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Sample records for flying saucer attack

  1. Flying Saucer? Aliens?

    NASA Technical Reports Server (NTRS)

    1961-01-01

    No, it's not a flying saucer, it is the domed top to a 70 foot long vacuum tank at the Lewis Research Center's Electric Propulsion Laboratory, Cleveland, Ohio. The three technicians shown here in protective clothing had just emerged from within the tank where they had been cleaning in the toxic mercury atmosphere, left after ion engine testing in the tank. Lewis has since been renamed the John H. Glenn Research Center.

  2. The shadow of the Flying Saucer: A very low temperature for large dust grains

    NASA Astrophysics Data System (ADS)

    Guilloteau, S.; Piétu, V.; Chapillon, E.; Di Folco, E.; Dutrey, A.; Henning, T.; Semenov, D.; Birnstiel, T.; Grosso, N.

    2016-02-01

    Context. Dust determines the temperature structure of protoplanetary disks, however, dust temperature determinations almost invariably rely on a complex modeling of the Spectral Energy Distribution. Aims: We attempt a direct determination of the temperature of large grains emitting at mm wavelengths. Methods: We observe the edge-on dust disk of the Flying Saucer, which appears in silhouette against the CO J = 2-1 emission from a background molecular cloud in ρ Oph. The combination of velocity gradients due to the Keplerian rotation of the disk and intensity variations in the CO background as a function of velocity allows us to directly measure the dust temperature. The dust opacity can then be derived from the emitted continuum radiation. Results: The dust disk absorbs the radiation from the CO clouds at several velocities. We derive very low dust temperatures, 5 to 7 K at radii around 100 au, which is much lower than most model predictions. The dust optical depth is >0.2 at 230 GHz, and the scale height at 100 au is at least 8 au (best fit 13 au). However, the dust disk is very flat (flaring index -0.35), which is indicative of dust settling in the outer parts.

  3. FLYING SAUCER1 Is a Transmembrane RING E3 Ubiquitin Ligase That Regulates the Degree of Pectin Methylesterification in Arabidopsis Seed Mucilage[W

    PubMed Central

    Voiniciuc, Cătălin; Dean, Gillian H.; Griffiths, Jonathan S.; Kirchsteiger, Kerstin; Hwang, Yeen Ting; Gillett, Alan; Dow, Graham; Western, Tamara L.; Estelle, Mark; Haughn, George W.

    2013-01-01

    Pectins are complex polysaccharides that form the gel matrix of the primary cell wall and are abundant in the middle lamella that holds plant cells together. Their degree of methylesterification (DM) impacts wall strength and cell adhesion since unesterified pectin regions can cross-link via Ca2+ ions to form stronger gels. Here, we characterize flying saucer1 (fly1), a novel Arabidopsis thaliana seed coat mutant, which displays primary wall detachment, reduced mucilage extrusion, and increased mucilage adherence. These defects appear to result from a lower DM in mucilage and are enhanced by the addition of Ca2+ or completely rescued using alkaline Ca2+ chelators. FLY1 encodes a transmembrane protein with a RING-H2 domain that has in vitro E3 ubiquitin ligase activity. FLY1 is orthologous to TRANSMEMBRANE UBIQUITIN LIGASE1, a Golgi-localized E3 ligase involved in the quality control of membrane proteins in yeast. However, FLY1–yellow fluorescent protein (YFP) fusions are localized in punctae that are predominantly distinct from the Golgi and the trans-Golgi network/early endosome in the seed coat epidermis. Wortmannin treatment, which induces the fusion of late endosomes in plants, resulted in enlarged FLY1-YFP bodies. We propose that FLY1 regulates the DM of pectin in mucilage, potentially by recycling pectin methylesterase enzymes in the endomembrane system of seed coat epidermal cells. PMID:23482858

  4. Flying saucer1 is a transmembrane RING E3 ubiquitin ligase that regulates the degree of pectin methylesterification in Arabidopsis seed mucilage.

    PubMed

    Voiniciuc, Catalin; Dean, Gillian H; Griffiths, Jonathan S; Kirchsteiger, Kerstin; Hwang, Yeen Ting; Gillett, Alan; Dow, Graham; Western, Tamara L; Estelle, Mark; Haughn, George W

    2013-03-01

    Pectins are complex polysaccharides that form the gel matrix of the primary cell wall and are abundant in the middle lamella that holds plant cells together. Their degree of methylesterification (DM) impacts wall strength and cell adhesion since unesterified pectin regions can cross-link via Ca(2+) ions to form stronger gels. Here, we characterize flying saucer1 (fly1), a novel Arabidopsis thaliana seed coat mutant, which displays primary wall detachment, reduced mucilage extrusion, and increased mucilage adherence. These defects appear to result from a lower DM in mucilage and are enhanced by the addition of Ca(2+) or completely rescued using alkaline Ca(2+) chelators. FLY1 encodes a transmembrane protein with a RING-H2 domain that has in vitro E3 ubiquitin ligase activity. FLY1 is orthologous to TRANSMEMBRANE UBIQUITIN LIGASE1, a Golgi-localized E3 ligase involved in the quality control of membrane proteins in yeast. However, FLY1-yellow fluorescent protein (YFP) fusions are localized in punctae that are predominantly distinct from the Golgi and the trans-Golgi network/early endosome in the seed coat epidermis. Wortmannin treatment, which induces the fusion of late endosomes in plants, resulted in enlarged FLY1-YFP bodies. We propose that FLY1 regulates the DM of pectin in mucilage, potentially by recycling pectin methylesterase enzymes in the endomembrane system of seed coat epidermal cells. PMID:23482858

  5. Defense mechanisms in resistant wheat seedlings in response to hessian fly attack

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat – Hessian fly interaction follows a typical gene-for-gene model. Hessian fly larvae die in wheat plants carrying an effective resistance gene, or thrive in susceptible plants that carry no effective resistance gene. Here we found that gene sets affected by Hessian fly attack in resistant pla...

  6. High angle of attack flying qualities criteria for longitudinal rate command systems

    NASA Technical Reports Server (NTRS)

    Wilson, David J.; Citurs, Kevin D.; Davidson, John B.

    1994-01-01

    This study was designed to investigate flying qualities requirements of alternate pitch command systems for fighter aircraft at high angle of attack. Flying qualities design guidelines have already been developed for angle of attack command systems at 30, 45, and 60 degrees angle of attack, so this research fills a similar need for rate command systems. Flying qualities tasks that require post-stall maneuvering were tested during piloted simulations in the McDonnell Douglas Aerospace Manned Air Combat Simulation facility. A generic fighter aircraft model was used to test angle of attack rate and pitch rate command systems for longitudinal gross acquisition and tracking tasks at high angle of attack. A wide range of longitudinal dynamic variations were tested at 30, 45, and 60 degrees angle of attack. Pilot comments, Cooper-Harper ratings, and pilot induced oscillation ratings were taken from five pilots from NASA, USN, CAF, and McDonnell Douglas Aerospace. This data was used to form longitudinal design guidelines for rate command systems at high angle of attack. These criteria provide control law design guidance for fighter aircraft at high angle of attack, low speed flight conditions. Additional time history analyses were conducted using the longitudinal gross acquisition data to look at potential agility measures of merit and correlate agility usage to flying qualities boundaries. This paper presents an overview of this research.

  7. Prevention of sand fly attack by topical application of a permethrin/pyriproxyfen combination on dogs.

    PubMed

    Mercier, Patrick; Jasmin, Pierre; Sanquer, Annaelle

    2003-01-01

    Dogs are the primary domestic reservoir of Leishmania infantum, the parasite responsible for most cases of human visceral leishmaniasis. A strategy for the control of leishmaniasis would be to inhibit the sand fly bite. A study was designed to measure the prevention of the sand fly attack by spraying a combination of permethrin and pyriproxyfen on dogs artificially exposed to the vector of leishmaniasis. Eight dogs were individually challenged with 100 female sand flies for 1 hour on Days -7, 0, 7, 14, 21, and 28. Four dogs were randomly assigned to a control group and four dogs were treated with topically applied permethrin/pyriproxyfen on Day 0. After each exposure, sand flies were collected, counted, and scored as fed or unfed. Efficacy of the combination for prevention of feeding was based on the number of unfed sand flies (dead or alive). The combination of permethrin/pyriproxyfen demonstrated a significant (P <.05) repellent effect against Phlebotomus perniciosus bites as soon as it was sprayed on the dogs, and its repellent efficacy lasted at least for 28 days. The combination product provided significant (P <.05) knockdown activity against challenge with sand flies for 21 days in adult dogs and 14 days in puppies. These findings indicate that adult animals in endemic areas should be sprayed with the permethrin/pyriproxyfen product at 3- to 4-week intervals, and young dogs should be sprayed at approximately 2-week intervals, to prevent sand fly attack. PMID:15136993

  8. Solar breeze power package and saucer ship

    SciTech Connect

    Veazey, S. E.

    1985-11-12

    A solar breeze power package having versatile sail and windmast options useful both on land and sea and especially useful in the saucer ship type design. The Vertical Axis Wind Turbine (VAWT) of the several Darrieus designs in conjunction with roll-up or permanently mounted solar cells combine in a hybrid or are used separately to provide power to a battery bank or other storage device.

  9. The Aerodynamics of Axisymmetric Blunt Bodies Flying at Angle of Attack

    NASA Technical Reports Server (NTRS)

    Schoenenberger, Mark; Kutty, Prasad; Queen, Eric; Karlgaard, Chris

    2014-01-01

    The Mars Science Laboratory entry capsule is used as an example to demonstrate how a blunt body of revolution must be treated as asymmetric in some respects when flying at a non-zero trim angle of attack. A brief description of the axisymmetric moment equations are provided before solving a system of equations describing the lateral-directional moment equations for a blunt body trimming at an angle of attack. Simplifying assumptions are made which allow the solution to the equations to be rearranged to relate the roll and yaw stability with sideslip angle to the frequency of oscillation of the vehicle body rates. The equations show that for a blunt body the roll and yaw rates are in phase and proportional to each other. The ratio of the rates is determined by the static stability coefficients and mass properties about those axes. A trajectory simulation is used to validate the static yaw stability parameter identification equation and a simple method of identifying the oscillation frequency from the body rates. The approach is shown to successfully extract the modeled yaw stability coefficient along a simulated Mars entry in agreement with data earlier analysis of MSL flight data.

  10. Differential Accumulation of Phytohormones in Wheat Seedlings Attacked by Avirulent and Virulent Hessian Fly (Diptera: Cecidomyiidae) Larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We analyzed the accumulation of six phytohormones and phytohormone-related compounds in a wheat [Triticum aestivium (L.)] genotype ‘Molly’ following attacks by avirulent and virulent Hessian fly [Mayetiola destructor (Say)] larvae, respectively, and examined the expression of genes in the jasmonic a...

  11. Ion cyclotron bands in VLF saucers

    NASA Technical Reports Server (NTRS)

    Maeda, Kaichi; Fung, Shing F.; Calvert, Wynne

    1990-01-01

    In the wideband VLF data obtained by the polar orbiting DE-1 satellite over the polar night ion trough region of the upper ionosphere, conspicuous frequency-band structures are found to occur both in absorption and emission, particularly associating with VLF saucers. The attenuation bands indicate that the ions of atomic hydrogen from the polar ionosphere are accelerated by the ac electric fields of VLF waves oscillating normal to the static magnetic field, analogous to a cyclotron accelerator. The observed frequencies of the cyclotron harmonics suggest that the acceleration is taking place in the layer below the satellite at a geocentric distance of less than about 1.5 earth radii. This example indicates the existence of upward propagating hiss at those altitudes inside the auroral zone. On the other hand, the frequency shifts of the emission bands are attributed to a combination of two different types of Doppler shift, one due to the orbital motion of the satellite and the other due to the upward motion of the medium at the emission source. This indicates the existence of an upward plasma flow at the source, with a velocity of the order of 20 km/s inside the saucer. The amount of this frequency shift decreases with increasing harmonic order, indicating a higher phase velocity for the electrostatic waves of higher harmonic order.

  12. Cuticular Hydrocarbon Cues Are Used for Host Acceptance by Pseudacteon spp. Phorid Flies that Attack Azteca sericeasur Ants.

    PubMed

    Mathis, Kaitlyn A; Tsutsui, Neil D

    2016-04-01

    Parasitoids often use complex cues to identify suitable hosts in their environment. Phorid fly parasitoids that develop on one or a few host species often use multiple cues, ranging from general to highly specific, to home in on an appropriate host. Here, we describe the hierarchy of cues that Pseudacteon phorid flies use to identify Azteca ant hosts. We show, through behavioral observations in the field, that phorid flies are attracted to two cryptic Azteca species, but only attack Azteca sericeasur (Hymenoptera: Formicidae: Dolichoderinae). To test whether the phorid flies use cuticular hydrocarbons (CHCs) to distinguish between the two Azteca taxa, we first documented and compared cuticular hydrocarbons of the two Azteca taxa using gas chromatography/mass spectrometry. Then, using cuticular hydrocarbon-transfer experiments with live ants, we characterized the cuticular hydrocarbons of A. sericeasur as a short-range, host location cue used by P. lasciniosus (Diptera: Phoridae) to locate the ants. PMID:27130489

  13. Implanted electrode recordings from a praying mantis auditory interneuron during flying bat attacks.

    PubMed

    Triblehorn, Jeffrey D; Yager, David D

    2002-02-01

    Using an implanted electrode, we recorded the responses from the ultrasound-sensitive mantis interneuron 501-T3 during flying bat attacks in a large flight room where the mantis served as the target. 501-T3 responds to each vocalization emitted with multi-spike bursts when pulse repetition rates (PRRs) are below 55 pulses x s(-1). As PRR increases and pulse durations fall below 3 ms, 501-T3 ceases burst activity. On average, spike bursts cease 272 ms before contact (when the bat is 73 cm away from the preparation). The timing of cessation of activity in 501-T3 is similar to the latency for the diving portion of the response of the mantid (242 ms). Experiments using vocalizing stationary bats confirm that 501-T3 responds more reliably to longer pulse durations (> or =3 ms) when intensities are below 90 dB pe SPL. The cessation of 501-T3 activity is probably due both to the increasing PRR and to the decreasing pulse duration that occur in the terminal buzz phase of a bat attack. 501-T3 may be actively shut off at high PRRs and/or intensities to protect the interneuron from habituation while the mantis performs an escape response. The cessation of 501-T3 activity is consistent with the lack of a very late ultrasound-mediated evasive response by the mantis. However, cessation of 501-T3 activity may allow a true 'last-chance' response to be mediated by other neural systems. PMID:11854368

  14. Resistance of class C fly ash belite cement to simulated sodium sulphate radioactive liquid waste attack.

    PubMed

    Guerrero, A; Goñi, S; Allegro, V R

    2009-01-30

    The resistance of class C fly ash belite cement (FABC-2-W) to concentrated sodium sulphate salts associated with low level wastes (LLW) and medium level wastes (MLW) is discussed. This study was carried out according to the Koch and Steinegger methodology by testing the flexural strength of mortars immersed in simulated radioactive liquid waste rich in sulphate (48,000 ppm) and demineralised water (used as a reference), at 20 degrees C and 40 degrees C over a period of 180 days. The reaction mechanisms of sulphate ion with the mortar was carried out through a microstructure study, which included the use of Scanning electron microscopy (SEM), porosity and pore-size distribution and X-ray diffraction (XRD). The results showed that the FABC mortar was stable against simulated sulphate radioactive liquid waste (SSRLW) attack at the two chosen temperatures. The enhancement of mechanical properties was a result of the formation of non-expansive ettringite inside the pores and an alkaline activation of the hydraulic activity of cement promoted by the ingress of sulphate. Accordingly, the microstructure was strongly refined. PMID:18524482

  15. Pseudacteon calderensis, a new fly species (Diptera:Phoridae) attacking the fire ant Solenopsis interrupta (Hymenoptera:Formicidae) in northwestern Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of Pseudacteon phorid fly Pseudacteon calderis (Diptera: Phoridae) is described from females attacking worker ants of Solenopsis interrupta Santschi in Salta and Jujuy provinces, northwestern Argentina. Pseudacteon calderis differs from almost all other South American Pseudacteon speci...

  16. Generation of VLF saucer emissions observed by the Viking satellite

    SciTech Connect

    Loennqvist, H.; Andre, M.; Matson, L.; Bahnsen, A.; Blomberg, L.G.; Erlandson, R.E.

    1993-08-01

    The authors report observations of V shaped saucer emissions by the Viking satellite. This V shaped saucer emission refers to the observational feature of the VLF or ELF emissions which shows a v shaped appearance on a plot of frequency as a function of time. Viking provided not only wave, but electric and magnetic field measurements, as well as charged particle measurements. These measurements show electrons flowing upwards with enegies of up to a few hundred eV in conjunction with the saucer emissions. Other wave structures observed in this same region may originate from the electron flows. The satellite observations also find such events at altitudes from 4000 to 13000km, where the generation region is found to be much more spread out in space.

  17. Exploratory trial to determine the efficacy of the PYthon and the PYthon Magnum slow-release insecticide ear tags for the control of midges (Culicoides spp.), attacking sheep and cattle and flies attacking cattle.

    PubMed

    Goosen, H; de Vries, P J T; Fletcher, M G

    2012-08-01

    This study investigated the prophylactic action of the chemical combination zeta-cypermethrin and piperonyl butoxide, administered by means of slow-release insecticide-impregnated ear tags, against biting midges (Culicoides spp) attacking sheep and against midges, horn flies (Haematobia irritant), stable flies (Stomoxys calcitrans), and houseflies (Musca domestica) attacking cattle. Treated sheep and cattle were protected 100 percent against blood-feeding midges for two months and there was a clear reduction in the number of midges collected from treated animals. Three days after the ear tags were attached to cattle, the number of horn flies on the cattle was reduced to practically zero and remained at a low level until the end of the trial (day 85). There was also a strong reduction in the numbers of stable flies and houseflies counted. PMID:22930983

  18. Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

    NASA Astrophysics Data System (ADS)

    Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

    2016-02-01

    Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

  19. Attacks on the endangered Attwater's Prairie-Chicken (Tympanuchus cupido attwateri) by black flies (Diptera: Simuliidae)infected with an avian blood parasite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With fewer than 50 birds remaining in the wild, Attwater's Prairie-Chicken (Tympanuchus cupido attwateri) is critically endangered. Individuals of the Attwater Prairie-Chicken have been attacked in successive winters, 2005-2006, by the black fly Cnephia ornithophilia. Attwater's Prairie-Chicken is a...

  20. Risk-spreading larviposition behaviour of female nose bot flies (Cephenemyia) attacking black-tailed deer.

    PubMed

    Anderson, J R

    2013-06-01

    While baited deer models were under observation nine Cephenemyia jellisoni Townsend (Diptera: Oestridae) females and seven C. apicata Bennett & Sabrosky engaged in a risk-spreading larviposition behaviour by larvipositing on models only once and then flying away. Additionally, analysis of 225 unobserved larvipostions in which larvae were trapped in adhesive on the muzzles of deer models showed that 94% of C. apicata and 95% of C. jellisoni larviposited on a model only once. The number of single larvipositions was highly significant for both species. The principal adaptive significance of such risk-spreading larviposition behaviour is that it spreads the reproductive output of a female among many hosts, and in years when adult eclosion and survival rates are low, it ensures that the larvae of the few surviving females will be distributed among a maximum number of hosts. Several other benefits of such behaviour also are discussed. PMID:22971133

  1. FLIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flies constitute a major group of nuisance species world wide in rural and urban situations. The public and health care officials can become more aware of the potential risks from flies and other urban pests by compiling the available information into an easily readable book form. Scientists from ...

  2. Investigations into Outbreaks of Black Fly Attacks and Subsequent Avian Haemosporidians in Backyard-Type Poultry and Other Exposed Avian Species.

    PubMed

    Jones, Kelli; Johnson, Nora; Yang, Sharon; Stokes, John; Smith, Whitney; Wills, Robert; Goddard, Jerome; Varela-Stokes, Andrea

    2015-03-01

    In late spring of 2009 and 2010, there were reports of severe black fly (Simulium spp., shown in Fig. 1) outbreaks in various counties in Mississippi, especially those in and around the Mississippi River Delta. Complaints were of black flies attacking multiple species of backyard poultry and causing high morbidity and mortality in affected flocks. At several affected locations, black flies were readily observed swarming around and feeding on birds. A large number of these parasites were easily trapped on fly strips (Fig. 2). Multifocal to coalescing cutaneous hemorrhagic lesions, consistent with fly bites, were seen on the birds. Upon necropsy examination, a large number of black flies were also observed in the digestive tract (Fig. 3). Although black flies may cause disease directly, such as cardiopulmonary collapse and anaphylactoid reactions, detection of Leucocytozoon in blood smears (Fig. 4) of affected birds prompted further investigations of this protozoan as a cause of disease. Leucocytozoon spp. are known to be transmitted by black flies and may be associated with morbidity and mortality in birds such as poultry. From June 2009 through July 2012, the investigation included a total collection of 1068 individual blood samples, representing 371 individual premises in 89 counties/parishes across Mississippi (59), Alabama (10), Louisiana (4), and Tennessee (16). Of the 371 premises where blood samples were collected, 96 (26%) were either positive or highly suspected to be positive for Leucocytozoon spp. by blood smear analysis, and 5 (1.2%) were positive for Haemoproteus spp. by blood smear analysis. Attempts to diagnose Leucocytozoon spp. by PCR analysis and sequencing were complicated by coinfections with two closely related haemosporidians (Haemoproteus spp. and Plasmodium spp.). A novel technique involving flow cytometry was also explored. This study discusses the black fly field outbreak, the involvement of haemosporidians, molecular methods for detection

  3. Modeling Mechanisms of Saucer-Shaped Sill Formation

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Bunger, A.

    2006-12-01

    Magmatic sills have a basic tendency to form concave-upward saucer shapes. This morphology is observed in numerous seismic images and in the striking formations which dominate the landscape in South Africa's Karoo Basin. The propensity of sills to curve upward has also been suggested as a mechanism for magma ascent, particularly in compressive tectonic regions. Recent efforts that are focused on understanding the fundamental mechanisms controlling the saucer curvature indicate that saucer-shaped growth should be understood to result from asymmetry in the induced stress field near the fracture tip that results when the sill attains a size similar to its depth. Here we explore this phenomenon numerically and extend the consideration to examine the tendency of sills that are growing in a naturally layered environment to curve upward as they mechanically interact with a stiffer underlying layer or softer overlying layer. Our numerical model is based on the displacement discontinuity method, where the presence of three layers is accounted for explicitly in the plane strain linear elastic fundamental solution upon which the method is built. The equations governing fluid flow in the fracture are solved using a finite difference method, but here we consider only the limiting case where the effects of viscous dissipation are shown to be negligible so that the internal fluid pressure is uniform. The numerical results are first compared with laboratory experiments performed by injecting glycerin or glucose- based fluids to form hydraulic fractures in PMMA or glass specimens. The particular case of a fracture growing near a free-surface is examined. Reasonable agreement for the curving fracture path is found between the numerical model and experimental results up until the point where the initial radial symmetry in the experiments breaks down and the fracture elongates to become egg-shaped in plan view as growth favors one direction over the others. The numerical model is then

  4. Saucer-Shaped Sandstone Intrusions: Facts, Inferences and Unknowns

    NASA Astrophysics Data System (ADS)

    Huuse, M.; Cartwright, J. A.

    2007-12-01

    Saucer-shaped and conical sandstone intrusions occur in abundance within Paleogene claystones of the North Sea Basin and within Paleogene-Neogene claystones of the Faroe-Shetland and More Basins along the NW European Atlantic Margin. The dimensions of individual saucers range from 50-300m height, 0.5-2 km width, and 0.5-4 km length, with sandstone volumes up to some 0.5 cubic kilometres. Clusters of saucers may contain composite intruded volumes up to several cubic kilometres and may form significant reservoir bodies for hydrocarbon accumulations. Conical sandstone intrusions have similar dimensions, though their width, length and volumes are limited by their downward tapering geometry with a central pointy apex, lacking a horizontal segment in the centre. Whilst their occurrence, dimensions and significance within their known host basins are no longer in doubt, virtually all the parameters relating to their genesis are poorly constrained and either inferred or declared unknown in the existing literature. These include: source of the intruded sand, timing of intrusion (both duration and age), depth of emplacement, triggering mechanism(s), relation with underlying structures and/or structures within and the rheology of the host claystones, etc. It is also largely unknown whether intrusions occurred largely synchronously or during a multitude of events within their host basins. Without a rigorous analysis of which parameters are known and which are inferred or essentially unknown, any analysis of the origin of sandstone intrusions remains speculation and may be highly misleading. This paper presents examples and highlights the facts, inferences and unknowns for each of the case studies drawn from the northern North Sea and the Faroe-Shetland Basin and summarises the implications of these uncertainties for the analysis of the origin of the intrusions.

  5. Effect of the Drosophila endosymbiont Spiroplasma on parasitoid wasp development and on the reproductive fitness of wasp-attacked fly survivors.

    PubMed

    Xie, Jialei; Tiner, Bethany; Vilchez, Igor; Mateos, Mariana

    2011-09-01

    In a previous study, we showed that Spiroplasma, a maternally transmitted endosymbiotic bacterium of Drosophila hydei, enhances larval to adult survival of its host when exposed to oviposition attack by the parasitoid wasp Leptopilina heterotoma. The mechanism by which Spiroplasma enhances host survival has not been elucidated. To better understand this mechanism, we compared the growth of wasp larvae in Spiroplasma-infected and uninfected hosts. Our results indicate that wasp embryos in Spiroplasma-infected hosts hatch and grow normally for ~2 days, after which their growth is severely impaired, compared to wasps developing in uninfected hosts. Thus, despite their reduced ability to complete development in Spiroplasma-infected hosts, developing wasps may exert fitness costs on their hosts that are manifested after host emergence. The severity of these costs will influence the degree to which this protective mechanism contributes to the long-term persistence of Spiroplasma in D. hydei. We therefore examined survival to 10-day-old adult stage and fecundity of Spiroplasma-infected flies surviving a wasp treatment. Our results suggest detrimental effects of wasp attack on longevity of Spiroplasma-infected adult flies. However, compared to Spiroplasma-free flies exposed to wasps, Spiroplasma-infected flies exposed to wasps have ~5 times greater survival from larva to 10 day-adult. The relative fecundity of wasp-attacked Spiroplasma-infected females was ~71% that of un-attacked Spiroplasma-free females. Our combined survival and female fecundity results suggest that under high wasp parasitism, the reproductive fitness of Spiroplasma-infected flies may be ~3.5 times greater than that of uninfected females, so it is potentially relevant to the persistence of Spiroplasma in natural populations of D. hydei. Interestingly, Spiroplasma-infected males surviving a wasp attack were effectively sterile during the 3-day period examined. This observation is consistent with the

  6. Arthroscopic Saucerization and Repair of Discoid Lateral Meniscal Tear.

    PubMed

    Fields, Logan K; Caldwell, Paul E

    2015-04-01

    Meniscal tears are among the most commonly diagnosed knee injuries and often require surgical intervention. Understanding the types of meniscal tears and treatment options is paramount to caring for the young athlete. Sports medicine and arthroscopic physicians now recognize that meniscal preservation in the young athlete is essential to the long-term health and function of the knee. Although uncommon, the discoid lateral meniscus is more prone to injury because of its increased thickness and lack of blood supply. Because of the abnormal development, the peripheral attachments are frequently absent and instability often persists after a partial meniscectomy. If the instability is unrecognized during the initial treatment, a recurrence of pain and mechanical symptoms is likely and a subsequent subtotal meniscectomy may be the only treatment option. With increased awareness, arthroscopic saucerization accompanied by arthroscopically assisted inside-out meniscal repair is a preferable treatment option with an excellent outcome. PMID:26052498

  7. Arthroscopic Saucerization and Repair of Discoid Lateral Meniscal Tear

    PubMed Central

    Fields, Logan K.; Caldwell, Paul E.

    2015-01-01

    Meniscal tears are among the most commonly diagnosed knee injuries and often require surgical intervention. Understanding the types of meniscal tears and treatment options is paramount to caring for the young athlete. Sports medicine and arthroscopic physicians now recognize that meniscal preservation in the young athlete is essential to the long-term health and function of the knee. Although uncommon, the discoid lateral meniscus is more prone to injury because of its increased thickness and lack of blood supply. Because of the abnormal development, the peripheral attachments are frequently absent and instability often persists after a partial meniscectomy. If the instability is unrecognized during the initial treatment, a recurrence of pain and mechanical symptoms is likely and a subsequent subtotal meniscectomy may be the only treatment option. With increased awareness, arthroscopic saucerization accompanied by arthroscopically assisted inside-out meniscal repair is a preferable treatment option with an excellent outcome. PMID:26052498

  8. Effectiveness of a sprayable male annihilation treatment with a biopesticide against fruit flies (Diptera:Tephritidae) attacking tropical fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SPLAT-MAT Spinosad ME(aka STATIC Spinosad ME),an "attract and kill" sprayable biopesticide, was evaluated as an area wide suppression treatment against Bactrocera carambolae(Drew & Hancock),carambola fruit fly, in Brazil and Bactrocera dorsalis(Hendel),oriental fruit fly, in Hawaii. In Brazil, a sin...

  9. Saucer-shaped Clastic Intrusions and Associated Injectites in the Westerm San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Hurst, A.; Vigorito, M.; Vetel, W.; Cartwright, J.

    2007-12-01

    Clastic sills, including saucer-shaped intrusions, are the most volumetrically significant clastic intrusions in the Panoche Giant Injectite Complex (PGIC). Injection occurred in the Lower Paleocene during a period of inversion caused by the convergence of the Pacific and North American plates. Almost 400 km2 of exposure reveals the relationships between clastic intrusions, their parent beds and seafloor sand extrusions (extrudites). Sand was injected into partially-consolidated deepwater mudstones of late Cretaceous and early Paleocene age in a single event but with many pulses that produced cross-cutting intrusions. More than 40 km3 of sand is estimated to have injected within the area of outcrop. The total thickness of strata cut by injections (from deepest known Lower Cretaceous parent bed to extrudite) is in excess of 1.2 km. Saucer-shaped intrusions are composite features that comprise sills, low-angle dikes and dike swarms, arranged as low-angle conical or saucer-shaped injected units that exhibit a semi-elliptical to horse-shoe geometry in plan view and are V- or U-shaped in cross section. Saucer-shaped intrusions are 500 to 1.5km wide and in some cases cut through more than 250 m of stratigraphic section. The lowest parts of the saucer-shaped intrusions consists of multiply-stacked, low-angle dikes up to 80m thick that cut the stratigraphy at angles between 5-10º and locally exhibit stepped or transgressive geometry. The low-angle dykes are 8 to 20 m wide and laterally continuous over distances of a few to several hundreds of metres. Steeper segments (up to 30 deg) emanate laterally from the periphery of the lowest units and cut through the host-rock for a few up to several tens of metres, pinching-out laterally over distances of several tens to a few hundreds of metres. At their margins the saucer-shaped intrusions are bounded by steep (50-70 deg), narrow dikes (generally <1 m wide); such dikes are unlikely to be imaged on seismic data. The central areas

  10. Differential Responses of Wheat Inhibitor-Like Genes to Hessian Fly (Mayetiola destructor) Attacks during Compatible and Incompatible Interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four groups of inhibitor-like genes encoding proteins with diverse structures were identified from wheat. The majority of these genes were up-regulated by avirulent Hessian fly (Mayetiola destructor) larvae during incompatible interactions, and were down-regulated by virulent larvae during compatib...

  11. The 3D geometry of regional-scale dolerite saucer complexes and their feeders in the Secunda Complex, Karoo Basin

    NASA Astrophysics Data System (ADS)

    Coetzee, André; Kisters, Alexander

    2016-05-01

    Dolerites in the Karoo Basin of South Africa commonly represent kilometre-scale, interconnected saucer-shaped structures that consist of inner sills, bounded by inclined sheets connected to stratigraphically higher outer sills. Based on information from over 3000 boreholes and mining operations extending over an area of ca. 500 km2 and covering a > 3 km vertical section from Karoo strata into underlying basement rocks, this paper presents the results of a 3D modelling exercise that describes the geometry and spatial relationships of a regional-scale saucer complex, locally referred to as the number 8 sill, from the Secunda (coal mine) Complex in the northern parts of the Karoo Basin. The composite number 8 sill complex consists of three main dolerite saucers (dolerites A to C). These dolerite saucers are hosted by the Karoo Supergroup and the connectivity and geometry of the saucers support a lateral, sill-feeding-sill relationship between dolerite saucers A, B and C. The saucers are underlain and fed by a shallowly-dipping sheet (dolerite D) in the basement rocks below the Karoo sequence. The 3D geometric strata model agrees well with experimental results of saucer formation from underlying feeders in sedimentary basins, but demonstrates a more intricate relationship where a single feeder can give rise to several split level saucers in one regionally extensive saucer complex. More localised dome- or ridge-shape protrusions are common in the flat lying sill parts of the regional-scale saucers. We suggest a mode of emplacement for these kilometre-scale dome- and ridge structures having formed as a result of lobate magma flow processes. Magma lobes, propagating in different directions ahead of the main magma sheet, undergo successive episodes of lobe arrest and inflation. The inflation of lobes initiates failure of the overlying strata and the formation of curved faults. Magma exploiting these faults transgresses the stratigraphy and coalesces to form a ring

  12. Mechanisms Of Saucer-Shaped Sill Emplacement: Insight From Experimental Modeling

    NASA Astrophysics Data System (ADS)

    Galland, O.; Planke, S.; Malthe-Sørenssen, A.; Polteau, S.; Svensen, H.; Podladchikov, Y. Y.

    2006-12-01

    It has been recently demonstrated that magma intrusions in sedimentary basins had a strong impact on petroleum systems. Most of these intrusions are sills, and especially saucer-shaped sills. These features can be observed in many sedimentary basins (i.e. the Karoo basin, South Africa; the Norwegian and North Sea; the Tunguska basin, Siberia; the Neuquén basin in Argentina). The occurrence of such features in so various settings suggests that their emplacement results from fundamental processes. However, the mechanisms that govern their formation remain poorly constrained. Experiments were conducted to simulate the emplacement of saucer-shaped magma intrusions in sedimentary basins. The model rock and magma were fine-grained silica flour and molten vegetable oil, respectively. This modeling technique allows simultaneous simulation of magma emplacement and brittle deformation at a basin scale. For our purpose, we performed our experiments without external deformation. During the experiments, the oil was injected horizontally at constant flow rate within the silica flour. Then the oil initially emplaced in a sill, whereas the surface of the model inflated into a smooth dome. Subsequently, the oil propagated upwards along inclined sheets, finally reaching the surface at the edge of the dome. The resulting geometries of the intrusions were saucer-shaped sills. Then the oil solidified, and the model was cut in serial cross-sections through which the structures of the intrusive body and of the overburden can be observed. In order to constraint the processes governing the emplacement of such features, we performed a parametric study based on a set of experiments in which we systematically varied parameters such as the depth of emplacement and the injection flow rate of the oil. Our results showed that saucer diameters are larger at deeper level of emplacement. Opposite trend was obtained with varying injection flow rates. Based on our results, we conducted a detailed

  13. Magnetic fabric of saucer-shaped sills in the Karoo Large Igneous Province

    NASA Astrophysics Data System (ADS)

    Polteau, S.; Ferre, E. C.; Planke, S.; Neumann, E.; Chevallier, L.

    2007-12-01

    Magmatic sill intrusions commonly exhibit a saucer geometry in undeformed sedimentary basins and volcanic rifted margins. Current emplacement models are based on the analysis of the intrusion geometry and their spatial relationships with potential feeders, not on the knowledge of the magma flow geometry. The Karoo Basin of South Africa hosts hundreds of saucer-shaped sills. Amongst these, the Golden Valley Sill is well-exposed and displays the connections with adjacent and nested saucers. A combination of detailed fieldwork observations and the anisotropy of magnetic susceptibility measurements were used to identify strain markers that can be interpreted in terms of magma flow directions. A total of 113 localities (6 specimens/site), mostly including opposite sill margins, have been sampled for anisotropy of magnetic susceptibility (AMS) analyses. The magnetic properties were defined by measuring hysteresis cycles and K-T curves on 34 and 19 specimens, respectively. The majority of the localities display well-defined magnetic foliations that consistently dip outward from the centre of the Golden Valley Sill. This orientation of the magnetic foliation most likely represents inflation/deflation cycles of the intruding sill that interacts with non-static enclosing walls. In addition, four magma channels were identified and display an imbrication of the magnetic foliation that indicates an outward magma flow direction. In conclusion, the observed magma flow geometries derived from macroscopic flow indicators and the AMS data correlate well and are used to constrain an emplacement model for the Golden Valley Sill Complex. Finally, the emplacement model of sill complexes repeats the cycle -injection of magma - formation of a saucer-shaped sill - pressure build up - fracturation and pressure drop - channeling of magma - injection of (new batch of) magma - formation of a new saucer-shaped sill- until the magma supply stops.

  14. Dykes, cups, saucers and sills: Analogue experiments on magma intrusion into brittle rocks

    NASA Astrophysics Data System (ADS)

    Mathieu, L.; van Wyk de Vries, B.; Holohan, Eoghan P.; Troll, Valentin R.

    2008-07-01

    Magma is transported in the crust by blade-like intrusions such as dykes, sills, saucers, and also collects in thicker laccoliths, lopoliths and plutons. Recently, the importance and great number of shallow (< 5 km) saucer-shaped intrusions has been recognized. Lopoliths and cup-shaped intrusions have also been reported in many geological contexts. Our field observations indicate that many intrusions, especially those emplaced into breccias or fractured rocks, have bulging, lobate margins and have shear faults at their bulbous terminations. Such features suggest that magma can propagate along a self-induced shear fault rather than a hydraulic tension-fracture. To investigate this we use analogue models to explore intrusion propagation in a brittle country rock. The models consist of the injection of analogue magma (honey or Golden syrup) in a granular material (sand or sieved ignimbrite) that is a good analogue for brittle or brecciated rocks. These models have the advantage (over other models that use gelatin) to well represent the properties of brittle materials by allowing both shear-faults and tension fractures to be produced at suitable stresses. In our experiments we mainly obtain vertical dykes and inverted-cone like structures that we call cup-shaped intrusions. Dykes bifurcate into cup-shaped intrusions at depths depending on their viscosity. All cup-shaped intrusions uplift a central block. By injecting against a vertical glass plate we obtain detailed observations of the intrusion propagation style. We observe that dykes commonly split and produce cup-shaped intrusions near the surface and that shear zone-related intrusions develop at the dyke tip. We conclude that many dykes propagate as a viscous indenter resulting from shear failure of host rock rather than tensional hydraulic fracturing of host rocks. The shear propagation model provides an explanation for the shape and formation of cup-shaped intrusions, saucer-sills and lopoliths.

  15. Heart attack

    MedlinePlus

    ... infarction; Non-ST-elevation myocardial infarction; NSTEMI; CAD-heart attack; Coronary artery disease-heart attack ... made up of cholesterol and other cells. A heart attack may occur when: A tear in the ...

  16. Cretaceous Magmatic Episodes and Saucer-Shaped Sills in the Sverdrup Basin, Canadian Arctic Islands

    NASA Astrophysics Data System (ADS)

    Evenchick, C. A.; Davis, B.; Hayward, N.

    2013-12-01

    Understanding the nature and age of Cretaceous magmatic rocks in the Sverdrup Basin is central to refined interpretations of opening of the Amerasia Basin. The Sverdrup Basin is a Carboniferous to latest Cretaceous marine and nonmarine basin that underlies the northern Canadian Arctic Islands. It is bordered by deformed lower Paleozoic rocks to the south and the Canadian portion of the Amerasia Basin margin to the north. Cretaceous igneous rocks in the Sverdrup Basin include volcanic rocks, volcanogenic sedimentary rocks, dykes, and sills. A significant challenge for using magmatic events to understand tectonic history is the problem of obtaining sufficient ages of magmatism that are representative and well-constrained. In this paper we use the relationship between the size of saucer-shaped sills and their depth of emplacement to interpret ages of magmatism on Ellef Ringnes Island, near the centre of the Sverdrup Basin. New analyses of intrusive and extrusive rocks include: field work, high precision geochronology, map compilation, integration with potential field data, and analysis of a group of intrusions considered to be saucer-shaped sills. Recognition of the saucer-shaped geometry of the sills permits interpretation of their depth of emplacement, which, combined with a well constrained stratigraphic column, allows indirect interpretation of their age of emplacement. A U-Pb baddelyite date on one of the sills is consistent with a lower Aptian age of emplacement as determined by the depth of emplacement method for one of the sill clusters. Based on this analysis the sills were intruded in at least 4 episodes, many of the sills were coeval with deposition of the upper Isachsen Formation, and three episodes were coeval with lower Isachsen, mid-Christopher and lower Hassel formation volcanogenic deposits in the study area. Volcanism in the Queen Elizabeth Islands was spatially greater than previously recognized, and intrusive activity was longer-lived and in

  17. Multi-state survey of picture-winged flies (Diptera:Ulidiidae) attacking sweet corn in the southern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four picture-winged fly (Diptera: Ulidiidae) species in two genera were identified as direct pests of sweet and field corn ears in Florida from surveys conducted during 2007 and 2008. Larvae emerge from eggs deposited mostly in the silk canal to damage silk, kernels and cob rendering infested sweet...

  18. Pelocoris balius La Rivers (Hemiptera: Heteroptera: Naucoridae) in Florida: New Status of an Enigmatic Saucer Bug.

    PubMed

    Sites, Robert W

    2015-01-01

    The saucer bug subspecies Pelocoris femoratus balius La Rivers was described from east-central Florida and differs from the nominate subspecies by pronounced dark spotting on the fore femora, head, and pronotum. This subspecies is much less commonly encountered than is P. f. femoratus (Palisot de Beauvois), which occurs throughout Florida. Although both subspecies occur in the area, uncertainty about the taxonomic status of P. f. balius has persisted. I here elevate P. f. balius to full species status based on collections of both taxa from the same bodies of water in multiple counties and additional morphological differences to those given in the original description. A supplemental description, distribution map, and illustrations to distinguish between the two species are provided.  PMID:25662135

  19. Successful Utilization of the Area-Wide Approach for Management of Fruit Flies in Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Melon fly, Bactrocera cucurbitae (Coquillett), Mediterranean fruit fly, Ceratitis capitata (Wiedemann), oriental fruit fly, Bactrocera dorsalis (Hendel), and the so-called Malaysian (solenaceous) fruit fly, Bactrocera latifrons (Hendel), have accidentally become established in Hawaii, and attack mor...

  20. Vertical linear feeder to elliptical igneous saucer-shaped sills: evidences from structural observations, geochemistry and experimental modeling

    NASA Astrophysics Data System (ADS)

    Galerne, C. Y.; Galland, O.; Neumann, E. R.; Planke, S.

    2009-12-01

    The structural relationships between sills and their feeders are poorly documented because they are rarely observed in the field and difficult to image on seismic data. For instance, it is unclear whether sills are fed by pipes, dikes or other sills. Nevertheless, the geometrical relationships between sills and their feeders provide first-order constraints on magma emplacement mechanisms. Here, we investigate the structural and geochemical relationships between sills and potential feeder dikes in a remarkably well-preserved and exposed sill complex, the Golden Valley Sill Complex (GVSC), Karoo Basin, South Africa. The GVSC consists of five major saucer-shaped sills and six dikes. The Golden Valley sill itself is an elliptical saucer, with a N-S trend. A one meter thick dike (D4) crops out underneath the southern tip of the Golden Valley sill. The strike of this dike is parallel to the long axis of the Golden Valley sill. Detailed sampling and geochemical analyses of the GVSC show that each sill and dike exhibits a specific geochemical signature. The Golden Valley sill and its underlying dike D4 have identical signatures. Although there is no clear structural evidence, the consistent geometrical and geochemical relationships between the Golden Valley sill and the D4 dike suggest that this vertical linear structure is the feeder of the overlying saucer-shaped sill. In order to investigate the relationships between sills and feeders, we resorted to scaled laboratory experiments. The experiments consisted of a low-viscosity vegetable oil representing magma and a cohesive fine-grained silica flour representing brittle rocks. We placed a horizontal weak layer into the silica flour, just above the top of the inlet, to simulate strata. Such a weak layer controlled the formation of horizontal sill that subsequently turned into a transgressive sheet leading to the formation of a saucer geometry. We ran experiments with varying inlet shapes: 1) a point inlet representing a

  1. Heart Attack

    MedlinePlus

    ... attack treatment works best when it's given right after symptoms occur. Prompt treatment of a heart attack can help prevent or limit damage to the heart and prevent sudden death. Call 9-1-1 Right Away A heart ...

  2. Heart attack

    MedlinePlus

    ... a heart attack take part in a cardiac rehabilitation program. ... al. eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, PA: Elsevier Saunders; 2014: ...

  3. Strong Magnetic Field Fluctuations within Filamentary Auroral Density Cavities Interpreted as VLF Saucer Sources

    NASA Technical Reports Server (NTRS)

    Knudsen, D. L.; Kabirzadeh, R.; Burchill, J. K.; Pfaff, Robert F.; Wallis, D. D.; Bounds, S. R.; Clemmons, J. H.; Pincon, J.-L.

    2012-01-01

    The Geoelectrodynamics and Electro-Optical Detection of Electron and SuprathermalIon Currents (GEODESIC) sounding rocket encountered more than 100 filamentary densitycavities associated with enhanced plasma waves at ELF (3 kHz) and VLF (310 kHz)frequencies and at altitudes of 800990 km during an auroral substorm. These cavities weresimilar in size (20 m diameter in most cases) to so-called lower-hybrid cavities (LHCs)observed by previous sounding rockets and satellites; however, in contrast, many of theGEODESIC cavities exhibited up to tenfold enhancements in magnetic wave powerthroughout the VLF band. GEODESIC also observed enhancements of ELF and VLFelectric fields both parallel and perpendicular to the geomagnetic field B0 within cavities,though the VLF E field increases were often not as large proportionally as seen in themagnetic fields. This behavior is opposite to that predicted by previously published theoriesof LHCs based on passive scattering of externally incident auroral hiss. We argue thatthe GEODESIC cavities are active wave generation sites capable of radiating VLF wavesinto the surrounding plasma and producing VLF saucers, with energy supplied by cold,upward flowing electron beams composing the auroral return current. This interpretation issupported by the observation that the most intense waves, both inside and outside cavities,occurred in regions where energetic electron precipitation was largely inhibited orabsent altogether. We suggest that the wave-enhanced cavities encountered by GEODESICwere qualitatively different from those observed by earlier spacecraft because of thefortuitous timing of the GEODESIC launch, which placed the payload at apogee within asubstorm-related return current during its most intense phase, lasting only a few minutes.

  4. Strong magnetic field fluctuations within filamentary auroral density cavities interpreted as VLF saucer sources

    NASA Astrophysics Data System (ADS)

    Knudsen, D. J.; Kabirzadeh, R.; Burchill, J. K.; Pfaff, R. F.; Wallis, D. D.; Bounds, S. R.; Clemmons, J. H.; Pinçon, J.-L.

    2012-02-01

    The Geoelectrodynamics and Electro-Optical Detection of Electron and Suprathermal Ion Currents (GEODESIC) sounding rocket encountered more than 100 filamentary density cavities associated with enhanced plasma waves at ELF (<3 kHz) and VLF (3-10 kHz) frequencies and at altitudes of 800-990 km during an auroral substorm. These cavities were similar in size (˜20 m diameter in most cases) to so-called lower-hybrid cavities (LHCs) observed by previous sounding rockets and satellites; however, in contrast, many of the GEODESIC cavities exhibited up to tenfold enhancements in magnetic wave power throughout the VLF band. GEODESIC also observed enhancements of ELF and VLF electric fields both parallel and perpendicular to the geomagnetic field B0 within cavities, though the VLF E field increases were often not as large proportionally as seen in the magnetic fields. This behavior is opposite to that predicted by previously published theories of LHCs based on passive scattering of externally incident auroral hiss. We argue that the GEODESIC cavities are active wave generation sites capable of radiating VLF waves into the surrounding plasma and producing VLF saucers, with energy supplied by cold, upward flowing electron beams composing the auroral return current. This interpretation is supported by the observation that the most intense waves, both inside and outside cavities, occurred in regions where energetic electron precipitation was largely inhibited or absent altogether. We suggest that the wave-enhanced cavities encountered by GEODESIC were qualitatively different from those observed by earlier spacecraft because of the fortuitous timing of the GEODESIC launch, which placed the payload at apogee within a substorm-related return current during its most intense phase, lasting only a few minutes.

  5. Heart Attack

    MedlinePlus

    ... a million people in the U.S. have a heart attack. About half of them die. Many people have permanent heart damage or die because they don't get ... It's important to know the symptoms of a heart attack and call 9-1-1 if someone ...

  6. Pollen recovered from the exoskeleton of stable flies, Stomoxys calcitrans (L.) in Gainesville, Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stable flies are pestiferous blood feeding flies that attack animals and humans. Besides consuming blood, these flies will also visit flowers to take nectar meals. When feeding on nectar, flies become coated with pollen which can be used to identify flowers used by the flies. Recently, flies cove...

  7. A novel adipokinetic peptide in a water boatman (Heteroptera, Corixidae) and its bioanalogue in a saucer bug (Heteroptera, Naucoridae).

    PubMed

    Gäde, Gerd; Simek, Petr; Marco, Heather G

    2007-03-01

    The corpora cardiaca (CC) of two water bug species, the water boatman Corixa punctata and the saucer bug Ilyocoris cimicoides, contain a substance that cause hyperlipemia in the migratory locust. The primary sequence of one octapeptide belonging to the adipokinetic hormone (AKH)/red pigment-concentrating hormone (RPCH) family was deduced from the multiple MS(N) electrospray mass data of CC material from each species. Whereas the saucer bug contains the known octapeptide pGlu-Val-Asn-Phe-Ser-Pro-Ser-Trp amide, code-named Anaim-AKH, the water boatman has a novel peptide identified as pGlu-Leu/Ile-Asn-Phe-Ser-Pro-Ser-Trp amide, code-named Corpu-AKH. The ambiguity about the amino acid at position 2, i.e. Leu or Ile, in Corpu-AKH was solved by isolating the peptide in a single-step by reversed-phase HPLC and establishing co-elution with the synthetic peptide containing Leu at position 2. Functionally, the peptides regulate lipid mobilization, as evidenced by an adipokinetic effect after injecting synthetic Anaim-AKH and Corpu-AKH into the respective acceptor species. Swimming activity of I. cimicoides also causes hyperlipemia. PMID:17215060

  8. Heart Attack

    MedlinePlus

    ... lower “bad” cholesterol (also called LDL, or low-density lipoprotein) levels and may help increase “good” cholesterol (also called HDL, or high-density lipoprotein). If you have had a heart attack, ...

  9. Heart Attack

    MedlinePlus

    ... have a heart attack. About half of them die. Many people have permanent heart damage or die because they don't get help immediately. It's ... few hours causes the affected heart muscle to die. NIH: National Heart, Lung, and Blood Institute

  10. Flying wings / flying fuselages

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Bauer, Steven X. S.

    2001-01-01

    The present paper has documented the historical relationships between various classes of all lifting vehicles, which includes the flying wing, all wing, tailless, lifting body, and lifting fuselage. The diversity in vehicle focus was to ensure that all vehicle types that map have contributed to or been influenced by the development of the classical flying wing concept was investigated. The paper has provided context and perspective for present and future aircraft design studies that may employ the all lifting vehicle concept. The paper also demonstrated the benefit of developing an understanding of the past in order to obtain the required knowledge to create future concepts with significantly improved aerodynamic performance.

  11. CONTROL FIRE ANTS BY USING DECAPITATING FLIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers with the USDA, ARS Biological Control of Pests Research Unit are rearing Pseudacteon curvatus, a tiny fly in the family Phoridae that parasitizes and kills imported fire ants. The flies only attack fire ants, and are not attracted to vegetables (12 kinds), fruit (13 kinds), raw meat (7 ...

  12. Heart Attack Risk Assessment

    MedlinePlus

    ... Pressure Tools & Resources Stroke More Heart Attack Risk Assessment Updated:May 31,2016 We're sorry, but ... Can You Recognize a Heart Attack? Quiz Risk Assessment Patient Information Sheets: Heart Attack Heart Attack Personal ...

  13. The first decapeptide adipokinetic hormone (AKH) in Heteroptera: a novel AKH from a South African saucer bug, Laccocoris spurcus (Naucoridae, Laccocorinae).

    PubMed

    Marco, Heather G; Simek, Petr; Gäde, Gerd

    2011-03-01

    A novel peptide of the adipokinetic hormone (AKH)/red pigment-concentrating hormone (RPCH) family has been elucidated by mass spectrometry from the corpora cardiaca of an African saucer bug species, Laccocoris spurcus. It is the first decapeptide member found in the species-rich taxon Heteroptera, has the primary sequence pGlu-Val-Asn-Phe-Ser-Pro-Ser-Trp-Gly-Gly amide and is denoted as Lacsp-AKH. The first eight amino acids are identical to the octapeptide Anaim-AKH of the European saucer bug, Ilyocoris cimicoides. The synthetic peptide Lacsp-AKH elevates lipids upon injection into the hemolymph of L. spurcus at a low dose of 3 pmol. Swimming activity in this saucer bug also causes a significant increase in the lipid concentration in the hemolymph. Thus, both results point to an apparent function of the endogenous new decapeptide Lacsp-AKH in L. spurcus, namely, to regulate lipid mobilization. Isolation of an AKH peptide from the corpora cardiaca of the water bug Aphelocheirus aestivalis (Aphelocheiridae) resulted in the assignment of the octapeptide Anaim-AKH, supporting current phylogenies on the infraorder Nepomorpha. PMID:20969908

  14. Heart Attack Recovery FAQs

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Heart Attack Recovery FAQs Updated:Aug 24,2016 Most people ... recovery. View an animation of a heart attack . Heart Attack Recovery Questions and Answers What treatments will I ...

  15. Flying Cars

    NASA Technical Reports Server (NTRS)

    Crow, Steven

    1996-01-01

    Flying cars have nearly mythical appeal to nonpilots, a group that includes almost the whole human race. The appeal resides in the perceived utility of flying cars, vehicles that offer portal-to-portal transportation, yet break the bonds of road and traffic and travel freely through the sky at the drivers will. Part of the appeal is an assumption that flying cars can be as easy to fly as to drive. Flying cars have been part of the dream of aviation since the dawn of powered flight. Glenn Curtiss built, displayed, and maybe even flew a flying car in 1917, the Curtiss Autoplane. Many roadable airplanes were built in the 1930's, like the Waterman Arrowbile and the Fulton Airphibian. Two flying cars came close to production in the early 1950's. Ted Hall built a series of flying cars culminating in the Convaircar, sponsored by Consolidated Vultee, General Motors, and Hertz. Molt Taylor built and certified his Aerocar, and Ford came close to producing them. Three Aerocars are still flyable, two in museums in Seattle and Oshkosh, and the third owned and flown by Ed Sweeny. Flying cars do have problems, which so far have prevented commercial success. An obvious problem is complexity of the vehicle, the infrastructure, or both. Another is the difficulty of matching low power for normal driving with high power in flight. An automobile uses only about 20 hp at traffic speeds, while a personal airplane needs about 160 hp at speeds typical of flight. Many automobile engines can deliver 160 hp, but not for very long. A more subtle issue involves the drag of automobiles and airplanes. A good personal airplane can fly 30 miles per gallon of fuel at 200 mph. A good sports car would need 660 hp at the same speed and would travel only 3 miles per gallon. The difference is drag area, about 4.5 sq ft for the automobile and 1.4 sq ft for the airplane. A flying car better have the drag area of the airplane, not the car!

  16. Heart attack first aid

    MedlinePlus

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

  17. About Heart Attacks

    MedlinePlus

    ... survive. A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or ... survive. A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or ...

  18. Pericarditis - after heart attack

    MedlinePlus

    ... medlineplus.gov/ency/article/000166.htm Pericarditis - after heart attack To use the sharing features on this page, ... occur in the days or weeks following a heart attack. Causes Two types of pericarditis can occur after ...

  19. Geology of the saucer-shaped sill near Mahad, western Deccan Traps, India, and its significance to the Flood Basalt Model

    NASA Astrophysics Data System (ADS)

    Duraiswami, Raymond A.; Shaikh, Tahira N.

    2013-07-01

    An ˜22-m-thick saucer-shaped sill occurs near Mahad and is exposed as a curvilinear, miniature ridge within the Deccan Traps. The sill has variable dips (42-55°). It has a 7.1-km long axis and 5.3 km short axis (aspect ratio of 1.4) and is larger than the MV sill of the Golden Valley sill complex, South Africa and the Panton sill, Australia. The sill has distinct glassy upper and lower chilled margins with a coarse-grained highly jointed core. The samples from the margin are invariably fractured and iron stained because of deuteric alteration. The rock from the sill is plagioclase-phyric basalt. At least three thick sill-like apophyses emanate from the base of the main sill. The apophyses change direction because of bending and thinning from a horizontal concordant sheet at the top to a discordant inclined form that bends again to pass into a lower horizontal concordant sheet. We interpret such features as `nascent saucer-shaped sills' that did not inflate to form nested sills. Geochemically, the sill consists of poorly differentiated tholeiitic basalt that has a restricted geochemical range. Critical trace element ratios and primitive mantle normalised trace and REE patterns indicate that the sills have geochemical affinities to the Poladpur chemical type and that the pahoehoe flow they intrude belongs to the Bushe Formation. Calculated magmatic overpressures during sill emplacement range from 8.4 to 11.3 MPa (for Young's modulus E = 5 GPa) and 16.7 to 22.5 MPa (for E=10 GPa) and depth to magma chamber ranges from 8.5 to 11.5 km ( E = 5 GPa) and 17.1 to 22.9 km ( E = 10 GPa), consistent with petrological and gravity modelling. The volume of the Mahad sill is approximately 276 km3 and is constant irrespective of the variations in the values of host-rock Young's modulus. In 1980, Cox (J Petrol 21:629-650, 1980) proposed a conceptual model of the crust-mantle section beneath the Karoo CFB which is considered as the fundamental model for flood basalt volcanism. Our

  20. Seven Deadliest Network Attacks

    SciTech Connect

    Prowell, Stacy J; Borkin, Michael; Kraus, Robert

    2010-05-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting networks? Then you need "Seven Deadliest Network Attacks". This book pinpoints the most dangerous hacks and exploits specific to networks, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: Denial of Service; War Dialing; Penetration 'Testing'; Protocol Tunneling; Spanning Tree Attacks; Man-in-the-Middle; and, Password Replay. Knowledge is power, find out about the most dominant attacks currently waging war on computers and networks globally. Discover the best ways to defend against these vicious attacks; step-by-step instruction shows you how. Institute countermeasures, don't be caught defenseless again, learn techniques to make your computer and network impenetrable.

  1. H33: A wheat gene providing Hessian fly resistance for the southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although more than 33 genes have been identified that confer resistance against Hessian fly attack in wheat, only five genes are currently effective against fly populations in the southeastern US. Because Hessian fly populations adapt to overcome newly deployed resistance genes within a few years of...

  2. A numerical approach to sill emplacement in isotropic media: Do saucer-shaped sills represent 'natural' intrusive tendencies in the shallow crust?

    NASA Astrophysics Data System (ADS)

    Hansen, Jógvan

    2015-11-01

    Saucer-shaped mafic sills are of common occurrences in sedimentary settings worldwide, but have only rarely been reported for onshore igneous settings. Mafic sills, which have intruded the lava pile of the Faroe Islands Basalt Group (FIBG) of the North Atlantic Igneous Province (NAIP), are characterised by gradual and continuous upward-curving geometries from bases to rims. Some of the smaller Faroese sills gradually wedge out to near-zero thicknesses at one of their ends, but these very thin sill sections still display gradual upward-curving geometries, despite the lack of any displacements of their overburdens that can be directly measured or detected with the unaided eye. This is at odds with earlier emplacement models applying for sedimentary settings, predicting sill climbing in response to stress asymmetries at their propagating tips due to wholesale overburden uplifts. In this paper, published values of Young's modulus for wet basaltic crust are utilised in order to calculate elastic displacements of isotropic host-rocks during individual small-scale inflation sequences in embryonic sills immediately behind their propagating tips at various depths and magmatic pressures. The calculations suggest that stress asymmetries at propagating tips and associated upward-curving sill climbing may occur when proportionally larger melt volumes are emplaced above initial single extension propagation fractures than below them. Angles of sill deflection are determined by differences in melt volumes deposited on top of and below initial planes of propagation fractures respectively, in addition to lengths of individual inflation sequences and magnitudes of magmatic pressures. The results obtained in this paper seem to suggest that asymmetrical small-scale inflation sequences at advancing sill tips in relatively isotropic media have the potential to generate saucer-shaped sills.

  3. LIGHT INTENSITY AFFECTS DISTRIBUTION OF ATTACKING PSEUDACTEON CURVATUS (DIPTERA: PHORIDAE) IN A LABORATORY REARING SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Distribution of attacking phorid flies (Pseudacteon curvatus Borgmeier) in a laboratory rearing system was tested for dependence on light intensity under 2 different light regimes. Light intensity (range, approx. 220-340 Lux) influenced fly distribution in light regime 1; in the second light regime...

  4. Cattle fly control using controlled-release insecticides.

    PubMed

    Tarry, D W

    1985-10-01

    Field trials were carried out from 1980 to 1984 on the use of a controlled-release pesticidal fly control technique on farms in Sussex, England, with a recurrent infectious keratoconjunctivitis problem related to fly attack. Pesticide impregnated p.v.c. ear-tags provided control of biting and disease-carrying fly species throughout the season. Over 90% control of flies, compared with untreated herds, was attained using 2 tags impregnated with cypermethrin, fenvalerate or flucythrinate, although control using a single tag was unsatisfactory. In all cases infectious keratoconjunctivitis was almost completely eliminated. PMID:4082447

  5. Sulfate attack on concrete with mineral admixtures

    SciTech Connect

    Irassar, E.F.; Di Maio, A.; Batic, O.R.

    1996-01-01

    The sulfate resistance of concretes containing fly ash, natural pozzolan and slag is investigated in a field test in which concrete specimens were half-buried in sulfate soil for five years. Mineral admixtures were used as a partial replacement for ordinary portland cement (C{sub 3}A = 8.5%), and the progress of sulfate attack was evaluated by several methods (visual rating, loss in mass, dynamic modulus, strength, X-ray analysis). Results of this study show that mineral admixtures improved the sulfate resistance when the concrete is buried in the soil. However, concretes with high content of mineral admixtures exhibit a greater surface scaling over soil level due to the sulfate salt crystallization. In this zone, capillary suction of concrete is the main mechanism of water and salt transportation. Concrete with 20% fly ash provides an integral solution for half-buried structures.

  6. Signs of a Heart Attack

    MedlinePlus

    ... attack Heart Health and Stroke Signs of a heart attack Related information Make the Call. Don't Miss ... to top More information on Signs of a heart attack Read more from womenshealth.gov Make the Call, ...

  7. Pericarditis - after heart attack

    MedlinePlus

    Dressler syndrome; Post-MI pericarditis; Post-cardiac injury syndrome; Postcardiotomy pericarditis ... Two types of pericarditis can occur after a heart attack . Early pericarditis: This form most occurs within ...

  8. Heart attack first aid

    MedlinePlus

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 ...

  9. Expression of a Wheat Gene Encoding a Type-1 Lipid Transfer Protein is Suppressed by Virulent Hessian Fly Larval Feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The response of wheat to attack by the Hessian fly is mediated by a gene-for-gene recognition involving wheat R genes and Hessian fly avr genes. Interactions are characterized as compatible when virulent Hessian fly larvae establish feeding sites and survive on wheat plants and incompatible when avi...

  10. Fly Away

    NASA Technical Reports Server (NTRS)

    Tibbitts, Scott

    2004-01-01

    Kurt was one of the lead engineers/project managers at our company, Starsys, in Boulder, Colorado. I had hired Kurt six years ago and found him to be a man of few words but huge actions. Kurt had single-handedly created two new business areas in the company and made a significant contribution to the upcoming Mars Exploration. While running in the mountains, Kurt had a fatal heart attack. An avid back country skier and climber, he was 45 years old and appeared in great health. I spoke honestly from my heart, and from my own experience as a father. That day people started to ask what they could do to help the family. Over the next couple days we set up a fund where people could contribute dollars or vacation time or comp time, and Starsya would translate that into equivalent dollars and provide a matching contribution.

  11. Sulfate resistance of high calcium fly ash concrete

    NASA Astrophysics Data System (ADS)

    Dhole, Rajaram

    Sulfate attack is one of the mechanisms which can cause deterioration of concrete. In general, Class C fly ash mixtures are reported to provide poor sulfate resistance. Fly ashes, mainly those belonging to the Class C, were tested as per the ASTM C 1012 procedure to evaluate chemical sulfate resistance. Overall the Class C fly ashes showed poor resistance in the sulfate environment. Different strategies were used in this research work to improve the sulfate resistance of Class C fly ash mixes. The study revealed that some of the strategies such as use of low W/CM (water to cementing materials by mass ratio), silica fume or ultra fine fly ash, high volumes of fly ash and, ternary or quaternary mixes with suitable supplementary cementing materials, can successfully improve the sulfate resistance of the Class C fly ash mixes. Combined sulfate attack, involving physical and chemical action, was studied using sodium sulfate and calcium sulfate solutions. The specimens were subjected to wetting-drying cycles and temperature changes. These conditions were found to accelerate the rate of degradation of concrete placed in a sodium sulfate environment. W/CM was found to be the main governing factor in providing sulfate resistance to mixes. Calcium sulfate did not reveal damage as a result of mainly physical action. Characterization of the selected fly ashes was undertaken by using SEM, XRD and the Rietveld analysis techniques, to determine the relation between the composition of fly ashes and resistance to sulfate attack. The chemical composition of glass represented on the ternary diagram was the main factor which had a significant influence on the sulfate resistance of fly ash mixtures. Mixes prepared with fly ashes containing significant amounts of vulnerable crystalline phases offered poor sulfate resistance. Comparatively, fly ash mixes containing inert crystalline phases such as quartz, mullite and hematite offered good sulfate resistance. The analysis of hydrated lime-fly

  12. Flying qualities research challenges

    NASA Technical Reports Server (NTRS)

    Sliwa, Steven M.; George, Frank L.

    1987-01-01

    Traditional flying qualities requirements for airplane dynamics are based on airplane modal response characteristics derived from linear small-perturbation analysis. These requirements are supported by a large experimental data base. The challenge to the flying qualities community is to demonstrate how flying qualities, the control system and aircraft configuration are still closely linked. This is evident in the definition of flying qualities and, as far as pilots are concerned, that flying qualities are still the measure of overall design success.

  13. Collaborative Attack vs. Collaborative Defense

    NASA Astrophysics Data System (ADS)

    Xu, Shouhuai

    We have witnessed many attacks in the cyberspace. However, most attacks are launched by individual attackers even though an attack may involve many compromised computers. In this paper, we envision what we believe to be the next generation cyber attacks — collaborative attacks. Collaborative attacks can be launched by multiple attackers (i.e., human attackers or criminal organizations), each of which may have some specialized expertise. This is possible because cyber attacks can become very sophisticated and specialization of attack expertise naturally becomes relevant. To counter collaborative attacks, we might need collaborative defense because each “chain” in a collaborative attack may be only adequately dealt with by a different defender. In order to understand collaborative attack and collaborative defense, we present a high-level abstracted framework for evaluating the effectiveness of collaborative defense against collaborative attacks. As a first step towards realizing and instantiating the framework, we explore a characterization of collaborative attacks and collaborative defense from the relevant perspectives.

  14. A fatal elephant attack.

    PubMed

    Hejna, Petr; Zátopková, Lenka; Safr, Miroslav

    2012-01-01

    A rare case of an elephant attack is presented. A 44-year-old man working as an elephant keeper was attacked by a cow elephant when he tripped over a foot chain while the animal was being medically treated. The man fell down and was consequently repeatedly attacked with elephant tusks. The man sustained multiple stab injuries to both groin regions, a penetrating injury to the abdominal wall with traumatic prolapse of the loops of the small bowel, multiple defects of the mesentery, and incomplete laceration of the abdominal aorta with massive bleeding into the abdominal cavity. In addition to the penetrating injuries, the man sustained multiple rib fractures with contusion of both lungs and laceration of the right lobe of the liver, and comminuted fractures of the pelvic arch and left femoral body. The man died shortly after he had been received at the hospital. The cause of death was attributed to traumatic shock. PMID:22085093

  15. Aerodynamic characteristics of flying fish in gliding flight.

    PubMed

    Park, Hyungmin; Choi, Haecheon

    2010-10-01

    The flying fish (family Exocoetidae) is an exceptional marine flying vertebrate, utilizing the advantages of moving in two different media, i.e. swimming in water and flying in air. Despite some physical limitations by moving in both water and air, the flying fish has evolved to have good aerodynamic designs (such as the hypertrophied fins and cylindrical body with a ventrally flattened surface) for proficient gliding flight. Hence, the morphological and behavioral adaptations of flying fish to aerial locomotion have attracted great interest from various fields including biology and aerodynamics. Several aspects of the flight of flying fish have been determined or conjectured from previous field observations and measurements of morphometric parameters. However, the detailed measurement of wing performance associated with its morphometry for identifying the characteristics of flight in flying fish has not been performed yet. Therefore, in the present study, we directly measure the aerodynamic forces and moment on darkedged-wing flying fish (Cypselurus hiraii) models and correlated them with morphological characteristics of wing (fin). The model configurations considered are: (1) both the pectoral and pelvic fins spread out, (2) only the pectoral fins spread with the pelvic fins folded, and (3) both fins folded. The role of the pelvic fins was found to increase the lift force and lift-to-drag ratio, which is confirmed by the jet-like flow structure existing between the pectoral and pelvic fins. With both the pectoral and pelvic fins spread, the longitudinal static stability is also more enhanced than that with the pelvic fins folded. For cases 1 and 2, the lift-to-drag ratio was maximum at attack angles of around 0 deg, where the attack angle is the angle between the longitudinal body axis and the flying direction. The lift coefficient is largest at attack angles around 30∼35 deg, at which the flying fish is observed to emerge from the sea surface. From glide polar

  16. Fatal crocodile attack.

    PubMed

    Chattopadhyay, Saurabh; Shee, Biplab; Sukul, Biswajit

    2013-11-01

    Attacks on human beings by various animals leading to varied types of injuries and even death in some cases are not uncommon. Crocodile attacks on humans have been reported from a number of countries across the globe. Deaths in such attacks are mostly due to mechanical injuries or drowning. Bites by the crocodiles often cause the limbs to be separated from the body. The present case refers to an incident of a fatal attack by a crocodile on a 35 years old female where only the mutilated head of the female was recovered. Multiple lacerated wounds over the face and scalp along with fracture of the cranial bones was detected on autopsy. Two distinct bite marks in the form of punched in holes were noted over the parietal and frontal bones. Injuries on the head with its traumatic amputation from the body were sufficient to cause death. However, the presence of other fatal injuries on the unrecovered body parts could not be ruled out. PMID:24237838

  17. Word Attack Model.

    ERIC Educational Resources Information Center

    Follettie, Joseph F.

    A limited analysis of alternative approaches to phonemic-level word attack instruction is provided in this document. The instruction segment begins with training in letter-sound correspondences for which mastery of certain skills is assumed. Instruction ends with the decoding of novel items having a consonant-vowel-consonant construction. Contents…

  18. Transient Ischemic Attack

    MedlinePlus Videos and Cool Tools

    ... to call 9-1-1 immediately for any stroke symptoms. Popular Topics TIA Cardiac Catheter Cholesterol Heart Attack Stent The content in this library is for educational purposes only, and therefore is not intended to be a substitute for professional medical advice, diagnosis or treatment.

  19. The importance of ecological studies in the control of tsetse flies*

    PubMed Central

    Glover, P. E.

    1967-01-01

    The author reviews recent ecological research on tsetse flies in East Africa and Northern Nigeria, particularly in connexion with the flies' sensory reactions, and stresses the importance of an accurate knowledge of their daytime and night-time resting-sites and of identifying the sources of their blood meals in order to elucidate the reservoirs of trypanosomiasis. The epidemiology of the disease is considered in the light of studies of trypanosome infections in host and fly. The control of tsetse flies must be based on the practical application of ecological knowledge by methods involving either a direct attack upon the fly (such as trapping or the use of insecticides) or an indirect attack (such as bush clearing or game destruction to eliminate the fly's habitat or food supply); these methods are dealt with in some detail. The author concludes with a discussion of modern trends in research, and a number of lines of research are suggested. PMID:4874781

  20. Development of botanical-based biopesticides and repellents against biting flies on livestock animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biting flies are important insect pests causing millions of dollars in losses to the livestock industry. The attack by biting flies causes significant losses in animal production and potential food contamination and disease transmission. This presentation reports our recent findings on the developme...

  1. Bacterial communities associated with larval development of stable flies (Diptera: Muscidae).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Adult stable flies are hematophagous parasites that preferentially feed on cattle. Persistent attacks and painful bites of the adults contribute to an economic impact of ~$2 billion/yr on the US cattle industry. Although stable flies are important livestock pests, relatively little is ...

  2. Grapefruit as a host for the West Indian fruit fly (Diptera: Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most common hosts for the West Indian fruit fly, Anastrepha oblique (Macquart), are fruits of the family Anacardiaceae (mangos and mombin species). However, similar to many of the tropical fruit flies of major economic importance, this species attacks several other families of crop fruit, inclu...

  3. Stable Fly Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult stable flies feed on the blood of humans, pets and livestock, inflicting painful bites. Stable flies need one and sometimes two bloodmeals each day to develop their eggs. Unlike mosquitoes where only the females bloodfeed, both male and female stable flies require blood to reproduce. Stable fl...

  4. Facial dog attack injuries.

    PubMed

    Lin, Wei; Patil, Pavan Manohar

    2015-02-01

    The exposed position of the face makes it vulnerable to dog bite injuries. This fact combined with the short stature of children makes them a high-risk group for such attacks. In contrast to wounds inflicted by assaults and accidents, dog bite wounds are deep puncture type wounds compounded by the presence of pathologic bacteria from the saliva of the attacking dog. This, combined with the presence of crushed, devitalized tissue makes these wounds highly susceptible to infection. Key to successful management of such wounds are meticulous cleansing of the wound, careful debridement, primary repair, appropriate antibiotic therapy, and rabies and tetanus immunization where indicated. This review presents an overview of the epidemiology, presentation, management of such emergencies, and the recent advances in the care of such patients. PMID:25829713

  5. Investigation of gliding flight by flying fish

    NASA Astrophysics Data System (ADS)

    Park, Hyungmin; Jeon, Woo-Pyung; Choi, Haecheon

    2006-11-01

    The most successful flight capability of fish is observed in the flying fish. Furthermore, despite the difference between two medium (air and water), the flying fish is well evolved to have an excellent gliding performance as well as fast swimming capability. In this study, flying fish's morphological adaptation to gliding flight is experimentally investigated using dry-mounted darkedged-wing flying fish, Cypselurus Hiraii. Specifically, we examine the effects of the pectoral and pelvic fins on the aerodynamic performance considering (i) both pectoral and pelvic fins, (ii) pectoral fins only, and (iii) body only with both fins folded. Varying the attack angle, we measure the lift, drag and pitching moment at the free-stream velocity of 12m/s for each case. Case (i) has higher lift-to-drag ratio (i.e. longer gliding distance) and more enhanced longitudinal static stability than case (ii). However, the lift coefficient is smaller for case (i) than for case (ii), indicating that the pelvic fins are not so beneficial for wing loading. The gliding performance of flying fish is compared with those of other fliers and is found to be similar to those of insects such as the butterfly and fruitfly.

  6. When women attack.

    PubMed

    McLaughlin, Bryan; Davis, Catasha; Coppini, David; Kim, Young Mie; Knisely, Sandra; McLeod, Douglas

    2015-01-01

    The common assumption that female candidates on the campaign trail should not go on the attack, because such tactics contradict gender stereotypes, has not received consistent support. We argue that in some circumstances gender stereotypes will favor female politicians going negative. To test this proposition, this study examines how gender cues affect voter reactions to negative ads in the context of a political sex scandal, a context that should prime gender stereotypes that favor females. Using an online experiment involving a national sample of U.S. adults (N = 599), we manipulate the gender and partisan affiliation of a politician who attacks a male opponent caught in a sex scandal involving sexually suggestive texting to a female intern. Results show that in the context of a sex scandal, a female candidate going on the attack is evaluated more positively than a male. Moreover, while female participants viewed the female sponsor more favorably, sponsor gender had no effect on male participants. Partisanship also influenced candidate evaluations: the Democratic female candidate was evaluated more favorably than her Republican female counterpart. PMID:26399945

  7. Larval Defense against Attack from Parasitoid Wasps Requires Nociceptive Neurons

    PubMed Central

    Robertson, Jessica L.; Tsubouchi, Asako; Tracey, W. Daniel

    2013-01-01

    Parasitoid wasps are a fierce predator of Drosophila larvae. Female Leptopilina boulardi (LB) wasps use a sharp ovipositor to inject eggs into the bodies of Drosophila melanogaster larvae. The wasp then eats the Drosophila larva alive from the inside, and an adult wasp ecloses from the Drosophila pupal case instead of a fly. However, the Drosophila larvae are not defenseless as they may resist the attack of the wasps through somatosensory-triggered behavioral responses. Here we describe the full range of behaviors performed by the larval prey in immediate response to attacks by the wasps. Our results suggest that Drosophila larvae primarily sense the wasps using their mechanosensory systems. The range of behavioral responses included both “gentle touch” like responses as well as nociceptive responses. We found that the precise larval response depended on both the somatotopic location of the attack, and whether or not the larval cuticle was successfully penetrated during the course of the attack. Interestingly, nociceptive responses are more likely to be triggered by attacks in which the cuticle had been successfully penetrated by the wasp. Finally, we found that the class IV neurons, which are necessary for mechanical nociception, were also necessary for a nociceptive response to wasp attacks. Thus, the class IV neurons allow for a nociceptive behavioral response to a naturally occurring predator of Drosophila. PMID:24205297

  8. The interpretation of flying qualities requirements for flight control design

    NASA Technical Reports Server (NTRS)

    Rynaski, E. G.; Weingarten, N. C.; Grantham, W.

    1986-01-01

    The flying requirements of MIL-F-8785(C) are interpreted in terms of command/response configurations, and pilot preference for flight control systems configurations of angle of attack, or pitch rate command, specified independently for the short period and phugoid dynamics, is determined using the Total-In-Flight-Simulator aircraft. The results show that for either command configuration, the short term response applies to the angle of attack response of the vehicle, and that this response must satisfy the omega(n) vs n/alpha requirement. The preference in the long term for angle of attack command indicates that the pilot wants the aircraft to fly in the direction it is pointing, and an attitude hold system is not found to be preferred unless attitude hold results in flight path angle hold.

  9. X-31 at High Angle of Attack

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The X-31 aircraft, on a research mission from NASA's Dryden Flight Research Center, Edwards, California, is flying nearly perpendicular to the flight path while performing the Herbst maneuver. Effectively using the entire airframe as a speed brake and using the aircraft's unique thrust vectoring system to maintain control, the pilot rapidly rolls the aircraft to reverse the direction of flight, completing the maneuver with acceleration back to high speed in the opposite direction. This type of turning capability could reduce the turning time of a fighter aircraft by 30 percent. The Herbst maneuver was first conducted in an X-31 on April 29, 1993, in the No. 2 X-31 aircraft by German test pilot Karl-Heinz Lang. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal

  10. X-31 at High Angle of Attack

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The X-31 aircraft, on a research mission from NASA's Dryden Flight Research Center, Edwards, California, is flying nearly perpendicular to the flight path while performing the Herbst maneuver. Effectively using the entire airframe as a speed brake and using the aircrafts unique thrust vectoring system to maintain control, the pilot rapidly rolls the aircraft to reverse the direction of flight, completing the maneuver with acceleration back to high speed in the opposite direction. This type of turning capability could reduce the turning time of a fighter aircraft by 30 percent. The Herbst maneuver was first conducted in an X-31 on April 29, 1993, in the No. 2 X-31 aircraft by German test pilot Karl-Heinz Lang. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal

  11. X-31 at High Angle of Attack

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The X-31 aircraft on a research mission from NASA's Dryden Flight Research Center, Edwards, California, is flying nearly perpendicular to the flight path while performing the Herbst maneuver. Effectively using the entire airframe as a speed brake and using the aircrafts unique thrust vectoring system to maintain control, the pilot rapidly rolls the aircraft to reverse the direction of flight, completing the maneuver with acceleration back to high speed in the opposite direction. This type of turning capability could reduce the turning time of a fighter aircraft by 30 percent. The Herbst maneuver was first conducted in an X-31 on April 29, 1993, in the No. 2 X-31 aircraft by German test pilot Karl-Heinz Lang. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal

  12. Lift enhancement in flying snakes

    NASA Astrophysics Data System (ADS)

    Krishnan, Anush; Socha, John; Vlachos, Pavlos; Barba, Lorena

    2013-11-01

    Flying snakes use a unique method of aerial locomotion: they jump from tree branches, flatten their bodies and undulate through the air to produce a glide. The shape of their body cross-section during the glide plays an important role in generating lift. We present a computational investigation of the aerodynamics of the cross-sectional shape. We performed two-dimensional simulations of incompressible flow past the anatomically correct cross-section of the species Chrysopelea paradisi, which show that a significant enhancement in lift appears at an angle of attack of 35 degrees, for Reynolds numbers 2000 and above. Previous experiments on physical models also demonstrated an increased lift and at the same angle of attack. The simulations point to the lift enhancement arising from the early separation of the boundary layer on the dorsal surface of the snake profile, without stall. The separated shear layer rolls up and interacts with secondary vorticity in the near-wake, inducing the primary vortex to remain closer to the body and thus cause enhanced suction, resulting in higher lift. In physical experiments, the flow is inherently 3-D due to fluid instabilities, and it is intriguing that the enhanced lift also appears in the two-dimensional simulations.

  13. Improving Attack Graph Visualization through Data Reduction and Attack Grouping

    SciTech Connect

    John Homer; Ashok Varikuti; Xinming Ou; Miles A. McQueen

    2008-09-01

    Various tools exist to analyze enterprise network systems and to produce attack graphs detailing how attackers might penetrate into the system. These attack graphs, however, are often complex and difficult to comprehend fully, and a human user may find it problematic to reach appropriate configuration decisions. This paper presents methodologies that can 1) automatically identify portions of an attack graph that do not help a user to understand the core security problems and so can be trimmed, and 2) automatically group similar attack steps as virtual nodes in a model of the network topology, to immediately increase the understandability of the data. We believe both methods are important steps toward improving visualization of attack graphs to make them more useful in configuration management for large enterprise networks. We implemented our methods using one of the existing attack-graph toolkits. Initial experimentation shows that the proposed approaches can 1) significantly reduce the complexity of attack graphs by trimming a large portion of the graph that is not needed for a user to understand the security problem, and 2) significantly increase the accessibility and understandability of the data presented in the attack graph by clearly showing, within a generated visualization of the network topology, the number and type of potential attacks to which each host is exposed.

  14. Fly ash carbon passivation

    DOEpatents

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  15. Sulfate attack expansion mechanisms

    SciTech Connect

    Müllauer, Wolfram Beddoe, Robin E.; Heinz, Detlef

    2013-10-15

    A specially constructed stress cell was used to measure the stress generated in thin-walled Portland cement mortar cylinders caused by external sulfate attack. The effects of sulfate concentration of the storage solution and C{sub 3}A content of the cement were studied. Changes in mineralogical composition and pore size distribution were investigated by X-ray diffraction and mercury intrusion porosimetry, respectively. Damage is due to the formation of ettringite in small pores (10–50 nm) which generates stresses up to 8 MPa exceeding the tensile strength of the binder matrix. Higher sulfate concentrations and C{sub 3}A contents result in higher stresses. The results can be understood in terms of the effect of crystal surface energy and size on supersaturation and crystal growth pressure.

  16. Sound radiation around a flying fly

    NASA Astrophysics Data System (ADS)

    Sueur, Jérôme; Tuck, Elizabeth J.; Robert, Daniel

    2005-07-01

    Many insects produce sounds during flight. These acoustic emissions result from the oscillation of the wings in air. To date, most studies have measured the frequency characteristics of flight sounds, leaving other acoustic characteristics-and their possible biological functions-unexplored. Here, using close-range acoustic recording, we describe both the directional radiation pattern and the detailed frequency composition of the sound produced by a tethered flying (Lucilia sericata). The flapping wings produce a sound wave consisting of a series of harmonics, the first harmonic occurring around 190 Hz. In the horizontal plane of the fly, the first harmonic shows a dipolelike amplitude distribution whereas the second harmonic shows a monopolelike radiation pattern. The first frequency component is dominant in front of the fly while the second harmonic is dominant at the sides. Sound with a broad frequency content, typical of that produced by wind, is also recorded at the back of the fly. This sound qualifies as pseudo-sound and results from the vortices generated during wing kinematics. Frequency and amplitude features may be used by flies in different behavioral contexts such as sexual communication, competitive communication, or navigation within the environment.

  17. The Ability of selected Pupal Parasitoids (Hymenoptera: Pteromalidae) to Locate Stable Fly Hosts in a Soiled Equine Bedding Substrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory evaluations assessing the ability of Spalangia cameroni Perkins, Spalangia endius Walker, and Muscidifurax raptorellus Kogan and Legner to locate and attack stable fly hosts in a field-collected fly-breeding substrate suggest that Spalangia spp. are more suited to successfully locate and ...

  18. Ever Fly a Tetrahedron?

    ERIC Educational Resources Information Center

    King, Kenneth

    2004-01-01

    Few things capture the spirit of spring like flying a kite. Watching a kite dance and sail across a cloud spotted sky is not only a visually appealing experience it also provides a foundation for studies in science and mathematics. Put simply, a kite is an airfoil surface that flies when the forces of lift and thrust are greater than the forces of…

  19. Activation of fly ash

    DOEpatents

    Corbin, David R.; Velenyi, Louis J.; Pepera, Marc A.; Dolhyj, Serge R.

    1986-01-01

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  20. Activation of fly ash

    DOEpatents

    Corbin, D.R.; Velenyi, L.J.; Pepera, M.A.; Dolhyj, S.R.

    1986-08-19

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  1. A Flying Summer Camp

    ERIC Educational Resources Information Center

    Mercurio, Frank X.

    1975-01-01

    Describes a five-day summer camp which provided 12 children, ages 9-14, with a complete flying experience. The training consisted of ground school and one hour actual flying time, including the basics of aircraft control and a flight prepared and executed by the students. (MLH)

  2. Thrombolytic drugs for heart attack

    MedlinePlus

    ... attack URL of this page: //medlineplus.gov/ency/article/007488.htm Thrombolytic drugs for heart attack To use the sharing features on this page, ... the management of patients with non-ST-elevation acute coronary syndromes: a report ... myocardial infarction: a report of the American College of Cardiology ...

  3. WILD PIG ATTACKS ON HUMANS

    SciTech Connect

    Mayer, J.

    2013-04-12

    Attacks on humans by wild pigs (Sus scrofa) have been documented since ancient times. However, studies characterizing these incidents are lacking. In an effort to better understand this phenomenon, information was collected from 412 wild pig attacks on humans. Similar to studies of large predator attacks on humans, data came from a variety of sources. The various attacks compiled occurred in seven zoogeographic realms. Most attacks occurred within the species native range, and specifically in rural areas. The occurrence was highest during the winter months and daylight hours. Most happened under non-hunting circumstances and appeared to be unprovoked. Wounded animals were the chief cause of these attacks in hunting situations. The animals involved were typically solitary, male and large in size. The fate of the wild pigs involved in these attacks varied depending upon the circumstances, however, most escaped uninjured. Most human victims were adult males traveling on foot and alone. The most frequent outcome for these victims was physical contact/mauling. The severity of resulting injuries ranged from minor to fatal. Most of the mauled victims had injuries to only one part of their bodies, with legs/feet being the most frequent body part injured. Injuries were primarily in the form of lacerations and punctures. Fatalities were typically due to blood loss. In some cases, serious infections or toxemia resulted from the injuries. Other species (i.e., pets and livestock) were also accompanying some of the humans during these attacks. The fates of these animals varied from escaping uninjured to being killed. Frequency data on both non-hunting and hunting incidents of wild pig attacks on humans at the Savannah River Site, South Carolina, showed quantitatively that such incidents are rare.

  4. X-31 high angle of attack control system performance

    NASA Technical Reports Server (NTRS)

    Huber, Peter; Seamount, Patricia

    1994-01-01

    The design goals for the X-31 flight control system were: (1) level 1 handling qualities during post-stall maneuvering (30 to 70 degrees angle-of-attack); (2) thrust vectoring to enhance performance across the flight envelope; and (3) adequate pitch-down authority at high angle-of-attack. Additional performance goals are discussed. A description of the flight control system is presented, highlighting flight control system features in the pitch and roll axes and X-31 thrust vectoring characteristics. The high angle-of-attack envelope clearance approach will be described, including a brief explanation of analysis techniques and tools. Also, problems encountered during envelope expansion will be discussed. This presentation emphasizes control system solutions to problems encountered in envelope expansion. An essentially 'care free' envelope was cleared for the close-in-combat demonstrator phase. High angle-of-attack flying qualities maneuvers are currently being flown and evaluated. These results are compared with pilot opinions expressed during the close-in-combat program and with results obtained from the F-18 HARV for identical maneuvers. The status and preliminary results of these tests are discussed.

  5. Evaluation of a transient barrier trapping system to manage the canyon fly (Diptera: Muscidae).

    PubMed

    Ekanayake, Panchali K; Gerry, Alec C

    2014-01-01

    ABSTRACT A circular perimeter barrier of CO,-baited Centers for Disease Control and Prevention (CDC) suction traps (without the light) was placed at a hilltop location in southern California known for high "canyon fly" activity, to determine whether a transiently operated barrier trapping system using attractive traps would reduce the number of these nuisance flies to successfully reach a human host within the protected area Preliminary studies demonstrated that the number of flies captured by a human host was reduced when a single CO2 trap was placed < or =20 m from the host, an indication that these traps are attractive enough to reduce fly pressure on nearby human hosts. The use of eight transiently operated CO2 traps placed equidistant along either a 15- or 5-m radius barrier perimeter significantly reduced the number of flies to reach a human host within the protected area Attack rates at the protected human host were reduced by a maximum of 51% in the presence of a protective barrier. However, with attack rates on a human host in the hundreds of flies per minute at the study site, this level of protection was not deemed sufficient for recommendation of this technique to homeowners or others who want temporary suppression of these nuisance flies in a limited area, such as a backyard. Implications of using a transient barrier trapping system to manage canyon flies are discussed. PMID:24605462

  6. Attack vulnerability of complex networks

    NASA Astrophysics Data System (ADS)

    Holme, Petter; Kim, Beom Jun; Yoon, Chang No; Han, Seung Kee

    2002-05-01

    We study the response of complex networks subject to attacks on vertices and edges. Several existing complex network models as well as real-world networks of scientific collaborations and Internet traffic are numerically investigated, and the network performance is quantitatively measured by the average inverse geodesic length and the size of the largest connected subgraph. For each case of attacks on vertices and edges, four different attacking strategies are used: removals by the descending order of the degree and the betweenness centrality, calculated for either the initial network or the current network during the removal procedure. It is found that the removals by the recalculated degrees and betweenness centralities are often more harmful than the attack strategies based on the initial network, suggesting that the network structure changes as important vertices or edges are removed. Furthermore, the correlation between the betweenness centrality and the degree in complex networks is studied.

  7. Genetic attack on neural cryptography

    SciTech Connect

    Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

    2006-03-15

    Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

  8. Repellent Properties of δ-Octalactone Against the Tsetse Fly, Glossina morsitans Morsitans

    PubMed Central

    Mwangi, Martin T.; Gikonyo, Nicholas K.; Ndiege, Isaiah O.

    2008-01-01

    δ-octalactone, produced by several Bovidae, has been suggested as a potential repellant of tsetse fly attack. Racemic δ-octalactone was synthesized via an abbreviated route. The product was assayed against 3-day old starved teneral female tsetse flies, Glossina morsitans morsitans Wiedemann (Diptera: Glossinidae), in a choice wind tunnel and found to be a potent tsetse repellent at doses ≥0.05 mg in 200 µl of paraffin oil (0.05 >p >0.01). PMID:20298116

  9. Additive attacks on speaker recognition

    NASA Astrophysics Data System (ADS)

    Farrokh Baroughi, Alireza; Craver, Scott

    2014-02-01

    Speaker recognition is used to identify a speaker's voice from among a group of known speakers. A common method of speaker recognition is a classification based on cepstral coefficients of the speaker's voice, using a Gaussian mixture model (GMM) to model each speaker. In this paper we try to fool a speaker recognition system using additive noise such that an intruder is recognized as a target user. Our attack uses a mixture selected from a target user's GMM model, inverting the cepstral transformation to produce noise samples. In our 5 speaker data base, we achieve an attack success rate of 50% with a noise signal at 10dB SNR, and 95% by increasing noise power to 0dB SNR. The importance of this attack is its simplicity and flexibility: it can be employed in real time with no processing of an attacker's voice, and little computation is needed at the moment of detection, allowing the attack to be performed by a small portable device. For any target user, knowing that user's model or voice sample is sufficient to compute the attack signal, and it is enough that the intruder plays it while he/she is uttering to be classiffed as the victim.

  10. Initial flight test of a ground deployed system for flying qualities assessment

    NASA Technical Reports Server (NTRS)

    Shafer, Mary F.; Koehler, Ruthard; Wilson, Edward M.; Levy, David R.

    1989-01-01

    In order to provide a safe, repeatable, precise, high-gain flying qualities task a ground deployed system was developed and tested at the NASA Ames Research Center's Dryden Flight Research Facility. This system, the adaptable target lighting array system (ATLAS), is based on the German Aerospace Research Establishment's ground attack test equipment (GRATE). These systems provide a flying-qualities task, emulating the ground-attack task with ground deployed lighted targets. These targets light in an unpredictable sequence and the pilot has to aim the aircraft at whichever target is lighted. Two flight-test programs were used to assess the suitability of ATLAS. The first program used the United States Air Force (USAF) NT-33A variability stability aircraft to establish that ATLAS provided a task suitable for use in flying qualities research. A head-up display (HUD) tracking task was used for comparison. The second program used the X-29A forward-swept wing aircraft to demonstrate that the ATLAS task was suitable for assessing the flying qualities of a specific experimental aircraft. In this program, the ground-attack task was used for comparison. All pilots who used ATLAS found it be highly satisfactory and thought it to be superior to the other tasks used in flying qualities evaluations. It was recommended that ATLAS become a standard for flying qualities evaluations.

  11. Eyespots divert attacks by fish.

    PubMed

    Kjernsmo, Karin; Merilaita, Sami

    2013-09-01

    Eyespots (colour patterns consisting of concentric rings) are found in a wide range of animal taxa and are often assumed to have an anti-predator function. Previous experiments have found strong evidence for an intimidating effect of eyespots against passerine birds. Some eyespots have been suggested to increase prey survival by diverting attacks towards less vital body parts or a direction that would facilitate escape. While eyespots in aquatic environments are widespread, their function is extremely understudied. Therefore, we investigated the protective function of eyespots against attacking fish. We used artificial prey and predator-naive three-spined sticklebacks (Gasterosteus aculeatus) as predators to test both the diversion (deflection) and the intimidation hypothesis. Interestingly, our results showed that eyespots smaller than the fish' own eye very effectively draw the attacks of the fish towards them. Furthermore, our experiment also showed that this was not due to the conspicuousness of the eyespot, because attack latency did not differ between prey items with and without eyespots. We found little support for an intimidating effect by larger eyespots. Even though also other markings might misdirect attacks, we can conclude that the misdirecting function may have played an important role in the evolution of eyespots in aquatic environments. PMID:23864602

  12. Analytical Characterization of Internet Security Attacks

    ERIC Educational Resources Information Center

    Sellke, Sarah H.

    2010-01-01

    Internet security attacks have drawn significant attention due to their enormously adverse impact. These attacks includes Malware (Viruses, Worms, Trojan Horse), Denial of Service, Packet Sniffer, and Password Attacks. There is an increasing need to provide adequate defense mechanisms against these attacks. My thesis proposal deals with analytical…

  13. The interpretation of flying qualities requirements for flight control system design

    NASA Technical Reports Server (NTRS)

    Rynaski, E. G.

    1985-01-01

    An experimental flight test program was designed for the Total In Flight Simulator (TIFS) directed toward the interface between flying qualities requirements and flight control system design criteria. The eventual goal is to provide an interpretation or translation of flying qualities requirements for use by the flight control system designer. Specifically, an angle of attack and pitch rate command system matrix involving both short term and long term dynamics are specified for evaluation. Flying qualities criteria and flight control system configuration or architecture can be independent was demonstrated. Finally, additional configurations are proposed to evaluate the efficacy of dynamic decoupling.

  14. Autonomous Flying Controls Testbed

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.

    2005-01-01

    The Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis,Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights.

  15. Pseudacteon decapitating flies (Diptera: Phoridae): Are they potential vectors of the fire ant pathogens Kneallhazia(=Thelohania)solenopsae (Microsporidia: Thelohaniidae)and Vairimorpha invictae (Microsporidia: Burenellidae)?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fire ant decapitating flies in the genus Pseudacteon were tested for their potential as hosts or vectors of two microsporidian pathogens of the red imported fire ant, Solenopsis invicta. Decapitating flies which attacked or were reared from S. invicta workers infected by Kneallhazia (=Thelohania)...

  16. Complexity and Fly Swarms

    NASA Astrophysics Data System (ADS)

    Cates, Grant; Murray, Joelle

    Complexity is the study of phenomena that emerge from a collection of interacting objects and arises in many systems throughout physics, biology, finance, economics and more. Certain kinds of complex systems can be described by self-organized criticality (SOC). An SOC system is one that is internally driven towards some critical state. Recent experimental work suggests scaling behavior of fly swarms-one of the hallmarks of an SOC system. Our goal is to look for SOC behavior in computational models of fly swarms.

  17. Chemically activated fly ash (CAFA): A new type of fly ash based cement

    SciTech Connect

    Rostami, H.; Silverstrim, T.

    1996-12-31

    A new cementitious material has been developed, called Chemically Activated Fly Ash (CAFA), which is used to produce concrete for construction. CAFA can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economy. CAFA contains 80--95% Class F fly ash and is used as cement to bind sand, stone, and fibers creating concrete. CAFA concrete has been tested for strength, durability, mechanical properties and, most importantly, economic viability. CAFA concrete is economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of Ultimate in 1 day), high ultimate strengths (16,000 psi in 1 day), excellent acid resistance, and freeze thaw durability. CAFA`s resistance to chemical attack, such as, sulfuric (H{sub 2}SO{sub 4}), nitric (HNO{sub 3}), hydrochloric (HCl), and organic acids, is far better than portland cement concrete. CAFA is resistant to freeze thaw attack based on ASTM C-666 specification. Near term applications of CAFA material are, blocks, pipe, burial vaults, median barriers, sound barriers, and overlaying materials. Eventual markets are high strength construction products, bridge beams, prestressed members, concrete tanks, highway appurtenances, and other concrete products.

  18. Flight test of the X-29A at high angle of attack: Flight dynamics and controls

    NASA Technical Reports Server (NTRS)

    Bauer, Jeffrey E.; Clarke, Robert; Burken, John J.

    1995-01-01

    The NASA Dryden Flight Research Center has flight tested two X-29A aircraft at low and high angles of attack. The high-angle-of-attack tests evaluate the feasibility of integrated X-29A technologies. More specific objectives focus on evaluating the high-angle-of-attack flying qualities, defining multiaxis controllability limits, and determining the maximum pitch-pointing capability. A pilot-selectable gain system allows examination of tradeoffs in airplane stability and maneuverability. Basic fighter maneuvers provide qualitative evaluation. Bank angle captures permit qualitative data analysis. This paper discusses the design goals and approach for high-angle-of-attack control laws and provides results from the envelope expansion and handling qualities testing at intermediate angles of attack. Comparisons of the flight test results to the predictions are made where appropriate. The pitch rate command structure of the longitudinal control system is shown to be a valid design for high-angle-of-attack control laws. Flight test results show that wing rock amplitude was overpredicted and aileron and rudder effectiveness were underpredicted. Flight tests show the X-29A airplane to be a good aircraft up to 40 deg angle of attack.

  19. Economic Impact of Stable Flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dynamic model was created to estimate the economic impact of stable flies on livestock production. Based upon a nationwide average of 10 stable flies per animal for 3 months per year, the model estimates the impact of stable flies to be $543 million to the dairy industry, $1.34 billion to pasture ...

  20. Flying High with Spring.

    ERIC Educational Resources Information Center

    Harrington, Carolyn Lang

    2000-01-01

    Presents an art activity for first grade that uses multicolor scratch paper. Explains that students make scratch-drawings of bird nests, then, as a class, discuss types of birds and bird positions (such as sitting or flying), and finally each creates a bird to add to the nest. (CMK)

  1. Fly on the Wall

    ERIC Educational Resources Information Center

    Berry, Dave; Korpan, Cynthia

    2009-01-01

    This paper describes the implementation of a peer observation program at the University of Victoria called the Lecture Club. The observers are not interactive during the class--they are the proverbial flies on the wall. The paper identifies the program as self-developmental, discussing the attributes of this learning-to-teach and peer-sharing…

  2. Learning to Fly.

    ERIC Educational Resources Information Center

    Weil, Patricia E.

    1983-01-01

    Presents information on where to learn to fly, which aircraft is best for this purpose, and approximate costs. Includes additional information on certificates, licenses, and ratings, and a description of the two phases of the General Aviation Manufacturers Association flight training program. (JN)

  3. Go Fly a Kite

    ERIC Educational Resources Information Center

    Klopack, Ken

    2009-01-01

    This article describes an "art kite" activity. The idea is to construct and decorate a non-flying kite that they could display for an art exhibit. Through the activity, students learn to give and take suggestions from one another, improve the quality of their work and set a wonderful atmosphere of collaboration. (Contains 1 online resource.)

  4. Fly-ash utilization

    SciTech Connect

    Lockerby, R.W.

    1984-01-01

    The over 200 references in this bibliography cover some of the uses found for fly-ash, which range from the manufacture of bricks and as a new type of concrete to the recovery of aluminum and other valuable ores from the ash. The entries are grouped under seven headings: General, Agriculture, Brickmaking, Cement/Concrete, Land Reclamation, Resource Recovery, and Other.

  5. Wisdom from the fly.

    PubMed

    Rieder, Leila E; Larschan, Erica N

    2014-11-01

    Arguably, almost all research in Drosophila can be considered basic research, yet many of the most essential and fundamental concepts of human genetics were first decoded in the fly. Although the fly genome, which is organized into only four chromosomes, is approximately one-twentieth the size of the human genome, it contains roughly the same number of genes, and up to 75% of human disease-related genes have Drosophila homologues [1]. The fly was prized for its simplicity and utility even before such compelling homology with humans was apparent. Since Thomas Hunt Morgan began his seminal experiments over a century ago (Table 1), the Drosophila system has revealed countless key mechanisms by which cells function, including the factors that maintain chromatin and the signaling pathways that control cell fate determination and organism development. More recently, the fly has emerged as a critical neurobiological tool and disease model for a range of genetic disorders. In this review, we present a brief retrospective of Drosophila as an indispensable genetic system and discuss some of the many contributions, past and present, of this facile system to human genetics. PMID:25161083

  6. Evaluation of Word Attack Skills.

    ERIC Educational Resources Information Center

    Follettie, Joseph F.

    A framework for more apt and sensitive evaluation of generalized word attack skill--the heart of oral reading skill--is presented. The paper envisions the design and development of oral reading instruction as bounded by a fully-specified evaluation scheme. (Author)

  7. Detection of complex cyber attacks

    NASA Astrophysics Data System (ADS)

    Gregorio-de Souza, Ian; Berk, Vincent H.; Giani, Annarita; Bakos, George; Bates, Marion; Cybenko, George; Madory, Doug

    2006-05-01

    One significant drawback to currently available security products is their inabilty to correlate diverse sensor input. For instance, by only using network intrusion detection data, a root kit installed through a weak username-password combination may go unnoticed. Similarly, an administrator may never make the link between deteriorating response times from the database server and an attacker exfiltrating trusted data, if these facts aren't presented together. Current Security Information Management Systems (SIMS) can collect and represent diverse data but lack sufficient correlation algorithms. By using a Process Query System, we were able to quickly bring together data flowing from many sources, including NIDS, HIDS, server logs, CPU load and memory usage, etc. We constructed PQS models that describe dynamic behavior of complicated attacks and failures, allowing us to detect and differentiate simultaneous sophisticated attacks on a target network. In this paper, we discuss the benefits of implementing such a multistage cyber attack detection system using PQS. We focus on how data from multiple sources can be combined and used to detect and track comprehensive network security events that go unnoticed using conventional tools.

  8. 57 Word Attack Skill Games.

    ERIC Educational Resources Information Center

    Mara, Patricia; Sorenson, Juanita

    These 57 game cards were developed to help teachers build their resource files for word-attack skills. Cards are keyed to skills suggested by the Wisconsin Design for Reading Skill Development and are color-coded according to their appropriateness for children in kindergarten through grade three. The front of each card gives the name of the skill,…

  9. Attack Vulnerability of Network Controllability.

    PubMed

    Lu, Zhe-Ming; Li, Xin-Feng

    2016-01-01

    Controllability of complex networks has attracted much attention, and understanding the robustness of network controllability against potential attacks and failures is of practical significance. In this paper, we systematically investigate the attack vulnerability of network controllability for the canonical model networks as well as the real-world networks subject to attacks on nodes and edges. The attack strategies are selected based on degree and betweenness centralities calculated for either the initial network or the current network during the removal, among which random failure is as a comparison. It is found that the node-based strategies are often more harmful to the network controllability than the edge-based ones, and so are the recalculated strategies than their counterparts. The Barabási-Albert scale-free model, which has a highly biased structure, proves to be the most vulnerable of the tested model networks. In contrast, the Erdős-Rényi random model, which lacks structural bias, exhibits much better robustness to both node-based and edge-based attacks. We also survey the control robustness of 25 real-world networks, and the numerical results show that most real networks are control robust to random node failures, which has not been observed in the model networks. And the recalculated betweenness-based strategy is the most efficient way to harm the controllability of real-world networks. Besides, we find that the edge degree is not a good quantity to measure the importance of an edge in terms of network controllability. PMID:27588941

  10. EVALUATION OF SEQUENTIAL EXPOSURE OF IRRADIATED HOSTS TO MAXIMIZE THE MASS REARING OF FRUIT FLY PARASITOIDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of evaluations were carried out to assess the feasibility of sequentially exposing tephritid hosts to two different parasitoid species, thus allowing unparasitized flies to be attacked and optimizing the production in natural enemy mass-rearing programs. Larvae or pupae of Anastrepha ludens...

  11. Bait formulations of attractants and phagostimulants for targeted, area-wide fruit fly control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tephritid fruit flies attack hundreds of species of fruits and vegetables and are responsible for trade restrictions wherever they occur. Traps and “bait and kill stations” are important means of monitoring and control and Bob Heath made important contributions to these technologies....

  12. Biological control of the Mediterranean fruit fly in Israel: biological parameters of imported parasitoid wasps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three braconid species that parasitize the Mediterranean fruit fly (medfly), CERATITIS CAPITATA (Wiedemann) were recently imported into Israel. Several of their key biological parameters were studied. The longevities of the egg-attacking parasitoids FOPIUS ARISANUS and FOPIUS CERATITIVORUS, and t...

  13. Two new bee-killing flies from Brazil (Insecta: Diptera: Phoridae: Melaloncha)

    PubMed Central

    2016-01-01

    Abstract Background The genus Melaloncha is a large group of species of parasitoid phorid flies that attack Hymenoptera, mostly stingless bees (Meliponinae, Apidae) in the Neotropical Region. New information Two new Brazilian species, Melaloncha (Melaloncha) peacockorum sp. n. and Melaloncha (Udamochiras) nielsi sp. n., are described and their identification clarified. PMID:26929720

  14. Biological controls investigated to aid management of olive fruit fly in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recent widespread and rapid establishment of the olive fruit fly in California made necessary immediate changes in existing olive IPM programs. After determining that resident natural enemies (various generalist predators and a previously unknown parasitoid) that have been found attacking olive...

  15. Role of aluminous component of fly ash on the durability of Portland cement-fly ash pastes in marine environment.

    PubMed

    Lorenzo, Ma P; Goñi, S; Guerrero, A

    2003-01-01

    The durability, of mixtures of two kinds of Spanish fly ashes from coal combustion (ASTM class F) with 0, 15 and 35% replacement of Portland cement by fly ash, in a simulated marine environment (Na(2)SO(4)+NaCl solution of equivalent concentration to that of sea water: 0.03 and 0.45 M for sulphate and chloride, respectively), has been studied for a period of 90 days. The resistance of the different mixtures to the attack was evaluated by means of the Koch-Steinegger test. The results showed that all the mixtures were resistant, in spite of the great amount of Al(2)O(3) content of the fly ash. The diffusion of SO(4)(2-), Na+ and Cl- ions through the pore solution activated the pozzolanic reactivity of the fly ashes causing the corresponding microstructure changes, which were characterized by X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). As a result, the flexural strength of the mixtures increased, principally for the fly ash of a lower particle size and 35% of addition. PMID:14522197

  16. Role of aluminous component of fly ash on the durability of Portland cement-fly ash pastes in marine environment

    SciTech Connect

    Lorenzo, MaP.; Goni, S.; Guerrero, A

    2003-07-01

    The durability, of mixtures of two kinds of Spanish fly ashes from coal combustion (ASTM class F) with 0, 15 and 35% replacement of Portland cement by fly ash, in a simulated marine environment (Na{sub 2}SO{sub 4}+NaCl solution of equivalent concentration to that of sea water: 0.03 and 0.45 M for sulphate and chloride, respectively), has been studied for a period of 90 days. The resistance of the different mixtures to the attack was evaluated by means of the Koch-Steinegger test. The results showed that all the mixtures were resistant, in spite of the great amount of Al{sub 2}O{sub 3} content of the fly ash. The diffusion of SO{sub 4}{sup 2-}, Na{sup +} and Cl{sup -} ions through the pore solution activated the pozzolanic reactivity of the fly ashes causing the corresponding microstructure changes, which were characterized by X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). As a result, the flexural strength of the mixtures increased, principally for the fly ash of a lower particle size and 35% of addition.

  17. An annotated checklist of the horse flies, deer flies, and yellow flies (Diptera: Tabanidae) of Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The family Tabanidae includes the horse flies, deer flies, and yellow flies and is considered a significant pest of livestock throughout the United States, including Florida. Tabanids can easily become a major pest of man, especially salt marsh species which are known to readily feed on humans and o...

  18. Laboratory evaluation of novaluron for controlling larval horn flies, house flies, and stable flies (Diptera: Muscidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A granular formulation of novaluron (Novaluron 0.2G, 0.2% AI), a newer benzoylphenyl urea insecticide, was evaluated for its efficacy in controlling the larval stage of horn flies, Haematobia irritans (Linnaeus), house flies, Musca domestica Linnaeus, and stable flies, Stomoxys calcitrans (Linnaeus)...

  19. Generic attack approaches for industrial control systems.

    SciTech Connect

    Duggan, David P.

    2006-01-01

    This report suggests a generic set of attack approaches that are expected to be used against Industrial Control Systems that have been built according to a specific reference model for control systems. The posed attack approaches are ordered by the most desirable, based upon the goal of an attacker. Each attack approach is then graded by the category of adversary that would be capable of utilizing that attack approach. The goal of this report is to identify necessary levels of security required to prevent certain types of attacks against Industrial Control Systems.

  20. Test What You Fly?

    NASA Technical Reports Server (NTRS)

    Margolies, Don

    2002-01-01

    It was the first time on any NASA project I know of that all the instruments on an observatory came off for rework or calibration after the full range of environmental tests, and then were reintegrated at the launch center without the benefit of an observatory environmental retest. Perhaps you've heard the expression, 'Test what you fly, fly what you test'? In theory, it's hard to argue with that. In this case, I was willing to take the risk of not testing what I flew. As the project manager for the Advanced Composition Explorer (ACE) mission, I was the one who ultimately decided what risks to take, just as it was my responsibility to get buy-in from the stakeholders.

  1. Intermittent hypoendorphinaemia in migraine attack.

    PubMed

    Baldi, E; Salmon, S; Anselmi, B; Spillantini, M G; Cappelli, G; Brocchi, A; Sicuteri, F

    1982-06-01

    Beta-endorphin (RIA method, previous chromatographic extraction) was evaluated in plasma of migraine sufferers in free periods and during attacks. Decreased levels of the endogenous opioid peptide were found in plasma sampled during the attacks but not in free periods. Even chronic headache sufferers exhibited significantly lowered levels of beta-endorphin, when compared with control subjects with a negative personal and family history of head pains. The mechanism of the hypoendorphinaemia is unknown: lowered levels of the neuropeptide, which controls nociception, vegetative functions and hedonia, could be important in a syndrome such as migraine, characterized by pain, dysautonomia and anhedonia. The impairment of monoaminergic synapses ("empty neuron" condition) constantly present in sufferers from serious headaches, could be due to the fact that opioid neuropeptides, because of a receptoral or metabolic impairment, poorly modulate the respective monoaminergic neurons, resulting in imbalance of synaptic neurotransmission. PMID:6290072

  2. Lift and wakes of flying snakes

    NASA Astrophysics Data System (ADS)

    Krishnan, Anush; Socha, John J.; Vlachos, Pavlos P.; Barba, L. A.

    2014-03-01

    Flying snakes use a unique method of aerial locomotion: they jump from tree branches, flatten their bodies, and undulate through the air to produce a glide. The shape of their body cross-section during the glide plays an important role in generating lift. This paper presents a computational investigation of the aerodynamics of the cross-sectional shape. Two-dimensional simulations of incompressible flow past the anatomically correct cross-section of the species Chrysopelea paradisi show that a significant enhancement in lift appears at a 35° angle of attack, above Reynolds numbers 2000. Previous experiments on physical models also obtained an increased lift, at the same angle of attack. The flow is inherently three-dimensional in physical experiments, due to fluid instabilities, and it is thus intriguing that the enhanced lift also appears in the two-dimensional simulations. The simulations point to the lift enhancement arising from the early separation of the boundary layer on the dorsal surface of the snake profile, without stall. The separated shear layer rolls up and interacts with secondary vorticity in the near-wake, inducing the primary vortex to remain closer to the body and thus cause enhanced suction, resulting in higher lift.

  3. Diabetes - preventing heart attack and stroke

    MedlinePlus

    ... with diabetes have a higher chance of having heart attacks and strokes. Smoking and having high blood pressure ... and cholesterol levels are very important for preventing heart attacks and strokes. See your doctor who treats your ...

  4. After Heart Attack, New Threat: Heart Failure

    MedlinePlus

    ... of heart attack known as STEMI (ST elevation myocardial infarction). "Patients with ischemic heart disease are at the ... failure]. This includes those who have had a myocardial infarction, also called heart attack," Gho said. "Research studying ...

  5. Half of Heart Attacks Might Be 'Silent'

    MedlinePlus

    ... gov/medlineplus/news/fullstory_158855.html Half of Heart Attacks Might Be 'Silent' Without typical symptoms, many miss ... HealthDay News) -- As many as half of all heart attacks may be "silent" -- without the typical crushing chest ...

  6. Diabetes Ups Risk of Heart Attack Death

    MedlinePlus

    ... 159557.html Diabetes Ups Risk of Heart Attack Death Study points to need for better coordinated care, ... people with diabetes have a higher risk of death after a heart attack. "We knew that following ...

  7. Heart Attacks Striking Younger, Fatter Americans

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_157946.html Heart Attacks Striking Younger, Fatter Americans: Study Doctors, patients need ... 24, 2016 THURSDAY, March 24, 2016 (HealthDay News) -- Heart attack victims in the United States are becoming younger ...

  8. Diabetes Ups Risk of Heart Attack Death

    MedlinePlus

    ... news/fullstory_159557.html Diabetes Ups Risk of Heart Attack Death Study points to need for better coordinated ... are much more likely to die after a heart attack than people without the blood sugar condition, a ...

  9. Being active after a heart attack (image)

    MedlinePlus

    ... best activity when you start exercising after a heart attack. Start slowly, and increase the amount of time ... best activity when you start exercising after a heart attack. Start slowly, and increase the amount of time ...

  10. Fat May Not Hike Heart Attack Risk

    MedlinePlus

    ... news/fullstory_160179.html Fat May Not Hike Heart Attack Risk: Study But it does raise diabetes risk, ... that obesity may not increase the risk of heart attack or premature death. Their study of identical twins ...

  11. Diabetes - preventing heart attack and stroke

    MedlinePlus

    ... medlineplus.gov/ency/patientinstructions/000080.htm Diabetes - preventing heart attack and stroke To use the sharing features on ... with diabetes have a higher chance of having heart attacks and strokes. Smoking and having high blood pressure ...

  12. Half of Heart Attacks Might Be 'Silent'

    MedlinePlus

    ... medlineplus.gov/news/fullstory_158855.html Half of Heart Attacks Might Be 'Silent' Without typical symptoms, many miss ... HealthDay News) -- As many as half of all heart attacks may be "silent" -- without the typical crushing chest ...

  13. Fly-scan ptychography

    DOE PAGESBeta

    Huang, Xiaojing; Lauer, Kenneth; Clark, Jesse N.; Xu, Weihe; Nazaretski, Evgeny; Harder, Ross; Robinson, Ian K.; Chu, Yong S.

    2015-03-13

    We report an experimental ptychography measurement performed in fly-scan mode. With a visible-light laser source, we demonstrate a 5-fold reduction of data acquisition time. By including multiple mutually incoherent modes into the incident illumination, high quality images were successfully reconstructed from blurry diffraction patterns. This approach significantly increases the throughput of ptychography, especially for three-dimensional applications and the visualization of dynamic systems.

  14. Fly-scan ptychography

    PubMed Central

    Huang, Xiaojing; Lauer, Kenneth; Clark, Jesse N.; Xu, Weihe; Nazaretski, Evgeny; Harder, Ross; Robinson, Ian K.; Chu, Yong S.

    2015-01-01

    We report an experimental ptychography measurement performed in fly-scan mode. With a visible-light laser source, we demonstrate a 5-fold reduction of data acquisition time. By including multiple mutually incoherent modes into the incident illumination, high quality images were successfully reconstructed from blurry diffraction patterns. This approach significantly increases the throughput of ptychography, especially for three-dimensional applications and the visualization of dynamic systems. PMID:25766519

  15. On Mitigating Distributed Denial of Service Attacks

    ERIC Educational Resources Information Center

    Gao, Zhiqiang

    2006-01-01

    Denial of service (DoS) attacks and distributed denial of service (DDoS) attacks are probably the most ferocious threats in the Internet, resulting in tremendous economic and social implications/impacts on our daily lives that are increasingly depending on the well-being of the Internet. How to mitigate these attacks effectively and efficiently…

  16. Cyberprints: Identifying Cyber Attackers by Feature Analysis

    ERIC Educational Resources Information Center

    Blakely, Benjamin A.

    2012-01-01

    The problem of attributing cyber attacks is one of increasing importance. Without a solid method of demonstrating the origin of a cyber attack, any attempts to deter would-be cyber attackers are wasted. Existing methods of attribution make unfounded assumptions about the environment in which they will operate: omniscience (the ability to gather,…

  17. Predation on giant flying squirrels (Petaurista philippensis) by black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China.

    PubMed

    Fan, Peng-Fei; Jiang, Xue-Long

    2009-01-01

    Predation on vertebrates is infrequent in gibbons. In a 14-month field study of the central Yunnan black crested gibbon (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China, we observed gibbons attacking, killing and eating giant flying squirrels (Petaurista philippensis). During 845 h of observation on one study group, the gibbons attacked giant flying squirrels 11 times, and succeeded in 4 cases. Although all members of the group attempted to attack the squirrels, all four successful attacks were made by the same adult female. The victims were infants in three cases and a juvenile or sub-adult in one case. Black crested gibbons also attacked adult giant flying squirrels by grabbing their long tails and throwing them from the canopy, but they failed to catch or kill the prey in three cases observed. Passive meat sharing occurred in three out of four successful cases. Besides hunting giant flying squirrels, the black crested gibbons also ate eggs or chicks in two birds' nests and one lizard. PMID:19015936

  18. Free-Flight Evaluation of Forebody Blowing for Yaw Control at High Angels of Attack

    NASA Technical Reports Server (NTRS)

    Kiddy, Jason

    1995-01-01

    Forebody blowing is a concept developed to provide yaw control for aircraft flying at high angles of attack where a conventional rudder becomes ineffective. The basic concept is fairly simple. A small jet of air is forced out of the nose of the aircraft. This jet causes a repositioning of the forebody vortices in an asymmetrical fashion. The asymmetric forebody vortex flows develop a side force on the forebody which results in substantial yawing moments at high angles of attack. The purpose of this project was to demonstrate the use of forebody blowing as a control device through free-flight evaluation. This unique type of testing was performed at the NASA-Langley 30- by 60-foot tunnel. From these tests, it could then be shown that forebody blowing is an effective method of maintaining yaw control at high angles of attack.

  19. Deterioration of hardened cement paste under combined sulphate-chloride attack investigated by synchrotron XRD

    NASA Astrophysics Data System (ADS)

    Stroh, J.; Meng, B.; Emmerling, F.

    2016-06-01

    The exact mechanisms of the phase transitions caused by a combined sulphate-chloride attack are discussed controversially. The main points concern the mutual influences of sulphate and chloride ions during the secondary binding processes of these anions within cement hydrate phases. We simulated combined sulphate-chloride attack under laboratory conditions using solutions containing NaCl and Na2SO4 in different concentrations. Three sample compositions were used for the preparation of the specimens. In two of them, 30% of Portland cement was replaced by supplementary cementitious materials (fly ash, slag). The phase distribution in the samples was determined using synchrotron X-ray diffraction. The analysis with high spatial resolution allows the localisation of the secondary phase formation in the microstructural profile of the sample. A mechanism of the phase developments under combined sulphate-chloride attack is derived.

  20. The effect of the olive fruit fly (Bactrocera oleae) on quality parameters, and antioxidant and antibacterial activities of olive oil.

    PubMed

    Medjkouh, Lynda; Tamendjari, Abderezak; Keciri, Sonia; Santos, Joana; Nunes, M Antónia; Oliveira, M B P P

    2016-06-15

    The present study was performed on olives from two Algerian cultivars (Limli and Rougette de Metidja) with different rates of attack by the Bactrocera oleae fly (0%, not attacked; 100%, all attacked; and real attacked %) and the corresponding olive oils. The aim was to verify the attack effect on quality parameters (free fatty acid, peroxide value, K232 and K270, oxidation stability), bioactive compounds (fatty acids and tocopherols, and total phenols and flavonoids), and on the antioxidant (reducing power, FRAP, β-carotene bleaching inhibition, ABTS and DPPH) and antibacterial (against 8 referenced human enteropathogenic bacteria by the agar disc diffusion method) capacities. Oils from infested olives were downgraded to the virgin olive oil category. Rougette de Metidja, the cultivar with a higher drupe size, was more attacked than Limli. The B. oleae attack causes an important decrease in the total phenolic contents (>30%) but to a lesser degree in the case of tocopherols. Among them, α-tocopherol is the most affected. The antioxidant and antibacterial activities were highly correlated with phenolic levels. The results of this study show the importance of controlling the fly attack because it causes a decrease in the beneficial health effects of olive oils. PMID:27220688

  1. Auditory system of fruit flies.

    PubMed

    Ishikawa, Yuki; Kamikouchi, Azusa

    2016-08-01

    The fruit fly, Drosophila melanogaster, is an invaluable model for auditory research. Advantages of using the fruit fly include its stereotyped behavior in response to a particular sound, and the availability of molecular-genetic tools to manipulate gene expression and cellular activity. Although the receiver type in fruit flies differs from that in mammals, the auditory systems of mammals and fruit flies are strikingly similar with regard to the level of development, transduction mechanism, mechanical amplification, and central projections. These similarities strongly support the use of the fruit fly to study the general principles of acoustic information processing. In this review, we introduce acoustic communication and discuss recent advances in our understanding on hearing in fruit flies. This article is part of a Special Issue entitled . PMID:26560238

  2. Pest Control on the "Fly"

    NASA Technical Reports Server (NTRS)

    2002-01-01

    FlyCracker(R), a non-toxic and environmentally safe pesticide, can be used to treat and control fly problems in closed environments such as milking sheds, cattle barns and hutches, equine stables, swine pens, poultry plants, food-packing plants, and even restaurants, as well as in some outdoor animal husbandry environments. The product can be applied safely in the presence of animals and humans, and was recently permitted for use on organic farms as livestock production aids. FlyCracker's carbohydrate technology kills fly larvae within 24 hours. By killing larvae before they reach the adult stages, FlyCracker eradicates another potential breeding population. Because the process is physical-not chemical-flies and other insects never develop resistance to the treatment, giving way to unlimited use of product, while still keeping the same powerful effect.

  3. Courtship role reversal and deceptive signals in the long-tailed dance fly, Rhamphomyia longicauda.

    PubMed

    Funk; Tallamy

    2000-02-01

    We examined the function of secondary sexual characters in the role-reversed, lekking behaviour of female long-tailed dance flies, Rhamphomyia longicauda Loew (Empididae), to test the hypothesis that the degree of abdominal distention is an honest female signal about the state of egg development. Female Rhamphomyia cannot hunt for prey and they receive all of their protein from males by exchanging copulations for nuptial prey gifts. Females compete for male gifts within leks that are organized for a brief period each evening before dark. Before hovering within leks, females swallow air, inflating expandable pouches on the pleural margins of the abdomen. The result is a large saucer-like abdomen which is further exaggerated by wrapping scaled pro-, meso- and metathoracic legs along its pleural margins. Male preference for an enlarged abdomen was confirmed by suspending plastic models of varying size from monofilament lines and recording which models attracted the most males. There was a positive relationship between egg development and abdominal distention in a related species, R. sociabilis (Williston), which lacks inflatable abdominal pouches. Multiple regression showed that in R. longicauda, abdominal inflation completely masks the state of egg development. We conclude that female R. longicauda deceive mate-seeking males with the unreliable message that eggs are nearing maturation in order to obtain a protein meal in exchange for copulation. Males that fail to identify a female bearing mature eggs risk near-certain cuckoldry and an increased probability that the female will die before oviposition. Copyright 2000 The Association for the Study of Animal Behaviour. PMID:10675264

  4. Lightweight Distance Bounding Protocol against Relay Attacks

    NASA Astrophysics Data System (ADS)

    Kim, Jin Seok; Cho, Kookrae; Yum, Dae Hyun; Hong, Sung Je; Lee, Pil Joong

    Traditional authentication protocols are based on cryptographic techniques to achieve identity verification. Distance bounding protocols are an enhanced type of authentication protocol built upon both signal traversal time measurement and cryptographic techniques to accomplish distance verification as well as identity verification. A distance bounding protocol is usually designed to defend against the relay attack and the distance fraud attack. As there are applications to which the distance fraud attack is not a serious threat, we propose a streamlined distance bounding protocol that focuses on the relay attack. The proposed protocol is more efficient than previous protocols and has a low false acceptance rate under the relay attack.

  5. Blood feeding behavior of the stable fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stable fly is a fly that looks similar to a house fly but both sexes are blood feeders. Blood is required for successful fertilization and development of eggs. Bites are painful but there is usually no pain after the fly stops feeding. The stable fly is a persistent feeder and will continue trying t...

  6. The FlyBar: Administering Alcohol to Flies

    PubMed Central

    van der Linde, Kim; Fumagalli, Emiliano; Roman, Gregg; Lyons, Lisa C.

    2014-01-01

    Fruit flies (Drosophila melanogaster) are an established model for both alcohol research and circadian biology. Recently, we showed that the circadian clock modulates alcohol sensitivity, but not the formation of tolerance. Here, we describe our protocol in detail. Alcohol is administered to the flies using the FlyBar. In this setup, saturated alcohol vapor is mixed with humidified air in set proportions, and administered to the flies in four tubes simultaneously. Flies are reared under standardized conditions in order to minimize variation between the replicates. Three-day old flies of different genotypes or treatments are used for the experiments, preferably by matching flies of two different time points (e.g., CT 5 and CT 17) making direct comparisons possible. During the experiment, flies are exposed for 1 hr to the pre-determined percentage of alcohol vapor and the number of flies that exhibit the Loss of Righting reflex (LoRR) or sedation are counted every 5 min. The data can be analyzed using three different statistical approaches. The first is to determine the time at which 50% of the flies have lost their righting reflex and use an Analysis of the Variance (ANOVA) to determine whether significant differences exist between time points. The second is to determine the percentage flies that show LoRR after a specified number of minutes, followed by an ANOVA analysis. The last method is to analyze the whole times series using multivariate statistics. The protocol can also be used for non-circadian experiments or comparisons between genotypes. PMID:24895004

  7. Ameliorative effect of fly ashes

    SciTech Connect

    Bhumbla, D.K.

    1991-01-01

    Agronomic effectiveness and environmental impact of fly ashes used to reclaim pyritic acid mine spoils were investigated in the laboratory and field. Mine spoils at two abandoned sites were amended with three rates of fly ash, three rates of rock phosphate, and seeded with alfalfa and wheat. Application of fly ash decreased bulk density and increased moisture retention capacity of spoils. Fly ash application reduced cation exchange capacity, acidity, toxic levels of Al, Fe, and Mn in soils by buffering soil pH at 6.5, and retarded pyrite oxidation. The reduction in cation exchange capacity was compensated by release of plant nutrients through diffusion and dissolution of plerospheres in fly ash. Improvement of spoil physical, chemical and microbial properties resulted in higher yield, more nitrogen fixation, and utilization of P from rock phosphate by alfalfa. Laboratory investigations demonstrated that neutralization potential and the amounts of amorphous oxides of iron were more important for classifying fly ashes than the total elemental analysis presently used in a taxonomic classification system. Contamination of the food chain through plant removal of Mo and As in fly ash treated mine spoils was observed only for Mo and only for the first year of cropping. Plant available As and Mo decreased with time. Laboratory leaching and adsorption studies and a field experiment showed that trace metals do not leach from fly ashes at near neutral pH and more oxyanions will leach from fly ashes with low neutralization potential and low amounts of amorphous oxides of iron.

  8. X-31 Demonstrating High Angle of Attack - Herbst Maneuver

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The X-31 aircraft on a research mission from NASA's Dryden Flight Research Facility, Edwards, California, is flying nearly perpendicular to the flight path while performing the Herbst maneuver. Effectively using the entire airframe as a speed brake and using the aircraft's unique thrust vectoring system to maintain control, the pilot rapidly rolls the aircraft to reverse the direction of flight, completing the maneuver with acceleration back to high speed in the opposite direction. This type of turning capability could reduce the turning time of a fighter aircraft by 30 percent. The Herbst maneuver was first conducted in an X-31 on April 29, 1993, in the No. 2 aircraft by German test pilot Karl-Heinz Lang. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall

  9. A study of a three-dimensional self-propelled flying bird with flapping wings

    NASA Astrophysics Data System (ADS)

    Zhu, LinLin; Guan, Hui; Wu, ChuiJie

    2015-09-01

    In this paper, a study of a three-dimensional (3D) self-propelled bionic flying bird in a viscous flow is carried out. This bionic bird is propelled and lifted through flapping and rotating wings, and better flying can be achieved by adjusting the flapping and rotation motion of wings. In this study, we found that the bird can fly faster forward and upward with appropriate center of rotation and oscillation without more energy consumption and have perfect flight performance at a certain angle of attack by adjusting the center of oscillation. The study utilizes a 3D computational fluid dynamics package which constitutes combined immersed boundary method and the volume of fluid method. In addition, it includes adaptive multigrid finite volume method and control strategy of swimming and flying.

  10. Colony-level impacts of parasitoid flies on fire ants.

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

    The red imported fire ant is becoming a global ecological problem, having invaded the United States, Puerto Rico, New Zealand and, most recently, Australia. In its established areas, this pest is devastating natural biodiversity. Early attempts to halt fire ant expansion with pesticides actually enhanced its spread. Phorid fly parasitoids from South America have now been introduced into the United States as potential biological control agents of the red imported fire ant, but the impact of these flies on fire ant populations is currently unknown. In the laboratory, we show that an average phorid density of as little as one attacking fly per 200 foraging ants decreased colony protein consumption nearly twofold and significantly reduced numbers of large-sized workers 50 days later. The high impact of a single phorid occurred mainly because ants decreased foraging rates in the presence of the flies. Our experiments, the first (to our knowledge) to link indirect and direct effects of phorids on fire ants, demonstrate that colonies can be stressed with surprisingly low parasitoid densities. We interpret our findings with regard to the more complex fire ant-phorid interactions in the field. PMID:12204130

  11. NAVTOLAND and flying qualities

    NASA Technical Reports Server (NTRS)

    Momiyama, T. S.

    1977-01-01

    The V/STOL operational capability is reviewed with emphasis on pilot workload and all-weather landing guidance systems. A research and development program to correlate and integrate the development of all systems and techniques involved in enabling the pilot to fly V/STOL aircraft onto ships and tactical sites is described. Aircraft design parameters that affect its control in the vertical takeoff and landing flight regimes are emphasized. Topics considered include: (1) integrated flight controls and displays; (2) low speed sensor; (3) air traffic control appraoch and landing guidance systems; (4) visual landing aids; (5) ground effect induced thrust variation problems; and (6) handling qualities.

  12. Flying wires at Fermilab

    SciTech Connect

    Gannon, J.; Crawford, C.; Finley, D.; Flora, R.; Groves, T.; MacPherson, M.

    1989-03-01

    Transverse beam profile measurement systems called ''Flying Wires'' have been installed and made operational in the Fermilab Main Ring and Tevatron accelerators. These devices are used routinely to measure the emittance of both protons and antiprotons throughout the fill process, and for emittance growth measurements during stores. In the Tevatron, the individual transverse profiles of six proton and six antiproton bunches are obtained simultaneously, with a single pass of the wire through the beam. Essential features of the hardware, software, and system operation are explained in the rest of the paper. 3 refs., 4 figs.

  13. [Otorhinolaryngologic diseases and flying].

    PubMed

    Moser, M

    2002-01-01

    Physiological and pathological aspects of pressure changes, noise, acceleration, variation of temperature, low humidity, stress and time differences in flight passengers and aircrew are discussed. Typical ear, nose, and throat clinic (ENT)-cases such as tubal function disturbances, barotrauma, hypacusis, sudden hearing loss, tinnitus, acute and chronic middle ear diseases, post ear surgery conditions, hearing aids, vertigo and motion sickness are described. The influence on flying of acute and chronic affections of the paranasal sinuses, nasal septal deviation and allergy are listed. The problem of transport of ENT-incapacitated passengers in commercial aircrafts and ambulance jets are dealt with. PMID:12385068

  14. Flying over decades

    NASA Astrophysics Data System (ADS)

    Hoeller, Judith; Issler, Mena; Imamoglu, Atac

    Levy flights haven been extensively used in the past three decades to describe non-Brownian motion of particles. In this presentation I give an overview on how Levy flights have been used across several disciplines, ranging from biology to finance to physics. In our publication we describe how a single electron spin 'flies' when captured in quantum dot using the central spin model. At last I motivate the use of Levy flights for the description of anomalous diffusion in modern experiments, concretely to describe the lifetimes of quasi-particles in Josephson junctions. Finished PhD at ETH in Spring 2015.

  15. Flying by Titan

    NASA Technical Reports Server (NTRS)

    Pelletier, Frederic J.; Antreasian, Peter G.; Ardalan, Shadan M.; Criddle, Kevin E.; Ionasescu, Rodica; Jacobson, Robert A.; Jones, Jeremy B.; Parcher, Daniel W.; Roth, Duane C.; Thompson, Paul F.; Vaughan, Andrew T.

    2008-01-01

    The Cassini spacecraft encounters the massive Titan about once every month. These encounters are essential to the mission as Titan is the only satellite of Saturn that can provide enough gravity assist to shape the orbit tour and allow outstanding science for many years. From a navigation point of view, these encounters provide many challenges, in particular those that fly close enough to the surface for the atmospheric drag to perturb the orbit. This paper discusses the dynamics models developed to successfully navigate Cassini and determine its trajectory. This includes the moon's gravity pull with its second degree zonal harmonics J2, the attitude thrust control perturbations and the acceleration of drag.

  16. Flying in, Flying out: Offshore Teaching in Higher Education

    ERIC Educational Resources Information Center

    Seah, Wee Tiong; Edwards, Julie

    2006-01-01

    This paper discusses the relatively new phenomenon of university education faculties offering offshore education. The analogy, "flying in, flying out" captures the intensity of such offshore experiences for visiting academics, and contrasts their professional experiences against expatriate academics. This paper reports on case studies of two…

  17. Flying qualities design criteria applicable to supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Chalk, C. R.

    1980-01-01

    A comprehensive set of flying qualities design criteria was prepared for use in the supersonic cruise research program. The framework for stating the design criteria is established and design criteria are included which address specific failures, approach to dangerous flight conditions, flight at high angle of attack, longitudinal and lateral directional stability and control, the primary flight control system, and secondary flight controls. Examples are given of lateral directional design criteria limiting lateral accelerations at the cockpit, time to roll through 30 deg of bank, and time delay in the pilot's command path. Flight test data from the Concorde certification program are used to substantiate a number of the proposed design criteria.

  18. Fly ash quality and utilization

    SciTech Connect

    Barta, L.E.; Lachner, L.; Wenzel, G.B.; Beer, M.J.

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  19. Migraine attacks the Basal Ganglia

    PubMed Central

    2011-01-01

    Background With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month). The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human) brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF) to a matched (gender, age, age of onset and type of medication) group of patients whose migraine episodes progressed (HF). Results In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain. Conclusions Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine. PMID:21936901

  20. Shoulder injuries from attacking motion

    NASA Astrophysics Data System (ADS)

    Yanagi, Shigeru; Nishimura, Tetsu; Itoh, Masaru; Wada, Yuhei; Watanabe, Naoki

    1997-03-01

    Sports injuries have bothered professional players. Although many medical doctors try to treat injured players, to prevent sports injuries is more important. Hence, it is required to clear a kinematic mechanism of the sport injuries. A shoulder of volleyball attacker or baseball pitcher is often inured by playing motion. The injuries are mainly caused at the end of long head tendon, which is located in the upper side of scapula. Generally, a muscle and tendon have enough strength against tensile force, however, it seems that they are sometimes defeated by the lateral force. It is imagined that the effect of the lateral force has a possibility of injuring the tendon. If we find the influence of the lateral force on the injured portion, the mechanism of injuries must be cleared. In our research, volleyball attacking motion is taken by high speed video cameras. We analyze the motion as links system and obtain an acceleration of an arm and a shoulder from video image data. The generated force at a shoulder joint is calculated and resolved into the lateral and longitudinal forces. Our final goal is to discuss a possibility that the lateral force causes the injuries.

  1. The Flying University

    NASA Astrophysics Data System (ADS)

    Friesen, Catherine

    The Flying University is solo theater performance framed as an academic lecture about Marie Curie and her discovery of radium, delivered to a group of women who have gathered in secret to further their education. As the lecture proceeds, the professor brings in her own research based on a study of Esther Horsch (1905-1991) who lived on a farm in central Illinois. She introduces data from Esther's journals, personal memories, and dreams about Esther's life. The professor's investigation of radium plays at the intersections of magical and mundane, decay and the transformation of life, and the place of ambition in these two women's lives. The intention of this piece is to explore these themes, which are full of mystery, through the traces of the daily lives of Mme. Curie and Esther. Their words and photos are used as roots from which to imagine the things that echo beyond their familiar work; elemental and also fantastically radiant. The Flying University was written and performed by Catherine Friesen April 27-29, 2012 in the Center for Performance Experiment at Hamilton College as part of the University of South Carolina MFA Acting Class of 2013 showcase, Pieces of Eight.

  2. Flies, clocks and evolution.

    PubMed Central

    Rosato, E; Kyriacou, C P

    2001-01-01

    The negative feedback model for gene regulation of the circadian mechanism is described for the fruitfly, Drosophila melanogaster. The conservation of function of clock molecules is illustrated by comparison with the mammalian circadian system, and the apparent swapping of roles between various canonical clock gene components is highlighted. The role of clock gene duplications and divergence of function is introduced via the timeless gene. The impressive similarities in clock gene regulation between flies and mammals could suggest that variation between more closely related species within insects might be minimal. However, this is not borne out because the expression of clock molecules in the brain of the giant silk moth, Antheraea pernyi, is not easy to reconcile with the negative feedback roles of the period and timeless genes. Variation in clock gene sequences between and within fly species is examined and the role of co-evolution between and within clock molecules is described, particularly with reference to adaptive functions of the circadian phenotype. PMID:11710984

  3. Physics of flying

    NASA Astrophysics Data System (ADS)

    Vetrone, Jim

    2015-05-01

    Column editor's note: As the school year comes to a close, it is important to start thinking about next year. One area that you want to consider is field trips. Many institutions require that teachers plan for a field trip well in advance. Keeping that in mind, I asked Jim Vetrone to write an article about the fantastic field trip he takes his AP Physics students on. I had the awesome opportunity to attend a professional development day that Jim arranged at iFLY in the Chicago suburbs. The experience of "flying" in a wind tunnel was fabulous. Equally fun was watching the other physics teachers come up with experiments to have the professional "flyers" perform in the tube. I could envision my students being similarly excited about the experience and about the development of their own experiments. After I returned to school, I immediately began the process of trying to get this field trip approved for the 2015-16 school year. I suggest that you start your process as well if you hope to try a new field trip next year. The key to getting the approval, in my experience, is submitting a proposal early that includes supporting documentation from sources. Often I use NGSS or state standards as justifications for my field trips. I have also quoted College Board expectations for AP Physics 1 and 2 in my documents when requesting an unusual field trip.

  4. Why flies are good vectors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It was around 1900 when house flies were implicated in disease transmission. Flies with white powder on their feet were seen landing on food in US Army chow halls. This white powder was lime that had been sprinkled over the human excrement in open latrines not too far from the eating establishments....

  5. Passive Baited Sequential Fly Trap

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sampling fly populations associated with human populations is needed to understand diel behavior and to monitor population densities before and after control operations. Population control measures are dependent on the results of monitoring efforts as they may provide insight into the fly behavior ...

  6. Percolation of localized attack on complex networks

    NASA Astrophysics Data System (ADS)

    Shao, Shuai; Huang, Xuqing; Stanley, H. Eugene; Havlin, Shlomo

    2015-02-01

    The robustness of complex networks against node failure and malicious attack has been of interest for decades, while most of the research has focused on random attack or hub-targeted attack. In many real-world scenarios, however, attacks are neither random nor hub-targeted, but localized, where a group of neighboring nodes in a network are attacked and fail. In this paper we develop a percolation framework to analytically and numerically study the robustness of complex networks against such localized attack. In particular, we investigate this robustness in Erdős-Rényi networks, random-regular networks, and scale-free networks. Our results provide insight into how to better protect networks, enhance cybersecurity, and facilitate the design of more robust infrastructures.

  7. Impact of imperfect information on network attack

    NASA Astrophysics Data System (ADS)

    Melchionna, Andrew; Caloca, Jesus; Squires, Shane; Antonsen, Thomas M.; Ott, Edward; Girvan, Michelle

    2015-03-01

    This paper explores the effectiveness of network attack when the attacker has imperfect information about the network. For Erdős-Rényi networks, we observe that dynamical importance and betweenness centrality-based attacks are surprisingly robust to the presence of a moderate amount of imperfect information and are more effective compared with simpler degree-based attacks even at moderate levels of network information error. In contrast, for scale-free networks the effectiveness of attack is much less degraded by a moderate level of information error. Furthermore, in the Erdős-Rényi case the effectiveness of network attack is much more degraded by missing links as compared with the same number of false links.

  8. Impact of imperfect information on network attack.

    PubMed

    Melchionna, Andrew; Caloca, Jesus; Squires, Shane; Antonsen, Thomas M; Ott, Edward; Girvan, Michelle

    2015-03-01

    This paper explores the effectiveness of network attack when the attacker has imperfect information about the network. For Erdős-Rényi networks, we observe that dynamical importance and betweenness centrality-based attacks are surprisingly robust to the presence of a moderate amount of imperfect information and are more effective compared with simpler degree-based attacks even at moderate levels of network information error. In contrast, for scale-free networks the effectiveness of attack is much less degraded by a moderate level of information error. Furthermore, in the Erdős-Rényi case the effectiveness of network attack is much more degraded by missing links as compared with the same number of false links. PMID:25871157

  9. The flying radiation case

    SciTech Connect

    Brownell, J.H.; Bowers, R.L.

    1997-04-01

    The Los Alamos foil implosion program has the goal of producing an intense, high-energy density x-ray source by converting the energy of a magnetically imploded plasma into radiation and material energy. One of the methods for converting the plasma energy into thermal energy and radiation and utilizing it for experiments is called the flying radiation case (FRC). In this paper the authors shall model the FRC and provide a physical description of the processes involved. An analytic model of a planar FRC in the hydrodynamic approximation is used to describe the assembly and shock heating of a central cushion by a conducting liner driver. The results are also used to benchmark a hydrodynamics code for modeling an FRC. They then use a radiation-hydrodynamics computational model to explore the effects of radiation production and transport when a gold plasma assembles on a CH cushion. Results are presented for the structure and evolution of the radiation hohlraum.

  10. Detecting Denial of Service Attacks in Tor

    NASA Astrophysics Data System (ADS)

    Danner, Norman; Krizanc, Danny; Liberatore, Marc

    Tor is currently one of the more popular systems for anonymizing near real-time communications on the Internet. Recently, Borisov et al. proposed a denial of service based attack on Tor (and related systems) that significantly increases the probability of compromising the anonymity provided. In this paper, we propose an algorithm for detecting such attacks and examine the effectiveness of the obvious approach to evading such detection. We implement a simplified version of the detection algorithm and study whether the attack may be in progress on the current Tor network. Our preliminary measurements indicate that the attack was probably not implemented during the period we observed the network.

  11. High angle of attack control law development for a free-flight wind tunnel model using direct eigenstructure assignment

    NASA Technical Reports Server (NTRS)

    Wendel, Thomas R.; Boland, Joseph R.; Hahne, David E.

    1991-01-01

    Flight-control laws are developed for a wind-tunnel aircraft model flying at a high angle of attack by using a synthesis technique called direct eigenstructure assignment. The method employs flight guidelines and control-power constraints to develop the control laws, and gain schedules and nonlinear feedback compensation provide a framework for considering the nonlinear nature of the attack angle. Linear and nonlinear evaluations show that the control laws are effective, a conclusion that is further confirmed by a scale model used for free-flight testing.

  12. Transcript Profiles of Two Wheat Lipid Transfer Protein-encoding Genes are Altered During Attach by Hessian Fly Larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘GeneCalling’, an mRNA profiling technology, was used to identify a candidate lipid transfer protein (LTP) sequence that showed decreased mRNA abundance in wheat (Triticum aestivum L. em Thell) plants following attack by virulent Hessian fly (Mayetiola destructor Say) larvae (compatible interaction)...

  13. Establishment of the west indian fruit fly (Diptera: Tephritidae) parasitoid Doryctobracon areolatus (Hymenoptera: Braconidae)in the Dominican Republic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The West Indian fruit fly, Anastrepha obliqua (Macquart), infests numerous fruit species, particularly Anacardiaceae and most importantly mango (Mangifera indica L.). Widespread in the Neotropics, it was first reported in Hispaniola nearly 70 years ago. Continental populations are attacked by the op...

  14. Sorptivity of fly ash concretes

    SciTech Connect

    Gopalan, M.K.

    1996-08-01

    A factorial experiment was designed to measure the sorptivity of cement and fly ash concretes in order to compare the durability of fly ash concrete against the cement concrete. Sorptivity measurements based on the capillary movement of water was made on three grades of cement concrete and six grades of fly ash mixes. The effect of curing was also studied by treating the samples in two curving conditions. A functional relationship of sorptivity against the strength, curing condition and fly ash content has been presented. The results were useful to analyze the factors influencing the durability of cement and fly ash concretes and to explain why some of the previously reported findings were contradictory. Curing conditions have been found to be the most important factor that affected the durability properties of fly ash concrete. When proper curing was provided, a mix with 40% fly ash was found to reduce the sorptivity by 37%. Under inadequate curing the sorptivity was found to increase by 60%. The influence of curing on cement concrete was found to be of much less importance.

  15. Driving under the influence (of stress): evidence of a regional increase in impaired driving and traffic fatalities after the september 11 terrorist attacks.

    PubMed

    Su, Jenny C; Tran, Alisia G T T; Wirtz, John G; Langteau, Rita A; Rothman, Alexander J

    2009-01-01

    Did the September 11 terrorist attacks elicit a subsequent increase in traffic fatalities? Gigerenzer (2004) argued that decreases in flying and increases in driving in the 3 months after the attacks led to 353 "surplus" traffic fatalities. We applied a more systematic analysis to the same data and found no evidence of a significant increase in miles driven or of a significant increase in traffic fatalities. However, we did find evidence for a regional effect of the attacks on driving behaviors. We hypothesized that geographic proximity to the attacks increased stress, which in turn decreased driving quality. Our analyses revealed that in the last 3 months of 2001, the Northeast exhibited a significant increase in traffic fatalities, as well as a significant increase in fatal accidents involving an alcohol- or drug-related citation. Increased stress related to physical proximity to the attacks may explain the increase in traffic fatalities. PMID:19152541

  16. Alkali ash material: a novel fly ash-based cement.

    PubMed

    Rostami, Hossein; Brendley, William

    2003-08-01

    The United States generates 110 million t of coal ash annually. Approximately 70 million t of this coal ash is fly ash, of which 27% is recycled and the remaining 73% is landfilled. Disposal of such a huge quantity of ash poses a significant environmental problem. A new cementitious material has been developed, called alkali ash material (AAM), which is used to produce concrete for construction. AAM can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economic advantage. AAM contains 40-95% Class F fly ash and is used as cement to bind sand, stone, and fibers creating concrete. AAM concrete has been tested for strength, durability, mechanical properties, and, most importantly, economic viability. AAM concrete is economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of ultimate in 1 d), high ultimate strengths (110 MPa or 16,000 psi in 1 d), excellent acid resistance, and freeze-thaw durability. AAM's resistance to chemical attack, such as sulfuric (H2SO4), nitric (HNO3), hydrochloric (HCl), and organic acids, is far better than portland cement concrete. AAM is resistant to freeze-thaw attack based on ASTM C-666 specifications. Potential immediate applications of AAM are blocks, pipe, median barriers, sound barriers, and overlaying materials. Eventual markets are high strength construction products, bridge beams, prestressed members, concrete tanks, highway appurtenances, and other concrete products. PMID:12966995

  17. Terrorist attacks escalate in frequency and fatalities preceding highly lethal attacks.

    PubMed

    Martens, Andy; Sainudiin, Raazesh; Sibley, Chris G; Schimel, Jeff; Webber, David

    2014-01-01

    Highly lethal terrorist attacks, which we define as those killing 21 or more people, account for 50% of the total number of people killed in all terrorist attacks combined, yet comprise only 3.5% of terrorist attacks. Given the disproportionate influence of these incidents, uncovering systematic patterns in attacks that precede and anticipate these highly lethal attacks may be of value for understanding attacks that exact a heavy toll on life. Here we examined whether the activity of terrorist groups escalates--both in the number of people killed per attack and in the frequency of attacks--leading up to highly lethal attacks. Analyses of terrorist attacks drawn from a state-of-the-art international terrorism database (The Global Terrorism Database) showed evidence for both types of escalation leading up to highly lethal attacks, though complexities to the patterns emerged as well. These patterns of escalation do not emerge among terrorist groups that never commit a highly lethal attack. PMID:24755753

  18. The cost of attack in competing networks.

    PubMed

    Podobnik, B; Horvatic, D; Lipic, T; Perc, M; Buldú, J M; Stanley, H E

    2015-11-01

    Real-world attacks can be interpreted as the result of competitive interactions between networks, ranging from predator-prey networks to networks of countries under economic sanctions. Although the purpose of an attack is to damage a target network, it also curtails the ability of the attacker, which must choose the duration and magnitude of an attack to avoid negative impacts on its own functioning. Nevertheless, despite the large number of studies on interconnected networks, the consequences of initiating an attack have never been studied. Here, we address this issue by introducing a model of network competition where a resilient network is willing to partially weaken its own resilience in order to more severely damage a less resilient competitor. The attacking network can take over the competitor's nodes after their long inactivity. However, owing to a feedback mechanism the takeovers weaken the resilience of the attacking network. We define a conservation law that relates the feedback mechanism to the resilience dynamics for two competing networks. Within this formalism, we determine the cost and optimal duration of an attack, allowing a network to evaluate the risk of initiating hostilities. PMID:26490628

  19. Preventive attack in the 1990s

    SciTech Connect

    Prebeck, S.R.

    1993-05-28

    The decline of the Soviet Union upset the world`s balance of power and opened the door to third world proliferation since the superpowers no longer have tight control over their client-states. This increase in proliferation raised the issue of how the United States (US) should respond to a third world nation that is acquiring nuclear weapons. Should the United States depend on preventive attacks to stop the proliferation of nuclear weapons. This is not a new issue. Proliferation and preventive war have both been issues since the end of World War II. The United States considered a preventive attack against the Soviet Union in the postwar years. The Soviet Union considered preventive attacks against the People`s Republic of China in 1969. Israel conducted a preventive attack in 1981 against the Osiraq nuclear reactor in Iraq. Preventive attacks are politically untenable and are not militarily possible. Without perfect political conditions, it is unacceptable for the only remaining superpower to attack a second-rate power. It is militarily impossible for the United States to guarantee the removal of all nuclear weapons in a single preventive attack. This study concludes that the United States should not depend on preventive attacks to stop proliferation of nuclear weapons.

  20. 47 CFR 76.1612 - Personal attack.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Personal attack. 76.1612 Section 76.1612 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Notices § 76.1612 Personal attack. (a) When, during origination cablecasting...

  1. Molecular Studies of Fly-Borne Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vector-borne diseases are among the most significant threats to agriculture and human health. Mosquitoes are the most significant vectors of disease, but other biting and blood feeding flies such as black flies (Simuliidae), keds (Hippoboscidae), bot flies (Oestridae), and stable flies (Muscidae) a...

  2. Combating Memory Corruption Attacks On Scada Devices

    NASA Astrophysics Data System (ADS)

    Bellettini, Carlo; Rrushi, Julian

    Memory corruption attacks on SCADA devices can cause significant disruptions to control systems and the industrial processes they operate. However, despite the presence of numerous memory corruption vulnerabilities, few, if any, techniques have been proposed for addressing the vulnerabilities or for combating memory corruption attacks. This paper describes a technique for defending against memory corruption attacks by enforcing logical boundaries between potentially hostile data and safe data in protected processes. The technique encrypts all input data using random keys; the encrypted data is stored in main memory and is decrypted according to the principle of least privilege just before it is processed by the CPU. The defensive technique affects the precision with which attackers can corrupt control data and pure data, protecting against code injection and arc injection attacks, and alleviating problems posed by the incomparability of mitigation techniques. An experimental evaluation involving the popular Modbus protocol demonstrates the feasibility and efficiency of the defensive technique.

  3. Dewatered sewage biosolids provide a productive larval habitat for stable flies and house flies (Diptera: Muscidae).

    PubMed

    Doud, C W; Taylor, D B; Zurek, L

    2012-03-01

    Species diversity and seasonal abundance of muscoid flies (Diptera: Muscidae) developing in biosolid cake (dewatered biosolids) stored at a wastewater treatment facility in northeastern Kansas were evaluated. Emergence traps were deployed 19 May through 20 October 2009 (22 wk) and 27 May through 18 November 2010 (25 wk). In total, 11,349 muscoid flies were collected emerging from the biosolid cake. Stable flies (Stomoxys calcitrans (L.)) and house flies (Musca domestica (L.)), represented 80 and 18% of the muscoid flies, respectively. An estimated 550 stable flies and 220 house flies per square-meter of surface area developed in the biosolid cake annually producing 450,000 stable flies and 175,000 house flies. Stable fly emergence was seasonally bimodal with a primary peak in mid-July and a secondary peak in late August. House fly emergence peaked with the first stable fly emergence peak and then declined gradually for the remainder of the year. House flies tended to emerge from the biosolid cake sooner after its deposition than did stable flies. In addition, house fly emergence was concentrated around midsummer whereas stable fly emergence began earlier in the spring and continued later into the fall. Biosolid age and temperature were the most important parameters affecting emergence for house flies and stable flies, whereas precipitation was not important for either species. This study highlights the importance of biosolid cake as a larval developmental habitat for stable flies and house flies. PMID:22493845

  4. Subtropical Fruit Fly Invasions into Temperate Fruit Fly Territory in California's San Joaquin Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subtropical fruit fly species including peach fruit fly, Bactrocera zonata (Saunders); melon fly, B. cucurbitae (Coquillett); oriental fruit fly, B. dorsalis (Hendel); and Mediterranean fruit fly, Ceratitis capitata Weidemann, have been detected in the past decade in the San Joaquin Valley of Califo...

  5. Managing the Fruit Fly Experiment.

    ERIC Educational Resources Information Center

    Jeszenszky, Arleen W.

    1997-01-01

    Describes a sophisticated version of the fruit fly experiment for teaching concepts about genetics to biology students. Provides students with the opportunity to work with live animals over an extended period. (JRH)

  6. Symptoms of transient ischemic attack.

    PubMed

    Kim, Jong S

    2014-01-01

    Transient ischemic attack (TIA) is a cerebrovascular disease with temporary (<24 h) neurological symptoms. The symptoms of TIA patients are largely similar to those of ischemic stroke patients and include unilateral limb weakness, speech disturbances, sensory symptoms, visual disturbances, and gait difficulties. As these symptoms are transient, they are frequently evaluated based on patients' subjective reports, which are less precise than those of patients with stroke whose longer-lasting symptoms and signs can be reliably assessed by physicians. Some symptoms, such as monocular blindness, are much more common in TIA than in stroke, and limb shaking occurs almost exclusively in TIA patients. On the other hand, symptoms like hemivisual field defects or limb ataxia are underappreciated in TIA patients. These transient neurological symptoms are not necessarily caused by cerebrovascular diseases, but can be produced by a variety of non-vascular diseases. Careful history taking, examination, and appropriate imaging tests are needed to differentiate these TIA mimics from TIA. Each TIA symptom has a different specificity and sensitivity, and there has been an effort to assess the outcome of the patients through the use of specific clinical features. On top of this, recent developments in imaging techniques have greatly enhanced our ability to predict the outcomes of TIA patients. Perception or recognition of TIA symptoms may differ according to the race, sex, education, and specialty of physicians. Appropriate education of both the general population and physicians with regard to TIA symptoms is important as TIAs need emergent evaluation and treatment. PMID:24157558

  7. Accident Flying Squad

    PubMed Central

    Snook, Roger

    1972-01-01

    This paper describes the organization, evaluation, and costing of an independently financed and operated accident flying squad. 132 accidents involving 302 casualties were attended, six deaths were prevented, medical treatment contributed to the survival of a further four, and the condition or comfort of many other casualties was improved. The calls in which survival was influenced were evenly distributed throughout the three-and-a-half-year survey and seven of the 10 so aided were over 16 and under 30 years of age, all 10 being in the working age group. The time taken to provide the service was not excessive and the expense when compared with the overall saving was very small. The scheme was seen to be equally suitable for basing on hospital or general practice or both, and working as an integrated team with the ambulance service. The use of specialized transport was found to be unnecessary. Other benefits of the scheme included use of the experience of attending accidents to ensure relevant and realistic training for emergency service personnel, and an appreciation of the effect of ambulance design on the patient. ImagesFIG. 1FIG. 4 PMID:5069642

  8. Trophic interactions between parasitoids and necrophagous flies in Central Argentina.

    PubMed

    Sereno, Ana P; Salvo, Adriana; Battán-Horenstein, Moira

    2016-10-01

    Larvae of necrophagous flies in the families Calliphoridae, Sarcophagidae and Muscidae are the main exploiters of decaying organic matter. Knowledge of insect species associated with each stage of decay can be used to estimate the time since death in the crime scene. Dipteran larvae are attacked by a rich community of parasitoids, including species of Braconidae, Ichneumonidae and Pteromalidae (Hymenoptera: Parasitica). This study examined the parasitic complex associated with flies of forensic and sanitary importance in the city of Córdoba (Argentina). Sampling was conducted at two sites with different urbanization levels from December 2012 to March 2013; parasitoids were collected using fly traps baited with beef liver. Rates of parasitism and of parasitized pupae were estimated and species composition was analyzed for both communities. Sarcophagidae was the most abundant family, represented by two species, followed by Calliphoridae. Nasonia vitripennis Ashmead (Hymenoptera) was the most abundant species and was collected from a wider variety of hosts. To the best of our knowledge, this is the first study providing accurate information about trophic interactions between calyptrate dipteran species and their hymenopteran parasitoids in central Argentina. PMID:27423397

  9. Terrorist Attacks Escalate in Frequency and Fatalities Preceding Highly Lethal Attacks

    PubMed Central

    Martens, Andy; Sainudiin, Raazesh; Sibley, Chris G.; Schimel, Jeff; Webber, David

    2014-01-01

    Highly lethal terrorist attacks, which we define as those killing 21 or more people, account for 50% of the total number of people killed in all terrorist attacks combined, yet comprise only 3.5% of terrorist attacks. Given the disproportionate influence of these incidents, uncovering systematic patterns in attacks that precede and anticipate these highly lethal attacks may be of value for understanding attacks that exact a heavy toll on life. Here we examined whether the activity of terrorist groups escalates–both in the number of people killed per attack and in the frequency of attacks–leading up to highly lethal attacks. Analyses of terrorist attacks drawn from a state-of-the-art international terrorism database (The Global Terrorism Database) showed evidence for both types of escalation leading up to highly lethal attacks, though complexities to the patterns emerged as well. These patterns of escalation do not emerge among terrorist groups that never commit a highly lethal attack. PMID:24755753

  10. Hill-Climbing Attacks and Robust Online Signature Verification Algorithm against Hill-Climbing Attacks

    NASA Astrophysics Data System (ADS)

    Muramatsu, Daigo

    Attacks using hill-climbing methods have been reported as a vulnerability of biometric authentication systems. In this paper, we propose a robust online signature verification algorithm against such attacks. Specifically, the attack considered in this paper is a hill-climbing forged data attack. Artificial forgeries are generated offline by using the hill-climbing method, and the forgeries are input to a target system to be attacked. In this paper, we analyze the menace of hill-climbing forged data attacks using six types of hill-climbing forged data and propose a robust algorithm by incorporating the hill-climbing method into an online signature verification algorithm. Experiments to evaluate the proposed system were performed using a public online signature database. The proposed algorithm showed improved performance against this kind of attack.

  11. Zebras and Biting Flies: Quantitative Analysis of Reflected Light from Zebra Coats in Their Natural Habitat.

    PubMed

    Britten, Kenneth H; Thatcher, Timothy D; Caro, Tim

    2016-01-01

    Experimental and comparative evidence suggests that the striped coats of zebras deter biting fly attack, but the mechanisms by which flies fail to target black-and-white mammals are still opaque. Two hypotheses have been proposed: stripes might serve either to defeat polarotaxis or to obscure the form of the animal. To test these hypotheses, we systematically photographed free-living plains zebras in Africa. We found that black and white stripes both have moderate polarization signatures with a similar angle, though the degree (magnitude) of polarization in white stripes is lower. When we modeled the visibility of these signals from different distances, we found that polarization differences between stripes are invisible to flies more than 10 m away because they are averaged out by the flies' low visual resolution. At any distance, however, a positively polarotactic insect would have a distinct signal to guide its visual approach to a zebra because we found that polarization of light reflecting from zebras is higher than from surrounding dry grasses. We also found that the stripes themselves are visible to flies at somewhat greater distances (up to 20 m) than the polarization contrast between stripes. Together, these observations support hypotheses in which zebra stripes defeat visually guided orienting behavior in flies by a mechanism independent of polarotaxis. PMID:27223616

  12. Adaptive cyber-attack modeling system

    NASA Astrophysics Data System (ADS)

    Gonsalves, Paul G.; Dougherty, Edward T.

    2006-05-01

    The pervasiveness of software and networked information systems is evident across a broad spectrum of business and government sectors. Such reliance provides an ample opportunity not only for the nefarious exploits of lone wolf computer hackers, but for more systematic software attacks from organized entities. Much effort and focus has been placed on preventing and ameliorating network and OS attacks, a concomitant emphasis is required to address protection of mission critical software. Typical software protection technique and methodology evaluation and verification and validation (V&V) involves the use of a team of subject matter experts (SMEs) to mimic potential attackers or hackers. This manpower intensive, time-consuming, and potentially cost-prohibitive approach is not amenable to performing the necessary multiple non-subjective analyses required to support quantifying software protection levels. To facilitate the evaluation and V&V of software protection solutions, we have designed and developed a prototype adaptive cyber attack modeling system. Our approach integrates an off-line mechanism for rapid construction of Bayesian belief network (BN) attack models with an on-line model instantiation, adaptation and knowledge acquisition scheme. Off-line model construction is supported via a knowledge elicitation approach for identifying key domain requirements and a process for translating these requirements into a library of BN-based cyber-attack models. On-line attack modeling and knowledge acquisition is supported via BN evidence propagation and model parameter learning.

  13. Smart Grid Integrity Attacks: Characterizations and Countermeasures

    SciTech Connect

    Annarita Giani; Eilyan Bitar; Miles McQueen; Pramod Khargonekar; Kameshwar Poolla

    2011-10-01

    Real power injections at loads and generators, and real power flows on selected lines in a transmission network are monitored, transmitted over a SCADA network to the system operator, and used in state estimation algorithms to make dispatch, re-balance and other energy management system [EMS] decisions. Coordinated cyber attacks of power meter readings can be arranged to be undetectable by any bad data detection algorithm. These unobservable attacks present a serious threat to grid operations. Of particular interest are sparse attacks that involve the compromise of a modest number of meter readings. An efficient algorithm to find all unobservable attacks [under standard DC load flow approximations] involving the compromise of exactly two power injection meters and an arbitrary number of power meters on lines is presented. This requires O(n2m) flops for a power system with n buses and m line meters. If all lines are metered, there exist canonical forms that characterize all 3, 4, and 5-sparse unobservable attacks. These can be quickly detected in power systems using standard graph algorithms. Known secure phase measurement units [PMUs] can be used as countermeasures against an arbitrary collection of cyber attacks. Finding the minimum number of necessary PMUs is NP-hard. It is shown that p + 1 PMUs at carefully chosen buses are sufficient to neutralize a collection of p cyber attacks.

  14. Situational awareness of a coordinated cyber attack

    NASA Astrophysics Data System (ADS)

    Sudit, Moises; Stotz, Adam; Holender, Michael

    2005-03-01

    As technology continues to advance, services and capabilities become computerized, and an ever increasing amount of business is conducted electronically the threat of cyber attacks gets compounded by the complexity of such attacks and the criticality of the information which must be secured. A new age of virtual warfare has dawned in which seconds can differentiate between the protection of vital information and/or services and a malicious attacker attaining their goal. In this paper we present a novel approach in the real-time detection of multistage coordinated cyber attacks and the promising initial testing results we have obtained. We introduce INFERD (INformation Fusion Engine for Real-time Decision-making), an adaptable information fusion engine which performs fusion at levels zero, one, and two to provide real-time situational assessment and its application to the cyber domain in the ECCARS (Event Correlation for Cyber Attack Recognition System) system. The advantages to our approach are fourfold: (1) The complexity of the attacks which we consider, (2) the level of abstraction in which the analyst interacts with the attack scenarios, (3) the speed at which the information fusion is presented and performed, and (4) our disregard for ad-hoc rules or a priori parameters.

  15. Effect of Metarhizium anisopliae on the Fertility and Fecundity of Two Species of Fruit Flies and Horizontal Transmission of Mycotic Infection

    PubMed Central

    Sookar, P.; Bhagwant, S.; Allymamod, M.N.

    2014-01-01

    In Mauritius, the peach fruit fly, Bactrocera zonata Saunders (Diptera: Tephritidae), and the melon fly, Bactrocera cucurbitae (Coquillett), are the major pest of fruits and vegetables, respectively. Fruit growers make use of broad-spectrum insecticides to protect their crops from fruit fly attack. This method of fruit fly control is hazardous to the environment and is a threat to beneficial insects. The entomopathogenic fungus, Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae), which was isolated from the soils of Mauritius, was used to investigate whether fungus-treated adult fruit flies could transfer conidia to non-treated flies during mating, and whether fungal infection could have an effect on mating behavior, fecundity, and fertility of the two female fruit fly species. When treated male flies were maintained together with non-treated female flies, they were able to transmit infection to untreated females, resulting in high mortalities. Similarly, fungus-infected female flies mixed with untreated males also transmitted infections to males, also resulting in high mortalities. Infection by M. anisopliae also resulted in the reduction of the number of eggs produced by females of B. cucurbitae. The results suggest that M. anisopliae may have potential for use in integrated control programs of B. zonata and B. cucurbitae using the sterile insect technique in Mauritius. PMID:25201230

  16. Transcriptional and Metabolic Reprogramming of Host Plants Following Hessian Fly Attack during Compatible and Incompatible Interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant defense involves three major steps: surveillance, signal transduction, and the production of defense chemicals. A great deal of information on signal perception and transduction has been revealed in numerous plant-parasite systems. Here we investigated changes in metabolic pathways which mig...

  17. Attack of the flying snakes: formation of isolated H I clouds by fragmentation of long streams

    NASA Astrophysics Data System (ADS)

    Taylor, R.; Davies, J. I.; Jáchym, P.; Keenan, O.; Minchin, R. F.; Palouš, J.; Smith, R.; Wünsch, R.

    2016-09-01

    The existence of long (>100 kpc) H I streams and small (<20 kpc) free-floating H I clouds is well known. While the formation of the streams has been investigated extensively, and the isolated clouds are often purported to be interaction debris, little research has been done on the formation of optically dark H I clouds that are not part of a larger stream. One possibility is that such features result from the fragmentation of more extended streams, while another idea is that they are primordial, optically dark galaxies. We test the validity of the fragmentation scenario (via harassment) using numerical simulations. In order to compare our numerical models with observations, we present catalogues of both the known long H I streams (42 objects) and free-floating H I clouds suggested as dark galaxy candidates (51 objects). In particular, we investigate whether it is possible to form compact features with high velocity widths (>100 km s-1), similar to observed clouds which are otherwise intriguing dark galaxy candidates. We find that producing such features is possible but extremely unlikely, occurring no more than 0.2% of the time in our simulations. In contrast, we find that genuine dark galaxies could be extremely stable to harassment and remain detectable even after 5 Gyr in the cluster environment (with the important caveat that our simulations only explore harassment and do not yet include the intracluster medium, heating and cooling, or star formation). We also discuss the possibility that such objects could be the progenitors of recently discovered ultra diffuse galaxies.

  18. Applying high resolution SyXRD analysis on sulfate attacked concrete field samples

    SciTech Connect

    Stroh, J.; Schlegel, M.-C.; Irassar, E.F.; Meng, B.; Emmerling, F.

    2014-12-15

    High resolution synchrotron X-ray diffraction (SyXRD) was applied for a microstructural profile analysis of concrete deterioration after sulfate attack. The cement matrices consist of ordinary Portland cement and different amounts of supplementary cementitious materials, such as fly ash, natural pozzolana and granulated blast furnace slag. The changes of the phase composition were determined along the direction of sulfate ingress. This approach allows the identification of reaction fronts and zones of different phase compositions and conclusions about the mechanisms of sulfate attack. Two reaction fronts were localized in the initial 4 mm from the sample surface. The mechanism of deterioration caused by the exposition in the sulfate-bearing soil is discussed. SyXRD is shown to be a reliable method for investigation of cementitious materials with aggregates embedded in natural environments.

  19. Advanced fighter technology integration (AFTI)/F-16 Automated Maneuvering Attack System final flight test results

    NASA Technical Reports Server (NTRS)

    Dowden, Donald J.; Bessette, Denis E.

    1987-01-01

    The AFTI F-16 Automated Maneuvering Attack System has undergone developmental and demonstration flight testing over a total of 347.3 flying hours in 237 sorties. The emphasis of this phase of the flight test program was on the development of automated guidance and control systems for air-to-air and air-to-ground weapons delivery, using a digital flight control system, dual avionics multiplex buses, an advanced FLIR sensor with laser ranger, integrated flight/fire-control software, advanced cockpit display and controls, and modified core Multinational Stage Improvement Program avionics.

  20. Effect of migraine attacks on paracetamol absorption.

    PubMed Central

    Tokola, R A; Neuvonen, P J

    1984-01-01

    The absorption of effervescent paracetamol (1000 mg) was investigated in nine female patients during a migraine attack and in the same patients when headache free. Migraine attack decreased (P less than 0.05) the areas under the serum paracetamol concentration-time curves (AUC) of 0-2 h, 0-4 h and 0-6 h and the peak serum concentration. The severity of nausea correlated significantly with the decrease in the AUC values. Our results support findings of delayed gastric emptying in migraine attacks. Both a delay and an impairment of drug absorption may follow. PMID:6529526

  1. The effects of angle-of-attack indication on aircraft control in the event of an airspeed indicator malfunction

    NASA Astrophysics Data System (ADS)

    Boesser, Claas Tido

    with a frozen airspeed indicator, pilots flying with an angle-of-attack indicator were producing less airspeed and glideslope deviation than pilots who were flying without an angle-of-attack indicator. Furthermore, in the absence of airspeed information, pilots with an angle-of-attack indicator were less prone to slow the aircraft to an airspeed at which the aural stall-warning activated. Overall, the results of this experiment provide support for making aerodynamic information available to the pilot, thus contributing empirical results to the aviation-safety debate over the effectiveness of angle-of-attack information displays.

  2. Identifying and Analyzing Web Server Attacks

    SciTech Connect

    Seifert, Christian; Endicott-Popovsky, Barbara E.; Frincke, Deborah A.; Komisarczuk, Peter; Muschevici, Radu; Welch, Ian D.

    2008-08-29

    Abstract: Client honeypots can be used to identify malicious web servers that attack web browsers and push malware to client machines. Merely recording network traffic is insufficient to perform comprehensive forensic analyses of such attacks. Custom tools are required to access and analyze network protocol data. Moreover, specialized methods are required to perform a behavioral analysis of an attack, which helps determine exactly what transpired on the attacked system. This paper proposes a record/replay mechanism that enables forensic investigators to extract application data from recorded network streams and allows applications to interact with this data in order to conduct behavioral analyses. Implementations for the HTTP and DNS protocols are presented and their utility in network forensic investigations is demonstrated.

  3. Recovery of infrastructure networks after localised attacks.

    PubMed

    Hu, Fuyu; Yeung, Chi Ho; Yang, Saini; Wang, Weiping; Zeng, An

    2016-01-01

    The stability of infrastructure network is always a critical issue studied by researchers in different fields. A lot of works have been devoted to reveal the robustness of the infrastructure networks against random and malicious attacks. However, real attack scenarios such as earthquakes and typhoons are instead localised attacks which are investigated only recently. Unlike previous studies, we examine in this paper the resilience of infrastructure networks by focusing on the recovery process from localised attacks. We introduce various preferential repair strategies and found that they facilitate and improve network recovery compared to that of random repairs, especially when population size is uneven at different locations. Moreover, our strategic repair methods show similar effectiveness as the greedy repair. The validations are conducted on simulated networks, and on real networks with real disasters. Our method is meaningful in practice as it can largely enhance network resilience and contribute to network risk reduction. PMID:27075559

  4. Women's Heart Disease: Heart Attack Symptoms

    MedlinePlus

    ... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter 2014 Table ... NHLBI has uncovered some of the causes of heart diseases and conditions, as well as ways to prevent ...

  5. On localization attacks against cloud infrastructure

    NASA Astrophysics Data System (ADS)

    Ge, Linqiang; Yu, Wei; Sistani, Mohammad Ali

    2013-05-01

    One of the key characteristics of cloud computing is the device and location independence that enables the user to access systems regardless of their location. Because cloud computing is heavily based on sharing resource, it is vulnerable to cyber attacks. In this paper, we investigate a localization attack that enables the adversary to leverage central processing unit (CPU) resources to localize the physical location of server used by victims. By increasing and reducing CPU usage through the malicious virtual machine (VM), the response time from the victim VM will increase and decrease correspondingly. In this way, by embedding the probing signal into the CPU usage and correlating the same pattern in the response time from the victim VM, the adversary can find the location of victim VM. To determine attack accuracy, we investigate features in both the time and frequency domains. We conduct both theoretical and experimental study to demonstrate the effectiveness of such an attack.

  6. Heart attack - what to ask your doctor

    MedlinePlus

    A heart attack occurs when blood flow to a part of your heart is blocked for a period of time ... muscle is damaged. It is also called a myocardial infarction (MI). Angina is pain or pressure in the ...

  7. Dengue Virus May Bolster Zika's Attack

    MedlinePlus

    ... news/fullstory_159534.html Dengue Virus May Bolster Zika's Attack Prior exposure to this other mosquito-borne ... dengue fever virus may increase the severity of Zika virus, a new study says. Early stage laboratory ...

  8. Heart attack - what to ask your doctor

    MedlinePlus

    ... muscle is damaged. It is also called a myocardial infarction (MI). Watch this video about: Coronary artery disease ... help you take care of yourself after a heart attack. Questions What are the signs and symptoms that ...

  9. Recovery of infrastructure networks after localised attacks

    PubMed Central

    Hu, Fuyu; Yeung, Chi Ho; Yang, Saini; Wang, Weiping; Zeng, An

    2016-01-01

    The stability of infrastructure network is always a critical issue studied by researchers in different fields. A lot of works have been devoted to reveal the robustness of the infrastructure networks against random and malicious attacks. However, real attack scenarios such as earthquakes and typhoons are instead localised attacks which are investigated only recently. Unlike previous studies, we examine in this paper the resilience of infrastructure networks by focusing on the recovery process from localised attacks. We introduce various preferential repair strategies and found that they facilitate and improve network recovery compared to that of random repairs, especially when population size is uneven at different locations. Moreover, our strategic repair methods show similar effectiveness as the greedy repair. The validations are conducted on simulated networks, and on real networks with real disasters. Our method is meaningful in practice as it can largely enhance network resilience and contribute to network risk reduction. PMID:27075559

  10. Recovery of infrastructure networks after localised attacks

    NASA Astrophysics Data System (ADS)

    Hu, Fuyu; Yeung, Chi Ho; Yang, Saini; Wang, Weiping; Zeng, An

    2016-04-01

    The stability of infrastructure network is always a critical issue studied by researchers in different fields. A lot of works have been devoted to reveal the robustness of the infrastructure networks against random and malicious attacks. However, real attack scenarios such as earthquakes and typhoons are instead localised attacks which are investigated only recently. Unlike previous studies, we examine in this paper the resilience of infrastructure networks by focusing on the recovery process from localised attacks. We introduce various preferential repair strategies and found that they facilitate and improve network recovery compared to that of random repairs, especially when population size is uneven at different locations. Moreover, our strategic repair methods show similar effectiveness as the greedy repair. The validations are conducted on simulated networks, and on real networks with real disasters. Our method is meaningful in practice as it can largely enhance network resilience and contribute to network risk reduction.

  11. Fly on the Wall

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald

    2003-01-01

    The email was addressed not only to me, but also to all the Project Knowledge Sharing Community at Ames Research Center. We were invited to sit in on a major project review as a new experiment in knowledge sharing. This first-of-its-kind opportunity had been conceived by Claire Smith, who leads the knowledge sharing program, as well as heading up the Center's Project Leadership Development Program and serving as coordinator of the APPL-West program at Ames. The objective was to offer Ames project practitioners the opportunity to observe project-review processes as they happen. Not that I haven't participated in my share of project reviews, but this seemed like a great way for me to get up-to-date about a new project, the Kepler mission, and to experience a review from a new perspective. Typically, when you're being reviewed, it's difficult to see what's happening objectively-the same way it is on a project. Presenters are always thinking, 'Okay, what's on my slides? How much time do I have left? What are they going to ask me?' So when Claire's email pinged on my computer, I quickly responded by asking her to save a place for me. It was to be an informational review about progress on the project: what the team had done, where they were going, and what they needed to do to get there. There were people on the project team from all over the United States, and it was the first time for them to get together from all aspects of the project. For our part, as observers, we were asked to abide by a couple of rules: Don't ask any questions. and don't talk about the specifics of what we saw or heard. The idea was that we weren't supposed to be noticed. We weren't to buzz around and bother people. Hence the name for this experinient: Fly on the Wall.

  12. XMM flying beautifully

    NASA Astrophysics Data System (ADS)

    1999-12-01

    The early orbit phase came to an end on 16 December after XMM had been manoeuvred to its final orbit. This required four firings of its thrusters, on successive passages at apogee, in order to increase XMM's velocity, thus elongating its orbit and raising the perigee from 826 km to 7,365 km. One burn was then made to fine tune the apogee to around 114,000km. The spacecraft, being tracked by ground stations in Perth, Kourou and Villafranca, is now circling the Earth in this highly elliptical orbit once every 48 hours. The XMM flight operations staff have found themselves controlling a spacecraft that responds exceptionally well. During these first orbits, the satellite has been oriented several times with razor-sharp precision. On board systems have responded without incident to several thousand instructions sent by controllers. "XMM is flying so beautifully" says Dietmar Heger, XMM Spacecraft Operations Manager. "The satellite is behaving better in space than all our pre-launch simulations and we have been able to adjust our shifts to this more relaxed situation". On his return from French Guiana, Robert Lainé, XMM Project Manager immediately visited the Darmstadt Mission Control Centre, at ESOC. "The perfect behaviour of XMM at this early stage reflects the constructive cooperation of European industrial companies and top scientists. Spacecraft operations are in the hands of professionals who will endeavour to fulfill the expectations of the astronomers and astrophysicists of the world. I am very happy that ESA could provide them with such a wonderful precision tool". During the early orbit phase, controllers have activated part of XMM's science payload. The three EPIC X-ray cameras have been switched on and vented. On 17 December the telescope doors were opened allowing the spacecraft's golden X-ray Multi Mirror modules to see the sky. The Optical Monitor telescope door was opened on 18 December. During this last weekend, XMM's Radiation Monitor which records

  13. Cyber Security Audit and Attack Detection Toolkit

    SciTech Connect

    Peterson, Dale

    2012-05-31

    This goal of this project was to develop cyber security audit and attack detection tools for industrial control systems (ICS). Digital Bond developed and released a tool named Bandolier that audits ICS components commonly used in the energy sector against an optimal security configuration. The Portaledge Project developed a capability for the PI Historian, the most widely used Historian in the energy sector, to aggregate security events and detect cyber attacks.

  14. Distinguishing attack and second-preimage attack on encrypted message authentication codes (EMAC)

    NASA Astrophysics Data System (ADS)

    Ariwibowo, Sigit; Windarta, Susila

    2016-02-01

    In this paper we show that distinguisher on CBC-MAC can be applied to Encrypted Message Authentication Code (EMAC) scheme. EMAC scheme in general is vulnerable to distinguishing attack and second preimage attack. Distinguishing attack simulation on AES-EMAC using 225 message modifications, no collision have been found. According to second preimage attack simulation on AES-EMAC no collision found between EMAC value of S1 and S2, i.e. no second preimage found for messages that have been tested. Based on distinguishing attack simulation on truncated AES-EMAC we found collision in every message therefore we cannot distinguish truncated AES-EMAC with random function. Second-preimage attack is successfully performed on truncated AES-EMAC.

  15. Spread spectrum watermarking: malicious attacks and counterattacks

    NASA Astrophysics Data System (ADS)

    Hartung, Frank H.; Su, Jonathan K.; Girod, Bernd

    1999-04-01

    Most watermarking methods for images and video have been proposed are based on ideas from spread spectrum radio communications, namely additive embedding of a (signal adaptive or non-adaptive) pseudo-noise watermark pattern, and watermark recovery by correlation. Even methods that are not presented as spread spectrum methods often build on these principles. Recently, some skepticism about the robustness of spread spectrum watermarks has arisen, specifically with the general availability of watermark attack software which claim to render most watermarks undetectable. In fact, spread spectrum watermarks and watermark detectors in their simplest form are vulnerable to a variety of attacks. However, with appropriate modifications to the embedding and extraction methods, spread spectrum methods can be made much more resistant against such attacks. In this paper, we review proposed attacks on spread spectrum watermarks are systematically. Further, modifications for watermark embedding and extraction are presented to avoid and counterattack these attacks. Important ingredients are, for example, to adapt the power spectrum of the watermark to the host signal power spectrum, and to employ an intelligent watermark detector with a block-wise multi-dimensional sliding correlator, which can recover the watermark even in the presence of geometric attacks.

  16. Fruit Flies Help Human Sleep Research

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Fruit Flies Help Human Sleep Research Past Issues / Summer ... courtesy of NIGMS Neuroscientist Chiara Cirelli uses experimental fruit flies to study sleep. Although it may be ...

  17. Rich Rogers Flying Over Greenland Icecap

    NASA Video Gallery

    Ihis is a view from the NASA P3 aircraft cockpit as it flies 1000 feet over the Greenland icecap during Operation Icebridge mission, which flies each March-May. The end of video shows an ice camp w...

  18. Fruit Flies Help Human Sleep Research

    MedlinePlus

    ... Current Issue Past Issues Fruit Flies Help Human Sleep Research Past Issues / Summer 2007 Table of Contents ... Chiara Cirelli uses experimental fruit flies to study sleep. Although it may be tough to imagine a ...

  19. John Glenn: His first Flying Lesson Remembered

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Pilot Harry Clever remembers giving John Glenn his first flying lesson. From: The John Glenn Story: Summary of astronaut John Glenn's flying career, from naval aviation training to space flight. The Mercury project is featured as John Glenn flies the Friendship 7 spacecraft. President John F. Kennedy presents the NASA Distinguished service Medal to Astronaught John Glenn.

  20. Sugar feeding in adult stable flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult stable flies, (Stomoxys calcitrans (L.)), are known to feed readily on sugars in the laboratory. However, little is known concerning the extent of stable fly sugar feeding in wild populations. We examined the frequency of sugar feeding in stable flies in rural and urban environments. In additi...

  1. Utilization of fly ash in metallic composites

    SciTech Connect

    Rohatgi, P.K.; Guo, R.Q.; Golden, D.M.

    1996-10-01

    Fly ash particles have been successfully dispersed into aluminum alloy to make aluminum alloy-fly ash composites (Ashalloy) at University of Wisconsin-Milwaukee. Additions of solid and hollow particles of fly ash reduce the cost and density of aluminum castings while increasing their performance. Ashalloy represents a candidate material for high value added use of fly ash, while reducing the disposal volumes of fly ash for the electric utility industry and making the US foundries more competitive. The fly ash particle distribution in the matrix aluminum alloy and the microstructure of aluminum-fly ash composite was determined. Selected properties of cast aluminum-fly ash composites are also presented in this paper. Mechanical properties of aluminum-fly ash composites show that the composite possesses higher hardness and higher elastic modulus compared to the matrix alloy. The flow behavior of molten aluminum-fly ash slurries along with the components cast in aluminum-fly ash composites will be presented. Fly ash containing metal components have potential applications in covers, shrouds, casings, manifolds, valve covers, garden furniture, engine blocks in automotive, small engine and electromechanical industry sector.

  2. Molecular diagnostics & phylogenetics of filth fly parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several species of synanthropic muscoid flies, often referred to as filth flies, breed in animal wastes and are serious pests of humans and livestock. Pteromalid wasps are among the most promising biological control agents for these filth flies. Because of their small size and relative lack of morph...

  3. The Spider and the Fly

    ERIC Educational Resources Information Center

    Mellinger, Keith E.; Viglione, Raymond

    2012-01-01

    The Spider and the Fly puzzle, originally attributed to the great puzzler Henry Ernest Dudeney, and now over 100 years old, asks for the shortest path between two points on a particular square prism. We explore a generalization, find that the original solution only holds in certain cases, and suggest how this discovery might be used in the…

  4. Flying Training at West Point.

    ERIC Educational Resources Information Center

    Cannon, M. Hamlin

    During World War Two the United States Military Academy operated a three-year program of instruction. Superimposed on this abbreviated curriculum was full-scale pilot training program. The emphasis of this study is on the problems that arose as a result. Included is a summary of responses to a questionnaire on the value of the flying training…

  5. Physics between a Fly's Ears

    ERIC Educational Resources Information Center

    Denny, Mark

    2008-01-01

    A novel method of localizing the direction of a source of sound has evolved in the auditory system of certain small parasitic flies. A mechanical model of this design has been shown to describe the system well. Here, a simplified version of this mechanical model is presented which demonstrates the key feature: direction estimates of high accuracy…

  6. To Fly in the Sky.

    ERIC Educational Resources Information Center

    Brodie, Carolyn S.

    1995-01-01

    Suggests activities for students that focus on airplanes, famous pilots, and travel. Provides a list of suggested titles with the following topics: history of flight and airplanes; airplanes and flying information; paper and model airplanes; Charles Lindbergh; Amelia Earhart; the Wright Brothers; videos; and picture books. (AEF)

  7. Gyroscopic Instruments for Instrument Flying

    NASA Technical Reports Server (NTRS)

    Brombacher, W G; Trent, W C

    1938-01-01

    The gyroscopic instruments commonly used in instrument flying in the United States are the turn indicator, the directional gyro, the gyromagnetic compass, the gyroscopic horizon, and the automatic pilot. These instruments are described. Performance data and the method of testing in the laboratory are given for the turn indicator, the directional gyro, and the gyroscopic horizon. Apparatus for driving the instruments is discussed.

  8. Choreographing the fly's danse macabre.

    PubMed

    Poon, Peter C; Pletcher, Scott D

    2007-08-01

    In several species, immune signaling networks are emerging as critical modulators of disease resistance, energy metabolism, and aging. In this issue of Cell Metabolism, Ren et al. (2007) lay the groundwork for dissecting the mechanisms of this coordination by characterizing the interplay between microbial pathogens and aging in the fly. PMID:17681142

  9. Performance Evaluation of AODV with Blackhole Attack

    NASA Astrophysics Data System (ADS)

    Dara, Karuna

    2010-11-01

    A Mobile Ad Hoc Network (MANET) is a temporary network set up by a wireless mobile computers moving arbitrary in the places that have no network infrastructure. These nodes maintain connectivity in a decentralized manner. Since the nodes communicate with each other, they cooperate by forwarding data packets to other nodes in the network. Thus the nodes find a path to the destination node using routing protocols. However, due to security vulnerabilities of the routing protocols, mobile ad-hoc networks are unprotected to attacks of the malicious nodes. One of these attacks is the Black Hole Attack against network integrity absorbing all data packets in the network. Since the data packets do not reach the destination node on account of this attack, data loss will occur. In this paper, we simulated the black hole attack in various mobile ad-hoc network scenarios using AODV routing protocol of MANET and have tried to find a effect if number of nodes are increased with increase in malicious nodes.

  10. Individual triptan selection in migraine attack therapy.

    PubMed

    Belvís, Robert; Pagonabarraga, Javier; Kulisevsky, Jaime

    2009-01-01

    About 6% of men and 18% of women suffer migraine attacks. Migraine can induce a great impact in the quality of life of the patient and the costs of medical care and lost productivity can be also high. There are two therapeutic approaches in the treatment of migraine: preventive therapy and acute treatment of migraine attack. Immediate treatment with selective serotonin [5-HT1B/1T] receptor agonists (so-called triptans) is the first-line option in the acute treatment of moderate-severe migraine attacks. The introduction in early nineties of triptans was a revolution in migraine therapy and evidences about their efficacy are at present irrefutable. At the moment, there are seven marketed molecules: sumatriptan, rizatriptan, zolmitriptan, eletriptan, naratriptan, almotriptan and frovatriptan. Obviously, every molecule has different pharmacokinetic and pharmacodinamic properties and, moreover, some triptans have several formulations: tablets, dissolvable tablets, nasal and injections. The prescription of one of these seven triptans for a specified patient is based in the drug profile: efficacy, safety, pharmacokinetics and pharmacodynamics. Despite there are a lot of published studies using triptans, no clinical trial has analyzed all the molecules at the same time. Other data to take account in the final prescription are clinical characteristics of the migraine attack and patient characteristics: labour aspects, style of life and the patient medical history. We present a state-of-the-art of the triptan selection in treatment of moderate-severe migraine attacks. PMID:19149716

  11. Zebras and Biting Flies: Quantitative Analysis of Reflected Light from Zebra Coats in Their Natural Habitat

    PubMed Central

    Britten, Kenneth H.; Thatcher, Timothy D.; Caro, Tim

    2016-01-01

    Experimental and comparative evidence suggests that the striped coats of zebras deter biting fly attack, but the mechanisms by which flies fail to target black-and-white mammals are still opaque. Two hypotheses have been proposed: stripes might serve either to defeat polarotaxis or to obscure the form of the animal. To test these hypotheses, we systematically photographed free-living plains zebras in Africa. We found that black and white stripes both have moderate polarization signatures with a similar angle, though the degree (magnitude) of polarization in white stripes is lower. When we modeled the visibility of these signals from different distances, we found that polarization differences between stripes are invisible to flies more than 10 m away because they are averaged out by the flies’ low visual resolution. At any distance, however, a positively polarotactic insect would have a distinct signal to guide its visual approach to a zebra because we found that polarization of light reflecting from zebras is higher than from surrounding dry grasses. We also found that the stripes themselves are visible to flies at somewhat greater distances (up to 20 m) than the polarization contrast between stripes. Together, these observations support hypotheses in which zebra stripes defeat visually guided orienting behavior in flies by a mechanism independent of polarotaxis. PMID:27223616

  12. Coronary Artery Dissection: Not Just a Heart Attack

    MedlinePlus

    ... Stroke More Coronary Artery Dissection: Not Just a Heart Attack Updated:May 24,2016 Sometimes a heart attack ... Disease Go Red For Women Types of aneurysms Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) • ...

  13. A Game Theoretic Approach to Cyber Attack Prediction

    SciTech Connect

    Peng Liu

    2005-11-28

    The area investigated by this project is cyber attack prediction. With a focus on correlation-based prediction, current attack prediction methodologies overlook the strategic nature of cyber attack-defense scenarios. As a result, current cyber attack prediction methodologies are very limited in predicting strategic behaviors of attackers in enforcing nontrivial cyber attacks such as DDoS attacks, and may result in low accuracy in correlation-based predictions. This project develops a game theoretic framework for cyber attack prediction, where an automatic game-theory-based attack prediction method is proposed. Being able to quantitatively predict the likelihood of (sequences of) attack actions, our attack prediction methodology can predict fine-grained strategic behaviors of attackers and may greatly improve the accuracy of correlation-based prediction. To our best knowledge, this project develops the first comprehensive framework for incentive-based modeling and inference of attack intent, objectives, and strategies; and this project develops the first method that can predict fine-grained strategic behaviors of attackers. The significance of this research and the benefit to the public can be demonstrated to certain extent by (a) the severe threat of cyber attacks to the critical infrastructures of the nation, including many infrastructures overseen by the Department of Energy, (b) the importance of cyber security to critical infrastructure protection, and (c) the importance of cyber attack prediction to achieving cyber security.

  14. Survey of microhymenoptera (Hymenoptera: Chalcidoidea) parasitizing filth flies (Diptera: Muscidae, Calliphoridae) breeding in refuse and poultry farms in peninsular Malaysia.

    PubMed

    Sulaiman, S; Omar, B; Omar, S; Jeffery, J; Ghauth, I; Busparani, V

    1990-09-01

    Nine species of parasitoids were found parasitizing the pupae of filth flies breeding in refuse dumps and poultry farms throughout peninsular Malaysia. Spalangia were most common, consisting of Spalangia endius Walker, S. cameroni Perkins, S. gemina Boucek, S. nigroaenea Curtis, and two undescribed species. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani, Dirhinus himalayanus Westwood, and an unidentified Hymenoptera. The parasitized fly hosts included Musca domestica L., Chrysomya megacephala (F.), Fannia sp., and Ophyra sp. S. endius was the most common parasitoid attacking M. domestica and C. megacephala at refuse dumps and poultry farms D. himalayanus were found to parasitize only M. domestica pupae collected at poultry farms. PMID:2231622

  15. LUNA: low-flying UAV-based forest monitoring system

    NASA Astrophysics Data System (ADS)

    Keizer, Jan Jacob; Pereira, Luísa; Pinto, Glória; Alves, Artur; Barros, Antonio; Boogert, Frans-Joost; Cambra, Sílvia; de Jesus, Cláudia; Frankenbach, Silja; Mesquita, Raquel; Serôdio, João; Martins, José; Almendra, Ricardo

    2015-04-01

    The LUNA project is aiming to develop an information system for precision forestry and, in particular, the monitoring of eucalypt plantations that is first and foremost based on multi-spectral imagery acquired using low-flying uav's. The presentation will focus on the first phase of image acquisition, processing and analysis for a series of pot experiments addressing main threats for early-stage eucalypt plantations in Portugal, i.e. acute , chronic and cyclic hydric stress, nutrient stress, fungal infections and insect plague attacks. The imaging results will be compared with spectroscopic measurements as well as with eco-physiological and plant morphological measurements. Furthermore, the presentation will show initial results of the project's second phase, comprising field tests in existing eucalypt plantations in north-central Portugal.

  16. Attacks on public telephone networks: technologies and challenges

    NASA Astrophysics Data System (ADS)

    Kosloff, T.; Moore, Tyler; Keller, J.; Manes, Gavin W.; Shenoi, Sujeet

    2003-09-01

    Signaling System 7 (SS7) is vital to signaling and control in America's public telephone networks. This paper describes a class of attacks on SS7 networks involving the insertion of malicious signaling messages via compromised SS7 network components. Three attacks are discussed in detail: IAM flood attacks, redirection attacks and point code spoofing attacks. Depending on their scale of execution, these attacks can produce effects ranging from network congestion to service disruption. Methods for detecting these denial-of-service attacks and mitigating their effects are also presented.

  17. Consideration of Eurytoma sivinskii Gates and Grissell, a eurytomid (Hymenoptera) with unusual foraging behaviors, as a biological control agent of tephritid (Diptera) fruit flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe some aspects of the oviposition bevavior and demography of a recently discovered Mexican parasitoid species, Eurytoma sivinskii Gates and Grissell (Hymenoptera: Eurytomidae), exhibiting the novel behavior of attacking tephritid fruit fly pupae (Anastrepha spp.) buried in the soil. Rates...

  18. An overview of tropical pest species of bactrocera fruit flies (Diptera:Tephritidae) and the integration of biopesticides with other biological approaches for their management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit flies (Diptera:Tephritidae) are among the most economically important pest species in the world, attacking a wide range of fruits and fleshy vegetables throughout tropical and sub-tropical areas of the world. These species are such devastating crop pests that major control and eradication prog...

  19. FliO regulation of FliP in the formation of the Salmonella enterica flagellum.

    PubMed

    Barker, Clive S; Meshcheryakova, Irina V; Kostyukova, Alla S; Samatey, Fadel A

    2010-09-01

    The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO₄₃-₁₂₅ or FliO₁-₉₅ was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO₄₃-₁₂₅, should contain beta-structure and alpha-helices. FliO₄₃-₁₂₅-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners. PMID:20941389

  20. Characterization of attacks on public telephone networks

    NASA Astrophysics Data System (ADS)

    Lorenz, Gary V.; Manes, Gavin W.; Hale, John C.; Marks, Donald; Davis, Kenneth; Shenoi, Sujeet

    2001-02-01

    The U.S. Public Telephone Network (PTN) is a massively connected distributed information systems, much like the Internet. PTN signaling, transmission and operations functions must be protected from physical and cyber attacks to ensure the reliable delivery of telecommunications services. The increasing convergence of PTNs with wireless communications systems, computer networks and the Internet itself poses serious threats to our nation's telecommunications infrastructure. Legacy technologies and advanced services encumber well-known and as of yet undiscovered vulnerabilities that render them susceptible to cyber attacks. This paper presents a taxonomy of cyber attacks on PTNs in converged environments that synthesizes exploits in computer and communications network domains. The taxonomy provides an opportunity for the systematic exploration of mitigative and preventive strategies, as well as for the identification and classification of emerging threats.

  1. Responding to chemical attack. Final report

    SciTech Connect

    Bagley, R.W.

    1991-02-11

    In view of Iraq's stated intention of using chemical weapons in the Persian Gulf War, the Coalition forces must be prepared to respond. Iraq is capable of conducting such an attack. While the use of chemical weapons may not be militarily significant, the political effect of the use and the response to it may be very significant. Responses including the use of chemical and nuclear weapons are assessed in terms of their legality, political cost, and military effectiveness and found unacceptable. Reliance on diplomatic protests and on post-war criminal sanctions are judged ineffective. A response in the form of increased conventional attack on the Iraqi chemical infrastructure is recommended because that response will preserve the present Coalition, effectively counter the chemical attack, contribute to regional stability, and enhance the reputation of the United States for lawfulness and dependability.

  2. Robustness of interdependent networks under targeted attack

    NASA Astrophysics Data System (ADS)

    Huang, Xuqing; Gao, Jianxi; Buldyrev, Sergey V.; Havlin, Shlomo; Stanley, H. Eugene

    2011-06-01

    When an initial failure of nodes occurs in interdependent networks, a cascade of failure between the networks occurs. Earlier studies focused on random initial failures. Here we study the robustness of interdependent networks under targeted attack on high or low degree nodes. We introduce a general technique which maps the targeted-attack problem in interdependent networks to the random-attack problem in a transformed pair of interdependent networks. We find that when the highly connected nodes are protected and have lower probability to fail, in contrast to single scale-free (SF) networks where the percolation threshold pc=0, coupled SF networks are significantly more vulnerable with pc significantly larger than zero. The result implies that interdependent networks are difficult to defend by strategies such as protecting the high degree nodes that have been found useful to significantly improve robustness of single networks.

  3. Robustness of interdependent networks under targeted attack

    NASA Astrophysics Data System (ADS)

    Huang, Xuqing; Gao, Jianxi; Buldyrev, Sergey; Havlin, Shlomo; Stanley, H. Eugene

    2012-02-01

    When an initial failure of nodes occurs in interdependent networks, a cascade of failure between the networks occurs. Earlier studies focused on random initial failures. Here we study the robustness of interdependent networks under targeted attack on high or low degree nodes. We introduce a general technique which maps the targeted-attack problem in interdependent networks to the random-attack problem in a transformed pair of interdependent networks. We find that when the highly connected nodes are protected and have lower probability to fail, in contrast to single scale-free (SF) networks where the percolation threshold pc=0, coupled SF networks are significantly more vulnerable with pc significantly larger than zero. The result implies that interdependent networks are difficult to defend by strategies such as protecting the high degree nodes that have been found useful to significantly improve robustness of single networks.

  4. Quantifying Mixed Uncertainties in Cyber Attacker Payoffs

    SciTech Connect

    Chatterjee, Samrat; Halappanavar, Mahantesh; Tipireddy, Ramakrishna; Oster, Matthew R.; Saha, Sudip

    2015-04-15

    Representation and propagation of uncertainty in cyber attacker payoffs is a key aspect of security games. Past research has primarily focused on representing the defender’s beliefs about attacker payoffs as point utility estimates. More recently, within the physical security domain, attacker payoff uncertainties have been represented as Uniform and Gaussian probability distributions, and intervals. Within cyber-settings, continuous probability distributions may still be appropriate for addressing statistical (aleatory) uncertainties where the defender may assume that the attacker’s payoffs differ over time. However, systematic (epistemic) uncertainties may exist, where the defender may not have sufficient knowledge or there is insufficient information about the attacker’s payoff generation mechanism. Such epistemic uncertainties are more suitably represented as probability boxes with intervals. In this study, we explore the mathematical treatment of such mixed payoff uncertainties.

  5. Counteracting Power Analysis Attacks by Masking

    NASA Astrophysics Data System (ADS)

    Oswald, Elisabeth; Mangard, Stefan

    The publication of power analysis attacks [12] has triggered a lot of research activities. On the one hand these activities have been dedicated toward the development of secure and efficient countermeasures. On the other hand also new and improved attacks have been developed. In fact, there has been a continuous arms race between designers of countermeasures and attackers. This chapter provides a brief overview of the state-of-the art in the arms race in the context of a countermeasure called masking. Masking is a popular countermeasure that has been extensively discussed in the scientific community. Numerous articles have been published that explain different types of masking and that analyze weaknesses of this countermeasure.

  6. Attack optimization for unequal moderate forces

    SciTech Connect

    Canavan, G.H.

    1997-06-01

    Attack allocation optimizations produce stability indices for unsymmetrical forces that indicate significant regions of both stability and instability and that have their minimum values roughly when the two sides have equal forces. This note derives combined stability indices for unsymmetrical offensive force configurations. The indices are based on optimal allocations of offensive missiles between vulnerable missiles and value based on the minimization of first strike cost, which is done analytically. Exchanges are modeled probabalistically and their results are converted into first and second strike costs through approximations to the damage to the value target sets held at risk. The stability index is the product of the ratio of first to second strike costs seen by the two sides. Optimal allocations scale directly on the opponent`s vulnerable missiles, inversely on one`s own total weapons, and only logarithmically on the attacker`s damage preference, kill probability, and relative target set. The defender`s allocation scales in a similar manner on the attacker`s parameters. First and second strike magnitudes increase roughly linearly for the side with greater forces and decrease linearly for the side with fewer. Conversely, the first and second strike magnitudes decrease for the side with greater forces and increase for the side with fewer. These trends are derived and discussed analytically. The resulting stability indices exhibit a minimum where the two sides have roughly equal forces. If one side has much larger forces than the other, his costs drop to levels low enough that he is relatively insensitive to whether he strikes first or second. These calculations are performed with the analytic attack allocation appropriate for moderate forces, so some differences could be expected for the largest of the forces considered.

  7. Petrographic characterization of economizer fly ash

    SciTech Connect

    Valentim, B.; Hower, J.C.; Soares, S.; Guedes, A.; Garcia, C.; Flores, D.; Oliveira, A.

    2009-11-15

    Policies for reducing NOx emissions have led power plants to restrict O{sub 2}, resulting in high-carbon fly ash production. Therefore, some potentially useful fly ash, such as the economizer fly ash, is discarded without a thorough knowledge of its composition. In order to characterize this type of fly ash, samples were collected from the economizer Portuguese power plant burning two low-sulfur bituminous coals. Characterization was also performed on economizer fly ash subsamples after wet sieving, density and magnetic separation. Analysis included atomic absorption spectroscopy, loss-on-ignition, scanning electron microscopy/energy-dispersive X-ray spectroscopy, optical microscopy, and micro-Raman spectroscopy.

  8. Fly ash chemical classification based on lime

    SciTech Connect

    Fox, J.

    2007-07-01

    Typically, total lime content (CaO) of fly ash is shown in fly ash reports, but its significance is not addressed in US specifications. For certain applications a low lime ash is preferred. When a class C fly ash must be cementitious, lime content above 20% is required. A ternary S-A-C phase diagram pilot is given showing the location of fly ash compositions by coal rank and source in North America. Fly ashes from subbituminous coal from the Powder River Basin usually contain sufficient lime to be cementitious but blending with other coals may result in calcium being present in phases other than tricalcium aluminate. 9 refs., 1 fig.

  9. Discovering Collaborative Cyber Attack Patterns Using Social Network Analysis

    NASA Astrophysics Data System (ADS)

    Du, Haitao; Yang, Shanchieh Jay

    This paper investigates collaborative cyber attacks based on social network analysis. An Attack Social Graph (ASG) is defined to represent cyber attacks on the Internet. Features are extracted from ASGs to analyze collaborative patterns. We use principle component analysis to reduce the feature space, and hierarchical clustering to group attack sources that exhibit similar behavior. Experiments with real world data illustrate that our framework can effectively reduce from large dataset to clusters of attack sources exhibiting critical collaborative patterns.

  10. Airfoil Lift with Changing Angle of Attack

    NASA Technical Reports Server (NTRS)

    Reid, Elliott G

    1927-01-01

    Tests have been made in the atmospheric wind tunnel of the National Advisory Committee for Aeronautics to determine the effects of pitching oscillations upon the lift of an airfoil. It has been found that the lift of an airfoil, while pitching, is usually less than that which would exist at the same angle of attack in the stationary condition, although exceptions may occur when the lift is small or if the angle of attack is being rapidly reduced. It is also shown that the behavior of a pitching airfoil may be qualitatively explained on the basis of accepted aerodynamic theory.

  11. Counterfactual attack on counterfactual quantum key distribution

    NASA Astrophysics Data System (ADS)

    Zhang, Sheng; Wnang, Jian; Tang, Chao Jing

    2012-05-01

    It is interesting that counterfactual quantum cryptography protocols allow two remotely separated parties to share a secret key without transmitting any signal particles. Generally, these protocols, expected to provide security advantages, base their security on a translated no-cloning theorem. Therefore, they potentially exhibit unconditional security in theory. In this letter, we propose a new Trojan horse attack, by which an eavesdropper Eve can gain full information about the key without being noticed, to real implementations of a counterfactual quantum cryptography system. Most importantly, the presented attack is available even if the system has negligible imperfections. Therefore, it shows that the present realization of counterfactual quantum key distribution is vulnerable.

  12. Differential attack on mini-AES

    NASA Astrophysics Data System (ADS)

    Ajeng Gemellia, Asadini Dwi; Indarjani, Santi

    2012-05-01

    This paper presents the results of differential attack on Mini-AES algorithm. The differential trails are constructed using all combinations of propagation ratio without repetition. To give practical results, we implement the key extraction for differential characteristics which have the highest and lowest probability as a comparison. Based on total propagation ratio and complexity resulted, Mini-AES algorithms are vulnerable to differential attack. The best differential characteristic is the differential characteristic using a single active s-box with the propagation ratio of 8 / 16.

  13. Predator versus Prey: Locust Looming-Detector Neuron and Behavioural Responses to Stimuli Representing Attacking Bird Predators

    PubMed Central

    Santer, Roger D.; Rind, F. Claire; Simmons, Peter J.

    2012-01-01

    Many arthropods possess escape-triggering neural mechanisms that help them evade predators. These mechanisms are important neuroethological models, but they are rarely investigated using predator-like stimuli because there is often insufficient information on real predator attacks. Locusts possess uniquely identifiable visual neurons (the descending contralateral movement detectors, DCMDs) that are well-studied looming motion detectors. The DCMDs trigger ‘glides’ in flying locusts, which are hypothesised to be appropriate last-ditch responses to the looms of avian predators. To date it has not been possible to study glides in response to stimuli simulating bird attacks because such attacks have not been characterised. We analyse video of wild black kites attacking flying locusts, and estimate kite attack speeds of 10.8±1.4 m/s. We estimate that the loom of a kite’s thorax towards a locust at these speeds should be characterised by a relatively low ratio of half size to speed (l/|v|) in the range 4–17 ms. Peak DCMD spike rate and gliding response occurrence are known to increase as l/|v| decreases for simple looming shapes. Using simulated looming discs, we investigate these trends and show that both DCMD and behavioural responses are strong to stimuli with kite-like l/|v| ratios. Adding wings to looming discs to produce a more realistic stimulus shape did not disrupt the overall relationships of DCMD and gliding occurrence to stimulus l/|v|. However, adding wings to looming discs did slightly reduce high frequency DCMD spike rates in the final stages of object approach, and slightly delay glide initiation. Looming discs with or without wings triggered glides closer to the time of collision as l/|v| declined, and relatively infrequently before collision at very low l/|v|. However, the performance of this system is in line with expectations for a last-ditch escape response. PMID:23209660

  14. Binocular interactions underlying the classic optomotor responses of flying flies.

    PubMed

    Duistermars, Brian J; Care, Rachel A; Frye, Mark A

    2012-01-01

    In response to imposed course deviations, the optomotor reactions of animals reduce motion blur and facilitate the maintenance of stable body posture. In flies, many anatomical and electrophysiological studies suggest that disparate motion cues stimulating the left and right eyes are not processed in isolation but rather are integrated in the brain to produce a cohesive panoramic percept. To investigate the strength of such inter-ocular interactions and their role in compensatory sensory-motor transformations, we utilize a virtual reality flight simulator to record wing and head optomotor reactions by tethered flying flies in response to imposed binocular rotation and monocular front-to-back and back-to-front motion. Within a narrow range of stimulus parameters that generates large contrast insensitive optomotor responses to binocular rotation, we find that responses to monocular front-to-back motion are larger than those to panoramic rotation, but are contrast sensitive. Conversely, responses to monocular back-to-front motion are slower than those to rotation and peak at the lowest tested contrast. Together our results suggest that optomotor responses to binocular rotation result from the influence of non-additive contralateral inhibitory as well as excitatory circuit interactions that serve to confer contrast insensitivity to flight behaviors influenced by rotatory optic flow. PMID:22375108

  15. Binocular Interactions Underlying the Classic Optomotor Responses of Flying Flies

    PubMed Central

    Duistermars, Brian J.; Care, Rachel A.; Frye, Mark A.

    2012-01-01

    In response to imposed course deviations, the optomotor reactions of animals reduce motion blur and facilitate the maintenance of stable body posture. In flies, many anatomical and electrophysiological studies suggest that disparate motion cues stimulating the left and right eyes are not processed in isolation but rather are integrated in the brain to produce a cohesive panoramic percept. To investigate the strength of such inter-ocular interactions and their role in compensatory sensory–motor transformations, we utilize a virtual reality flight simulator to record wing and head optomotor reactions by tethered flying flies in response to imposed binocular rotation and monocular front-to-back and back-to-front motion. Within a narrow range of stimulus parameters that generates large contrast insensitive optomotor responses to binocular rotation, we find that responses to monocular front-to-back motion are larger than those to panoramic rotation, but are contrast sensitive. Conversely, responses to monocular back-to-front motion are slower than those to rotation and peak at the lowest tested contrast. Together our results suggest that optomotor responses to binocular rotation result from the influence of non-additive contralateral inhibitory as well as excitatory circuit interactions that serve to confer contrast insensitivity to flight behaviors influenced by rotatory optic flow. PMID:22375108

  16. Identification and sequences of the Treponema pallidum fliM', fliY, fliP, fliQ, fliR and flhB' genes.

    PubMed

    Hardham, J M; Frye, J G; Stamm, L V

    1995-12-01

    Information regarding the biology and virulence attributes of Treponema pallidum (Tp) is limited due to the lack of genetic exchange mechanisms and the inability to continuously cultivate this spirochete. We have utilized TnphoA mutagenesis of a Tp genomic DNA library in Escherichia coli (Ec) to identify genes encoding exported proteins, a subset of which are likely to be important in treponemal pathogenesis. We report here the identification and nucleotide (nt) sequence of a 5-kb treponemal DNA insert that contains seven open reading frames (ORFs). The proteins encoded by six of these ORFs have homology with members of a newly described protein family involved in the biogenesis/assembly of flagella and the control of flagellar rotation in Ec, Salmonella typhimurium (St) and Bacillus subtilis (Bs). Certain members of this family are also involved in the export of virulence factors in Yersinia (Yr) spp., St and Shigella flexneri (Sf). We have named these six ORFs fliM', fliY, fliP, fliQ, fliR and flhB'. The operon containing these ORFs has been designated as the fla operon. We hypothesize that the protein products of these genes are involved in the biogenesis/assembly of flagella and the control of flagellar rotation in Tp. PMID:8529894

  17. Susceptibility of 15 mango (Sapindales: Anacardiaceae) cultivars to the attack by Anastrepha ludens and Anastrepha obliqua (Diptera:Tephritidae) and the role of underdeveloped fruit as pest reservoirs: management implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the susceptibility of 15 mango cultivars to the attack of Anastrepha ludens and A. obliqua, the main Tephritid pests of this crop in Mexico. In a field experiment, bagged, fruit-bearing branches were exposed to gravid females of both fly species. Infestation rates, developmental time,...

  18. Intrusion-Tolerant Replication under Attack

    ERIC Educational Resources Information Center

    Kirsch, Jonathan

    2010-01-01

    Much of our critical infrastructure is controlled by large software systems whose participants are distributed across the Internet. As our dependence on these critical systems continues to grow, it becomes increasingly important that they meet strict availability and performance requirements, even in the face of malicious attacks, including those…

  19. Heart Attack - Multiple Languages: MedlinePlus

    MedlinePlus

    ... List of All Topics All Heart Attack - Multiple Languages To use the sharing features on this page, please enable JavaScript. Arabic (العربية) Bosnian (Bosanski) Chinese - Simplified (简体中文) Chinese - Traditional ( ...

  20. Modified localized attack on complex network

    NASA Astrophysics Data System (ADS)

    Dong, Gaogao; Du, Ruijin; Hao, Huifang; Tian, Lixin

    2016-01-01

    Since a shell structure contains a wealth of information, it is not only very important for understanding the transport properties of the network, but also essential to identify influential spreaders in complex networks. Nodes within each shell can be classified into two categories: protected nodes and unprotected nodes. In this paper, we propose a generalization of the localized attack, modified localized attack, which means that when a randomly chosen node (root node) is under attack, protected nodes will not be removed, but unprotected nodes in the nearest shells will fail. We numerically and analytically study the system robustness under this attack by taking an Erdös-Rényi (ER) network, a regular random (RR) network and a scale-free (SF) network as examples. Moreover, a fraction of nodes belonging to giant component S and a critical threshold q c , where S approaches to zero, are given. The result implies that increasing connection density has been found to be useful to significantly improve network robustness.

  1. Responses to the September 11, 2001 Attacks.

    ERIC Educational Resources Information Center

    Anderson, Frances E.

    2001-01-01

    This editorial introduces a special section devoted to chronicling the responses of art therapists after the September 11th attacks. The section contains 10 articles from therapists in New York City, New Jersey, Long Island, Washington, DC, and California. Articles include stories of the reactions of the therapists as well as their work with…

  2. Union, States Wage Frontal Attack on NCLB

    ERIC Educational Resources Information Center

    Keller, Bess; Sack, Joetta L.

    2005-01-01

    Widespread sniping at the Bush administration's centerpiece education law escalated into a frontal attack as the nation's largest teachers' union. Several school districts sued federal officials over the measure, just a day after the Utah legislature approved a bill challenging the reach of the law. The National Education Association's suit…

  3. Adversarial Feature Selection Against Evasion Attacks.

    PubMed

    Zhang, Fei; Chan, Patrick P K; Biggio, Battista; Yeung, Daniel S; Roli, Fabio

    2016-03-01

    Pattern recognition and machine learning techniques have been increasingly adopted in adversarial settings such as spam, intrusion, and malware detection, although their security against well-crafted attacks that aim to evade detection by manipulating data at test time has not yet been thoroughly assessed. While previous work has been mainly focused on devising adversary-aware classification algorithms to counter evasion attempts, only few authors have considered the impact of using reduced feature sets on classifier security against the same attacks. An interesting, preliminary result is that classifier security to evasion may be even worsened by the application of feature selection. In this paper, we provide a more detailed investigation of this aspect, shedding some light on the security properties of feature selection against evasion attacks. Inspired by previous work on adversary-aware classifiers, we propose a novel adversary-aware feature selection model that can improve classifier security against evasion attacks, by incorporating specific assumptions on the adversary's data manipulation strategy. We focus on an efficient, wrapper-based implementation of our approach, and experimentally validate its soundness on different application examples, including spam and malware detection. PMID:25910268

  4. Method for detecting sophisticated cyber attacks

    SciTech Connect

    Potok, Thomas E.

    2008-11-18

    A method of analyzing computer intrusion detection information that looks beyond known attacks and abnormal access patterns to the critical information that an intruder may want to access. Unique target identifiers and type of work performed by the networked targets is added to audit log records. Analysis using vector space modeling, dissimilarity matrix comparison, and clustering of the event records is then performed.

  5. Survival of child after lion attack

    PubMed Central

    Dabdoub, Carlos F.; Dabdoub, Carlos B.; Chavez, Mario; Molina, Felipe

    2013-01-01

    Background: Injuries to humans caused by attacks from large predators are very rare, especially in the United States, Europe, or Latin America. A few cases were reported on accidents in zoos or animal farms, being very uncommon in children. The purposes of this report include describing the case of a child who sustained an attack by a lion named “Bang-Bang”, which resulted in injuries to the head, chest, and abdomen, as well as the subsequent neurosurgical treatment and providing a review of the literature. Case Description: We report the case of an 8-year-old boy who was attacked by a lion during a circus show. The patient underwent an emergent neurosurgical procedure, including parietal craniectomy, cleaning, and extensive surgical debridement of the wounds. Despite open severe head trauma with brain damage as well as thorax and abdomen trauma, the child survived, with minimal neurological sequelae. Conclusions: Human injury resulting from encounters with nondomesticated animals is increasingly rising throughout the world. This case highlights the potentially violent and aggressive nature of wild mammals held in captivity. Unusual wild animal attacks and the complex injuries that result may pose a challenge to surgeons practicing in resource-limited settings. In this sense, the best treatment in the mentioned case is the prevention of human injuries by these animals. In addition, to attend to these infrequent cases, the authors emphasize the importance of a multidisciplinary approach to achieve the best cosmetic and functional results. PMID:23869277

  6. Rhode Island School Terrorist Attack Preparedness

    ERIC Educational Resources Information Center

    Dube, Michael W. M.

    2012-01-01

    This study examined the state of safety and terrorist attack preparedness in Rhode Island Schools as determined by Rhode Island school leader perceptions. The study is descriptive in nature as it gathers data to describe a particular event or situation. Using a researcher generated survey based on terrorist preparedness guidelines and suggestions…

  7. Shark Attack! Sinking Your Teeth into Anatomy.

    ERIC Educational Resources Information Center

    House, Herbert

    2002-01-01

    Presents a real life shark attack story and studies arm reattachment surgery to teach human anatomy. Discusses how knowledge of anatomy can be put to use in the real world and how the arm functions. Includes teaching notes and suggestions for classroom management. (YDS)

  8. CASE STUDY: DIELDRIN ATTACK IN DALYAN LAGOON

    EPA Science Inventory

    During the first two weeks of December 2005, NATO sponsored an Advanced Study Institute (ASI) in Istanbul, Turkey. Part of this ASI involved a case study of a terrorist attack, where a chemical was assumed to be dumped into Sulunger Lake in Turkey. This chapter documents the re...

  9. Association between Terror Attacks and Suicide Attempts

    ERIC Educational Resources Information Center

    Weizman, Tal; Yagil, Yaron; Schreiber, Shaul

    2009-01-01

    Based on Durkheim's "Control theory," we explored the association between frequency of terror attacks in Israel and the frequency of suicide attempts admitted to the Emergency Room of a major general hospital in Tel-Aviv (1999-2004). Analysis of the six-year study period as a whole revealed no significant correlation between the variables, with…

  10. Plant defences against herbivore and insect attack

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants deploy a number of defences against attack by insects and other herbivores. Direct defence is conferred by plant products and structures that deter or kill the herbivores. Chemical toxins and deterrents vary widely among plant species, and some typical toxins include alkaloids, terpenoids, st...

  11. After Heart Attack, New Threat: Heart Failure

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159007.html After Heart Attack, New Threat: Heart Failure 1 in 4 survivors develops this serious ... TUESDAY, May 24, 2016 (HealthDay News) -- Risk of heart failure appears high within a few years of ...

  12. The buzzing of flies' wings

    NASA Astrophysics Data System (ADS)

    Easton, Don

    1999-02-01

    The object of this science-fair project was to determine the wing-beat frequency of common house flies from the frequency of the sound produced when they buzz their wings. The data produced a pattern that I have seen many times and felt sure that I knew what was going on. Like many interesting and seemingly simple phenomena, the longer that I look at this one the more intriguing and less explicable it becomes.

  13. Notes on flying and dying.

    PubMed

    Meyer, B C

    1983-07-01

    Focused on selected details in the lives and creative works of Samuel Johnson, Edgar Allan Poe, and Houdini, this paper explores a seeming antinomy between claustrophobic annihilation and aviation. At first glance the latter appears as an antidote to the threat of entrapment and death. On a deeper level the distinction fades as the impression arises that in the examples cited, flying may represent an unconscious expression of a wish for death and ultimate reunion. PMID:6351146

  14. America under attack: the "10 commandments" of responding to mass terrorist attacks.

    PubMed

    Everly, G S; Mitchell, J T

    2001-01-01

    On September 11, 2001 terrorist attacks caused the catastrophic collapse of the twin towers of the World Trade Center in New York City. Approximately 40 minutes after the World Trade Center was attacked, a similar terrorist attack was perpetrated against the Pentagon in Washington, D.C. Although the resultant physical devastation was beyond anything this nation has ever experienced, the psychological devastation may not be known for months, or even years. This paper discusses, not only a structure for understanding the phases of terrorism, but offers 10 recommendations for responding to acts of terrorism. PMID:11642190

  15. Motor control of fly feeding.

    PubMed

    McKellar, Claire E

    2016-06-01

    Following considerable progress on the molecular and cellular basis of taste perception in fly sensory neurons, the time is now ripe to explore how taste information, integrated with hunger and satiety, undergo a sensorimotor transformation to lead to the motor actions of feeding behavior. I examine what is known of feeding circuitry in adult flies from more than 250 years of work in larger flies and from newer work in Drosophila. I review the anatomy of the proboscis, its muscles and their functions (where known), its motor neurons, interneurons known to receive taste inputs, interneurons that diverge from taste circuitry to provide information to other circuits, interneurons from other circuits that converge on feeding circuits, proprioceptors that influence the motor control of feeding, and sites of integration of hunger and satiety on feeding circuits. In spite of the several neuron types now known, a connected pathway from taste inputs to feeding motor outputs has yet to be found. We are on the threshold of an era where these individual components will be assembled into circuits, revealing how nervous system architecture leads to the control of behavior. PMID:27309215

  16. Susceptibility of 15 mango (Sapindales: Anacardiaceae) cultivars to the attack by Anastrepha ludens and Anastrepha obliqua (Diptera: Tephritidae) and the role of underdeveloped fruit as pest reservoirs: management implications.

    PubMed

    Aluja, M; Arredondo, J; Díaz-Fleischer, F; Birke, A; Rull, J; Niogret, J; Epsky, N

    2014-02-01

    We evaluated the susceptibility of 15 mango cultivars to the attack of Anastrepha ludens (Loew) and Anastrepha obliqua (Macquart) (Diptera: Tephritidae), the main tephritid pests of this crop in Mexico. In a field experiment, bagged fruit-bearing branches were exposed to gravid females of both fly species. Infestation rates, developmental time, adult eclosion, and F1 adult longevity, fecundity, and fertility were recorded, ranking cultivars in terms of susceptibility to fly attack and development. We also compared the volatile profile in selected resistant and susceptible cultivars in search of possible correlations. In a second experiment, clutch size for A. ludens was determined in each cultivar. Infestation rates, developmental time, and F1 demographic parameters varied sharply among cultivars and between fly species for bagged fruit. Cultivars 'Vishi,' '74-82,' and 'Brooks' were most susceptible to A. ludens infestation while "Tommy,' 'Sensation,' and 'Ataulfo "niño"' (parthenocarpic fruit) were most susceptible to A. obliqua infestation. 'Edward,' 'Kent,' 'Brooks late,' 'Palmer, and 'Ataulfo' exhibited tolerance to attack of both fly species. Fruit of susceptible and resistant cultivars exhibited unique volatile profiles. Fly development and F1 adult demographic parameters varied significantly among cultivars. A. ludens females laid larger clutches in larger and harder fruit. We highlight the important role of Ataulfo "niño" as pest reservoir if fruit is left unharvested on trees. We discuss the possible use of highly resistant cultivars as trap crops or egg sinks. PMID:24665723

  17. Computational Aerodynamic Analysis of a Micro-CT Based Bio-Realistic Fruit Fly Wing

    PubMed Central

    Brandt, Joshua; Doig, Graham; Tsafnat, Naomi

    2015-01-01

    The aerodynamic features of a bio-realistic 3D fruit fly wing in steady state (snapshot) flight conditions were analyzed numerically. The wing geometry was created from high resolution micro-computed tomography (micro-CT) of the fruit fly Drosophila virilis. Computational fluid dynamics (CFD) analyses of the wing were conducted at ultra-low Reynolds numbers ranging from 71 to 200, and at angles of attack ranging from -10° to +30°. It was found that in the 3D bio-realistc model, the corrugations of the wing created localized circulation regions in the flow field, most notably at higher angles of attack near the wing tip. Analyses of a simplified flat wing geometry showed higher lift to drag performance values for any given angle of attack at these Reynolds numbers, though very similar performance is noted at -10°. Results have indicated that the simplified flat wing can successfully be used to approximate high-level properties such as aerodynamic coefficients and overall performance trends as well as large flow-field structures. However, local pressure peaks and near-wing flow features induced by the corrugations are unable to be replicated by the simple wing. We therefore recommend that accurate 3D bio-realistic geometries be used when modelling insect wings where such information is useful. PMID:25954946

  18. Error and attack vulnerability of temporal networks

    NASA Astrophysics Data System (ADS)

    Trajanovski, S.; Scellato, S.; Leontiadis, I.

    2012-06-01

    The study of real-world communication systems via complex network models has greatly expanded our understanding on how information flows, even in completely decentralized architectures such as mobile wireless networks. Nonetheless, static network models cannot capture the time-varying aspects and, therefore, various temporal metrics have been introduced. In this paper, we investigate the robustness of time-varying networks under various failures and intelligent attacks. We adopt a methodology to evaluate the impact of such events on the network connectivity by employing temporal metrics in order to select and remove nodes based on how critical they are considered for the network. We also define the temporal robustness range, a new metric that quantifies the disruption caused by an attack strategy to a given temporal network. Our results show that in real-world networks, where some nodes are more dominant than others, temporal connectivity is significantly more affected by intelligent attacks than by random failures. Moreover, different intelligent attack strategies have a similar effect on the robustness: even small subsets of highly connected nodes act as a bottleneck in the temporal information flow, becoming critical weak points of the entire system. Additionally, the same nodes are the most important across a range of different importance metrics, expressing the correlation between highly connected nodes and those that trigger most of the changes in the optimal information spreading. Contrarily, we show that in randomly generated networks, where all the nodes have similar properties, random errors and intelligent attacks exhibit similar behavior. These conclusions may help us in design of more robust systems and fault-tolerant network architectures.

  19. Recovery of human remains after shark attack.

    PubMed

    Byard, Roger W; James, Ross A; Heath, Karen J

    2006-09-01

    Two cases of fatal shark attack are reported where the only tissues recovered were fragments of lung. Case 1: An 18-year-old male who was in the sea behind a boat was observed by friends to be taken by a great white shark (Carcharodon carcharias). The shark dragged him under the water and then, with a second shark, dismembered the body. Witnesses noted a large amount of blood and unrecognizable body parts coming to the surface. The only tissues recovered despite an intensive beach and sea search were 2 fragments of lung. Case 2: A 19-year-old male was attacked by a great white shark while diving. A witness saw the shark swim away with the victim's body in its mouth. Again, despite intensive beach and sea searches, the only tissue recovered was a single piece of lung, along with pieces of wetsuit and diving equipment. These cases indicate that the only tissue to escape being consumed or lost in fatal shark attacks, where there is a significant attack with dismemberment and disruption of the integrity of the body, may be lung. The buoyancy of aerated pulmonary tissue ensures that it rises quickly to the surface, where it may be recovered by searchers soon after the attack. Aeration of the lung would be in keeping with death from trauma rather than from drowning and may be a useful marker in unwitnessed deaths to separate ante- from postmortem injury, using only relatively small amounts of tissues. Early organ recovery enhances the identification of human tissues as the extent of morphologic alterations by putrefactive processes and sea scavengers will have been minimized. DNA testing is also possible on such recovered fragments, enabling confirmation of the identity of the victim. PMID:16936505

  20. House fly oviposition inhibition by larvae ofHermetia illucens, the black soldier fly.

    PubMed

    Bradley, S W; Sheppard, D C

    1984-06-01

    Wild populations of house flies were inhibited from ovipositing into poultry manure containing larvae of the black soldier fly,Hermetia illucens (L.). A laboratory strain of house fly responded differently, readily ovipositing into manure with lower densities of soldier fly larvae, but avoiding the higher densities tested. The amount of timeH. illucens larvae occupy the manure prior to an oviposition test influences ovipositional responses of house flies. Manure conditioned byH. illucens larvae for 4-5 days did not significantly inhibit house fly oviposition. We suggest that some type of interspecific chemical communication (allomone) is present. PMID:24318779

  1. Identifying glass compositions in fly ash

    NASA Astrophysics Data System (ADS)

    Aughenbaugh, Katherine; Stutzman, Paul; Juenger, Maria

    2016-01-01

    In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS), calcium aluminosilicate glasses (CAS), a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  2. Can leek interfere with bean plant-bean fly interaction? Test of ecological pest management in mixed cropping.

    PubMed

    Bandara, K A N P; Kumar, V; Ninkovic, V; Ahmed, E; Pettersson, J; Glinwood, R

    2009-06-01

    Effects of volatile odors from leek, Allium porum L., on the behavior of bean fly, Ophiomyia phaseoli (Tryon) (Diptera: Agromyzidae), were tested in laboratory olfactometer bioassays. Aqueous and solvent extracts (dichloromethane and methanol) of leek were repellent to adult flies. Whole leek plants were repellent and prevented attraction to the host plant, beans. Beans that had been exposed to volatiles from living leek plants for 7 d became repellent to the fly. Leek and several other crops were tested in field experiments to identify candidate crops for a mixed cropping system to minimize bean fly attack in beans, Phaseolus vulgaris L. In a wet season field experiment, mixed cropping of bean with leek or three other vegetable crops did not significantly reduce bean fly infestation or infection with Fusarium oxysporum Schltdl. compared with a mono crop, but significantly reduced plant death caused by both agents combined. In two dry season field experiments, mixed cropping of beans with leek significantly reduced adult bean fly settling, emergence, and death of bean plants compared with a mono crop. Bean yield per row was approximately 150% higher for the mixed crop, and economic returns were approximately Sri Lankan Rs. 180,000/ha, higher than for the mono crop. For the mono crop, the farmer had a monetary loss, which would become a small profit only if the costs of family labor are excluded. The study is an example of the first steps toward development of sustainable plant protection in a subsistence system. PMID:19610413

  3. Chilling and Host Plant/Site-Associated Eclosion Times of Western Cherry Fruit Fly (Diptera: Tephritidae) and a Host-Specific Parasitoid.

    PubMed

    Yee, Wee L; Goughnour, Robert B; Hood, Glen R; Forbes, Andrew A; Feder, Jeffrey L

    2015-08-01

    The western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), is an endemic herbivore of bitter cherry, Prunus emarginata (Douglas ex Hooker) Eaton, but ∼100 years ago established on earlier-fruiting domesticated sweet cherry, Prunus avium (L.) L. Here, we determined if eclosion times of adult R. indifferens from sweet and bitter cherry differ according to the phenology of their respective host plants and if eclosion times of the host-specific parasitoid Diachasma muliebre (Muesebeck) (Hymenoptera: Braconidae) attacking bitter and sweet cherry flies differ according to the eclosion phenology of their fly hosts. Fly pupae from sweet and bitter cherry fruit were collected from sympatric and allopatric sites in Washington state, and chilled at 5°C. Because timing of eclosion in R. indifferens depends on chill duration, eclosion time in wasps could also vary with chill duration. To account for this, fly pupae were chilled for 1, 2, 2.5, 3, 4, 6, or 8 mo. Both flies and wasps eclosed earlier with longer chill durations. Eclosion times of sweet and bitter cherry flies from a sympatric site in central Washington did not differ. However, at allopatric sites in northwestern and central Washington, bitter cherry flies eclosed later than sweet and bitter cherry flies at the sympatric site. Correspondingly, D. muliebre parasitizing a more isolated bitter cherry fly population eclosed later than D. muliebre parasitizing earlier-emerging sweet and bitter cherry fly populations. These results provide evidence for D. muliebre rapidly responding to changes in host plant shifts by R. indifferens. PMID:26314048

  4. Ultrasonic Vocalizations Emitted by Flying Squirrels

    PubMed Central

    Murrant, Meghan N.; Bowman, Jeff; Garroway, Colin J.; Prinzen, Brian; Mayberry, Heather; Faure, Paul A.

    2013-01-01

    Anecdotal reports of ultrasound use by flying squirrels have existed for decades, yet there has been little detailed analysis of their vocalizations. Here we demonstrate that two species of flying squirrel emit ultrasonic vocalizations. We recorded vocalizations from northern (Glaucomys sabrinus) and southern (G. volans) flying squirrels calling in both the laboratory and at a field site in central Ontario, Canada. We demonstrate that flying squirrels produce ultrasonic emissions through recorded bursts of broadband noise and time-frequency structured frequency modulated (FM) vocalizations, some of which were purely ultrasonic. Squirrels emitted three types of ultrasonic calls in laboratory recordings and one type in the field. The variety of signals that were recorded suggest that flying squirrels may use ultrasonic vocalizations to transfer information. Thus, vocalizations may be an important, although still poorly understood, aspect of flying squirrel social biology. PMID:24009728

  5. Ultrasonic vocalizations emitted by flying squirrels.

    PubMed

    Murrant, Meghan N; Bowman, Jeff; Garroway, Colin J; Prinzen, Brian; Mayberry, Heather; Faure, Paul A

    2013-01-01

    Anecdotal reports of ultrasound use by flying squirrels have existed for decades, yet there has been little detailed analysis of their vocalizations. Here we demonstrate that two species of flying squirrel emit ultrasonic vocalizations. We recorded vocalizations from northern (Glaucomys sabrinus) and southern (G. volans) flying squirrels calling in both the laboratory and at a field site in central Ontario, Canada. We demonstrate that flying squirrels produce ultrasonic emissions through recorded bursts of broadband noise and time-frequency structured frequency modulated (FM) vocalizations, some of which were purely ultrasonic. Squirrels emitted three types of ultrasonic calls in laboratory recordings and one type in the field. The variety of signals that were recorded suggest that flying squirrels may use ultrasonic vocalizations to transfer information. Thus, vocalizations may be an important, although still poorly understood, aspect of flying squirrel social biology. PMID:24009728

  6. Two fatal tiger attacks in zoos.

    PubMed

    Tantius, Britta; Wittschieber, Daniel; Schmidt, Sven; Rothschild, Markus A; Banaschak, Sibylle

    2016-01-01

    Two captive tiger attacks are presented that took place in Cologne and Münster zoos. Both attacks occurred when the handlers, intent on cleaning the enclosures, entered whilst the tigers accidently retained access to the location, and thus defended their territory against the perceived intruders. Both victims suffered fatal neck injuries from the bites. At Münster, colleagues managed to lure the tiger away from its victim to enable treatment, whilst the Cologne zoo tiger had to be shot in order to allow access to be gained. Whilst it was judged that human error led to the deaths of the experienced zookeepers, the investigation in Münster was closed as no third party was found to be at fault, whereas the Cologne zoo director was initially charged with being negligent. These charges were subsequently dismissed as safety regulations were found to be up to date. PMID:26115644

  7. Cell phone camera ballistics: attacks and countermeasures

    NASA Astrophysics Data System (ADS)

    Steinebach, Martin; Liu, Huajian; Fan, Peishuai; Katzenbeisser, Stefan

    2010-01-01

    Multimedia forensics deals with the analysis of multimedia data to gather information on its origin and authenticity. One therefore needs to distinguish classical criminal forensics (which today also uses multimedia data as evidence) and multimedia forensics where the actual case is based on a media file. One example for the latter is camera forensics where pixel error patters are used as fingerprints identifying a camera as the source of an image. Of course multimedia forensics can become a tool for criminal forensics when evidence used in a criminal investigation is likely to be manipulated. At this point an important question arises: How reliable are these algorithms? Can a judge trust their results? How easy are they to manipulate? In this work we show how camera forensics can be attacked and introduce a potential countermeasure against these attacks.

  8. Satellite Threat Warning and Attack Reporting

    SciTech Connect

    Hilland, D.; Phipps, G.; Jingle, C.; Newton, G.

    1997-12-31

    The Air Force Research Laboratory`s Satellite Threat Warning and Attack Reporting (STW/AR) program will provide technologies for advanced threat warning and reporting of radio frequency (RF) and laser threats. The STW/AR program objectives are: (a) develop cost- effective technologies to detect, identify, locate, characterize, and report attacks or interference against U.S. and Allied satellites. (b) demonstrate innovative, light-weight, low-power, laser and RF sensors. The program focuses on the demonstration of RF and laser sensors. The RF sensor effort includes the investigation of interferometric antenna arrays, multi-arm spiral and butler matrix antennas, wideband receivers, adaptive processors, and improved processing algorithms. The laser sensor effort includes the investigation of alternative detectors, broadband grating and optical designs, active pixel sensing, and improved processing algorithms.

  9. RISK DISCLOSURE AGAINST ATTACK ON CRITICAL INFRASTRUCTURES

    NASA Astrophysics Data System (ADS)

    Yoshida, Mamoru; Kobayashi, Kiyoshi

    This paper analyzes the government's defensive and disclosure strategies to reduce the damage caused by terrorists that attack critical infrastructures using subjective game theory. The government recognizes a terrorist as a hidden opponent and the government's decision making about the policies against terror attacks depends on the belief about the existence of terrorist. In addition, it is not necessarily true that the government and the terrorist play the common game and make their decisions. Considering these points, the paper formulates the model in which the government and the terrorist formulate the subjective games respectively, and they induce the strategies using the equilibriums of their subjective games. The paper concluded that the government's disclosure about the implementation of the countermeasure, rather than the disclosure of warning level related with the belief about the existence of terrorist, brings about the higher increment of the subjective payoffs of the government.

  10. Making MANET secured against malicious attack

    NASA Astrophysics Data System (ADS)

    Kush, Ashwani; Taneja, Sunil; Kush, Shagun

    2011-12-01

    A Mobile Adhoc Network (MANET) is characterized by mobile nodes, multihop wireless connectivity, infrastructureless environment and dynamic topology. A recent trend in Ad Hoc network routing is the reactive ondemand philosophy where routes are established only when required. Stable Routing is of major concern in Ad hoc routing. Security and Power efficiency are the major concerns in this field. This paper is an effort to use security to achieve more reliable routing. The ad hoc environment is accessible to both legitimate network users and malicious attackers. The proposed scheme is intended to incorporate security aspect on existing protocols. The study will help in making protocol more robust against attacks to achieve stable routing in routing protocols.

  11. Mitigation of malicious attacks on networks

    PubMed Central

    Schneider, Christian M.; Moreira, André A.; Andrade, José S.; Havlin, Shlomo; Herrmann, Hans J.

    2011-01-01

    Terrorist attacks on transportation networks have traumatized modern societies. With a single blast, it has become possible to paralyze airline traffic, electric power supply, ground transportation or Internet communication. How and at which cost can one restructure the network such that it will become more robust against a malicious attack? We introduce a new measure for robustness and use it to devise a method to mitigate economically and efficiently this risk. We demonstrate its efficiency on the European electricity system and on the Internet as well as on complex networks models. We show that with small changes in the network structure (low cost) the robustness of diverse networks can be improved dramatically whereas their functionality remains unchanged. Our results are useful not only for improving significantly with low cost the robustness of existing infrastructures but also for designing economically robust network systems. PMID:21368159

  12. Mitigation of malicious attacks on networks.

    PubMed

    Schneider, Christian M; Moreira, André A; Andrade, José S; Havlin, Shlomo; Herrmann, Hans J

    2011-03-01

    Terrorist attacks on transportation networks have traumatized modern societies. With a single blast, it has become possible to paralyze airline traffic, electric power supply, ground transportation or Internet communication. How and at which cost can one restructure the network such that it will become more robust against a malicious attack? We introduce a new measure for robustness and use it to devise a method to mitigate economically and efficiently this risk. We demonstrate its efficiency on the European electricity system and on the Internet as well as on complex networks models. We show that with small changes in the network structure (low cost) the robustness of diverse networks can be improved dramatically whereas their functionality remains unchanged. Our results are useful not only for improving significantly with low cost the robustness of existing infrastructures but also for designing economically robust network systems. PMID:21368159

  13. Use Of Fly Iarvae In Space Agriculture

    NASA Astrophysics Data System (ADS)

    Katayama, Naomi; Mitsuhashi, Jun; Hachiya, Natumi; Miyashita, Sachiko; Hotta, Atuko

    The concept of space agriculture is full use of biological and ecological components ot drive materials recycle loop. In an ecological system, producers, consumers and decomposers are its member. At limited resources acailable for space agriculture, full use of members' function is required to avoid food shortage and catastrophe.Fly is categrized to a decomposer at its eating excreta and rotten materials. However, is it could be edible, certainly it is eaten in several food culture of the world, it functions as a converter of inedible biomass ot edible substance. This conversion enhances the efficiency of usage of resource that will be attributed to space agriculture. In this context, we examine the value of melon fly, Dacus cucurbitae, as a candidate fly species ofr human food. Nutrients in 100g of melon fly larvae were protein 12g, lipid 4.6g Fe 4.74mg, Ca 275mg, Zn 6.37mg, Mn 4.00mg. Amino acids compositon in 100g of larvae was glutamic acid 1.43g and aspartic acid 1.12g. Because of high contents of these amino acids taste of fly larva might be good. Life time of adult melon fly is one to two month, and lays more than 1,000 eggs in total during the life. Larvae hatch after one to two days, and metamorphose after 8 to 15 days to pupae. Srxual maturity is reached after 22 days the earliest from it egg. Sixteen generations could be succeeded in a year for melon fly at maximum. The rate of proliferation of fly is quite high compared to silkworm that can have 8.7 generations per year. The wide food habit of fly, compared to mulberry leaf for silkworm, is another advantage to choose fly for entomophage. Rearing technology of melon fly is well established, since large scaled production of sterile male fly has been conducted in order ot exterminate melon fly in the field. Feeding substance for melon fly larvae in production line is a mixture of wheat, bran, raw sugar, olara, beer yeast, tissue paper, and additive chemicals. A 1 kg of feed substance can be converted to

  14. Passive Baited Sequential Filth Fly Trap.

    PubMed

    Aldridge, Robert L; Britch, Seth C; Snelling, Melissa; Gutierez, Arturo; White, Gregory; Linthicum, Kenneth J

    2015-09-01

    Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted-cone design to passively confine flies in 8 modified collection bottles corresponding to 8 intervals. Efficacy trials in a hot-arid desert environment indicate no significant difference (P  =  0.896) between the modified sequential trap and a Rid-Max® fly trap. PMID:26375911

  15. Gaps in Care Can Harm Patients After Heart Attack

    MedlinePlus

    ... html Gaps in Care Can Harm Patients After Heart Attack Waiting too long for first medical apppointment after ... 23, 2016 WEDNESDAY, March 23, 2016 (HealthDay News) -- Heart attack patients who wait a long period to have ...

  16. Brain Scans Give Clues to Stress-Heart Attack Link

    MedlinePlus

    ... 157945.html Brain Scans Give Clues to Stress-Heart Attack Link Fear appears to increase inflammation in the ... stress is linked to an increased risk of heart attack and stroke. Increased activity in the amygdala -- the ...

  17. Heart Attack Before 50 Ups Early Death Risk

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_160692.html Heart Attack Before 50 Ups Early Death Risk But healthy ... News) -- The risk of early death after a heart attack has lessened over the past 30 years among ...

  18. Sex Suffers for Younger Adults After Heart Attack

    MedlinePlus

    ... 160722.html Sex Suffers for Younger Adults After Heart Attack Lack of interest a complaint of many women ... WEDNESDAY, Aug. 31, 2016 (HealthDay News) -- After a heart attack, many younger adults experience sexual difficulties -- and women ...

  19. Heart Attack Help? There's an App for That

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159504.html Heart Attack Help? There's an App for That Emergency medicine ... American Heart Association. When someone is suffering a heart attack, stroke or cardiac arrest, quick action can be ...

  20. Nonlinear optical cryptosystem resistant to standard and hybrid attacks

    NASA Astrophysics Data System (ADS)

    Sinha, Aloka

    2016-06-01

    We propose a nonlinear optical cryptosystem that is resistant to amplitude-phase retrieval attacks, known-plaintext attack and chosen-plaintext attack. A squaring operation is introduced in the encryption path, which thwarts the iterative attacks. This nonlinear operation tends to amplify the error in the estimation during an iterative attack. The decryption process requires the use of a square-root operation. Thus, in the reverse path also, the attacks encounter the nonlinear square-root operation. These two nonlinearities make the iterative attacks unstable, thereby leading to non-convergence of the mean square error (MSE). Our technique is also resistant to hybrid attacks. The technique is general and is shown to work on a variety of images of the type grayscale and binary. Numerical simulation results corroborate the effectiveness of the proposed cryptosystem.

  1. Black Heart Attack Victims More Likely to Have Ambulance Diverted

    MedlinePlus

    ... nih.gov/medlineplus/news/fullstory_157879.html Black Heart Attack Victims More Likely to Have Ambulance Diverted Study ... 2016 MONDAY, March 21, 2016 (HealthDay News) -- Black heart attack patients are more likely than whites to have ...

  2. Heart Attack - Multiple Languages: MedlinePlus

    MedlinePlus

    ... French (français) Hindi (हिन्दी) Korean (한국어) Portuguese (português) Russian (Русский) Somali (af Soomaali) Spanish (español) Tagalog ( ... 한국어 (Korean) Bilingual PDF Health Information Translations Portuguese (português) Heart Attack Ataque Cardíaco - português (Portuguese) Bilingual PDF ...

  3. Securing iris recognition systems against masquerade attacks

    NASA Astrophysics Data System (ADS)

    Galbally, Javier; Gomez-Barrero, Marta; Ross, Arun; Fierrez, Julian; Ortega-Garcia, Javier

    2013-05-01

    A novel two-stage protection scheme for automatic iris recognition systems against masquerade attacks carried out with synthetically reconstructed iris images is presented. The method uses different characteristics of real iris images to differentiate them from the synthetic ones, thereby addressing important security flaws detected in state-of-the-art commercial systems. Experiments are carried out on the publicly available Biosecure Database and demonstrate the efficacy of the proposed security enhancing approach.

  4. Cryptogenic Drop Attacks: An Affliction of Women

    PubMed Central

    Stevens, D. L.; Matthews, W. B.

    1973-01-01

    A drop attack was defined as falling without warning, not apparently due to any malfunction of the legs, not induced by change of posture or movement of the head, and not accompanied by vertigo or other cephalic sensation. All 33 patients attending a neurological clinic with a primary complaint fulfilling these criteria were women, and a further seven examples were found by questioning 200 consecutive patients at a gynaecological clinic. No affected male was found. In all but one patient, falls occurred only when walking. They were not due to wearing high-heeled shoes. The average age at onset was 44·5 years and in younger women onset was often during pregnancy. The accepted causes of drop attacks were not found with certainty in any of these patients. The sex incidence and the circumstances of the falls suggest that the cause may lie in differences between the two sexes in the mechanism of walking rather than in any central disturbance. Drop attacks in women commonly occur as an isolated symptom for many years, and although distressing have no serious prognostic implications. PMID:4689829

  5. Ruptured Globe due to a Bird Attack

    PubMed Central

    Abdulla, Haitham A.; Alkhalifa, Saad K.

    2016-01-01

    Introduction Bird attacks are in general an uncommon event. To our knowledge, this is the first reported case in Bahrain. There have been very few cases reported worldwide. Mainly, birds attack humans as retaliation to threats surrounding their environment. At certain occasions, bird attack frequency increases especially during mating season or in the presence of a threat toward their young. Methods A 31-year-old male presented with a history of left-eye trauma, loss of vision, pain and tearing for 2 hours. A left corneal penetrating laceration and traumatic cataract were diagnosed. The corneal laceration was closed surgically, the lens was aspirated and anterior vitrectomy performed. Results After 4 months of follow-up, penetrating keratoplasty and posterior chamber intraocular lens implantation were performed elsewhere. The patient's vision improved from hand motion in his left eye to 20/200 without correction. Conclusion Corneal perforation secondary to a bird injury can be treated successfully with surgical closure and broad intravenous antibiotic coverage. This rare type of ocular trauma does not require any specific additional measures. PMID:27293411

  6. Enhancing network robustness against malicious attacks.

    PubMed

    Zeng, An; Liu, Weiping

    2012-06-01

    In a recent work [Schneider et al., Proc. Natl. Acad. Sci. USA 108, 3838 (2011)], the authors proposed a simple measure for network robustness under malicious attacks on nodes. Using a greedy algorithm, they found that the optimal structure with respect to this quantity is an onion structure in which high-degree nodes form a core surrounded by rings of nodes with decreasing degree. However, in real networks the failure can also occur in links such as dysfunctional power cables and blocked airlines. Accordingly, complementary to the node-robustness measurement (R(n)), we propose a link-robustness index (R(l)). We show that solely enhancing R(n) cannot guarantee the improvement of R(l). Moreover, the structure of an R(l)-optimized network is found to be entirely different from that of an onion network. In order to design robust networks that are resistant to a more realistic attack condition, we propose a hybrid greedy algorithm that takes both the R(n) and R(l) into account. We validate the robustness of our generated networks against malicious attacks mixed with both nodes and links failure. Finally, some economical constraints for swapping the links in real networks are considered, and significant improvement in both aspects of robustness is still achieved. PMID:23005185

  7. Enhancing network robustness against malicious attacks

    NASA Astrophysics Data System (ADS)

    Zeng, An; Liu, Weiping

    2012-06-01

    In a recent work [Schneider , Proc. Natl. Acad. Sci. USAPNASA60027-842410.1073/pnas.1009440108 108, 3838 (2011)], the authors proposed a simple measure for network robustness under malicious attacks on nodes. Using a greedy algorithm, they found that the optimal structure with respect to this quantity is an onion structure in which high-degree nodes form a core surrounded by rings of nodes with decreasing degree. However, in real networks the failure can also occur in links such as dysfunctional power cables and blocked airlines. Accordingly, complementary to the node-robustness measurement (Rn), we propose a link-robustness index (Rl). We show that solely enhancing Rn cannot guarantee the improvement of Rl. Moreover, the structure of an Rl-optimized network is found to be entirely different from that of an onion network. In order to design robust networks that are resistant to a more realistic attack condition, we propose a hybrid greedy algorithm that takes both the Rn and Rl into account. We validate the robustness of our generated networks against malicious attacks mixed with both nodes and links failure. Finally, some economical constraints for swapping the links in real networks are considered, and significant improvement in both aspects of robustness is still achieved.

  8. Formation Flying and Deformable Instruments

    SciTech Connect

    Rio, Yvon

    2009-05-11

    Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

  9. Fly-by-Wireless Update

    NASA Technical Reports Server (NTRS)

    Studor, George

    2010-01-01

    The presentation reviews what is meant by the term 'fly-by-wireless', common problems and motivation, provides recent examples, and examines NASA's future and basis for collaboration. The vision is to minimize cables and connectors and increase functionality across the aerospace industry by providing reliable, lower cost, modular, and higher performance alternatives to wired data connectivity to benefit the entire vehicle/program life-cycle. Focus areas are system engineering and integration methods to reduce cables and connectors, vehicle provisions for modularity and accessibility, and a 'tool box' of alternatives to wired connectivity.

  10. Blue versus Red: Towards a Model of Distributed Security Attacks

    NASA Astrophysics Data System (ADS)

    Fultz, Neal; Grossklags, Jens

    We develop a two-sided multiplayer model of security in which attackers aim to deny service and defenders strategize to secure their assets. Attackers benefit from the successful compromise of target systems, however, may suffer penalties for increased attack activities. Defenders weigh the force of an attack against the cost of security. We consider security decision-making in tightly and loosely coupled networks and allow defense expenditures in protection and self-insurance technologies.

  11. Study on the principle and defense of buffer overflow attacks

    NASA Astrophysics Data System (ADS)

    Lin, Wang

    2013-03-01

    Buffer overflow attacks have been the most common form in the network attacks and become a predominant problem in the system and network security area. With specific programs, this paper describes in detail the type of buffer overflow attacks and technical principles, so we have a good understanding of them, and then gives several common preventive measures.

  12. Assessing Terrorist Motivations for Attacking Critical Infrastructure

    SciTech Connect

    Ackerman, G; Abhayaratne, P; Bale, J; Bhattacharjee, A; Blair, C; Hansell, L; Jayne, A; Kosal, M; Lucas, S; Moran, K; Seroki, L; Vadlamudi, S

    2006-12-04

    Certain types of infrastructure--critical infrastructure (CI)--play vital roles in underpinning our economy, security and way of life. These complex and often interconnected systems have become so ubiquitous and essential to day-to-day life that they are easily taken for granted. Often it is only when the important services provided by such infrastructure are interrupted--when we lose easy access to electricity, health care, telecommunications, transportation or water, for example--that we are conscious of our great dependence on these networks and of the vulnerabilities that stem from such dependence. Unfortunately, it must be assumed that many terrorists are all too aware that CI facilities pose high-value targets that, if successfully attacked, have the potential to dramatically disrupt the normal rhythm of society, cause public fear and intimidation, and generate significant publicity. Indeed, revelations emerging at the time of this writing about Al Qaida's efforts to prepare for possible attacks on major financial facilities in New York, New Jersey, and the District of Columbia remind us just how real and immediate such threats to CI may be. Simply being aware that our nation's critical infrastructure presents terrorists with a plethora of targets, however, does little to mitigate the dangers of CI attacks. In order to prevent and preempt such terrorist acts, better understanding of the threats and vulnerabilities relating to critical infrastructure is required. The Center for Nonproliferation Studies (CNS) presents this document as both a contribution to the understanding of such threats and an initial effort at ''operationalizing'' its findings for use by analysts who work on issues of critical infrastructure protection. Specifically, this study focuses on a subsidiary aspect of CI threat assessment that has thus far remained largely unaddressed by contemporary terrorism research: the motivations and related factors that determine whether a terrorist

  13. Assembly States of FliM and FliG within the Flagellar Switch Complex

    PubMed Central

    Sircar, Ria; Borbat, Peter P.; Lynch, Michael J.; Bhatnagar, Jaya; Beyersdorf, Matthew S.; Halkides, Christopher J.; Freed, Jack H.; Crane, Brian R.

    2015-01-01

    At the base of the bacterial flagella a cytoplasmic rotor (the C-ring) generates torque and reverses rotation sense in response to stimuli. The bulk of the C-ring forms from many copies of the proteins FliG, FliM, and FliN, which together constitute the switch complex. To help resolve outstanding issues regarding C-ring architecture, interactions between FliM and FliG from Thermotoga maritima have been investigated with x-ray crystallography and pulsed dipolar electron spin resonance spectroscopy (PDS). A new crystal structure of an 11-unit FliG:FliM complex produces a large arc with a curvature consistent with the dimensions of the C-ring. Previously determined structures along with this new structure provided a basis to test switch complex assembly models. PDS combined with mutational studies and targeted cross-linking reveal that FliM and FliG interact through their middle domains to form both parallel and antiparallel arrangements in solution. Residue substitutions at predicted interfaces disrupt higher-order complexes that are primarily mediated by contacts between the C-terminal domain of FliG and the middle domain of a neighboring FliG molecule. Spin separations among multi-labeled component proteins fit to a self-consistent model that agrees well with electron microscopy images of the C-ring. An activated form of the response regulator CheY destabilizes the parallel arrangement of FliM molecules to perturb FliG alignment in a process that may reflect the onset of rotation switching. This data suggest a model of C-ring assembly in which intermolecular contacts among FliG domains provide a template for FliM assembly and cooperative transitions. PMID:25536293

  14. Testing for Mutagens Using Fruit Flies.

    ERIC Educational Resources Information Center

    Liebl, Eric C.

    1998-01-01

    Describes a laboratory employed in undergraduate teaching that uses fruit flies to test student-selected compounds for their ability to cause mutations. Requires no prior experience with fruit flies, incorporates a student design component, and employs both rigorous controls and statistical analyses. (DDR)

  15. Biological Control of Olive Fruit Fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestication of olive fruit, Olea europaea L., produced a better host for olive fruit fly, Bactrocera oleae (Gmelin), than wild olives, but fruit domestication reduced natural enemy efficiency. Important factors for selection of natural enemies for control of olive fruit fly include climate matchi...

  16. 14 CFR 121.549 - Flying equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flying equipment. 121.549 Section 121.549 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.549 Flying equipment. (a) The pilot...

  17. 14 CFR 121.549 - Flying equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flying equipment. 121.549 Section 121.549 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.549 Flying equipment. (a) The pilot...

  18. Passive Baited Sequential Filth Fly Trap

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted cone design to passively confi...

  19. FATE OF INHALED FLY ASH IN HAMSTERS

    EPA Science Inventory

    To determine pulmonary deposition, translocation, and clearance of inhaled fly ash, hamsters received a single 95-min nose-only exposure to neutron-activated fly ash. Over a period of 99 days postexposure, the hamsters were sacrificed in groups of six animals. Lungs, liver, kidne...

  20. Heavy metals leaching in Indian fly ash.

    PubMed

    Prasad, Bably; Mondal, Kajal Kumar

    2008-04-01

    Fly ash is an industrial waste generated from thermal power plants. Fly ash constitutes 80-85% of the total ash produced. A small part of fly ash is utilised in some sectors such as construction materials, building engineering, road, back fill, agriculture, selective engineering and processing useful materials. A large part of fly ash produced is disposed of with very high environmental risk. In the present paper, laboratory leaching test has been used to determine the potential mobility of Pb, Cd, Cr, Cu, Zn, Fe, Mn and Ni in fly ash samples, collected from Chandrapura Thermal Power Plant, Jharkhand and Ramagundam Super Thermal Power Plant, Andhra Pradesh, in order to assess their leachability when these wastes are disposed of. A cascade-leaching test was used at liquid-to-solid ratio (L/S) ranging between 20 and 100. Both fly ash samples exhibited neutral reactions, as indicated by pH values <11.75 and >7.0 at L/S=10 and contact time of 10 minutes. The percentage of leached amounts found to follow the trend Zn>Fe>Mn>Cr>Pb>Cu>Ni>Cd for fly ash from Chandrapura and Fe>Zn>Cu>Mn>Cr>Ni>Pb>Cd for fly ash from Ramagundam. Effect of pH on metals released from ash surface in aqueous solution followed a predictable pattern of decreasing release with increasing pH. PMID:19295096

  1. Neoplasms identified in free-flying birds

    USGS Publications Warehouse

    Siegfried, L.M.

    1983-01-01

    Nine neoplasms were identified in carcasses of free-flying wild birds received at the National Wildlife Health Laboratory; gross and microscopic descriptions are reported herein. The prevalence of neoplasia in captive and free-flying birds is discussed, and lesions in the present cases are compared with those previously described in mammals and birds.

  2. Neuroscience: Hunger Pangs in the Fly Brain.

    PubMed

    Schoofs, Andreas; Pankratz, Michael J

    2016-08-01

    Which neurons in the brain become engaged when the body is deprived of food? A new study addresses this question using the vinegar fly Drosophila melanogaster, examining a group of neurons in the brain that show alterations in neural activity when flies are satiated or starved. PMID:27505238

  3. Status of microbial control of house flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    House flies are major pests of human and animal health throughout the world and are among the most difficult to control because of resistance to every insecticide that has been developed for their control. There are a variety of microbial agents available to manage flies, each with advantages and d...

  4. A NASA study of the impact of technology on future sea based attack aircraft

    NASA Technical Reports Server (NTRS)

    Hahn, Andrew S.

    1992-01-01

    A conceptual aircraft design study was recently completed evaluating carrier-based, subsonic attack aircraft using contemporary and future technology assumptions. The study examined a configuration matrix that was made up of light and medium bomb loads, one and two man crews, internal and external weapons carriage, as well as conventional and flying wing planforms. Use of common technology assumptions, engine cycle simulation code, design mission, and consistent application of methods allow for direct comparison of the aircraft. This paper describes the design study ground rules and the aircraft designed. The aircraft descriptions include weights, dimensions, layout, design mission, design constraints, maneuver performance, and fallout mission performance. The strengths, and weaknesses of each aircraft are highlighted.

  5. Temperature Effects on Olive Fruit Fly Infestation in the FlySim Cellular Automata Model

    NASA Astrophysics Data System (ADS)

    Bruno, Vincenzo; Baldacchini, Valerio; di Gregorio, Salvatore

    FlySim is a Cellular Automata model developed for simulating infestation of olive fruit flies (Bactrocera Oleae) on olive (Olea europaea) groves. The flies move into the groves looking for mature olives where eggs are spawn. This serious agricultural problem is mainly tackled by using chemical agents at the first signs of the infestation, but organic productions with no or few chemicals are strongly requested by the market. Oil made with infested olives is poor in quality, nor olives are suitable for selling in stores. The FlySim model simulates the diffusion of flies looking for mature olives and the growing of flies due to atmospheric conditions. Foreseeing an infestation is the best way to prevent it and to reduce the need of chemicals in agriculture. In this work we investigated the effects of temperature on olive fruit flies and resulting infestation during late spring and summer.

  6. Efficient Certificate-Based Signcryption Secure against Public Key Replacement Attacks and Insider Attacks

    PubMed Central

    Li, Jiguo

    2014-01-01

    Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certificate-based signcryption scheme is insecure in our model. We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks. We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable. Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature. PMID:24959606

  7. Construction procedures using self hardening fly ash

    NASA Astrophysics Data System (ADS)

    Thornton, S. I.; Parker, D. G.

    1980-07-01

    Fly ash produced in Arkansas from burning Wyoming low sulfur coal is self-hardening and can be effective as a soil stabilizing agent for clays and sands. The strength of soil-self hardening fly ash develops rapidly when compacted immediately after mixing. Seven day unconfined compressive strengths up to 1800 psi were obtained from 20% fly ash and 80% sand mixtures. A time delay between mixing the fly ash with the soil and compaction of the mixture reduced the strength. With two hours delay, over a third of the strength was lost and with four hours delay, the loss was over half. Gypsum and some commercial concrete retarders were effective in reducing the detrimental effect of delayed compaction. Adequate mixing of the soil and fly ash and rapid compaction of the mixtures were found to be important parameters in field construction of stabilized bases.

  8. Adsorption of phenolic compounds on fly ash

    SciTech Connect

    Akgerman, A.; Zardkoohi, M.

    1996-03-01

    Adsorption isotherms for adsorption of phenol, 3-chlorophenol, and 2,4-dichlorophenol from water onto fly ash were determined. These isotherms were modeled by the Freundlich isotherm. The fly ash adsorbed 67, 20, and 22 mg/g for phenol, chlorophenol, and 2,4-dichlorophenol, respectively, for the highest water phase concentrations used. The affinity of phenolic compounds for fly ash is above the expected amount corresponding to a monolayer coverage considering that the surface area of fly ash is only 1.87 m{sup 2}/g. The isotherms for contaminants studied were unfavorable, indicating that adsorption becomes progressively easier as more solutes are taken up. Phenol displayed a much higher affinity for fly ash than 3-chlorophenol and 2,4-dichlorophenol.

  9. ACAA fly ash basics: quick reference card

    SciTech Connect

    2006-07-01

    Fly ash is a fine powdery material created when coal is burned to generate electricity. Before escaping into the environment via the utility stacks, the ash is collected and may be stored for beneficial uses or disposed of, if necessary. The use of fly ash provides environmental benefits, such as the conservation of natural resources, the reduction of greenhouse gas emissions and eliminating the needed for ash disposal in landfills. It is also a valuable mineral resource that is used in construction and manufacturing. Fly ash is used in the production of Portland cement, concrete, mortars and stuccos, manufactured aggregates along with various agricultural applications. As mineral filler, fly ash can be used for paints, shingles, carpet backing, plastics, metal castings and other purposes. This quick reference card is intended to provide the reader basic source, identification and composition, information specifically related to fly ash.

  10. Flightless Flies: Drosophila models of neuromuscular disease

    PubMed Central

    Lloyd, Thomas E.; Taylor, J. Paul

    2010-01-01

    The fruit fly, Drosophila melanogaster, has a long and rich history as an important model organism for biologists. In particular, study of the fruit fly has been essential to much of our fundamental understanding of the development and function of the nervous system. In recent years, studies using fruit flies have provided important insights into the pathogenesis of neurodegenerative and neuromuscular diseases. Fly models of spinal muscular atrophy, spinobulbar muscular atrophy, myotonic dystrophy, dystrophinopathies and other inherited neuromuscular diseases recapitulate many of the key pathologic features of the human disease. The ability to perform genetic screens holds promise for uncovering the molecular mechanisms of disease, and indeed, for identifying novel therapeutic targets. This review will summarize recent progress in developing fly models of neuromuscular diseases and will emphasize the contribution that Drosophila has made to our understanding of these diseases. PMID:20329357

  11. Web Forms and Untraceable DDoS Attacks

    NASA Astrophysics Data System (ADS)

    Jakobsson, Markus; Menczer, Filippo

    We analyze a Web vulnerability that allows an attacker to perform an email-based attack on selected victims, using standard scripts and agents. What differentiates the attack we describe from other, already known forms of distributed denial of service (DDoS) attacks is that an attacker does not need to infiltrate the network in any manner - as is normally required to launch a DDoS attack. Thus, we see this type of attack as a poor man's DDoS. Not only is the attack easy to mount, but it is also almost impossible to trace back to the perpetrator. Along with descriptions of our attack, we demonstrate its destructive potential with (limited and contained) experimental results. We illustrate the potential impact of our attack by describing how an attacker can disable an email account by flooding its inbox; block competition during on-line auctions; harm competitors with an on-line presence; disrupt phone service to a given victim; disconnect mobile corporate leaders from their networks; and disrupt electronic elections. Finally, we propose a set of countermeasures that are light-weight, do not require modifications to the infrastructure, and can be deployed in a gradual manner.

  12. Machine Learning Methods for Attack Detection in the Smart Grid.

    PubMed

    Ozay, Mete; Esnaola, Inaki; Yarman Vural, Fatos Tunay; Kulkarni, Sanjeev R; Poor, H Vincent

    2016-08-01

    Attack detection problems in the smart grid are posed as statistical learning problems for different attack scenarios in which the measurements are observed in batch or online settings. In this approach, machine learning algorithms are used to classify measurements as being either secure or attacked. An attack detection framework is provided to exploit any available prior knowledge about the system and surmount constraints arising from the sparse structure of the problem in the proposed approach. Well-known batch and online learning algorithms (supervised and semisupervised) are employed with decision- and feature-level fusion to model the attack detection problem. The relationships between statistical and geometric properties of attack vectors employed in the attack scenarios and learning algorithms are analyzed to detect unobservable attacks using statistical learning methods. The proposed algorithms are examined on various IEEE test systems. Experimental analyses show that machine learning algorithms can detect attacks with performances higher than attack detection algorithms that employ state vector estimation methods in the proposed attack detection framework. PMID:25807571

  13. Detection of hydrogen attack in base metal and weld HAZ

    SciTech Connect

    Birring, A.S.; Elliot, J.; Hsiao, C.P.

    1995-12-01

    Hydrogen attack is known to occur in C-1/2Mo steels operating at high temperature and pressure in the hydrogen environment. The attack occurs in the base metal as well as in the weld heat affected zone (HAZ) of vessels and pipes. Hydrogen attack reduces the strength and toughness of steel and, if left undetected, can lead to component failure. Failures can be avoided by timely application of reliable and sensitive nondestructive techniques. Ultrasonic techniques were developed and applied to detect hydrogen attack in both the base metal and weld HAZ attack. Ultrasonic backscatter and velocity ratio techniques were applied for detection of base metal attack. These techniques are, however, not suitable for detection of HAZ attack. Conventional shear wave examination is currently used for HAZ inspection. This method can detect large cracks but is not sensitive to detect microcracks produced by hydrogen attack. A combination of two techniques was developed for detection of HAZ attack. These techniques are: contact focused angle beam S-wave and pitch-catch L-wave. The first technique focuses the beam using an acoustic lens while the second technique uses the intersection point of the two pitch-catch beam axes to illuminate the HAZ zone. Both the focused and pitch-catch techniques were applied on samples with simulated HAZ attack. The techniques were successful in detecting simulated attack.

  14. LAN attack detection using Discrete Event Systems.

    PubMed

    Hubballi, Neminath; Biswas, Santosh; Roopa, S; Ratti, Ritesh; Nandi, Sukumar

    2011-01-01

    Address Resolution Protocol (ARP) is used for determining the link layer or Medium Access Control (MAC) address of a network host, given its Internet Layer (IP) or Network Layer address. ARP is a stateless protocol and any IP-MAC pairing sent by a host is accepted without verification. This weakness in the ARP may be exploited by malicious hosts in a Local Area Network (LAN) by spoofing IP-MAC pairs. Several schemes have been proposed in the literature to circumvent these attacks; however, these techniques either make IP-MAC pairing static, modify the existing ARP, patch operating systems of all the hosts etc. In this paper we propose a Discrete Event System (DES) approach for Intrusion Detection System (IDS) for LAN specific attacks which do not require any extra constraint like static IP-MAC, changing the ARP etc. A DES model is built for the LAN under both a normal and compromised (i.e., spoofed request/response) situation based on the sequences of ARP related packets. Sequences of ARP events in normal and spoofed scenarios are similar thereby rendering the same DES models for both the cases. To create different ARP events under normal and spoofed conditions the proposed technique uses active ARP probing. However, this probing adds extra ARP traffic in the LAN. Following that a DES detector is built to determine from observed ARP related events, whether the LAN is operating under a normal or compromised situation. The scheme also minimizes extra ARP traffic by probing the source IP-MAC pair of only those ARP packets which are yet to be determined as genuine/spoofed by the detector. Also, spoofed IP-MAC pairs determined by the detector are stored in tables to detect other LAN attacks triggered by spoofing namely, man-in-the-middle (MiTM), denial of service etc. The scheme is successfully validated in a test bed. PMID:20804980

  15. Explosive attack: Lessons learned in Seyed Al Shohada mosque attack, April 2008, Shiraz, Iran

    PubMed Central

    Paydar, Shahram; Sharifian, Maryam; Parvaz, Shahram Boland; Abbasi, Hamid Reza; Moradian, Mohamad javad; Roozbeh, Jamshid; Nikghbalian, Saman; Sagheb, Mohammad Mahdi; Ghaffarpasand, Fariborz; Salehi, Oveis; Dehghani, Javad

    2012-01-01

    Introduction: The threat of explosive attacks has become a worldwide problem. Bombing is the preferred method of attacks. These attacks result in specific physical and psychiatric trauma. In this paper, we present an epidemiologic description of the physical injuries of patients who survived the explosive attack in Seyed Al Shohada mosque April 2008 Shiraz, Iran. Materials and Methods: All medical records of the patients admitted at Shiraz Hospitals on April 2008 due to Seyed Al Shohada mosque bombing attacks, Shiraz, Iran, were reviewed. Results: A total of 202 patients were referred to the hospitals over 24 h following the terrorist attack. One hundred sixty-four patients were admitted for short periods of observation (<24 h). Thirty-eight patients needed more than 1 day of hospitalization. The mean age of the patients was 26.2 (range 2 to 51) years. One hundred thirty-five (66.8%) patients were males. Twenty-six (12.8%) were children. Burn was the most prevalent cause of admission. Five (13.5%) patients needed chest tube insertion and eight (21%) needed skin grafts due to burn. Overall, 12 patients expired (5%). Three (25%) of them were children (2 and 6, and 11 years old). Mortality rate was significantly higher among the children than adults (P value <0.05). The most important cause of death was head trauma which was seen in five (41.6%) of the expired patients followed by burn (including air way burn) in four (33%), and internal bleeding in three (25%). Patients with head trauma had significantly a higher rate of mortality than other patients (P value <0.05). Discussion: Following a bombing attack, numerous victims were brought to the emergency unit suffering from a combination of multi-organ injuries caused by the blast, penetrating injuries caused by shrapnel and other debris, and burns. It is important for a physician to be familiar with the clinical features and treatments of explosive attacks victims. Early management of patients at the scene and

  16. Bobcat attack on a cottontail rabbit

    USGS Publications Warehouse

    Biggins, D.E.; Biggins, D.M.

    2006-01-01

    We observed an attack by a bobcat (Lynx rufus) on a cottontail rabbit (Sylvilagus) that involved stealthy approach by the cat for >1 h, followed by a 12.3-s chase covering 116.0 m for the cat and 128.4 m for the rabbit. During the chase, the route of the cat from starting point to kill site was more direct than the semi-circular route of the rabbit. Stride lengths for the cat and total distance covered by the chase were longer than those previously reported for bobcats.

  17. X-29 high angle of attack

    NASA Technical Reports Server (NTRS)

    Ishmael, Stephen D.; Smith, Rogers E.; Purifoy, Dana D.; Womer, Rodney K.

    1990-01-01

    Flight test program highlights are discussed for the X-29 high angle-of-attack (AOA) aircraft. The AOA envelope extended from 10 to 66 deg; the X-29 exhibited precise pitch control, allowing AOA to be maintained within 1 deg during stabilized points as well as permitting rapid recoveries from all AOAs. Attention is given to controllability degradation above 40-deg AOA due to asymmetric yawing moments. The use of this aircraft as a fundamental research tool which complements analytical methods is powerfully justified by the obviation of scaling effects.

  18. Indicators of acute pain and fly avoidance behaviors in Holstein calves following tail-docking.

    PubMed

    Eicher, S D; Dalley, J W

    2002-11-01

    Previous work showed that the banding process of docking minimally affected mature cows' behavior and physiology, but cutting off the necrotic tail increased haptoglobin. Additionally the docked cows had more flies on the rear legs and exhibited more fly avoidance behaviors. Because many producers dock young calves while they are in hutches where fly problems are more pronounced, we investigated changes in behavior and physiology of young calves following docking by banding. Twenty calves (3 to 5 wk of age) were assigned to a docked or control group, at each of two locations (Indiana and Wisconsin). After applying a band to dock the tail, calves were tested every 15 min for sensitivity to heat below the band at the Indiana location. Calf behavior was recorded for 2 h postbanding and analyzed continuously for that period. After 3 wk, tails were removed and then 1 wk later, fly counts and fly avoidance behaviors were observed at both locations. Tails were sensitive to heat below the banding site, for 60 to 120 min postbanding (mean 87 min). Banded calves were more active than control calves during the 2 h following banding. Percentage of time spent lying was greater for control calves, and the percentage of time spent walking was greater for docked than control calves. More importantly, movements of the head to touch the tail were increased for banded calves (eight-fold more movements). Fly avoidance behaviors directed toward the rear of the calf were evident at noon or in the afternoon. Ear twitches were more frequent for the docked calves and less frequent in the morning for all calves. Licking was more frequent for the docked calves at 1200 and 1600 h. Tail swings were most frequent at 1200 and more frequent for control calves. Two acute phase proteins, haptoglobin and alpha1 acid-glycoprotein, were not different at any time. In this study, calves that were banded at 3-wk-of-age showed behaviors indicative of discomfort for 2 h, were attacked by more flies, and

  19. Fly Photoreceptors Encode Phase Congruency

    PubMed Central

    Friederich, Uwe; Billings, Stephen A.; Hardie, Roger C.; Juusola, Mikko; Coca, Daniel

    2016-01-01

    More than five decades ago it was postulated that sensory neurons detect and selectively enhance behaviourally relevant features of natural signals. Although we now know that sensory neurons are tuned to efficiently encode natural stimuli, until now it was not clear what statistical features of the stimuli they encode and how. Here we reverse-engineer the neural code of Drosophila photoreceptors and show for the first time that photoreceptors exploit nonlinear dynamics to selectively enhance and encode phase-related features of temporal stimuli, such as local phase congruency, which are invariant to changes in illumination and contrast. We demonstrate that to mitigate for the inherent sensitivity to noise of the local phase congruency measure, the nonlinear coding mechanisms of the fly photoreceptors are tuned to suppress random phase signals, which explains why photoreceptor responses to naturalistic stimuli are significantly different from their responses to white noise stimuli. PMID:27336733

  20. Fly Photoreceptors Encode Phase Congruency.

    PubMed

    Friederich, Uwe; Billings, Stephen A; Hardie, Roger C; Juusola, Mikko; Coca, Daniel

    2016-01-01

    More than five decades ago it was postulated that sensory neurons detect and selectively enhance behaviourally relevant features of natural signals. Although we now know that sensory neurons are tuned to efficiently encode natural stimuli, until now it was not clear what statistical features of the stimuli they encode and how. Here we reverse-engineer the neural code of Drosophila photoreceptors and show for the first time that photoreceptors exploit nonlinear dynamics to selectively enhance and encode phase-related features of temporal stimuli, such as local phase congruency, which are invariant to changes in illumination and contrast. We demonstrate that to mitigate for the inherent sensitivity to noise of the local phase congruency measure, the nonlinear coding mechanisms of the fly photoreceptors are tuned to suppress random phase signals, which explains why photoreceptor responses to naturalistic stimuli are significantly different from their responses to white noise stimuli. PMID:27336733

  1. Fruit flies in biomedical research.

    PubMed

    Wangler, Michael F; Yamamoto, Shinya; Bellen, Hugo J

    2015-03-01

    Many scientists complain that the current funding situation is dire. Indeed, there has been an overall decline in support in funding for research from the National Institutes of Health and the National Science Foundation. Within the Drosophila field, some of us question how long this funding crunch will last as it demotivates principal investigators and perhaps more importantly affects the long-term career choice of many young scientists. Yet numerous very interesting biological processes and avenues remain to be investigated in Drosophila, and probing questions can be answered fast and efficiently in flies to reveal new biological phenomena. Moreover, Drosophila is an excellent model organism for studies that have translational impact for genetic disease and for other medical implications such as vector-borne illnesses. We would like to promote a better collaboration between Drosophila geneticists/biologists and human geneticists/bioinformaticians/clinicians, as it would benefit both fields and significantly impact the research on human diseases. PMID:25624315

  2. Fruit Flies in Biomedical Research

    PubMed Central

    Wangler, Michael F.; Yamamoto, Shinya; Bellen, Hugo J.

    2015-01-01

    Many scientists complain that the current funding situation is dire. Indeed, there has been an overall decline in support in funding for research from the National Institutes of Health and the National Science Foundation. Within the Drosophila field, some of us question how long this funding crunch will last as it demotivates principal investigators and perhaps more importantly affects the long-term career choice of many young scientists. Yet numerous very interesting biological processes and avenues remain to be investigated in Drosophila, and probing questions can be answered fast and efficiently in flies to reveal new biological phenomena. Moreover, Drosophila is an excellent model organism for studies that have translational impact for genetic disease and for other medical implications such as vector-borne illnesses. We would like to promote a better collaboration between Drosophila geneticists/biologists and human geneticists/bioinformaticians/clinicians, as it would benefit both fields and significantly impact the research on human diseases. PMID:25624315

  3. Treatment of fly ash for use in concrete

    DOEpatents

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  4. Treatment of fly ash for use in concrete

    DOEpatents

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  5. Treatment of fly ash for use in concrete

    DOEpatents

    Boxley, Chett

    2012-05-15

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  6. Baiting Inside Attackers Using Decoy Documents

    NASA Astrophysics Data System (ADS)

    Bowen, Brian M.; Hershkop, Shlomo; Keromytis, Angelos D.; Stolfo, Salvatore J.

    The insider threat remains one of the most vexing problems in computer security. A number of approaches have been proposed to detect nefarious insider actions including user modeling and profiling techniques, policy and access enforcement techniques, and misuse detection. In this work we propose trap-based defense mechanisms and a deployment platform for addressing the problem of insiders attempting to exfiltrate and use sensitive information. The goal is to confuse and confound an adversary requiring more effort to identify real information from bogus information and provide a means of detecting when an attempt to exploit sensitive information has occurred. “Decoy Documents” are automatically generated and stored on a file system by the D3 System with the aim of enticing a malicious user. We introduce and formalize a number of properties of decoys as a guide to design trap-based defenses to increase the likelihood of detecting an insider attack. The decoy documents contain several different types of bogus credentials that when used, trigger an alert. We also embed “stealthy beacons” inside the documents that cause a signal to be emitted to a server indicating when and where the particular decoy was opened. We evaluate decoy documents on honeypots penetrated by attackers demonstrating the feasibility of the method.

  7. Spontaneous subperiosteal hematoma precipitated by anxiety attack.

    PubMed

    Swanenberg, Irene M; Rizzuti, Allison E; Shinder, Roman

    2013-12-01

    A 60-year-old woman presented with diplopia and left periorbital edema and pressure, which developed during an anxiety attack the previous day. Examination revealed left inferotemporal globe dystopia, periorbital edema, ecchymosis, and limitation in supraduction. Orbital MRI confirmed the diagnosis of a superior subperiosteal orbital hematoma. The patient's signs and symptoms rapidly resolved with administration of oral corticosteroids. The patient remains asymptomatic with complete resolution of orbital signs at 3-month follow-up. Subperiosteal orbital hematoma (SOH) is a rare condition in which blood accumulates between the bony orbit and separated periosteum, and is often due to blunt head trauma. Non-traumatic SOH (NTSOH) is exceedingly rare and usually associated with known coagulopathies or tendency to bleed. However, few cases of spontaneous NTSOH have been reported without any such predisposition and are thought to be caused by sudden elevations in intrathoracic and intracranial venous pressure such as vomiting, coughing, SCUBA diving, weight lifting and labor. We herein describe the presentation, radiography and outcome of a unique case of spontaneous NTSOH following an anxiety attack. PMID:24063522

  8. Flying fruit flies correct for visual sideslip depending on relative speed of forward optic flow

    PubMed Central

    Cabrera, Stephanie; Theobald, Jamie C.

    2013-01-01

    As a fly flies through its environment, static objects produce moving images on its retina, and this optic flow is essential for steering and course corrections. Different types of rotation and translation produce unique flow fields, which fly brains are wired to identify. However, a feature of optic flow unique to translational motion is that adjacent images may move across the retina at different speeds, depending on their distance from the observer. Many insects take advantage of this depth cue, called motion parallax, to determine the distance to objects. We wanted to know if differential object speeds affect the corrective responses of fruit flies when they experience unplanned course deviations. We presented tethered flying flies with optic flow and measured their corrective responses to sideways perturbations of images with different relative forward speeds. We found that flying flies attend to the relative speed of dots during forward motion, and adjust their corrective responses to sideslip deviations depending on this cue. With no other distinguishing features (such as brightness or size), flies mounted a greater response to sideways deviations that were signaled by faster moving dots in the forward flow field, those that appeared radially closer by their speeds. This is consistent with the interpretation that fruit flies attend to seemingly nearer objects, and correct more strongly when they indicate a perturbation. PMID:23847482

  9. Use of the Panic Attack Questionnaire-IV to assess non-clinical panic attacks and limited symptom panic attacks in student and community samples.

    PubMed

    Norton, Peter J; Zvolensky, Michael J; Bonn-Miller, Marcel O; Cox, Brian J; Norton, G Ron

    2008-10-01

    Since its development in the mid-1980s, the Panic Attack Questionnaire (PAQ) has been one of the more, if not the most, commonly used self-report tools for assessing panic attacks. The usage of the instrument, however, has come amid potential concerns that instructions and descriptions may lead to an over-estimate of the prevalence of panic attacks. Furthermore, the instrument has not been revised since 1992, despite changes in DSM-IV criteria and more recent developments in the understanding of panic attacks. As a result, this paper describes a revision of the PAQ to improve the instruction and descriptive set, and to fully assess features of panic derived from recent conceptualizations. Students meeting DSM-IV panic attack criteria and those endorsing panic attacks, but not meeting criteria, showed few differences with the exception that those not meeting DSM-IV criteria typically reported a longer onset-to-peak intensity time than did Panickers. Results were cross-validated and extended using an independent Community Sample. A full descriptive phenomenology of panic attacks is described, and future directions for studying panic attacks using the PAQ are presented. PMID:18243647

  10. Kohonen's feature maps for fly ash categorization.

    PubMed

    Nataraja, M C; Jayaram, M A; Ravikumar, C N

    2006-12-01

    Fly ash is a common admixture used in concrete and may constitute up to 50% by weight of the total binder material. Incorporation of fly ash in Portland-cement concrete is highly desirable due to technological, economic, and environmental benefits. This article demonstrates the use of artificial intelligence neural networks for the classification of fly ashes in to different groups. Kohonen's Self Organizing Feature Maps is used for the purpose. As chemical composition of fly ash is crucial in the performance of concrete, eight chemical attributes of fly ashes have been considered. The application of simple Kohonen's one-dimensional feature maps permitted to differentiate three main groups of fly ashes. Three one-dimensional feature maps of topology 8-16, 8-24 and 8-32 were explored. The overall classification result of 8-16 topology was found to be significant and encouraging. The data pertaining to 80 fly ash samples were collected from standard published works. The categorization was found to be excellent and compares well with Canadian Standard Association's [CSA A 3000] classification scheme. PMID:17285691

  11. Erodibility of fly ash-treated minesoils

    SciTech Connect

    Gorman, J.M.; Sencindiver, J.C.; Singh, R.N.

    1997-12-31

    Fly ash, a by-product of coal-fired power plants, has been used successfully in reclaiming adverse mine sites such as abandoned mine lands by improving minesoil chemical and physical properties. But, the fine sand-silt particle size of fly ash may make it more susceptible to detachment and transport by erosive processes. Furthermore, the high content of silt-size particles in fly ash may make it more susceptable to surface crust formation resulting in reduced infiltration and increased surface runoff and erosion. In the summer of 1989, fly ash/wood waste mixtures were surface applied on two separate mine sites, one with 10% slope and the other 20% slope, in central Preston County, West Virginia. Erosion rates were measured directly using the Linear Erosion/Elevation Measuring Instrument (LEMI). Erosion measurements were taken during the first two growing seasons on both sites. Erosion values were up to five times greater on the fly ash-treated minesoil than on the minesoil without fly ash cover. Mulching with wood chips reduced fly ash erosion to about one-half the loss of the unmulched plots. Erosion was related to both the amount and type of ground cover. Increased vegetative ground cover resulted in reduced erosion. Mosses and fungi appeared to provide better erosion protection than grass-legume cover.

  12. Causal Attribution, Perceived Benefits, and Morbidity After a Heart Attack: An 8-Year Study.

    ERIC Educational Resources Information Center

    Affleck, Glenn; And Others

    1987-01-01

    Interviewed heart attack victims (N=287) seven weeks and eight years after their attack. Explored interrelations among causal attributions for the attack, survivor morbidity, and heart attack recurrence. Found that patients who cited benefits from their misfortune seven weeks after the first attack were less likely to have another attack and had…

  13. Knuckleball and Flying Disk: Boundary Layer Transitions, Separations and Vortex Wakes in Sports Aerodynamics

    NASA Astrophysics Data System (ADS)

    Higuchi, Hiroshi; Kiura, Toshiro; Goto, Yuichiro; Hiramoto, Riho

    2001-11-01

    In spite of their popularity, flow structures over common baseball and flying disks have not been studied in detail. A slowly rotating baseball is subject to erratic flight paths, and is known as a knuckleball. In the present experiment, the characteristic of force acting on a baseball was obtained and the velocity vector field near the surface of the ball and the wake were measured with the DPIV technique. The seam triggered the boundary layer transition or caused the boundary layer separation itself. The laminar/turbulent boundary layer separations were identified with specific ball orientations. Corresponding three-dimensional wake pattern and the side force result in unpredictable trajectories. In the second part of the talk, flow physics regarding a spin-stabilized flying disk is addressed. The roll-up of trailing vortices was visualized in detail and their vorticity field was measured with the DPIV. The vortical flow over the disk produced flow reattachment at a very high angle of attack. The boundary layer at low angles of attack was affected by the surface motion with asymmetric boundary layer transitions as evidenced by the flow visualization and the hot wire survey. The flow separation and attachment on the underside cavity were also affected by the rotation.

  14. An Overview of Controls and Flying Qualities Technology on the F/A-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Pahle, Joseph W.; Wichman, Keith D.; Foster, John V.; Bundick, W. Thomas

    1996-01-01

    The NASA F/A-18 High Alpha Research Vehicle (HARV) has been the flight test bed of a focused technology effort to significantly increase maneuvering capability at high angles of attack. Development and flight test of control law design methodologies, handling qualities metrics, performance guidelines, and flight evaluation maneuvers are described. The HARV has been modified to include two research control effectors, thrust vectoring, and actuated forebody strakes in order to provide increased control power at high angles of attack. A research flight control system has been used to provide a flexible, easily modified capability for high-angle-of-attack research controls. Different control law design techniques have been implemented and flight-tested, including eigenstructure assignment, variable gain output feedback, pseudo controls, and model-following. Extensive piloted simulation has been used to develop nonlinear performance guide-lines and handling qualities criteria for high angles of attack. This paper reviews the development and evaluation of technologies useful for high-angle-of-attack control. Design, development, and flight test of the research flight control system, control laws, flying qualities specifications, and flight test maneuvers are described. Flight test results are used to illustrate some of the lessons learned during flight test and handling qualities evaluations.

  15. Effects of fly ash particle size on strength of Portland cement fly ash mortars

    SciTech Connect

    Erdogdu, K.; Tuerker, P.

    1998-09-01

    Fly ashes do not have the same properties for different size fractions. It can be accepted that the effect of a fly ash on mortar strength is a combined effect of its size fractions. Therefore, it was concluded that by separating the size fractions and replacing cement with them, the combined bulk effect of a fly ash on strength can be better analyzed. In this study, different size fractions of fly ash were used to replace cement partially in standard compressive strength mortars. The authors attempted to interpret the strength of Portland cement-fly ash mortars in terms of the chemical, mineralogical, morphological, and physical properties of different fly ash size fractions used. Strengths of the mortars were compared at 2, 7, 28, and 90 days. Also strength of mortars with all-in ash (original ash containing all the fractions) were estimated by using strength of mortars with size fractions and the suitability of this estimation was discussed.

  16. Managing burn victims of suicide bombing attacks: outcomes, lessons learnt, and changes made from three attacks in Indonesia

    PubMed Central

    Chim, Harvey; Yew, Woon Si; Song, Colin

    2007-01-01

    Introduction Terror attacks in Southeast Asia were almost nonexistent until the 2002 Bali bomb blast, considered the deadliest attack in Indonesian history. Further attacks in 2003 (Jakarta), 2004 (Jakarta), and 2005 (Bali) have turned terrorist attacks into an ever-present reality. Methods The authors reviewed medical charts of victims evacuated to the Singapore General Hospital (SGH) Burns Centre during three suicide attacks involving Bali (2002 and 2005) and the Jakarta Marriott hotel (2003). Problems faced, lessons learnt, and costs incurred are discussed. A burns disaster plan drawing on lessons learnt from these attacks is presented. Results Thirty-one patients were treated at the SGH Burns Centre in three attacks (2002 Bali attack [n = 15], 2003 Jakarta attack [n = 14], and 2005 Bali attack [n = 2]). For the 2002 Bali attack, median age was 29 years (range 20 to 50 years), median percentage of total burn surface area (TBSA) was 29% (range 5% to 55%), and median abbreviated burn severity index (ABSI) was 6 (range 3 to 10). Eight of 15 patients were admitted to the intensive care unit. For the 2003 Jakarta attack, median age was 35 years (range 24 to 56 years), median percentage of TBSA was 10% (range 2% to 46%), and median ABSI was 4 (range 3 to 9). A large number of patients had other injuries. Problems faced included manpower issues, lack of bed space, shortage of blood products, and lack of cadaver skin. Conclusion The changing nature of terror attacks mandates continued vigilance and disaster preparedness. The multidimensional burns patient, complicated by other injuries, is likely to become increasingly common. A burns disaster plan with emphasis on effective command, control, and communication as well as organisation of health care personnel following a 'team concept' will do much to ensure that the sudden onset of a crisis situation at an unexpected time does not overwhelm hospital manpower and resources. PMID:17274813

  17. 32 CFR 855.13 - Civil fly-ins.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Civil fly-ins. 855.13 Section 855.13 National... UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits § 855.13 Civil fly-ins. (a) Civil... or provide a static display. (2) A flying safety seminar. (b) Civil fly-in procedures: (1)...

  18. 32 CFR 855.13 - Civil fly-ins.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Civil fly-ins. 855.13 Section 855.13 National... UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits § 855.13 Civil fly-ins. (a) Civil... or provide a static display. (2) A flying safety seminar. (b) Civil fly-in procedures: (1)...

  19. Non-harmful insertion of data mimicking computer network attacks

    DOEpatents

    Neil, Joshua Charles; Kent, Alexander; Hash, Jr, Curtis Lee

    2016-06-21

    Non-harmful data mimicking computer network attacks may be inserted in a computer network. Anomalous real network connections may be generated between a plurality of computing systems in the network. Data mimicking an attack may also be generated. The generated data may be transmitted between the plurality of computing systems using the real network connections and measured to determine whether an attack is detected.

  20. Attack polish for nickel-base alloys and stainless steels

    DOEpatents

    Steeves, Arthur F.; Buono, Donald P.

    1983-01-01

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels. The chemical attack polish comprises Fe(NO.sub.3).sub.3, concentrated CH.sub.3 COOH, concentrated H.sub.2 SO.sub.4 and H.sub.2 O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  1. Attack polish for nickel-base alloys and stainless steels

    DOEpatents

    Not Available

    1980-05-28

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels is described. The chemical attack polich comprises FeNO/sub 3/, concentrated CH/sub 3/COOH, concentrated H/sub 2/SO/sub 4/ and H/sub 2/O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  2. On the offensive against brain attack

    SciTech Connect

    Wheatcraft, D.

    1997-06-01

    The Center for Healthcare Technologies at Lawrence Livermore National Laboratory has undertaken a stroke initiative whose purpose is to provide the medical community with the tools that will allow doctors to diagnose and treat stroke as aggressively as they do heart attack. A multidisciplinary team of stroke-initiative researchers is collaborating with academic medical centers and private companies to move these tools from the research and development stage through clinical trials, regulatory approval, and manufacture so that they can benefit many thousands of people who have strokes each year. Tools the team has developed fall into four categories: microsensors for brain and clot characterization, a catheter-based system using laser energy to break up clots in the blood vessels of the brain, laser-tissue interaction models in support of laser {open_quotes}clot busting,{close_quotes} and microtools for treating the aneurysms that cause hemorrhagic stroke.

  3. Attacks on lexical natural language steganography systems

    NASA Astrophysics Data System (ADS)

    Taskiran, Cuneyt M.; Topkara, Umut; Topkara, Mercan; Delp, Edward J.

    2006-02-01

    Text data forms the largest bulk of digital data that people encounter and exchange daily. For this reason the potential usage of text data as a covert channel for secret communication is an imminent concern. Even though information hiding into natural language text has started to attract great interest, there has been no study on attacks against these applications. In this paper we examine the robustness of lexical steganography systems.In this paper we used a universal steganalysis method based on language models and support vector machines to differentiate sentences modified by a lexical steganography algorithm from unmodified sentences. The experimental accuracy of our method on classification of steganographically modified sentences was 84.9%. On classification of isolated sentences we obtained a high recall rate whereas the precision was low.

  4. Capturing the uncertainty in adversary attack simulations.

    SciTech Connect

    Darby, John L.; Brooks, Traci N.; Berry, Robert Bruce

    2008-09-01

    This work provides a comprehensive uncertainty technique to evaluate uncertainty, resulting in a more realistic evaluation of PI, thereby requiring fewer resources to address scenarios and allowing resources to be used across more scenarios. For a given set of dversary resources, two types of uncertainty are associated with PI for a scenario: (1) aleatory (random) uncertainty for detection probabilities and time delays and (2) epistemic (state of knowledge) uncertainty for the adversary resources applied during an attack. Adversary esources consist of attributes (such as equipment and training) and knowledge about the security system; to date, most evaluations have assumed an adversary with very high resources, adding to the conservatism in the evaluation of PI. The aleatory uncertainty in PI is ddressed by assigning probability distributions to detection probabilities and time delays. A numerical sampling technique is used to evaluate PI, addressing the repeated variable dependence in the equation for PI.

  5. Resveratrol products resulting by free radical attack

    NASA Astrophysics Data System (ADS)

    Bader, Yvonne; Quint, R. M.; Getoff, Nikola

    2008-06-01

    Trans-resveratrol ( trans-3,4',5-trihydroxystilbene; RES), which is contained in red wine and many plants, is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. Among other duties, RES has been reported to have anti-carcinogenetic activities, which could be attributed to its antioxidant properties. The degradation of RES was studied under various conditions. The products (aldehydes, carboxylic acids, etc.) generated from RES by the attack of free radicals were registered as a function of the radical concentration (absorbed radiation dose). Based on the obtained data it appears that the OH radicals are initiating the rather complicated process, which involves of the numerous consecutive reactions. A possible starting reaction mechanism is presented.

  6. An optical angle of attack sensor

    NASA Astrophysics Data System (ADS)

    McDevitt, T. Kevin; Owen, F. Kevin

    A major source of transonic and supersonic wind-tunnel test data uncertainty is due to angle of attack (alpha) measurement errors caused by unknown sting and balance deflections under load. A novel laser-based instrument has been developed to enable continuous time-dependent alpha measurements to be made without signal dropout. Detectors capable of 0.01-deg resolution over an 18-deg range and 0.03-deg resolution over a 44-deg range with time-dependent outputs of 60 Hz have been developed. This capability is sufficient to provide accurate real-time alpha information for correlation with model balance measurements during transport and fighter model testing. Proof-of-concept experiments, along with the results of recent measurements conducted at the NASA Ames 9 x 7-ft supersonic wind tunnel, are presented. Experiments were also conducted to determine the reliable range, sensitivity, and long-term stability of the instrument.

  7. Mitigation of malicious attacks on network observation

    NASA Astrophysics Data System (ADS)

    Xiao, Yan-Dong; Lao, Song-Yang; Hou, Lv-Lin; Bai, Liang

    2015-02-01

    In the modeling, controlling, and monitoring of complex networks, a fundamental problem concerns the determination and observation of the system's states by using measurements or sensors as few as possible, defined as network observation. This work aims to investigate the robustness of network observation when an approach of minimum dominating set is considered in observing a network. We first investigate the structural properties of the minimum dominating sets, e.g. how the size depends on the degree-degree correlations and how to assess the nodes' importance in the malicious attacks. Then, we introduce a new measurement of robustness for network observation, and implement a hill-climbing algorithm to improve its robustness by edge rewiring. Furthermore, we propose a novel rewiring strategy, called smart rewiring, which could speed up the increment of robustness index. In comparison with previous strategy of edge rewiring, the smart rewiring has been found to be successfully useful on real-world and synthetic networks.

  8. Estimation of Static Longitudinal Stability of Aircraft Configurations at High Mach Numbers and at Angles of Attack Between 0 deg and +/-180 deg

    NASA Technical Reports Server (NTRS)

    Dugan, Duane W.

    1959-01-01

    The possibility of obtaining useful estimates of the static longitudinal stability of aircraft flying at high supersonic Mach numbers at angles of attack between 0 and +/-180 deg is explored. Existing theories, empirical formulas, and graphical procedures are employed to estimate the normal-force and pitching-moment characteristics of an example airplane configuration consisting of an ogive-cylinder body, trapezoidal wing, and cruciform trapezoidal tail. Existing wind-tunnel data for this configuration at a Mach number of 6.86 provide an evaluation of the estimates up to an angle of attack of 35 deg. Evaluation at higher angles of attack is afforded by data obtained from wind-tunnel tests made with the same configuration at angles of attack between 30 and 150 deg at five Mach numbers between 2.5 and 3.55. Over the ranges of Mach numbers and angles of attack investigated, predictions of normal force and center-of-pressure locations for the configuration considered agree well with those obtained experimentally, particularly at the higher Mach numbers.

  9. X-48B: How Does it Fly?

    NASA Video Gallery

    Gary Cosentino, lead flight operations engineer at NASA's Dryden Flight Research Center, talks about what it's like to fly the remotely piloted test vehicle -- X-48B -- a new kind of aircraft that ...

  10. Flying and danger, joy and fear.

    PubMed

    Jones, D R

    1986-02-01

    U.S. Air Force fliers are all volunteers who undergo rigorous training for their profession. Their motivation may be deeprooted and emotional, or may arise from a conscious decision made in early adulthood. Some motivation is flawed and fails early. Other motivation may be eroded by a single dangerous event, by an accumulation of "close calls" (one's own or others'), or by a growing interest in nonaviation elements. Since Air Force fliers may "quit" only at some personal cost to pride or pocketbook, they may develop a fear of flying. This may be truly phobic, a situational reaction, or an awareness of personal vulnerability. Some displace anxiety about flying into somatic symptoms. The author discusses motivation to fly, its various modes of failure, and some clinical aspects of fear of flying. PMID:3954701

  11. NASA Administrator Flies Dream Chaser Simulator

    NASA Video Gallery

    NASA Administrator Charlie Bolden had the opportunity to fly a simulated landing of the Sierra Nevada Corporation (SNC) Dream Chaser while touring the agency's Dryden Flight Research Center in Cali...

  12. Controlling roll perturbations in fruit flies.

    PubMed

    Beatus, Tsevi; Guckenheimer, John M; Cohen, Itai

    2015-04-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional-integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. PMID:25762650

  13. The chemical ecology of the fly.

    PubMed

    Mansourian, Suzan; Stensmyr, Marcus C

    2015-10-01

    Not only is the sense of smell of pivotal importance to most animals but also serves as a significant model system in biological research. In recent years, great strides in our understanding of how the olfactory system is organized and operates have been made. Instrumental in these efforts has been work performed in Drosophila melanogaster. In spite of the wealth of information gathered, it remains unclear how the fly's olfactory system is used to decode the chemical environment. Here we describe recent findings on the chemical ecology of the fly and speculate on possible functions of the volatile chemicals that flies detect. We argue that for many of the fly's olfactory chemoreceptors, distinct and ecologically relevant functions can be identified. PMID:25747730

  14. NASA Is With You When You Fly

    NASA Video Gallery

    Aviation touches us. Even if you didn't fly today, something you needed did. Did you know that NASA-developed technology is on board every U.S. commercial aircraft and in every U.S. control tower? ...

  15. Raindrops push and splash flying insects

    NASA Astrophysics Data System (ADS)

    Dickerson, Andrew K.; Shankles, Peter G.; Hu, David L.

    2014-02-01

    In their daily lives, flying insects face a gauntlet of environmental challenges, from wind gusts to raindrop impacts. In this combined experimental and theoretical study, we use high-speed videography to film raindrop collisions upon both flying insects and dynamically scaled spherical mimics. We identify three outcomes of the collision based upon the insect's mass and characteristic size: drops push the insect while remaining intact, coat the insect, and splash. We present a mathematical model that predicts impact force and outcome consistent with those found in experiments. Small insects such as gnats and flies are pushed by raindrops that remain intact upon impact; conversely, large flyers such as locusts and micro-aerial vehicles cause drops to splash. We identify a critical mass of 0.3 g for which flyers achieve both peak acceleration (100 g) and applied force (104 dyn) from incoming raindrops; designs of similarly massed flying robots should be avoided.

  16. Controlling roll perturbations in fruit flies

    PubMed Central

    Beatus, Tsevi; Guckenheimer, John M.; Cohen, Itai

    2015-01-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional–integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. PMID:25762650

  17. MMS Spacecraft Transition to Tetrahedral Flying Formation

    NASA Video Gallery

    In the latter half of July 2015, the four satellites of the Magnetosphere Multi-scale (MMS) mission move into their tetrahedral formation flying configuration as part of the checkout for the scienc...

  18. Leaching characteristics of lead from melting furnace fly ash generated by melting of incineration fly ash.

    PubMed

    Okada, Takashi; Tomikawa, Hiroki

    2012-11-15

    This study investigated the effect of the chemical composition of incineration fly ash on the leaching characteristics of Pb from melting furnace fly ash generated by melting incineration fly ash. Melting furnace fly ash from both a real-scale melting process and lab-scale melting experiments was analyzed. In addition, the theoretical behavior of Cl that affects the leaching characteristics of Pb was simulated by a thermodynamic equilibrium calculation. Proportions of water-soluble Pb in the melting furnace fly ash were correlated with equivalent ratios of total Pb in the ash and Cl transferred to gas. The amount of Cl in the gas increased with an increase in the molar ratio of Cl to Na and K in the incineration fly ash. The thermodynamic calculation predicted that HCl generation is promoted by the increase in the molar ratio, and X-ray photoelectron spectroscopy indicated a possible presence of PbCl(2) in the melting furnace fly ash. These results implied that the formation of water-soluble PbCl(2) with HCl was affected by the relationships among the amounts of Na, K, and Cl in the incineration fly ash. This is highly significant in determining the leaching characteristics of Pb from the melting furnace fly ash. PMID:22789656

  19. High-temperature corrosion of UNS N10003 in molten Li2BeF4 (FLiBe) salt

    DOE PAGESBeta

    Zheng, Guiqiu; Kelleher, Brian; He, Lingfeng; Cao, Guoping; Anderson, Mark; Allen, Todd; Sridharan, Kumar

    2015-07-30

    Here, corrosion testing of Hastelloy N in molten fluoride salt was performed in purified molten 27LiF-BeF2 (66-34mol%) (FLiBe) salt at 700°C for 1000 hours, in pure nickel and graphite capsules. In the nickel capsule tests, the near-surface region of the alloy exhibited an about 200 nm porous structure, an approximately 3.5 μm chromium depleted region, and MoSi2 precipitates. In tests performed in graphite capsules, the alloy samples gained weight due to the formation of a variety of Cr3C2, Cr7C3, Mo2C and Cr23C6, carbide phases on the surface and in the subsurface regions of the alloy. A Cr depleted region wasmore » observed in the near-surface region where Mo thermally diffused toward either surface or grain boundary, which induced approximately 1.4 μm Ni3Fe alloy layer in this region. The carbide containing layer extended to about 7 μm underneath the Ni3Fe layer. The presence of graphite dramatically changes the mechanisms of corrosion attack in Hastelloy N in molten FLiBe salt. Evaluated by in terms of the depth of attack, graphite clearly accelerates corrosion, but the results appear to indicate that the formation of Cr23C6 phase might stabilize the Cr and mitigate its dissolution in molten FLiBe salt.« less

  20. Techniques for Judging Intent Behind Network Based Cyber Attacks

    SciTech Connect

    Allen, J M

    2004-01-28

    This project developed a prototype system that can rapidly differentiate between undirected cyber attacks, and those that have a more specific and concerning intent behind them. The system responds to important cyber attacks in a tactically significant way as the attack is proceeding. It is also creates a prioritized list for the human analysts allowing them to focus on the threats mostly likely to be of interest. In the recent years the volume of attacks over the internet has increased exponentially, as they have become more and more automated. The result of this is that real threats are harder and harder to distinguish from the general threat. It is possible with our current systems to identify network packets that originated from thousands of IP addresses as probing a site like LLNL in a single day. Human analysis of these threats does not result in information that can be used for tactical response because most of the attacks are short and over before the human starts the analysis. Only a very small percentage of attacks can even be evaluated manually due to the volume. This project developed methods, and prototyped tools, that can identify attacks, slow the attack down and aid in the process of prioritizing detections. The project demonstrated that such methods exist, and that practical implementations exist for modern computers and networks. We call the tools created D.I.A.G. or Determining Internet Attackers Goals.

  1. Neural network classifier of attacks in IP telephony

    NASA Astrophysics Data System (ADS)

    Safarik, Jakub; Voznak, Miroslav; Mehic, Miralem; Partila, Pavol; Mikulec, Martin

    2014-05-01

    Various types of monitoring mechanism allow us to detect and monitor behavior of attackers in VoIP networks. Analysis of detected malicious traffic is crucial for further investigation and hardening the network. This analysis is typically based on statistical methods and the article brings a solution based on neural network. The proposed algorithm is used as a classifier of attacks in a distributed monitoring network of independent honeypot probes. Information about attacks on these honeypots is collected on a centralized server and then classified. This classification is based on different mechanisms. One of them is based on the multilayer perceptron neural network. The article describes inner structure of used neural network and also information about implementation of this network. The learning set for this neural network is based on real attack data collected from IP telephony honeypot called Dionaea. We prepare the learning set from real attack data after collecting, cleaning and aggregation of this information. After proper learning is the neural network capable to classify 6 types of most commonly used VoIP attacks. Using neural network classifier brings more accurate attack classification in a distributed system of honeypots. With this approach is possible to detect malicious behavior in a different part of networks, which are logically or geographically divided and use the information from one network to harden security in other networks. Centralized server for distributed set of nodes serves not only as a collector and classifier of attack data, but also as a mechanism for generating a precaution steps against attacks.

  2. Finite Energy and Bounded Attacks on Control System Sensor Signals

    SciTech Connect

    Djouadi, Seddik M; Melin, Alexander M; Ferragut, Erik M; Laska, Jason A

    2014-01-01

    Control system networks are increasingly being connected to enterprise level networks. These connections leave critical industrial controls systems vulnerable to cyber-attacks. Most of the effort in protecting these cyber-physical systems (CPS) has been in securing the networks using information security techniques and protection and reliability concerns at the control system level against random hardware and software failures. However, besides these failures the inability of information security techniques to protect against all intrusions means that the control system must be resilient to various signal attacks for which new analysis and detection methods need to be developed. In this paper, sensor signal attacks are analyzed for observer-based controlled systems. The threat surface for sensor signal attacks is subdivided into denial of service, finite energy, and bounded attacks. In particular, the error signals between states of attack free systems and systems subject to these attacks are quantified. Optimal sensor and actuator signal attacks for the finite and infinite horizon linear quadratic (LQ) control in terms of maximizing the corresponding cost functions are computed. The closed-loop system under optimal signal attacks are provided. Illustrative numerical examples are provided together with an application to a power network with distributed LQ controllers.

  3. Application distribution model and related security attacks in VANET

    NASA Astrophysics Data System (ADS)

    Nikaein, Navid; Kanti Datta, Soumya; Marecar, Irshad; Bonnet, Christian

    2013-03-01

    In this paper, we present a model for application distribution and related security attacks in dense vehicular ad hoc networks (VANET) and sparse VANET which forms a delay tolerant network (DTN). We study the vulnerabilities of VANET to evaluate the attack scenarios and introduce a new attacker`s model as an extension to the work done in [6]. Then a VANET model has been proposed that supports the application distribution through proxy app stores on top of mobile platforms installed in vehicles. The steps of application distribution have been studied in detail. We have identified key attacks (e.g. malware, spamming and phishing, software attack and threat to location privacy) for dense VANET and two attack scenarios for sparse VANET. It has been shown that attacks can be launched by distributing malicious applications and injecting malicious codes to On Board Unit (OBU) by exploiting OBU software security holes. Consequences of such security attacks have been described. Finally, countermeasures including the concepts of sandbox have also been presented in depth.

  4. Ocular injuries from flying bottle caps.

    PubMed

    Fonseka, C

    1993-12-01

    Three cases of serious eye injury are described from flying metal caps of carbonated drink bottles. The injuries occurred while attempting to open the bottle in an unconventional and dangerous way. Though injuries from flying bottle caps have been described before, they have occurred when the bottle exploded. This is the first report of eye injuries caused by bottle caps while opening and are similar to the injuries caused by champagne corks. PMID:8143337

  5. Measurement of Altitude in Blind Flying

    NASA Technical Reports Server (NTRS)

    Brombacher, W G

    1934-01-01

    In this note, instruments for measuring altitude and rate of change of altitude in blind flying and landing of aircraft and their performance are discussed. Of those indicating the altitude above ground level, the sonic altimeter is the most promising. Its present bulk, intermittent operation, and more or less unsatisfactory means of indication are serious drawbacks to its use. The sensitive type aneroid altimeter is also discussed and errors in flying at a pressure level and in landing are discussed in detail.

  6. Antipredator behavior of the new mass-reared unisexual strain of the Mexican Fruit Fly.

    PubMed

    González-López, G I; Rao, D; Díaz-Fleischer, F; Orozco-Dávila, D; Pérez-Staples, D

    2016-06-01

    Tephritid pests controlled through the sterile insect technique (SIT) are mass-reared and subsequently released in affected areas. Several quality parameters are currently used to test adults, but none take into account interactions with a predator. When sterile males are released in the field, they will need to avoid predators until they reach sexual maturity and survive long enough to mate with wild females. Spiders are one of the most common predators that flies may encounter in release sites. In this study, we evaluated the antipredator behavior of a mass-reared sterile unisexual strain ('Tapachula-7') of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae) against their spider predators. We sampled spiders in citrus trees to determine which families could be more common. We established the baseline activity rates of sterile Tapachula-7 (Tap-7) flies in comparison with wild flies. We also tested the behavior of the fertile and sterile bisexual strain and wild flies against hunting spiders (Family Salticidae) and orb building spiders (Family Tetragnathidae). We recorded 18 spider families, with Salticidae being the most dominant. Tap-7 flies diminished their activity in comparison with wild males at 1800 h but showed similar activity levels earlier in the day. When exposed to orb-web spiders (Leucauge venusta), Tap-7, fertile and sterile males from the bisexual strain had similar rates of survival, but Tap-7 males showed lower survival than wild males. Against hunting spiders (Phidippus audax), wild males had higher probability of defensive wing displays, but there was no difference in spider attack rates. In general, sterile Tap -7 males performed as well as males from the bisexual strain, although they had lower survival than wild males. This could be due to either mass-rearing and/or irradiation effects. We recommend the use of the defensive wing display behavior as a quality parameter and propose a rapid and effective method to evaluate fly

  7. Fruit flies and intellectual disability

    PubMed Central

    Bolduc, François V.; Tully, Tim

    2011-01-01

    Mental retardation—known more commonly nowadays as intellectual disability—is a severe neurological condition affecting up to 3% of the general population. As a result of the analysis of familial cases and recent advances in clinical genetic testing, great strides have been made in our understanding of the genetic etiologies of mental retardation. Nonetheless, no treatment is currently clinically available to patients suffering from intellectual disability. Several animal models have been used in the study of memory and cognition. Established paradigms in Drosophila have recently captured cognitive defects in fly mutants for orthologs of genes involved in human intellectual disability. We review here three protocols designed to understand the molecular genetic basis of learning and memory in Drosophila and the genes identified so far with relation to mental retardation. In addition, we explore the mental retardation genes for which evidence of neuronal dysfunction other than memory has been established in Drosophila. Finally, we summarize the findings in Drosophila for mental retardation genes for which no neuronal information is yet available. All in all, this review illustrates the impressive overlap between genes identified in human mental retardation and genes involved in physiological learning and memory. PMID:19182539

  8. Relativistic Tennis Using Flying Mirror

    SciTech Connect

    Pirozhkov, A. S.; Kando, M.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Kimura, T.; Kato, Y.; Tajima, T.; Esirkepov, T. Zh.; Bulanov, S. V.

    2008-06-24

    Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic 'flying mirror', which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of {approx_equal}4-6x10{sup 19} cm{sup -3}. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are {approx}55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3x10{sup 7} photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.

  9. How flies clean their eyes

    NASA Astrophysics Data System (ADS)

    Amador, Guillermo; Durand, Fabien; Mao, Wenbin; Alexeev, Alexander; Hu, David

    2013-11-01

    Flying insects face a barrage of foreign particles such as dust and pollen, which threaten to coat the insect's eyes and antennae, limiting their sensing abilities. In this study, we elucidate novel aerodynamic and elastic mechanisms by which insects keep these organs clean. The compound eye of many species of insects is covered by an array of short bristles, or setae, evenly spaced between each photoreceptor unit. Among these insect species, setae length is triple their spacing. We conduct numerical simulations and wind tunnel experiments using an insect eye mimic to show this critical setae length reduces shear rate at the eye surface by 80%. Thus, the setae create a stagnant zone in front of the eye, which diverts airflow to reduce deposition of particles. Setae can also act as springboards to catapult accumulated particles. In high speed videography of insects using their legs to clean themselves, we observe deflected setae hurling micron scale particles at accelerations over 100 times earth's gravity. The dual abilities of setae to divert airflow and catapult particles may motivate bio-inspired designs for dust-controlling lenses, sensors, and solar panels.

  10. Space shuttle flying qualities and criteria assessment

    NASA Technical Reports Server (NTRS)

    Myers, T. T.; Johnston, D. E.; Mcruer, Duane T.

    1987-01-01

    Work accomplished under a series of study tasks for the Flying Qualities and Flight Control Systems Design Criteria Experiment (OFQ) of the Shuttle Orbiter Experiments Program (OEX) is summarized. The tasks involved review of applicability of existing flying quality and flight control system specification and criteria for the Shuttle; identification of potentially crucial flying quality deficiencies; dynamic modeling of the Shuttle Orbiter pilot/vehicle system in the terminal flight phases; devising a nonintrusive experimental program for extraction and identification of vehicle dynamics, pilot control strategy, and approach and landing performance metrics, and preparation of an OEX approach to produce a data archive and optimize use of the data to develop flying qualities for future space shuttle craft in general. Analytic modeling of the Orbiter's unconventional closed-loop dynamics in landing, modeling pilot control strategies, verification of vehicle dynamics and pilot control strategy from flight data, review of various existent or proposed aircraft flying quality parameters and criteria in comparison with the unique dynamic characteristics and control aspects of the Shuttle in landing; and finally a summary of conclusions and recommendations for developing flying quality criteria and design guides for future Shuttle craft.

  11. Understanding fly-ear inspired directional microphones

    NASA Astrophysics Data System (ADS)

    Liu, Haijun; Zhang, Xuming; Yu, Miao

    2009-03-01

    In this article, the equivalent two-degree-of-freedom (2-DOF) model for the hypersensitive ear of fly Ormia ocharacea is revisited. It is found that in addition to the mechanical coupling between the ears, the key to the remarkable directional hearing ability of the fly is the proper contributions of the rocking mode and bending mode of the ear structure. This can serve as the basis for the development of fly-ear inspired directional microphones. New insights are also provided to establish the connection between the mechanics of the fly ear and the prior biological experiments, which reveals that the fly ear is a nature-designed optimal structure that might have evolved to best perform its localization task at 5 kHz. Based on this understanding, a new design of the fly-ear inspired directional microphone is presented and a corresponding normalized continuum mechanics model is derived. Parametric studies are carried out to study the influence of the identified non-dimensional parameters on the microphone performance. Directional microphones are developed to verify the understanding and concept. This study provides a theoretical guidance to develop miniature bio-inspired directional microphones, and can impact many fronts that require miniature directional microphones.

  12. Wolbachia in Anastrepha fruit flies (Diptera: Tephritidae).

    PubMed

    Coscrato, Virginia E; Braz, Antônio S K; P Perondini, André L; Selivon, Denise; Marino, Celso L

    2009-09-01

    Endosymbiotic bacteria of the genus Wolbachia are widespread among arthropods and cause a variety of reproductive abnormalities, such as cytoplasmic incompatibility, thelytokous parthenogenesis, male-killing, and host feminization. In this study, we used three sets of Wolbachia-specific primers (16S rDNA, ftsZ, and wsp) in conjunction with the polymerase chain reaction (PCR), cloning and sequencing to study the infection of fruit flies (Anastrepha spp. and Ceratitis capitata) by Wolbachia. The flies were collected at several localities in Brazil and at Guayaquil, Ecuador. All of the fruit flies studied were infected with Wolbachia supergroup A, in agreement with the high prevalence of this group in South America. Phylogenetic analysis showed that the wsp gene was the most sensitive gene for studying the relationships among Wolbachia strains. The Wolbachia sequences detected in these fruit flies were similar to those such as wMel reported for other fruit flies. These results show that the infection of Anastrepha fruit flies by Wolbachia is much more widespread than previously thought. PMID:19536597

  13. The Killer Fly Hunger Games: Target Size and Speed Predict Decision to Pursuit

    PubMed Central

    Wardill, Trevor J.; Knowles, Katie; Barlow, Laura; Tapia, Gervasio; Nordström, Karin; Olberg, Robert M.; Gonzalez-Bellido, Paloma T.

    2015-01-01

    Predatory animals have evolved to optimally detect their prey using exquisite sensory systems such as vision, olfaction and hearing. It may not be so surprising that vertebrates, with large central nervous systems, excel at predatory behaviors. More striking is the fact that many tiny insects, with their miniscule brains and scaled down nerve cords, are also ferocious, highly successful predators. For predation, it is important to determine whether a prey is suitable before initiating pursuit. This is paramount since pursuing a prey that is too large to capture, subdue or dispatch will generate a substantial metabolic cost (in the form of muscle output) without any chance of metabolic gain (in the form of food). In addition, during all pursuits, the predator breaks its potential camouflage and thus runs the risk of becoming prey itself. Many insects use their eyes to initially detect and subsequently pursue prey. Dragonflies, which are extremely efficient predators, therefore have huge eyes with relatively high spatial resolution that allow efficient prey size estimation before initiating pursuit. However, much smaller insects, such as killer flies, also visualize and successfully pursue prey. This is an impressive behavior since the small size of the killer fly naturally limits the neural capacity and also the spatial resolution provided by the compound eye. Despite this, we here show that killer flies efficiently pursue natural (Drosophila melanogaster) and artificial (beads) prey. The natural pursuits are initiated at a distance of 7.9 ± 2.9 cm, which we show is too far away to allow for distance estimation using binocular disparities. Moreover, we show that rather than estimating absolute prey size prior to launching the attack, as dragonflies do, killer flies attack with high probability when the ratio of the prey's subtended retinal velocity and retinal size is 0.37. We also show that killer flies will respond to a stimulus of an angular size that is smaller

  14. Chemical stability of geopolymers containing municipal solid waste incinerator fly ash.

    PubMed

    Lancellotti, Isabella; Kamseu, Elie; Michelazzi, Marco; Barbieri, Luisa; Corradi, Anna; Leonelli, Cristina

    2010-04-01

    Municipal solid waste incinerators every year produce tons of fly ashes which, differently from coal fly ashes, contain large amounts of toxic substances (heavy metals, dioxins, furans). The stabilization/solidification (S/S) technology known as geopolymerization is proposed with the purpose to bond physically and chemically incinerator fly ashes (IFA) in a solid matrix, in order to reduce pollutant mobility. The chemical stability of geopolymers with Si/Al ratio of 1.8-1.9 and Na/Al ratio of 1.0, synthesized by alkali activation of metakaolin and the addition of 20wt% of two different kinds of IFA, is presented. The concentration of the alkaline solution, water to solid ratio and curing process have been optimized. The room temperature consolidation of IFA containing geopolymers has been tested for leachability in water for 1day, accordingly to EN 12457 regulation and extended to 7days to increase the water attack on solid granules. Leachable metals in the test solution, determined by ICP_AES, fall within limit values set by regulation for non-dangerous waste landfill disposal. Geopolymeric matrix evolution with leaching time has been also evaluated in terms of pH and electrical conductivity increase in solution. PMID:19879748

  15. Commercial and naturally occurring fly parasitoids (Hymenoptera: Pteromalidae) as biological control agents of stable flies and house flies (Diptera: Muscidae) on California dairies.

    PubMed

    Meyer, J A; Mullens, B A; Cyr, T L; Stokes, C

    1990-06-01

    Filth fly parasites reared by commercial insectaries were released on two dairies (MO, DG) in southern California to determine their effect on populations of house flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.). Spalangia endius Walker, Muscidifurax raptorellus Kogan and Legner, and Muscidifurax zaraptor Kogan and Legner were released on the MO dairy from 1985 to 1987 in varying quantities. Parasitism by Muscidifurax zaraptor on the MO dairy was significantly higher (P less than 0.05) from the field-collected stable fly (4.4%) and house fly (12.5%) pupae, compared with a control dairy (0.1%, stable fly; 1.3%, house fly). Muscidifurax zaraptor, released from April through October during 1987 on the DG dairy (350,000 per month), was not recovered in a significantly higher proportion from either fly species relative to the corresponding control dairy. No specimens of Muscidifurax raptorellus were recovered from the MO dairy. Parasite treatments had no apparent effect on adult populations of either fly species or on overall parasitism rate of field-collected stable fly (16.8%, MO; 17.2%, DG) and house fly (23.3%, MO; 20.9%, DG) pupae. Spalangia spp. were the predominant parasites recovered from field-collected stable fly and house fly pupae on all four dairies. Sentinel house fly pupae placed in fly-breeding sites on both release dairies were parasitized at a significantly higher rate, as compared with sentinel pupae on control dairies. The generic composition of parasites emerging from sentinel house fly pupae was 20.6% Spalangia spp. and 73.2% Muscidifurax spp., whereas in field-collected house fly pupae, Spalangia spp. and Muscidifurax spp. constituted 74.3 and 19.6% of the parasites, respectively. PMID:2376639

  16. Leading edge vortex in a slow-flying passerine

    PubMed Central

    Muijres, Florian T.; Johansson, L. Christoffer; Hedenström, Anders

    2012-01-01

    Most hovering animals, such as insects and hummingbirds, enhance lift by producing leading edge vortices (LEVs) and by using both the downstroke and upstroke for lift production. By contrast, most hovering passerine birds primarily use the downstroke to generate lift. To compensate for the nearly inactive upstroke, weight support during the downstroke needs to be relatively higher in passerines when compared with, e.g. hummingbirds. Here we show, by capturing the airflow around the wing of a freely flying pied flycatcher, that passerines may use LEVs during the downstroke to increase lift. The LEV contributes up to 49 per cent to weight support, which is three times higher than in hummingbirds, suggesting that avian hoverers compensate for the nearly inactive upstroke by generating stronger LEVs. Contrary to other animals, the LEV strength in the flycatcher is lowest near the wing tip, instead of highest. This is correlated with a spanwise reduction of the wing's angle-of-attack, partly owing to upward bending of primary feathers. We suggest that this helps to delay bursting and shedding of the particularly strong LEV in passerines. PMID:22417792

  17. Extract of the seeds of the plant Vitex agnus castus proven to be highly efficacious as a repellent against ticks, fleas, mosquitoes and biting flies.

    PubMed

    Mehlhorn, Heinz; Schmahl, Günter; Schmidt, Jürgen

    2005-03-01

    About 70 plant extracts were tested for their ability to repel the attacks of blood-sucking arthropods. It was found that a CO2 extract of the seeds of the Mediterranean plant Vitex agnus castus (monk's pepper) can be used as a spray to keep away especially Ixodes ricinus and Rhipicephalus sanguineus ticks from animals and humans for at least 6 h. In addition mosquitoes, biting flies and fleas are also repelled for about 6 h. PMID:15682335

  18. Investigation of the Flying Mock-Up of Consolidated Vultee XP-92 Airplane in the Ames 40- by 80-Foot Wind Tunnel: Pressure Distributions

    NASA Technical Reports Server (NTRS)

    Graham, David

    1948-01-01

    This report contains the results of the wind tunnel investigation of the pressure distribution on the flying mock-up of the Consolidated Vultee XP-92 airplane. Data are presented for the pressure distribution over the wing, vertical tail and the fuselage, and for the pressure loss and rate of flow through the ducted fuselage. Data are also presented for the calibration of two airspeed indicators, and for the calibration of angle-of-attack and sideslip-angle indicator vanes.

  19. Wing and body kinematics of forward flight in drone-flies.

    PubMed

    Meng, Xue Guang; Sun, Mao

    2016-01-01

    Here, we present a detailed analysis of the wing and body kinematics in drone-flies in free flight over a range of speeds from hovering to about 8.5 m s(-1). The kinematics was measured by high-speed video techniques. As the speed increased, the body angle decreased and the stroke plane angle increased; the wingbeat frequency changed little; the stroke amplitude first decreased and then increased; the ratio of the downstroke duration to the upstroke duration increased; the mean positional angle increased at lower speeds but changed little at speeds above 3 m s(-1). At a speed above about 1.5 m s(-1), wing rotation at supination was delayed and that at pronation was advanced, and consequently the wing rotations were mostly performed in the upstroke. In the downstroke, the relative velocity of the wing increased and the effective angle of attack decreased with speed; in the upstroke, they both decreased with speed at lower speeds, and at higher speeds, the relative velocity became larger but the effective angle of attack became very small. As speed increased, the increasing inclination of the stroke plane ensured that the effective angle of attack in the upstroke would not become negative, and that the wing was in suitable orientations for vertical-force and thrust production. PMID:27526336

  20. The relationship between 3-D kinematics and gliding performance in the southern flying squirrel, Glaucomys volans.

    PubMed

    Bishop, Kristin L

    2006-02-01

    Gliding is the simplest form of flight, yet relatively little is known about its mechanics in animals. The goal of this study was to describe the body position and performance of a gliding mammal and to identify correlates between kinematics and aerodynamic performance. To do this, I used a pair of high-speed digital cameras to record a portion of the middle of glides by southern flying squirrels, Glaucomys volans. The squirrels launched from a height of 4 m and landed on a vertical pole. Reflective markers were applied to anatomical landmarks and the 3-D coordinates of these points were computed to describe the kinematics of the glides. From these data I estimated the lift and drag generated during the glide, and correlated these variables with gliding performance as measured by glide angle, glide speed and stability. In the majority of the glide sequences the squirrels accelerated in the downward direction and accelerated horizontally forward as they moved through the calibrated volume in the middle of the glide trajectory, rather than exhibiting a steady glide in which the body weight is balanced by the resultant aerodynamic force. Compared to human engineered airfoils, the angles of attack used by the squirrels were unexpectedly high, ranging from 35.4 degrees to 53.5 degrees , far above the angle of attack at which an aircraft wing would typically stall. As expected based on aerodynamic theory, there was a negative correlation between angle of attack and lift coefficient, indicating that the wings are stalled, and a positive correlation between angle of attack and drag coefficient. Also as expected, there was a negative correlation between lift-to-drag ratio and angle of attack, as increasing angle of attack produced both less lift and more drag. Within glides, there was a strong correlation between nose-down pitching rotations and limb movements that tended to increase the angle of attack of the wing membrane, suggesting that the animals actively control

  1. Resistance of geopolymer materials to acid attack

    SciTech Connect

    Bakharev, T

    2005-04-01

    This article presents an investigation into durability of geopolymer materials manufactured using a class F fly ash (FA) and alkaline activators when exposed to 5% solutions of acetic and sulfuric acids. The main parameters studied were the evolution of weight, compressive strength, products of degradation and microstructural changes. The degradation was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The performance of geopolymer materials when exposed to acid solutions was superior to ordinary Portland cement (OPC) paste. However, significant degradation of strength was observed in some geopolymer materials prepared with sodium silicate and with a mixture of sodium hydroxide and potassium hydroxide as activators. The deterioration observed was connected to depolymerisation of the aluminosilicate polymers in acidic media and formation of zeolites, which in some cases lead to a significant loss of strength. The best performance was observed in the geopolymer material prepared with sodium hydroxide and cured at elevated temperature, which was attributed to a more stable cross-linked aluminosilicate polymer structure formed in this material.

  2. Oral and Topical Toxicity of Fipronil to Melon Fly and Oriental Fruit Fly (Diptera: Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: The objective of this study was to develop basic oral and topical toxicity data for Fipronil in Solulys protein bait to wild melon fly, Bactrocera cucurbitae (Coquillett) and the oriental fruit fly, Bactrocera dorsalis (Hendel). RESULTS: For the oral study, both females and males were ...

  3. Filthy Flies? Experiments to Test Flies as Vectors of Bacterial Disease

    ERIC Educational Resources Information Center

    Shaffer, Julie J.; Warner, Kasey Jo; Hoback, W. Wyatt

    2007-01-01

    For more than 75 years, flies and other insects have been known to serve as mechanical vectors of infectious disease (Hegner, 1926). Flies have been shown to harbor over 100 different species of potentially pathogenic microorganisms and are known to transmit more than 65 infectious diseases (Greenberg, 1965). This laboratory exercise is a simple…

  4. Expression of defensin paralogs across house fly life history: insights into fly-microbe interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    House flies have a life-long association with microbe-rich environments. Larvae directly ingest bacteria in decaying substrates utilizing them for nutritional purposes. Adult house flies ephemerally associate with microbes, ingesting them either by direct feeding or indirectly during grooming. The h...

  5. Effectiveness of fly traps and baits at three primary fly sites on Florida dairy farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The house fly, Musca domestica L., is a ubiquitous pest on dairies. They can cause production losses from fly worry, disperse from farms to nearby towns, transmit diseases like pinkeye, and carry pathogens like E. coli O157:H7. The calf raising, commodity barn/feed storage, and feeding barn areas te...

  6. Heart Attack or Sudden Cardiac Arrest: How Are They Different?

    MedlinePlus

    ... a person loses consciousness and has no pulse. Death occurs within minutes if the victim does not receive treatment. What is the link? These two distinct heart conditions are linked. Sudden cardiac arrest can occur after a heart attack, or during recovery. Heart attacks increase the risk ...

  7. Are Risk Assessments of a Terrorist Attack Coherent?

    ERIC Educational Resources Information Center

    Mandel, David R.

    2005-01-01

    Four experiments examined 3 types of violations of coherence criteria in risk assessments of a terrorist attack. First, the requirement that extensionally equivalent descriptions be assigned the same probability (i.e., additivity) was violated. Unpacking descriptions of an attack into subtypes led to an increase in assessed risk. Second,…

  8. New Attacks on Animal Researchers Provoke Anger and Worry

    ERIC Educational Resources Information Center

    Guterman, Lila

    2008-01-01

    This article reports on firebomb attacks at the homes of two animal researchers which have provoked anger and unease. The firebomb attacks, which set the home of a neuroscientist at the University of California at Santa Cruz aflame and destroyed a car parked in the driveway of another university researcher's home, have left researchers and…

  9. The Icatibant Outcome Survey: treatment of laryngeal angioedema attacks

    PubMed Central

    Aberer, Werner; Bouillet, Laurence; Caballero, Teresa; Maurer, Marcus; Fabien, Vincent; Zanichelli, Andrea

    2016-01-01

    Objective To characterize the management and outcomes of life-threatening laryngeal attacks of hereditary angioedema (HAE) treated with icatibant in the observational Icatibant Outcome Survey (NCT01034969) registry. Methods This retrospective analysis was based on data from patients with HAE type I/II who received healthcare professional-administered or self-administered icatibant to treat laryngeal attacks between September 2008 and May 2013. Results Twenty centers in seven countries contributed data. Overall, 42 patients with HAE experienced 67 icatibant-treated laryngeal attacks. Icatibant was self-administered for 62.3% of attacks (healthcare professional-administered, 37.7%). One icatibant injection was used for 87.9% of attacks, with rescue or concomitant medication used for 9.0%. The median time to treatment was 2.0 h (n=31 attacks) and the median time to resolution was 6.0 h (n=35 attacks). Conclusions This analysis describes successful use of icatibant for the treatment of laryngeal HAE attacks in a real-world setting. PMID:27116379

  10. Detecting Distributed SQL Injection Attacks in a Eucalyptus Cloud Environment

    NASA Technical Reports Server (NTRS)

    Kebert, Alan; Barnejee, Bikramjit; Solano, Juan; Solano, Wanda

    2013-01-01

    The cloud computing environment offers malicious users the ability to spawn multiple instances of cloud nodes that are similar to virtual machines, except that they can have separate external IP addresses. In this paper we demonstrate how this ability can be exploited by an attacker to distribute his/her attack, in particular SQL injection attacks, in such a way that an intrusion detection system (IDS) could fail to identify this attack. To demonstrate this, we set up a small private cloud, established a vulnerable website in one instance, and placed an IDS within the cloud to monitor the network traffic. We found that an attacker could quite easily defeat the IDS by periodically altering its IP address. To detect such an attacker, we propose to use multi-agent plan recognition, where the multiple source IPs are considered as different agents who are mounting a collaborative attack. We show that such a formulation of this problem yields a more sophisticated approach to detecting SQL injection attacks within a cloud computing environment.

  11. Examining Willingness to Attack Critical Infrastructure Online and Offline

    ERIC Educational Resources Information Center

    Holt, Thomas J.; Kilger, Max

    2012-01-01

    The continuing adoption of technologies by the general public coupled with the expanding reliance of critical infrastructures connected through the Internet has created unique opportunities for attacks by civilians and nation-states alike. Although governments are increasingly focusing on policies to deter nation-state level attacks, it is unclear…

  12. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to manufacture, construct, and operate a...

  13. Sequential defense against random and intentional attacks in complex networks.

    PubMed

    Chen, Pin-Yu; Cheng, Shin-Ming

    2015-02-01

    Network robustness against attacks is one of the most fundamental researches in network science as it is closely associated with the reliability and functionality of various networking paradigms. However, despite the study on intrinsic topological vulnerabilities to node removals, little is known on the network robustness when network defense mechanisms are implemented, especially for networked engineering systems equipped with detection capabilities. In this paper, a sequential defense mechanism is first proposed in complex networks for attack inference and vulnerability assessment, where the data fusion center sequentially infers the presence of an attack based on the binary attack status reported from the nodes in the network. The network robustness is evaluated in terms of the ability to identify the attack prior to network disruption under two major attack schemes, i.e., random and intentional attacks. We provide a parametric plug-in model for performance evaluation on the proposed mechanism and validate its effectiveness and reliability via canonical complex network models and real-world large-scale network topology. The results show that the sequential defense mechanism greatly improves the network robustness and mitigates the possibility of network disruption by acquiring limited attack status information from a small subset of nodes in the network. PMID:25768550

  14. Sequential defense against random and intentional attacks in complex networks

    NASA Astrophysics Data System (ADS)

    Chen, Pin-Yu; Cheng, Shin-Ming

    2015-02-01

    Network robustness against attacks is one of the most fundamental researches in network science as it is closely associated with the reliability and functionality of various networking paradigms. However, despite the study on intrinsic topological vulnerabilities to node removals, little is known on the network robustness when network defense mechanisms are implemented, especially for networked engineering systems equipped with detection capabilities. In this paper, a sequential defense mechanism is first proposed in complex networks for attack inference and vulnerability assessment, where the data fusion center sequentially infers the presence of an attack based on the binary attack status reported from the nodes in the network. The network robustness is evaluated in terms of the ability to identify the attack prior to network disruption under two major attack schemes, i.e., random and intentional attacks. We provide a parametric plug-in model for performance evaluation on the proposed mechanism and validate its effectiveness and reliability via canonical complex network models and real-world large-scale network topology. The results show that the sequential defense mechanism greatly improves the network robustness and mitigates the possibility of network disruption by acquiring limited attack status information from a small subset of nodes in the network.

  15. Is There Anybody There? A Psychodynamic View of Panic Attack.

    ERIC Educational Resources Information Center

    Rizq, Rosemary

    2002-01-01

    Presents a process analysis of a psychodynamic intervention for a client with panic attacks. Discusses how a psychodynamic understanding of the complex etiology of the client's panic attacks that ultimately produced improved coping skills and a subjective sense of improvement for her. Process analysis is used to illustrate the theoretical base,…

  16. Israeli Adolescents' Coping Strategies in Relation to Terrorist Attacks

    ERIC Educational Resources Information Center

    Tatar, Moshe; Amram, Sima

    2007-01-01

    Exposure to terrorism seriously threatens the well-being of children and adolescents. Israeli citizens have witnessed massive ongoing terrorist attacks during the last few years. The present research, conducted among 330 Israeli adolescents, examined coping strategies in relation to terrorist attacks. We found that adolescents utilize more…

  17. [Banana tree pests attacking Heliconia latispatha Benth. (Heliconiaceae)].

    PubMed

    Watanabe, Maria A

    2007-01-01

    In mid-May 2005, the caterpillars Antichloris eriphia (Fabr.) (Lepidoptera: Arctiidae) and Calligo illioneus (Cramer) (Lepidoptera: Nymphalidae) which are banana tree pests, were found attacking six-month old stalks of Heliconia latispatha Benth., planted near a banana tree plantation in Jaguariuna, SP, Brazil. The attack by C. illioneus is observed by the first time in Brazil. PMID:17607468

  18. Effectiveness of the Call in Beach Volleyball Attacking Play

    PubMed Central

    Künzell, Stefan; Schweikart, Florian; Köhn, Daniel; Schläppi-Lienhard, Olivia

    2014-01-01

    In beach volleyball the setter has the opportunity to give her or his hitter a “call”. The call intends that the setter suggests to her or his partner where to place the attack in the opponent’s court. The effectiveness of a call is still unknown. We investigated the women’s and men’s Swiss National Beach Volleyball Championships in 2011 and analyzed 2185 attacks. We found large differences between female and male players. While men called in only 38.4% of attacks, women used calls in 85.5% of attacks. If the male players followed a given call, 63% of the attacks were successful. The success rate of attacks without any call was 55.8% and 47.6% when the call was ignored. These differences were not significant (χ2(2) = 4.55, p = 0.103). In women’s beach volleyball, the rate of successful attacks was 61.5% when a call was followed, 35% for attacks without a call, and 42.6% when a call was ignored. The differences were highly significant (χ2(2) = 23.42, p < 0.0005). Taking into account the findings of the present study, we suggested that the call was effective in women’s beach volleyball, while its effect in men’s game was unclear. Considering the quality of calls we indicate that there is a significant potential to increase the effectiveness of a call. PMID:25713679

  19. Effectiveness of the call in beach volleyball attacking play.

    PubMed

    Künzell, Stefan; Schweikart, Florian; Köhn, Daniel; Schläppi-Lienhard, Olivia

    2014-12-01

    In beach volleyball the setter has the opportunity to give her or his hitter a "call". The call intends that the setter suggests to her or his partner where to place the attack in the opponent's court. The effectiveness of a call is still unknown. We investigated the women's and men's Swiss National Beach Volleyball Championships in 2011 and analyzed 2185 attacks. We found large differences between female and male players. While men called in only 38.4% of attacks, women used calls in 85.5% of attacks. If the male players followed a given call, 63% of the attacks were successful. The success rate of attacks without any call was 55.8% and 47.6% when the call was ignored. These differences were not significant (χ(2)(2) = 4.55, p = 0.103). In women's beach volleyball, the rate of successful attacks was 61.5% when a call was followed, 35% for attacks without a call, and 42.6% when a call was ignored. The differences were highly significant (χ(2)(2) = 23.42, p < 0.0005). Taking into account the findings of the present study, we suggested that the call was effective in women's beach volleyball, while its effect in men's game was unclear. Considering the quality of calls we indicate that there is a significant potential to increase the effectiveness of a call. PMID:25713679

  20. "Dateline NBC"'s Persuasive Attack on Wal-Mart.

    ERIC Educational Resources Information Center

    Benoit, William L.; Dorries, Bruce

    1996-01-01

    Develops a typology of persuasive attack strategies. Identifies two key components of persuasive attack: responsibility and offensiveness. Describes several strategies for intensifying each of these elements. Applies this analysis to "Dateline NBC"'s allegations that Wal-Mart's "Buy American" campaign was deceptive. Concludes that "Dateline NBC'"s…

  1. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to...

  2. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to...

  3. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to...

  4. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to...

  5. Hereditary Angioedema Attacks: Local Swelling at Multiple Sites.

    PubMed

    Hofman, Zonne L M; Relan, Anurag; Hack, C Erik

    2016-02-01

    Hereditary angioedema (HAE) patients experience recurrent local swelling in various parts of the body including painful swelling of the intestine and life-threatening laryngeal oedema. Most HAE literature is about attacks located in one anatomical site, though it is mentioned that HAE attacks may also involve multiple anatomical sites simultaneously. A detailed description of such multi-location attacks is currently lacking. This study investigated the occurrence, severity and clinical course of HAE attacks with multiple anatomical locations. HAE patients included in a clinical database of recombinant human C1-inhibitor (rhC1INH) studies were evaluated. Visual analog scale scores filled out by the patients for various symptoms at various locations and investigator symptoms scores during the attack were analysed. Data of 219 eligible attacks in 119 patients was analysed. Thirty-three patients (28%) had symptoms at multiple locations in anatomically unrelated regions at the same time during their first attack. Up to five simultaneously affected locations were reported. The observation that severe HAE attacks often affect multiple sites in the body suggests that HAE symptoms result from a systemic rather than from a local process as is currently believed. PMID:25527240

  6. Studies on sulfate attack: Mechanisms, test methods, and modeling

    NASA Astrophysics Data System (ADS)

    Santhanam, Manu

    The objective of this research study was to investigate various issues pertaining to the mechanism, testing methods, and modeling of sulfate attack in concrete. The study was divided into the following segments: (1) effect of gypsum formation on the expansion of mortars, (2) attack by the magnesium ion, (3) sulfate attack in the presence of chloride ions---differentiating seawater and groundwater attack, (4) use of admixtures to mitigate sulfate attack---entrained air, sodium citrate, silica fume, and metakaolin, (5) effects of temperature and concentration of the attack solution, (6) development of new test methods using concrete specimens, and (7) modeling of the sulfate attack phenomenon. Mortar specimens using portland cement (PC) and tricalcium silicate (C 3S), with or without mineral admixtures, were prepared and immersed in different sulfate solutions. In addition to this, portland cement concrete specimens were also prepared and subjected to complete and partial immersion in sulfate solutions. Physical measurements, chemical analyses and microstructural studies were performed periodically on the specimens. Gypsum formation was seen to cause expansion of the C3S mortar specimens. Statistical analyses of the data also indicated that the quantity of gypsum was the most significant factor controlling the expansion of mortar bars. The attack by magnesium ion was found to drive the reaction towards the formation of brucite. Decalcification of the C-S-H and its subsequent conversion to the non-cementitious M-S-H was identified as the mechanism of destruction in magnesium sulfate attack. Mineral admixtures were beneficial in combating sodium sulfate attack, while reducing the resistance to magnesium sulfate attack. Air entrainment did not change the measured physical properties, but reduced the visible distress of the mortars. Sodium citrate caused a substantial reduction in the rate of damage of the mortars due to its retarding effect. Temperature and

  7. Optimal attack strategy of complex networks based on tabu search

    NASA Astrophysics Data System (ADS)

    Deng, Ye; Wu, Jun; Tan, Yue-jin

    2016-01-01

    The problem of network disintegration has broad applications and recently has received growing attention, such as network confrontation and disintegration of harmful networks. This paper presents an optimized attack strategy model for complex networks and introduces the tabu search into the network disintegration problem to identify the optimal attack strategy, which is a heuristic optimization algorithm and rarely applied to the study of network robustness. The efficiency of the proposed solution was verified by comparing it with other attack strategies used in various model networks and real-world network. Numerical experiments suggest that our solution can improve the effect of network disintegration and that the "best" choice for node failure attacks can be identified through global searches. Our understanding of the optimal attack strategy may also shed light on a new property of the nodes within network disintegration and deserves additional study.

  8. The Application of Baum-Welch Algorithm in Multistep Attack

    PubMed Central

    Zhang, Yanxue; Zhao, Dongmei; Liu, Jinxing

    2014-01-01

    The biggest difficulty of hidden Markov model applied to multistep attack is the determination of observations. Now the research of the determination of observations is still lacking, and it shows a certain degree of subjectivity. In this regard, we integrate the attack intentions and hidden Markov model (HMM) and support a method to forecasting multistep attack based on hidden Markov model. Firstly, we train the existing hidden Markov model(s) by the Baum-Welch algorithm of HMM. Then we recognize the alert belonging to attack scenarios with the Forward algorithm of HMM. Finally, we forecast the next possible attack sequence with the Viterbi algorithm of HMM. The results of simulation experiments show that the hidden Markov models which have been trained are better than the untrained in recognition and prediction. PMID:24991642

  9. Simulated predator attacks on flocks: a comparison of tactics.

    PubMed

    Demšar, Jure; Lebar Bajec, Iztok

    2014-01-01

    It is not exactly known why birds aggregate in coordinated flocks. The most common hypothesis proposes that the reason is protection from predators. Most of the currently developed examples of individual-based predator-prey models assume predators are attracted to the center of a highly coordinated flock. This proposed attraction of a predator to a flock would appear to be contradictory to an alternate hypothesis that flocks evolved as a protection against predation. In an attempt to resolve this apparent conflict, in this article we use a fuzzy individual-based model to study three attack tactics (attack center, attack nearest, attack isolated) and analyze the success of predation on two types of prey (social and individualistic). Our simulations revealed that social flocking (as opposed to individualistic behavior) is the optimal anti-predatory response to predators attacking mainly isolated individuals. PMID:24730766

  10. DDoS Attack Detection Algorithms Based on Entropy Computing

    NASA Astrophysics Data System (ADS)

    Li, Liying; Zhou, Jianying; Xiao, Ning

    Distributed Denial of Service (DDoS) attack poses a severe threat to the Internet. It is difficult to find the exact signature of attacking. Moreover, it is hard to distinguish the difference of an unusual high volume of traffic which is caused by the attack or occurs when a huge number of users occasionally access the target machine at the same time. The entropy detection method is an effective method to detect the DDoS attack. It is mainly used to calculate the distribution randomness of some attributes in the network packets' headers. In this paper, we focus on the detection technology of DDoS attack. We improve the previous entropy detection algorithm, and propose two enhanced detection methods based on cumulative entropy and time, respectively. Experiment results show that these methods could lead to more accurate and effective DDoS detection.

  11. A Taxonomy of Attacks on the DNP3 Protocol

    NASA Astrophysics Data System (ADS)

    East, Samuel; Butts, Jonathan; Papa, Mauricio; Shenoi, Sujeet

    Distributed Network Protocol (DNP3) is the predominant SCADA protocol in the energy sector - more than 75% of North American electric utilities currently use DNP3 for industrial control applications. This paper presents a taxonomy of attacks on the protocol. The attacks are classified based on targets (control center, outstation devices and network/communication paths) and threat categories (interception, interruption, modification and fabrication). To facilitate risk analysis and mitigation strategies, the attacks are associated with the specific DNP3 protocol layers they exploit. Also, the operational impact of the attacks is categorized in terms of three key SCADA objectives: process confi- dentiality, process awareness and process control. The attack taxonomy clarifies the nature and scope of the threats to DNP3 systems, and can provide insights into the relative costs and benefits of implementing mitigation strategies.

  12. Attacks on Bluetooth Security Architecture and Its Countermeasures

    NASA Astrophysics Data System (ADS)

    Iqbal, Mian Muhammad Waseem; Kausar, Firdous; Wahla, Muhammad Arif

    WPANs compliment the traditional IEEE 802.11 wireless networks by facilitating the clients with flexibility in network topologies, higher mobility and relaxed configuration/hardware requirements. Bluetooth, a WPAN technology, is an open standard for short-range radio frequency (RF) communication. However, it is also susceptible to typical security threats found in wireless LANs. This paper discuses some of the attack scenarios against the bluetooth network such as hostile intrusion, active Man-in-the-Middle (MITM) attack using unit key and various forms of denial of service (DoS) attacks. These threats and attacks compromise the confidentiality and availability of bluetooth data and services. This paper proposes an improved security architecture for bluetooth device which provides protection against the above mentioned attacks.

  13. Expected losses, insurability, and benefits from reducing vulnerability to attacks.

    SciTech Connect

    Nozick, Linda Karen; Carlson, Rolf Erik; Turnquist, Mark Alan

    2004-03-01

    A model of malicious attacks against an infrastructure system is developed that uses a network representation of the system structure together with a Hidden Markov Model of an attack at a node of that system and a Markov Decision Process model of attacker strategy across the system as a whole. We use information systems as an illustration, but the analytic structure developed can also apply to attacks against physical facilities or other systems that provide services to customers. This structure provides an explicit mechanism to evaluate expected losses from malicious attacks, and to evaluate changes in those losses that would result from system hardening. Thus, we provide a basis for evaluating the benefits of system hardening. The model also allows investigation of the potential for the purchase of an insurance contract to cover the potential losses when safeguards are breached and the system fails.

  14. Laboratory evaluation of novaluron as a development site treatment for controlling larval horn flies, house flies, and stable flies (Diptera: Muscidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A granular formulation of novaluron (Novaluron 0.2G, 0.2% AI), a newer benzoylphenyl urea insecticide, was evaluated for its efficacy in controlling the larval stage of horn flies, Haematobia irritans (L.), house flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), in cow manure. V...

  15. Prodromes and predictors of migraine attack.

    PubMed

    Rossi, Paolo; Ambrosini, Anna; Buzzi, M Gabriella

    2005-01-01

    Premonitory symptoms of migraine include a wide and heterogeneous collection of cognitive, psychic and physical changes preceding and forewarning of an attack by a few hours to 2-3 days. To date, premonitory symptoms have received little attention in the literature, being treated more as a curiosity than as a primary feature of migraine. This paper provides an extensive critical review of this neglected area of migraine research in the light of the recent advances in our understanding of the pathogenetic mechanisms of migraine. Epidemiological and clinical studies that have investigated the premonitory symptoms of migraine lack scientific rigour, producing conflicting results, whilst genetic and pathophysiological investigations are still in their very early stages. There is evidence supporting the idea that premonitory symptoms could be used as a phenotypical marker to identify subgroups of migraineurs which could show correlations with specific clinical expressions of the disease, genotypes, or responses to treatments. Future studies are needed to clarify the clinical, pathophysiological and therapeutic significance of premonitory symptoms. PMID:16483459

  16. Marine transducing bacteriophage attacking a luminous bacterium.

    PubMed

    Keynan, A; Nealson, K; Sideropoulos, H; Hastings, J W

    1974-08-01

    The isolation and partial characterization of a marine bacteriophage attacking a strain of luminous bacteria is described, including some physical, biological, and genetic properties. It is a DNA phage of density of 1.52 with a long flexible tail and an apparently icosohedral head. With respect to stability in suspension, it has a rather specific requirement for the sodium ion in high concentration; it is further stabilized by the addition of calcium and magnesium ions. These same ions are likewise all required for both good plating efficiency and plaque uniformity. Although it goes through a typical lytic growth cycle (about 45 min), with a burst size of 100, and no stable lysogens have been isolated, it is nevertheless a transducing phage specifically for the tryptophan region, transducing several, but not all, independently isolated Trp(-) auxotrophs to protrophy. No other auxotrophs of a variety of amino acids were transduced by this phage to prototrophy. Phage infection does not change the normal expression of the luminescent system, and light remains at near normal levels until cell lysis occurs. PMID:16789143

  17. Pirate attacks affect Indian Ocean climate research

    NASA Astrophysics Data System (ADS)

    Smith, Shawn R.; Bourassa, Mark A.; Long, Michael

    2011-07-01

    Pirate attacks in the Gulf of Aden and the Indian Ocean off the coast of Somalia nearly doubled from 111 in 2008 to 217 in 2009 [International Maritime Bureau, 2009, International Maritime Bureau, 2010]. Consequently, merchant vessel traffic in the area around Somalia significantly decreased. Many of these merchant vessels carry instruments that record wind and other weather conditions near the ocean surface, and alterations in ship tracks have resulted in a hole sized at about 2.5 million square kilometers in the marine weather-observing network off the coast of Somalia. The data void exists in the formation region of the Somali low-level jet, a wind pattern that is one of the main drivers of the Indian summer monsoon. Further, a stable, multidecadal record has been interrupted, and consequently, long-term analyses of the jet derived from surface wind data are now showing artificial anomalies that will affect efforts by scientists to identify interannual to decadal variations in the climate of the northwestern Indian Ocean.

  18. Node Survival in Networks under Correlated Attacks

    PubMed Central

    Hao, Yan; Armbruster, Dieter; Hütt, Marc-Thorsten

    2015-01-01

    We study the interplay between correlations, dynamics, and networks for repeated attacks on a socio-economic network. As a model system we consider an insurance scheme against disasters that randomly hit nodes, where a node in need receives support from its network neighbors. The model is motivated by gift giving among the Maasai called Osotua. Survival of nodes under different disaster scenarios (uncorrelated, spatially, temporally and spatio-temporally correlated) and for different network architectures are studied with agent-based numerical simulations. We find that the survival rate of a node depends dramatically on the type of correlation of the disasters: Spatially and spatio-temporally correlated disasters increase the survival rate; purely temporally correlated disasters decrease it. The type of correlation also leads to strong inequality among the surviving nodes. We introduce the concept of disaster masking to explain some of the results of our simulations. We also analyze the subsets of the networks that were activated to provide support after fifty years of random disasters. They show qualitative differences for the different disaster scenarios measured by path length, degree, clustering coefficient, and number of cycles. PMID:25932635

  19. Node Survival in Networks under Correlated Attacks.

    PubMed

    Hao, Yan; Armbruster, Dieter; Hütt, Marc-Thorsten

    2015-01-01

    We study the interplay between correlations, dynamics, and networks for repeated attacks on a socio-economic network. As a model system we consider an insurance scheme against disasters that randomly hit nodes, where a node in need receives support from its network neighbors. The model is motivated by gift giving among the Maasai called Osotua. Survival of nodes under different disaster scenarios (uncorrelated, spatially, temporally and spatio-temporally correlated) and for different network architectures are studied with agent-based numerical simulations. We find that the survival rate of a node depends dramatically on the type of correlation of the disasters: Spatially and spatio-temporally correlated disasters increase the survival rate; purely temporally correlated disasters decrease it. The type of correlation also leads to strong inequality among the surviving nodes. We introduce the concept of disaster masking to explain some of the results of our simulations. We also analyze the subsets of the networks that were activated to provide support after fifty years of random disasters. They show qualitative differences for the different disaster scenarios measured by path length, degree, clustering coefficient, and number of cycles. PMID:25932635

  20. Assessment and treatment of nocturnal panic attacks.

    PubMed

    Craske, Michelle G; Tsao, Jennie C I

    2005-06-01

    Nocturnal panic (NP), waking from sleep in a state of panic, is a common occurrence among patients with panic disorder, with 44-71% reporting at least one such attack. NP is a non-REM event that is distinct from sleep terrors, sleep apnea, nightmares or dream-induced arousals. This review outlines recent advances in the characterization of NP, as well as current approaches to the assessment and treatment of NP. In contrast to earlier work, more recent studies suggest that patients with NP do not differ from patients without NP on sleep architecture, sleep physiology, self-reported sleep quality and severity of panic disorder. However, more precise measurement of physiological precipitants and features is warranted. Assessment of NP focuses on ruling out other explanations for NP, with differential diagnosis based on interviews, sleep polysomnography and ambulatory recording of sleep. Psychological treatment (cognitive-behavioral therapy) targets misappraisals of anxiety sensations, hyperventilatory response, and conditioned reactions to internal, physical cues. Recent evidence supports the efficacy of this approach, however, controlled studies on pharmacological agents in the treatment of NP are lacking. Research is needed to examine the effects of combined cognitive-behavioral therapy and medications, compared to medication alone in the treatment of NP. PMID:15893248

  1. Feeding and attraction of non-target flies to spinosad-based fruit fly bait.

    PubMed

    Wang, Xin-Geng; Messing, Russell H

    2006-10-01

    A spinosad-based fruit fly bait, GF-120, has recently become a primary tool for area-wide suppression or eradication of pest tephritid fruit flies. The present study assessed the attraction and feeding of five non-target fly species to GF-120 in Hawaii. These non-target flies include three beneficial tephritid species [Eutreta xanthochaeta (Aldrich), Tetreuaresta obscuriventris (Loew), Ensina sonchi (L.)] introduced for weed biological control, an endemic Hawaiian tephritid [Trupanea dubautiae (Bryan)] (all Diptera: Tephritidae) and the cosmopolitan Drosophila melanogaster Meigen (Diptera: Drosophilidae). All five non-target fly species were susceptible to GF-120, as was the target pest Mediterranean fruit fly Ceratitis capitata (Wiedemann). Feeding on, or even brief tasting of, GF-120 killed all fly species within 2 h. When individual flies were provided with a choice of GF-120 or honey solution, there was no difference in the frequency of first food encounter by E. xanthochaeta, D. melanogaster or C. capitata. The other three non-target species approached honey more often than GF-120 in their first food encounter. Feeding times on GF-120 and honey were not significantly different for D. melanogaster and C. capitata, while the other four non-target species fed longer on honey than on GF-120. There was no significant difference in feeding time on honey versus GF-120 between males and females of each species. These results suggest that area-wide treatment using GF-120 for the purpose of eradication of pest fruit flies has potential negative impacts on these and other non-target fly species in Hawaii. PMID:16835891

  2. Metrics for Assessment of Smart Grid Data Integrity Attacks

    SciTech Connect

    Annarita Giani; Miles McQueen; Russell Bent; Kameshwar Poolla; Mark Hinrichs

    2012-07-01

    There is an emerging consensus that the nation’s electricity grid is vulnerable to cyber attacks. This vulnerability arises from the increasing reliance on using remote measurements, transmitting them over legacy data networks to system operators who make critical decisions based on available data. Data integrity attacks are a class of cyber attacks that involve a compromise of information that is processed by the grid operator. This information can include meter readings of injected power at remote generators, power flows on transmission lines, and relay states. These data integrity attacks have consequences only when the system operator responds to compromised data by redispatching generation under normal or contingency protocols. These consequences include (a) financial losses from sub-optimal economic dispatch to service loads, (b) robustness/resiliency losses from placing the grid at operating points that are at greater risk from contingencies, and (c) systemic losses resulting from cascading failures induced by poor operational choices. This paper is focused on understanding the connections between grid operational procedures and cyber attacks. We first offer two examples to illustrate how data integrity attacks can cause economic and physical damage by misleading operators into taking inappropriate decisions. We then focus on unobservable data integrity attacks involving power meter data. These are coordinated attacks where the compromised data are consistent with the physics of power flow, and are therefore passed by any bad data detection algorithm. We develop metrics to assess the economic impact of these attacks under re-dispatch decisions using optimal power flow methods. These metrics can be use to prioritize the adoption of appropriate countermeasures including PMU placement, encryption, hardware upgrades, and advance attack detection algorithms.

  3. Pre-Attack Symptomatology and Temperament as Predictors of Children's Responses to the September 11 Terrorist Attacks

    ERIC Educational Resources Information Center

    Lengua, Liliana J.; Long, Anna C.; Smith, Kimberlee I.; Meltzoff, Andrew N.

    2005-01-01

    Background: The aims of this study were to assess the psychological response of children following the September 11, 2001 terrorist attacks in New York and Washington, DC and to examine prospective predictors of children's post-attack responses. Method: Children's responses were assessed in a community sample of children in Seattle, Washington,…

  4. Environmental and habitat drivers of relative abundance for a suite of azteca-attacking Pseudacteon phorid flies.

    PubMed

    Reese, Katlynd M; Philpott, Stacy M

    2012-10-01

    Phoridae (Diptera) have widespread impacts on insect communities by limiting host ant behavior. However, phorid-ant interactions may vary with habitat or environmental conditions. Three Pseudacteon species parasitize Azteca instabilis Fr. Smith, a common ant in coffee agroecosystems, and limit A. instabilis foraging, indirectly benefiting other insects. However, little is known about how phorid abundance, behavior, and effects change with environmental conditions. In shaded coffee systems, coffee (Coffea arabica L.) grows under a range of shade conditions and management changes affect species interactions. For example, Pseudacteon spp. more strongly limit A. instabilis foraging in low-shade coffee habitats. We sampled relative abundance of three phorid species around A. instabilis nests in three coffee habitats varying in shade management during dry and wet seasons. We measured canopy cover, tree richness, tree density, leaf litter depth, and number of nearby trees with A. instabilis to determine whether these habitat factors correlate with phorid abundance. P. laciniosus Brown was the most abundant phorid in both seasons. Phorid relative abundance did not differ by habitat, but did differ by season. P. laciniosus accounted for a higher proportion of phorids in the wet season (91.4%) than in the dry season (78.9%), and P. planidorsalis Brown accounted for a larger percent in the dry season (21.1%) than in the wet season (7.3%). Phorid composition did not differ with habitat type, and none of the measured environmental variables correlated with changes in phorid composition. Thus, phorids in coffee agroecosystems respond to large seasonal differences, but not differences between coffee habitats. PMID:23068166

  5. Review of parasitic wasps and flies (Hymenoptera, Diptera) attacking Limacodidae (Lepidoptera) in North America, with a key to genera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hymenopteran and dipteran parasitoids of slug caterpillars (Lepidoptera: Limacodidae) from North America are reviewed and an illustrated key to 17 genera is presented. Limacodid surveys and rearing were conducted by the Lill lab (JTL, SMM, TMS) during the summer months of 2004–2009 as part of their...

  6. Bionomics of the face fly, Musca autumnalis.

    PubMed

    Krafsur, E S; Moon, R D

    1997-01-01

    The face fly was introduced from the Palearctic region and spread across North America in 20 years after World War II. Adults feed on cattle and horses, and larvae develop in fresh cattle dung. Little genetic differentiation appears between European and North American populations and among regions within North America. After an autumnally initiated diapause, overwintered flies emerge in spring and reproduce through late spring and summer. Generations after the first overlap, and age structure develops toward a stable age distribution. After three to ten generations, depending on weather, facultative diapause interrupts host feeding and oogenesis, and flies with hypertrophied fat body enter overwintering hibernaculae. Life table statistics and factors affecting population growth and diapause are reviewed. Early views on the fly's effects on animal productivity may have been exaggerated. On-farm control by conventional means has not been effective because of the fly's population dynamics and mobility. We suggest that the alternatives of classical biological control and area-wide control with the sterile insect technique should be considered. PMID:9017900

  7. Reconstructing the behavior of walking fruit flies

    NASA Astrophysics Data System (ADS)

    Berman, Gordon; Bialek, William; Shaevitz, Joshua

    2010-03-01

    Over the past century, the fruit fly Drosophila melanogaster has arisen as almost a lingua franca in the study of animal behavior, having been utilized to study questions in fields as diverse as sleep deprivation, aging, and drug abuse, amongst many others. Accordingly, much is known about what can be done to manipulate these organisms genetically, behaviorally, and physiologically. Most of the behavioral work on this system to this point has been experiments where the flies in question have been given a choice between some discrete set of pre-defined behaviors. Our aim, however, is simply to spend some time with a cadre of flies, using techniques from nonlinear dynamics, statistical physics, and machine learning in an attempt to reconstruct and gain understanding into their behavior. More specifically, we use a multi-camera set-up combined with a motion tracking stage in order to obtain long time-series of walking fruit flies moving about a glass plate. This experimental system serves as a test-bed for analytical, statistical, and computational techniques for studying animal behavior. In particular, we attempt to reconstruct the natural modes of behavior for a fruit fly through a data-driven approach in a manner inspired by recent work in C. elegans and cockroaches.

  8. High chromosomal variation in wild horn fly Haematobia irritans (Linnaeus) (Diptera, Muscidae) populations

    PubMed Central

    Forneris, Natalia S.; Otero, Gabriel; Pereyra, Ana; Repetto, Gustavo; Rabossi, Alejandro; Quesada-Allué, Luis A.; Basso, Alicia L.

    2015-01-01

    Abstract The horn fly, Haematobia irritans is an obligate haematophagous cosmopolitan insect pest. The first reports of attacks on livestock by Haematobia irritans in Argentina and Uruguay occurred in 1991, and since 1993 it is considered an economically important pest. Knowledge on the genetic characteristics of the horn fly increases our understanding of the phenotypes resistant to insecticides that repeatedly develop in these insects. The karyotype of Haematobia irritans, as previously described using flies from an inbred colony, shows a chromosome complement of 2n=10 without heterochromosomes (sex chromosomes). In this study, we analyze for the first time the chromosome structure and variation of four wild populations of Haematobia irritans recently established in the Southern Cone of South America, collected in Argentina and Uruguay. In these wild type populations, we confirmed and characterized the previously published “standard” karyotype of 2n=10 without sex chromosomes; however, surprisingly a supernumerary element, called B-chromosome, was found in about half of mitotic preparations. The existence of statistically significant karyotypic diversity was demonstrated through the application of orcein staining, C-banding and H-banding. This study represents the first discovery and characterization of horn fly karyotypes with 2n=11 (2n=10+B). All spermatocytes analyzed showed 5 chromosome bivalents, and therefore, 2n=10 without an extra chromosome. Study of mitotic divisions showed that some chromosomal rearrangements affecting karyotype structure are maintained as polymorphisms, and multiple correspondence analyses demonstrated that genetic variation was not associated with geographic distribution. Because it was never observed during male meiosis, we hypothesize that B-chromosome is preferentially transmitted by females and that it might be related to sex determination. PMID:25893073

  9. Extraction of trace metals from fly ash

    DOEpatents

    Blander, M.; Wai, C.M.; Nagy, Z.

    1983-08-15

    A process is described for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous. The fly ash has a silicate base and contains surface deposits of the trace metals as oxides, chlorides or the like. The process is carried out by contacting the fly ash with AlCl/sub 3/ in an alkali halide melt to react the trace metals with the AlCl/sub 3/ to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.

  10. Size dependent cytotoxicity of fly ash particles

    SciTech Connect

    Liu, W.K.; Tam, J.S.K.; Wong, M.H.

    1988-01-01

    Fly ash samples were collected from the electrostatic precipitator of a coal-fired power plant in Hong Kong. The particles of the respirable range (smaller than 10 {mu}m) were divided into 4 groups according to their particle size (mass median aerodynamic diameters). The surface morphology and the metal contents (Fe, Mn, Al and Zn) of fly ash particles were examined by a scanning electron microscopy and an inductively coupled plasma spectrophotometer, respectively. The particles were very heterogeneous in size and shape as well as the concentration of metals. The cytotoxicity of these four groups of fly ash particles were evaluated using an in vitro rat alveolar macrophages culture assay. The viability of alveolar macrophages was lower when incubated with smaller size particles. This relationship was also reflected by the damage of the surface morphology of the cells and the release of cytoplasmic (lactate dehydrogenase) and lysosomal (acid phosphatase and {beta}-glucuronidase) marker enzymes into the culture media.

  11. Pigments of fly agaric (Amanita muscaria).

    PubMed

    Stintzing, Florian; Schliemann, Willibald

    2007-01-01

    The complex pigment pattern of fly agaric (Amanita muscaria) cap skins has been studied by LC-DAD and mass spectrometry. Among the betaxanthins the corresponding derivatives of serine, threonine, ethanolamine, alanine, Dopa, phenylalanine and tryptophan are reported for the first time to contribute to the pigment pattern of fly agarics. Betalamic acid, the chromophoric precursor of betaxanthins and betacyanins, muscaflavin and seco-dopas were also detected. Furthermore, the red-purple muscapurpurin and the red muscarubrin were tentatively assigned while further six betacyanin-like components could not be structurally allocated. Stability studies indicated a high susceptibility of pigment extracts to degradation which led to rapid colour loss thus rendering a complete characterization of betacyanin-like compounds impossible at present. Taking into account these difficulties the presented results may be a starting point for a comprehensive characterization of the pigment composition of fly agarics. PMID:18274277

  12. Extraction of trace metals from fly ash

    DOEpatents

    Blander, Milton; Wai, Chien M.; Nagy, Zoltan

    1984-01-01

    A process for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous, the fly ash having a silicate base and containing surface deposits of the trace metals as oxides, chlorides or the like, with the process being carried out by contacting the fly ash with AlCl.sub.3 in an alkali halide melt to react the trace metals with the AlCl.sub.3 to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.

  13. Transient ischemic attack as a medical emergency.

    PubMed

    Okada, Yasushi

    2014-01-01

    Since transient ischemic attack (TIA) is regarded as a medical emergency with high risk for early stroke recurrence, the underlying mechanisms should be immediately clarified to conclude a definitive diagnosis and provide early treatment. Early risk stratification using ABCD(2) scores can predict the risk of ischemic stroke occurring after TIA. Carotid ultrasonography (US) can evaluate the degree of stenosis, plaque properties and flow velocity of ICA lesions. High-risk mobile plaques can be classified by carotid US, and aortogenic sources of emboli can be detected by transesophageal echocardiography. Cardiac monitoring and blood findings are thought to play a key role in a diagnosis of cardioembolic TIA. Diffusion-weighted imaging (DWI)-MRI and MR angiography are also indispensable to understand the mechanism of TIA and cerebral circulation. To prevent subsequent stroke arising from TIA, antiplatelet and anticoagulant therapies should be started immediately along with comprehensive management of life-style, hypertension, diabetes mellitus, dyslipidemia and other atherosclerotic diseases. Carotid endarterectomy and endovascular intervention are critical for treating symptomatic patients with significant stenosis of ICA. A novel concept of acute cerebrovascular syndrome (ACVS) has recently been advocated to increase awareness of TIA among citizens, patients and medical professionals. TIA should be recognized as the last opportunity to avoid irreversible ischemic stroke and its sequelae. The clinical relevance of the new concept of ACVS is advocated by early recurrence after TIA, analysis of high-risk TIA, treatment strategies and the optimal management of TIA. Raising TIA awareness should also proceed across many population sectors. PMID:24157554

  14. Presentation attack detection for face recognition using light field camera.

    PubMed

    Raghavendra, R; Raja, Kiran B; Busch, Christoph

    2015-03-01

    The vulnerability of face recognition systems isa growing concern that has drawn the interest from both academic and research communities. Despite the availability of a broad range of face presentation attack detection (PAD)(or countermeasure or antispoofing) schemes, there exists no superior PAD technique due to evolution of sophisticated presentation attacks (or spoof attacks). In this paper, we present a new perspective for face presentation attack detection by introducing light field camera (LFC). Since the use of a LFC can record the direction of each incoming ray in addition to the intensity, it exhibits an unique characteristic of rendering multiple depth(or focus) images in a single capture. Thus, we present a novel approach that involves exploring the variation of the focus between multiple depth (or focus) images rendered by the LFC that in turn can be used to reveal the presentation attacks. To this extent, we first collect a new face artefact database using LFC that comprises of 80 subjects. Face artefacts are generated by simulating two widely used attacks, such as photo print and electronic screen attack. Extensive experiments carried out on the light field face artefact database have revealed the outstanding performance of the proposed PAD scheme when benchmarked with various well established state-of-the-art schemes. PMID:25622320

  15. Possible precipitation of migraine attacks with prophylactic treatment.

    PubMed

    Donnet, A; Vuillaume De Diego, E; Lanteri-Minet, M

    2009-01-01

    The initiation of a prophylactic treatment in a migraine sufferer depends upon the stratification of the patient's frequency of attacks and the disability they cause, as well as the patient's acute consumption and comorbid diseases. We report on 14 patients who were among a group of 618 migraine sufferers who received a new preventative treatment. These 14 patients developed an increase in the frequency of their migraine attacks that was possibly induced by this new prophylactic treatment. The clinical description of the migraine attacks remained the same but the frequency of the attacks of migraine without aura was dramatically increased. This is, to our knowledge, the first description of a possible precipitation of attacks of migraine without aura with a prophylactic treatment. There is no link with a specific class of prophylactic treatment. We hypothesize that the migraine sufferers who experienced aggravation after the new prophylactic drug had been introduced had a paradoxical decrease in the induction threshold for cortical spreading depression (CSD). Mechanisms of such a decrease are unknown and are probably multifactorial, but changes in serotonin neurotransmission have been experimentally demonstrated to modify cortical excitability and favour CSD. The aggravation was described only for attacks without aura. However, with only 14 patients, it is not possible to predict whether suffering from that the type of migraine is a factor that predisposes a patient to aggravation. While additional cases are necessary, physicians should be aware of the possibility that prophylactic treatment may exacerbate migraine attacks. PMID:18948696

  16. Preventing sexual attacks in healthcare facilities: risk management considerations.

    PubMed

    Banja, John D

    2014-01-01

    Reports or allegations of sexual attacks in healthcare facilities are extremely upsetting and sometimes not given the attention they deserve. In June 2011, the United States Government Accountability Office (GAO) issued a remarkable report on sexual attacks occurring in Veterans Affairs (VA) health facilities that not only raised awareness of the magnitude of the problem but that detailed numerous system weaknesses in VA facilities that might have enabled such attacks. This article discusses some of the GAO's findings as well as other instances of sexual attacks, such as occurred in the criminal prosecution of Paul Serdula, a former health professional who might have sexually assaulted hundreds of women. Some of Serdula's victims have subsequently sued in civil court, charging Serdula's employers with lack of supervision and raising the possibility of serial sexual attacks such as his evolving into large-scale patient safety disasters. This article will review certain ethical and legal considerations bearing on the liability of healthcare facilities in which sexual attacks are alleged to have occurred. Following a discussion of how two courts have used the legal construct of "foreseeability" in determining a healthcare facility's liability when an employee is charged with sexual assault, the article will conclude with a host of patient safety recommendations aimed at discouraging or deterring the occurrence of sexual attacks. PMID:24549696

  17. Optimal response to attacks on the open science grids.

    SciTech Connect

    Altunay, M.; Leyffer, S.; Linderoth, J. T.; Xie, Z.

    2011-01-01

    Cybersecurity is a growing concern, especially in open grids, where attack propagation is easy because of prevalent collaborations among thousands of users and hundreds of institutions. The collaboration rules that typically govern large science experiments as well as social networks of scientists span across the institutional security boundaries. A common concern is that the increased openness may allow malicious attackers to spread more readily around the grid. We consider how to optimally respond to attacks in open grid environments. To show how and why attacks spread more readily around the grid, we first discuss how collaborations manifest themselves in the grids and form the collaboration network graph, and how this collaboration network graph affects the security threat levels of grid participants. We present two mixed-integer program (MIP) models to find the optimal response to attacks in open grid environments, and also calculate the threat level associated with each grid participant. Given an attack scenario, our optimal response model aims to minimize the threat levels at unaffected participants while maximizing the uninterrupted scientific production (continuing collaborations). By adopting some of the collaboration rules (e.g., suspending a collaboration or shutting down a site), the model finds optimal response to subvert an attack scenario.

  18. Risk factors for hypertensive attack during pheochromocytoma resection

    PubMed Central

    Kwon, Se Yun; Lee, Kyung Seop; Lee, Jun Nyung; Ha, Yun-Sok; Choi, Seock Hwan; Kim, Hyun Tae; Kim, Tae-Hwan; Yoo, Eun Sang

    2016-01-01

    Purpose We aimed to retrospectively evaluate the risk factors for hypertensive attack during adrenalectomy in patients with pheochromocytoma. Despite the development of newer surgical and anesthetic techniques for the management of pheochromocytoma, intraoperative hypertensive attack continues to present a challenge. Materials and Methods Data from 53 patients diagnosed with pheochromocytoma at Kyungpook National Uriversity Medical Center between January 2000 and June 2012 were retrospectively analyzed. The subjects were divided into 2 groups depending on the presence or absence of hypertensive attack at the time of surgery. Patient demographic characteristics and preoperative evaluations were assessed for their prognostic relevance with respect to hypertensive attack. A univariate analysis was conducted, and a multivariate logistic regression analysis was also performed. Results In the univariate analysis, systolic blood pressure at presentation, preoperative hormonal status (including epinephrine, norepinephrine, vanillylmandelic acid, and metanephrine levels in a 24-hour urine sample), tumor size, and postoperative systolic blood pressure were significantly associated with the development of hypertensive attack. In the multivariate analysis, preoperative epinephrine level and tumor size were independent factors that predicted hypertensive attack. The highest odds ratio for tumor size (2.169) was obtained at a cutoff value of 4.25 cm and the highest odds ratio for preoperative epinephrine (1.020) was obtained at a cutoff value of 166.3 µg/d. Conclusions In this study, a large tumor size and an elevated preoperative urinary epinephrine level were risk factors for intraoperative hypertensive attack in patients with pheochromocytoma. PMID:27194549

  19. The Hungry Fly: Hydrodynamics of feeding in the common house fly

    NASA Astrophysics Data System (ADS)

    Prakash, Manu; Steele, Miles

    2010-11-01

    A large number of insect species feed primarily on a fluid diet. To do so, they must overcome the numerous challenges that arise in the design of high-efficiency, miniature pumps. Although the morphology of insect feeding structures has been described for decades, their dynamics remain largely unknown even in the most well studied species (e.g. fruit fly). Here, we use invivo imaging and microsurgery to elucidate the design principles of feeding structures of the common house fly. Using high-resolution X-ray microscopy, we record invivo flow of sucrose solutions through the body over many hours during fly feeding. Borrowing from microsurgery techniques common in neurophysiology, we are able to perturb the pump to a stall position and thus evaluate function under load conditions. Furthermore, fluid viscosity-dependent feedback is observed for optimal pump performance. As the gut of the fly starts to fill up, feedback from the stretch receptors in the cuticle dictates the effective flow rate. Finally, via comparative analysis between the house fly, blow fly, fruit fly and bumble bees, we highlight the common design principles and the role of interfacial phenomena in feeding.

  20. A Novel Method for Tracking Individuals of Fruit Fly Swarms Flying in a Laboratory Flight Arena

    PubMed Central

    Cheng, Xi En; Qian, Zhi-Ming; Wang, Shuo Hong; Jiang, Nan; Guo, Aike; Chen, Yan Qiu

    2015-01-01

    The growing interest in studying social behaviours of swarming fruit flies, Drosophila melanogaster, has heightened the need for developing tools that provide quantitative motion data. To achieve such a goal, multi-camera three-dimensional tracking technology is the key experimental gateway. We have developed a novel tracking system for tracking hundreds of fruit flies flying in a confined cubic flight arena. In addition to the proposed tracking algorithm, this work offers additional contributions in three aspects: body detection, orientation estimation, and data validation. To demonstrate the opportunities that the proposed system offers for generating high-throughput quantitative motion data, we conducted experiments on five experimental configurations. We also performed quantitative analysis on the kinematics and the spatial structure and the motion patterns of fruit fly swarms. We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases. Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance. Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment. PMID:26083385

  1. Associational resistance, gall-fly preferences, and a stem dimorphism in Solidago altissima

    NASA Astrophysics Data System (ADS)

    Wise, Michael J.; Yi, Ceal G.; Abrahamson, Warren G.

    2009-05-01

    In most populations of Solidago altissima, a small proportion of plants have a growth pattern in which the stem bends early in the season so that the apex is pointing downward (i.e., a "candy-cane" stem) then straightens up again later in the season. The majority of plants, however, do not show this pattern. Instead their stems remain erect from emergence through flowering and senescence. It has recently been shown that the candy-cane stems are a result of a ducking strategy that reduces the risk of attack by apex-attacking herbivores. With such a resistance advantage, it is unclear why the candy-cane morphology is always in the minority, and why the erect morphology persists at all in S. altissima populations. In this study, we tested the hypothesis that the advantage of ducking is inversely frequency dependent and thus will not be an effective resistance strategy when ducking plants are in the majority. In a series of trials, we introduced gall flies ( Eurosta solidaginis) into enclosures with relatively low (15%) and relatively high (85%) frequencies of candy-cane versus erect stems. Candy-cane stems were more resistant than erect stems regardless of relative frequency; thus, the hypothesis was rejected. Overall, attack rates were lower for both stem types in the high candy-cane frequency groups than in the low candy-cane frequency groups. This frequency-dependent attack rate suggests that erect-stemmed plants gain "associational resistance" by having a majority of candy-cane neighbors, while candy-cane plants suffer from "associational susceptibility" when surrounded by erect-stemmed neighbors.

  2. TCPL: A Defense against wormhole attacks in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Kumar, K. E. Naresh; Waheed, Mohd. Abdul; Basappa, K. Kari

    2010-10-01

    Do In this paper presents recent advances in technology have made low-cost, low-power wireless sensors with efficient energy consumption. A network of such nodes can coordinate among themselves for distributed sensing and processing of certain data. For which, we propose an architecture to provide a stateless solution in sensor networks for efficient routing in wireless sensor networks. This type of architecture is known as Tree Cast. We propose a unique method of address allocation, building up multiple disjoint trees which are geographically inter-twined and rooted at the data sink. Using these trees, routing messages to and from the sink node without maintaining any routing state in the sensor nodes is possible. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many sensor network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a new, general mechanism, called packet leashes, for detecting and thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes.

  3. TCPL: A Defense against wormhole attacks in wireless sensor networks

    SciTech Connect

    Kumar, K. E. Naresh; Waheed, Mohd. Abdul; Basappa, K. Kari

    2010-10-26

    Do In this paper presents recent advances in technology have made low-cost, low-power wireless sensors with efficient energy consumption. A network of such nodes can coordinate among themselves for distributed sensing and processing of certain data. For which, we propose an architecture to provide a stateless solution in sensor networks for efficient routing in wireless sensor networks. This type of architecture is known as Tree Cast. We propose a unique method of address allocation, building up multiple disjoint trees which are geographically inter-twined and rooted at the data sink. Using these trees, routing messages to and from the sink node without maintaining any routing state in the sensor nodes is possible. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many sensor network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a new, general mechanism, called packet leashes, for detecting and thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes.

  4. Smoking Behavior and Alcohol Consumption in Individuals With Panic Attacks

    PubMed Central

    Mathew, Amanda R.; Norton, Peter J.; Zvolensky, Michael J.; Buckner, Julia D.; Smits, Jasper A. J.

    2011-01-01

    Individuals with anxiety often report greater smoking and drinking behaviors relative to those without a history of anxiety. In particular, smoking and alcohol use have been directly implicated among individuals experiencing panic attacks, diagnosed with panic disorder, or high on panic-relevant risk factors such as anxiety sensitivity. Less is known, however, about specific features of panic that may differentiate among those who do or do not use cigarettes or alcohol. The purpose of the current study was to replicate previous research findings of an association between panic symptomatology, cigarette smoking, and alcohol consumption, as well as extend findings by examining whether specific symptoms of panic attacks differentiated among those who do or do not use cigarettes or alcohol. Participants (n = 489) completed the Panic Attack Questionnaire-IV, a highly detailed assessment of panic attacks and symptoms, as well as self-report measures of smoking history and alcohol use. Consistent with previous research, participants who reported a history of panic attacks (n = 107) were significantly more likely to report current daily or lifetime daily cigarette smoking, and significantly greater hazardous or harmful alcohol use than participants with no panic history (n = 382). Although smoking and hazardous alcohol use were highly associated regardless of panic status, participants with panic attacks showed elevated hazardous alcohol use after controlling for daily or lifetime smoking. Surprisingly, although participants who reported having had at least one panic attack were more likely to smoke, panic attack symptoms, intensity, or frequency did not differentiate panickers who did or did not smoke. Furthermore, panic-related variables were not shown to differentially relate to problematic drinking among panickers. Implications for understanding the complex relationship between panic attacks and smoking and drinking behaviors are discussed. PMID:21915160

  5. 9/11, Act II: a fine-grained analysis of regional variations in traffic fatalities in the aftermath of the terrorist attacks.

    PubMed

    Gaissmaier, Wolfgang; Gigerenzer, Gerd

    2012-12-01

    Terrorists can strike twice--first, by directly killing people, and second, through dangerous behaviors induced by fear in people's minds. Previous research identified a substantial increase in U.S. traffic fatalities subsequent to the September 11 terrorist attacks, which were accounted for as due to a substitution of driving for flying, induced by fear of dread risks. Here, we show that this increase in fatalities varied widely by region, a fact that was best explained by regional variations in increased driving. Two factors, in turn, explained these variations in increased driving. The weaker factor was proximity to New York City, where stress reactions to the attacks were previously shown to be greatest. The stronger factor was driving opportunity, which was operationalized both as number of highway miles and as number of car registrations per inhabitant. Thus, terrorists' second strike exploited both fear of dread risks and, paradoxically, an environmental structure conducive to generating increased driving, which ultimately increased fatalities. PMID:23160203

  6. A FLYING WIRE SYSTEM IN THE AGS.

    SciTech Connect

    HUANG,H.; BUXTON,W.; MAHLER,G.; MARUSIC,A.; ROSER,T.; SMITH,G.; SYPHERS,M.; WILLIAMS,N.; WITKOVER,R.

    1999-03-29

    As the AGS prepares to serve as the injector for RHIC, monitoring and control of the beam transverse emittance become a major and important topic. Before the installation of the flying wire system, the emittance was measured with ionization profile monitors in the AGS, which require correction for space charge effects. It is desirable to have a second means of measuring profile that is less depend on intensity. A flying wire system has been installed in the AGS recently to perform this task. This paper discusses the hardware and software setup and the capabilities of the system.

  7. How mosquitoes fly in the rain

    NASA Astrophysics Data System (ADS)

    Dickerson, Andrew; Shankles, Peter; Madhavan, Nihar; Hu, David

    2011-11-01

    Mosquitoes thrive during rainfall and high humidity. If raindrops are 50 times heavier than mosquitoes, how do mosquitoes fly in the rain? In this combined experimental and theoretical study, we measure the impact force between a falling drop and a free-flying mosquito. High-speed videography of mosquitoes and custom-built mimics reveals a mosquito's low inertia renders it impervious to falling drops. Drops do not splash on mosquitoes, but simply push past them allowing a mosquito to continue on its flight path undeterred. We rationalize the force imparted using scaling relations based on the time of rebound between a falling drop and a free body of significantly less mass.

  8. Simulated flying performance after marihuana intoxication.

    PubMed

    Janowsky, D S; Meacham, M P; Blaine, J D; Schoor, M; Bozzetti, L P

    1976-02-01

    Ten pilots smoked, in counterbalanced order on a double blind basis, a social dose of marihuana (.09 mg/kg delta-9-tetrahydrocannabinol) and a matched placebo after being trained to fly a specific flight sequence on an ATC-510 flight simulator. In contrast to placebo, marihuana caused a gross decrement in flying performance, with increased prevalence of major errors, minor errors, altitude deviations, heading deviations, and radio navigation errors. These effects of active marihuana persisted for at least 2 hr and generally had disappeared by 4 to 6 hr after marihuana administration. PMID:1252201

  9. Using fly ash to mitigate explosions

    SciTech Connect

    Taulbee, D.

    2008-07-01

    In 2005 the University of Kentucky's Center for Applied Energy Research was given funding to evaluate the use of coal combustion by-products (CCBs) to reduce the explosive potential of ammonium nitrate (AN) fertilizers. Fly ash C (FAC), fly ash F (FAF) and flue gas desulfurization by-product (FGD) were evaluated. It was found that applying a CCB coating to the AN particles at concentrations of 5 wt% or greater prevented the AN explosion from propagating. The article reports on results so far and outlines further work to be done. 6 figs.

  10. Benchmark Problems for Space Mission Formation Flying

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Leitner, Jesse A.; Folta, David C.; Burns, Richard

    2003-01-01

    To provide a high-level focus to distributed space system flight dynamics and control research, several benchmark problems are suggested for space mission formation flying. The problems cover formation flying in low altitude, near-circular Earth orbit, high altitude, highly elliptical Earth orbits, and large amplitude lissajous trajectories about co-linear libration points of the Sun-Earth/Moon system. These problems are not specific to any current or proposed mission, but instead are intended to capture high-level features that would be generic to many similar missions that are of interest to various agencies.

  11. Fly Ash Characteristics and Carbon Sequestration Potential

    SciTech Connect

    Palumbo, Anthony V.; Amonette, James E.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Daniels, William L.

    2007-07-20

    Concerns for the effects of global warming have lead to an interest in the potential for inexpensive methods to sequester carbon dioxide (CO2). One of the proposed methods is the sequestration of carbon in soil though the growth of crops or forests.4,6 If there is an economic value placed on sequestration of carbon dioxide in soil there may be an an opportunity and funding to utilize fly ash in the reclamation of mine soils and other degraded lands. However, concerns associated with the use of fly ash must be addressed before this practice can be widely adopted. There is a vast extent of degraded lands across the world that has some degree of potential for use in carbon sequestration. Degraded lands comprise nearly 2 X 109 ha of land throughout the world.7 Although the potential is obviously smaller in the United States, there are still approximately 4 X 106 ha of degraded lands that previously resulted from mining operations14 and an additional 1.4 X 108 ha of poorly managed lands. Thus, according to Lal and others the potential is to sequester approximately 11 Pg of carbon over the next 50 years.1,10 The realization of this potential will likely be dependent on economic incentives and the use of soil amendments such as fly ash. There are many potential benefits documented for the use of fly ash as a soil amendment. For example, fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, HCO3-, Cl- and basic cations, although some effects are notably decreased in high-clay soils.8,13,9 The potential is that these effects will promote increased growth of plants (either trees or grasses) and result in greater carbon accumulation in the soil than in untreated degraded soils. This paper addresses the potential for carbon sequestration in soils amended with fly ash and examines some of the issues that should be considered in planning this option. We describe retrospective studies of soil carbon accumulation on

  12. Changeing of fly ash leachability after grinding

    NASA Astrophysics Data System (ADS)

    Lakatos, J.; Szabo, R.; Racz, A.; Banhidi, O.; Mucsi, G.

    2016-04-01

    Effect of grinding on the reactivity of fly ash used for geopolymer production was tested. Extraction technique using different alkaline and acidic solutions were used for detect the change of the solubility of elements due to the physical and mechano-chemical transformation of minerals in function of grinding time. Both the extraction with alkaline and acidic solution have detected improvement in solubility in function of grinding time. The enhancement in alkaline solution was approx. 100% in case of Si and Al. The acidic medium able to dissolve the fly ash higher manner than the alkaline, therefore the effect of grinding was found less pronounced.

  13. The secret lives of Drosophila flies.

    PubMed

    Markow, Therese Ann

    2015-01-01

    Flies of the genus Drosophila, and particularly those of the species Drosophila melanogaster, are best known as laboratory organisms. As with all model organisms, they were domesticated for empirical studies, but they also continue to exist as wild populations. Decades of research on these flies in the laboratory have produced astounding and important insights into basic biological processes, but we have only scratched the surface of what they have to offer as research organisms. An outstanding challenge now is to build on this knowledge and explore how natural history has shaped D. melanogaster in order to advance our understanding of biology more generally. PMID:26041333

  14. Towards A Taxonomy Of Attacks Against Energy Control Systems

    NASA Astrophysics Data System (ADS)

    Fleury, Terry; Khurana, Himanshu; Welch, Von

    Control systems in the energy sector (e.g., supervisory control and data acquisition (SCADA) systems) involve a hierarchy of sensing, monitoring and control devices connected to centralized control stations or centers. The incorporation of commercial off-the-shelf technologies in energy control systems makes them vulnerable to cyber attacks. A taxonomy of cyber attacks against control systems can assist the energy sector in managing the cyber threat. This paper takes the first step towards a taxonomy by presenting a comprehensive model of attacks, vulnerabilities and damage related to control systems. The model is populated based on a survey of the technical literature from industry, academia and national laboratories.

  15. A Cyber-Attack Detection Model Based on Multivariate Analyses

    NASA Astrophysics Data System (ADS)

    Sakai, Yuto; Rinsaka, Koichiro; Dohi, Tadashi

    In the present paper, we propose a novel cyber-attack detection model based on two multivariate-analysis methods to the audit data observed on a host machine. The statistical techniques used here are the well-known Hayashi's quantification method IV and cluster analysis method. We quantify the observed qualitative audit event sequence via the quantification method IV, and collect similar audit event sequence in the same groups based on the cluster analysis. It is shown in simulation experiments that our model can improve the cyber-attack detection accuracy in some realistic cases where both normal and attack activities are intermingled.

  16. Pulmonary response to cadmium and nickel coated fly ash

    SciTech Connect

    Bajpai, R.; Waseem, M.; Kaw, J.L.

    1994-12-31

    Pulmonary reaction to fly ash coated with cadmium (Cd) or nickel (Ni) and to native fly ash was studied in rats after intratracheal inoculation of dust suspensions. The histopathological alterations and changes in biochemical and cellular constituents of the bronchoalveolar lavage were correlated with the metal content in lungs and kidneys. More Ni was adsorbed than Cd on fly ash particulates. Metal-coated fly ash was more toxic than uncoated fly ash. Cd-coated fly ash produced significantly more histopathological and biochemical changes than Ni-coated fly ash. A high concentration of Cd was detected in the kidneys of rats exposed to Cd-coated fly ash. 32 refs., 7 figs., 2 tabs.

  17. Eco-friendly fly ash utilization: potential for land application

    SciTech Connect

    Malik, A.; Thapliyal, A.

    2009-07-01

    The increase in demand for power in domestic, agricultural, and industrial sectors has increased the pressure on coal combustion and aggravated the problem of fly ash generation/disposal. Consequently the research targeting effective utilization of fly ash has also gained momentum. Fly ash has proved to be an economical substitute for expensive adsorbents as well as a suitable raw material for brick manufacturing, zeolite synthesis, etc. Fly ash is a reservoir of essential minerals but is deficient in nitrogen and phosphorus. By amending fly ash with soil and/or various organic materials (sewage sludge, bioprocess materials) as well as microbial inoculants like mycorrhizae, enhanced plant growth can be realized. Based on the sound results of large scale studies, fly ash utilization has grown into prominent discipline supported by various internationally renowned organizations. This paper reviews attempts directed toward various utilization of fly ash, with an emphasis on land application of organic/microbial inoculants amended fly ash.

  18. Wind generated by an attacking bat: anemometric measurements and detection by the praying mantis cercal system.

    PubMed

    Triblehorn, Jeffrey D; Yager, David D

    2006-04-01

    The wind-sensitive cercal system, well-known for mediating terrestrial escape responses, may also mediate insect aerial bat-avoidance responses triggered by wind generated by the approaching bat. One crucial question is whether enough time exists between detection and capture for the insect to perform a successful evasive maneuver. A previous study estimated this time to be 16 ms, based on cockroach behavioral latencies and a prediction for the detection time derived from a simulated predator moving toward a simulated prey. However, the detection time may be underestimated since both the simulated predator and prey lacked certain characteristics present in the natural situation. In the present study, actual detection times are measured by recording from wind-sensitive interneurons of a tethered praying mantis that serves as the target for a flying, attacking bat. Furthermore, using hot-wire anemometry, we describe and quantify the wind generated by an attacking bat. Anemometer measurements revealed that the velocity of the bat-generated wind consistently peaks early with a high acceleration component (an important parameter for triggering wind-mediated terrestrial responses). The physiological recordings determined that the mantis cercal system detected an approaching bat 74 ms before contact, which would provide the insect with 36 ms to perform a maneuver before capture. This should be sufficient time for the mantis to respond. Although it probably would not have time for a full response that completely evades the bat, even a partial response might alter the mantid's trajectory enough to cause the bat to mishandle the insect, allowing it to escape. PMID:16574803

  19. Studies on the flight patterns of foraging sand flies.

    PubMed

    Faiman, R; Kirstein, O; Moncaz, A; Guetta, H; Warburg, A

    2011-01-01

    Phlebotomine sand flies transmit Leishmania parasites that cause leishmaniasis in humans. We report experimental results that improve our understanding of how foraging sand flies proceed over flat or sloping ground and how they negotiate vertical obstacles. Three rows of traps were suspended at different heights on a wire fence. Those just above ground level captured 87% of all flies, traps set at one meter captured 11% while only 2% of the flies were captured in traps set two meters above ground. When traps were deployed on a vertical support wall, the mean catch per trap was much higher than for traps suspended on the fence. Traps suspended just above ground level captured 57% of all flies, traps set at one meter above ground captured 27% of the flies and even traps set at two meters captured 16% of the flies. Although, most flies were still captured close to the ground, a higher percentage reached the second and third rows of traps. Sticky traps on a vertical wall produced similar results with significantly more flies alighting on the lower sections of the trap closest to the ground. On a vertical sand fly-proof net the overall dispersal of the flies was more like on a wall than in open space. Traps suspended just above ground level captured 49%, traps set at one meter above ground captured 36% and traps set at two meters captured 15% of the flies. Following spraying of the net with deltamethrin (1%), fewer sand flies were captured but the reduction was not statistically significant. Our conclusions are that being small and frail, sand flies tend to fly close to the ground probably in order to avoid being swept away by gusts of wind. When they encounter a vertical obstacle, they proceed upwards close to the obstacle with intermittent stops. Therefore, insecticide-sprayed walls or vertical nets should be effective for controlling sand flies approaching human habitation. PMID:21756865

  20. After-gate attack on a quantum cryptosystem

    NASA Astrophysics Data System (ADS)

    Wiechers, C.; Lydersen, L.; Wittmann, C.; Elser, D.; Skaar, J.; Marquardt, Ch; Makarov, V.; Leuchs, G.

    2011-01-01

    We present a method to control the detection events in quantum key distribution systems that use gated single-photon detectors. We employ bright pulses as faked states, timed to arrive at the avalanche photodiodes outside the activation time. The attack can remain unnoticed, since the faked states do not increase the error rate per se. This allows for an intercept-resend attack, where an eavesdropper transfers her detection events to the legitimate receiver without causing any errors. As a side effect, afterpulses, originating from accumulated charge carriers in the detectors, increase the error rate. We have experimentally tested detectors of the system id3110 (Clavis2) from ID Quantique. We identify the parameter regime in which the attack is feasible despite the side effect. Furthermore, we outline how simple modifications in the implementation can make the device immune to this attack.