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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. 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.

  3. 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.

  4. Hessian fly (Mayetiola destructor) attack causes a dramatic shift in carbon and nitrogen metabolism in wheat.

    PubMed

    Zhu, Lieceng; Liu, Xuming; Liu, Xiang; Jeannotte, Richard; Reese, John C; Harris, Marion; Stuart, Jeffrey J; Chen, Ming-Shun

    2008-01-01

    Carbon and nitrogen (C/N) metabolism and allocation within the plant have important implications for plant-parasite interactions. Many plant parasites manipulate the host by inducing C/N changes that benefit their own survival and growth. Plant resistance can prevent this parasite manipulation. We used the wheat-Hessian fly (Mayetiola destructor) system to analyze C/N changes in plants during compatible and incompatible interactions. The Hessian fly is an insect but shares many features with plant pathogens, being sessile during feeding stages and having avirulence (Avr) genes that match plant resistance genes in gene-for-gene relationships. Many wheat genes involved in C/N metabolism were differentially regulated in plants during compatible and incompatible interactions. In plants during compatible interactions, the content of free carbon-containing compounds decreased 36%, whereas the content of free nitrogen-containing compounds increased 46%. This C/N shift was likely achieved through a coordinated regulation of genes in a number of central metabolic pathways, including glycolysis, the tricarboxylic acid cycle, and amino-acid synthesis. Our data on plants during compatible interactions support recent findings that Hessian fly larvae create nutritive cells at feeding (attack) sites and manipulate host plants to enhance their own survival and growth. In plants during incompatible interactions, most of the metabolic genes examined were not affected or down-regulated.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. Experimental Modeling of the Formation of Saucer-Shaped sills

    NASA Astrophysics Data System (ADS)

    Galland, O.; Planke, S.; Malthe-Sorenssen, A.

    2007-12-01

    Many magma intrusions in sedimentary basins are sills, and especially saucer-shaped sills. These features are observed in many places (i.e. South Africa; the Norwegian and North Sea; Siberia; Argentina). Sand injectites exhibit similar geometries. The occurrence of such features in so various settings suggests that their emplacement results from fundamental processes in sedimentary basins. To understand such processes, we performed experimental modeling of saucer-shaped sill emplacement. The experiments consist of injecting a molten low viscosity vegetable oil (model magma) at a constant flow rate into a fine-grained Coulomb silica flour (model rock). When the oil starts intruding, the initially flat surface of the model inflates and forms a smooth dome. At the end of the experiment, the oil erupts at the edge of the dome. After the experiment, the oil cools and solidifies, the resulting solid intrusion is unburied and exposed, and its upper surface digitalized. For our purpose, we did our experiments without external deformation. We performed two series of experiments with varying depth of injection. The first series consisted of injection into a homogeneous medium. The resulting intrusions were cone-sheets and dykes. The second series consisted of heterogeneous models where the heterogeneity was a weak layer made of a flexible net. The resulting intrusions were made of (1) a horizontal basal sill emplaced along the weakness, and (2) inclined sheets nucleating at the edges of the basal sill and propagating upward and outward. The inclined sheets exhibited a convex shape, i.e. a decreasing slope outward. In addition, the deeper the sills emplaced, the larger they were. Our experimental results are consistent with saucer-shaped features in nature. We infer from our results that the transition between the basal sills and the inclined sheets results from a transition of emplacement processes. We suggest that the basal sill emplace by open (mode I) fracturing, whereas

  11. 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.

  12. 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

  13. 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

  14. 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...

  15. 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

  16. 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

  17. Symptomatic Bilateral Torn Discoid Medial Meniscus Treated with Saucerization and Suture

    PubMed Central

    2016-01-01

    Discoid meniscus is an anatomical congenital anomaly more often found in the lateral meniscus. A discoid medial meniscus is a very rare anomaly, and even more rare is to diagnose a bilateral discoid medial meniscus although the real prevalence of this situation is unknown because not all the discoid medial menisci are symptomatic and if the contralateral knee is not symptomatic then it is not usually studied. The standard treatment of this kind of pathology is partial meniscectomy. Currently the tendency is to be very conservative so suture and saucerization of a torn discoid meniscus when possible are gaining support. We present the case of a 13-year-old patient who was diagnosed with symptomatic torn bilateral discoid medial meniscus treated by suturing the tear and saucerization. To the best of our knowledge this is the first case reported of bilateral torn discoid medial meniscus treated in this manner in the same patient. PMID:27656305

  18. Symptomatic Bilateral Torn Discoid Medial Meniscus Treated with Saucerization and Suture

    PubMed Central

    2016-01-01

    Discoid meniscus is an anatomical congenital anomaly more often found in the lateral meniscus. A discoid medial meniscus is a very rare anomaly, and even more rare is to diagnose a bilateral discoid medial meniscus although the real prevalence of this situation is unknown because not all the discoid medial menisci are symptomatic and if the contralateral knee is not symptomatic then it is not usually studied. The standard treatment of this kind of pathology is partial meniscectomy. Currently the tendency is to be very conservative so suture and saucerization of a torn discoid meniscus when possible are gaining support. We present the case of a 13-year-old patient who was diagnosed with symptomatic torn bilateral discoid medial meniscus treated by suturing the tear and saucerization. To the best of our knowledge this is the first case reported of bilateral torn discoid medial meniscus treated in this manner in the same patient.

  19. 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.

  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

    ... 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 ...

  2. 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.

  3. 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.

  4. 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...

  5. 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 ...

  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. 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 ...

  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. 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.

  10. Shark attack.

    PubMed

    Guidera, K J; Ogden, J A; Highhouse, K; Pugh, L; Beatty, E

    1991-01-01

    Shark attacks are rare but devastating. This case had major injuries that included an open femoral fracture, massive hemorrhage, sciatic nerve laceration, and significant skin and muscle damage. The patient required 15 operative procedures, extensive physical therapy, and orthotic assistance. A review of the literature pertaining to shark bites is included.

  11. 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

  12. 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 ...

  13. 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.

  14. [Horse infestation with the larva of the deer warble fly, Hypoderma diana Brauer, 1985 (Diptera, Hypodermatidae)].

    PubMed

    Minár, J

    1987-03-01

    In South Bohemia a case was discovered of a yearling colt attacked by the larva of the IIIrd instar of the deer warble fly Hypoderma diana Brauer. The dead, almost mature larva of the fly was squeezed out of a subcutaneous lump above the shoulder in the first decade of April, 1985. The case is evaluated from the point of view of the possibility of the transition of specific parasites--warble flies--to another host. The attacking of a non-specific kind can occasionally occur only when there is a large number of the parasites and both kinds of host. At present the degree of attacking of deer by subcutaneous warble flies is high and therefore under favourable circumstances even domestic animals can be attacked by this type of warble fly. The above case is the first to be ascertained of a horse being attacked by a deer warble fly. PMID:3107199

  15. [Horse infestation with the larva of the deer warble fly, Hypoderma diana Brauer, 1985 (Diptera, Hypodermatidae)].

    PubMed

    Minár, J

    1987-03-01

    In South Bohemia a case was discovered of a yearling colt attacked by the larva of the IIIrd instar of the deer warble fly Hypoderma diana Brauer. The dead, almost mature larva of the fly was squeezed out of a subcutaneous lump above the shoulder in the first decade of April, 1985. The case is evaluated from the point of view of the possibility of the transition of specific parasites--warble flies--to another host. The attacking of a non-specific kind can occasionally occur only when there is a large number of the parasites and both kinds of host. At present the degree of attacking of deer by subcutaneous warble flies is high and therefore under favourable circumstances even domestic animals can be attacked by this type of warble fly. The above case is the first to be ascertained of a horse being attacked by a deer warble fly.

  16. 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!

  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. Flies in the face of adversity.

    PubMed

    Fellowes, M

    2001-04-01

    All organisms face attack from many natural enemies and all in turn have some means of defence. Can resistance evolve, and if it can, why doesn't it? Recent work on fruit flies and their parasitic wasps has shed light on these questions.

  19. 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.

  20. Formation of D- and I-shaped geochemical profiles in saucer-shaped sills due to post- emplacement magma flow induced by thermal stresses

    NASA Astrophysics Data System (ADS)

    Aarnes, I.; Podladchikov, Y. Y.; Neumann, E.

    2007-12-01

    There are still unresolved problems in the processes of emplacement and crystallization of saucer shaped sill intrusions. We use geochemistry and numerical modelling in order to constrain identify processes in mafic sill intrusions. Profiles sampled through through a saucer-shaped sill complex in the Karoo igneous province, South Africa show a variety of geochemical variations. Some variations are observed repeatedly, i.e. the D- and I-shaped profiles. D-shaped profiles are recognized by having the least evolved composition in the center (high Mg#) with more evolved composition at the upper and lower margins (low Mg#), resulting in a D-shaped Mg# profile. I- shaped profiles are recognized by having no variation in the Mg# through the profile. The formation mechanism of D-shaped profiles is enigmatic, as classical fractional crystallization theory predicts C-shapes to occur. The least evolved composition will be at the margins where crystallization initiates, and with continued cooling and crystallization the center will be progressively more evolved. Hence, we need another formation mechanism. The most common explanation for D-shaped profiles is a movement of early formed phenocrysts towards the center due to flow segregation. However, petrographical evidences from a D-shaped profile in this study show no phenocryst assemblage in the center, and the modal composition is homogeneous through the profile. We propose that differentiation is caused by a melt flow from the central parts of the sill towards the margins driven by underpressure anomalies at the margins. The underpressures develop because of strong cooling gradients at the margins, assuming no volume change due to a rigid crystal network. The less compatible elements associated with the melt phase will be transported into the margins by advection, resulting in a more evolved total system composition from a higher total melt percentage. The central parts will progressively be depleted in the less compatible

  1. Wild boar attacks.

    PubMed

    Gunduz, Abdulkadir; Turedi, Suleyman; Nuhoglu, Irfan; Kalkan, Asim; Turkmen, Suha

    2007-01-01

    Attacks on humans by wild boar (Sus scrofa) are occasionally reported in rural areas of Turkey. While fatalities are rare, individuals may sustain significant soft tissue trauma. Lower extremity lacerations of up to 10 cm in length and 4 cm deep were seen in the 3 cases reviewed. Injuries to the upper abdomen and chest occurred in one case. Attacks frequently occur in forested areas covered by dense brushwood, and their incidence is increased during the rutting season. In contrast to other large, feral animal attacks, injuries sustained from wild boar typically are limited to the lower extremities. This case series examines 3 attacks by wild boar in rural Turkey.

  2. Transient Ischemic Attack

    MedlinePlus

    Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only ... TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a ...

  3. Target-invariant aggressive display in a tephritid fly.

    PubMed

    Aguilar-Argüello, Samuel; Díaz-Fleischer, Francisco; Rao, Dinesh

    2015-12-01

    Fruit flies of the family Tephritidae (Diptera) use specialized wing displays in aggressive encounters with conspecifics and predators. These displays, called supination displays, have been thought to deter attacks from one of their main predators, spiders of the family Salticidae. However, there is no information whether the display is qualitatively or quantitatively different when the target is a conspecific or a predator. In this study, we sought to determine whether flies vary their displays depending on the display target. Using the Mexican fruit fly Anastrepha ludens, we compared the characteristics of the display that male and female flies use against conspecifics and spiders. Flies did not distinguish between spiders and conspecifics in terms of display rates and bout duration. In general, flies are more likely to retreat faster from spiders after performing a display. We suggest that supination is a generalized aggressive behavior that is independent of the target. PMID:26478252

  4. 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.

  5. 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

  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. A fatal leopard attack.

    PubMed

    Hejna, Petr

    2010-05-01

    A rare case of a big cat fatal attack is presented. A male leopard that had escaped from its unlocked cage attacked a 26-year-old male zoo worker. The man sustained penetrating injuries to the neck with consequent external bleeding. The man died while being transported to the hospital as a result of the injuries sustained. The wounds discovered on the victim's body corresponded with the known methods of leopard attacks and with findings on the carcasses of animals killed by leopards in the wild. The conclusion of the medicolegal investigation was that the underlying cause of death was a bite wound to the neck which lacerated the left internal jugular vein, the two main branches of the left external carotid artery, and the cervical spine. The cause of death was massive external bleeding. Special attention is paid to the general pattern of injuries sustained from big cat attacks.

  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. Cooperating attackers in neural cryptography.

    PubMed

    Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

    2004-06-01

    A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

  10. Estimating Orientation of Flying Fruit Flies.

    PubMed

    Cheng, Xi En; Wang, Shuo Hong; Qian, Zhi-Ming; Chen, Yan Qiu

    2015-01-01

    The recently growing interest in studying flight behaviours of fruit flies, Drosophila melanogaster, has highlighted the need for developing tools that acquire quantitative motion data. Despite recent advance of video tracking systems, acquiring a flying fly's orientation remains a challenge for these tools. In this paper, we present a novel method for estimating individual flying fly's orientation using image cues. Thanks to the line reconstruction algorithm in computer vision field, this work can thereby focus on the practical detail of implementation and evaluation of the orientation estimation algorithm. The orientation estimation algorithm can be incorporated into tracking algorithms. We rigorously evaluated the effectiveness and accuracy of the proposed algorithm by running experiments both on simulation data and on real-world data. This work complements methods for studying the fruit fly's flight behaviours in a three-dimensional environment.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Shark attack in Natal.

    PubMed

    White, J A

    1975-02-01

    The injuries in 5 cases of shark attack in Natal during 1973-74 are reviewed. Experience in shark attacks in South Africa during this period is discussed (1965-73), and the value of protecting heavily utilized beaches in Natal with nets is assessed. The surgical applications of elasmobranch research at the Oceanographic Research Institute (Durban) and at the Headquarters of the Natal Anti-Shark Measures Board (Umhlanga Rocks) are described. Modern trends in the training of surf life-guards, the provision of basic equipment for primary resuscitation of casualties on the beaches, and the policy of general and local care of these patients in Natal are discussed.

  16. 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 ...

  17. 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...

  18. 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.

  19. 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…

  20. 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.

  1. 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

  2. Larval defense against attack from parasitoid wasps requires nociceptive neurons.

    PubMed

    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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Estimating Orientation of Flying Fruit Flies

    PubMed Central

    Cheng, Xi En; Wang, Shuo Hong; Qian, Zhi-Ming; Chen, Yan Qiu

    2015-01-01

    The recently growing interest in studying flight behaviours of fruit flies, Drosophila melanogaster, has highlighted the need for developing tools that acquire quantitative motion data. Despite recent advance of video tracking systems, acquiring a flying fly’s orientation remains a challenge for these tools. In this paper, we present a novel method for estimating individual flying fly’s orientation using image cues. Thanks to the line reconstruction algorithm in computer vision field, this work can thereby focus on the practical detail of implementation and evaluation of the orientation estimation algorithm. The orientation estimation algorithm can be incorporated into tracking algorithms. We rigorously evaluated the effectiveness and accuracy of the proposed algorithm by running experiments both on simulation data and on real-world data. This work complements methods for studying the fruit fly’s flight behaviours in a three-dimensional environment. PMID:26173128

  10. 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)

  11. 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.

  12. 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.

  13. 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…

  14. 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.

  15. [The dream of flying].

    PubMed

    Goddemeier, Christof

    2005-01-01

    More than a 100 years ago the Wright brothers succeeded in performing the first motor flight in the history of mankind. But irrespective of its technical realisation man has always dealt with flying. So myths, rites and fairy-tales as well reflect the different ideas of flying as these conceptions come to light again and again in dreams and visions. Whether ascension, expression of desire and yearning or sexual metaphor -- the idea of flying seems to be a universal magic figure of thinking.

  16. The effect of irradiation and mass rearing on the anti-predator behaviour of the Mexican fruit fly, Anastrepha ludens (Diptera: Tephritidae).

    PubMed

    Rao, D; Aguilar-Argüello, S; Montoya, P; Díaz-Fleischer, F

    2014-04-01

    Fruit flies (Diptera: Tephritidae) are major pests worldwide. The sterile insect technique, where millions of flies are reared, sterilized by irradiation and then released, is one of the most successful and ecologically friendly methods of controlling populations of these pests. The mating behaviour of irradiated and non-irradiated flies has been compared in earlier studies, but there has been little attention paid to the anti-predator behaviour of mass-reared flies, especially with respect to wild flies. Tephritid flies perform a supination display to their jumping spider predators in order to deter attacks. In this study, we evaluated the possibility of using this display to determine the anti-predator capabilities of mass-reared irradiated, non-irradiated flies, and wild flies. We used an arena setup and observed bouts between jumping spiders (Phidippus audax Hentz) and male Mexican fruit flies (Anastrepha ludens Loew). We show that although all flies performed a supination display to their predator, wild flies were more likely to perform a display and were significantly more successful in avoiding attack than mass-reared flies. We suggest that this interaction can be used to develop a rapid realistic method of quality control in evaluating anti-predator abilities of mass-reared fruit flies. PMID:24345386

  17. Autonomous Martian flying rover

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A remotely programmable, autonomous flying rover is proposed to extensively survey the Martian surface environment. A Mach .3, solar powered, modified flying wing could cover roughly a 2000 mile range during Martian daylight hours. Multiple craft launched from an orbiting mother ship could provide near-global coverage. Each craft is envisioned to fly at about 1 km above the surface and measure atmospheric composition, pressure and temperature, map surface topography, and remotely penetrate the near subsurface looking for water (ice) and perhaps evidence of life. Data collected are relayed to Earth via the orbiting mother ship. Near surface guidance and control capability is an adaptation of current cruise missile technology. A solar powered aircraft designed to fly in the low temperature, low density, carbon dioxide Martian atmosphere near the surface appears feasible.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Genetic attack on neural cryptography.

    PubMed

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

    2006-03-01

    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.

  3. 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.

  4. 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.

  5. Understanding tsetse flies.

    PubMed

    Langley, P A

    1994-12-01

    The discovery that tsetse flies are the vectors of African trypanosomosis, causing sleeping sickness in man and nagana in cattle, occurred at the start of a rapidly expanding colonialism in sub-Saharan Africa. Hence, the first research on the fly was largely taxonomic, coupled with a painstaking ecological approach to determine the identities and distribution limits of the different species. This was followed by closer attention to the physiology of the fly, both from the academic standpoint as related to its survival and reproduction in the field, and from the standpoint of its vectorial capacity. There are still conflicting hypotheses concerning the maturation of trypanosomes within the fly. Increasing concern for the environment led to a ban in the developed nations on the use of DDT as an insecticide which had been used successfully for tsetse control in Africa. This was followed by a ban on the use of organochlorine insecticides in general, and no doubt the next restrictions will be on the use of organophosphates and upon synthetic pyrethroids which have already been banned in the UK for the control of houseflies. Fortunately, research on the role of olfactory and visual stimuli of the tsetse, in the location of potential hosts, led to an improvement in methods for monitoring fly populations by means of traps and targets upon which the flies alight. So successful are such devices that, when treated with an insecticide, they can be used to sustain an increase in natural mortality in fly populations to such an extent that these populations decline to manageable levels.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Resource distribution in multiple attacks with imperfect detection of the attack outcome.

    PubMed

    Levitin, Gregory; Hausken, Kjell

    2012-02-01

    This article extends the previous research of consecutive attacks strategy by assuming that an attacker observes the outcome of each attack imperfectly. With given probabilities it may wrongly identify a destroyed target as undestroyed, and wrongly identify an undestroyed target as destroyed. The outcome of each attack is determined by a contest success function that depends on the amount of resources allocated by the defender and the attacker to each attack. The article suggests a probabilistic model of the multiple attacks and analyzes how the target destruction probability and the attacker's relative resource expenditure are impacted by the two probabilities of incorrect observation, the attacker's and defender's resource ratio, the contest intensity, the number of attacks, and the resource distribution across attacks. We analyze how the attacker chooses the number of attacks, the attack stopping rule, and the optimal resource distribution across attacks to maximize its utility.

  7. 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.

  8. Duloxetine-related panic attacks.

    PubMed

    Sabljić, Vladimir; Rakun, Radmir; Ružić, Klementina; Grahovac, Tanja

    2011-03-01

    Side-effects arising on the grounds of antidepressant administration pose as a substantial obstacle hindering successful depressive disorder treatment. Side-effects, especially those severe or those manifested through dramatic clinical presentations such as panic attacks, make the treatment far more difficult and shake patients' trust in both the treatment and the treating physician. This case report deals with a patient experiencing a moderately severe depressive episode, who responded to duloxetine treatment administered in the initial dose of 30 mg per day with as many as three panic attacks in two days. Upon duloxetine withdrawal, these panic attacks ceased as well. The patient continued tianeptine and alprazolam treatment during which no significant side-effects had been seen, so that she gradually recovered. Some of the available literature sources have suggested the possibility of duloxetine administration to the end of generalised anxiety disorder and panic attack treatment. However, they are outnumbered by the contributions reporting about duloxetine-related anxiety, aggressiveness and panic attacks. In line with the foregoing, further monitoring of each and every duloxetine-administered patient group needs to be pursued so as to be able to evaluate treatment benefits and weigh them against risks of anxiety or panic attack onset.

  9. 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.

  10. Flies and the mouth.

    PubMed

    Hassona, Yazan; Scully, Crispian; Aguida, Miranda; de Almeida, Oslei Paes

    2014-05-01

    Oral infections caused by flies are rarely encountered in clinical practice, and consequently, there is a paucity of information in the medical and dental literature about these conditions. In the present article, we present a concise review on oral myiasis or fly-blown disease. A variety of fly species can infest the oral tissues and produce an exotic clinical picture. Oral myiasis is mainly encountered in the tropics and subtropics, but can also be encountered in the western part of the world due to the increase of globalization, immigration, and global warming. Commonly-reported symptoms of oral myiasis include pain, swelling, itchy sensation, and feeling of something moving in the mouth. The surgical debridement of infected tissue with the removal of maggots is the treatment of choice in most cases of oral myiasis.

  11. 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)...

  12. 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.

  13. 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…

  14. 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

  15. Eyespots divert attacks by fish

    PubMed Central

    Kjernsmo, Karin; Merilaita, Sami

    2013-01-01

    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

  16. 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.

  17. 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.)

  18. Flying Boat Construction

    NASA Technical Reports Server (NTRS)

    1946-01-01

    Technicians are pictured installing flaps and wiring on a flying-boat model, circa 1944 (page 47). Photograph published in Winds of Change, 75th Anniversary NASA publication, by James Schultz. Photograph also published in Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen (page 209).

  19. 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)

  20. 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…

  1. 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)

  2. 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.

  3. 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

  4. 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...

  5. 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)

  6. 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.

  7. 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.

  8. Attack Vulnerability of Network Controllability

    PubMed Central

    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

  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. 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.

  11. 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.

  12. 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.

  13. 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

  14. Fly-scan ptychography

    DOE PAGES

    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.

  15. 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

  16. 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 ...

  17. 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 ...

  18. Biomechanics of knife stab attacks.

    PubMed

    Chadwick, E K; Nicol, A C; Lane, J V; Gray, T G

    1999-10-25

    Equipment, materials and methods for the measurement of the biomechanical parameters governing knife stab attacks have been developed and data have been presented that are relevant to the improvement of standards for the testing of stab-resistant materials. A six-camera Vicon motion analysis system was used to measure velocity, and derive energy and momentum during the approach phase of the attack and a specially developed force-measuring knife was used to measure three-dimensional forces and torque during the impact phase. The body segments associated with the knife were modelled as a series of rigid segments: trunk, upper arm, forearm and hand. The velocities of these segments, together with knowledge of the mass distribution from biomechanical tables, allowed the calculation of the individual segment energy and momentum values. The instrumented knife measured four components of load: axial force (along the length of the blade), cutting force (parallel to the breadth of the blade), lateral force (across the blade) and torque (twisting action) using foil strain gauges. Twenty volunteers were asked to stab a target with near maximal effort. Three styles of stab were used: a short thrust forward, a horizontal style sweep around the body and an overhand stab. These styles were chosen based on reported incidents, providing more realistic data than had previously existed. The 95th percentile values for axial force and energy were 1885 N and 69 J, respectively. The ability of current test methods to reproduce the mechanical parameters measured in human stab attacks has been assessed. It was found that current test methods could reproduce the range of energy and force values measured in the human stab attacks, although the simulation was not accurate in some respects. Non-axial force and torque values were also found to be significant in the human tests, but these are not reproduced in the standard mechanical tests.

  19. 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

  20. 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.

  1. Retinal degeneration in the fly.

    PubMed

    Colley, Nansi Jo

    2012-01-01

    Many genes are functionally equivalent between flies and humans. In addition, the same, or similar, mutations cause disease in both species. In fact, nearly three-fourths of all human disease genes have related sequences in Drosophila. The fly has a relatively small genome, made up of about 13,600 genes in four pairs of chromosomes. However, despite the dramatic differences in size and apparent complexity between humans and flies--we have less than twice as many genes as a fly--our genome is estimated to be made up of only 20,000-25,000 genes contained in 23 pairs of chromosomes. Therefore, despite the fly's perceived simplicity, or our perceived complexity, our genetic makeup may not be all that different. Its versatility for genetic manipulation and convenience for unraveling fundamental biological processes continue to guarantee the fly a place in the spotlight for unraveling the basis of and therapeutic treatments for human eye diseases.

  2. 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…

  3. 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,…

  4. 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.

  5. 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.

  6. 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...

  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. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. X-29 at High Angle of Attack with Smoke Generators

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This photo shows the X-29 during a 1991 research flight. Smoke generators in the nose of the aircraft were used to help researchers see the behavior of the air flowing over the aircraft. The smoke here is demonstrating forebody vortex flow. This mission was flown September 10, 1991, by NASA research pilot Rogers Smith. Two X-29 aircraft, featuring one of the most unusual designs in aviation history, flew at the Ames-Dryden Flight Research Facility (now the Dryden Flight Research Center, Edwards, California) from 1984 to 1992. The fighter-sized X-29 technology demonstrators explored several concepts and technologies including: the use of advanced composites in aircraft construction; variable-camber wing surfaces; a unique forward- swept wing and its thin supercritical airfoil; strakes; close-coupled canards; and a computerized fly-by-wire flight control system used to maintain control of the otherwise unstable aircraft. Research results showed that the configuration of forward-swept wings, coupled with movable canards, gave pilots excellent control response at angles of attack of up to 45 degrees. During its flight history, the X-29 aircraft flew 422 research missions and a total of 436 missions. Sixty of the research flights were part of the X-29 follow-on 'vortex control' phase. The forward-swept wing of the X-29 resulted in reverse airflow, toward the fuselage rather than away from it, as occurs on the usual aft-swept wing. Consequently, on the forward-swept wing, the ailerons remained unstalled at high angles of attack. This provided better airflow over the ailerons and prevented stalling (loss of lift) at high angles of attack. Introduction of composite materials in the 1970s opened a new field of aircraft construction. It also made possible the construction of the X-29's thin supercritical wing. State-of-the-art composites allowed aeroelastic tailoring which, in turn, allowed the wing some bending but limited twisting and eliminated structural divergence

  14. 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…

  15. Ballistic Beloniformes attacking through Snell's Window.

    PubMed

    Day, R D; Mueller, F; Carseldine, L; Meyers-Cherry, N; Tibbetts, I R

    2016-02-01

    Needlefishes (Beloniformes) were observed employing a range of stalking and attacking behaviours to attack schools of bait fishes ranging from the use of tactics common to predatory fishes to a novel behaviour: the use of leaping, aerial attacks. These aerial attacks are suggested to serve two purposes: to extend the attack range of the needlefishes and to reduce their prey's potential for evasion. Furthermore, a third purpose is hypothesized that the needlefishes are taking advantage of Snell's Window, an optical effect which may mask their approach to their prey.

  16. 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.

  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. 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.

  20. 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.

  1. 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....

  2. Preparedness for an anthrax attack.

    PubMed

    Franz, David R

    2009-12-01

    Bacillus anthracis is a long-known bacterial organism with a uniquely stable spore stage. Its stability and the lethal disease which results when the spore is inhaled made it a favorite of state-sponsored biological weapons programs throughout the Cold War era. It is also believed to be high on the list of candidate microbial agents which could be used by terrorist groups or lone actors. Its unique characteristics make protection of humans, especially civilians, from an intentional biological attack very difficult. The author argues that an all-hazards/public health approach - which would also be needed for any natural or deliberate outbreak, no matter the agent - should serve as a foundation of preparation for the specific anthrax countermeasures. Because B. anthracis is a unique organism, specific countermeasures for anthrax detection, diagnostics, prophylaxis and therapy, should be developed in nations or regions where the threat of biological attack is believed to warrant such preparation. Other considerations for a nation interested in anthrax preparedness are discussed.

  3. 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.

  4. 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

  5. Preparedness for an anthrax attack.

    PubMed

    Franz, David R

    2009-12-01

    Bacillus anthracis is a long-known bacterial organism with a uniquely stable spore stage. Its stability and the lethal disease which results when the spore is inhaled made it a favorite of state-sponsored biological weapons programs throughout the Cold War era. It is also believed to be high on the list of candidate microbial agents which could be used by terrorist groups or lone actors. Its unique characteristics make protection of humans, especially civilians, from an intentional biological attack very difficult. The author argues that an all-hazards/public health approach - which would also be needed for any natural or deliberate outbreak, no matter the agent - should serve as a foundation of preparation for the specific anthrax countermeasures. Because B. anthracis is a unique organism, specific countermeasures for anthrax detection, diagnostics, prophylaxis and therapy, should be developed in nations or regions where the threat of biological attack is believed to warrant such preparation. Other considerations for a nation interested in anthrax preparedness are discussed. PMID:19619577

  6. Spiroplasma Bacteria Enhance Survival of Drosophila hydei Attacked by the Parasitic Wasp Leptopilina heterotoma

    PubMed Central

    Xie, Jialei; Vilchez, Igor; Mateos, Mariana

    2010-01-01

    Background Maternally-transmitted associations between endosymbiotic bacteria and insects are ubiquitous. While many of these associations are obligate and mutually beneficial, many are facultative, and the mechanism(s) by which these microbes persist in their host lineages remain elusive. Inherited microbes with imperfect transmission are expected to be lost from their host lineages if no other mechanisms increase their persistence (i.e., host reproductive manipulation and/or fitness benefits to host). Indeed numerous facultative heritable endosymbionts are reproductive manipulators. Nevertheless, many do not manipulate reproduction, so they are expected to confer fitness benefits to their hosts, as has been shown in several studies that report defense against natural enemies, tolerance to environmental stress, and increased fecundity. Methodology/Principal Findings We examined whether larval to adult survival of Drosophila hydei against attack by a common parasitoid wasp (Leptopilina heterotoma), differed between uninfected flies and flies that were artificially infected with Spiroplasma, a heritable endosymbiont of Drosophila hydei that does not appear to manipulate host reproduction. Survival was significantly greater for Spiroplasma-infected flies, and the effect of Spiroplasma infection was most evident during the host's pupal stage. We examined whether or not increased survival of Spiroplasma-infected flies was due to reduced oviposition by the wasp (i.e., pre-oviposition mechanism). The number of wasp eggs per fly larva did not differ significantly between Spiroplasma-free and Spiroplasma-infected fly larvae, suggesting that differential fly survival is due to a post-oviposition mechanism. Conclusions/Significance Our results suggest that Spiroplasma confers protection to D. hydei against wasp parasitism. This is to our knowledge the first report of a potential defensive mutualism in the genus Spiroplasma. Whether it explains the persistence and high

  7. 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...

  8. 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.

  9. 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.

  10. "Homicide by heart attack" revisited.

    PubMed

    Turner, Staci A; Barnard, Jeffrey J; Spotswood, Sheila D; Prahlow, Joseph A

    2004-05-01

    The sudden death of a person caused by an arrhythmia that is induced by physical and/or emotional stress provoked by the criminal activity of another person is sometimes referred to as "homicide by heart attack." Published criteria for such an event relate to situations where no physical contact occurs between the perpetrator and the victim. Situations involving physical contact, but with absence of lethal injuries, are frequently treated is a similar fashion by forensic pathologists. Herein, we propose a set of modified criteria, which include cases where physical contact has occurred. Five examples of so-called "homicide by heart attack" are presented, including a 40-year-old man who was struck in the head with a wooden statue, a 74-year-old man who was punched in the jaw by a robber, a 66-year-old woman who was started awake by a home-intruder, a 67-year-old woman who struggled with a would-be purse-snatcher in a parking lot, and a 52-year-old man who was in a physical altercation with a younger man. In each instance, autopsy revealed the presence of severe, underlying heart disease, as well as absence of lethal injuries. In each case, investigative information was such that the emotional and/or physical stress associated with the criminal activity of another individual was deemed contributory to the death. The presumed mechanism of death in each case was a cardiac dysrhythmia related to underlying heart disease, but initiated by the emotional and/or physical stress.

  11. Tiger moth responses to a simulated bat attack: timing and duty cycle.

    PubMed

    Barber, J R; Conner, W E

    2006-07-01

    Many night-flying insects perform complex, aerobatic escape maneuvers when echolocating bats initiate attack. Tiger moths couple this kinematic defense with an acoustic reply to a bat's biosonar-guided assault. The jamming hypothesis for the function of these moth sounds assumes that tiger moth clicks presented at high densities, temporally locked to the terminal phase of the bat attack will produce the greatest jamming efficacy. Concomitantly, this hypothesis argues that moths warning bats of bad tasting chemicals sequestered in their tissues should call early to give the bat time to process the meaning of the warning signal and that moths calling at low duty cycles are more likely to employ such an aposematic strategy. We report here the first investigation of a tiger moth assemblage's response to playback of a bat echolocation attack sequence. This assemblage of arctiid moths first answered the echolocation attack sequence 960+/-547 ms (mean +/- s.d.) from the end of the bat attack. The assemblage reached a half-maximum response shortly after the first response, at 763+/-479 ms from the end of the terminal buzz. Tiger moth response reached a maximum at 475+/-344 ms from the end of the sequence; during the approach phase, well before the onset of the terminal buzz. In short, much of tiger moth response to bat attack occurs outside of the jamming hypotheses' predictions. Furthermore, no relationship exists between the duty cycle of a tiger moth's call (and thus the call's probability of jamming the bat) and its temporal response to bat attack. These data call into doubt the assumptions behind the jamming hypothesis as currently stated but do not directly test the functionality of arctiid sounds in disrupting echolocation in bat-moth aerial battles.

  12. 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

  13. Cued Panic Attacks in Body Dysmorphic Disorder

    PubMed Central

    Phillips, Katharine A.; Menard, William; Bjornsson, Andri S.

    2013-01-01

    Background Body dysmorphic disorder (BDD) is a common and often severe disorder. Clinical observations suggest that panic attacks triggered by BDD symptoms may be common. However, to our knowledge, no study has examined such panic attacks in BDD. We investigated the prevalence, clinical features, and correlates of BDD-triggered panic attacks in individuals with this disorder. Methods Panic attacks and other variables were assessed using reliable and valid measures in 76 individuals with lifetime DSM-IV BDD. Results 28.9% (95% CI, 18.5%–39.4%) of participants reported lifetime panic attacks triggered by BDD symptoms. The most common triggers of such attacks were feeling that others were looking at or scrutinizing the perceived appearance defects (61.9%), looking in the mirror at perceived defects (38.1%), and being in bright light where perceived defects would be more visible (23.8%). The most common panic attack symptoms were palpitations (86.4%), sweating (66.7%), shortness of breath (63.6%), trembling or shaking (63.6%), and fear of losing control or going crazy (63.6%). Compared to participants without such panic attacks, those with BDD-triggered panic attacks had more severe lifetime BDD, social anxiety, and depressive symptoms, as well as poorer functioning and quality of life on a number of measures. They were also less likely to be employed and more likely to have been psychiatrically hospitalized and to have had suicidal ideation due to BDD. Conclusions Panic attacks triggered by BDD-related situations appear common in individuals with this disorder. BDD-triggered panic attacks were associated with greater symptom severity and morbidity. PMID:23653076

  14. 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)

  15. 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

  16. 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.

  17. 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

  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. 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...

  20. 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

  1. 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.

  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. 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

  4. An Network Attack Modeling Method Based on MLL-AT

    NASA Astrophysics Data System (ADS)

    Fen, Yan; Xinchun, Yin; Hao, Huang

    In this paper, the method of modeling attack using attack tree is researched. The main goal is effectively using attack tree to model and express multi-stage network attacks. We expand and improve the traditional attack tree. The attack nodes in traditional attack tree are redefined, and the attack risk of leaf node is quantified. On those basis, the mentality and method of building MLL-AT (Multi-Level & Layer Attack Tree) are proposed. The improved attack tree can model attack more accurately, in particular to multi-stage network attacks. And the new model can also be used to evaluate system's risk, to distinguish between varying system security threat degrees caused by different attack sequences.

  5. Pilot interface with fly by wire control systems

    NASA Technical Reports Server (NTRS)

    Melvin, W. W.

    1986-01-01

    Aircraft designers are rapidly moving toward full fly by wire control systems for transport aircraft. Aside from pilot interface considerations such as location of the control input device and its basic design such as side stick, there appears to be a desire to change the fundamental way in which a pilot applies manual control. A typical design would have the lowest order of manual control be a control wheel steering mode in which the pilot is controlling an autopilot. This deprives the pilot of the tactile sense of angle of attack which is inherent in present aircraft by virtue of certification requirements for static longitudinal stability whereby a pilot must either force the aircraft away from its trim angle of attack or trim to a new angle of attack. Whether or not an aircraft actually has positive stability, it can be made to feel to a pilot as though it does by artificial feel. Artificial feel systems which interpret pilot input as pitch rate or G rate with automatic trim have proven useful in certain military combat maneuvers, but their transposition to other more normal types of manual control may not be justified.

  6. 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

  7. 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.

  8. 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.

  9. Robust, nonlinear, high angle-of-attack control design for a supermaneuverable vehicle

    NASA Technical Reports Server (NTRS)

    Adams, Richard J.

    1993-01-01

    High angle-of-attack flight control laws are developed for a supermaneuverable fighter aircraft. The methods of dynamic inversion and structured singular value synthesis are combined into an approach which addresses both the nonlinearity and robustness problems of flight at extreme operating conditions. The primary purpose of the dynamic inversion control elements is to linearize the vehicle response across the flight envelope. Structured singular value synthesis is used to design a dynamic controller which provides robust tracking to pilot commands. The resulting control system achieves desired flying qualities and guarantees a large margin of robustness to uncertainties for high angle-of-attack flight conditions. The results of linear simulation and structured singular value stability analysis are presented to demonstrate satisfaction of the design criteria. High fidelity nonlinear simulation results show that the combined dynamics inversion/structured singular value synthesis control law achieves a high level of performance in a realistic environment.

  10. 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.

  11. 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.

  12. Attack detection in unattended sensor networks

    NASA Astrophysics Data System (ADS)

    Wu, Curt; Monnier, Camille; Fry, Gerald; Girod, Lewis; Luke, Jahn

    2010-04-01

    Because sensor networks are often deployed in hostile environments where their security and integrity may be compromised, it is essential to maximize the reliability and trustworthiness of existing and envisioned sensor networks. During operations, the sensor network must be robust to deception, node compromise, and various other attacks, while maintaining the operator's situational awareness regarding the health and integrity of the system. To address these needs, we have designed a Framework to Ensure and Assess Trustworthiness in Sensor systems (FEATS) to identify attacks on sensor system integrity and inform the operator of sensor data trustworthiness. We have developed and validated unsupervised anomaly detection algorithms for sensor data captured from an experimental acoustic sensor platform under a number of attack scenarios. The platform, which contains four audio microphones, was exposed to two physical attacks (audio filtering and audio playback) as well as a live replay attack (replaying live audio data that is captured at a remote location), which is analogous to a wormhole attack in the routing layer. With our unsupervised learning algorithms, we were able to successfully identify the presence of various attacks.

  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. 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.

  15. 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.

  16. Protecting complex infrastructures against multiple strategic attackers

    NASA Astrophysics Data System (ADS)

    Hausken, Kjell

    2011-01-01

    Infrastructures are analysed subject to defence by a strategic defender and attack by multiple strategic attackers. A framework is developed where each agent determines how much to invest in defending versus attacking each of multiple targets. A target can have economic, human and symbolic values, which generally vary across agents. Investment expenditure functions for each agent can be linear in the investment effort, concave, convex, logistic, can increase incrementally, or can be subject to budget constraints. Contest success functions (e.g., ratio and difference forms) determine the probability of a successful attack on each target, dependent on the relative investments of the defender and attackers on each target, and on characteristics of the contest. Targets can be in parallel, in series, interlinked, interdependent or independent. The defender minimises the expected damage plus the defence expenditures. Each attacker maximises the expected damage minus the attack expenditures. The number of free choice variables equals the number of agents times the number of targets, or lower if there are budget constraints. Each agent is interested in how his investments vary across the targets, and the impact on his utilities. Alternative optimisation programmes are discussed, together with repeated games, dynamic games and incomplete information. An example is provided for illustration.

  17. [Changes in the number of deer louse-flies Lipoptena cervi (Hippoboscidae) in the forests of northwestern Russia].

    PubMed

    Balashov, Iu S

    1996-01-01

    Long term observations of the abundance fluctuations of the deer louse-fly Lipoptena cervi were carried out in forest areas of the Leningrad, Novgorod and Pskov provinces in 1988-1995. The registration of the winged individuals was held in the period of the mass flight in August by the number of deer louse-flies attacking a collector man during 1 km of the pathway. The abundance of deer louse-flies was being high everywhere up to 1993, while it decreased by 8-29 times in 1994-1995. The reason of the abundance decrease of deer louse-flies is the abrupt abundance decrease of the main host, the elk Alces alces. PMID:8984438

  18. [Changes in the number of deer louse-flies Lipoptena cervi (Hippoboscidae) in the forests of northwestern Russia].

    PubMed

    Balashov, Iu S

    1996-01-01

    Long term observations of the abundance fluctuations of the deer louse-fly Lipoptena cervi were carried out in forest areas of the Leningrad, Novgorod and Pskov provinces in 1988-1995. The registration of the winged individuals was held in the period of the mass flight in August by the number of deer louse-flies attacking a collector man during 1 km of the pathway. The abundance of deer louse-flies was being high everywhere up to 1993, while it decreased by 8-29 times in 1994-1995. The reason of the abundance decrease of deer louse-flies is the abrupt abundance decrease of the main host, the elk Alces alces.

  19. Fly-By-Light Sensors

    NASA Astrophysics Data System (ADS)

    Fox, Edward V.; Snitzer, Elias

    1983-03-01

    The last decade witnessed the emergence and acceptance of Fly-by-Wire technology for advanced flight control systems. The benefits of fiber-optic technology such as low EMI susceptability, lower aircraft system weight, and lower life cycle cost may substitute Fly-by-Light technology as the accepted state-of-the-art in this decade. This paper addresses the motivation for moving toward Fly-by-Light technology and technology needs for implementation of Fly-by-Light with particular emphasis on the sensors. The paper examines the impact of increased intensity levels of man-made threats (EMI, EMP and nuclear radiation) coupled with the extensive utilization of non-conductive fuselage materials. A baseline Fly-by-Light control system highlights the key system elements of sensors, effectors, and communication which require development for fiber optics to be used. With the ongoing development of fiber-optic communication technology by the telecommunication industry, the responsibility has fallen to the controls industry to provide the generic technology development for the sensing and effector requirements. United Technologies Corporation and in particular its Hamilton Standard and Research Divisions have been developing effector and sensor technology and have applied the results of these efforts to the U.S. Navy Linear Optical Transducer and the U.S. Army Rotary Optical Transducer programs. The linear transducer is a 12-bit, 3.5-inch stroke device. The rotary is a 10-bit, 40 degrees-of-travel unit.

  20. Respiration in High Flying

    PubMed Central

    Marshall, G. Struan

    1937-01-01

    Atmospheric pressure falls, as height increases, to about one-ninth of its sea-level value at 50,000 feet. The intake of oxygen into the blood depends on the partial pressure of oxygen in the inspired air, which is about one-fifth of the atmospheric pressure. But since the gaseous content of the lungs is saturated with water vapour at body temperature, 47 mm. Hg. of the atmospheric pressure in the lungs is due to water vapour and is therefore not available for oxygen or other gases, while the alveolar air contains also an almost constant pressure of 40 mm. CO2. Mental and physical output demand an adequate partial pressure of O2; they begin to be limited as soon as this falls, and at heights above 18,000 feet are seriously reduced. Consequently in order to fly higher than about 15,000 feet it is necessary to increase the partial pressure of oxygen in the inspired air. Up to about 44,000 feet this can be done by merely raising the percentage of oxygen, usually by allowing a regulated stream of oxygen to enter a small naso-buccal mask, but preferably by a closed system in which the negative pressure of inspiration opens a valve and allows oxygen to enter a bag from which it is inspired. Beyond 44,000 feet as a limit (and a lesser height for safety) it is necessary to create a local atmospheric pressure around the pilot higher than that of the surrounding air, by enclosing him in an airtight sit or cabin in which a relatively increased pressure with a maximum value of about 2½ lb. per square inch is maintained, while he breathes pure oxygen. This device was used in the recent British world record high flight, when a height of 50,000 feet was attained. The pressure-suit used by the pilot on this occasion and the decompression chamber recently built at Farnborough are described in detail. ImagesFig. 2Fig. 3Fig. 4Fig. 5 PMID:19991176

  1. 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.

  2. Susceptibility of low-chill blueberry cultivars to Mediterranean fruit fly, oriental fruit fly, and melon fly (Diptera: Tephritidae).

    PubMed

    Follett, Peter A; Zee, Francis T; Hamasaki, Randall T; Hummer, Kim; Nakamoto, Stuart T

    2011-04-01

    No-choice tests were conducted to determine whether fruit of southern highbush blueberry, Vaccinium corymbosum L., hybrids are hosts for three invasive tephritid fruit flies in Hawaii. Fruit of various blueberry cultivars was exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), or Bactrocera cucurbitae Coquillet (melon fly) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal development and adult emergence. Each of the 15 blueberry cultivars tested were infested by oriental fruit fly and Mediterranean fruit fly, confirming that these fruit flies will oviposit on blueberry fruit and that blueberry is a suitable host for fly development. However, there was significant cultivar variation in susceptibility to fruit fly infestation. For oriental fruit fly, 'Sapphire' fruit produced an average of 1.42 puparia per g, twice as high as that of the next most susceptible cultivar 'Emerald' (0.70 puparia per g). 'Legacy', 'Biloxi', and 'Spring High' were least susceptible to infestation, producing only 0.20-0.25 oriental fruit fly puparia per g of fruit. For Mediterranean fruit fly, 'Blue Crisp' produced 0.50 puparia per g of fruit, whereas 'Sharpblue' produced only 0.03 puparia per g of fruit. Blueberry was a marginal host for melon fly. This information will aid in development of pest management recommendations for blueberry cultivars as planting of low-chill cultivars expands to areas with subtropical and tropical fruit flies. Planting of fruit fly resistant cultivars may result in lower infestation levels and less crop loss.

  3. Thatcher condemns attacks on abortion mp.

    PubMed

    1987-12-19

    The Prime Minister, Mrs Margaret Thatcher, has stepped in to condemn a series of violent attacks on Liberal MP David Alton who is trying to reduce the [Illegible word] limit on abortions from 28 to 18 weeks.

  4. 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.

  5. 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.

  6. Diabetes - preventing heart attack and stroke

    MedlinePlus

    Diabetes complications - heart; Coronary artery disease - diabetes; CAD - diabetes; Cerebrovascular disease - diabetes ... People with diabetes have a higher chance of having heart attacks and strokes. Smoking and having high blood pressure and high ...

  7. 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.

  8. 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

  9. 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.

  10. Correlations in complex networks under attack.

    PubMed

    Srivastava, Animesh; Mitra, Bivas; Ganguly, Niloy; Peruani, Fernando

    2012-09-01

    For any initially correlated network after any kind of attack where either nodes or edges are removed, we obtain general expressions for the degree-degree probability matrix and degree distribution. We show that the proposed analytical approach predicts the correct topological changes after the attack by comparing the evolution of the assortativity coefficient for different attack strategies and intensities in theory and simulations. We find that it is possible to turn an initially assortative network into a disassortative one, and vice versa, by fine-tuning removal of either nodes or edges. For an initially uncorrelated network, on the other hand, we discover that only a targeted edge-removal attack can induce such correlations. PMID:23030979

  11. Death by attack from a domestic buffalo.

    PubMed

    Bakkannavar, Shankar M; Monteiro, Francis N P; Bhagavath, Prashantha; Pradeep Kumar, G

    2010-02-01

    Attacks on humans by domestic animals causing fatal injuries are not uncommon in rural areas of India. But injuries due to buffalo gore are rarely observed in villages and are different from other casualties like stab injuries, road fatalities, etc. As the victims of buffalo attack are usually recovered from the fields or forest, the investigating officer could be mislead as to the nature of infliction of fatal injuries to a possible homicide. The injuries caused by the horns of buffaloes are of various shapes, sizes and directions. They are violent and goring in nature. The wound sustained may be contusions, lacerations, criss-cross wounds, penetration of body cavities, and sometimes fractures. In the absence of any eye witness, it becomes very difficult to believe the unsuspecting domestic water buffalo as attacker. This case is reported for its rarity, for the awareness of the possible injuries in such unnatural deaths, and factors predisposing to a buffalo attack.

  12. 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

  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. Heart Attack - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Arabic) النوبة القلبية - العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Heart Attack Srčani udar - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Heart Attack 心脏病发作 - 简体中文 (Chinese - ...

  15. 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.

  16. 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 ...

  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. Mobilization of lipids and fortification of cell wall and cuticle are important in host defense against Hessian fly

    PubMed Central

    2013-01-01

    Background 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. Results Gene sets affected by Hessian fly attack in resistant plants were found to be very different from those in susceptible plants. Differential expression of gene sets was associated with differential accumulation of intermediates in defense pathways. Our results indicated that resources were rapidly mobilized in resistant plants for defense, including extensive membrane remodeling and release of lipids, sugar catabolism, and amino acid transport and degradation. These resources were likely rapidly converted into defense molecules such as oxylipins; toxic proteins including cysteine proteases, inhibitors of digestive enzymes, and lectins; phenolics; and cell wall components. However, toxicity alone does not cause immediate lethality to Hessian fly larvae. Toxic defenses might slow down Hessian fly development and therefore give plants more time for other types of defense to become effective. Conclusion Our gene expression and metabolic profiling results suggested that remodeling and fortification of cell wall and cuticle by increased deposition of phenolics and enhanced cross-linking were likely to be crucial for insect mortality by depriving Hessian fly larvae of nutrients from host cells. The identification of a large number of genes that were differentially expressed at different time points during compatible and incompatible interactions also provided a foundation for further research on the molecular pathways that lead to wheat resistance and susceptibility to Hessian fly infestation. PMID:23800119

  19. Relationship of horn fly to face fly infestation in beef cattle.

    PubMed

    Brown, A H; Johnson, Z B; Simpson, R B; Brown, M A; Steelman, C D; Rosenkrans, C F

    1994-09-01

    Horn fly and face fly counts (n = 394) taken on 194 beef cows representing seven breed groups were used to determine the effects of horn fly and face fly counts. Breed groups included were Angus (ANI and ANII), Chianina (CA), Charolais (CH), Hereford (HH), Polled Hereford (PH), and Red Poll (RP). The breed group designated ANI consisted of small-framed cows. Total horn fly and total face fly counts were determined weekly on each cow beginning in May and ending in late October or early November in a 3-yr (1988-90) study. Face flies were not counted on the ANI and ANII breed groups in 1988. All fly counts were taken when cows were grazing Ozark upland native grass pastures with only containment fences separating breeding groups. No insecticides were used in the study. Data for analysis were the mean annual horn fly and face fly counts (averaged across weeks), spring weight and fall weights, gain/day between spring and fall weights, and skin surface area in the spring (SSAS) and fall (SSAF) for each cow. Relationships among measurements were examined by correlation and regression procedures. Horn fly count was correlated (P < .05) with face fly count, spring weight, gain/day, and SSAS (.23, .11, -.25, and .12, respectively). Correlations of horn fly count with fall weight and SSAF were non-significant. Horn fly count, breed, and the breed x horn fly count interaction were significant (P < .05) for the face fly regression.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Flying qualities from early airplanes to the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Phillips, William H.

    1988-01-01

    This paper discusses the historical development of the study of flying qualities and the evolution of flying qualities requirements. Subjects considered include the scope of flying qualities, early historical development of flying qualities, research on flying qualities requirements, human response characteristics, command control systems, gust response and its relation to flying qualities, prediction of flying qualities, discussion of the Space Shuttle and of some recent airplanes, and format of the flying qualities requirements.

  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. Flies and Campylobacter Infection of Broiler Flocks

    PubMed Central

    Skovgård, Henrik; Bang, Dang Duong; Pedersen, Karl; Dybdahl, Jens; Jespersen, Jørgen B.; Madsen, Mogens

    2004-01-01

    A total of 8.2% of flies caught outside a broiler house in Denmark had the potential to transmit Campylobacter jejuni to chickens, and hundreds of flies per day passed through the ventilation system into the broiler house. Our study suggests that flies may be an important source of Campylobacter infection of broiler flocks in summer. PMID:15496257

  3. 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…

  4. 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…

  5. 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.

  6. 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…

  7. 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)

  8. 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

  9. Bartonella spp. DNA associated with biting flies from California.

    PubMed

    Chung, Crystal Y; Kasten, Rickie W; Paff, Sandra M; Van Horn, Brian A; Vayssier-Taussat, Muriel; Boulouis, Henri-Jean; Chomel, Bruno B

    2004-07-01

    Bartonella DNA was investigated in 104 horn flies (Haematobia spp.), 60 stable flies (Stomoxys spp.), 11 deer flies (Chrysops spp.), and 11 horse flies (Tabanus spp.) collected on cattle in California. Partial sequencing indicated B. bovis DNA in the horn fly pool and B. henselae type M DNA in one stable fly. PMID:15324557

  10. Pathologic features of fatal shark attacks.

    PubMed

    Byard, R W; Gilbert, J D; Brown, K

    2000-09-01

    To examine the pattern of injuries in cases of fatal shark attack in South Australian waters, the authors examined the files of their institution for all cases of shark attack in which full autopsies had been performed over the past 25 years, from 1974 to 1998. Of the seven deaths attributed to shark attack during this period, full autopsies were performed in only two cases. In the remaining five cases, bodies either had not been found or were incomplete. Case 1 was a 27-year-old male surfer who had been attacked by a shark. At autopsy, the main areas of injury involved the right thigh, which displayed characteristic teeth marks, extensive soft tissue damage, and incision of the femoral artery. There were also incised wounds of the right wrist. Bony injury was minimal, and no shark teeth were recovered. Case 2 was a 26-year-old male diver who had been attacked by a shark. At autopsy, the main areas of injury involved the left thigh and lower leg, which displayed characteristic teeth marks, extensive soft tissue damage, and incised wounds of the femoral artery and vein. There was also soft tissue trauma to the left wrist, with transection of the radial artery and vein. Bony injury was minimal, and no shark teeth were recovered. In both cases, death resulted from exsanguination following a similar pattern of soft tissue and vascular damage to a leg and arm. This type of injury is in keeping with predator attack from underneath or behind, with the most severe injuries involving one leg. Less severe injuries to the arms may have occurred during the ensuing struggle. Reconstruction of the damaged limb in case 2 by sewing together skin, soft tissue, and muscle bundles not only revealed that no soft tissue was missing but also gave a clearer picture of the pattern of teeth marks, direction of the attack, and species of predator.

  11. 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...

  12. 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.

  13. 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) • ...

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. A Traceability Attack against e-Passports

    NASA Astrophysics Data System (ADS)

    Chothia, Tom; Smirnov, Vitaliy

    Since 2004, many nations have started issuing "e-passports" containing an RFID tag that, when powered, broadcasts information. It is claimed that these passports are more secure and that our data will be protected from any possible unauthorised attempts to read it. In this paper we show that there is a flaw in one of the passport's protocols that makes it possible to trace the movements of a particular passport, without having to break the passport's cryptographic key. All an attacker has to do is to record one session between the passport and a legitimate reader, then by replaying a particular message, the attacker can distinguish that passport from any other. We have implemented our attack and tested it successfully against passports issued by a range of nations.

  20. Resistance of the double random phase encryption against various attacks.

    PubMed

    Frauel, Yann; Castro, Albertina; Naughton, Thomas J; Javidi, Bahram

    2007-08-01

    Several attacks are proposed against the double random phase encryption scheme. These attacks are demonstrated on computer-generated ciphered images. The scheme is shown to be resistant against brute force attacks but susceptible to chosen and known plaintext attacks. In particular, we describe a technique to recover the exact keys with only two known plain images. We compare this technique to other attacks proposed in the literature.

  1. 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.

  2. 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

  3. 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.

  4. Identifying inference attacks against healthcare data repositories

    PubMed Central

    Vaidya, Jaideep; Shafiq, Basit; Jiang, Xiaoqian; Ohno-Machado, Lucila

    Health care data repositories play an important role in driving progress in medical research. Finding new pathways to discovery requires having adequate data and relevant analysis. However, it is critical to ensure the privacy and security of the stored data. In this paper, we identify a dangerous inference attack against naive suppression based approaches that are used to protect sensitive information. We base our attack on the querying system provided by the Healthcare Cost and Utilization Project, though it applies in general to any medical database providing a query capability. We also discuss potential solutions to this problem. PMID:24303279

  5. 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.

  6. 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.

  7. 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

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

    PubMed

    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-realistic 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

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

    PubMed

    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-realistic 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.

  10. 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

  11. 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.

  12. Bifurcation analysis of nonlinear stability of aircraft at high angles of attack

    NASA Technical Reports Server (NTRS)

    Hui, W. H.; Tobak, M.

    1982-01-01

    The problem of stability of steady flight of an aircraft flying at high angles of attack subject to finite-amplitude disturbances in pitch is studied using bifurcation theory, taking account of the interactions between the pitching motion and the unsteady flow. The aerodynamic responses to large-amplitude slow oscillations of the aircraft are obtained from that of infinitesimal amplitude case. Increasing the angle of attack past some critical angle for which the damping vanishes, the steady flight becomes unstable and Hopf bifurcation sets in, resulting in a periodic motion. A simple criterion in terms of the aerodynamic coefficients is given for determining the stability of the bifurcating period motion. For supersonic/hypersonic flat plate airfoils the bifurcating periodic motion is found to be unstable. This implies that when the angle of attack is increased past that of neutral damping, there will be drastic changes of the motion of the aircraft from its steady flight condition at the critical angle, including, e.g. hysteresis.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. Triage of casualties after nuclear attack.

    PubMed

    Pledger, H G

    1986-09-20

    Casualties from a nuclear attack on the United Kingdom would overwhelm the health services, and health workers would be faced with many more people seeking help than could be offered treatment. Discussion is needed to determine which methods of medical and non-medical triage would be acceptable and feasible.

  18. The anthrax attacks 10 years later.

    PubMed

    Bush, Larry M; Perez, Maria T

    2012-01-01

    Ten years ago, just weeks after the September 11 attacks, the United States experienced a deliberate act of bioterrorism. Through use of the postal service, anthrax spores were widely disseminated, including to homes, the Senate, and major newsrooms, resulting in morbidity and mortality and effectively disrupting our way of life and revealing our vulnerability. Even though such attacks had been the subject of much writing and had been planned for, detection of and the appropriate response to an attack with an agent from the so-called "Category 'A' List" had only been considered in theoretical terms. What transpired during the following difficult weeks, including how public health and federal government agencies performed, has been both praised and criticized. An intertwined epidemiologic and criminal investigation of such magnitude was unprecedented in U.S. history. To address the question of whether we as a nation are now better prepared for future threats involving biologic agents, it is important to learn from the lessons of the 2001 anthrax attacks, including the critical role of clinicians in surveillance. As physicians involved in diagnosing anthrax in the index case and alerting authorities, we offer our perspective on these events a decade after their occurrence. PMID:21969275

  19. 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...

  20. 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…

  1. 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…

  2. 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)

  3. 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…

  4. 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…

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

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

    PubMed

    Mangan, Robert L; Thomas, Donald B; Moreno, Aleena Tarshis; Robacker, David

    2011-02-01

    The most common hosts for the West Indian fruit fly, Anastrepha obliqua (Macquart) (Diptera: Tephritidae) are fruit in the family Anacardiaceae (mango [Mangifera L.] and mombin [Spondias L.] species). However, similar to many of the tropical fruit flies of major economic importance, this species attacks several other families of crop fruit, including Annonaceae (cherimoya, Annona cherimola Mill.), Myrtaceae (guava, Psidium L.), Oxalidaceae (carambola, Averrhoa carambola L.), Passifloraceae (granadilla, Passiflora quadrangularis Mill.), and Sapotaceae [mamey sapote, Pouteria sapota (Jacq.) H. E. Moore & Steam]. In the family Rutaceae the economically important genus Citrus has been reported and until recently considered a host for this fruit fly. In this study, we reviewed the taxonomy of A. obliqua, tested specific chemicals that may inhibit oviposition, compared egg-to-adult survival of A. obliqua on preferred hosts and on grapefruit (Citrus X paradisi Macfad.), and measured fruit tissue-specific developmental rates of A. obliqua and the known citrus breeding Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae), from egg to pupae. Our literature review shows much confusion concerning the taxonomy of this and related Anastrepha species, including synonymies and confusion with other species. The deterrent effect of the highest concentration of flavonoids for oviposition, although significant, was not absolute. Experiments carried out under laboratory conditions showed 15-40 times greater survival of A. ludens (whose preferred hosts include Rutaceae) on grapefruit compared with A. obliqua for both tree attached and harvested fruit. Experiments of survival of developing stages over time showed that the two species oviposit into different tissues in the fruit, and mortality is much higher for the West Indian fruit fly in the flavedo and albedo of the fruit compared with the Mexican fruit fly.

  11. 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

  12. Emittance growth due to Tevatron flying wires

    SciTech Connect

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  13. Flying qualities criteria and flight control design

    NASA Technical Reports Server (NTRS)

    Berry, D. T.

    1981-01-01

    Despite the application of sophisticated design methodology, newly introduced aircraft continue to suffer from basic flying qualities deficiencies. Two recent meetings, the DOD/NASA Workshop on Highly Augmented Aircraft Criteria and the NASA Dryden Flight Research Center/Air Force Flight Test Center/AIAA Pilot Induced Oscillation Workshop, addressed this problem. An overview of these meetings is provided from the point of view of the relationship between flying qualities criteria and flight control system design. Among the items discussed are flying qualities criteria development, the role of simulation, and communication between flying qualities specialists and control system designers.

  14. 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.

  15. 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.

  16. Formation Flying and Deformable Instruments

    NASA Astrophysics Data System (ADS)

    Rio, Yvon

    2009-05-01

    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.

  17. 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.

  18. 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 ...

  19. Anger, Heavy Exertion: Fast Track to A Heart Attack?

    MedlinePlus

    ... html Anger, Heavy Exertion: Fast Track to a Heart Attack? But researchers suggest that artery-clogging plaque has ... physical exertion may be triggers for a first heart attack in some people, new research suggests. In the ...

  20. Poorer Heart Attack Victims, Especially Women, Fare Worse: Study

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_161722.html Poorer Heart Attack Victims, Especially Women, Fare Worse: Study Doctors need ... 2016 THURSDAY, Oct. 27, 2016 (HealthDay News) -- Younger heart attack survivors who struggle to afford health care and ...

  1. Expected versus unexpected panic attacks: a naturalistic prospective study.

    PubMed

    Kenardy, J; Taylor, C B

    1999-01-01

    The purpose of this study was to identify factors that are associated with expectation of panic attacks as well as to validate the hypothesized tendency to identify false (panic) alarms in panic disorder. Ten women with panic disorder were assessed naturalistically using computer-assisted self-monitoring. This allowed for prospective assessment of expected versus unexpected panic attacks. Expectation of panic attacks was associated with panic occurrence, as well as elevated sense of threat or danger, anxiety, helplessness, avoidance, distress about physical symptoms, physical sensations, and catastrophic thoughts prior to the attack. In general, the state measured prior to unexpected attacks did not differ from ongoing nonpanic state. Furthermore, none of the variables measured during the attacks were able to distinguish unexpected attacks from expected attacks.

  2. 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.

  3. Cascade-based attacks on complex networks

    NASA Astrophysics Data System (ADS)

    Motter, Adilson E.; Lai, Ying-Cheng

    2002-12-01

    We live in a modern world supported by large, complex networks. Examples range from financial markets to communication and transportation systems. In many realistic situations the flow of physical quantities in the network, as characterized by the loads on nodes, is important. We show that for such networks where loads can redistribute among the nodes, intentional attacks can lead to a cascade of overload failures, which can in turn cause the entire or a substantial part of the network to collapse. This is relevant for real-world networks that possess a highly heterogeneous distribution of loads, such as the Internet and power grids. We demonstrate that the heterogeneity of these networks makes them particularly vulnerable to attacks in that a large-scale cascade may be triggered by disabling a single key node. This brings obvious concerns on the security of such systems.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Sulfate attack on cement-stabilized sand

    SciTech Connect

    Rollings, R.S.; Burkes, J.P.; Rollings, M.P.

    1999-05-01

    A 3.5-km (2.2 mi) section of a road in Georgia developed unexpected transverse bumps within 6 months after construction. The source of the bumps appeared to be expansion within the cement-stabilized base course. Laboratory examination of samples from areas showing distress revealed the presence of ettringite, a calcium sulfoaluminate the formation of which can be accompanied by severe expansion. This expansive materials was the probable cause of the volume changes causing the transverse bumps. The calcium and alumina needed to form ettringite ware available from the portland cement and the stabilized soil`s clay minerals. The source of the sulfur was identified as the well water that was mixed with the cement-stabilized base. Sulfate attack of cement-stabilized soils is a relatively infrequent problem, but it is highly destructive when it occurs. Currently, there are no firm criteria for identifying when sulfate attack of a cement-stabilized soil is a potential problem nor are there established methods of preventing the attack.

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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

  18. [Decompression sickness after diving and following flying].

    PubMed

    Laursen, S B; Grønfeldt, W; Jacobsen, E

    1999-07-26

    A case of delayed symptoms of decompression sickness (DCS) after diving and flying is reported. The diver presented with classical signs of type 2 DCS, probably caused by air travel 16 hours after SCUBA diving. Treatment with hyperbaric oxygen (HBO) in a decompression chamber was successful. Guidelines to prevent DCS for recreational divers who plan to fly after diving are presented.

  19. 14 CFR 121.549 - Flying equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 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...

  20. 14 CFR 121.549 - Flying equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 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...

  1. 14 CFR 121.549 - Flying equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 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...

  2. 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)

  3. 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.

  4. Origin, acquisition and diversification of heritable bacterial endosymbionts in louse flies and bat flies.

    PubMed

    Duron, Olivier; Schneppat, Ulrich E; Berthomieu, Arnaud; Goodman, Steven M; Droz, Boris; Paupy, Christophe; Nkoghe, Judicaël Obame; Rahola, Nil; Tortosa, Pablo

    2014-04-01

    The γ-proteobacterium Arsenophonus and its close relatives (Arsenophonus and like organisms, ALOs) are emerging as a novel clade of endosymbionts, which are exceptionally widespread in insects. The biology of ALOs is, however, in most cases entirely unknown, and it is unclear how these endosymbionts spread across insect populations. Here, we investigate this aspect through the examination of the presence, the diversity and the evolutionary history of ALOs in 25 related species of blood-feeding flies: tsetse flies (Glossinidae), louse flies (Hippoboscidae) and bat flies (Nycteribiidae and Streblidae). While these endosymbionts were not found in tsetse flies, we identify louse flies and bat flies as harbouring the highest diversity of ALO strains reported to date, including a novel ALO clade, as well as Arsenophonus and the recently described Candidatus Aschnera chinzeii. We further show that the origin of ALO endosymbioses extends deep into the evolutionary past of louse flies and bat flies, and that it probably played a major role in the ecological specialization of their hosts. The evolutionary history of ALOs is notably complex and was shaped by both vertical transmission and horizontal transfers with frequent host turnover and apparent symbiont replacement in host lineages. In particular, ALOs have evolved repeatedly and independently close relationships with diverse groups of louse flies and bat flies, as well as phylogenetically more distant insect families, suggesting that ALO endosymbioses are exceptionally dynamic systems.

  5. Pregnant stewardess--should she fly?

    PubMed

    Scholten, P

    1976-01-01

    There is much pressure on the airlines to allow stewardesses to fly while pregnant. Some of them want to fly in quite advanced stages of pregnancy. This paper offers a survey of the problem, the hazards that may occur and some guidelines for the physician. The author outlines the normal changes to be expected with advancing pregnancy and those factors that could have an adverse effect on a pregnant stewardess and her fetus, such as hypoxia, trauma, abortion, the hazards of travel, and flying itself. Certain legal problems of unemployment and medical disability also are discussed. Travel alone offers no real danger to the pregnant stewardess in the first trimester of pregnancy; however, because of the changing mechanics of her size, posture, and increasing unsteadiness, it would be wisest to require a pregnant stewardess to cease flying at 13 weeks, with an absolute prohibition of flying after the 20th week.

  6. 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

  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. 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.

  9. Geotechnical characterization of some Indian fly ashes

    SciTech Connect

    Das, S.K.; Yudhbir

    2005-10-01

    This paper reports the findings of experimental studies with regard to some common engineering properties (e.g., grain size, specific gravity, compaction characteristics, and unconfined compression strength) of both low and high calcium fly ashes, to evaluate their suitability as embankment materials and reclamation fills. In addition, morphology, chemistry, and mineralogy of fly ashes are studied using scanning electron microscope, electron dispersive x-ray analyzer, x-ray diffractometer, and infrared absorption spectroscopy. In high calcium fly ash, mineralogical and chemical differences are observed for particles, {gt}75 {mu} m and the particles of {lt} 45 {mu} m size. The mode and duration of curing significantly affect the strength and stress-strain behavior of fly ashes. The geotechnical properties of fly ash are governed by factors like lime content (CaO), iron content (Fe{sub 2}O{sub 3}) and loss on ignition. The distinct difference between self-hardening and pozzolanic reactivity has been emphasized.

  10. 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

  11. TrackFly: virtual reality for a behavioral system analysis in free-flying fruit flies.

    PubMed

    Fry, Steven N; Rohrseitz, Nicola; Straw, Andrew D; Dickinson, Michael H

    2008-06-15

    Modern neuroscience and the interest in biomimetic control design demand increasingly sophisticated experimental techniques that can be applied in freely moving animals under realistic behavioral conditions. To explore sensorimotor flight control mechanisms in free-flying fruit flies (Drosophila melanogaster), we equipped a wind tunnel with a Virtual Reality (VR) display system based on standard digital hardware and a 3D path tracking system. We demonstrate the experimental power of this approach by example of a 'one-parameter open loop' testing paradigm. It provided (1) a straightforward measure of transient responses in presence of open loop visual stimulation; (2) high data throughput and standardized measurement conditions from process automation; and (3) simplified data analysis due to well-defined testing conditions. Being based on standard hardware and software techniques, our methods provide an affordable, easy to replicate and general solution for a broad range of behavioral applications in freely moving animals. Particular relevance for advanced behavioral research tools originates from the need to perform detailed behavioral analyses in genetically modified organisms and animal models for disease research.

  12. Attack or retreat: contrasted defensive tactics used by Cyprian honeybee colonies under attack from hornets.

    PubMed

    Papachristoforou, Alexandros; Rortais, Agnès; Sueur, Jérôme; Arnold, Gérard

    2011-02-01

    This study describes the tactics used by Cyprian honeybees (Apis mellifera cypria) to defend their colonies against hornet (Vespa orientalis orientalis) attacks. We use simulated hornet attacks and a combination of video recordings and image analysis to reveal, for the first time, contrasted intra-subspecies defensive tactics that operate at the colony level during predation. In some colonies, when attacked, the numbers of guards at the hive entrance increases rapidly to attack, engulf, and kill invading hornets. In other colonies, guards avoid conflicts with hornets by retreating gradually and by forming a defensive line of honeybees at the hive entrance. Retreater colonies have propolis walls at the hive entrances with small apertures that are too narrow to allow the hornet to access the hive and that therefore reinforces entrance protection. On the contrary, attacker colonies have propolis walls with large openings through which the hornet can pass; these bees block the hornet's access by intensively guarding the hive entrance. We experimentally destroy propolis walls to test whether colonies consistently rebuild walls with the same intrinsic characteristics and we also monitor the survival rate of each anti-predator tactic after massive natural predation by hornets.

  13. 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

  14. [Psychoses and unidentified flying objects].

    PubMed

    Mavrakis, D; Bocquet, J P

    1983-04-01

    Some individuals claim to have come into contact and communicated with occupants of flying objects of extraterrestrial origin who often would have entrusted them with "missions" regarding the safeguard of humanity. The authors, who have observed six such subjects, conclude that five of them suffered from a paranoid delusional state often akin to paraphrenia; whereas other analogous cases previously reported have been diagnosed as suffering from paranoid schizophrenia. Their beliefs, inaccessible to criticism and to reasoning, presumably help them to remain outside psychiatric reach. The present article does not take an interest in the physical existence of this phenomenon and does not wish to be reductionistic. It does not claim to express a judgment on the witnesses of such phenomena whose mental health must be evaluated through a rigorous and impartial examination, and not be evaluated in terms of the examiner's preconceptions toward the witnesses' assertions.

  15. Insects as unidentified flying objects.

    PubMed

    Callahan, P S; Mankin, R W

    1978-11-01

    Five species of insects were subjected to a large electric field. Each of the insects stimulated in this manner emitted visible glows of various colors and blacklight (uv). It is postulated that the Uintah Basin, Utah, nocturnal UFO display (1965-1968) was partially due to mass swarms of spruce budworms, Choristoneura fumiferana (Clemens), stimulated to emit this type of St. Elmo's fire by flying into high electric fields caused by thunderheads and high density particulate matter in the air. There was excellent time and spatial correlation between the 1965-1968 UFO nocturnal sightings and spruce budworm infestation. It is suggested that a correlation of nocturnal UFO sightings throughout the U.S. and Canada with spruce budworm infestations might give some insight into nocturnal insect flight patterns.

  16. 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

  17. 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

  18. Trapping tsetse flies on water

    PubMed Central

    Laveissière, C.; Camara, M.; Rayaisse, J.B.; Salou, E.; Kagbadouno, M.; Solano, P.

    2011-01-01

    Riverine tsetse flies such as Glossina palpalis gambiensis and G. tachinoides are the vectors of human and animal trypanosomoses in West Africa. Despite intimate links between tsetse and water, to our knowledge there has never been any attempt to design trapping devices that would catch tsetse on water. In mangrove (Guinea) one challenging issue is the tide, because height above the ground for a trap is a key factor affecting tsetse catches. The trap was mounted on the remains of an old wooden dugout, and attached with rope to nearby branches, thereby allowing it to rise and fall with the tide. Catches showed a very high density of 93.9 flies/”water-trap”/day, which was significantly higher (p < 0.05) than all the catches from other habitats where the classical trap had been used. In savannah, on the Comoe river of South Burkina Faso, the biconical trap was mounted on a small wooden raft anchored to a stone, and catches were compared with the classical biconical trap put on the shores. G. p. gambiensis and G. tachinoides densities were not significantly different from those from the classical biconical one. The adaptations described here have allowed to efficiently catch tsetse on the water, which to our knowledge is reported here for the first time. This represents a great progress and opens new opportunities to undertake studies on the vectors of trypanosomoses in mangrove areas of Guinea, which are currently the areas showing the highest prevalences of sleeping sickness in West Africa. It also has huge potential for tsetse control using insecticide impregnated traps in savannah areas where traps become less efficient in rainy season. The Guinean National control programme has already expressed its willingness to use such modified traps in its control campaigns in Guinea, as has the national PATTEC programme in Burkina Faso during rainy season. PMID:21678789

  19. Efficient certificate-based signcryption secure against public key replacement attacks and insider attacks.

    PubMed

    Lu, Yang; 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.

  20. 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

  1. 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.

  2. 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

  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

    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.

  5. 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.

  6. 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

  7. FlyBase 101--the basics of navigating FlyBase.

    PubMed

    McQuilton, Peter; St Pierre, Susan E; Thurmond, Jim

    2012-01-01

    FlyBase (http://flybase.org) is the leading database and web portal for genetic and genomic information on the fruit fly Drosophila melanogaster and related fly species. Whether you use the fruit fly as an experimental system or want to apply Drosophila biological knowledge to another field of study, FlyBase can help you successfully navigate the wealth of available Drosophila data. Here, we review the FlyBase web site with novice and less-experienced users of FlyBase in mind and point out recent developments stemming from the availability of genome-wide data from the modENCODE project. The first section of this paper explains the organization of the web site and describes the report pages available on FlyBase, focusing on the most popular, the Gene Report. The next section introduces some of the search tools available on FlyBase, in particular, our heavily used and recently redesigned search tool QuickSearch, found on the FlyBase homepage. The final section concerns genomic data, including recent modENCODE (http://www.modencode.org) data, available through our Genome Browser, GBrowse. PMID:22127867

  8. 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

  9. 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

  10. 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.

  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. Municipal solid-waste incinerator fly ash

    SciTech Connect

    Goh, A.T.C. ); Joohwa Tay )

    1993-05-01

    Many highly urbanized cities are faced with the problem of disposal of municipal solid waste because of the scarcity of land available for landfilling. One possible solution is the incineration of the municipal solid waste. After incineration, about 20% by weight of fly ash and other residues are produced. Investigations into the physical and engineering properties of the fly ash derived from municipal solid-waste incineration indicate that the material is a potential source of fill material, with low compacted density and high strength. The fly ash was relatively free draining, with permeability of the same order of magnitude as coarse grained materials. The use of the fly ash as an admixture in the stabilization of a soft marine clay showed improved undrained shear strengths and lower compressive properties. Leachate tests on the samples of fly ash initially indicated trace quantities of cadmium and chromium in excess of the acceptable drinking-water limits. After leaching for 28 days, the concentrations fell below the drinking-water limits. Lime and cement can be used to stabilize the fly ash. The concentrations of heavy metals in the leachates of lime and cement treated fly ash were nondetectable.

  13. Cardiogenic embolism producing crescendo transient ischemic attacks.

    PubMed

    Geraghty, Patrick J; Oak, Jack; Choi, Eric T

    2005-09-01

    Lateralizing, repetitive transient ischemic attacks are characteristic of symptomatic carotid bifurcation atherosclerotic plaques. We report a case in which a cardiogenic embolus, after lodging at the left carotid bifurcation, produced crescendo episodes of expressive aphasia and mild right upper extremity weakness. Complete neurological recovery was achieved following emergent carotid embolectomy and endarterectomy. This case demonstrates that the laminar nature of internal carotid blood flow may result in the localization of embolic events to a single region of the cerebral vasculature, regardless of the source lesion in the carotid artery. The role of endoluminal techniques in the diagnosis and management of such lesions is discussed.

  14. 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.

  15. Sulfate attack in lime-treated subbases

    SciTech Connect

    Day, D.C.; Salami, M.R.; Rollings, R.S.

    1995-06-01

    Sulfate-induced heave or buckling in pavements is the phenomenon that occurs when the calcium in various lime-based stabilizers combines with the alumina and sulfate present in clay to form calcium sulfoaluminate, or ettringite. Ettringite, a crystal, can grow between clay particles, pushing them apart and causing swelling in the soil. When this happens in pavement subbases, the resulting heaving may cause the pavement to rupture and fail, sometimes in a dramatic way. In this paper the authors examine the mechanism of sulfate attack, review some of the work done on this problem, and present some examples of pavement failures.

  16. Marijuana effects on simulated flying ability.

    PubMed

    Janowsky, D S; Meacham, M P; Blaine, J D; Schoor, M; Bozzetti, L P

    1976-04-01

    The authors studied the effects of marijuana intoxication on the ability of 10 certified airplane pilots to operate a flight simulator. They used a randomized double-blind crossover design to compare the effect of active versus placebo marijuana. They found that all 10 pilots showed a significant decrease in measurements of flying performance 30 minutes after smoking active marijuana. For a group of 6 pilots tested sequentially for 6 hours, a nonsignificant decrease in flying performance continued for 2 hours after smoking the active drug. The authors conclude that the effects of marijuana on flying performance may represent a sensitive indicator of the drug's psychomotor effects.

  17. Sex differences in opioid and N-methyl-D-aspartate mediated non-opioid biting fly exposure induced analgesia in deer mice.

    PubMed

    Kavaliers, M; Colwell, D D; Choleris, E

    1998-08-01

    There is evidence for sex differences in responses to noxious stimuli and in the expression and mediation of analgesia. In particular, results of investigations with swim stress and the more ethologically appropriate stress of predator odor exposure have suggested sex differences in N-methyl-D-aspartate (NMDA) receptor system involvement in the mediation of analgesia. Whether or not this sex difference generalizes to other environmental stressors is, however, not clear. Biting flies are a natural aversive stimuli commonly encountered by wild and domestic animals and humans. The present study examined the opioid and non-opioid mediated nociceptive (50 degrees C hot plate) responses of reproductive male and female deer mice, Peromyscus maniculatus, exposed to biting fly attack. A 30 min exposure to biting flies (stable flies, Stomoxys calcitrans (L.)) elicited a naloxone sensitive, opioid-mediated analgesia that was of a greater magnitude in males than in female deer mice. In contrast, a 5 min exposure to biting flies elicited a 'on-opioid' analgesia that was of similar magnitude in both sexes and insensitive to both naloxone and the specific kappa opiate antagonist, nor-binaltorphimine. In male mice this non-opioid analgesia was antagonised by the competitive NMDA antagonist, NPC 1262, while in reproductive females the biting fly-induced analgesia was insensitive to NPC 12626. These results show that there are sex differences in NMDA involvement in the mediation of the non-opioid analgesia arising from brief exposure to the stress of biting fly attack. These data from a common, natural environmental challenge support the presence of basic sex difference in NMDA involvement in the mediation of stress-induced analgesia. PMID:9766834

  18. Sex differences in opioid and N-methyl-D-aspartate mediated non-opioid biting fly exposure induced analgesia in deer mice.

    PubMed

    Kavaliers, M; Colwell, D D; Choleris, E

    1998-08-01

    There is evidence for sex differences in responses to noxious stimuli and in the expression and mediation of analgesia. In particular, results of investigations with swim stress and the more ethologically appropriate stress of predator odor exposure have suggested sex differences in N-methyl-D-aspartate (NMDA) receptor system involvement in the mediation of analgesia. Whether or not this sex difference generalizes to other environmental stressors is, however, not clear. Biting flies are a natural aversive stimuli commonly encountered by wild and domestic animals and humans. The present study examined the opioid and non-opioid mediated nociceptive (50 degrees C hot plate) responses of reproductive male and female deer mice, Peromyscus maniculatus, exposed to biting fly attack. A 30 min exposure to biting flies (stable flies, Stomoxys calcitrans (L.)) elicited a naloxone sensitive, opioid-mediated analgesia that was of a greater magnitude in males than in female deer mice. In contrast, a 5 min exposure to biting flies elicited a 'on-opioid' analgesia that was of similar magnitude in both sexes and insensitive to both naloxone and the specific kappa opiate antagonist, nor-binaltorphimine. In male mice this non-opioid analgesia was antagonised by the competitive NMDA antagonist, NPC 1262, while in reproductive females the biting fly-induced analgesia was insensitive to NPC 12626. These results show that there are sex differences in NMDA involvement in the mediation of the non-opioid analgesia arising from brief exposure to the stress of biting fly attack. These data from a common, natural environmental challenge support the presence of basic sex difference in NMDA involvement in the mediation of stress-induced analgesia.

  19. 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.

  20. 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.

  1. 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.

  2. Forewing asymmetries during auditory avoidance in flying locusts

    PubMed

    Dawson; Dawson-Scully; Robert; RobertsonÝ

    1997-01-01

    Flying locusts orient to sounds in their environment. Sounds similar to those produced by echolocating bats cause a flying locust to change its flight path. We used high-speed cinematography and videography to study changes in body posture and wing kinematics of tethered locusts in response to stimulation with bat-like sounds. Locusts showed both negative and positive phonotaxis to this stimulus. Within a few wingbeats of stimulus onset (between 126 and 226ms), locusts deflected their abdomens to one side, and the angle of the left and right forewings with respect to the dorsal­ventral body axis became asymmetrical during the downstroke. This forewing asymmetry, in which the forewing on the inside of the turn became more depressed, ranged from 20 to 45° (37±9.7°, mean ± s.d.) and was correlated with the direction and magnitude of abdomen deflection, a measure of steering in tethered, flying locusts. Hindwing stroke angle asymmetries were minimal or non-existent after stimulation. Coincident with changes in forewing asymmetry and abdomen deflection was a decrease in stroke amplitude (19±6.5°) of the forewing on the inside of the attempted turn. Motor patterns from forewing first basalar (M97) muscles showed an asymmetry in the timing of left and right depressor activation that ranged from 10.4 to 1.6ms (4.23±2.85ms). The number of spikes per depressor burst increased to a maximum of three spikes in the muscle on the inside of the attempted turn, and depressor frequency (wingbeat frequency) increased by approximately 2Hz (2.17±0.26Hz). We suggest that the asymmetry in forewing first basalar activity is causally related to the asymmetry in the timing of the initiation of the downstroke, resulting in an asymmetry in the ranges of the stroke angles of the forewings, which would impart a roll torque to the locust. This would augment the steering torques generated by concurrent changes in the angle of attack of the fore- and hindwings and changes in abdomen

  3. Error and attack tolerance of complex networks

    NASA Astrophysics Data System (ADS)

    Albert, Réka; Jeong, Hawoong; Barabási, Albert-László

    2000-07-01

    Many complex systems display a surprising degree of tolerance against errors. For example, relatively simple organisms grow, persist and reproduce despite drastic pharmaceutical or environmental interventions, an error tolerance attributed to the robustness of the underlying metabolic network. Complex communication networks display a surprising degree of robustness: although key components regularly malfunction, local failures rarely lead to the loss of the global information-carrying ability of the network. The stability of these and other complex systems is often attributed to the redundant wiring of the functional web defined by the systems' components. Here we demonstrate that error tolerance is not shared by all redundant systems: it is displayed only by a class of inhomogeneously wired networks, called scale-free networks, which include the World-Wide Web, the Internet, social networks and cells. We find that such networks display an unexpected degree of robustness, the ability of their nodes to communicate being unaffected even by unrealistically high failure rates. However, error tolerance comes at a high price in that these networks are extremely vulnerable to attacks (that is, to the selection and removal of a few nodes that play a vital role in maintaining the network's connectivity). Such error tolerance and attack vulnerability are generic properties of communication networks.

  4. 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

  5. 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.

  6. 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.

  7. Flying Through Dust From Asteroids

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-11-01

    How can we tell what an asteroid is made of? Until now, weve relied on remote spectral observations, though NASAs recently launched OSIRIS-REx mission may soon change this by landing on an asteroid and returning with a sample.But what if we could learn more about the asteroids near Earth without needing to land on each one? It turns out that we can by flying through their dust.The aerogel dust collector of the Stardust mission. [NASA/JPL/Caltech]Ejected CluesWhen an airless body is impacted by the meteoroids prevalent throughout our solar system, ejecta from the body are flung into the space around it. In the case of small objects like asteroids, their gravitational pull is so weak that most of the ejected material escapes, forming a surrounding cloud of dust.By flying a spacecraft through this cloud, we could perform chemical analysis of the dust, thereby determining the asteroids composition. We could even capture some of the dust during a flyby (for example, by using an aerogel collector like in the Stardust mission) and bring it back home to analyze.So whats the best place to fly a dust-analyzing or -collecting spacecraft? To answer this, we need to know what the typical distribution of dust is around a near-Earth asteroid (NEA) a problem that scientists Jamey Szalay (Southwest Research Institute) and Mihly Hornyi (University of Colorado Boulder) address in a recent study.The colors show the density distribution for dust grains larger than 0.3 m around a body with a 10-km radius. The distribution is asymmetric, with higher densities on the apex side, shown here in the +y direction. [Szalay Hornyi 2016]Moon as a LaboratoryTo determine typical dust distributions around NEAs, Szalay and Hornyi first look at the distribution of dust around our own Moon, caused by the same barrage of meteorites wed expect to impact NEAs. The Moons dust cloud was measured in situ in 2013 and 2014 by the Lunar Dust Experiment (LDEX) on board the Lunar Atmosphere and Dust Environment

  8. 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)...

  9. 32 CFR 855.13 - Civil fly-ins.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 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)...

  10. 32 CFR 855.13 - Civil fly-ins.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 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)...

  11. 32 CFR 855.13 - Civil fly-ins.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 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)...

  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. 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

  14. The practical difficulties of commercial flying

    NASA Technical Reports Server (NTRS)

    Courtney, F T

    1924-01-01

    This paper relates some of the problems commercial aircraft companies have in attracting larger numbers of paying customers. The author discusses some remedies such as changing the public perception of flying as dangerous.

  15. 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? ...

  16. 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...

  17. 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...

  18. 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 ...

  19. 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.

  20. Valuable products from utility fly ash

    SciTech Connect

    DeBarr, J.A.; Rapp, D.M.

    1996-10-01

    Utilization of wastes from coal combustion is becoming an issue of increasing concern to coal companies and to the utilities that burn coal. The willingness of a coal company to dispose of the waste generated when its coal is burned is an advantage in a very competitive marketplace. Recovery of relatively valuable products from utility fly ash would help offset disposal costs, and may represent a component of an overall scheme of fly ash processing where fly ash is regarded as a potential resource rather than a waste. In this study, the quantity and quality of recoverable adsorbent carbon, magnetite and cenospheres is being evaluated. Preliminary results have demonstrated that quality adsorbent carbon and magnetite products can be prepared from fly ash derived from combustion of Illinois coals.

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

    DOE PAGES

    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

  2. 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.

  3. 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

  4. 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.

  5. Relativistic Tennis Using Flying Mirror

    NASA Astrophysics Data System (ADS)

    Pirozhkov, A. S.; Kando, M.; Esirkepov, T. Zh.; 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.; Bulanov, S. V.; Kimura, T.; Kato, Y.; Tajima, T.

    2008-06-01

    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 ≈4-6×1019 cm-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 ˜55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3×107 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.

  6. 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

  7. Extended Password Recovery Attacks against APOP, SIP, and Digest Authentication

    NASA Astrophysics Data System (ADS)

    Sasaki, Yu; Wang, Lei; Ohta, Kazuo; Kunihiro, Noboru

    In this paper, we propose password recovery attacks against challenge-response authentication protocols. Our attacks use a message difference for a MD5 collision attack proposed in IEICE 2008. First, we show how to efficiently find a message pair that collides with the above message difference. Second, we show that a password used in authenticated post office protocol (APOP) can be recovered practically. We also show that the password recovery attack can be applied to a session initiation protocol (SIP) and digest authentication. Our attack can recover up to the first 31 password characters in a short time and up to the first 60 characters faster than the naive search method. We have implemented our attack and confirmed that 31 characters can be successfully recovered.

  8. Maintaining defender's reputation in anomaly detection against insider attacks.

    PubMed

    Zhang, Nan; Yu, Wei; Fu, Xinwen; Das, Sajal K

    2010-06-01

    We address issues related to establishing a defender's reputation in anomaly detection against two types of attackers: 1) smart insiders, who learn from historic attacks and adapt their strategies to avoid detection/punishment, and 2) naïve attackers, who blindly launch their attacks without knowledge of the history. In this paper, we propose two novel algorithms for reputation establishment--one for systems solely consisting of smart insiders and the other for systems in which both smart insiders and naïve attackers are present. The theoretical analysis and performance evaluation show that our reputation-establishment algorithms can significantly improve the performance of anomaly detection against insider attacks in terms of the tradeoff between detection and false positives.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Countermeasures for unintentional and intentional video watermarking attacks

    NASA Astrophysics Data System (ADS)

    Deguillaume, Frederic; Csurka, Gabriela; Pun, Thierry

    2000-05-01

    These last years, the rapidly growing digital multimedia market has revealed an urgent need for effective copyright protection mechanisms. Therefore, digital audio, image and video watermarking has recently become a very active area of research, as a solution to this problem. Many important issues have been pointed out, one of them being the robustness to non-intentional and intentional attacks. This paper studies some attacks and proposes countermeasures applied to videos. General attacks are lossy copying/transcoding such as MPEG compression and digital/analog (D/A) conversion, changes of frame-rate, changes of display format, and geometrical distortions. More specific attacks are sequence edition, and statistical attacks such as averaging or collusion. Averaging attack consists of averaging locally consecutive frames to cancel the watermark. This attack works well for schemes which embed random independent marks into frames. In the collusion attack the watermark is estimated from single frames (based on image denoising), and averaged over different scenes for better accuracy. The estimated watermark is then subtracted from each frame. Collusion requires that the same mark is embedded into all frames. The proposed countermeasures first ensures robustness to general attacks by spread spectrum encoding in the frequency domain and by the use of an additional template. Secondly, a Bayesian criterion, evaluating the probability of a correctly decoded watermark, is used for rejection of outliers, and to implement an algorithm against statistical attacks. The idea is to embed randomly chosen marks among a finite set of marks, into subsequences of videos which are long enough to resist averaging attacks, but short enough to avoid collusion attacks. The Bayesian criterion is needed to select the correct mark at the decoding step. Finally, the paper presents experimental results showing the robustness of the proposed method.

  19. Attribution Of Cyber Attacks On Process Control Systems

    NASA Astrophysics Data System (ADS)

    Hunker, Jeffrey; Hutchinson, Robert; Margulies, Jonathan

    The attribution of cyber attacks is an important problem. Attribution gives critical infrastructure asset owners and operators legal recourse in the event of attacks and deters potential attacks. This paper discusses attribution techniques along with the associated legal and technical challenges. It presents a proposal for a voluntary network of attributable activity, an important first step towards a more complete attribution methodology for the control systems community.

  20. Identification of cooling tower wood attack and methods of control

    SciTech Connect

    Song, P.; Trulear, M.G.

    1986-01-01

    Biological and chemical attack can greatly accelerate the deterioration of cooling tower wood. The damage, once inflicted, is irreversible and often results in premature and costly wood replacement. Biological attack is more serious than chemical, and is difficult to detect. Control of both types is essential for good tower maintenance A review of wood structures, types of attack and methods of control are presented. Effects of alkaline cooling water operation on wood deterioration are also discussed.

  1. 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.

  2. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text.

  3. 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.

  4. 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.

  5. Marr's Attacks: On Reductionism and Vagueness.

    PubMed

    Eliasmith, Chris; Kolbeck, Carter

    2015-04-01

    It has been suggested that Marr took the three levels he famously identifies to be independent. In this paper, we argue that Marr's view is more nuanced. Specifically, we show that the view explicitly articulated in his work attempts to integrate the levels, and in doing so results in Marr attacking both reductionism and vagueness. The result is a perspective in which both high-level information-processing constraints and low-level implementational constraints play mutually reinforcing and constraining roles. We discuss our recent work on Spaun-currently the world's largest functional brain model-that demonstrates the positive impact of this kind of unifying integration of Marr's levels. We argue that this kind of integration avoids his concerns with both reductionism and vagueness. In short, we suggest that the methods behind Spaun can be used to satisfy Marr's explicit interest in combining high-level functional and detailed mechanistic explanations.

  6. European industry attacks proposed carbon tax

    SciTech Connect

    Roberts, M.

    1995-08-09

    The European chemical industry, facing growing political support for the European Commission`s latest version of the carbon dioxide (CO{sub 2})-energy tax, has renewed its attacks on the proposed law. Simon de Bree, chairman of DSM and president of the European Chemical Industry Council (Cefic; Brussels), last week wrote to Jacques Santer, president of the commission, and Solana Madariaga, current president of Europe Union`s (EU) Council of Ministers, saying the tax was {open_quotes}totally unacceptable and irresponsible in terms of EU competitiveness.{close_quotes} He says it {open_quotes}has nothing to do anymore with the protection of the environment and has instead become a normal additional taxation, disguised, for opportunistic reasons, as an environmental protection measurement.{close_quotes}

  7. Inorganic nanoparticles engineered to attack bacteria.

    PubMed

    Miller, Kristen P; Wang, Lei; Benicewicz, Brian C; Decho, Alan W

    2015-11-01

    Antibiotics were once the golden bullet to constrain infectious bacteria. However, the rapid and continuing emergence of antibiotic resistance (AR) among infectious microbial pathogens has questioned the future utility of antibiotics. This dilemma has recently fueled the marriage of the disparate fields of nanochemistry and antibiotics. Nanoparticles and other types of nanomaterials have been extensively developed for drug delivery to eukaryotic cells. However, bacteria have very different cellular architectures than eukaryotic cells. This review addresses the chemistry of nanoparticle-based antibiotic carriers, and how their technical capabilities are now being re-engineered to attack, kill, but also non-lethally manipulate the physiologies of bacteria. This review also discusses the surface functionalization of inorganic nanoparticles with small ligand molecules, polymers, and charged moieties to achieve drug loading and controllable release.

  8. Detecting Cyber Attacks On Nuclear Power Plants

    NASA Astrophysics Data System (ADS)

    Rrushi, Julian; Campbell, Roy

    This paper proposes an unconventional anomaly detection approach that provides digital instrumentation and control (I&C) systems in a nuclear power plant (NPP) with the capability to probabilistically discern between legitimate protocol frames and attack frames. The stochastic activity network (SAN) formalism is used to model the fusion of protocol activity in each digital I&C system and the operation of physical components of an NPP. SAN models are employed to analyze links between protocol frames as streams of bytes, their semantics in terms of NPP operations, control data as stored in the memory of I&C systems, the operations of I&C systems on NPP components, and NPP processes. Reward rates and impulse rewards are defined in the SAN models based on the activity-marking reward structure to estimate NPP operation profiles. These profiles are then used to probabilistically estimate the legitimacy of the semantics and payloads of protocol frames received by I&C systems.

  9. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text. PMID:27333757

  10. 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.

  11. 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.

  12. 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.

  13. Jamming bat echolocation: the dogbane tiger moth Cycnia tenera times its clicks to the terminal attack calls of the big brown bat Eptesicus fuscus.

    PubMed

    Fullard, J H; Simmons, J A; Saillant, P A

    1994-09-01

    Certain tiger moths emit high-frequency clicks to an attacking bat, causing it to break off its pursuit. The sounds may either orient the bat by providing it with information that it uses to make an attack decision (aposematism) or they may disorient the bat by interrupting the normal flow of echo information required to complete a successful capture (startle, jamming). At what point during a bat's attack does an arctiid emit its clicks? If the sounds are aposematic, the moth should emit them early in the attack echolocation sequence in order to allow the bat time to understand their meaning. If, however, the sounds disrupt the bat's echo-processing behaviour, one would expect them to be emitted later in the attack to maximize their confusion effects. To test this, we exposed dogbane tiger moths (Cycnia tenera) to a recording of the echolocation sequence emitted by a big brown bat (Eptesicus fuscus) as it attacked a stationary target. Our results demonstrate that, at normal echolocation intensities, C. tenera does not respond to approach calls but waits until the terminal phase of the attack before emitting its clicks. This timing is evident whether the moth is stationary or flying and is largely independent of the intensity of the echolocation calls. These results support the hypothesis of a jamming effect (e.g. 'phantom echoes') and suggest that, to determine experimentally the effects of arctiid clicks on bats, it is important that the bats be tested under conditions that simulate the natural context in which this defence operates.

  14. 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

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

    PubMed

    Meng, Xue Guang; Sun, Mao

    2016-08-15

    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.

  16. Rapid mobilization of membrane lipids in wheat leaf sheaths during incompatible interactions with Hessian fly.

    PubMed

    Zhu, Lieceng; Liu, Xuming; Wang, Haiyan; Khajuria, Chitvan; Reese, John C; Whitworth, R Jeff; Welti, Ruth; Chen, Ming-Shun

    2012-07-01

    Hessian fly (HF) is a biotrophic insect that interacts with wheat on a gene-for-gene basis. We profiled changes in membrane lipids in two isogenic wheat lines: a susceptible line and its backcrossed offspring containing the resistance gene H13. Our results revealed a 32 to 45% reduction in total concentrations of 129 lipid species in resistant plants during incompatible interactions within 24 h after HF attack. A smaller and delayed response was observed in susceptible plants during compatible interactions. Microarray and real-time polymerase chain reaction analyses of 168 lipid-metabolism-related transcripts revealed that the abundance of many of these transcripts increased rapidly in resistant plants after HF attack but did not change in susceptible plants. In association with the rapid mobilization of membrane lipids, the concentrations of some fatty acids and 12-oxo-phytodienoic acid (OPDA) increased specifically in resistant plants. Exogenous application of OPDA increased mortality of HF larvae significantly. Collectively, our data, along with previously published results, indicate that the lipids were mobilized through lipolysis, producing free fatty acids, which were likely further converted into oxylipins and other defense molecules. Our results suggest that rapid mobilization of membrane lipids constitutes an important step for wheat to defend against HF attack.

  17. Protection of flying vehicles against blast loads

    NASA Astrophysics Data System (ADS)

    Silnikov, M. V.; Mikhaylin, A. I.

    2014-04-01

    Aircraft safety and security is a very important problem of nowadays. Terrorist bomb attacks on transport are most dangerous and often result in numerous victims. Threat of terrorist attacks on air transport is a nagging problem. The goal of the present paper is to present results of developing efficient air bomb inhibitors that preserve aircraft safety in case of onboard detonation of explosive equal of 2 kg TNT.

  18. Role of insects in the transmission of bovine leukosis virus: potential for transmission by stable flies, horn flies, and tabanids.

    PubMed

    Buxton, B A; Hinkle, N C; Schultz, R D

    1985-01-01

    The ability of stable flies (Stomoxys calcitrans), horn flies (Haematobia irritans), and tabanids (Diptera: Tabanidae) to transmit bovine leukosis virus (BLV) was investigated. Stable flies and horn flies were fed on blood collected from an infected cow, and the flies' mouthparts were immediately removed, placed in RPMI-1640 medium, ground, and inoculated into sheep and calves. Infection of sheep occurred with mouthparts from as few as 25 stable flies or 25 horn flies. However, sheep were not infected when removal of stable fly mouthparts was delayed greater than or equal to 1 hour after blood feeding. Infection of calves occurred after inoculation of mouthparts removed immediately after feeding from as few as 50 stable flies or 100 horn flies. Infected blood, applied by capillary action to the mouthparts (labella) of 15 deer flies (Chrysops sp) and a single horse fly (Tabanus atratus) caused infection in each of 2 sheep. Infection did not occur in 2 calves inoculated daily for 5 days with mouthparts from 50 horn flies collected after feeding on a BLV-infected steer. Four calves receiving bites from 75 stable flies interrupted from feeding on a BLV-positive cow also were not infected. Seronegative cattle held for 1 to 4 months in a screened enclosure with positive cattle in the presence of biting flies were not infected with BLV. The feeding behavior of each insect is discussed to assess their potential as vectors of BLV. PMID:2982293

  19. Retention of Escherichia coli by house fly and stable fly (Diptera: Muscidae) during pupal metamorphosis and eclosion.

    PubMed

    Rochon, K; Lysyk, T J; Selinger, L B

    2005-05-01

    Populations of Escherichia coli obtained by feeding larval house flies, Musca domestica L. and stable flies, Stomoxys calcitrans (L.), persisted through the pupal stage. The abundance of E. coli in house fly pupae increased initially then declined before adult emergence. Abundance of E. coli in stable fly pupae increased through pupal development and remained high. Infected stable fly pupal cases typically contained more E. coli than house fly pupal cases. A greater proportion of emerging adult house flies were infected with E. coli compared with stable flies; however, the abundance of E. coli on infected flies was similar between species. Adult flies contained 0.04-0.19% of the E. coli in the pupal cases. The proportion of infected house fly adults and the amount of E. coli on the infected flies were related to the levels of E. coli in the pupal cases; however, these relationships did not occur with the stable fly. Results suggest that retention of E. coli from larval to adult house flies could play a role in the transmission and spread of E. coli, whereas stable fly adults probably play a minor role in E. coli spread. However, pupae of both species have potential to act as reservoirs for E. coli.

  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. 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...

  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. Retention of Flying Skills and Refresher Training Requirements: Effects of Nonflying and Proficiency Flying.

    ERIC Educational Resources Information Center

    Wright, Robert H.

    A questionnaire survey was conducted of Army aviators who had experienced extended periods of nonflying or of flying only the minimum number of hours required by Army regulations to maintain proficiency, in order to determine the loss of flying ability experienced and the refresher training required for combat readiness. Analysis of the data…

  4. 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…

  5. PROBA-3: Precise formation flying demonstration mission

    NASA Astrophysics Data System (ADS)

    Llorente, J. S.; Agenjo, A.; Carrascosa, C.; de Negueruela, C.; Mestreau-Garreau, A.; Cropp, A.; Santovincenzo, A.

    2013-01-01

    Formation Flying (FF) has generated a strong interest in many space applications, most of them involving a significant complexity for building for example on-board large "virtual structures or distributed observatories". The implementation of these complex formation flying missions with critical dependency on this new, advanced and critical formation technology requires a thorough verification of the system behaviour in order to provide enough guarantees for the target mission success. A significant number of conceptual or preliminary designs, analyses, simulations, and HW on-ground testing have been performed during the last years, but still the limitations of the ground verification determine that enough confidence of the behaviour of the formation flying mission will only be possible by demonstration in flight of the concept and the associated technologies. PROBA-3 is the mission under development at ESA for in-flight formation flying demonstration, dedicated to obtain that confidence and the necessary flight maturity level in the formation flying technologies for those future target missions. PROBA-3 will demonstrate technologies such as formation metrology sensors (from very coarse to highest accuracy), formation control and GNC, system operability, safety, etc. During the last years, PROBA-3 has evolved from the initial CDF study at ESA, to two parallel phase A studies, followed by a change in the industrial configuration for the Bridging step between A and B phases. Currently the SRR consolidation has been completed, and the project is in the middle of the phase B. After the phase A study SENER and GMV were responsible for the Formation Flying System, within a mission core team completed by OHB-Sweden, QinetiQ Space and CASA Espacio. In this paper an overview of the PROBA-3 mission is provided, with a more detailed description of the formation flying preliminary design and results.

  6. 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

  7. Distinction of bloodstain patterns from fly artifacts.

    PubMed

    Benecke, Mark; Barksdale, Larry

    2003-11-26

    Forensic scientists may encounter blood spatter at a scene which may be pure or a mixture of fly artifacts and human bloodstains. It is important to be able to make an informed identification, or at least advanced documentation of such stains since the mechanics of production of fly artifacts are not determinable to the crime scene reconstructionist from regular police forces. We describe three cases in which experiments and crime scene reconstruction led to additional information. Case 1: Above the position of a victim, numerous blood stains of the low-high-velocity type were found. Exclusion of these stains being caused by force (but instead caused by the activity of adult blow flies) by use of the following observations that were confirmed in experiments: (a) sperm-/tadpole-like structure with length > width, (b) random directionality, and (c) mixture of round symmetrical and teardrop shaped stains. Case 2: A reddish spatter field was found on a fan chain two rooms away from the place where a dead woman was found. Localization of the spatter on the bottom end of the surface hinted strongly towards fly activity. Case 3: Double homicide; submillimeter stains were found on a lamp between the two corpses. Activity of flies was less likely compared to alternative scenario of moving lampshade and violent stabbing. PMID:14609651

  8. 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.

  9. 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 ...

  10. 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

  11. 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.

  12. 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…

  13. 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…

  14. 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

  15. [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.

  16. 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.

  17. 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.

  18. Pattern association--a key to recognition of shark attacks.

    PubMed

    Cirillo, G; James, H

    2004-12-01

    Investigation of a number of shark attacks in South Australian waters has lead to recognition of pattern similarities on equipment recovered from the scene of such attacks. Six cases are presented in which a common pattern of striations has been noted.

  19. 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,…

  20. 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…

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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.

  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. "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…

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. IVs to Skip for Immunizing WEP against FMS Attack

    NASA Astrophysics Data System (ADS)

    Kobara, Kazukuni; Imai, Hideki

    The WEP (Wired Equivalent Privacy) is a part of IEEE 802.11 standard designed for protecting over-the-air communication. While almost all of the WLAN (Wireless LAN) cards and the APs (Access Points) support WEP, a serious key recovery attack (aka FMS attack) was identified by Fluhrer et al. The FMS attack can basically be prevented by skipping IVs (Initial Values) used in the attack, but naive skip methods reveal information on the WEP key since most of them depend on the WEP key and the patterns of the skipped IV reveal it. In order to skip IVs safely, the skip patterns must be chosen carefully. In this paper, we review the attack conditions (6) and (7), whose success probability is the highest, 0.05, amongst all known conditions to guess one key-byte from one packet. Then we identify their safe skip patterns.

  14. Step to improve neural cryptography against flipping attacks.

    PubMed

    Zhou, Jiantao; Xu, Qinzhen; Pei, Wenjiang; He, Zhenya; Szu, Harold

    2004-12-01

    Synchronization of neural networks by mutual learning has been demonstrated to be possible for constructing key exchange protocol over public channel. However, the neural cryptography schemes presented so far are not the securest under regular flipping attack (RFA) and are completely insecure under majority flipping attack (MFA). We propose a scheme by splitting the mutual information and the training process to improve the security of neural cryptosystem against flipping attacks. Both analytical and simulation results show that the success probability of RFA on the proposed scheme can be decreased to the level of brute force attack (BFA) and the success probability of MFA still decays exponentially with the weights' level L. The synchronization time of the parties also remains polynomial with L. Moreover, we analyze the security under an advanced flipping attack.

  15. 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.

  16. Weak laws against acid attacks on women: an Indian perspective.

    PubMed

    Ahmad, Nehaluddin

    2012-01-01

    Acid attacks, especially on women, have seen an alarming growth in India over the last decade. While these attacks can be attributed to various factors such as the social weakness of women in a male-dominated society, the situation is exacerbated by the general neglect of the lawmakers. As acid is inexpensive and easily available, it serves as an ideal weapon for the perpetrators. Further, as this offence is bailable in certain situations, the punishment does not act as a sufficient deterrent in most cases. This paper describes the horrendous effects that acid attacks have on the victims physically, psychologically and socially. It also examines the contemporary laws governing acid attacks on victims and offenders. Ideas for a better legal approach will also be examined with special reference to acid attacks as a crime, and the validity of specific legal provisions for female victims.

  17. 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.

  18. 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...

  19. Discriminating fever behavior in house flies.

    PubMed

    Anderson, Robert D; Blanford, Simon; Jenkins, Nina E; Thomas, Matthew B

    2013-01-01

    Fever has generally been shown to benefit infected hosts. However, fever temperatures also carry costs. While endotherms are able to limit fever costs physiologically, the means by which behavioral thermoregulators constrain these costs are less understood. Here we investigated the behavioral fever response of house flies (Musca domestica L.) challenged with different doses of the fungal entomopathogen, Beauveria bassiana. Infected flies invoked a behavioral fever selecting the hottest temperature early in the day and then moving to cooler temperatures as the day progressed. In addition, flies infected with a higher dose of fungus exhibited more intense fever responses. These variable patterns of fever are consistent with the observation that higher fever temperatures had greater impact on fungal growth. The results demonstrate the capacity of insects to modulate the degree and duration of the fever response depending on the severity of the pathogen challenge and in so doing, balance the costs and benefits of fever.

  20. FlyBase: improvements to the bibliography.

    PubMed

    Marygold, Steven J; Leyland, Paul C; Seal, Ruth L; Goodman, Joshua L; Thurmond, Jim; Strelets, Victor B; Wilson, Robert J

    2013-01-01

    An accurate, comprehensive, non-redundant and up-to-date bibliography is a crucial component of any Model Organism Database (MOD). Principally, the bibliography provides a set of references that are specific to the field served by the MOD. Moreover, it serves as a backbone to which all curated biological data can be attributed. Here, we describe the organization and main features of the bibliography in FlyBase (flybase.org), the MOD for Drosophila melanogaster. We present an overview of the current content of the bibliography, the pipeline for identifying and adding new references, the presentation of data within Reference Reports and effective methods for searching and retrieving bibliographic data. We highlight recent improvements in these areas and describe the advantages of using the FlyBase bibliography over alternative literature resources. Although this article is focused on bibliographic data, many of the features and tools described are applicable to browsing and querying other datasets in FlyBase.

  1. Fly ash lung: a new pneumoconiosis

    SciTech Connect

    Golden, E.B.; Warnock, M.L.; Hulett, L.D. Jr.

    1982-01-01

    A laborer who worked in a steel mill and in a shipyard developed non-specific pulmonary interstitial fibrosis. Postmortem samples of his lung were digested, and the inorganic material present was extracted and examined using transmission electron microscopy, electron diffraction, and electron microprobe analysis. Uncoated asbestos fibers were present (1.4 x 10/sup 5//g wet lung), as well as the presence of a large number of fly ash particles (6 x 10/sup 6//g wet lung). Fly ash is the particulate material produced during coal combustion. The contribution of the asbestos to this man's lung disease is uncertain. The authors believe, based on previous studies implicating aluminium silicates in pneumoconiosis, that the fly ash, an aluminium silicate, may be a contributing factor.

  2. Fly ash lung: a new pneumoconiosis

    SciTech Connect

    Golden, E.B.; Warnock, M.L.; Hulett, L.D. Jr.; Churg, A.M.

    1982-01-01

    A laborer who worked in a steel mill and in a shipyard developed a nonspecific pulmonary interstitial fibrosis. Postmortem samples of his lung were digested, and the inorganic material present was extracted and examined using transmission electron microscopy, electron diffraction, and electron microprobe analysis. Uncoated asbestos fibers were present (1.4 X 10(5)/g wet lung), but the surprising finding was the presence of a large number of fly ash particles (6 X 10(6)/g wet lung). Fly ash, the particulate material produced during coal combustion, has not previously been reported to be present in human lung tissue. Although the contribution of the asbestos to this man's lung disease is uncertain, we believe, based on previous studies implicating aluminum silicates in pneumoconiosis, that the fly ash, an aluminum silicate, may be a contributing factor.

  3. 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.

  4. 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.

  5. Neurons under viral attack: victims or warriors?

    PubMed

    Chakraborty, Swarupa; Nazmi, Arshed; Dutta, Kallol; Basu, Anirban

    2010-01-01

    When the central nervous system (CNS) is under viral attack, defensive antiviral responses must necessarily arise from the CNS itself to rapidly and efficiently curb infections with minimal collateral damage to the sensitive, specialized and non-regenerating neural tissue. This presents a unique challenge because an intact blood-brain barrier (BBB) and lack of proper lymphatic drainage keeps the CNS virtually outside the radar of circulating immune cells that are at constant vigilance for antigens in peripheral tissues. Limited antigen presentation skills of CNS cells in comparison to peripheral tissues is because of a total lack of dendritic cells and feeble expression of major histocompatibility complex (MHC) proteins in neurons and glia. However, research over the past two decades has identified immune effector mechanisms intrinsic to the CNS for immediate tackling, attenuating and clearing of viral infections, with assistance pouring in from peripheral circulation in the form of neutralizing antibodies and cytotoxic T cells at a later stage. Specialized CNS cells, microglia and astrocytes, were regarded as sole sentinels of the brain for containing a viral onslaught but neurons held little recognition as a potential candidate for protecting itself from the proliferation and pathogenesis of neurotropic viruses. Accumulating evidence however indicates that extracellular insult causes neurons to express immune factors characteristic of lymphoid tissues. This article aims to comprehensively analyze current research on this conditional alteration in the protein expression repertoire of neurons and the role it plays in CNS innate immune response to counter viral infections.

  6. 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

  7. 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.

  8. Helicobacter pylori defense against oxidative attack.

    PubMed

    Stent, Andrew; Every, Alison L; Sutton, Philip

    2012-03-15

    Helicobacter pylori is a microaerophilic, gram-negative pathogen of the human stomach. Despite the chronic active gastritis that develops following colonization, H. pylori is able to persist unharmed in the stomach for decades. Much of the damage caused by gastric inflammation results from the accumulation of reactive oxygen/nitrogen species within the stomach environment, which can induce oxidative damage in a wide range of biological molecules. Without appropriate defenses, this oxidative damage would be able to rapidly kill nearby H. pylori, but the organism employs a range of measures, including antioxidant enzymes, biological repair systems, and inhibitors of oxidant generation, to counter the attack. Despite the variety of measures employed to defend against oxidative injury, these processes are intimately interdependent, and any deficiency within the antioxidant system is generally sufficient to cause substantial impairment of H. pylori viability and persistence. This review provides an overview of the development of oxidative stress during H. pylori gastritis and examines the methods the organism uses to survive the resultant damage.

  9. 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

  10. 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.

  11. 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,…

  12. A Novel Method for Tracking Individuals of Fruit Fly Swarms Flying in a Laboratory Flight Arena.

    PubMed

    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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Evolution: how fruit flies adapt to seasonal stresses.

    PubMed

    Williams, Karen D; Sokolowski, Marla B

    2009-01-27

    Fruit flies inhabit a wide range of latitudes, requiring adaptation to the varying local climates. A recent study reports evidence that the ability of North American flies to endure the winter involves adaptive polymorphism of the couch potato gene.

  20. Microscopic study of alkali-activated fly ash

    SciTech Connect

    Katz, A.

    1998-02-01

    The activation mechanism of fly ash in a basic environment was studied as a means to improve the reactivity of fly ash in blended cements. The experimental program included activation of fly ash by a strong base (NaOH) at different concentrations, temperatures, and water-to-fly ash ratios. It was found that the degree of reactivity, as shown by the compressive strength, increases with increasing concentration of the base (up to 4 mol of NaOH) and curing temperature (up to 90 C). Lowering the sodium hydroxide to fly ash ratio by lowering the water/fly ash ratio, while maintaining the solution concentration constant yielded a lower compressive strength in spite of the lower porosity, and the high concentration of the solution. These results indicate that activation of fly ash in blended cements depends not only on the pH of the activating ambiance but also on the ratio between the latter and the fly ash.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. Falsification Attacks against WPA-TKIP in a Realistic Environment

    NASA Astrophysics Data System (ADS)

    Todo, Yosuke; Ozawa, Yuki; Ohigashi, Toshihiro; Morii, Masakatu

    In this paper, we propose two new falsification attacks against Wi-Fi Protected Access Temporal Key Integrity Protocol (WPA-TKIP). A previous realistic attack succeeds only for a network that supports IEEE 802.11e QoS features by both an access point (AP) and a client, and it has an execution time of 12-15min, in which it recovers a message integrity code (MIC) key from an ARP packet. Our first attack reduces the execution time for recovering a MIC key. It can recover the MIC key within 7-8min. Our second attack expands its targets that can be attacked. This attack focuses on a new vulnerability of QoS packet processing, and this vulnerability can remove the condition that the AP supports IEEE 802.11e. In addition, we discovered another vulnerability by which our attack succeeds under the condition that the chipset of the client supports IEEE 802.11e even if the client disables this standard through the OS. We demonstrate that chipsets developed by several kinds of vendors have the same vulnerability.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. Cherry Consumption and the Risk of Recurrent Gout Attacks

    PubMed Central

    Zhang, Yuqing; Neogi, Tuhina; Chen, Clara; Chaisson, Christine; Hunter, David; Choi, Hyon K.

    2012-01-01

    Objective To study the relation between cherry intake and the risk of recurrent gout attacks among individuals with gout. Methods We conducted a case-crossover study to examine associations of a set of putative risk factors with recurrent gout attacks. Individuals with gout were prospectively recruited and followed online for one year. Participants were asked about the following information when experiencing a gout attack: the onset date of the gout attack, symptoms and signs, medications (including anti-gout medications), and potential risk factors (including daily intake of cherries and cherry extract) during the 2-day period prior to the gout attack. We assessed the same exposure information over 2-day control periods. We estimated the risk of recurrent gout attacks related to cherry intake using conditional logistic regression. Results Our study included 633 individuals with gout. Cherry intake over a 2-day period was associated with a 35% lower risk of gout attacks compared with no intake (multivariate odds ratio [OR] = 0.65, 95% CI: 0.50-0.85). Cherry extract intake showed a similar inverse association (multivariate OR=0.55, 95% CI: 0.30-0.98). The effect of cherry intake persisted across subgroups by sex, obesity status, purine intake, alcohol use, diuretic use, and use of anti-gout medications. When cherry intake was combined with allopurinol use, the risk of gout attacks was 75% lower than periods without either exposure (OR=0.25, 95% CI: 0.15-0.42). Conclusions These findings suggest that cherry intake is associated with a lower risk of gout attacks. PMID:23023818

  11. 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.

  12. 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

  13. Exploring Windows Domain-Level Defenses Against Authentication Attacks

    SciTech Connect

    Nichols, Jeff A. {Cyber Sciences}; Curtis, Laura

    2016-01-01

    We investigated the security resilience of the current Windows Active Directory (AD) environments to Pass-the-Hash and Pass- the-Ticket credential theft attacks. While doing this, we discovered a way to trigger the removal of all previously issued authentication credentials for a client, thus preventing their use by attackers. After triggered, the user is forced to contact the domain administrators and to authenticate to the AD to continue. This could become the basis for a response that arrests the spread of a detected attack. Operating in a virtualized XenServer environment, we were able to carefully determine and recreate the conditions necessary to cause this response.

  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. Recurrence of Panic Attacks after Influenza Vaccination: Two Case Reports

    PubMed Central

    Kim, Han-Joon; Jeon, Sang-Won; Yoon, Ho-Kyoung

    2016-01-01

    Human influenza is a contagious respiratory illness caused by the influenza virus. The influenza vaccination is recommended annually, but several adverse effects related to allergic reactions have been reported. Panic attacks are also known to occur, but no case of a panic attack adverse effect has been reported in South Korea. We present two cases of panic disorder patients whose symptoms were aggravated by the influenza vaccination. We assumed that dysregulation of T-lymphocytes in panic disorder patients could have a role in activating various kinds of cytokines and chemokines, which then can lead to panic attack aggravation. PMID:27776395

  17. 30 CFR 56.14110 - Flying or falling materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Flying or falling materials. 56.14110 Section... Equipment Safety Devices and Maintenance Requirements § 56.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or conveyors present...

  18. 30 CFR 57.14110 - Flying or falling materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flying or falling materials. 57.14110 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or...

  19. 30 CFR 56.14110 - Flying or falling materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flying or falling materials. 56.14110 Section... Equipment Safety Devices and Maintenance Requirements § 56.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or conveyors present...

  20. 14 CFR 61.110 - Night flying exceptions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Night flying exceptions. 61.110 Section 61... flying exceptions. (a) Subject to the limitations of paragraph (b) of this section, a person is not...: (1) May be issued a pilot certificate with a limitation “Night flying prohibited”; and (2)...

  1. 14 CFR 61.110 - Night flying exceptions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Night flying exceptions. 61.110 Section 61... flying exceptions. (a) Subject to the limitations of paragraph (b) of this section, a person is not...: (1) May be issued a pilot certificate with a limitation “Night flying prohibited”; and (2)...

  2. 30 CFR 57.14110 - Flying or falling materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Flying or falling materials. 57.14110 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or...

  3. 14 CFR 91.503 - Flying equipment and operating information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flying equipment and operating information... Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.503 Flying equipment... flying equipment and aeronautical charts and data, in current and appropriate form, are accessible...

  4. Pandora bullata (Entomophthorales) affecting calliphorid flies in Central Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungi are where one finds them, and if one seeks fungal pathogens affecting flies, then a garbage dump may be an ideal place to find both persistent, abundant fly populations and their fungal pathogens. An obvious fungal epizootic affecting blue bottle flies, Chrysomyia megacephala (Diptera: Calliph...

  5. Acetylcholinesterase mutations and organophosphate resistance in sand flies and mosquitoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leishmaniasis is an insect-borne disease caused by several protozoan species in the genus Leishmania, which are vectored by sand fly species in the genera Phlebotomus or Lutzomyia, depending on the sand fly species geographic range. Sand fly bites and leishmaniasis significantly impacted U.S. milita...

  6. Advanced control technology and airworthiness flying qualities requirements

    NASA Technical Reports Server (NTRS)

    Snyder, C. T.

    1976-01-01

    Flying quality requirements are specified in terms of the complete pilot-airframe-systems loop, the task, and the environment. Results from a study of flying qualities are reported. A review of the treatment of failure cases in various flying quality requirements is presented along with a description of the methods used and relevant lessons learned from recent Autoland certification programs.

  7. 30 CFR 56.14110 - Flying or falling materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Flying or falling materials. 56.14110 Section... Equipment Safety Devices and Maintenance Requirements § 56.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or conveyors present...

  8. 14 CFR 91.503 - Flying equipment and operating information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flying equipment and operating information... Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.503 Flying equipment... flying equipment and aeronautical charts and data, in current and appropriate form, are accessible...

  9. 30 CFR 57.14110 - Flying or falling materials.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Flying or falling materials. 57.14110 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or...

  10. 30 CFR 56.14110 - Flying or falling materials.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Flying or falling materials. 56.14110 Section... Equipment Safety Devices and Maintenance Requirements § 56.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or conveyors present...

  11. 30 CFR 57.14110 - Flying or falling materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Flying or falling materials. 57.14110 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or...

  12. 14 CFR 91.503 - Flying equipment and operating information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flying equipment and operating information... Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.503 Flying equipment... flying equipment and aeronautical charts and data, in current and appropriate form, are accessible...

  13. 30 CFR 57.14110 - Flying or falling materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Flying or falling materials. 57.14110 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or...

  14. 14 CFR 61.110 - Night flying exceptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Night flying exceptions. 61.110 Section 61... flying exceptions. (a) Subject to the limitations of paragraph (b) of this section, a person is not...: (1) May be issued a pilot certificate with a limitation “Night flying prohibited”; and (2)...

  15. 14 CFR 91.503 - Flying equipment and operating information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Flying equipment and operating information... Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.503 Flying equipment... flying equipment and aeronautical charts and data, in current and appropriate form, are accessible...

  16. 30 CFR 56.14110 - Flying or falling materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Flying or falling materials. 56.14110 Section... Equipment Safety Devices and Maintenance Requirements § 56.14110 Flying or falling materials. In areas where flying or falling materials generated from the operation of screens, crushers, or conveyors present...

  17. 14 CFR 61.110 - Night flying exceptions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Night flying exceptions. 61.110 Section 61... flying exceptions. (a) Subject to the limitations of paragraph (b) of this section, a person is not...: (1) May be issued a pilot certificate with a limitation “Night flying prohibited”; and (2)...

  18. 14 CFR 61.110 - Night flying exceptions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Night flying exceptions. 61.110 Section 61... flying exceptions. (a) Subject to the limitations of paragraph (b) of this section, a person is not...: (1) May be issued a pilot certificate with a limitation “Night flying prohibited”; and (2)...

  19. Improve California trap programs for detection of fruit flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are >160,000 federal and state fruit fly detection traps deployed in southern and western U.S. States and Puerto Rico. In California alone, >100,000 traps are deployed and maintained just for exotic fruit flies detection. Fruit fly detection and eradication requires deployment of large numbers...

  20. 7 CFR 29.3151 - Flyings (X Group).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... degree of maturity and the most open leaf structure. Flyings show a material amount of injury... Buff Flyings. Tissuey, mellow, open to porous, even, clear finish, strong color intensity, 95 percent uniform, and 5 percent injury tolerance. X2L Fine Buff Flyings. Tissuey, mellow, open to porous,...

  1. 7 CFR 29.3151 - Flyings (X Group).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... degree of maturity and the most open leaf structure. Flyings show a material amount of injury... Buff Flyings. Tissuey, mellow, open to porous, even, clear finish, strong color intensity, 95 percent uniform, and 5 percent injury tolerance. X2L Fine Buff Flyings. Tissuey, mellow, open to porous,...

  2. 7 CFR 29.3151 - Flyings (X Group).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... degree of maturity and the most open leaf structure. Flyings show a material amount of injury... Buff Flyings. Tissuey, mellow, open to porous, even, clear finish, strong color intensity, 95 percent uniform, and 5 percent injury tolerance. X2L Fine Buff Flyings. Tissuey, mellow, open to porous,...

  3. 7 CFR 29.3151 - Flyings (X Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... degree of maturity and the most open leaf structure. Flyings show a material amount of injury... Buff Flyings. Tissuey, mellow, open to porous, even, clear finish, strong color intensity, 95 percent uniform, and 5 percent injury tolerance. X2L Fine Buff Flyings. Tissuey, mellow, open to porous,...

  4. 7 CFR 29.3151 - Flyings (X Group).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... degree of maturity and the most open leaf structure. Flyings show a material amount of injury... Buff Flyings. Tissuey, mellow, open to porous, even, clear finish, strong color intensity, 95 percent uniform, and 5 percent injury tolerance. X2L Fine Buff Flyings. Tissuey, mellow, open to porous,...

  5. Caribbean Fruit Fly (Diptera: Tephritidae) and Small Fruit in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tephritid fruit flies are among the most important pests of fruits and vegetables worldwide. The Caribbean fruit fly, Anastrepha suspensa (Loew), is a tephritid pest that became established in Florida following introduction in 1965. Populations of this fruit fly also occur in Puerto Rico and Cuba, ...

  6. Ka-Band Autonomous Formation Flying Sensor

    NASA Technical Reports Server (NTRS)

    Tien, Jeffrey; Purcell, George, Jr.; Srinivasan, Jeffrey; Ciminera, Michael; Srinivasan, Meera; Meehan, Thomas; Young, Lawrence; Aung, MiMi; Amaro, Luis; Chong, Yong; Quirk, Kevin

    2004-01-01

    Ka-band integrated range and bearing-angle formation sensor called the Autonomous Formation Flying (AFF) Sensor has been developed to enable deep-space formation flying of multiple spacecraft. The AFF Sensor concept is similar to that of the Global Positioning System (GPS), but the AFF Sensor would not use the GPS. The AFF Sensor would reside in radio transceivers and signal-processing subsystems aboard the formation-flying spacecraft. A version of the AFF Sensor has been developed for initial application to the two-spacecraft StarLight optical-interferometry mission, and several design investigations have been performed. From the prototype development, it has been concluded that the AFF Sensor can be expected to measure distances and directions with standard deviations of 2 cm and 1 arc minute, respectively, for spacecraft separations ranging up to about 1 km. It has also been concluded that it is necessary to optimize performance of the overall mission through design trade-offs among the performance of the AFF Sensor, the field of view of the AFF Sensor, the designs of the spacecraft and the scientific instruments that they will carry, the spacecraft maneuvers required for formation flying, and the design of a formation-control system.

  7. A Coincidental Sound Track for "Time Flies"

    ERIC Educational Resources Information Center

    Cardany, Audrey Berger

    2014-01-01

    Sound tracks serve a valuable purpose in film and video by helping tell a story, create a mood, and signal coming events. Holst's "Mars" from "The Planets" yields a coincidental soundtrack to Eric Rohmann's Caldecott-winning book, "Time Flies." This pairing provides opportunities for upper elementary and…

  8. Fly ash utilization in flue gas desulfurization

    SciTech Connect

    Mouche, R.J.; Lin, M.J.L.

    1989-09-26

    This patent describes a method of enhancing the release of alkalinity from an aqueous suspension of finely divided fly ash. It comprises contacting the suspension for a period of time sufficient to increase the alkalinity of the aqueous suspension with a mixture comprising stearic acid and a member selected from the group consisting of hydrocarbon mineral oil, polalkylene glycol, alkylarlpolyether alcohol, and kerosene.

  9. The Aerodynamics of a Flying Sports Disc

    NASA Astrophysics Data System (ADS)

    Potts, Jonathan R.; Crowther, William J.

    2001-11-01

    The flying sports disc is a spin-stabilised axi-symmetric wing of quite remarkable design. A typical disc has an approximate elliptical cross-section and hollowed out under-side cavity, such as the Frisbee(TM) disc. An experimental study of flying disc aerodynamics, including both spinning and non-spinning tests, has been carried out in the wind tunnel. Load measurements, pressure data and flow visualisation techniques have enabled an explanation of the flow physics and provided data for free-flight simulations. A computer simulation that predicts free-flight trajectories from a given set of initial conditions was used to investigate the dynamics of a flying disc. This includes a six-degree of freedom mathematical model of disc flight mechanics, with aerodynamic coefficients derived from experimental data. A flying sports disc generates lift through forward velocity just like a conventional wing. The lift contributed by spin is insignificant and does not provide nearly enough down force to support hover. Without spin, the disc tumbles ground-ward under the influence of an unstable aerodynamic pitching moment. From a backhand throw however, spin is naturally given to the disc. The unchanged pitching moment now results in roll, due to gyroscopic precession, stabilising the disc in free-flight.

  10. Letting Your Students "Fly" in the Classroom.

    ERIC Educational Resources Information Center

    Adams, Thomas

    1997-01-01

    Students investigate the concept of motion by making simple paper airplanes and flying them in the classroom. Students are introduced to conversion factors to calculate various speeds. Additional activities include rounding decimal numbers, estimating, finding averages, making bar graphs, and solving problems. Offers ideas for extension such as…

  11. FLY ASH RECYCLE IN DRY SCRUBBING

    EPA Science Inventory

    The paper describes the effects of fly ash recycle in dry scrubbing. (Previous workers have shown that the recycle of product solids improves the utilization of slaked lime--Ca(OH)2--for sulfur dioxide (SO2) removal by spray dryers with bag filters.) In laboratory-scale experimen...

  12. The Next Best Thing to Flying.

    ERIC Educational Resources Information Center

    Sorensen, Peter

    1983-01-01

    Discusses flight simulator use in pilot training. With computer graphics, sound effects, and hydraulic thrust, pilots can learn to fly without leaving the ground. Indicates that air safety has significantly improved since the Federal Aviation Administration approved using simulators, replacing a large portion of training received in actual…

  13. W5 - If Pigs Could Fly

    NASA Astrophysics Data System (ADS)

    Cannon, Trina

    2012-10-01

    Centripetal force seems to be a challenge for students and we are typically using stoppers, string, tubes and slotted masses (that always crash to the floor). But if we use a toy that reminds them of an amusement park ride, we can get the message across and have some fun. Come and see if pigs can fly!

  14. Liquid Larval Diet for Fruit Flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit fly liquid larvae diet has been developed for rearing Bactrocera dorsalis and B. cucurbitae in small and large scales and is ready for technology transfer into factory scale. The most appropriate rearing conditions using liquid diet up-to-date have been identified as follows: (1) basic diet fo...

  15. Tephritid fruit fly transgenesis and applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tephritid fruit flies are among the most serious agricultural pests in the world, owing in large part to those species having broad host ranges including hundreds of fruits and vegetables. They are the largest group of insects subject to population control by a biologically-based systems, most notab...

  16. Lyssavirus in Indian Flying Foxes, Sri Lanka

    PubMed Central

    Gunawardena, Panduka S.; Marston, Denise A.; Ellis, Richard J.; Wise, Emma L.; Karawita, Anjana C.; Breed, Andrew C.; McElhinney, Lorraine M.; Johnson, Nicholas; Banyard, Ashley C.

    2016-01-01

    A novel lyssavirus was isolated from brains of Indian flying foxes (Pteropus medius) in Sri Lanka. Phylogenetic analysis of complete virus genome sequences, and geographic location and host species, provides strong evidence that this virus is a putative new lyssavirus species, designated as Gannoruwa bat lyssavirus. PMID:27434858

  17. Mutagenicity of fly ash particles in Paramecium

    SciTech Connect

    Smith-Sonneborn, J.; Palizzi, R.A.; Herr, C.; Fisher, G.L.

    1981-01-09

    Paramecium, a protozoan that ingests nonnutritive particulate matter, was used to determine the mutagenicity of fly ash. Heat treatment inactivated mutagens that require metabolic conversion to their active form but did not destroy all mutagenicity. Extraction of particles with hydrochloric acid, but not dimethyl sulfoxide, removed detectable mutagenic activity.

  18. Unidentified Flying Objects, A Selected Bibliography.

    ERIC Educational Resources Information Center

    Rodgers, Kay, Comp.

    This bibliography, intended for the general reader, provides selective coverage of the unidentified flying object (UFO) literature that has appeared since 1969. The coverage is limited to English language works, but does include translations and materials published abroad. Other bibliographies are listed, as are books, congressional and other…

  19. Lyssavirus in Indian Flying Foxes, Sri Lanka.

    PubMed

    Gunawardena, Panduka S; Marston, Denise A; Ellis, Richard J; Wise, Emma L; Karawita, Anjana C; Breed, Andrew C; McElhinney, Lorraine M; Johnson, Nicholas; Banyard, Ashley C; Fooks, Anthony R

    2016-08-01

    A novel lyssavirus was isolated from brains of Indian flying foxes (Pteropus medius) in Sri Lanka. Phylogenetic analysis of complete virus genome sequences, and geographic location and host species, provides strong evidence that this virus is a putative new lyssavirus species, designated as Gannoruwa bat lyssavirus. PMID:27434858

  20. Multicopter Design Challenge: Design, Fly, and Learn

    ERIC Educational Resources Information Center

    Sutton, Kevin G.; Busby, Joe R.; Kelly, Daniel P.

    2016-01-01

    A great deal of the nation's attention has turned to the sky as new technologies open the door for new opportunities with unmanned aerial vehicles (UAVs). UAVs are powered aerial vehicles that do not carry an operator, use aerodynamic forces to provide vehicle lift, and can fly autonomously or be piloted remotely. As people become accustomed to…