of predation and daily energy requirements. Fast running speeds may require high BMRs, but unpredictable and low resources may select for low BMRs, which also reduce foraging time and distances and thus predation risks. If these two selection forces oppose each other persistently, minimum BMR variance may result. However, extreme BMR outliers at and close to the CBM should be indicative of unbalanced selection and predator avoidance alternatives (escapers vs. defenders), and may therefore provide indirect support for opposing selection. It was confirmed that body armor in defenders evolves at and above the CBM, and armored mammals had significantly lower BMRs than their nonarmored counterparts. However, analyses comparing the BMR of escapers--the fastest nonarmored runners (Lagomorpha)--with similar-sized counterparts were inconclusive and were confounded by limb morphology associated with speed optimization. These analyses suggest that the risks and costs of predation and the speed limitations of the plantigrade foot may constrain the evolution of large body sizes in plantigrade mammals.

  15. Fragmentation of armor piercing steel projectiles upon oblique perforation of steel plates

    NASA Astrophysics Data System (ADS)

    Paris, V.; Weiss, A.; Vizel, A.; Ran, E.; Aizik, F.

    2012-08-01

    In this study, a constitutive strength and failure model for a steel core of a14.5 mm API projectile was developed. Dynamic response of a projectile steel core was described by the Johnson-Cook constitutive model combined with principal tensile stress spall model. In order to obtain the parameters required for numerical description of projectile core material behavior, a series of planar impact experiments was done. The parameters of the Johnson-Cook constitutive model were extracted by matching simulated and experimental velocity profiles of planar impact. A series of oblique ballistic experiments with x-ray monitoring was carried out to study the effect of obliquity angle and armor steel plate thickness on shattering behavior of the 14.5 mm API projectile. According to analysis of x-ray images the fragmentation level increases with both steel plate thickness and angle of inclination. The numerical modeling of the ballistic experiments was done using commercial finite element code, LS-DYNA. Dynamic response of high hardness (HH) armor steel was described using a modified Johnson-Cook strength and failure model. A series of simulations with various values of maximal principal tensile stress was run in order to capture the overall fracture behavior of the projectile's core. Reasonable agreement between simulated and x-ray failure pattern of projectile core has been observed.

  16. Structure and mechanical behaviors of protective armored pangolin scales and effects of hydration and orientation.

    PubMed

    Liu, Z Q; Jiao, D; Weng, Z Y; Zhang, Z F

    2016-03-01

    As natural flexible dermal armor, pangolin scales provide effective protection against predatory threats and possess other notable properties such as anti-adhesion and wear-resistance. In this study, the structure, mechanical properties, deformation and damage behaviors of pangolin scales were systematically investigated with the effects of hydration and orientation evaluated. The scales are divided into three macro-layers constituted by overlapping keratin tiles with distinct lamellar arrangements which are further composed of lower-ordered lamellae. Both hardness and strength are significantly decreased by hydration; while the plasticity is markedly improved concomitantly, and as such, the mechanical damages are mitigated. The tensile strength invariably approximates to one third of hardness in value. The tensile deformation is dominated by lamellae stretching and pulling out under wet condition, which is distinct from the trans-lamellar fracture in dry samples. The compressive behaviors are featured by pronounced plasticity in both dry and wet scales; and notable strain-hardening capacity is introduced by hydration, especially along the thickness direction wherein kinking occurs. Inter-lamellar cracking is effectively alleviated in wet samples compared with the dry ones and both of them deform by macroscopic buckling. This study may help stimulate possible inspiration for the design of high-performance synthetic armor materials by mimicking pangolin scales.

  17. ANALYSES OF VARIOUS DAMAGE MECHANISMS IN TRANSPARENT ARMOR SUBJECT TO PROJECTILE IMPACT

    SciTech Connect

    Lai, Canhai; Sun, Xin; Templeton, Douglas W.

    2009-01-23

    Design and manufacturing of transparent armor have been historically carried out using experimental approaches. In this study, we use advanced computational modeling tools to study the various stress components during the impact event and to identify the different crack/damage driving mechanisms for the different cracking patterns. Experimentally observed damage patterns for a thick glass laminate under fragmentation simulation projectile (FSP) impact are used to compare with the modeling results. AHPCRC developed modeling software EPIC’06 [1] is used in predicting the penetration resistance of transparent armor systems. It is found that a 1-parameter single state model can be used to predict the impact penetration depth with relatively good accuracy. In addition, hoop stress and circumferential stresses are found to produce ripple cracks, needle cracks and radial cracks. It is also found that a region of high hoop stress and circumferential stress is produced by the impact at the back side of the target plate, causing the floret damage region possibly leading to higher penetration depth for thinner laminates or higher velocity impact.

  18. Constitutive Modeling of Hot Deformation Behavior of High-Strength Armor Steel

    NASA Astrophysics Data System (ADS)

    Bobbili, Ravindranadh; Madhu, Vemuri

    2016-05-01

    The hot isothermal compression tests of high-strength armor steel under a wide range of deformation temperatures (1100-1250 °C) and strain rates of (0.001-1/s) were performed. Based on the experimental data, constitutive models were established using the original Johnson-Cook (JC) model, modified JC model, and strain-compensated Arrhenius model, respectively. The modified JC model considers the coupled effects of strain hardening, strain rate hardening, and thermal softening. Moreover, the prediction accuracy of these developed models was determined by estimating the correlation coefficient ( R) and average absolute relative error (AARE). The results demonstrate that the flow behavior of high-strength armor steel is considerably influenced by the strain rate and temperature. The original JC model is inadequate to provide good description on the flow stress at evaluated temperatures. The modified JC model and strain-compensated Arrhenius model significantly enhance the predictability. It is also observed from the microstructure study that at low strain rates (0.001-0.01/s) and high temperatures (1200-1250 °C), a typical dynamic recrystallization (DRX) occurs.

  19. Gene expression as a circular process: cross-talk between transcription and mRNA degradation in eukaryotes; International University of Andalusia (UNIA) Baeza, Spain.

    PubMed

    Collart, Martine A; Reese, Joseph C

    2014-01-01

    Studies on the regulation of gene expression in eukaryotes in the past 20 years have consistently revealed increasing levels of complexity. Thirty years ago it seemed that we had understood the basic principles of gene regulation in eukaryotes. It was thought that regulation of transcription was the first and most important stage at which gene expression was regulated, and transcriptional regulation was considered to be very simple, with DNA-binding activators and repressors talking to the basic transcription machinery. This simple model was overthrown when it became clear that other stages of gene expression are also highly regulated. More recently, other dogmas have started to collapse. In particular, the idea that a linkage between the different steps in gene expression is restricted to processes ongoing in the same compartment has fallen out of favor. It is now evident that functional and physical linkage occurs in eukaryotes. We know that factors contributing to transcription in the nucleus can be found in the cytoplasm, and that RNA binding proteins that contribute to RNA decay in the cytoplasm are present in the nucleus. However, shuttling of such factors between nucleus and cytoplasm has traditionally been thought to serve a simple regulatory purpose, for instance, to avoid untimely activation of a transcription factor in the nucleus. Alternatively, it was thought to be necessary to recruit RNA binding proteins to the relevant RNAs. The notion that is now emerging is that factors thought to have evolved to specialize in regulating a single step of gene regulation in one cellular compartment may be contributing to the regulation of mRNAs at multiple steps along the lifecycle of an mRNA.

  20. 75 FR 78268 - Draft NIJ Selection and Application Guide to Ballistic-Resistant Body Armor for Law Enforcement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-15

    ... Law Enforcement, Corrections, and Public Safety AGENCY: National Institute of Justice. ACTION: Notice of Draft NIJ Selection and Application Guide to Ballistic-Resistant Body Armor for Law Enforcement... for Law Enforcement, Corrections, and Public Safety.'' The opportunity to provide comments on...

  1. Effect of PTA Hardfaced Interlayer Thickness on Ballistic Performance of Shielded Metal Arc Welded Armor Steel Welds

    NASA Astrophysics Data System (ADS)

    Balakrishnan, M.; Balasubramanian, V.; Madhusudhan Reddy, G.

    2013-03-01

    Ballistic performance of armor steel welds is very poor due to the usage of low strength and low hardness austenitic stainless steel fillers, which are traditionally used to avoid hydrogen induced cracking. In the present investigation, an attempt has been made to study the effect of plasma transferred arc hardfaced interlayer thickness on ballistic performance of shielded metal arc welded armor steel weldments. The usefulness of austenitic stainless steel buttering layer on the armor grade quenched and tempered steel base metal was also considered in this study. Joints were fabricated using three different thickness (4, 5.5, and 7 mm) hardfaced middle layer by plasma transferred arc hardfacing process between the top and bottom layers of austenitic stainless steel using shielded metal arc welding process. Sandwiched joint, in addition with the buttering layer served the dual purpose of weld integrity and ballistic immunity due to the high hardness of hardfacing alloy and the energy absorbing capacity of soft backing weld deposits. This paper will provide some insight into the usefulness of austenitic stainless steel buttering layer on the weld integrity and plasma transferred arc hardfacing layer on ballistic performance enhancement of armor steel welds.

  2. Strategic Research Institute--first international siRNA conference. Prospect for new therapeutics and commercial opportunities for pharma and biotech. 24-25 March 2003, LaJolla, CA, USA.

    PubMed

    Xu, Jing

    2003-05-01

    Small interfering RNAs (siRNAs), with their power to selectively silence genes, have gained much attention from biotech and pharmaceutical companies and investors. Key players in the field, from innovative biotech start-ups to big pharmaceutical companies, gathered at Strategic Research Institute's First International siRNA conference in the scenic Hilton La Jolla Torrey Pines. Topics addressed ranged from the latest technology advances and applications of RNA interference (RNAi) in drug discovery, to critical business issues such as intellectual property portfolio strategy and market prospects. While RNAi is indisputably accepted as a powerful tool in target validation and functional genomics, the concept of an siRNA drug is still viewed by big pharma companies as next-generation therapeutics. Yet challenges seem tractable. Several companies, such as Ribozyme Pharmaceuticals Inc, Alnylam Pharmaceuticals and Intradigm Corp, are working hard to prove that the bigger companies are being too conservative. The conference provided a clear vision of RNAi in drug discovery today, its potential and remaining challenges.

  3. Material Modeling and Ballistic-Resistance Analysis of Armor-Grade Composites Reinforced with High-Performance Fibers

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Glomski, P. S.; He, T.; Arakere, G.; Bell, W. C.; Cheeseman, B. A.

    2009-12-01

    A new ballistic material model for 0°/90° cross-plied oriented ultra-high molecular weight (UHMW) polyethylene fiber-based armor-grade composite laminates has been constructed using open-literature data for the fiber and polymeric-matrix material properties and the general experimental/field-test observations regarding the deformation and failure modes in these types of materials. The present model is an extension of our recently developed unit cell-based ballistic material model for the same class of composites (M. Grujicic, G. Arakere, T. He,W.C. Bell, B. A. Cheeseman, C.-F. Yen, and B. Scott, A Ballistic Material Model for Cross-Plied Unidirectional Ultra-High Molecular-Weight Polyethylene Fiber-reinforced Armor-Grade Composites, Mater. Sci. Eng, A 2008, 498(1-2), p 231-241) which was found to be physically sound, but computationally not very efficient. The present model is constructed in such a way that it can be readily integrated into commercial finite element programs like ANSYS/Autodyn (ANSYS/Autodyn version 11.0, User Documentation, Century Dynamics Inc., a subsidiary of ANSYS Inc., 2007), as a User Material Subroutine. To validate the model, a series of transient nonlinear dynamics computational analyses of the transverse impact of armor-grade composite laminates with two types of bullets/projectiles is carried out and the computational results compared with their experimental counterparts. Relatively good agreement is found between the experiment and the computational analysis relative to: (a) the success of the armor panels of different areal densities in defeating the bullets at different initial bullet velocities; (b) postmortem spatial distribution of the damage modes and the extents within the panels; (c) the temporal evolution of the armor-panel back-face bulge; and (d) The existence of three distinct armor-penetration stages (i.e., an initial filament shearing/cutting dominated stage, an intermediate stage characterized by pronounced filament

  4. RNA genetics

    SciTech Connect

    Domingo, E. ); Holland, J.J. . Dept. of Biology); Ahlquist, P. . Dept. of Plant Pathology)

    1988-01-01

    This book contains the proceedings on RNA gentics: Variability of RNA genomes, Volume III. Topics covered include: High error rate, population equilibrium, and evolution of RNA replication systems; Influenza viruses; High rate of nutation and evolution; and Sequence space and quasi species distribution.

  5. RNA genetics

    SciTech Connect

    Domingo, E. ); Holland, J.J. . Dept. of Biology); Ahlquist, P. . Dept. of Plant Pathology)

    1988-01-01

    This book contains the proceedings on RNA genetics: RNA-directed virus replication Volume 1. Topics covered include: Replication of the poliovirus genome; Influenza viral RNA transcription and replication; and Relication of the reoviridal: Information derived from gene cloning and expression.

  6. A phylogenetic analysis of armored scale insects (Hemiptera: Diaspididae), based upon nuclear, mitochondrial, and endosymbiont gene sequences.

    PubMed

    Andersen, Jeremy C; Wu, Jin; Gruwell, Matthew E; Gwiazdowski, Rodger; Santana, Sharlene E; Feliciano, Natalie M; Morse, Geoffrey E; Normark, Benjamin B

    2010-12-01

    Armored scale insects (Hemiptera: Diaspididae) are among the most invasive insects in the world. They have unusual genetic systems, including diverse types of paternal genome elimination (PGE) and parthenogenesis. Intimate relationships with their host plants and bacterial endosymbionts make them potentially important subjects for the study of co-evolution. Here, we expand upon recent phylogenetic work (Morse and Normark, 2006) by analyzing armored scale and endosymbiont DNA sequences from 125 species of armored scale insect, represented by 253 samples and eight outgroup species. We used fragments of four different gene regions: the nuclear protein-coding gene Elongation Factor 1α (EF1α), the large ribosomal subunit (28S) rDNA, a mitochondrial region spanning parts of cytochrome oxidase I (COI) and cytochrome oxidase II (COII), and the small ribosomal subunit (16S) rDNA from the primary bacterial endosymbiont Uzinura diaspidicola. Maximum likelihood, and Bayesian analyses were performed producing highly congruent topological results. A comparison of two datasets, one with and one without missing data, found that missing data had little effect on topology. Our results broadly corroborate several major features of the existing classification, although we do not find any of the subfamilies, tribes or subtribes to be monophyletic as currently constituted. Using ancestral state reconstruction we estimate that the ancestral armored scale had the late PGE sex system, and it may as well have been pupillarial, though results differed between reconstruction methods. These results highlight the need for a complete revision of this family, and provide the groundwork for future taxonomic work in armored scale insects.

  7. The 5′ Leader of the mRNA Encoding the Marek's Disease Virus Serotype 1 pp14 Protein Contains an Intronic Internal Ribosome Entry Site with Allosteric Properties ▿

    PubMed Central

    Tahiri-Alaoui, Abdessamad; Matsuda, Daiki; Xu, Hongtao; Panagiotis, Panopoulos; Burman, Luke; Lambeth, Luke S.; Petherbridge, Lawrence; James, William; Mauro, Vincent; Nair, Venugopal

    2009-01-01

    We demonstrate the presence of a functional internal ribosome entry site (IRES) within the 5′ leader (designated 5L) from a variant of bicistronic mRNAs that encode the pp14 and RLORF9 proteins from Marek's disease virus (MDV) serotype 1. Transcribed as a 1.8-kb family of immediate-early genes, the mature bicistronic mRNAs have variable 5′ leader sequences due to alternative splicing or promoter usage. Consequently, the presence or absence of the 5L IRES in the mRNA dictates the mode of pp14 translation and leads to the production of two pp14 isoforms that differ in their N-terminal sequences. Real-time reverse transcription-quantitative PCR indicates that the mRNA variants with the 5L IRES is two to three times more abundant in MDV-infected and transformed cells than the mRNA variants lacking the 5L IRES. A common feature to all members of the 1.8-kb family of transcripts is the presence of an intercistronic IRES that we have previously shown to control the translation of the second open reading frame (i.e., RLORF9). Investigation of the two IRESs residing in the same bicistronic reporter mRNA revealed functional synergism for translation efficiency. In analogy with allosteric models in proteins, we propose IRES allostery to describe such a novel phenomenon. The functional implications of our findings are discussed in relation to host-virus interactions and translational control. PMID:19793814

  8. Quantitative Model of microRNA-mRNA interaction

    NASA Astrophysics Data System (ADS)

    Noorbakhsh, Javad; Lang, Alex; Mehta, Pankaj

    2012-02-01

    MicroRNAs are short RNA sequences that regulate gene expression and protein translation by binding to mRNA. Experimental data reveals the existence of a threshold linear output of protein based on the expression level of microRNA. To understand this behavior, we propose a mathematical model of the chemical kinetics of the interaction between mRNA and microRNA. Using this model we have been able to quantify the threshold linear behavior. Furthermore, we have studied the effect of internal noise, showing the existence of an intermediary regime where the expression level of mRNA and microRNA has the same order of magnitude. In this crossover regime the mRNA translation becomes sensitive to small changes in the level of microRNA, resulting in large fluctuations in protein levels. Our work shows that chemical kinetics parameters can be quantified by studying protein fluctuations. In the future, studying protein levels and their fluctuations can provide a powerful tool to study the competing endogenous RNA hypothesis (ceRNA), in which mRNA crosstalk occurs due to competition over a limited pool of microRNAs.

  9. NMR structure of a 4 × 4 nucleotide RNA internal loop from an R2 retrotransposon: Identification of a three purine–purine sheared pair motif and comparison to MC-SYM predictions

    PubMed Central

    Lerman, Yelena V.; Kennedy, Scott D.; Shankar, Neelaabh; Parisien, Marc; Major, Francois; Turner, Douglas H.

    2011-01-01

    The NMR solution structure is reported of a duplex, 5′GUGAAGCCCGU/3′UCACAGGAGGC, containing a 4 × 4 nucleotide internal loop from an R2 retrotransposon RNA. The loop contains three sheared purine–purine pairs and reveals a structural element found in other RNAs, which we refer to as the 3RRs motif. Optical melting measurements of the thermodynamics of the duplex indicate that the internal loop is 1.6 kcal/mol more stable at 37°C than predicted. The results identify the 3RRs motif as a common structural element that can facilitate prediction of 3D structure. Known examples include internal loops having the pairings: 5′GAA/3′AGG, 5′GAG/3′AGG, 5′GAA/3′AAG, and 5′AAG/3′AGG. The structural information is compared with predictions made with the MC-Sym program. PMID:21778280

  10. A new species of armored scale, Mycetaspis ailynaomi (Hemiptera, Diaspididae, Aspidiotinae), associated with Mammea americana L. (Malpighiales, Calophyllaceae) from Puerto Rico.

    PubMed

    Dones, Ramón A; Evans, Gregory A

    2011-01-01

    A new species of armored scale, Mycetaspis ailynaomi Dones and Evans is described and illustrated from specimens collected on mamey (Mammea americana) from Puerto Rico. A key to the species of Mycetaspis is provided.

  11. A new species of armored scale, Mycetaspis ailynaomi (Hemiptera, Diaspididae, Aspidiotinae), associated with Mammea americana L. (Malpighiales, Calophyllaceae) from Puerto Rico

    PubMed Central

    Dones, Ramón A.; Evans, Gregory A.

    2011-01-01

    Abstract A new species of armored scale, Mycetaspis ailynaomi Dones and Evans is described and illustrated from specimens collected on mamey (Mammea americana) from Puerto Rico. A key to the species of Mycetaspis is provided. PMID:21852924

  12. DNA barcodes for two scale insect families, mealybugs (Hemiptera: Pseudococcidae) and armored scales (Hemiptera: Diaspididae).

    PubMed

    Park, D-S; Suh, S-J; Hebert, P D N; Oh, H-W; Hong, K-J

    2011-08-01

    Although DNA barcode coverage has grown rapidly for many insect orders, there are some groups, such as scale insects, where sequence recovery has been difficult. However, using a recently developed primer set, we recovered barcode records from 373 specimens, providing coverage for 75 species from 31 genera in two families. Overall success was >90% for mealybugs and >80% for armored scale species. The G·C content was very low in most species, averaging just 16.3%. Sequence divergences (K2P) between congeneric species averaged 10.7%, while intra-specific divergences averaged 0.97%. However, the latter value was inflated by high intra-specific divergence in nine taxa, cases that may indicate species overlooked by current taxonomic treatments. Our study establishes the feasibility of developing a comprehensive barcode library for scale insects and indicates that its construction will both create an effective system for identifying scale insects and reveal taxonomic situations worthy of deeper analysis.

  13. Armored brain in patients with hydrocephalus after shunt surgery: review of the literatures.

    PubMed

    Taha, Mahmoud M

    2012-01-01

    Armored brain or chronic calcified subdural hematoma is a rare complication of cerebrospinal fluid diversion with few cases reported in the literature. Seventeen patients with this pathology have been published. A complete review of the literatures regarding this topic has been collected and discussed. The author also presents a 12- year old boy with triventricular hydrocephalus who had undergone ventriculoperitoneal medium pressure shunt system since birth. The patient presented to our clinic with a 2-year history of seizures. The patient was conscious and without neurological deficits on examination. Computed tomography of the brain showed bilateral high density mass with surface calcification. X ray skull and MRI confirmed the calcified subdural hematoma bilaterally. We preferred conservative treatment and the patient continued his antiepileptic treatment. At one year follow up, the patient had the same neurological state. The case highlights the importance of frequent follow up CT brain after shunt surgery.

  14. Expanding the Availability of Lightweight Aluminum Alloy Armor Plate Procured From Detailed Military Specifications

    DTIC Science & Technology

    2012-07-01

    A. Cassada TMS (The Minerals , Metals & Materials Society), 2012 541 Whereas armor plate specifications specify the acceptance characteristics of a...duralumin were utilized by the Germans in one year, primarily in airships [2]. Duralumin, which contained copper, manganese and magnesium as alloying...0.90 0.25 0.25 0.25 7.0-8.0 Titanium 0.15 0.2 0.1 0.02-0.10 0.2 0.15 0.15 0.1 0.06 Zirconium 0.10-0.25 0.08-0.16 0.08-0.15 Vanadium 0.05-0.15 0.05

  15. Finite Element Modeling of the Behavior of Armor Materials Under High Strain Rates and Large Strains

    NASA Astrophysics Data System (ADS)

    Polyzois, Ioannis

    For years high strength steels and alloys have been widely used by the military for making armor plates. Advances in technology have led to the development of materials with improved resistance to penetration and deformation. Until recently, the behavior of these materials under high strain rates and large strains has been primarily based on laboratory testing using the Split Hopkinson Pressure Bar apparatus. With the advent of sophisticated computer programs, computer modeling and finite element simulations are being developed to predict the deformation behavior of these metals for a variety of conditions similar to those experienced during combat. In the present investigation, a modified direct impact Split Hopkinson Pressure Bar apparatus was modeled using the finite element software ABAQUS 6.8 for the purpose of simulating high strain rate compression of specimens of three armor materials: maraging steel 300, high hardness armor (HHA), and aluminum alloy 5083. These armor materials, provided by the Canadian Department of National Defence, were tested at the University of Manitoba by others. In this study, the empirical Johnson-Cook visco-plastic and damage models were used to simulate the deformation behavior obtained experimentally. A series of stress-time plots at various projectile impact momenta were produced and verified by comparison with experimental data. The impact momentum parameter was chosen rather than projectile velocity to normalize the initial conditions for each simulation. Phenomena such as the formation of adiabatic shear bands caused by deformation at high strains and strain rates were investigated through simulations. It was found that the Johnson-Cook model can accurately simulate the behavior of body-centered cubic (BCC) metals such as steels. The maximum shear stress was calculated for each simulation at various impact momenta. The finite element model showed that shear failure first occurred in the center of the cylindrical specimen and

  16. Fabrication of High-Strength Lightweight Metals for Armor and Structural Applications

    DTIC Science & Technology

    2012-04-05

    AA5082. See Fig.3.        4. Friction Steer Welding ( FSW ) of ECAE+WR AA5083 was performed for thickness 0.25”. A  micro‐structural analysis detected (i...significant degradation of structure and properties,  fabrication of mono armor plates by ECAE+WR is the most desirable.  An additional R&D work is  necessary to reduce a heating effect of  FSW  and improve the weld uniformity.   

  17. Carbide-Free Bainitic Weld Metal: A New Concept in Welding of Armor Steels

    NASA Astrophysics Data System (ADS)

    Krishna Murthy, N.; Janaki Ram, G. D.; Murty, B. S.; Reddy, G. M.; Rao, T. J. P.

    2014-12-01

    Carbide-free bainite, a fine mixture of bainitic ferrite and austenite, is a relatively recent development in steel microstructures. Apart from being very strong and tough, the microstructure is hydrogen-tolerant. These characteristics make it well-suited for weld metals. In the current work, an armor-grade quenched and tempered steel was welded such that the fusion zone developed a carbide-free bainitic microstructure. These welds showed very high joint efficiency and ballistic performance compared to those produced, as per the current industrial practice, using austenitic stainless steel fillers. Importantly, these welds showed no vulnerability to cold cracking, as verified using oblique Y-groove tests. The concept of carbide-free bainitic weld metal thus promises many useful new developments in welding of high-strength steels.

  18. Tritium permeation experiment using a tungsten armored divertor-simulating module

    NASA Astrophysics Data System (ADS)

    Nakamura, H.; O'hira, S.; Shu, W.; Nishi, M.; Venhaus, T. J.; Causey, R. A.; Hyatt, D. R.; Willms, R. S.

    2000-12-01

    A first engineering type experiment for evaluation of tritium permeation rate through a tungsten armored divertor of a DT fusion machine was carried out using tritium plasma experimental (TPE) apparatus under the collaborative program between US-DOE and JAERI. A test module having a multi-layer structure (W:1 mm t, Cu:5 mm t and a cavity containing water pressurized at 2.2 MPa) was exposed to DT (D:T=2:1) plasma. Break-through of tritium permeation into the water was observed after 4 h of plasma exposure. The amount of tritium permeated was compared with permeation rates predicted by numerical simulation codes (TMAP4 and TPERM). Feasibility of the experimental system and procedures to predict the tritium permeation behavior was examined using the simulation codes.

  19. Preliminary In Vivo Evaluation of a Hybrid Armored Vascular Graft Combining Electrospinning and Additive Manufacturing Techniques

    PubMed Central

    Spadaccio, Cristiano; Nappi, Francesco; De Marco, Federico; Sedati, Pietro; Sutherland, Fraser W.H.; Chello, Massimo; Trombetta, Marcella; Rainer, Alberto

    2016-01-01

    In this study, we tested in vivo effectiveness of a previously developed poly-l-lactide/poly-ε-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings. PMID:26949333

  20. Biochemical responses, morphometric changes, genotoxic effects and CYP1A expression in the armored catfish Pterygoplichthys anisitsi after 15 days of exposure to mineral diesel and biodiesel.

    PubMed

    Arantes Felício, Andréia; Martins Parente, Thiago Estevam; Regina Maschio, Lucilene; Nogueira, Lílian; Rodrigues Venancio, Larissa Paola; de Freitas Rebelo, Mauro; Schlenk, Daniel; de Almeida, Eduardo Alves

    2015-05-01

    Despite being considered friendlier to the environment, biodiesel fuel can be harmful to aquatic organisms, especially when combined with petroleum diesel fuel. In this work we evaluated the effects of mineral diesel fuel containing increasing concentrations of biodiesel (5% and 20%, namely B5 and B20) and pure biodiesel (B100), at concentrations of 0.001 and 0.01mLL(-1), after 15 days of exposure, in armored catfish (Pterygoplichtys anisitsi). Toxicity tests were also performed to estimate LC50 values (96h) for each compound. Biotransformation enzymes [ethoxyresorufin-O-deethylase (EROD), and glutathione S-transferase (GST)] as well as oxidative stress markers (superoxide dismutase, SOD, catalase, CAT, glutathione peroxidase, GPx, and the level of lipid peroxidation) were measured in liver and gills after treatment. Genotoxic effects were also accessed in erythrocytes using the comet assay and by evaluating the frequency of micronuclei formation. Further, the mRNA of cytochrome P450 1A (CYP1A) was also measured in liver. Mortality was not observed even exposure to concentrations as high as 6.0mLL(-1). EROD and GST activities were increased after B5 and B20 treatments; however, CYP1A mRNA induction was not observed. SOD and CAT activities were decreased, but GPx was significantly higher for all treatments in gills. There were no significant changes in lipid peroxidation, but genotoxicity markers revealed that all treatments increased comet scores. Fuels B5 and B20 increased micronuclei frequency. Our results indicate that despite being less toxic, biodiesel may cause sublethal alterations in fish that may alter long term health.

  1. Iron Sappers Lead the Way: The 16th Engineer Battalion’s Support of 1st Armored Division in Southwest Asia

    DTIC Science & Technology

    1993-03-30

    limited value due to the availability of double impulse, blast resistant mines and the success of the tank plow. The GEMSS ( ground emplaced mine...34 Ironsides (Ansbach, Germany), 5 July 1991, p. 10. Headquarters, Phantom Brigade, 1st Armored Division. "DESERT SHIELD and DESERT STORM After Action...govemment agency. IRON SAPPERS LEAD THE WAY: THE 16TH ENGINEER BATTALION’S SUPPORT OF 1ST ARMORED DIVISION IN SOUTHWEST ASIA BY LIEUTENANT COLONEL

  2. One Tank, 31 Boxes of .50 Cal. and 11 Men: An Analysis of the Armor- Infantry Team in Korea, June 1950 - July 1952

    DTIC Science & Technology

    1989-06-02

    communist empire culminated in September of 1949. Early in the autumn of that year, the Soviet Union exploded its own atomic device and the second superpower...armor-infantry teams in tactical situations in a European context, FM 17-36, Infantry-Tank T examined the use of armor-infantry teams involved in...basic ingredients as its World War II predecessor. There was little need for change until the detonation by the Soviet Union of their own atomic device

  3. Combat Vehicle Command and Control (93) Technical Report (Draft Final). Evaluation of the Combat Vehicle Command and Control System. Operational Effectiveness of an Armor Battalion

    DTIC Science & Technology

    1993-12-15

    6 12.8 14 29.2 Services Staff School (CAS 3) Armor Officer Advance 22 46.8 27 56.3 Course ( AOAC ) Armor Officer Basic 46 97.9 48 100 Course (AOBC) NCO...Control (CVCC) Program, 22 March 1989. The CVCC research program investigates advanced digital and thermal technologies to enhance mounted forces’ command...113 22 . Mean Performance Data for Collect Threat Information Hypothesis, by Stage andCondition ................................... 115 23

  4. A Numerical Model of Armor Development in Flash Flood-Dominated Channels: Sensitivity to Sediment Supply, Hydrograph Shape, and Base Flow

    NASA Astrophysics Data System (ADS)

    Goodwin, K.; Johnson, J. P.; Viparelli, E.

    2015-12-01

    Most gravel-transporting rivers with perennial base flow are armored, with bed surface grain size distributions that are coarser than the subsurface. In contrast, ephemerally flowing rivers, which are commonly flash flood-dominated, are typically unarmored. Both high sediment supply and elevated shear stresses have been identified as processes that may prevent armor development. We use a one-dimensional morphodynamic model that conserves mass and momentum, and tracks grain size distributions of bedload, surface, and subsurface to explore the parameter space of the armor ratio (Surface D50 / Subsurface D50) varying sediment supply, flood peak magnitude, flood duration, and base flow magnitude, including ephemeral hydrographs with no base flow. Our base case in terms of sediment supply, grain size distribution, and hydrograph is based on the Nahal Yatir, an ephemerally flowing river in the Negev Desert. Sensitivity analysis was conducted to quantitatively rank the importance of each input parameter. We found that armor ratio was the most sensitive to changes in base flow magnitude. In perennially flowing rivers, base flows can preferentially transport smaller grain sizes. In ephemerally flowing rivers, the modeling suggests that a large percentage of flow occurs above the threshold of motion for all grain sizes, transporting all grain sizes nearly equally, resulting in minimal armor development. We find that sediment supply rate and hydrograph shape have measurable but smaller influences on armoring.

  5. Primers ITS1, ITS2 and ITS4 detect the intraspecies variability in the internal transcribed spacers and 5.8S rRNA gene region in clinical isolates of fungi.

    PubMed

    Korabecná, M; Liska, V; Fajfrlík, K

    2003-01-01

    Restriction fragment length polymorphism analysis of the 5.8S rRNA gene and the internal transcribed spacers (ITS1 and ITS2) was used for examination of 66 isolates belonging to 19 species. Intraspecies variability was found in the examined region of 11 species (Candida albicans, C. catenulata, C. colliculosa, C. glabrata, C. kefyr, C. melinii, C. parapsilosis, C. guillermondii, C. solanii, C. tropicalis, Saccharomyces cerevisiae). Region of ITS-5.8S rDNA was amplified using the primers ITS1 and ITS4. The amplicons were digested by HaeIII, HinfI and CfoI. The recognized intraspecies variability was confirmed in the second step, in which the shorter fragments of this region were amplified using primers ITS1 and ITS2 and analyzed by capillary electrophoresis. Considerable intraspecific variability renders this method unsuitable for species identification, whereas it can be useful for epidemiological tracing of isolates.

  6. Use of PCR primers and probes based on the 23S rRNA and internal transcription spacer (ITS) gene sequence for the detection and enumerization of Lactobacillus acidophilus and Lactobacillus plantarum in feed supplements.

    PubMed

    Tsai, Cheng-Chih; Lai, Chieh-Hsien; Yu, Bi; Tsen, Hau-Yang

    2010-06-01

    Novel polymerase chain reaction (PCR) primers designed from the 16S-23S internal transcription spacer (ITS) rRNA and 23S rRNA genes, respectively, were used for the specific detection of Lactobacillus acidophilus and Lactobacillus plantarum. Molecular weights of the PCR products were 221 and 599 bp, respectively. Strains of L. acidophilus and L. plantarum obtained from the culture center, dairy products, infant stool and other samples, could be identified with these PCR primers. DNAs from other lactic acid bacteria (LAB) species including strains of Lactobacillus pentosus which was closely related to L. plantarum, and bacteria species other than LAB, would not generate the false positive results. When this PCR primer set was used for the detection of L. acidophilus and L. plantarum in feed supplement or feed starter samples, reliable results were obtained. Furthermore, when these L. acidophilus or L. plantarum specific primers were used as DNA probes for the colony hybridization of L. acidophilus and L. plantarum, the viable cells of these LAB species in culture and feed supplements or starter products could be identified and enumerized. The method described here thus offers a rapid and economic way to inspect and assure the quality of the feed supplements or fermentation starters.

  7. RNA. Introduction.

    PubMed

    Bao, Marie Z; Kruger, Robert P; Rivas, Fabiola; Smith, Orla; Szewczak, Lara

    2009-02-20

    Two scientists walk into a bar. After a pint and an exchange of pleasantries, one says to the other, "Where do you come from? Scientifically, I mean." The queried scientist responds, "Out of the RNA world." "Don't we all," the asker responds chuckling. Fifteen years ago, the joke would have been made with a nod to the notion that life arose from an RNA-based precursor, the so-called "RNA world." Yet had this conversation happened last week, the scientists would also be grinning in appreciation of the extent to which contemporary cellular biology is steeped in all things RNA. Ours is truly an RNA world.In this year's special review issue, the Cell editorial team has brought together articles focused on RNA in the modern world, providing perspectives on classical and emerging areas of inquiry. We extend our thanks to the many distinguished experts who contributed their time and effort as authors and reviewers to make the issue informative, thought-provoking, and timely. We hope that this collection of articles, written as we stand on the verge of a new wave of RNA biology, edifies and inspires by revealing the inner workings of these versatile molecules and by highlighting the next key questions that need to be addressed as we strive to understand the full functional scope of RNA in cells.

  8. Intraspecific variation in Radopholus similis isolates assessed with restriction fragment length polymorphism and DNA sequencing of the internal transcribed spacer region of the ribosomal RNA cistron.

    PubMed

    Elbadri, Gamal A A; De Ley, Paul; Waeyenberge, Lieven; Vierstraete, Andy; Moens, Maurice; Vanfleteren, Jacques

    2002-02-01

    Restriction fragment length polymorphism and direct sequencing of the internal transcribed spacer rDNA region of 19 isolates of Radopholus similis yielded significant diversity, both among isolates and within some individuals. Restriction fragment length polymorphism with HaeIII, AluI and Tru9I yielded two sets of patterns. Digestion with RsaI revealed one or two supernumerary bands in single nematodes from five isolates, and sequencing confirmed microheterogeneity in four of these. Phylogenetic analysis grouped most isolates closely together, except for the five isolates with additional bands for RsaI. Our data reveal more population structure than previously found and lend further support to the synonymy of R. similis and 'Radopholus citrophilus'.

  9. Sequence differences in the internal transcribed spacer 1 and 5.8S ribosomal RNA among three Moniezia species isolated from ruminants in Japan.

    PubMed

    Ohtori, Maiko; Aoki, Mikiko; Itagaki, Tadashi

    2015-01-01

    This study was designed to clarify the differences in the internal transcribed spacer (ITS) 1 and 5.8S nucleotide sequences of Moniezia expansa, M. benedeni and M. monardi isolated from ruminants in Japan and to determine their phylogenetic relationships. A 98% similarity in the 5.8S sequences was observed among the 3 Moniezia species, whereas many nucleotide indels and substitutions were observed in the ITS1 sequences among the three Moniezia species. These results suggest that the ITS1 region could serve as a potential marker for discriminating the 3 Moniezia species. In the phylogenetic tree based on the ITS1 sequences, M. monardi and M. benedeni showed genetically closer relationship to each other than to M. expansa.

  10. Controls on and effects of armoring and vertical sorting in aeolian dune fields: A numerical simulation study

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Narteau, Clément; Rozier, Olivier

    2016-03-01

    Unlike ripples, there are only few numerical studies on grain size segregation at the scale of dunes in aeolian environments. Here we use a cellular automaton model to analyze vertical sorting in granular mixtures under steady unidirectional flow conditions. We investigate the feedbacks between dune growth and the segregation mechanisms by varying the size of coarse grains and their proportion within the bed. We systematically observe the development of a horizontal layer of coarse grains at the top of which sorted bed forms may grow by amalgamation. The formation of such an armor layer controls the overall sediment transport and availability. The emergence of dunes and the transition from barchan to transverse dune fields depend only on the grain size distribution of the initial sediment layer. As confirmed by observation, this result indicates that armor layers should be present in most arid deserts, where they are likely to control dune morphodynamics.

  11. Process evaluation and characterization of TiC coating on graphite for doublet III limiters and neutral beam armor

    NASA Astrophysics Data System (ADS)

    Trester, P. W.; Sevier, D. L.; Chin, J.; Horner, M. H.; Staley, H. G.; Kaplan, R.

    An investigation was conducted to evaluate a thin coating of TiC deposited on a graphite substrate by a commercial CVD coating process. Microstructural analyses are presented for specimens positioned at various locations within the retort during the CVD coating runs. Coating requirements for thickness, quality and uniformity were met. These findings provide the data base for production coating graphite neutral-beam armor and limiter tiles for Tokamaks.

  12. Development of a Meso-Scale Material Model for Ballistic Fabric and Its Use in Flexible-Armor Protection Systems

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Bell, W. C.; Arakere, G.; He, T.; Xie, X.; Cheeseman, B. A.

    2010-02-01

    A meso-scale ballistic material model for a prototypical plain-woven single-ply flexible armor is developed and implemented in a material user subroutine for the use in commercial explicit finite element programs. The main intent of the model is to attain computational efficiency when calculating the mechanical response of the multi-ply fabric-based flexible-armor material during its impact with various projectiles without significantly sacrificing the key physical aspects of the fabric microstructure, architecture, and behavior. To validate the new model, a comparative finite element method analysis is carried out in which: (a) the plain-woven single-ply fabric is modeled using conventional shell elements and weaving is done in an explicit manner by snaking the yarns through the fabric and (b) the fabric is treated as a planar continuum surface composed of conventional shell elements to which the new meso-scale unit-cell based material model is assigned. The results obtained show that the material model provides a reasonably good description for the fabric deformation and fracture behavior under different combinations of fixed and free boundary conditions. Finally, the model is used in an investigation of the ability of a multi-ply soft-body armor vest to protect the wearer from impact by a 9-mm round nose projectile. The effects of inter-ply friction, projectile/yarn friction, and the far-field boundary conditions are revealed and the results explained using simple wave mechanics principles, high-deformation rate material behavior, and the role of various energy-absorbing mechanisms in the fabric-based armor systems.

  13. Effects of Surface Treatment and Interfacial Strength on the Damage Propagation in Layered Transparent Armor under Impact

    DTIC Science & Technology

    2011-03-20

    made of 6061-T6 aluminum alloy with a common diameter of 31.75 mm. An image of this test- ing configuration is shown in Fig. 8. In addition to the...TERMS Impact Response, Transparent Armor, Impact Damage, Surface Effects Wayne Chen Purdue University Sponosored Program Services Purdue University West...Research Symposium Series of School of Aeronautics and Astronautics, March 23, 2010, Purdue University. (c) Presentations 1.00 Number of Presentations

  14. Thermomechanical Processing and Texture Development in Ni-Cr-Mo and Mn-Mo-B Armor Steels

    DTIC Science & Technology

    1984-04-01

    Homestead plant of Mon Valley Works (contract No. DAAG46-82-C-0029). During this past year, work has been con- ducted on the 2-inch-thick plates...of these two grades of conven- tional armor have been produced routinely at the U. S. Steel Homestead plant for many years. By the introduction of a...similar. Large, discrete Fe3C particles were formed on lath boundaries and in ferrite grains. This extensive carbide precipitation and particle growth were

  15. Army’s Management of the Operations and Support Phase of the Acquisition Process for Body Armor

    DTIC Science & Technology

    2009-12-08

    identification and return of specified ESAPI lot numbers . 4 Finding A. Interceptor Body Armor Logistics Support The Army should...027/2009. Army Message 292/2008 provides instructions for returning a series of lot numbers to PEO Soldier. Army Message 027/2009 provides similar...instructions, identifies additional ESAPI lot numbers , and states: Commanders and CIFS [Central Issuing Facilities], Depots, and any other OCIE

  16. Bone histology sheds light on the nature of the "dermal armor" of the enigmatic sauropod dinosaur Agustinia ligabuei Bonaparte, 1999

    NASA Astrophysics Data System (ADS)

    Bellardini, Flavio; Cerda, Ignacio A.

    2017-02-01

    Agustinia ligabuei is an Early Cretaceous sauropod dinosaur from the northwest of Patagonia that is currently the topic of debate with respect to its phylogenetic position and atypical dermal armor. The presence of four morphotypes of laminar and transversely elongated putative osteoderms was used to consider Agustinia as an armored sauropod. Regarding the different hypotheses about the identity of the bony structures of Agustinia (e.g., osteoderms, cervical or dorsal ribs, hypertrophied elements), a comparative histological analysis has been carried out. Histological evidence is presented herein and reveals that none of the morphotypes of Agustinia shows a primary bone tissue formed by structural fiber bundles as in other sauropod dinosaur osteoderms. Furthermore, on the basis of their gross morphology and microstructure, the bony structures originally classified as types 1 + 4 and 3 are more comparable respectively with dorsal and cervical ribs than any other kind of dermal or bony element. Due to poor preservation, the nature of the type 2 cannot be assessed but is here tentatively assigned to a pelvic girdle element. Although a phylogenetic reassessment of Agustinia is not the purpose of this paper, our paleohistological analyses have broader implications: by not supporting the dermal armor hypothesis for Agustinia, its inclusion in Lithostrotia is not justified in the absence of other diagnostic features.

  17. Bone histology sheds light on the nature of the "dermal armor" of the enigmatic sauropod dinosaur Agustinia ligabuei Bonaparte, 1999.

    PubMed

    Bellardini, Flavio; Cerda, Ignacio A

    2017-02-01

    Agustinia ligabuei is an Early Cretaceous sauropod dinosaur from the northwest of Patagonia that is currently the topic of debate with respect to its phylogenetic position and atypical dermal armor. The presence of four morphotypes of laminar and transversely elongated putative osteoderms was used to consider Agustinia as an armored sauropod. Regarding the different hypotheses about the identity of the bony structures of Agustinia (e.g., osteoderms, cervical or dorsal ribs, hypertrophied elements), a comparative histological analysis has been carried out. Histological evidence is presented herein and reveals that none of the morphotypes of Agustinia shows a primary bone tissue formed by structural fiber bundles as in other sauropod dinosaur osteoderms. Furthermore, on the basis of their gross morphology and microstructure, the bony structures originally classified as types 1 + 4 and 3 are more comparable respectively with dorsal and cervical ribs than any other kind of dermal or bony element. Due to poor preservation, the nature of the type 2 cannot be assessed but is here tentatively assigned to a pelvic girdle element. Although a phylogenetic reassessment of Agustinia is not the purpose of this paper, our paleohistological analyses have broader implications: by not supporting the dermal armor hypothesis for Agustinia, its inclusion in Lithostrotia is not justified in the absence of other diagnostic features.

  18. A recurrent regulatory change underlying altered expression and Wnt response of the stickleback armor plates gene EDA

    PubMed Central

    O'Brown, Natasha M; Summers, Brian R; Jones, Felicity C; Brady, Shannon D; Kingsley, David M

    2015-01-01

    Armor plate changes in sticklebacks are a classic example of repeated adaptive evolution. Previous studies identified ectodysplasin (EDA) gene as the major locus controlling recurrent plate loss in freshwater fish, though the causative DNA alterations were not known. Here we show that freshwater EDA alleles have cis-acting regulatory changes that reduce expression in developing plates and spines. An identical T → G base pair change is found in EDA enhancers of divergent low-plated fish. Recreation of the T → G change in a marine enhancer strongly reduces expression in posterior armor plates. Bead implantation and cell culture experiments show that Wnt signaling strongly activates the marine EDA enhancer, and the freshwater T → G change reduces Wnt responsiveness. Thus parallel evolution of low-plated sticklebacks has occurred through a shared DNA regulatory change, which reduces the sensitivity of an EDA enhancer to Wnt signaling, and alters expression in developing armor plates while preserving expression in other tissues. DOI: http://dx.doi.org/10.7554/eLife.05290.001 PMID:25629660

  19. Puget Sound Shorelines and the Impacts of Armoring-Proceedings of a State of the Science Workshop, May 2009

    USGS Publications Warehouse

    : Shipman, Hugh; Dethier, Megan N.; Gelfenbaum, Guy; Fresh, Kurt L.; Dinicola, Richard S.

    2010-01-01

    The widespread extent and continued construction of seawalls and bulkheads on Puget Sound's beaches has emerged as a significant issue in shoreline management and coastal restoration in the region. Concerns about the impacts of shoreline armoring and managing the potential risks to coastal property are in many ways similar to those in other places, but Puget Sound also poses unique challenges related to its sheltered setting, glacially formed geology, rich estuarine ecology, and historical development pattern. The effects of armoring on shorelines are complex, involving both physical and biological science and requiring consideration of the cumulative impacts of small-scale activities over large scales of space and time. In addition, the issue is controversial, as it often places strongly held private interests in protecting shoreline property against broad public mandates to preserve shorelines for public uses and to protect environmental resources. Communities making difficult decisions about regulating shoreline activities and prioritizing restoration projects need to be informed by the best science available. To address these issues, a scientific workshop was convened in May 2009, specifically to bring local and national experts together to review the state of the science regarding the physical and biological impacts of armoring on sheltered shorelines such as those of Puget Sound.

  20. Comparing the comfort and potential military performance restriction of neck collars from the body armor of six different countries.

    PubMed

    Breeze, John; Watson, Celia H; Horsfall, Ian; Clasper, Jon

    2011-11-01

    The aim of this trial was to undertake an assessment of ballistic neck collars to assess comfort and potential military performance restriction. Neck collars from six different countries were procured with 71 U.K. servicemen assessing two randomly allocated collars to rate one against the other. 58% of participants had worn UK neck collars previously on exercise, but only 6% had used them on operational tours. Body armor with shorter and thinner collars was rated the most comfortable, despite lying close to the neck. It was easier to aim a rifle wearing collars with overlapping segments, especially when in the prone position. Although higher and more rigid collars fared worse overall, this could potentially be offset by the higher levels of ballistic protection they provide. There is a need to evaluate other methods of protecting the neck such as nape protectors and ballistic scarves in combination with the use of backpacks and biometric data collection. Currently, there exists no agreed method of performing ergonomic (or human factor) assessments of the varying components of military body armor systems. Published standards for the minimum military performance requirements of the various components of body armor, including neck collars, need to be established.

  1. Splicing of two internal and four carboxyl-terminal alternative exons in nonmuscle tropomyosin 5 pre-mRNA is independently regulated during development.

    PubMed

    Dufour, C; Weinberger, R P; Schevzov, G; Jeffrey, P L; Gunning, P

    1998-07-17

    Four nonmuscle tropomyosin isoforms have been reported to be produced from the rat Tm5 gene by alternative splicing (Beisel, K. W., and Kennedy, J. E. (1994) Gene (Amst.) 145, 251-256). In order to detect additional isoforms that might be expressed from that gene, we used reverse transcriptase-polymerase chain reaction assays and evaluated the presence of all product combinations of two alternative internal exons (6a and 6b) and four carboxyl-terminal exons (9a, 9b, 9c, and 9d) in developing and adult rat brain. We identified five different combinations for exon 9 (9a + 9b, 9a + 9c, 9a + 9d, 9c, and 9d), and the exon combinations 9a + 9c and 9a + 9d were previously unreported. Each of these combinations existed with both exon 6a and exon 6b. Thus, the rat brain generates at least 10 different isoforms from the Tm5 gene. Northern blot hybridization with alternative exon-specific probes revealed that these isoforms were also expressed in a number of different adult rat tissues, although some exons are preferentially expressed in particular tissues. Studies of regulation of the 10 different Tm5 isoform mRNAs during rat brain development indicated that no two isoforms are coordinately accumulated. Furthermore, there is a developmental switch in the use of exon 6a to exon 6b from embryonic to adult isoforms. TM5 protein isoforms show a differential localization in the adult cerebellum.

  2. Differential Regulation of rRNA and tRNA Transcription from the rRNA-tRNA Composite Operon in Escherichia coli

    PubMed Central

    Takada, Hiraku; Shimada, Tomohiro; Dey, Debashish; Quyyum, M. Zuhaib; Nakano, Masahiro; Ishiguro, Akira; Yoshida, Hideji; Yamamoto, Kaneyoshi; Sen, Ranjan

    2016-01-01

    Escherichia coli contains seven rRNA operons, each consisting of the genes for three rRNAs (16S, 23S and 5S rRNA in this order) and one or two tRNA genes in the spacer between 16S and 23S rRNA genes and one or two tRNA genes in the 3’ proximal region. All of these rRNA and tRNA genes are transcribed from two promoters, P1 and P2, into single large precursors that are afterward processed to individual rRNAs and tRNAs by a set of RNases. In the course of Genomic SELEX screening of promoters recognized by RNA polymerase (RNAP) holoenzyme containing RpoD sigma, a strong binding site was identified within 16S rRNA gene in each of all seven rRNA operons. The binding in vitro of RNAP RpoD holoenzyme to an internal promoter, referred to the promoter of riRNA (an internal RNA of the rRNA operon), within each 16S rRNA gene was confirmed by gel shift assay and AFM observation. Using this riRNA promoter within the rrnD operon as a representative, transcription in vitro was detected with use of the purified RpoD holoenzyme, confirming the presence of a constitutive promoter in this region. LacZ reporter assay indicated that this riRNA promoter is functional in vivo. The location of riRNA promoter in vivo as identified using a set of reporter plasmids agrees well with that identified in vitro. Based on transcription profile in vitro and Northern blot analysis in vivo, the majority of transcript initiated from this riRNA promoter was estimated to terminate near the beginning of 23S rRNA gene, indicating that riRNA leads to produce the spacer-coded tRNA. Under starved conditions, transcription of the rRNA operon is markedly repressed to reduce the intracellular level of ribosomes, but the levels of both riRNA and its processed tRNAGlu stayed unaffected, implying that riRNA plays a role in the continued steady-state synthesis of tRNAs from the spacers of rRNA operons. We then propose that the tRNA genes organized within the spacers of rRNA-tRNA composite operons are expressed

  3. Propagation of sediment pulses in flume experiments simulating gravel augmentation in armored channels downstream of dams

    NASA Astrophysics Data System (ADS)

    Fadde, J.; Venditti, J. G.; Sklar, L. S.; Wydzga, A.; Nelson, P. A.; Dietrich, W. E.

    2005-12-01

    Gravel augmentation is an increasingly common river restoration strategy for armored channels downstream of dams, however, few analytical tools are available to assist river managers in selecting the appropriate sediment volumes, grain sizes, and frequency of additions to achieve desired geomorphic and ecological outcomes. Coarse sediment additions are often intended to improve habitat for spawning salmonids by altering stream bed grain size distributions, and increasing the frequency of bed mobilization and the diversity of channel morphology. Here we report preliminary results of an ongoing laboratory investigation in which we simulate the gravel augmentation process and document the spatial and temporal evolution of the bed in response to pulses of elevated fine gravel supply. The experiments are conducted in a 30-m long, 0.86-m wide flume, with a calibrated sediment feed and a tipping bucket type sediment trap that provides a continuous record of sediment flux at the downstream end of the flume. We created an initial armored bed by first achieving an active transport equilibrium slope and then shutting off the sediment feed and allowing the bed to coarsen and degrade until the transport rate became negligible. We then introduced gravel pulses of various volumes and grain sizes, and mapped the propagation of the wave of added sediment as it moved through the flume. The sediments comprising each pulse are painted distinct colors to aid in mapping and to quantify the extent of exchange with the armored bed. Mapping techniques include planform maps of zones of active transport and temporal contours of width-averaged concentrations of added gravel. We also documented the changes in bed grain size distribution using manual pebble counts before and after each run and analysis of high resolution photographs of the bed taken during the run. We also collected frequent bedload samples at regular locations along the flume length to document the movement of the gravel pulse

  4. Internal Transcribed Spacer 2 (nu ITS2 rRNA) Sequence-Structure Phylogenetics: Towards an Automated Reconstruction of the Green Algal Tree of Life

    PubMed Central

    Buchheim, Mark A.; Keller, Alexander; Koetschan, Christian; Förster, Frank; Merget, Benjamin; Wolf, Matthias

    2011-01-01

    Background Chloroplast-encoded genes (matK and rbcL) have been formally proposed for use in DNA barcoding efforts targeting embryophytes. Extending such a protocol to chlorophytan green algae, though, is fraught with problems including non homology (matK) and heterogeneity that prevents the creation of a universal PCR toolkit (rbcL). Some have advocated the use of the nuclear-encoded, internal transcribed spacer two (ITS2) as an alternative to the traditional chloroplast markers. However, the ITS2 is broadly perceived to be insufficiently conserved or to be confounded by introgression or biparental inheritance patterns, precluding its broad use in phylogenetic reconstruction or as a DNA barcode. A growing body of evidence has shown that simultaneous analysis of nucleotide data with secondary structure information can overcome at least some of the limitations of ITS2. The goal of this investigation was to assess the feasibility of an automated, sequence-structure approach for analysis of IT2 data from a large sampling of phylum Chlorophyta. Methodology/Principal Findings Sequences and secondary structures from 591 chlorophycean, 741 trebouxiophycean and 938 ulvophycean algae, all obtained from the ITS2 Database, were aligned using a sequence structure-specific scoring matrix. Phylogenetic relationships were reconstructed by Profile Neighbor-Joining coupled with a sequence structure-specific, general time reversible substitution model. Results from analyses of the ITS2 data were robust at multiple nodes and showed considerable congruence with results from published phylogenetic analyses. Conclusions/Significance Our observations on the power of automated, sequence-structure analyses of ITS2 to reconstruct phylum-level phylogenies of the green algae validate this approach to assessing diversity for large sets of chlorophytan taxa. Moreover, our results indicate that objections to the use of ITS2 for DNA barcoding should be weighed against the utility of an automated

  5. Radiator Heat Pipes with Carbon-Carbon Fins and Armor for Space Nuclear Reactor Power Systems

    NASA Astrophysics Data System (ADS)

    Tournier, Jean-Michel; El-Genk, Mohamed

    2005-02-01

    Technologies for Space Reactor Power Systems are being developed to enable future NASA's missions early next decade to explore the farthest planets in the solar system. The choices of the energy conversion technology for these power systems require radiator temperatures that span a wide range, from 350 K to 800 K. Heat pipes with carbon-carbon fins and armor are the preferred choice for these radiators because of inherent redundancy and efficient spreading and rejection of waste heat into space at a relatively small mass penalty. The performance results and specific masses of radiator heat pipes with cesium, rubidium, and potassium working fluids are presented and compared in this paper. The heat pipes operate at 40% of the prevailing operation limit (a design margin of 60%), typically the sonic and/or capillary limit. The thickness of the carbon-carbon fins is 0.5 mm but the width is varied, and the evaporator and condenser sections are 0.15 and 1.35 m long, respectively. The 400-mesh wick and the heat pipe thin metal wall are titanium, and the carbon-carbon armor (~ 2 mm-thick) provides both structural strength and protection against meteoroids impacts. The cross-section area of the D-shaped radiator heat pipes is optimized for minimum mass. Because of the low vapor pressure of potassium and its very high Figure-Of-Merit (FOM), radiator potassium heat pipes are the best performers at temperatures above 800 K, where the sonic limit is no longer an issue. On the other hand, rubidium heat pipes are limited by the sonic limit below 762 K and by the capillary limit at higher temperature. The transition temperature between these two limits for the cesium heat pipes occurs at a lower temperature of 724 K, since cesium has lower FOM than rubidium. The present results show that with a design margin of 60%, the cesium heat pipes radiator is best at 680-720 K, the rubidium heat pipes radiator is best at 720-800 K, while the potassium heat pipes radiator is the best

  6. Radiator Heat Pipes with Carbon-Carbon Fins and Armor for Space Nuclear Reactor Power Systems

    SciTech Connect

    Tournier, Jean-Michel; El-Genk, Mohamed

    2005-02-06

    Technologies for Space Reactor Power Systems are being developed to enable future NASA's missions early next decade to explore the farthest planets in the solar system. The choices of the energy conversion technology for these power systems require radiator temperatures that span a wide range, from 350 K to 800 K. Heat pipes with carbon-carbon fins and armor are the preferred choice for these radiators because of inherent redundancy and efficient spreading and rejection of waste heat into space at a relatively small mass penalty. The performance results and specific masses of radiator heat pipes with cesium, rubidium, and potassium working fluids are presented and compared in this paper. The heat pipes operate at 40% of the prevailing operation limit (a design margin of 60%), typically the sonic and/or capillary limit. The thickness of the carbon-carbon fins is 0.5 mm but the width is varied, and the evaporator and condenser sections are 0.15 and 1.35 m long, respectively. The 400-mesh wick and the heat pipe thin metal wall are titanium, and the carbon-carbon armor ({approx} 2 mm-thick) provides both structural strength and protection against meteoroids impacts. The cross-section area of the D-shaped radiator heat pipes is optimized for minimum mass. Because of the low vapor pressure of potassium and its very high Figure-Of-Merit (FOM), radiator potassium heat pipes are the best performers at temperatures above 800 K, where the sonic limit is no longer an issue. On the other hand, rubidium heat pipes are limited by the sonic limit below 762 K and by the capillary limit at higher temperature. The transition temperature between these two limits for the cesium heat pipes occurs at a lower temperature of 724 K, since cesium has lower FOM than rubidium. The present results show that with a design margin of 60%, the cesium heat pipes radiator is best at 680-720 K, the rubidium heat pipes radiator is best at 720-800 K, while the potassium heat pipes radiator is the best

  7. RNA Research

    NASA Technical Reports Server (NTRS)

    1998-01-01

    It is generally believed that an RNA World existed at an early stage in the history of life. During this early period, RNA molecules are seen to be potentially involved in both catalysis and the storage of genetic information. It is widely believed that this RNA World was extensive and therefore a sophisticated nucleic acid replication machinery would presumably predate the translation machinery which would not be needed until later stages in the development of life. This view of an extended RNA World is not necessarily correct. From the point of view of exobiology, the difference in these two views mainly affects the significance of studies of the extent of catalysis possible by RNA- In either case, the origin of the translation machinery and the principles of RNA evolution remain central problems in exobiology. Translation presents several interrelated themes of inquiry for exobiology. First, it is essential, for understanding the very origin of life, how peptides and eventually proteins might have come to be made on the early Earth in a template directed manner. Second, it is necessary to understand how a machinery of similar complexity to that found in the ribosomes of modem organisms came to exist by the time of the last common ancestor (as detected by 16S RRNA sequence studies). Third, the RNAs that comprise the ribosome are themselves likely of very early origin and studies of their history may be very informative about the nature of the RNA World. Moreover, studies of these RNAs will contribute to a better understanding of the potential roles of RNA in early evolution.

  8. Influences on Bed Sorting and Armoring in an Upland Gravel-Cobble Bed River, Middle Fork John Day River, Oregon

    NASA Astrophysics Data System (ADS)

    McDowell, P. F.

    2014-12-01

    The Middle Fork is an unconfined to partly confined upland river with channel length of 34 km, drainage area of 250-850 km2, and channel gradients of 0.004 to 0.006 in the study area. Geology is dominated by Tertiary volcanic and volcaniclastic rocks that yield abundant coarse clasts. Surface and subsurface bed material was sampled volumetrically at twenty-five sites. The textural types range from gravelly cobbles to sandy cobbly gravels, sand content is low (2 to 13%), mud content is very low, and sorting is poor to very poor. Generally the surface layer is an open framework gravel or cobble, while the subsurface layer is a filled or partially filled framework gravel or cobble. Despite an armored appearance, only 20% of the sites are armored using the standard armor ratio (surface D50/subsurface D50). While surface layers are not coarser than their subsurface layers in terms of the median or coarse end of the distribution, they are coarser in terms of fines (ratios based on D25, D16, % sand), suggesting that alternatives to the D50armor ratio might be useful. Multivariate analysis of size fraction data reveals four distinct groups of samples, distinguished mainly by differences in proportions of coarse to fine gravels, and in abundance of sand. While one group comprises only surface samples and another subsurface samples, two of the groups are mixed. One goal of the project is to evaluate the effects of land use history on bed material characteristics and mobility. Sediment characteristics were examined in relation to distance downstream, geology, relation to debris-flow sources, land use history, and other potential influences. There are no geologic associations or downstream trends in fining or other grain size parameters. Differences in land use history, such as former dredged-mined reaches and reaches with recent restoration projects also do not explain patterns of armoring or other sediment characteristics. High variability within each reach suggests that

  9. Armoring, stability, and transport driven by fluid flow over a granular bed

    NASA Astrophysics Data System (ADS)

    Allen, Benjamin; Kudrolli, Arshad

    2015-03-01

    We discuss experiments investigating the evolution of a granular bed by a fluid flow as a function of shear rate at the fluid-bed interface. This is a model system to investigate a variety of physical examples including wind blowing over sand, sediment transport in rivers, tidal flows interacting with beaches, flows in slurry pipelines, and sand proppants in hydraulic fracturing. In order to examine the onset and entrainment of the granular bed under steady state conditions, we have constructed a novel conical rheometer system which allows a variable amount of shear to be applied to the granular bed. The grain-fluid system is index matched so that we can visualize the grains away from the sides as well as visualize the fluid flow above and below the interface by using fluorescent tracer particles. We demonstrate that the onset of erosion arises as particles rotate out of their stable position highlighting the importance of torque balance to onset. We find significant armoring of the bed, as the bed is sheared by the fluid flow. Above onset, at least three distinct regions of bed mobility can be found. We will discuss the measured integrated granular flux as a function of shear rate and compare them with empirical laws found in the geophysical literature. Supported by NSF Grant Number CBET 1335928.

  10. Combat body armor and injuries to the head, face, and neck region: a systematic review.

    PubMed

    Tong, Darryl; Beirne, Ross

    2013-04-01

    There has been a reported increase in combat-related head, face, and neck (HFN) injuries among service personnel wearing combat body armor (CBA) that have deployed to Iraq and Afghanistan. Modern ceramic plate CBA has decreased the incidence of fatal-penetrating injuries to the torso but offers no protection to the limbs and face which remain exposed to gunshot wounds and fragments from explosive devices. The aim of this review was to systematically summarize the literature reporting on HFN injuries sustained by combat personnel wearing CBA and to highlight recommendations for increased protection to the facial region. Three major contributing factors were identified with this proportional increase in HFN injuries, namely the increased survivability of soldiers because of CBA, fragments injuries from explosive devices, and the lack of protection to the face and limbs. There appears to be no evidence to suggest that by virtue of wearing CBA the likelihood of sustaining an HFN injury increases as such, but a higher incidence of fragment injuries to the HFN region may be due to the more common use of improvised explosive devicess and other explosive devices. Further development of lightweight protection for the face is needed.

  11. Effect of armor and carrying load on body balance and leg muscle function.

    PubMed

    Park, Huiju; Branson, Donna; Kim, Seonyoung; Warren, Aric; Jacobson, Bert; Petrova, Adriana; Peksoz, Semra; Kamenidis, Panagiotis

    2014-01-01

    This study investigated the impact of weight and weight distribution of body armor and load carriage on static body balance and leg muscle function. A series of human performance tests were conducted with seven male, healthy, right-handed military students in seven garment conditions with varying weight and weight distributions. Static body balance was assessed by analyzing the trajectory of center of plantar pressure and symmetry of weight bearing in the feet. Leg muscle functions were assessed by analyzing the peak electromyography amplitude of four selected leg muscles during walking. Results of this study showed that uneven weight distribution of garment and load beyond an additional 9 kg impaired static body balance as evidenced by increased sway of center of plantar pressure and asymmetry of weight bearing in the feet. Added weight on non-dominant side of the body created greater impediment to static balance. Increased garment weight also elevated peak EMG amplitude in the rectus femoris to maintain body balance and in the medial gastrocnemius to increase propulsive force. Negative impacts on balance and leg muscle function with increased carrying loads, particularly with an uneven weight distribution, should be stressed to soldiers, designers, and sports enthusiasts.

  12. Twelve years of contemporary armor evolution in a threespine stickleback population.

    PubMed

    Bell, Michael A; Aguirre, Windsor E; Buck, Nathaniel J

    2004-04-01

    Loberg Lake, Alaska was colonized by sea-run Gasterosteus aculeatus between 1983 and 1988, after the original stickleback population was exterminated. Annual samples from 1990 to 2001 reveal substantial evolution of lateral plate (armor) phenotypes. The 1990 sample was nearly monomorphic for the complete plate morph, which is monomorphic in local sea-run populations; the low plate morph, which is usually monomorphic in local freshwater populations, was absent. By 2001, the frequency of completes had declined to 11%, and lows had increased to 75%. The partial plate morph and two unusual intermediate plate phenotypes were generally rare, but occurrence of the intermediates was unexpected. These intermediate phenotypes rarely occur in other, presumably older, polymorphic populations. When low morphs first appeared, they averaged 6.8 plates per side, indicating that the ancestral plate number of low morphs is high, and their mean has subsequently declined. Contemporary evolution in this population indicates that threespine stickleback adapt to freshwater habitats within decades after invasion from the ocean, and thus phenotypes in most populations are adapted to current conditions.

  13. Recent High Heat Flux Tests on W-Rod-Armored Mockups

    SciTech Connect

    NYGREN,RICHARD E.; YOUCHISON,DENNIS L.; MCDONALD,JIMMIE M.; LUTZ,THOMAS J.; MISZKIEL,MARK E.

    2000-07-18

    In the authors initial high heat flux tests on small mockups armored with W rods, done in the small electron beam facility (EBTS) at Sandia National Laboratories, the mockups exhibited excellent thermal performance. However, to reach high heat fluxes, they reduced the heated area to only a portion ({approximately}25%) of the sample. They have now begun tests in their larger electron beam facility, EB 1200, where the available power (1.2 MW) is more than enough to heat the entire surface area of the small mockups. The initial results indicate that, at a given power, the surface temperatures of rods in the EB 1200 tests is somewhat higher than was observed in the EBTS tests. Also, it appears that one mockup (PW-10) has higher surface temperatures than other mockups with similar height (10mm) W rods, and that the previously reported values of absorbed heat flux on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed heat fluxes of {approximately}22MW/m{sup 2} were reached but the corresponding surface temperatures were somewhat higher than in EBTS. A further conclusion is that the simple 1-D model initially used in evaluating some of the results from the EBTS testing was not adequate, and 3-D thermal modeling will be needed to interpret the results.

  14. Design of the PDX Tokamak wall armor and inner limiter system

    SciTech Connect

    Kugel, H.W.; Ulrickson, M.

    1981-08-01

    The inner wall protective plates for the PDX Tokamak are designed to absorb 8 MW of neutral deuterium beam power at maximum power densities of 3 kW/cm/sup 2/ for pulse lengths of 0.5 sec. Preliminary studies indicate that the design could survive several pulses of 1 sec duration. The design consists of a tile and mounting plate structure. The mounting plates are water cooled to allow short duty cycles and beam calorimetry. The temperature and flow of the coolant is measured to obtain the injected power. A thermocouple array on the tiles provides beam position and power density profiles. Several material combinations for the tiles were subjected to thermal tests using both electron and neutral beams, and titanium carbide coated graphite was selected as the tile material. The heat transfer coefficient of the tile backing plate structure was measured to determine the maximum pulse rate allowable. The design of the armor system allows the structure to be used as a neutral beam power diagnostic and as an inner plasma limiter. The electrical and cooling systems external to the vacuum vessel are discussed.

  15. Environmental assessment of depleted uranium used in military armor-piercing rounds in terrestrial systems.

    PubMed

    Stanley, Jacob K; Coleman, Jessica G; Brasfield, Sandra M; Bednar, Anthony J; Ang, Choo Y

    2014-06-01

    Depleted uranium (DU) from the military testing and use of armor-piercing kinetic energy penetrators has been shown to accumulate in soils; however, little is known about the toxicity of DU geochemical species created through corrosion or weathering. The purpose of the present study was to assess the toxic effects and bioaccumulation potential of field-collected DU oxides to the model terrestrial invertebrates Eisenia fetida (earthworm) and Porcellio scaber (isopod). Earthworm studies were acute (72 h) dermal exposures or 28-d spiked soil exposures that used noncontaminated field-collected soils from the US Army's Yuma and Aberdeen Proving Grounds. Endpoints assessed in earthworm testing included bioaccumulation, growth, reproduction, behavior (soil avoidance), and cellular stress (neutral red uptake in coelomocytes). Isopod testing used spiked food, and endpoints assessed included bioaccumulation, survival, and feeding behavior. Concentration-dependent bioaccumulation of DU in earthworms was observed with a maximum bioaccumulation factor of 0.35; however, no significant reductions in survival or impacts to cellular stress were observed. Reproduction lowest-observed-effect concentrations (LOEC) of 158 mg/kg and 96 mg/kg were observed in Yuma Proving Ground and a Mississippi reference soil (Karnac Ferry), respectively. Earthworm avoidance of contaminated soils was not observed in 48-h soil avoidance studies; however, isopods were shown to avoid food spiked with 12.7% by weight DU oxides through digital tracking studies.

  16. Characterization of dermal plates from armored catfish Pterygoplichthys pardalis reveals sandwich-like nanocomposite structure.

    PubMed

    Ebenstein, Donna; Calderon, Carlos; Troncoso, Omar P; Torres, Fernando G

    2015-05-01

    Dermal plates from armored catfish are bony structures that cover their body. In this paper we characterized structural, chemical, and nanomechanical properties of the dermal plates from the Amazonian fish Pterygoplichthys pardalis. Analysis of the morphology of the plates using scanning electron microscopy (SEM) revealed that the dermal plates have a sandwich-like structure composed of an inner porous matrix surrounded by two external dense layers. This is different from the plywood-like laminated structure of elasmoid fish scales but similar to the structure of osteoderms found in the dermal armour of some reptiles and mammals. Chemical analysis performed using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results revealed similarities between the composition of P. pardalis plates and the elasmoid fish scales of Arapaima gigas. Reduced moduli of P. pardalis plates measured using nanoindentation were also consistent with reported values for A. gigas scales, but further revealed that the dermal plate is an anisotropic and heterogeneous material, similar to many other fish scales and osteoderms. It is postulated that the sandwich-like structure of the dermal plates provides a lightweight and tough protective layer.

  17. Persisting effects of armored military maneuvers on some soils of the Mojave Desert

    USGS Publications Warehouse

    Prose, D.V.

    1985-01-01

    Soil compaction and substrate modification produced during large-scale armored military maneuvers in the early 1940s were examined in 1981 at seven sites in California's eastern Mojave Desert Recording penetrometer measurements show that tracks left by a single pass of an M3 "medium" tank have average soil resistance values that are 50% greater than those of the surrounding untracked soil in the upper 20 cm At one site, measurements made along short segments of track that have been visually eliminated by erosion and deposition processes show a 73% increase in penetrometer resistance over adjacent, undisturbed soils Dirt roadways at three former base camp locations could not be penetrated below 5-10 cm because of extreme compaction Soil bulk density was not as sensitive an indicator of soil compaction as was penetrometer resistance Density values in the upper 10 cm of soil are not significantly different between tank tracks and undisturbed soils at most sites, and roadways at two base camps show an average increase in bulk density of only 12% over adjacent soils. Trench excavations across tank tracks show that physical modifications of the substrate can extend vertically beneath a track to a depth of 25 cm and outward from a track's edge to 50 cm These soil disturbances are probably major factors that encourage accelerated soil erosion throughout the manuever area and also retard or prevent the return of vegetation to pre-disturbance conditions ?? 1985 Springer-Verlag New York Inc.

  18. SIRE (sight-integrated ranging equipment): an eyesafe laser rangefinder for armored vehicle fire control systems

    NASA Astrophysics Data System (ADS)

    Keeter, Howard S.; Gudmundson, Glen A.; Woodall, Milton A., II

    1991-04-01

    The Sight Integrated Ranging Equipment (SIRE) incorporates an eyesafe laser rangefinder into the M-36 periscope used in tactical armored vehicles, such as the Commando Stingray light tank. The SIRE unit provides crucial range data simultaneously to the gunner and fire control computer. This capability greatly reduces 'time-to-fire', improves first-round hit probability, and increases the overall effectiveness of the vehicle under actual and simulated battlefield conditions. The SIRE can provide target range up to 10-km, with an accuracy of 10-meters. The key advantage of the SIRE over similar laser rangefinder systems is that it uses erbium:glass as the active lasing medium. With a nominal output wavelength of 1.54-microns, the SIRE can produce sufficient peak power to penetrate long atmospheric paths (even in the presence of obscurants), while remaining completely eyesafe under all operating conditions. The SIRE is the first eyesafe vehicle-based system to combine this level of accuracy, maximum range capability, and fire control interface. It simultaneously improves the accuracy and confidence of the operator, and eliminates the ocular hazard issues typically encountered with laser rangefinder devices.

  19. Oxidation and Volatilization from Tungsten Brush High Heat Flux Armor During High Temperature Steam Exposure

    SciTech Connect

    Smolik, Galen Richard; Pawelko, Robert James; Anderl, Robert Andrew; Petti, David Andrew

    2000-05-01

    Tungsten brush accommodates thermal stresses and high heat flux in fusion reactor components such as plasma facing surfaces or armor. However, inherently higher surface areas are introduced with the brush design. We have tested a specific design of tungsten brush in steam between 500 and 1100°C. Hydrogen generation and tungsten volatilization rates were determined to address fusion safety issues. The brush prepared from 3.2-mm diameter welding rods had a packing density of 85 percent. We found that both hydrogen generation and tungsten volatilization from brush, fixtured to represent a unit within a larger component, were less than projections based upon the total integrated surface area (TSA). Steam access and the escape of hydrogen and volatile oxide from void spaces within the brush are restricted compared to specimens with more direct diffusion pathways to the test environment. Hydrogen generation rates from restrained specimens based on normal surface area (NSA) remain about five times higher than rates based on total surface areas from specimens with direct steam access. Volatilization rates from restrained specimens based upon normal surface area (NSA) were only 50 percent higher than our historic cumulative maximum flux plot (CMFP) for tungsten. This study has shown that hydrogen generation and tungsten volatilization from brush do not scale according to predictions with previously determined rates, but in fact, with higher packing density could approach those from flat surfaces.

  20. An armored-cable-based fiber Bragg grating sensor array for perimeter fence intrusion detection

    NASA Astrophysics Data System (ADS)

    Hao, Jianzhong; Dong, Bo; Varghese, Paulose; Phua, Jiliang; Foo, Siang Fook

    2011-11-01

    In this paper, an armored-cable-based optical fiber Bragg grating (FBG) sensor array, for perimeter fence intrusion detection, is demonstrated and some of the field trial results are reported. The field trial was conducted at a critical local installation in Singapore in December 2010. The sensor array was put through a series of both simulated and live intrusion scenarios to test the stability and suitability of operation in the local environmental conditions and to determine its capabilities in detecting and reporting these intrusions accurately to the control station. Such a sensor array can provide perimeter intrusion detection with fine granularity and preset pin-pointing accuracy. The various types of intrusions included aided or unaided climbs, tampering and cutting of the fence, etc. The unique sensor packaging structure provides high sensitivity, crush resistance and protection against rodents. It is also capable of resolving nuisance events such as rain, birds sitting on the fence or seismic vibrations. These sensors are extremely sensitive with a response time of a few seconds. They can be customized for a desired spatial resolution and pre-determined sensitivity. Furthermore, it is easy to cascade a series of such sensors to monitor and detect intrusion events over a long stretch of fence line. Such sensors can be applied to real-time intrusion detection for perimeter security, pipeline security and communications link security.

  1. An armored-cable-based fiber Bragg grating sensor array for perimeter fence intrusion detection

    NASA Astrophysics Data System (ADS)

    Hao, Jianzhong; Dong, Bo; Varghese, Paulose; Phua, Jiliang; Foo, Siang Fook

    2012-01-01

    In this paper, an armored-cable-based optical fiber Bragg grating (FBG) sensor array, for perimeter fence intrusion detection, is demonstrated and some of the field trial results are reported. The field trial was conducted at a critical local installation in Singapore in December 2010. The sensor array was put through a series of both simulated and live intrusion scenarios to test the stability and suitability of operation in the local environmental conditions and to determine its capabilities in detecting and reporting these intrusions accurately to the control station. Such a sensor array can provide perimeter intrusion detection with fine granularity and preset pin-pointing accuracy. The various types of intrusions included aided or unaided climbs, tampering and cutting of the fence, etc. The unique sensor packaging structure provides high sensitivity, crush resistance and protection against rodents. It is also capable of resolving nuisance events such as rain, birds sitting on the fence or seismic vibrations. These sensors are extremely sensitive with a response time of a few seconds. They can be customized for a desired spatial resolution and pre-determined sensitivity. Furthermore, it is easy to cascade a series of such sensors to monitor and detect intrusion events over a long stretch of fence line. Such sensors can be applied to real-time intrusion detection for perimeter security, pipeline security and communications link security.

  2. Challenges of Engineering Grain Boundaries in Boron-Based Armor Ceramics

    NASA Astrophysics Data System (ADS)

    Coleman, Shawn P.; Hernandez-Rivera, Efrain; Behler, Kristopher D.; Synowczynski-Dunn, Jennifer; Tschopp, Mark A.

    2016-06-01

    Boron-based ceramics are appealing for lightweight applications in both vehicle and personnel protection, stemming from their combination of high hardness, high elastic modulus, and low density as compared to other ceramics and metal alloys. However, the performance of these ceramics and ceramic composites is lacking because of their inherent low fracture toughness and reduced strength under high-velocity threats. The objective of the present article is to briefly discuss both the challenges and the state of the art in experimental and computational approaches for engineering grain boundaries in boron-based armor ceramics, focusing mainly on boron carbide (B4C) and boron suboxide (B6O). The experimental challenges involve processing these ceramics at full density while trying to promote microstructure features such as intergranular films to improve toughness during shock. Many of the computational challenges for boron-based ceramics stem from their complex crystal structure which has hitherto complicated the exploration of grain boundaries and interfaces. However, bridging the gaps between experimental and computational studies at multiple scales to engineer grain boundaries in these boron-based ceramics may hold the key to maturing these material systems for lightweight defense applications.

  3. The L1Tc non-LTR retrotransposon of Trypanosoma cruzi contains an internal RNA-pol II-dependent promoter that strongly activates gene transcription and generates unspliced transcripts.

    PubMed

    Heras, Sara R; López, Manuel C; Olivares, Mónica; Thomas, M Carmen

    2007-01-01

    L1Tc is the best represented autonomous LINE of the Trypanosoma cruzi genome, throughout which several functional copies may exist. In this study, we show that the first 77 bp of L1Tc (Pr77) (also present in the T. cruzi non-autonomous retrotransposon NARTc, in the Trypanosoma brucei RIME/ingi elements, and in the T. cruzi, T. brucei and Leishmania major degenerate L1Tc/ingi-related elements [DIREs]) behave as a promoter element that activates gene transcription. The transcription rate promoted by Pr77 is 10-14-fold higher than that mediated by sequences located upstream from the T. cruzi tandemly repeated genes KMP11 and the GAPDH. The Pr77 promoter-derived mRNAs initiate at nucleotide +1 of L1Tc, are unspliced and translated. L1Tc transcripts show a moderate half life and are RNA pol II dependent. The presence of an internal promoter at the 5' end of L1Tc favors the production of full-length L1Tc RNAs and reinforces the hypothesis that this mobile element may be naturally autonomous in its transposition.

  4. Optimizing a basal bark spray of dinotefuran to manage armored scales (Hemiptera: Diaspididae) in Christmas tree plantations.

    PubMed

    Cowles, Richard S

    2010-10-01

    The armored scales Fiorinia externa Ferris and Aspidiotus cryptomeriae Kuwana (Hemiptera: Diaspididae) are increasingly damaging to Christmas tree plantings in southern New England. The systemic insecticide dinotefuran was investigated for selectively suppressing armored scale populations relative to their natural enemies in cooperating growers' fields in 2008 and 2009. Banded soil application of dinotefuran resulted in poor control. However, a dinotefuran spray applied to the basal 25 cm of trunk resulted in its absorption through the bark, translocation to the foliage, and good efficacy. The basal bark spray did not significantly impact the activity of predators Chilocorus stigma (Say) or Cybocephalus nipponicus Enrody-Younga and in 2009 showed a dosage-dependent improvement in the percentage of scales parasitized by Encarsia citrina Craw. A field dosage-response factorial experiment revealed that a 0.25% (vol:vol) addition of a surfactant with dinotefuran did not enhance insecticidal effect. Probit-transformed scale population reduction relative to the untreated check was subjected to linear regression analysis; reduction of scale populations was proportional to the log of insecticide dosage, whereas basal bark spray efficacy declined in proportion to the cube of tree height. The regression equation can be used to optimize dosage relative to tree height. Excellent efficacy resulted from basal bark spray application dates of 28 April (prebud break) to mid-June, but earlier spray timing within that treatment window had fewer crawlers discoloring new growth with their short-lived feeding. A basal bark spray of dinotefuran is well suited for integration with natural enemies to manage armored scales in Christmas tree plantations.

  5. A Preliminary Report on the Strength and Metallography of a Bimetallic Friction Stir Weld Joint Between AA6061 and MIL-DTL-46100E High Hardness Steel Armor

    DTIC Science & Technology

    2012-11-26

    plates of 6061-T6 aluminum alloy and High Hardness steel armor (MIL-STD-46100) were successfully joined by the friction stir welding ( FSW ) process using a...b 124 c FSW 194 d High Hardness Steel (HHS) base material 1034 e GMAW f tbd g AA6061/HHS FSW joint 176 8 a Kaiser Aluminum Certified Test...bimetallic friction stir weld joint between AA6061 and MIL-DTL-46100E High Hardness steel armor. ABSTRACT One half inch thick plates of 6061-T6 aluminum

  6. River bed armoring in a local scour under no-supply conditions; experimental investigation and numerical model validation

    NASA Astrophysics Data System (ADS)

    Török, Gergerly; Baranya, Sandor; Rüther, Nils

    2016-04-01

    The aim of this study is to present a novel method for numerical modeling of morphological changes. The essence of the method doesn't mean the development of a new sediment transport formula, but the combined application of the existing, conditionally validated sediment transport models. Many bedload transport formulas can be found in the literature, which were developed based on different field and laboratory measurements. Thus, the most reliability of the models usually can be expected only for the given morphological and hydrological conditions connected to the base measurements. However, commonly in the analysed cases the morphological and hydrological features are more variable both in time and in space. Therefore, the hypothesis of this study is that, complex hydromorphological processes can't be modeled by one sediment transport formula. The authors present a solution based on laboratory experiments. Spatio-temporal developments of bed armoring, local scouring and local sediment deposition under no supply condition was monitored and analysed. The sediment transport model of Wilcock and Crowe (2003) was expected to calculate properly the local scouring and bed armoring processes, while the motion and aggradation of the finer materials were supposed to estimate reliably by the van Rijn formula (1984). The main challenge of the combining method is to find an appropriate criterion to decide which transport formula is activated in the given space and in the given time step. The result of the investigation showed that the most reliable criteria is based on the d50 value. As soon as the d50 grain size goes below a certain value, van Rijn is activated, otherwise the Wilcock and Crowe formula calculates the sorting and armoring processes. The results show that the combining method clearly improve the reliability of the morphological calculation. The benefit of the Wilcock and Crowe model is that it estimates quite well the sediment transport in mixed or armored

  7. Metabolic demands of body armor on physical performance in simulated conditions.

    PubMed

    Ricciardi, Richard; Deuster, Patricia A; Talbot, Laura A

    2008-09-01

    The purpose of this study was to examine physical work performance, energy cost, and physiological fatigue in military personnel during simulated operational conditions. Using a within-subject, repeated-measures design, 34 military personnel volunteered to undergo two experimental conditions: with body armor (BA+) and without BA (BA-). Subjects walked on a treadmill for 30 minutes and completed a physical performance battery during each of two sessions, which were separated by > or = 5 days. Subjects with BA+ as compared with BA- had significantly greater increases in: oxygen uptake (VO2) at slow (16.8 +/- 1.5 vs. 18.8 +/- 1.7 mL x kg(-1) x min(-1)) and moderate paces (34.8 +/- 3.9 vs. 40.8 +/- 5.0 mL x kg(-1) x min(-1)); blood lactate at a moderate pace (4.0 +/- 2.4 vs. 6.7 +/- 2.6 mmol/L); heart rate at slow (107 +/- 14 vs. 118 +/- 16 beats per minute) and moderate paces (164 +/- 16 vs. 180 +/- 13 beats per minute); and ratings of perceived physical exertion at slow (8.4 +/- 1.5 vs. 10.4 +/- 1.8) and moderate paces (14.3 +/- 2.3 vs. 16.7 +/- 2.1). Physical tasks were significantly affected by BA: under BA+, men performed 61% fewer pull-ups and women's hang time was reduced by 63%; stair stepping was reduced by 16% for both men and women. BA significantly impacted the physical work capacity of militarily relevant tasks. Specifically, wearing BA significantly increased VO2 when walking at both slow and moderate paces. The potential for physical exhaustion is high and performance of physical tasks is markedly impaired when wearing BA.

  8. [Strategy of Aspergillus fumigatus to evade attacks from host--projectile weapons and armor].

    PubMed

    Toyotome, Takahito; Watanabe, Akira; Iwasaki, Aya; Kamei, Katsuhiko

    2009-01-01

    Humans are continually inhaling environmental fungi. When the host immune system is competent, the inhaled fungi are cleared away from the lung by host defense mechanisms. But in immunocompromised individuals, the environmental fungi (e.g., Aspergillus fumigatus) sometimes cause infection. Pathogenic fungi possess various mechanisms to invade the host. A. fumigatus is no exception in possessing several virulence factors and defense mechanisms against host immune attack.One of the virulence factors is secondary metabolite. A. fumigatus produces a variety of secondary metabolites, and the fungal products in culture supernatant have a strong apoptosis-inducing activity to macrophages and alveolar epithelial cells. These data suggest that A. fumigatus is equipped with special projectile weapons for destroying host physical barriers and immunological barriers in lung.The fungal cell wall is an easy target for the host to recognize the pathogen. One of the fungal cell wall components, beta- (1,3) -glucan, is a major fungal PAMP (pathogen-associated molecular pattern), which is recognized by one of the pattern recognition receptors, dectin-1. The interaction induces activation of transcription factors and production of proinflammatory cytokines in the host cell. However, beta-glucan of A. fumigatus is strongly exposed to the surface only during the "swollen-conidia" phase. In the hyphal phase, the fungus is covered with "armor", i.e., other cell wall components to minimize the exposure of the beta-glucan structure. These findings suggest that A. fumigatus evades the recognition and the attack from host by masking beta-glucan. A. fumigatus has clever mechanisms to defend itself and to attack the host immune system.

  9. Engineering Structurally Interacting RNA (sxRNA).

    PubMed

    Doyle, Francis; Lapsia, Sameer; Spadaro, Salvatore; Wurz, Zachary E; Bhaduri-McIntosh, Sumita; Tenenbaum, Scott A

    2017-03-28

    RNA-based three-way junctions (3WJs) are naturally occurring structures found in many functional RNA molecules including rRNA, tRNA, snRNA and ribozymes. 3WJs are typically characterized as resulting from an RNA molecule folding back on itself in cis but could also form in trans when one RNA, for instance a microRNA binds to a second structured RNA, such as a mRNA. Trans-3WJs can influence the final shape of one or both of the RNA molecules and can thus provide a means for modulating the availability of regulatory motifs including potential protein or microRNA binding sites. Regulatory 3WJs generated in trans represent a newly identified regulatory category that we call structurally interacting RNA or sxRNA for convenience. Here we show that they can be rationally designed using familiar cis-3WJ examples as a guide. We demonstrate that an sxRNA "bait" sequence can be designed to interact with a specific microRNA "trigger" sequence, creating a regulatable RNA-binding protein motif that retains its functional activity. Further, we show that when placed downstream of a coding sequence, sxRNA can be used to switch "ON" translation of that sequence in the presence of the trigger microRNA and the amount of translation corresponded with the amount of microRNA present.

  10. Engineering Structurally Interacting RNA (sxRNA)

    PubMed Central

    Doyle, Francis; Lapsia, Sameer; Spadaro, Salvatore; Wurz, Zachary E.; Bhaduri-McIntosh, Sumita; Tenenbaum, Scott A.

    2017-01-01

    RNA-based three-way junctions (3WJs) are naturally occurring structures found in many functional RNA molecules including rRNA, tRNA, snRNA and ribozymes. 3WJs are typically characterized as resulting from an RNA molecule folding back on itself in cis but could also form in trans when one RNA, for instance a microRNA binds to a second structured RNA, such as a mRNA. Trans-3WJs can influence the final shape of one or both of the RNA molecules and can thus provide a means for modulating the availability of regulatory motifs including potential protein or microRNA binding sites. Regulatory 3WJs generated in trans represent a newly identified regulatory category that we call structurally interacting RNA or sxRNA for convenience. Here we show that they can be rationally designed using familiar cis-3WJ examples as a guide. We demonstrate that an sxRNA “bait” sequence can be designed to interact with a specific microRNA “trigger” sequence, creating a regulatable RNA-binding protein motif that retains its functional activity. Further, we show that when placed downstream of a coding sequence, sxRNA can be used to switch “ON” translation of that sequence in the presence of the trigger microRNA and the amount of translation corresponded with the amount of microRNA present. PMID:28350000

  11. Studies of a laser/nuclear thermal-hardened body armor. Final report, 31 Jan 91-30 Sep 91

    SciTech Connect

    Misconi, N.Y.; Caldarella, G.J.; Roach, J.F.

    1992-08-01

    The problem of laser/nuclear hardening of body armors and other applications, such as rigid wall, etc, has been investigated in this study. Earlier results from studies of hardening against space systems, which were supported by the Air Force Office of Scientific Research (AFOSR) and carried out by the Principal Investigator during 1984 to 1989 are summarized. The concepts of particle layer and photon multiple scattering inside the layers were utilized in developing a laser shield to protect against laser weapons in the 0.22 to 2.4 micrometer region of the spectrum. Protection against the threats from C02 laser weapons are addressed, and the development of a protective shield is detailed. It is now possible to apply a coating that will protect against laser/nuclear threats and reduction of solar loads for 0.22 to 16 micrometers of the spectrum. Applications are expected for rigid walls (Army containers), human body armor, thermal jackets for military hardware, etc. Finally, a mathematical model was created to help predict how the laser hardening material will behave under specific constraints that have not yet been tested in the laboratory. Also, this model can be used to extrapolate the performance of similar materials/coatings in the mid- to far-infrared wavelengths and also predict the broadband performance.

  12. Blast response of centrally and eccentrically loaded flat-, U-, and V-shaped armored plates: comparative study

    NASA Astrophysics Data System (ADS)

    Trajkovski, J.; Kunc, R.; Prebil, I.

    2016-12-01

    Light armored vehicles (LAVs) can be exposed to blast loading by landmines or improvised explosive devices (IEDs) during their lifetime. The bottom hull of these vehicles is usually made of a few millimeters of thin armored plate that is the vehicle's weak point in a blast-loading scenario. Therefore, blast resistance and blast load redirection are very important characteristics in providing adequate vehicle as well as occupant protection. Furthermore, the eccentric nature of loading caused by landmines was found to be omitted in the studies of simplified structures like beams and plates. For this purpose, blast wave dispersion and blast response of centrally and eccentrically loaded flat-, U-, and V-shaped plates are examined using a combined finite-element-smoothed-particle hydrodynamics (FE-SPH) model. The results showed that V-shaped plates better disperse blast waves for any type of loading and, therefore, can be successfully applied in LAVs. Based on the results of the study and the geometry of a typical LAV 6× 6 , the minimum angle of V-shaped plates is also determined.

  13. 75 FR 55313 - Record of Decision (ROD) for Conversion of the 3rd Armored Cavalry Regiment (3rd ACR) to a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-10

    ... conversion, the 3rd ACR will provide the Army with a force structure that has the flexibility to respond... Infantry BCTs and Heavy Armor BCTs augmented with the protection and versatility of an additional SBCT. The... socioeconomic impacts that would be associated with the stationing of the different types of Army BCTs...

  14. Sediment mobility and bed armoring in the St Clair River: insights from hydrodynamic modeling

    USGS Publications Warehouse

    Liu, Xiaofeng; Parker, Gary; Czuba, Jonathan A.; Oberg, Kevin; Mier, Jose M.; Best, James L.; Parsons, Daniel R.; Ashmore, Peter; Krishnappan, Bommanna G.; Garcia, Marcelo H.

    2012-01-01

    The lake levels in Lake Michigan-Huron have recently fallen to near historical lows, as has the elevation difference between Lake Michigan-Huron compared to Lake Erie. This decline in lake levels has the potential to cause detrimental impacts on the lake ecosystems, together with social and economic impacts on communities in the entire Great Lakes region. Results from past work suggest that morphological changes in the St Clair River, which is the only natural outlet for Lake Michigan-Huron, could be an appreciable factor in the recent trends of lake level decline. A key research question is whether bed erosion within the river has caused an increase in water conveyance, therefore, contributed to the falling lake level. In this paper, a numerical modeling approach with field data is used to investigate the possibility of sediment movement in the St Clair River and assess the likelihood of morphological change under the current flow regime. A two-dimensional numerical model was used to study flow structure, bed shear stress, and sediment mobility/armoring over a range of flow discharges. Boundary conditions for the numerical model were provided by detailed field measurements that included high-resolution bathymetry and three-dimensional flow velocities. The results indicate that, without considering other effects, under the current range of flow conditions, the shear stresses produced by the river flow are too low to transport most of the coarse bed sediment within the reach and are too low to cause substantial bed erosion or bed scour. However, the detailed maps of the bed show mobile bedforms in the upper St Clair River that are indicative of sediment transport. Relatively high shear stresses near a constriction at the upstream end of the river and at channel bends could cause local scour and deposition. Ship-induced propeller wake erosion also is a likely cause of sediment movement in the entire reach. Other factors that may promote sediment movement, such as ice

  15. Clothing adjustments for concealed soft body armor during moderate physical exertion.

    PubMed

    Ryan, Greg A; Bishop, Stacy H; Herron, Robert L; Katica, Charles P; Elbon, Bre'anna L; Bosak, Andrew M; Bishop, Phillip

    2015-01-01

    Previous research has studied the impact of Level II concealed soft body armor (SBA) on the augmentation of heat storage in a hot environment simulating a typical summer day in the southeastern United States (wet bulb globe temperature [WBGT] = 30°C) and noted a significant difference between macro- and micro-WBGTs. The purpose of this study was to characterize the microclimate (micro-WBGT) under a concealed Level II SBA during 60 min of moderately intense work at two separate macro-WBGTs (26°C and 30°C), and to establish WBGT corrections to allow prediction of heat strain in an individual wearing a concealed Level II SBA. A single trial was performed with nine volunteers (27 ± 4 years) outfitted with a simulated standard law enforcement uniform and a traditional concealed Level II SBA, in a moderately warm environment (WBGT = 26°C). Each participant performed cycles of 12 min of walking (1.25 L · min(-1)) and 3 min of arm curls (14.3 kg, 0.6 L · min(-1)) with a 5 min rest after every other cycle, for a total of 60 minutes. This trial was compared to an identical previously completed 60-min work bout at 30°C. A two-way repeated measures ANOVA with Post hoc Bonferroni and paired samples t-test analysis was conducted. A greater difference between macro- micro-WBGTs existed at 26°C compared to the 30°C macro-WBGT. Under these conditions, a moderate work in Level II SBA requires a WBGT correction of 8.9°C and 6.2°C at macro-WBGTs of 26°C and 30°C, respectively. A modified simple linear regression prediction model was established for mean Micro-WBGT for each macro-WBGTs after the plateau point at the 30 min mark. The derivation regressions at 26°C (R(2) = 0.99), and 30°C (R(2) = 0.99) indicate that micro-WBGT could be predicted for each 15 minutes time at both macro-WBGTs tested for individuals doing moderate intensity (300 Kcals · hr(-1)) work wearing concealed Level II SBA.

  16. Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

    NASA Astrophysics Data System (ADS)

    Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

    2015-11-01

    This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced

  17. RNA families in Epstein-Barr virus.

    PubMed

    Moss, Walter N; Lee, Nara; Pimienta, Genaro; Steitz, Joan A

    2014-01-01

    Epstein-Barr virus (EBV) is a tumorigenic human γ-herpesvirus, which produces several known structured RNAs with functional importance: two are implicated in latency maintenance and tumorigenic phenotypes, EBER1 and EBER2; a viral small nucleolar RNA (v-snoRNA1) that may generate a small regulatory RNA; and an internal ribosomal entry site in the EBNA1 mRNA. A recent bioinformatics and RNA-Seq study of EBV identified two novel EBV non-coding (nc)RNAs with evolutionary conservation in lymphocryptoviruses and likely functional importance. Both RNAs are transcribed from a repetitive region of the EBV genome (the W repeats) during a highly oncogenic type of viral latency. One novel ncRNA can form a massive (586 nt) hairpin, while the other RNA is generated from a short (81 nt) intron and is found in high abundance in EBV-infected cells.

  18. RNA families in Epstein–Barr virus

    PubMed Central

    Moss, Walter N; Lee, Nara; Pimienta, Genaro; Steitz, Joan A

    2014-01-01

    Epstein–Barr virus (EBV) is a tumorigenic human γ-herpesvirus, which produces several known structured RNAs with functional importance: two are implicated in latency maintenance and tumorigenic phenotypes, EBER1 and EBER2; a viral small nucleolar RNA (v-snoRNA1) that may generate a small regulatory RNA; and an internal ribosomal entry site in the EBNA1 mRNA. A recent bioinformatics and RNA-Seq study of EBV identified two novel EBV non-coding (nc)RNAs with evolutionary conservation in lymphocryptoviruses and likely functional importance. Both RNAs are transcribed from a repetitive region of the EBV genome (the W repeats) during a highly oncogenic type of viral latency. One novel ncRNA can form a massive (586 nt) hairpin, while the other RNA is generated from a short (81 nt) intron and is found in high abundance in EBV-infected cells. PMID:24441309

  19. Armored scale insect endosymbiont diversity at the species level: genealogical patterns of Uzinura diasipipdicola in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex (Hemiptera: Coccoidea: Diaspididae).

    PubMed

    Andersen, J C; Gwiazdowski, R A; Gdanetz, K; Gruwell, M E

    2015-02-01

    Armored scale insects and their primary bacterial endosymbionts show nearly identical patterns of co-diversification when viewed at the family level, though the persistence of these patterns at the species level has not been explored in this group. Therefore we investigated genealogical patterns of co-diversification near the species level between the primary endosymbiont Uzinura diaspidicola and its hosts in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex. To do this we generated DNA sequence data from three endosymbiont loci (rspB, GroEL, and 16S) and analyzed each locus independently using statistical parsimony network analyses and as a concatenated dataset using Bayesian phylogenetic reconstructions. We found that for two endosymbiont loci, 16S and GroEL, sequences from U. diaspidicola were broadly associated with host species designations, while for rspB this pattern was less clear as C. heterophyllae (species S1) shared haplotypes with several other Chionaspis species. We then compared the topological congruence of the phylogenetic reconstructions generated from a concatenated dataset of endosymbiont loci (including all three loci, above) to that from a concatenated dataset of armored scale hosts, using published data from two nuclear loci (28S and EF1α) and one mitochondrial locus (COI-COII) from the armored scale hosts. We calculated whether the two topologies were congruent using the Shimodaira-Hasegawa test. We found no significant differences (P = 0.4892) between the topologies suggesting that, at least at this level of resolution, co-diversification of U. diaspidicola with its armored scale hosts also occurs near the species level. This is the first such study of co-speciation at the species level between U. diaspidicola and a group of armored scale insects.

  20. Collaborative Research Program on Advanced Metals and Ceramics for Armor and Anti-Armor Applications Dynamic Behavior of Non-Crystalline and Crystalline Metallic Systems

    DTIC Science & Technology

    2006-09-01

    Ramesh, K. T. A Novel Technique for Accurate Measurement of Material Properties in the Tension Kolsky Bar. International Journal of Impact Engineering...Selected Accomplishments A novel technique for producing in situ metallic glass-matrix composites (MGMCs) was developed, which was patented with both JHU...and ARL investigators as co-inventors. Using this technique , we produced a series of MGMCs with dramatically enhanced plastic strain to failure in

  1. RNA Challenges for Computational Chemists†

    PubMed Central

    Yildirim, Ilyas; Turner, Douglas H.

    2013-01-01

    Some experimental results for the thermodynamics of RNA folding cannot be explained by simple pairwise hydrogen-bonding models. Such effects include the stabilities of isoguanosine–isocytidine (iG–iC) base pairs and of various 2 × 2 nucleotide internal loops. Presumably, these results can be explained by base stacking effects, which can be partitioned into Coulombic and overlap effects. We review experimental measurements that provide benchmarks for testing the approximations and theories used for modeling nucleic acids. Quantitative agreement between experiment and theory will indicate understanding of the interactions determining RNA stability and structure. PMID:16201748

  2. RAID: a comprehensive resource for human RNA-associated (RNA-RNA/RNA-protein) interaction.

    PubMed

    Zhang, Xiaomeng; Wu, Deng; Chen, Liqun; Li, Xiang; Yang, Jinxurong; Fan, Dandan; Dong, Tingting; Liu, Mingyue; Tan, Puwen; Xu, Jintian; Yi, Ying; Wang, Yuting; Zou, Hua; Hu, Yongfei; Fan, Kaili; Kang, Juanjuan; Huang, Yan; Miao, Zhengqiang; Bi, Miaoman; Jin, Nana; Li, Kongning; Li, Xia; Xu, Jianzhen; Wang, Dong

    2014-07-01

    Transcriptomic analyses have revealed an unexpected complexity in the eukaryote transcriptome, which includes not only protein-coding transcripts but also an expanding catalog of noncoding RNAs (ncRNAs). Diverse coding and noncoding RNAs (ncRNAs) perform functions through interaction with each other in various cellular processes. In this project, we have developed RAID (http://www.rna-society.org/raid), an RNA-associated (RNA-RNA/RNA-protein) interaction database. RAID intends to provide the scientific community with all-in-one resources for efficient browsing and extraction of the RNA-associated interactions in human. This version of RAID contains more than 6100 RNA-associated interactions obtained by manually reviewing more than 2100 published papers, including 4493 RNA-RNA interactions and 1619 RNA-protein interactions. Each entry contains detailed information on an RNA-associated interaction, including RAID ID, RNA/protein symbol, RNA/protein categories, validated method, expressing tissue, literature references (Pubmed IDs), and detailed functional description. Users can query, browse, analyze, and manipulate RNA-associated (RNA-RNA/RNA-protein) interaction. RAID provides a comprehensive resource of human RNA-associated (RNA-RNA/RNA-protein) interaction network. Furthermore, this resource will help in uncovering the generic organizing principles of cellular function network.

  3. The Role of Shear-Thickening Fluids (STFs) in Ballistic and Stab-Resistance Improvement of Flexible Armor

    NASA Astrophysics Data System (ADS)

    Hasanzadeh, M.; Mottaghitalab, V.

    2014-04-01

    This paper provides a detailed review on relevant literature related to rheological properties of STFs with particular emphasis on efforts to improve their impact resistance. The review has concisely demonstrated that there are many factors affecting shear-thickening behavior of colloidal suspensions. Nanoparticle characteristics such as shape, size, distribution, solid volume fraction, and interaction with other particles as well as properties related to suspending phase and also flow field could affect the rheological properties of STFs. Recent studies on application of STFs to textile fabrics, preparation techniques, and the factors determining the performance of STF/fabric composites are summarized. Particular emphasis is laid on researches that explore the ballistic, stab, and puncture protective properties of STF-based materials and body armors.

  4. A Residual Mass Ballistic Testing Method to Compare Armor Materials or Components (Residual Mass Ballistic Testing Method)

    SciTech Connect

    Benjamin Langhorst; Thomas M Lillo; Henry S Chu

    2014-05-01

    A statistics based ballistic test method is presented for use when comparing multiple groups of test articles of unknown relative ballistic perforation resistance. The method is intended to be more efficient than many traditional methods for research and development testing. To establish the validity of the method, it is employed in this study to compare test groups of known relative ballistic performance. Multiple groups of test articles were perforated using consistent projectiles and impact conditions. Test groups were made of rolled homogeneous armor (RHA) plates and differed in thickness. After perforation, each residual projectile was captured behind the target and its mass was measured. The residual masses measured for each test group were analyzed to provide ballistic performance rankings with associated confidence levels. When compared to traditional V50 methods, the residual mass (RM) method was found to require fewer test events and be more tolerant of variations in impact conditions.

  5. Morphological and hematological studies of Trypanosoma spp. infecting ornamental armored catfish from Guamá River-PA, Brazil.

    PubMed

    Fujimoto, Rodrigo Y; Neves, Mikaelle S; Santos, Rudã F B; Souza, Natalino C; Do Couto, Márcia V S; Lopes, Josiane N S; Diniz, Daniel G; Eiras, Jorge C

    2013-09-01

    A total of 281 specimens of freshwater armored ornamental fish species (Leporacanthicus galaxias,Lasiancistrus saetiger, Cochliodon sp., Hypostomus sp., Pseudacanthicus spinosus, Ancistrus sp. and Rineloricaria cf. lanceolata) were captured at the hydrological basin of Guamá River, Pará, Brazil. The infection by Trypanosoma spp. was inspected. The morphological and morphometric characterization of the parasites and the hematological parameters were determined. Leporacanthicus galaxias and Pseudacanthicus spinosus presented 100% infection prevalence, and the other species showed a variable prevalence of infection. The parasites showed clearly different morphotypes and dimensions, and probably belong to different species. The hematological response to the infection varied with the host. Cochliodon sp. showed no differences between infected and not infected fish. In other species several modifications on some hematological parameters were found, but apparently without causing disease. It is emphasized the possibility of introduction of the parasites in new environments due to the artificial movements of these ornamental fish.

  6. Interactions between non-native armored suckermouth catfish (Loricariidae: Pterygoplichthys) and native Florida manatee (Trichechus manatus latirostris) in artesian springs

    USGS Publications Warehouse

    Nico, Leo G.; Loftus, William F.; Reid, James P.

    2009-01-01

    Non-native suckermouth armored catfishes (Loricariidae) of the genus Pterygoplichthys are now common throughout much of peninsular Florida. In this paper, we present preliminary observations on interactions between a Pterygoplichthys species, tentatively identified as P. disjunctivus (Weber, 1991), and endangered native Florida manatees, Trichechus manatus latirostris (Harlan, 1824), in artesian spring systems in Florida's St. Johns River drainage. The introduced catfish have become abundant in spring habitats, sites used by manatees as winter thermal refuges. In the spring runs, Pterygoplichthys regularly attaches to manatees and grazes the epibiota on their skin. On occasion, dozens of Pterygoplichthys congregate on individual manatees. Manatee responses varied widely; some did not react visibly to attached catfish whereas others appeared agitated and attempted to dislodge the fish. The costs and/or benefits of this interaction to manatees remain unclear.

  7. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of Mil A46100 Armor-Grade Steel: A Computational Investigation

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Snipes, J. S.; Galgalikar, R.; Ramaswami, S.; Yavari, R.; Yen, C.-F.; Cheeseman, B. A.

    2014-09-01

    In our recent work, a multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process was introduced. The model is of a modular type and comprises five modules, each designed to handle a specific aspect of the GMAW process, i.e.: (i) electro-dynamics of the welding-gun; (ii) radiation-/convection-controlled heat transfer from the electric-arc to the workpiece and mass transfer from the filler-metal consumable electrode to the weld; (iii) prediction of the temporal evolution and the spatial distribution of thermal and mechanical fields within the weld region during the GMAW joining process; (iv) the resulting temporal evolution and spatial distribution of the material microstructure throughout the weld region; and (v) spatial distribution of the as-welded material mechanical properties. In the present work, the GMAW process model has been upgraded with respect to its predictive capabilities regarding the spatial distribution of the mechanical properties controlling the ballistic-limit (i.e., penetration-resistance) of the weld. The model is upgraded through the introduction of the sixth module in the present work in recognition of the fact that in thick steel GMAW weldments, the overall ballistic performance of the armor may become controlled by the (often inferior) ballistic limits of its weld (fusion and heat-affected) zones. To demonstrate the utility of the upgraded GMAW process model, it is next applied to the case of butt-welding of a prototypical high-hardness armor-grade martensitic steel, MIL A46100. The model predictions concerning the spatial distribution of the material microstructure and ballistic-limit-controlling mechanical properties within the MIL A46100 butt-weld are found to be consistent with prior observations and general expectations.

  8. Messenger RNA degradation in bacterial cells.

    PubMed

    Hui, Monica P; Foley, Patricia L; Belasco, Joel G

    2014-01-01

    mRNA degradation is an important mechanism for controlling gene expression in bacterial cells. This process involves the orderly action of a battery of cellular endonucleases and exonucleases, some universal and others present only in certain species. These ribonucleases function with the assistance of ancillary enzymes that covalently modify the 5' or 3' end of RNA or unwind base-paired regions. Triggered by initiating events at either the 5' terminus or an internal site, mRNA decay occurs at diverse rates that are transcript specific and governed by RNA sequence and structure, translating ribosomes, and bound sRNAs or proteins. In response to environmental cues, bacteria are able to orchestrate widespread changes in mRNA lifetimes by modulating the concentration or specific activity of cellular ribonucleases or by unmasking the mRNA-degrading activity of cellular toxins.

  9. RNA as an Enzyme.

    ERIC Educational Resources Information Center

    Cech, Thomas R.

    1986-01-01

    Reviews current findings that explain RNA's function as an enzyme in addition to being an informational molecule. Highlights recent research efforts and notes changes in the information base on RNA activity. Includes models and diagrams of RNA activity. (ML)

  10. Meralgia paresthetica due to body armor wear in U.S. soldiers serving in Iraq: a case report and review of the literature.

    PubMed

    Fargo, Matthew V; Konitzer, Lisa N

    2007-06-01

    Meralgia paresthetica is a disorder of the lateral femoral cutaneous nerve that results in symptoms of anterolateral thigh paresthesias and dysesthesias without associated loss of reflexes or motor weakness. Chronic meralgia paresthetica, not related to traumatic or lesion-producing compression of the nerve, is associated with obesity, pregnancy, tight-fitting garments, as well as specific duty uniform belts used by police officers and carpenters. Cases are presented in which two U.S. soldiers in Iraq experienced symptoms of meralgia paresthetica, most likely due to repetitive wear of protective body armor. Although use of protective body armor is proven to be lifesaving, modifications to improve current equipment may help to decrease morbidities such as meralgia paresthetica.

  11. In vivo single-RNA tracking shows that most tRNA diffuses freely in live bacteria

    PubMed Central

    Plochowietz, Anne; Farrell, Ian; Smilansky, Zeev; Cooperman, Barry S.; Kapanidis, Achillefs N.

    2017-01-01

    Transfer RNA (tRNA) links messenger RNA nucleotide sequence with amino acid sequence during protein synthesis. Despite the importance of tRNA for translation, its subcellular distribution and diffusion properties in live cells are poorly understood. Here, we provide the first direct report on tRNA diffusion localization in live bacteria. We internalized tRNA labeled with organic fluorophores into live bacteria, applied single-molecule fluorescence imaging with single-particle tracking and localized and tracked single tRNA molecules over seconds. We observed two diffusive species: fast (with a diffusion coefficient of ∼8 μm2/s, consistent with free tRNA) and slow (consistent with tRNA bound to larger complexes). Our data indicate that a large fraction of internalized fluorescent tRNA (>70%) appears to diffuse freely in the bacterial cell. We also obtained the subcellular distribution of fast and slow diffusing tRNA molecules in multiple cells by normalizing for cell morphology. While fast diffusing tRNA is not excluded from the bacterial nucleoid, slow diffusing tRNA is localized to the cell periphery (showing a 30% enrichment versus a uniform distribution), similar to non-uniform localizations previously observed for mRNA and ribosomes. PMID:27625389

  12. Effects of First Underlayer Weight on the Stability of Stone-Armored, Rubble-Mound Breakwater Trunks Subjected to Nonbreaking Waves with No Overtopping. Hydraulic Model Investigation.

    DTIC Science & Technology

    1980-01-01

    Experiment Station, CE, Vicksburg, Miss. Carver, R. D., and Davidson, D. D. 1976. "Stability of Rubble-Mound Breakwater, Jubail Harbor, Saudi Arabia ...types of armor units were tested: smooth quarrystones (basalt), rough quarry- stones ( granite ), tetrapods, quadripods, tribars, modified cubes, hexa...electrical output of the wave gages was directly proportional to their submergence depth. Materials used 23. Rough granite stone (W ) with an average

  13. Armored CAR T-cells: utilizing cytokines and pro-inflammatory ligands to enhance CAR T-cell anti-tumour efficacy.

    PubMed

    Yeku, Oladapo O; Brentjens, Renier J

    2016-04-15

    Chimaeric antigen receptor (CAR) T-cells are T-cells that have been genetically modified to express an artificial construct consisting of a synthetic T-cell receptor (TCR) targeted to a predetermined antigen expressed on a tumour. Coupling the T-cell receptor to a CD3ζ signalling domain paved the way for first generation CAR T-cells that were efficacious against cluster of differentiation (CD)19-expressing B-cell malignancies. Optimization with additional signalling domains such as CD28 or 4-1BB in addition to CD3ζ provided T-cell activation signal 2 and further improved the efficacy and persistence of these second generation CAR T-cells. Third generation CAR T-cells which utilize two tandem costimulatory domains have also been reported. In this review, we discuss a different approach to optimization of CAR T-cells. Through additional genetic modifications, these resultant armored CAR T-cells are typically modified second generation CAR T-cells that have been further optimized to inducibly or constitutively secrete active cytokines or express ligands that further armor CAR T-cells to improve efficacy and persistence. The choice of the 'armor' agent is based on knowledge of the tumour microenvironment and the roles of other elements of the innate and adaptive immune system. Although there are several variants of armored CAR T-cells under investigation, here we focus on three unique approaches using interleukin-12 (IL-12), CD40L and 4-1BBL. These agents have been shown to further enhance CAR T-cell efficacy and persistence in the face of a hostile tumour microenvironment via different mechanisms.

  14. Monitoring lingering oil from the Exxon Valdez spill on Gulf of Alaska armored beaches and mussel beds sixteen years post-spill

    USGS Publications Warehouse

    Irvine, G.V.; Mann, D.H.; Short, J.W.

    2008-01-01

    Final Rept. ; Prepared in Cooperation With Alaska Univ., Fairbanks. Inst. of Arctic Biology. Sponsored By National Marine Fisheries Service, Juneau, Ak. AlaskaFisheries Science Center. ; Stranded Exxon Valdez Oil Has Persisted for 16 Years At Boulder-Armored Beach Sites Along National Park Coastlines Bordering the Gulf of Alaska. These Sites Are Up to 640 Km From the Spill Origin and Were Contaminated By Oil Mousse, a Viscous Water-in-Oil Emulsion. Although Surface Oil Has Continued to Decline, Subsurface Oiling Persists in Patches. Especially Striking Is the General Lack of Weathering of Stranded Oil on Armored Beaches Over the Last 16 Years. At Three of the Four Sites Where Oil Was Sampled in 2005, the Oil Was Compositionally Similar to 11-Day Old Exxon Valdez Oil, Even After 16 Years. The Formation of Mousse Allowed Less-Weathered Oil to Be Transported Long Distances. The Sequestration of the Oil Beneath a Boulder Armor, Coupled With the Stability of the Boulder Armoring (Investigated By Examining Movement of Marked Boulders), Had Contributed to the Lengthy Persistence of This Stranded Oil. Opportunistic Sampling of Several Previously Studied Oiled Mussel Beds Indicates Continued Contamination of At Least One of the Sites By Not Very Weathered Exxon Valdez Oil. Long-Term Persistence of Oil in These Habitats Should Cause Reconsideration of Response Activities After Spills, and May Influence the Environmental Sensitivity Indices Applied to These Habitats. 

  15. Alkane-modified short polyethyleneimine for siRNA delivery.

    PubMed

    Schroeder, Avi; Dahlman, James E; Sahay, Gaurav; Love, Kevin T; Jiang, Shan; Eltoukhy, Ahmed A; Levins, Christopher G; Wang, Yingxia; Anderson, Daniel G

    2012-06-10

    RNA interference (RNAi) is a highly specific gene-silencing mechanism triggered by small interfering RNA (siRNA). Effective intracellular delivery requires the development of potent siRNA carriers. Here, we describe the synthesis and screening of a series of siRNA delivery materials. Short polyethyleneimine (PEI, Mw 600) was selected as a cationic backbone to which lipid tails were conjugated at various levels of saturation. In solution these polymer-lipid hybrids self-assemble to form nanoparticles capable of complexing siRNA. The complexes silence genes specifically and with low cytotoxicity. The efficiency of gene knockdown increased as the number of lipid tails conjugated to the PEI backbone increased. This is explained by reducing the binding affinity between the siRNA strands to the complex, thereby enabling siRNA release after cellular internalization. These results highlight the importance of complexation strength when designing siRNA delivery materials.

  16. Formation of lobate debris aprons on Mars: Assessment of regional ice sheet collapse and debris-cover armoring

    NASA Astrophysics Data System (ADS)

    Fastook, James L.; Head, James W.; Marchant, David R.

    2014-01-01

    Lobate debris aprons (LDA) are lobate-shaped aprons surrounding scarps and isolated massifs that are concentrated in the vicinity of the northern Dichotomy Boundary on Mars. LDAs have been interpreted as (1) ice-cemented talus aprons undergoing viscous flow, (2) local debris-covered alpine-like glaciers, or (3) remnants of the collapse of a regional retreating ice sheet. We investigate the plausibility that LDAs are remnants of a more extensive regional ice sheet by modeling this process. We find that as a regional ice sheet collapses, the surface drops below cliff and massif bedrock margins, exposing bedrock and regolith, and initiating debris deposition on the surface of a cold-based glacier. Reduced sublimation due to debris-cover armoring of the proto-LDA surface produces a surface slope and consequent ice flow that carries the armoring debris away from the rock outcrops. As collapse and ice retreat continue the debris train eventually reaches the substrate surface at the front of the glacier, leaving the entire LDA armored by debris cover. Using a simplified ice flow model we are able to characterize the temperature and sublimation rate that would be necessary to produce LDAs with a wide range of specified lateral extents and thicknesses. We then apply this method to a database of documented LDA parameters (height, lateral extent) from the Dichotomy Boundary region, and assess the implications for predicted climate conditions during their formation and the range of formation times implied by the model. We find that for the population examined here, typical temperatures are in the range of -85 to -40 °C and typical sublimation rates lie in the range of 6-14 mm/a. Lobate debris apron formation times (from the point of bedrock exposure to complete debris cover) cluster near 400-500 ka. These results show that LDA length and thickness characteristics are consistent with climate conditions and a formation scenario typical of the collapse of a regional retreating

  17. T7-RNA Polymerase

    NASA Technical Reports Server (NTRS)

    1997-01-01

    T7-RNA Polymerase grown on STS-81. Structure-Function Relationships of RNA Polymerase: DNA-dependent RNA polymerase is the key enzyme responsible for the biosynthesis of RNA, a process known as transcription. Principal Investigator's include Dr. Dan Carter, Dr. B.C. Wang, and Dr. John Rose of New Century Pharmaceuticals.

  18. Automated classification of RNA 3D motifs and the RNA 3D Motif Atlas.

    PubMed

    Petrov, Anton I; Zirbel, Craig L; Leontis, Neocles B

    2013-10-01

    The analysis of atomic-resolution RNA three-dimensional (3D) structures reveals that many internal and hairpin loops are modular, recurrent, and structured by conserved non-Watson-Crick base pairs. Structurally similar loops define RNA 3D motifs that are conserved in homologous RNA molecules, but can also occur at nonhomologous sites in diverse RNAs, and which often vary in sequence. To further our understanding of RNA motif structure and sequence variability and to provide a useful resource for structure modeling and prediction, we present a new method for automated classification of internal and hairpin loop RNA 3D motifs and a new online database called the RNA 3D Motif Atlas. To classify the motif instances, a representative set of internal and hairpin loops is automatically extracted from a nonredundant list of RNA-containing PDB files. Their structures are compared geometrically, all-against-all, using the FR3D program suite. The loops are clustered into motif groups, taking into account geometric similarity and structural annotations and making allowance for a variable number of bulged bases. The automated procedure that we have implemented identifies all hairpin and internal loop motifs previously described in the literature. All motif instances and motif groups are assigned unique and stable identifiers and are made available in the RNA 3D Motif Atlas (http://rna.bgsu.edu/motifs), which is automatically updated every four weeks. The RNA 3D Motif Atlas provides an interactive user interface for exploring motif diversity and tools for programmatic data access.

  19. Automated classification of RNA 3D motifs and the RNA 3D Motif Atlas

    PubMed Central

    Petrov, Anton I.; Zirbel, Craig L.; Leontis, Neocles B.

    2013-01-01

    The analysis of atomic-resolution RNA three-dimensional (3D) structures reveals that many internal and hairpin loops are modular, recurrent, and structured by conserved non-Watson–Crick base pairs. Structurally similar loops define RNA 3D motifs that are conserved in homologous RNA molecules, but can also occur at nonhomologous sites in diverse RNAs, and which often vary in sequence. To further our understanding of RNA motif structure and sequence variability and to provide a useful resource for structure modeling and prediction, we present a new method for automated classification of internal and hairpin loop RNA 3D motifs and a new online database called the RNA 3D Motif Atlas. To classify the motif instances, a representative set of internal and hairpin loops is automatically extracted from a nonredundant list of RNA-containing PDB files. Their structures are compared geometrically, all-against-all, using the FR3D program suite. The loops are clustered into motif groups, taking into account geometric similarity and structural annotations and making allowance for a variable number of bulged bases. The automated procedure that we have implemented identifies all hairpin and internal loop motifs previously described in the literature. All motif instances and motif groups are assigned unique and stable identifiers and are made available in the RNA 3D Motif Atlas (http://rna.bgsu.edu/motifs), which is automatically updated every four weeks. The RNA 3D Motif Atlas provides an interactive user interface for exploring motif diversity and tools for programmatic data access. PMID:23970545

  20. Analysis of recurring sinking events of armored tracked vehicles along dirt roads in the agricultural periphery of the Gaza Strip

    NASA Astrophysics Data System (ADS)

    Roskin, Joel

    2013-04-01

    The second (Al-Aqsa) intifada (Arab violent uprising) which erupted across Israel in 2000 eventually led the Israel Defense Forces to deploy armored tracked vehicles (ATVs) (tanks, armored personal carriers, and D-9 bulldozers) within Israel's agricultural periphery of the Gaza Strip, following daily attempts by Arab terrorists and guerillas to penetrate Israel. Combat movement of the ATVs was mainly concentrated to dirt roads, between agricultural fields, wherever possible. As a result of semi-arid Mediterranean (climate) winter rains, annually averaging 250 - 350 mm, it was reported that ATVs often sank in muddy terrain. This study investigated what caused ATVs to sink. The main data collected concerning the types of vehicles that sank related to: land-use characteristics, soil type, and daily rainfall. Interviews with commanders were also conducted for additional details. Between the fall and spring, surveys and weekly / bi-weekly field soil cone penetrometer tests were conducted at ten sites with different pedological and land-use characteristics. The loess soils, especially in agricultural fields, were generally found to be conducive to ATV traffic, even shortly after rainstorms of 10-30 mm. However, following several rainfall events exceeding 10 mm, ATVs and tanks regularly sank into local topographic depressions in the undulating landscape. These consisted of short segments of dirt roads where runoff and suspended sediment collected. After the early rains in late fall, tank ruts fossilize and become conduits of concentrated runoff and fine particles eroded by ATV activity during the summer months. Tank track ruts that formed in mud, compacted the soil, drastically altered drainage patterns by directing significant surface flow, and suspended sediment into these depressions, creating "tank-traps" whose trafficability ranged from "untrafficable" to "trafficable with constraints." This study shows that intense, routine, defensive military activity operated

  1. Replication of Tobamovirus RNA.

    PubMed

    Ishibashi, Kazuhiro; Ishikawa, Masayuki

    2016-08-04

    Tobacco mosaic virus and other tobamoviruses have served as models for studying the mechanisms of viral RNA replication. In tobamoviruses, genomic RNA replication occurs via several steps: (a) synthesis of viral replication proteins by translation of the genomic RNA; (b) translation-coupled binding of the replication proteins to a 5'-terminal region of the genomic RNA; (c) recruitment of the genomic RNA by replication proteins onto membranes and formation of a complex with host proteins TOM1 and ARL8; (d) synthesis of complementary (negative-strand) RNA in the complex; and (e) synthesis of progeny genomic RNA. This article reviews current knowledge on tobamovirus RNA replication, particularly regarding how the genomic RNA is specifically selected as a replication template and how the replication proteins are activated. We also focus on the roles of the replication proteins in evading or suppressing host defense systems.

  2. Modeling the Biodynamical Response of the Human Thorax with Body Armor from a Bullet Impact

    DTIC Science & Technology

    2001-03-01

    are continuous with the osseous tissue of the rib that it belongs to. The inner extremity of the coastal cartilage for the first rib pair is... accidents , led to additional developments of the finite element model of the thorax. Chen [Ref. 61 developed a finite element model of the human thorax... accident . Their model assumed linear elastic material properties except for the internal organs that were modeled as a viscoelastic material. Their

  3. Extracellular RNA in aging.

    PubMed

    Dluzen, Douglas F; Noren Hooten, Nicole; Evans, Michele K

    2017-03-01

    Since the discovery of extracellular RNA (exRNA) in circulation and other bodily fluids, there has been considerable effort to catalog and assess whether exRNAs can be used as markers for health and disease. A variety of exRNA species have been identified including messenger RNA and noncoding RNA such as microRNA (miRNA), small nucleolar RNA, transfer RNA, and long noncoding RNA. Age-related changes in exRNA abundance have been observed, and it is likely that some of these transcripts play a role in aging. In this review, we summarize the current state of exRNA profiling in various body fluids and discuss age-related changes in exRNA abundance that have been identified in humans and other model organisms. miRNAs, in particular, are a major focus of current research and we will highlight and discuss the potential role that specific miRNAs might play in age-related phenotypes and disease. We will also review challenges facing this emerging field and various strategies that can be used for the validation and future use of exRNAs as markers of aging and age-related disease. WIREs RNA 2017, 8:e1385. doi: 10.1002/wrna.1385 For further resources related to this article, please visit the WIREs website.

  4. Titanosaur Osteoderms from the Upper Cretaceous of Lo Hueco (Spain) and Their Implications on the Armor of Laurasian Titanosaurs

    PubMed Central

    Vidal, Daniel; Ortega, Francisco; Sanz, José Luis

    2014-01-01

    Titanosaurs are the only sauropod dinosaurs known to bear a dermal armor. Their osteoderms are relatively rare finds, with few more than a hundred specimens recovered worldwide. Also, little is known about their intra-individual, intra-specific or inter-specific variability. The macrovertebrate site of Lo Hueco (Upper Cretaceous; Cuenca, Spain) has yielded several complete specimens of osteoderms, some associated with fairly articulated specimens. They are all variations of the morphotype known as bulb and root. The presence of only this morphotype in Europe, which is considered as the primitive condition among titanosaurs, seems to indicate that the known Upper Cretaceous Laurasian titanosaurs only bore these referred bulb and root osteoderms. An eliptic Fourier analysis on the outline of complete specimens from this morphotype reveals: i) that they truly are part of a morphological cline; and ii) the existence of a consistent correlation between the outline and the morphology of the bulb. Such variation along a cline is more consistent with intra-individual rather than inter-specific variation. The osteoderms associated with a single titanosaur individual from Lo Hueco reinforce this hypothesis. PMID:25118985

  5. Preliminary survey report: evaluation of brake-drum-service controls at US Army Armor Center, Fort Knox, Kentucky

    SciTech Connect

    Godbey, F.W.

    1988-08-01

    A visit was made to the U.S. Army Armor Center, Fort Knox, Kentucky, as part of a study of asbestos hazards encountered during the maintenance and repair of vehicular brakes. Approximately 800 vehicles were maintained at the center each year with about 100 brake jobs being needed during that course of time. Exposure to asbestos may occur during cleaning, maintenance, and repair of brakes. Workers were encouraged to use good work practices including the complete water rinsing and wet-bristle brushing of all exposed parts prior to handling, gently removing and handling all parts, consistently using all required personal protective equipment, and following instructions for use of asbestos-control devices. Annual physical examinations were provided for workers performing vehicular brake-repair services. The author concludes that the facility did not appear to have asbestos controls sufficient to protect the workers from asbestos dust arising from service operations. The advisability of conducting an in depth evaluation of the controls at the facility will be made in the future, after all the preliminary surveys and finalization of the protocol for the project has been reached.

  6. Long-term survivability of riprap for armoring uranium-mill tailings and covers: a literature review. [203 references

    SciTech Connect

    Lindsey, C.G.; Long, L.W.; Begej, C.W.

    1982-06-01

    Pacific Northwest Laboratory (PNL) is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon suppression cover applied to uranium mill tailings. Because the radon suppression cover and the tailings must remain intact for up to 1000 years or longer, the riprap must withstand natural weathering forces. This report is a review of information on rock weathering and riprap durability. Chemical and physical weathering processes, rock characteristics related to durability, climatic conditions affecting the degree and rate of weathering, and testing procedures used to measure weathering susceptibilities have been reviewed. Sampling and testing techniques, as well as analyses of physical and chemical weathering susceptibilities, are necessary to evaluate rock durability. Many potential riprap materials may not be able to survive 1000 years of weathering. Available techniques for durability testing cannot adequately predict rock durability for the 1000-year period because they do not consider the issue of time (i.e., how long must riprap remain stable). This report includes an Appendix, which discusses rock weathering, written by Dr. Richard Jahns of Stanford University.

  7. Water-assisted self-healing and property recovery in a natural dermal armor of pangolin scales.

    PubMed

    Liu, Z Q; Jiao, D; Weng, Z Y; Zhang, Z F

    2016-03-01

    Self-healing capacity, of which the inspiration comes from biological systems, is significant for restoring the mechanical properties of materials by autonomically repairing damages. Clarifying the naturally occurring self-healing behaviors and mechanisms may provide valuable inspiration for designing synthetic self-healing materials. In this study, water-assisted self-healing behavior was revealed in a natural dermal armor of pangolin scales. The indentation damages which imitate the injury caused by predatory attack can be continuously mitigated through hydration. The healing kinetics was characterized according to the variations of indentation crater dimension and quantitatively described in terms of the viscoelastic behavior of biopolymer. The mechanical properties of original, damaged, and recovered scales in both dry and wet states were systematically evaluated by three-point bending and compared through statistical analysis. The hydration effects and mechanisms were explored by examining the dynamic mechanical properties and thermal behaviors. The promoted self-healing process can be attributed to the improved flexibility of macromolecules in the biopolymer. This study may stimulate useful self-healing strategies in bio-inspired design and aid in developing high-performance synthetic self-healing materials.

  8. Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends.

    PubMed

    Nogueira, Lílian; da Silva, Danilo Grünig Humberto; Oliveira, Thiago Yukio Kikuchi; da Rosa, Joel Maurício Correa; Felício, Andréia Arantes; de Almeida, Eduardo Alves

    2013-09-01

    Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7d to 0.01mLL(-1) and 0.1mLL(-1) of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2'-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota.

  9. Extensive jaw mobility in suckermouth armored catfishes (Loricariidae): a morphological and kinematic analysis of substrate scraping mode of feeding.

    PubMed

    Adriaens, Dominique; Geerinckx, Tom; Vlassenbroeck, Jelle; Van Hoorebeke, Luc; Herrel, Anthony

    2009-01-01

    Loricariidae, or suckermouth armored catfishes, possess upper and lower jaws that are ventrally oriented and that bear teeth that touch the substrate from which algae and other food items are scraped. The ventral orientation and the highly specialized morphology of the jaws, characterized by protrusible upper jaws and left-right decoupled lower jaws, are observed in Pterygoplichthys disjunctivus, the species investigated here. Kinematic data of the scraping feeding movements, obtained by external high-speed and x-ray recordings, are used to quantify jaw movement, especially to test for upper jaw mobility and versatility during substrate scraping. Our results show that the mobility of the jaws is indeed high compared with what is standard for catfishes. The upper jaw's ability to perform a substantial degree of rostrocaudal movement is quite unique for catfishes. The ventromedially oriented lower jaws, with the teeth and the coronoid process at opposite sides, display an extensive mobility: they rotate around the suspensorial articulation and around their longitudinal axis, resulting in an extended scraping movement and thereby covering a large surface area. The lower jaws also show a left-right asymmetry in their movements during scraping. Thus, our results suggest that the extreme morphological specializations of the jaws in loricariid catfishes are linked to an increased mobility and functional versatility, allowing these animals to efficiently scrape algae from substrates with irregular surfaces.

  10. Designing Efficient Double RNA trans-Splicing Molecules for Targeted RNA Repair

    PubMed Central

    Hüttner, Clemens; Murauer, Eva M.; Hainzl, Stefan; Kocher, Thomas; Neumayer, Anna; Reichelt, Julia; Bauer, Johann W.; Koller, Ulrich

    2016-01-01

    RNA trans-splicing is a promising tool for mRNA modification in a diversity of genetic disorders. In particular, the substitution of internal exons of a gene by combining 3′ and 5′ RNA trans-splicing seems to be an elegant way to modify especially large pre-mRNAs. Here we discuss a robust method for designing double RNA trans-splicing molecules (dRTM). We demonstrate how the technique can be implemented in an endogenous setting, using COL7A1, the gene encoding type VII collagen, as a target. An RTM screening system was developed with the aim of testing the replacement of two internal COL7A1 exons, harbouring a homozygous mutation, with the wild-type version. The most efficient RTMs from a pool of randomly generated variants were selected via our fluorescence-based screening system and adapted for use in an in vitro disease model system. Transduction of type VII collagen-deficient keratinocytes with the selected dRTM led to accurate replacement of two internal COL7A1 exons resulting in a restored wild-type RNA sequence. This is the first study demonstrating specific exon replacement by double RNA trans-splicing within an endogenous transcript in cultured cells, corroborating the utility of this technology for mRNA repair in a variety of genetic disorders. PMID:27669223

  11. Antibodies against RNA hydrolyze RNA and DNA.

    PubMed

    Krasnorutskii, Michael A; Buneva, Valentina N; Nevinsky, Georgy A

    2008-01-01

    Immunization of animals with DNA leads to the production of anti-DNA antibodies (Abs) demonstrating both DNase and RNase activities. It is currently not known whether anti-RNA Abs can possess nuclease activities. In an attempt to address this question, we have shown that immunization of three rabbits with complex of RNA with methylated BSA (mBSA) stimulates production of IgGs with RNase and DNase activities belonging to IgGs, while polyclonal Abs from three non-immunized rabbits and three animals immunized with mBSA are catalytically inactive. Affinity chromatography of IgGs from the sera of autoimmune (AI) patients on DNA-cellulose usually demonstrates a number of fractions, all of which effectively hydrolyze both DNA and RNA, while rabbit catalytic IgGs were separated into Ab subfractions, some of which demonstrated only DNase activity, while others hydrolyzed RNA faster than DNA. The enzymic properties of the RNase and DNase IgGs from rabbits immunized with RNA distinguish them from all known canonical RNases and DNases and DNA- and RNA-hydrolyzing abzymes (Abzs) from patients with different AI diseases. In contrast to RNases and AI RNA-hydrolyzing Abs, rabbit RNase IgGs catalyze only the first step of the hydrolysis reaction but cannot hydrolyze the formed terminal 2',3'-cyclophosphate. The data indicate that Abzs of AI patients hydrolyzing nucleic acids in part may be Abs against RNA and its complexes with proteins.

  12. RNA-Catalyzed RNA Ligation on an External RNA Template

    NASA Technical Reports Server (NTRS)

    McGinness, Kathleen E.; Joyce, Gerald F.

    2002-01-01

    Variants of the hc ligase ribozyme, which catalyzes ligation of the 3' end of an RNA substrate to the 5' end of the ribozyme, were utilized to evolve a ribozyme that catalyzes ligation reactions on an external RNA template. The evolved ribozyme catalyzes the joining of an oligonucleotide 3'-hydroxyl to the 5'-triphosphate of an RNA hairpin molecule. The ribozyme can also utilize various substrate sequences, demonstrating a largely sequence-independent mechanism for substrate recognition. The ribozyme also carries out the ligation of two oligonucleotides that are bound at adjacent positions on a complementary template. Finally, it catalyzes addition of mononucleoside '5-triphosphates onto the '3 end of an oligonucleotide primer in a template-dependent manner. The development of ribozymes that catalyze polymerase-type reactions contributes to the notion that an RNA world could have existed during the early history of life on Earth.

  13. RNA nanoparticle as a vector for targeted siRNA delivery into glioblastoma mouse model.

    PubMed

    Lee, Tae Jin; Haque, Farzin; Shu, Dan; Yoo, Ji Young; Li, Hui; Yokel, Robert A; Horbinski, Craig; Kim, Tae Hyong; Kim, Sung-Hak; Kwon, Chang-Hyuk; Nakano, Ichiro; Kaur, Balveen; Guo, Peixuan; Croce, Carlo M

    2015-06-20

    Systemic siRNA administration to target and treat glioblastoma, one of the most deadly cancers, requires robust and efficient delivery platform without immunogenicity. Here we report newly emerged multivalent naked RNA nanoparticle (RNP) based on pRNA 3-way-junction (3WJ) from bacteriophage phi29 to target glioblastoma cells with folate (FA) ligand and deliver siRNA for gene silencing. Systemically injected FA-pRNA-3WJ RNPs successfully targeted and delivered siRNA into brain tumor cells in mice, and efficiently reduced luciferase reporter gene expression (4-fold lower than control). The FA-pRNA-3WJ RNP also can target human patient-derived glioblastoma stem cells, thought to be responsible for tumor initiation and deadly recurrence, without accumulation in adjacent normal brain cells, nor other major internal organs. This study provides possible application of pRNA-3WJ RNP for specific delivery of therapeutics such as siRNA, microRNA and/or chemotherapeutic drugs into glioblastoma cells without inflicting collateral damage to healthy tissues.

  14. RNA nanoparticle as a vector for targeted siRNA delivery into glioblastoma mouse model

    PubMed Central

    Lee, Tae Jin; Haque, Farzin; Shu, Dan; Yoo, Ji Young; Li, Hui; Yokel, Robert A.; Horbinski, Craig; Kim, Tae Hyong; Kim, Sung-Hak; Kwon, Chang-Hyuk; Nakano, Ichiro; Kaur, Balveen; Guo, Peixuan; Croce, Carlo M.

    2015-01-01

    Systemic siRNA administration to target and treat glioblastoma, one of the most deadly cancers, requires robust and efficient delivery platform without immunogenicity. Here we report newly emerged multivalent naked RNA nanoparticle (RNP) based on pRNA 3-way-junction (3WJ) from bacteriophage phi29 to target glioblastoma cells with folate (FA) ligand and deliver siRNA for gene silencing. Systemically injected FA-pRNA-3WJ RNPs successfully targeted and delivered siRNA into brain tumor cells in mice, and efficiently reduced luciferase reporter gene expression (4-fold lower than control). The FA-pRNA-3WJ RNP also can target human patient-derived glioblastoma stem cells, thought to be responsible for tumor initiation and deadly recurrence, without accumulation in adjacent normal brain cells, nor other major internal organs. This study provides possible application of pRNA-3WJ RNP for specific delivery of therapeutics such as siRNA, microRNA and/or chemotherapeutic drugs into glioblastoma cells without inflicting collateral damage to healthy tissues. PMID:25885522

  15. RNA-protein interaction methods to study viral IRES elements.

    PubMed

    Francisco-Velilla, Rosario; Fernandez-Chamorro, Javier; Lozano, Gloria; Diaz-Toledano, Rosa; Martínez-Salas, Encarnación

    2015-12-01

    Translation control often takes place through the mRNA untranslated regions, involving direct interactions with RNA-binding proteins (RBPs). Internal ribosome entry site elements (IRESs) are cis-acting RNA regions that promote translation initiation using a cap-independent mechanism. A subset of positive-strand RNA viruses harbor IRESs as a strategy to ensure efficient viral protein synthesis. IRESs are organized in modular structural domains with a division of functions. However, viral IRESs vary in nucleotide sequence, secondary RNA structure, and transacting factor requirements. Therefore, in-depth studies are needed to understand how distinct types of viral IRESs perform their function. In this review we describe methods to isolate and identify RNA-binding proteins important for IRES activity, and to study the impact of RNA structure and RNA-protein interactions on IRES activity.

  16. New Low Temperature Processing for Boron Carbide/Aluminum Based Composite Armor

    DTIC Science & Technology

    1990-06-01

    powders has shown the surface to be domi- nated by the acidic properties of a boric acid overlayer.11.12 Inspection of Table 1 * Micron Separations, Inc...stainless steel pressure filter (see Appendix A). After ROC, about half of the gradient parts had laminar cracks between the 70/30 and 60/40 B4 C/Al...Metal MaIx Baked out greeliware were enclosed in fitted cans of low carbon steel or 1100 aluminum; internal spaces between the can and the parts were

  17. Decoding the RNA structurome

    PubMed Central

    Lu, Zhipeng; Chang, Howard Y

    2016-01-01

    Structures of RNA molecules are essential for their architectural, regulatory, and catalytic functions. Recent advances in high throughput sequencing enabled the development of methods for probing RNA structures on a transcriptome-wide scale – termed the RNA structurome. Here we review the state-of-the-art technologies for probing the RNA structurome, and highlight insights gained from these studies. We also point out the limits of current methods and discuss potential directions for future improvements. PMID:26923056

  18. RNA signal amplifier circuit with integrated fluorescence output.

    PubMed

    Akter, Farhima; Yokobayashi, Yohei

    2015-05-15

    We designed an in vitro signal amplification circuit that takes a short RNA input that catalytically activates the Spinach RNA aptamer to produce a fluorescent output. The circuit consists of three RNA strands: an internally blocked Spinach aptamer, a fuel strand, and an input strand (catalyst), as well as the Spinach aptamer ligand 3,5-difluoro-4-hydroxylbenzylidene imidazolinone (DFHBI). The input strand initially displaces the internal inhibitory strand to activate the fluorescent aptamer while exposing a toehold to which the fuel strand can bind to further displace and recycle the input strand. Under a favorable condition, one input strand was able to activate up to five molecules of the internally blocked Spinach aptamer in 185 min at 30 °C. The simple RNA circuit reported here serves as a model for catalytic activation of arbitrary RNA effectors by chemical triggers.

  19. Chromosomal characterization of armored catfish Harttia longipinna (Siluriformes, Loricariidae): first report of B chromosomes in the genus.

    PubMed

    Blanco, Daniel Rodrigues; Vicari, Marcelo Ricardo; Artoni, Roberto Ferreira; Traldi, Josiane Baccarin; Moreira-Filho, Orlando

    2012-09-01

    The B chromosomes are accessory elements that are widely distributed among eukaryotic genomes and often show non-Mendelian inheritance. They are considered dispensable for the growth, development, and reproduction of organisms. Some studies have suggested that these elements may affect sex determination. Harttia is a small armored catfish genus that shows sexual dimorphism, including hypertrophied odontodes on the pectoral fin spines and along the margins of the snout in mature males. They exhibit considerable karyotypic diversity with diploid number (2n) variation and heteromorphic sex system in H. carvalhoi. To date, no occurrences of B chromosomes in the Harttia genus were detected and no relation to sexual differentiation in Neotropical fish has been determined. To determine the validity of this claim, the present paper characterized specimens of Harttia longipinna by classical and molecular cytogenetic methods. The 2n found was 58 (16m + 12sm + 16st + 14a), but of the 50 specimens analyzed (30 male and 20 female), 23 specimens (16 males and seven females) show an intra-individual from 0 to 2 micro B chromosomes. The B chromosomes were completely heterochromatic. The single NORs were shown in the first acrocentric pair with silver staining and 18S rDNA probing. FISH performed with 5S rDNA probe showed a single cistron in the proximal region of the short arm of a small metacentric pair. Thus, the cytogenetic data obtained in this study of H. longipinna highlight the karyotypic diversity found within the genus Harttia, and represent the first description of B chromosomes for this genus.

  20. Cytoplasmic Z-RNA

    SciTech Connect

    Zarling, D.A.; Calhoun, C.J.; Hardin, C.C.; Zarling, A.H.

    1987-09-01

    Specific immunochemical probes for Z-RNA were generated and characterized to search for possible Z-RNA-like double helices in cells. Z-RNA was detected in the cytoplasm of fixed protozoan cells by immunofluorescence microscopy using these anti-Z-RNA IgCs. In contrast, autoimmune or experimentally elicited anti-DNA antibodies, specifically reactive with B-DNA or Z-DNA, stained the nuclei. Pre-or nonimmune IgGs did not bind to the cells. RNase A or T1 digestion eliminated anti-Z-RNA IgG binding to cytoplasmic determinants; however, DNase I or mung bean nuclease had no effect. Doxorubicin and ethidium bromide prevented anti-Z-RNA antibody binding; however, actinomycin D, which does not bind double-stranded RNA, did not. Anti-Z-RNA immunofluorescence was specifically blocked in competition assays by synthetic Z-RNA but not Z-DNA, A-RNA, or single-stranded RNAs. Thus, some cytoplasmic sequences in fixed cells exist in the left-handed Z-RNA conformation.