Air Superiority by the Numbers: Cutting Combat Air Forces in a Time of Uncertainty

DTIC Science & Technology

2014-06-01

5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) School of Advanced Air And Space Studies,,Air University,,Maxwell Air...iii ACKNOWLEDGMENTS I would first like to thank the men and women whom I have had the...interdiction role. Finally, in the midst of a growing Soviet radar-guided surface-to-air threat, “Skunk Works ” developed the first stealth attack

Attacking the Lion: A Study of Cohesion in Naval Special Warfare Operational Units

DTIC Science & Technology

2011-06-01

of Existential Courage.‖ Journal of Humanistic Psychology 44, no. 3 (Summer 2004): 279–298. ———. ―Relevance of Hardiness Assessment and Training to...stealth, teamwork, and violence of action to survive and succeed in missions against larger opponents. Developing bonds of trust between individuals and...a force that conducts kinetic action missions with an emphasis on speed, surprise, and violence of action. For the most part, this mentality

Deep Learning Method for Denial of Service Attack Detection Based on Restricted Boltzmann Machine.

PubMed

Imamverdiyev, Yadigar; Abdullayeva, Fargana

2018-06-01

In this article, the application of the deep learning method based on Gaussian-Bernoulli type restricted Boltzmann machine (RBM) to the detection of denial of service (DoS) attacks is considered. To increase the DoS attack detection accuracy, seven additional layers are added between the visible and the hidden layers of the RBM. Accurate results in DoS attack detection are obtained by optimization of the hyperparameters of the proposed deep RBM model. The form of the RBM that allows application of the continuous data is used. In this type of RBM, the probability distribution of the visible layer is replaced by a Gaussian distribution. Comparative analysis of the accuracy of the proposed method with Bernoulli-Bernoulli RBM, Gaussian-Bernoulli RBM, deep belief network type deep learning methods on DoS attack detection is provided. Detection accuracy of the methods is verified on the NSL-KDD data set. Higher accuracy from the proposed multilayer deep Gaussian-Bernoulli type RBM is obtained.

The Effects of Denial-of-Service Attacks on Secure Time-Critical Communications in the Smart Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Fengli; Li, QInghua; Mantooth, Homer Alan

2016-04-02

According to IEC 61850, many smart grid communications require messages to be delivered in a very short time. –Trip messages and sample values applied to the transmission level: 3 ms –Interlocking messages applied to the distribution level: 10 ms •Time-critical communications are vulnerable to denial-of-service (DoS) attacks –Flooding attack: Attacker floods many messages to the target network/machine. We conducted systematic, experimental study about how DoS attacks affect message delivery delays.

Research of laser stealth performance test technology

NASA Astrophysics Data System (ADS)

Chen, Zhen-xing; Shi, Sheng-bing; Han, Fu-li; Wu, Yan-lin; Song, Chun-yan

2014-09-01

Laser stealth is an important way of photoelectric stealth weapons systems. According to operational principle of laser range finder, we actively explore and study the stealth performance approval testing technology of laser stealth materials, and bring forward and establish the stealth performance field test methods of stealth efficiency evaluation. Through contrastive test of two kinds of materials, the method is correct and effective.

Evidence of a major gene from Bayesian segregation analyses of liability to osteochondral diseases in pigs.

PubMed

Kadarmideen, Haja N; Janss, Luc L G

2005-11-01

Bayesian segregation analyses were used to investigate the mode of inheritance of osteochondral lesions (osteochondrosis, OC) in pigs. Data consisted of 1163 animals with OC and their pedigrees included 2891 animals. Mixed-inheritance threshold models (MITM) and several variants of MITM, in conjunction with Markov chain Monte Carlo methods, were developed for the analysis of these (categorical) data. Results showed major genes with significant and substantially higher variances (range 1.384-37.81), compared to the polygenic variance (sigmau2). Consequently, heritabilities for a mixed inheritance (range 0.65-0.90) were much higher than the heritabilities from the polygenes. Disease allele frequencies range was 0.38-0.88. Additional analyses estimating the transmission probabilities of the major gene showed clear evidence for Mendelian segregation of a major gene affecting osteochondrosis. The variants, MITM with informative prior on sigmau2, showed significant improvement in marginal distributions and accuracy of parameters. MITM with a "reduced polygenic model" for parameterization of polygenic effects avoided convergence problems and poor mixing encountered in an "individual polygenic model." In all cases, "shrinkage estimators" for fixed effects avoided unidentifiability for these parameters. The mixed-inheritance linear model (MILM) was also applied to all OC lesions and compared with the MITM. This is the first study to report evidence of major genes for osteochondral lesions in pigs; these results may also form a basis for underpinning the genetic inheritance of this disease in other animals as well as in humans.

Simulation on change of generic satellite radar cross section via artificially created plasma sprays

NASA Astrophysics Data System (ADS)

Chung, Shen Shou Max; Chuang, Yu-Chou

2016-06-01

Recent advancements in antisatellite missile technologies have proven the effectiveness of such attacks, and the vulnerability of satellites in such exercises inspires a new paradigm in RF Stealth techniques suitable for satellites. In this paper we examine the possibility of using artificially created plasma sprays on the surface of the satellite’s main body to alter its radar cross section (RCS). First, we briefly review past research related to RF Stealth using plasma. Next, we discuss the physics between electromagnetic waves and plasma, and the RCS number game in RF Stealth design. A comparison of RCS in a generic satellite and a more complicated model is made to illustrate the effect of the RCS number game, and its meaning for a simulation model. We also run a comparison between finite-difference-time-domain (FDTD) and multilevel fast multipole method (MLFMM) codes, and find the RCS results are very close. We then compare the RCS of the generic satellite and the plasma-covered satellite. The incident radar wave is a differentiated Gaussian monopulse, with 3 dB bandwidth between 1.2 GHz and 4 GHz, and we simulate three kinds of plasma density, with a characteristic plasma frequency ω P  =  0.1, 1, and 10 GHz. The electron-neutral collision frequency ν en is set at 0.01 GHz. We found the RCS of plasma-covered satellite is not necessarily smaller than the originally satellite. When ω P is 0.1 GHz, the plasma spray behaves like a dielectric, and there is minor reduction in the RCS. When ω P is 1 GHz, the X-Y cut RCS increases. When ω P is 10 GHz, the plasma behaves more like a metal to the radar wave, and stronger RCS dependency to frequency appears. Therefore, to use plasma as an RCS adjustment tool requires careful fine-tuning of plasma density and shape, in order to achieve the so-called plasma stealth effect.

Spacetimes dressed with stealth electromagnetic fields

NASA Astrophysics Data System (ADS)

Smolić, Ivica

2018-04-01

Stealth field configurations by definition have a vanishing energy-momentum tensor, and thus do not contribute to the gravitational field equations. While only trivial fields can be stealth in Maxwell's electrodynamics, nontrivial stealth fields appear in some nonlinear models of electromagnetism. We find the necessary and sufficient conditions for the electromagnetic fields to be stealth and analyze which models admit such configurations. Furthermore, we present some concrete exact solutions, featuring a class of black holes dressed with the stealth electromagnetic hair, closely related to force-free solutions. Stealth hair does not alter the generalized Smarr formula, but may contribute to the Komar charges.

The general 2-D moments via integral transform method for acoustic radiation and scattering

NASA Astrophysics Data System (ADS)

Smith, Jerry R.; Mirotznik, Mark S.

2004-05-01

The moments via integral transform method (MITM) is a technique to analytically reduce the 2-D method of moments (MoM) impedance double integrals into single integrals. By using a special integral representation of the Green's function, the impedance integral can be analytically simplified to a single integral in terms of transformed shape and weight functions. The reduced expression requires fewer computations and reduces the fill times of the MoM impedance matrix. Furthermore, the resulting integral is analytic for nearly arbitrary shape and weight function sets. The MITM technique is developed for mixed boundary conditions and predictions with basic shape and weight function sets are presented. Comparisons of accuracy and speed between MITM and brute force are presented. [Work sponsored by ONR and NSWCCD ILIR Board.

Insider Threat Control: Using Plagiarism Detection Algorithms to Prevent Data Exfiltration in Near Real Time

DTIC Science & Technology

2013-10-01

Threats: Tools and Techniques 2 2.1 The Man-in-The-Middle ( MiTM ) Proxy 2 2.2 The Inspection Process 2 3 Installing WebDLPIndexer 4 3.1 Install JDK SE...selected open source and public-domain tools since they are freely available to the public. 2.1 The Man-in-The-Middle ( MiTM ) Proxy This report builds

Experimental demonstration of optical stealth transmission over wavelength-division multiplexing network.

PubMed

Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Tang, Yeteng; Chen, Dalei

2016-08-10

We propose and experimentally demonstrate an optical stealth transmission system over a 200 GHz-grid wavelength-division multiplexing (WDM) network. The stealth signal is processed by spectral broadening, temporal spreading, and power equalizing. The public signal is suppressed by multiband notch filtering at the stealth channel receiver. The interaction between the public and stealth channels is investigated in terms of public-signal-to-stealth-signal ratio, data rate, notch-filter bandwidth, and public channel number. The stealth signal can transmit over 80 km single-mode fiber with no error. Our experimental results verify the feasibility of optical steganography used over the existing WDM-based optical network.

Adaptive Suspicious Prevention for Defending DoS Attacks in SDN-Based Convergent Networks

PubMed Central

Dao, Nhu-Ngoc; Kim, Joongheon; Park, Minho; Cho, Sungrae

2016-01-01

The convergent communication network will play an important role as a single platform to unify heterogeneous networks and integrate emerging technologies and existing legacy networks. Although there have been proposed many feasible solutions, they could not become convergent frameworks since they mainly focused on converting functions between various protocols and interfaces in edge networks, and handling functions for multiple services in core networks, e.g., the Multi-protocol Label Switching (MPLS) technique. Software-defined networking (SDN), on the other hand, is expected to be the ideal future for the convergent network since it can provide a controllable, dynamic, and cost-effective network. However, SDN has an original structural vulnerability behind a lot of advantages, which is the centralized control plane. As the brains of the network, a controller manages the whole network, which is attractive to attackers. In this context, we proposes a novel solution called adaptive suspicious prevention (ASP) mechanism to protect the controller from the Denial of Service (DoS) attacks that could incapacitate an SDN. The ASP is integrated with OpenFlow protocol to detect and prevent DoS attacks effectively. Our comprehensive experimental results show that the ASP enhances the resilience of an SDN network against DoS attacks by up to 38%. PMID:27494411

Adaptive Suspicious Prevention for Defending DoS Attacks in SDN-Based Convergent Networks.

PubMed

Dao, Nhu-Ngoc; Kim, Joongheon; Park, Minho; Cho, Sungrae

2016-01-01

The convergent communication network will play an important role as a single platform to unify heterogeneous networks and integrate emerging technologies and existing legacy networks. Although there have been proposed many feasible solutions, they could not become convergent frameworks since they mainly focused on converting functions between various protocols and interfaces in edge networks, and handling functions for multiple services in core networks, e.g., the Multi-protocol Label Switching (MPLS) technique. Software-defined networking (SDN), on the other hand, is expected to be the ideal future for the convergent network since it can provide a controllable, dynamic, and cost-effective network. However, SDN has an original structural vulnerability behind a lot of advantages, which is the centralized control plane. As the brains of the network, a controller manages the whole network, which is attractive to attackers. In this context, we proposes a novel solution called adaptive suspicious prevention (ASP) mechanism to protect the controller from the Denial of Service (DoS) attacks that could incapacitate an SDN. The ASP is integrated with OpenFlow protocol to detect and prevent DoS attacks effectively. Our comprehensive experimental results show that the ASP enhances the resilience of an SDN network against DoS attacks by up to 38%.

Statistical Methods for Solar Flare Probability Forecasting.

DTIC Science & Technology

1980-09-01

TAu C a -. 66M7. stNIr’ICANCe .0000 -SOMEOSIS 0 IASYMEMTIC- a -. i55 MITM fLARPE- -D"NOroMT, *-.255S WITH APPLONG OCSEOE4T. 8OLa sSES 0 (S "MERrCTAX 0...8217 q~ - - -WS S0MEOSNSO 0 ASYHNETP1CI * 291312UI HLARE4 OPENS(N, - * 49645 MITM *Ec$POT OWITN E f. ONIRSVS 0 ESYHNETRICI a .36652 0I"El of HISSING ONSERVATIONS t 19 76 ILMEI

Minimally invasive transcanal myringotomy for pediatric early stage congenital cholesteatoma.

PubMed

Jang, Chul Ho; Jung, Eun Kyung; Sung, Chung Man; Kim, Seung Beom; Kim, Young Yoon; Seong, Jong Yuap; Kang, Sung Hoon; Cho, Yong Beom

2016-11-01

Recently, minimally invasive transcanal myringotomy (MITM), which is a useful surgical technique for early stage congenital cholesteatoma (CC) in children, was introduced. The purpose of this study is to evaluate the short-term surgical results of MITM in pediatric early stage CC. We retrospectively reviewed the charts of 24 patients who underwent MITM between January 2013 and October 2015. The patients' ages ranged from 1 to 16 years (mean, 2.6 years). There were 17 male and 7 female patients. The right side (n = 13) was affected twice as often as the left side (n = 11). The most common site was the anterosuperior quadrant (15 cases). The diameter of the CC on axial computed tomography images ranged from 2.8 to 5.7 mm (mean, 3.9 mm). CCs were graded according to Potsic's system: 18 cases were classified as stage I, 3 case as stage II, and 3 cases as stage III. AllCCs except 1 were closed type. In21 patients, the tympanic membrane closed naturally without recurrence. Three patients showed small persistent dry perforation. Natural closure occurred in these patients, who were treated with paper patches. MITM is a simple, effective technique for removing an early stage CC from the middle ear, and it can minimize operative time, length of hospitalization, and postoperative morbidity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Secret Shoppers: The Stealth Applicant Search for Higher Education

ERIC Educational Resources Information Center

Dupaul, Stephanie; Harris, Michael S.

2012-01-01

Stealth applicants who do not flow through the traditional admission funnel now represent nearly one-third of the national applicant pool. This study employs a consumer behavior framework to examine the behaviors of stealth applicants at a private university. The findings provide a rich illustration of how stealth applicants search for college.…

Evidence of a Major Gene From Bayesian Segregation Analyses of Liability to Osteochondral Diseases in Pigs

PubMed Central

Kadarmideen, Haja N.; Janss, Luc L. G.

2005-01-01

Bayesian segregation analyses were used to investigate the mode of inheritance of osteochondral lesions (osteochondrosis, OC) in pigs. Data consisted of 1163 animals with OC and their pedigrees included 2891 animals. Mixed-inheritance threshold models (MITM) and several variants of MITM, in conjunction with Markov chain Monte Carlo methods, were developed for the analysis of these (categorical) data. Results showed major genes with significant and substantially higher variances (range 1.384–37.81), compared to the polygenic variance (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{{\\sigma}}}_{{\\mathrm{u}}}^{2}\\end{equation*}\\end{document}). Consequently, heritabilities for a mixed inheritance (range 0.65–0.90) were much higher than the heritabilities from the polygenes. Disease allele frequencies range was 0.38–0.88. Additional analyses estimating the transmission probabilities of the major gene showed clear evidence for Mendelian segregation of a major gene affecting osteochondrosis. The variants, MITM with informative prior on \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{{\\sigma}}}_{{\\mathrm{u}}}^{2}\\end{equation*}\\end{document}, showed significant improvement in marginal distributions and accuracy of parameters. MITM with a “reduced polygenic model” for parameterization of polygenic effects avoided convergence problems and poor mixing encountered in an “individual polygenic model.” In all cases, “shrinkage estimators” for fixed effects avoided unidentifiability for these parameters. The mixed-inheritance linear model (MILM) was also applied to all OC lesions and compared with the MITM. This is the first study to report evidence of major genes for osteochondral lesions in pigs; these results may also form a basis for underpinning the genetic inheritance of this disease in other animals as well as in humans. PMID:16020792

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…

Develop a solution for protecting and securing enterprise networks from malicious attacks

NASA Astrophysics Data System (ADS)

Kamuru, Harshitha; Nijim, Mais

2014-05-01

In the world of computer and network security, there are myriad ways to launch an attack, which, from the perspective of a network, can usually be defined as "traffic that has huge malicious intent." Firewall acts as one of the measure in order to secure the device from incoming unauthorized data. There are infinite number of computer attacks that no firewall can prevent, such as those executed locally on the machine by a malicious user. From the network's perspective, there are numerous types of attack. All the attacks that degrade the effectiveness of data can be grouped into two types: brute force and precision. The Firewall that belongs to Juniper has the capability to protect against both types of attack. Denial of Service (DoS) attacks are one of the most well-known network security threats under brute force attacks, which is largely due to the high-profile way in which they can affect networks. Over the years, some of the largest, most respected Internet sites have been effectively taken offline by Denial of Service (DOS) attacks. A DoS attack typically has a singular focus, namely, to cause the services running on a particular host or network to become unavailable. Some DoS attacks exploit vulnerabilities in an operating system and cause it to crash, such as the infamous Win nuke attack. Others submerge a network or device with traffic so that there are no more resources to handle legitimate traffic. Precision attacks typically involve multiple phases and often involves a bit more thought than brute force attacks, all the way from reconnaissance to machine ownership. Before a precision attack is launched, information about the victim needs to be gathered. This information gathering typically takes the form of various types of scans to determine available hosts, networks, and ports. The hosts available on a network can be determined by ping sweeps. The available ports on a machine can be located by port scans. Screens cover a wide variety of attack traffic as they are configured on a per-zone basis. Depending on the type of screen being configured, there may be additional settings beyond simply blocking the traffic. Attack prevention is also a native function of any firewall. Juniper Firewall handles traffic on a per-flow basis. We can use flows or sessions as a way to determine whether traffic attempting to traverse the firewall is legitimate. We control the state-checking components resident in Juniper Firewall by configuring "flow" settings. These settings allow you to configure state checking for various conditions on the device. You can use flow settings to protect against TCP hijacking, and to generally ensure that the fire-wall is performing full state processing when desired. We take a case study of attack on a network and perform study of the detection of the malicious packets on a Net screen Firewall. A new solution for securing enterprise networks will be developed here.

DoS detection in IEEE 802.11 with the presence of hidden nodes

PubMed Central

Soryal, Joseph; Liu, Xijie; Saadawi, Tarek

2013-01-01

The paper presents a novel technique to detect Denial of Service (DoS) attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF) protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel’s bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and the results are presented to validate the algorithm. PMID:25685510

DoS detection in IEEE 802.11 with the presence of hidden nodes.

PubMed

Soryal, Joseph; Liu, Xijie; Saadawi, Tarek

2014-07-01

The paper presents a novel technique to detect Denial of Service (DoS) attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF) protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel's bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and the results are presented to validate the algorithm.

The preparation and infrared radar stealth performance test of a new paraffin-based phase transition microcapsule

NASA Astrophysics Data System (ADS)

Chen, Yingming; Zhang, Honghong; Gao, Weiting; Chen, Yingmin; Wang, Yifan

2018-04-01

For the problems that the phase change material apply to infrared stealth exists easy to broken, hard to control temperature, narrow infrared channel and based on the basic principles of infrared stealth technology, this paper proposed a scheme of thermal infrared composite invisibility multi-layer wrapping, which based on two sides, one is to control the material surface temperature, another is to reduce its infrared emissivity and combine with visible light pigment and electromagnetic wave absorbing material, to realize the materials' wide band compatible stealth. First, choose urea formaldehyde resin and paraffin to prepare multiphase-change microcapsules, and then combine it with the ferroferric oxide absorbing material, zinc oxide visible light pigment, to make the stealth material of wide band. The experimental results show that the new phase change capsule can realize the function of temperature control and infrared stealth in a special temperature range.

Surgical outcomes of early congenital cholesteatoma: minimally invasive transcanal approach.

PubMed

Lee, Sang H; Jang, Jeong H; Lee, Dongjun; Lee, Hye-Ryung; Lee, Kyu-Yup

2014-03-01

To introduce a simple and alternative surgical technique, minimally invasive transcanal myringotomy (MITM), for early stage congenital cholesteatoma in children and to evaluate the feasibility and results of MITM for management of early stage congenital cholesteatoma with respect to its effectiveness and safety. Retrospective review. Between August 2008 and September 2012, a total of 36 patients with congenital cholesteatoma met the inclusion criteria and were analyzed. Patient medical records, including demographic characteristics, intraoperative findings, and follow-up records, were reviewed. Subjects consisted of 23 males (64%) and 13 females (36%), and the age at operation ranged from 12 months to 6 years (mean age = 3 years and 6 months). The number of congenital cholesteatoma was as follows: 26 patients at stage I and 10 patients at stage II. The follow-up duration was between 12 and 56 months, with an average of 30 months. There were no postoperative complications such as tympanic membrane perforation, dizziness, or secondary middle ear infection. Among 36 patients who had undergone the MITM approach for the treatment of congenital cholesteatoma, five (13.8%) showed recurrence and underwent a second-look operation. On the basis of our data, the MITM approach is a useful surgical technique for early stage congenital cholesteatoma in children. It has many advantages, in that there is no external wound and it is a simple surgical technique that involves easy postoperative care, a short operation time and hospitalization period, avoidance of serious complications, and easy repeatability for recurrence. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Factorial design studies of antiretroviral drug-loaded stealth liposomal injectable: PEGylation, lyophilization and pharmacokinetic studies

NASA Astrophysics Data System (ADS)

Sudhakar, Beeravelli; Krishna, Mylangam Chaitanya; Murthy, Kolapalli Venkata Ramana

2016-01-01

The aim of the present study was to formulate and evaluate the ritonavir-loaded stealth liposomes by using 32 factorial design and intended to delivered by parenteral delivery. Liposomes were prepared by ethanol injection method using 32 factorial designs and characterized for various physicochemical parameters such as drug content, size, zeta potential, entrapment efficiency and in vitro drug release. The optimization process was carried out using desirability and overlay plots. The selected formulation was subjected to PEGylation using 10 % PEG-10000 solution. Stealth liposomes were characterized for the above-mentioned parameters along with surface morphology, Fourier transform infrared spectrophotometer, differential scanning calorimeter, stability and in vivo pharmacokinetic studies in rats. Stealth liposomes showed better result compared to conventional liposomes due to effect of PEG-10000. The in vivo studies revealed that stealth liposomes showed better residence time compared to conventional liposomes and pure drug solution. The conventional liposomes and pure drug showed dose-dependent pharmacokinetics, whereas stealth liposomes showed long circulation half-life compared to conventional liposomes and pure ritonavir solution. The results of statistical analysis showed significance difference as the p value is (<0.05) by one-way ANOVA. The result of the present study revealed that stealth liposomes are promising tool in antiretroviral therapy.

Multi-bit wavelength coding phase-shift-keying optical steganography based on amplified spontaneous emission noise

NASA Astrophysics Data System (ADS)

Wang, Cheng; Wang, Hongxiang; Ji, Yuefeng

2018-01-01

In this paper, a multi-bit wavelength coding phase-shift-keying (PSK) optical steganography method is proposed based on amplified spontaneous emission noise and wavelength selection switch. In this scheme, the assignment codes and the delay length differences provide a large two-dimensional key space. A 2-bit wavelength coding PSK system is simulated to show the efficiency of our proposed method. The simulated results demonstrate that the stealth signal after encoded and modulated is well-hidden in both time and spectral domains, under the public channel and noise existing in the system. Besides, even the principle of this scheme and the existence of stealth channel are known to the eavesdropper, the probability of recovering the stealth data is less than 0.02 if the key is unknown. Thus it can protect the security of stealth channel more effectively. Furthermore, the stealth channel will results in 0.48 dB power penalty to the public channel at 1 × 10-9 bit error rate, and the public channel will have no influence on the receiving of the stealth channel.

Direct trust-based security scheme for RREQ flooding attack in mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Kumar, Sunil; Dutta, Kamlesh

2017-06-01

The routing algorithms in MANETs exhibit distributed and cooperative behaviour which makes them easy target for denial of service (DoS) attacks. RREQ flooding attack is a flooding-type DoS attack in context to Ad hoc On Demand Distance Vector (AODV) routing protocol, where the attacker broadcasts massive amount of bogus Route Request (RREQ) packets to set up the route with the non-existent or existent destination in the network. This paper presents direct trust-based security scheme to detect and mitigate the impact of RREQ flooding attack on the network, in which, every node evaluates the trust degree value of its neighbours through analysing the frequency of RREQ packets originated by them over a short period of time. Taking the node's trust degree value as the input, the proposed scheme is smoothly extended for suppressing the surplus RREQ and bogus RREQ flooding packets at one-hop neighbours during the route discovery process. This scheme distinguishes itself from existing techniques by not directly blocking the service of a normal node due to increased amount of RREQ packets in some unusual conditions. The results obtained throughout the simulation experiments clearly show the feasibility and effectiveness of the proposed defensive scheme.

Geographic Wormhole Detection in Wireless Sensor Networks

PubMed Central

Sookhak, Mehdi; Akhundzada, Adnan; Sookhak, Alireza; Eslaminejad, Mohammadreza; Gani, Abdullah; Khurram Khan, Muhammad; Li, Xiong; Wang, Xiaomin

2015-01-01

Wireless sensor networks (WSNs) are ubiquitous and pervasive, and therefore; highly susceptible to a number of security attacks. Denial of Service (DoS) attack is considered the most dominant and a major threat to WSNs. Moreover, the wormhole attack represents one of the potential forms of the Denial of Service (DoS) attack. Besides, crafting the wormhole attack is comparatively simple; though, its detection is nontrivial. On the contrary, the extant wormhole defense methods need both specialized hardware and strong assumptions to defend against static and dynamic wormhole attack. The ensuing paper introduces a novel scheme to detect wormhole attacks in a geographic routing protocol (DWGRP). The main contribution of this paper is to detect malicious nodes and select the best and the most reliable neighbors based on pairwise key pre-distribution technique and the beacon packet. Moreover, this novel technique is not subject to any specific assumption, requirement, or specialized hardware, such as a precise synchronized clock. The proposed detection method is validated by comparisons with several related techniques in the literature, such as Received Signal Strength (RSS), Authentication of Nodes Scheme (ANS), Wormhole Detection uses Hound Packet (WHOP), and Wormhole Detection with Neighborhood Information (WDI) using the NS-2 simulator. The analysis of the simulations shows promising results with low False Detection Rate (FDR) in the geographic routing protocols. PMID:25602616

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. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

RF Stealth (Or Low Observable) and Counter- RF Stealth Technologies: Implications of Counter- RF Stealth Solutions for Turkish Air Force

DTIC Science & Technology

2009-03-01

Robotics Coating Facility for Low Observable Material Applications...aircraft. After separation, it would fly to around 78,000 ft altitude and self navigate with its internal Doppler guidance system. If desired, it...lossy magnetic material, with 2 cm of soft rubber , were utilized for purposes of absorbing radar energy and reducing IR signature. Moreover, some tail

6-mercaptopurine (6-MP) entrapped stealth liposomes for improvement of leukemic treatment without hepatotoxicity and nephrotoxicity.

PubMed

Umrethia, Manish; Ghosh, Pradip Kumar; Majithya, Rita; Murthy, R S R

2007-03-01

6-mercaptopurine (6-MP) is a purine analogue used in childhood leukemia. Because of the oral bioavailability of 6-MP is low and highly variable, the aim of this study was to develop a new parenteral formulation that can prolong the biological half-life of the drug, improve its therapeutic efficacy, and its associated reduce side effects. Conventional and stealth 6-MP liposomes were prepared by a thin film hydration technique followed by a high-pressure homogenization process and characterized for percent entrapment efficiency (%EE), particle size, and stability in human plasma. Pharmacokinetic, tissue distribution, and biochemical analysis were performed after intravenous (IV) administration of all formulations of 6-MP on rats. The conventional liposomes were found less stable than stealth liposomes in human plasma at 37 degrees C. Stealth liposomes exhibited high peak plasma concentration (C(max)), and long circulating capacity in blood and biological half-life. The uptake of stealth liposomes by the liver and spleen and accumulation in the kidney were significantly less than that of conventional liposomes and the free drug. Serum urea, creatinine, GOT (Glutamic Oxaloacetic Transaminase), and GPT (Glutamic Pyruvic Transaminase) increased significantly in rats given an IV injection of conventional liposomes and the free drug, but not in those administered with the same dose of stealth liposomes. Stealth liposomes may help to increase therapeutic efficacy of 6-MP and to reduce total amount of dose as well as frequency of the dose. It also may reduce the possibility of the risk of toxicity to the liver and kidney generally associated with free 6-MP.

Temporal phase mask encrypted optical steganography carried by amplified spontaneous emission noise.

PubMed

Wu, Ben; Wang, Zhenxing; Shastri, Bhavin J; Chang, Matthew P; Frost, Nicholas A; Prucnal, Paul R

2014-01-13

A temporal phase mask encryption method is proposed and experimentally demonstrated to improve the security of the stealth channel in an optical steganography system. The stealth channel is protected in two levels. In the first level, the data is carried by amplified spontaneous emission (ASE) noise, which cannot be detected in either the time domain or spectral domain. In the second level, even if the eavesdropper suspects the existence of the stealth channel, each data bit is covered by a fast changing phase mask. The phase mask code is always combined with the wide band noise from ASE. Without knowing the right phase mask code to recover the stealth data, the eavesdropper can only receive the noise like signal with randomized phase.

Optical stealth transmission based on super-continuum generation in highly nonlinear fiber over WDM network.

PubMed

Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Chen, Dalei

2015-06-01

In this Letter, the optical stealth transmission carried by super-continuum spectrum optical pulses generated in highly nonlinear fiber is proposed and experimentally demonstrated. In the proposed transmission scheme, super-continuum signals are reshaped in the spectral domain through a wavelength-selective switch and are temporally spread by a chromatic dispersion device to achieve the same noise-like characteristic as the noise in optical networks, so that in both the time domain and the spectral domain, the stealth signals are hidden in public channel. Our experimental results show that compared with existing schemes where stealth channels are carried by amplified spontaneous emission noise, super-continuum signal can increase the transmission performance and robustness.

Self-enforcing Private Inference Control

NASA Astrophysics Data System (ADS)

Yang, Yanjiang; Li, Yingjiu; Weng, Jian; Zhou, Jianying; Bao, Feng

Private inference control enables simultaneous enforcement of inference control and protection of users' query privacy. Private inference control is a useful tool for database applications, especially when users are increasingly concerned about individual privacy nowadays. However, protection of query privacy on top of inference control is a double-edged sword: without letting the database server know the content of user queries, users can easily launch DoS attacks. To assuage DoS attacks in private inference control, we propose the concept of self-enforcing private inference control, whose intuition is to force users to only make inference-free queries by enforcing inference control themselves; otherwise, penalty will inflict upon the violating users.

Stealth and Natural Disasters: Science, Policy and Human Behavior

NASA Astrophysics Data System (ADS)

Kieffer, S. W.

2008-12-01

Geophysicists, earth scientists, and other natural scientists play a key role in studying disasters, and are challenged to convey the science to the public and policy makers (including government and business). I have found it useful to introduce the concept of two general types of disasters to these audiences: natural and stealth. Natural disasters are geological phenomena over which we humans have some, but relatively little, control. Earthquakes, tsunamis, floods and volcanic eruptions are the most familiar examples, but exogenous events such as meteorite impacts, solar flares, and supernovae are also possibly disruptive. Natural disasters typically have an abrupt onset, cause immediate major change, are familiar from the historic record, and get much media and public attention. They cannot be prevented, but preplanning can ameliorate their effects. Natural disasters are increasingly amplified by us (humans), and we are increasingly affected by them due to our expanding presence on the planet. Less familiar disasters are unfolding in the near-term, but they are not happening in the minds of most people. They are approaching us stealthily, and for this reason I propose that we call them stealth disasters. They differ from natural disasters in several important ways: stealth disasters are primarily caused by, or driven by, the interaction of humans with complex cycles of processes on the planet. Examples are: fresh water shortages and contamination, soil degradation and loss, climate changes, ocean degradation. The onset of stealth disasters is incremental rather than abrupt. They may not unfold significantly during the course of one term of political office, but they are unfolding in our lifetime. We as individuals may or may not escape their consequences, but they will affect our children and grandchildren. If humans are familiar with stealth disasters at all, it is from a relatively local experience, e.g., flooding of the Mississippi or the Dust Bowl in the U.S., or their counterparts in other places globally. Knowledge of stealth disasters is not universal at the scale now required for global attention. Pre-planning can allay the impacts of stealth disasters, or possibly even prevent them. It is imperative that a new Congress and new Administration be informed of the need to respond to both the near-term natural disasters, and to immediately institute thoughtful planning to ally or prevent the stealth disasters.

Improved pharmacokinetics and reduced toxicity of brucine after encapsulation into stealth liposomes: role of phosphatidylcholine

PubMed Central

Chen, Jun; Yan, Guo-jun; Hu, Rong-rong; Gu, Qian-wen; Chen, Ming-lei; Gu, Wei; Chen, Zhi-peng; Cai, Bao-chang

2012-01-01

Objective: Brucine was encapsulated into stealth liposomes using the ammonium sulfate gradient method to improve therapeutic index. Materials and methods: Four brucine stealth liposomal formulations were prepared, which were made from different phosphatidylcholines (PCs) with different phase transition temperatures (Tm). The PCs used were soy phosphatidylcholine (SPC), dipalmitoyl phosphatidylcholine (DPPC), hydrogenated soy phosphatidylcholine (HSPC), and distearoyl phosphatidylcholine (DSPC). The stabilities, pharmacokinetics, and toxicities of these liposomal formulations were evaluated and compared. Results: Size, zeta potential, and entrapment efficiency of brucine-loaded stealth liposomes (BSL) were not influenced by PC composition. In vitro release studies revealed that drug release rate increased with decreased Tm of PCs, especially with the presence of rat plasma. After intravenous administration, the area under the curve (AUC) values of BSL-SPC, BSL-DPPC, BSL-HSPC, and BSL-DSPC in plasma were 7.71, 9.24, 53.83, and 56.83-fold as large as that of free brucine, respectively. The LD50 values of brucine solution, BSL-SPC, BSL-DPPC, BSL-HSPC, and BSL-DSPC following intravenous injection were 13.17, 37.30, 37.69, 51.18, and 52.86 mg/kg, respectively. It was found in calcein retention experiments that the order of calcein retention in rat plasma was SPC < DPPC << HSPC < DSPC stealth liposomes. Conclusion: PC composition could exert significant influence on the stabilities, pharmacokinetics, and toxicities of brucine-loaded stealth liposomes. DSPC or HSPC with Tm above 50°C should be used to prepare the stealth liposomal formulation for the intravenous delivery of brucine. However, it was found in the present paper that the pharmacokinetics and toxicity of BSL were not influenced by the PC composition when the Tm of the PC was in the range of −20°C to 41°C. PMID:22904620

Research on a Denial of Service (DoS) Detection System Based on Global Interdependent Behaviors in a Sensor Network Environment

PubMed Central

Song, Jae-gu; Jung, Sungmo; Kim, Jong Hyun; Seo, Dong Il; Kim, Seoksoo

2010-01-01

This research suggests a Denial of Service (DoS) detection method based on the collection of interdependent behavior data in a sensor network environment. In order to collect the interdependent behavior data, we use a base station to analyze traffic and behaviors among nodes and introduce methods of detecting changes in the environment with precursor symptoms. The study presents a DoS Detection System based on Global Interdependent Behaviors and shows the result of detecting a sensor carrying out DoS attacks through the test-bed. PMID:22163475

Future Jet Technologies, Part C

NASA Astrophysics Data System (ADS)

Gal-Or, Benjamin

2013-06-01

This updated, PART C REVIEW, covers the dangerous global spread of JS-stealth, drone technology [1-91], canard-free, stealth, new agile drones and the highly debated, 480 billion F-35 International Program as reported on March 13, 2013 to the U.S. Congress [92]. Due to serious design issues, spiraling high costs and years in delays, alternatives are analyzed here, depicted and proposed, mainly from the propulsion-design point of view. These include fleets of low-cost, stealth, jet-steered-drones mixed with non-stealthy, low-cost, ready-to-be-delivered, U.S. or European or Russian fighter aircraft. Can a few F-35s win against large fleets of stealth agile drones? To understand the dangers and critical issues involved, the author's own, past classified information is partly disclosed, while resorting to images in Figs. 2(a) and 2(b) taken from his book [2] and from Wikipedia, the "Free Encyclopedia", in all other images.

Bactericidal Dendritic Polycation Cloaked with Stealth Material via Lipase-Sensitive Intersegment Acquires Neutral Surface Charge without Losing Membrane-Disruptive Activity.

PubMed

Xu, Lulu; He, Chen; Hui, Liwei; Xie, Yuntao; Li, Jia-Min; He, Wei-Dong; Yang, Lihua

2015-12-23

Net cationicity of membrane-disruptive antimicrobials is necessary for their activity but may elicit immune attack when administered intravenously. By cloaking a dendritic polycation (G2) with poly(caprolactone-b-ethylene glycol) (PCL-b-PEG), we obtain a nanoparticle antimicrobial, G2-g-(PCL-b-PEG), which exhibits neutral surface charge but kills >99.9% of inoculated bacterial cells at ≤8 μg/mL. The observed activity may be attributed PCL's responsive degradation by bacterial lipase and the consequent exposure of the membrane-disruptive, bactericidal G2 core. Moreover, G2-g-(PCL-b-PEG) exhibits good colloidal stability in the presence of serum and insignificant hemolytic toxicity even at ≥2048 μg/mL. suggesting good blood compatibility required for intravenous administration.

On securing wireless sensor network--novel authentication scheme against DOS attacks.

PubMed

Raja, K Nirmal; Beno, M Marsaline

2014-10-01

Wireless sensor networks are generally deployed for collecting data from various environments. Several applications specific sensor network cryptography algorithms have been proposed in research. However WSN's has many constrictions, including low computation capability, less memory, limited energy resources, vulnerability to physical capture, which enforce unique security challenges needs to make a lot of improvements. This paper presents a novel security mechanism and algorithm for wireless sensor network security and also an application of this algorithm. The proposed scheme is given to strong authentication against Denial of Service Attacks (DOS). The scheme is simulated using network simulator2 (NS2). Then this scheme is analyzed based on the network packet delivery ratio and found that throughput has improved.

Design and characterization of one-dimensional photonic crystals based on ZnS/Ge for infrared-visible compatible stealth applications

NASA Astrophysics Data System (ADS)

Qi, Dong; Wang, Xian; Cheng, Yongzhi; Gong, Rongzhou; Li, Bowen

2016-12-01

One-dimensional photonic crystals (1DPCs) based on ZnS/Ge for compatible stealth of infrared and visible were firstly proposed theoretically and investigated experimentally. Owing to the equal inclination interference, the designed 1DPCs structure can be fabricated with a certain color corresponding to the different responded wavelength. In addition, the average emissivity of the proposed structure can reach as low as 0.054 at infrared atmosphere window of 3-5 μm. The as-prepared structure indicates that it is feasible for 1DPC to achieve infrared-visible compatible stealth.

How Low Can You Go? Low Densities of Poly(ethylene glycol) Surfactants Attract Stealth Proteins.

PubMed

Seneca, Senne; Simon, Johanna; Weber, Claudia; Ghazaryan, Arthur; Ethirajan, Anitha; Mailaender, Volker; Morsbach, Svenja; Landfester, Katharina

2018-06-25

It is now well-established that the surface chemistry and "stealth" surface functionalities such as poly(ethylene glycol) (PEG) chains of nanocarriers play an important role to decrease unspecific protein adsorption of opsonizing proteins, to increase the enrichment of specific stealth proteins, and to prolong the circulation times of the nanocarriers. At the same time, PEG chains are used to provide colloidal stability for the nanoparticles. However, it is not clear how the chain length and density influence the unspecific and specific protein adsorption keeping at the same time the stability of the nanoparticles in a biological environment. Therefore, this study aims at characterizing the protein adsorption patterns depending on PEG chain length and density to define limits for the amount of PEG needed for a stealth effect by selective protein adsorption as well as colloidal stability during cell experiments. PEG chains are introduced using the PEGylated Lutensol AT surfactants, which allow easy modification of the nanoparticle surface. These findings indicate that a specific enrichment of stealth proteins already occurs at low PEG concentrations; for the decrease of unspecific protein adsorption and finally the colloidal stability a full surface coverage is advised. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Goldstone/VLA 3.5cm Mars Radar Observations - "Stealths" and South Polar Regions

NASA Astrophysics Data System (ADS)

Butler, Bryan; Chizek, M. R.; Slade, M. A.; Haldemann, A. F.; Muhleman, D. O.; Mao, T. F.

2006-09-01

The opposition of Mars in 2003 provided a fantastic opportunity to use the combined Goldstone/VLA radar to probe the surface with the highest resolution ever obtained on Mars with that instrument (as good as 70 km). Observations were made on August 11, 19, 28, and September 8. Details of data reduction and analysis of the radar echoes from the volcanic regions of the planet are presented in a companion paper in these proceedings (Chizek et al.). We will present results related to "Stealth" (and other radar-dark regions of the planet, including the Argyre and Hellas Planitiae, and a region to the west of the Elysium Mons caldera), and the south polar residual and seasonal ice caps. The size, shape, and reflectivity characteristics of Stealth and "mega-Stealth" (Edgett et al. 1997) are reaffirmed, with a better viewing geometry of the western extent of the feature than had been obtained previously. It had been speculated previously that Hellas Planitia should also be radar dark - this is confirmed by our imaging, though the reflectivity is not as low as for Stealth. We find a new radar dark area to the west of Elysium Mons, which is likely an ash fall from that volcano (similar to the relationship between Stealth and the Tharsis volcanoes). The south polar residual ice cap is a very bright reflector, as seen previously, but we now also see a very bright reflection from the seasonal cap, not seen previously. The cap is not uniformly bright, however, and the extent of the bright reflection does not correspond to that expected from the retreat of the cap as measured either from albedo or thermal emission characteristics. The NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Cryo-electron tomography investigation of serum albumin-camouflaged tobacco mosaic virus nanoparticles.

PubMed

Gulati, Neetu M; Pitek, Andrzej S; Steinmetz, Nicole F; Stewart, Phoebe L

2017-03-09

Nanoparticles offer great potential in drug delivery and imaging, but shielding strategies are necessary to increase circulation time and performance. Structure-function studies are required to define the design rules to achieve effective shielding. With several formulations reaching clinical testing and approval, the ability to assess and detail nanoparticle formulations at the single particle level is becoming increasingly important. To address this need, we use cryo-electron tomography (cryo-ET) to investigate stealth-coated nanoparticles. As a model system, we studied the soft matter nanotubes formed by tobacco mosaic virus (TMV) coated with human serum albumin (SA) stealth proteins. Cryo-ET and subtomogram averaging allow for visualization of individual SA molecules and determination of their orientations relative to the TMV surface, and also for measurement of the surface coverage provided by added stealth proteins. This information fills a critical gap in the understanding of the structural morphology of stealth-coated nanoparticles, and therefore cryo-ET may play an important role in guiding the development of future nanoparticle-based therapeutics.

Measuring Problem Solving Skills in "Portal 2"

ERIC Educational Resources Information Center

Shute, Valerie J.; Wang, Lubin

2013-01-01

This paper examines possible improvement to problem solving skills as a function of playing the video game "Portal 2." Stealth assessment is used in the game to evaluate students' problem solving abilities--specifically basic and flexible rule application. The stealth assessment measures will be validated against commonly accepted…

Stealth Aircraft Technology. (Latest Citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1995-01-01

The bibliography contains citations concerning design, manufacture, and history of aircraft incorporating stealth technology. Citations focus on construction materials, testing, aircraft performance, and technology assessment. Fighter aircraft, bombers, missiles, and helicopters represent coverage. (Contains 50-250 citations and includes a subject term index and title list.)

Stealth Biocompatible Si-Based Nanoparticles for Biomedical Applications

PubMed Central

Chaix, Arnaud; Gary-Bobo, Magali; Angeletti, Bernard; Masion, Armand; Da Silva, Afitz; Daurat, Morgane; Lichon, Laure; Garcia, Marcel; Morère, Alain; El Cheikh, Khaled; Durand, Jean-Olivier; Cunin, Frédérique; Auffan, Mélanie

2017-01-01

A challenge regarding the design of nanocarriers for drug delivery is to prevent their recognition by the immune system. To improve the blood residence time and prevent their capture by organs, nanoparticles can be designed with stealth properties using polymeric coating. In this study, we focused on the influence of surface modification with polyethylene glycol and/or mannose on the stealth behavior of porous silicon nanoparticles (pSiNP, ~200 nm). In vivo biodistribution of pSiNPs formulations were evaluated in mice 5 h after intravenous injection. Results indicated that the distribution in the organs was surface functionalization-dependent. Pristine pSiNPs and PEGylated pSiNPs were distributed mainly in the liver and spleen, while mannose-functionalized pSiNPs escaped capture by the spleen, and had higher blood retention. The most efficient stealth behavior was observed with PEGylated pSiNPs anchored with mannose that were the most excreted in urine at 5 h. The biodegradation kinetics evaluated in vitro were in agreement with these in vivo observations. The biocompatibility of the pristine and functionalized pSiNPs was confirmed in vitro on human cell lines and in vivo by cytotoxic and systemic inflammation investigations, respectively. With their biocompatibility, biodegradability, and stealth properties, the pSiNPs functionalized with mannose and PEG show promising potential for biomedical applications. PMID:28946628

Development of an inverse distance weighted active infrared stealth scheme using the repulsive particle swarm optimization algorithm.

PubMed

Han, Kuk-Il; Kim, Do-Hwi; Choi, Jun-Hyuk; Kim, Tae-Kuk

2018-04-20

Treatments for detection by infrared (IR) signals are higher than for other signals such as radar or sonar because an object detected by the IR sensor cannot easily recognize its detection status. Recently, research for actively reducing IR signal has been conducted to control the IR signal by adjusting the surface temperature of the object. In this paper, we propose an active IR stealth algorithm to synchronize IR signals from the object and the background around the object. The proposed method includes the repulsive particle swarm optimization statistical optimization algorithm to estimate the IR stealth surface temperature, which will result in a synchronization between the IR signals from the object and the surrounding background by setting the inverse distance weighted contrast radiant intensity (CRI) equal to zero. We tested the IR stealth performance in mid wavelength infrared (MWIR) and long wavelength infrared (LWIR) bands for a test plate located at three different positions on a forest scene to verify the proposed method. Our results show that the inverse distance weighted active IR stealth technique proposed in this study is proved to be an effective method for reducing the contrast radiant intensity between the object and background up to 32% as compared to the previous method using the CRI determined as the simple signal difference between the object and the background.

How sailfish use their bills to capture schooling prey.

PubMed

Domenici, P; Wilson, A D M; Kurvers, R H J M; Marras, S; Herbert-Read, J E; Steffensen, J F; Krause, S; Viblanc, P E; Couillaud, P; Krause, J

2014-06-07

The istiophorid family of billfishes is characterized by an extended rostrum or 'bill'. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to feed on prey. Here, we present the first unequivocal evidence of how the bill is used by Atlantic sailfish (Istiophorus albicans) to attack schooling sardines in the open ocean. Using high-speed video-analysis, we show that (i) sailfish manage to insert their bill into sardine schools without eliciting an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey.

Taking the Steam off Pressure Groups.

ERIC Educational Resources Information Center

Ledell, Marjorie A.

1993-01-01

School administrators must speak out when single-issue or "stealth" groups threaten to take over a school board. Administrators can help ensure that election campaigns stimulate community debate, discussion, and consensus about educational directions. They must know how to remove the cover from stealth candidates, respond to the public,…

Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen

PubMed Central

Radolf, Justin D.; Deka, Ranjit K.; Anand, Arvind; Šmajs, David; Norgard, Michael V.; Yang, X. Frank

2016-01-01

The last two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The syphilis spirochete’s well-recognized capacity for early dissemination and immune evasion has earned it the designation ‘the stealth pathogen’. Despite the many hurdles to studying syphilis pathogenesis, most notably the inability to culture and to genetically manipulate T. pallidum, in recent years, considerable progress has been made in elucidating the structural, physiologic, and regulatory facets of stealth pathogenicity. In this Review, we integrate this eclectic body of information to garner fresh insights into the highly successful parasitic lifestyles of the syphilis spirochete and related pathogenic treponemes. PMID:27721440

Embedding Quantitative Methods by Stealth in Political Science: Developing a Pedagogy for Psephology

ERIC Educational Resources Information Center

Gunn, Andrew

2017-01-01

Student evaluations of quantitative methods courses in political science often reveal they are characterised by aversion, alienation and anxiety. As a solution to this problem, this paper describes a pedagogic research project with the aim of embedding quantitative methods by stealth into the first-year undergraduate curriculum. This paper…

Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing transverse momentum in pp collisions at 8 TeV

NASA Astrophysics Data System (ADS)

Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Daci, N.; Heracleous, N.; Keaveney, J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Randle-conde, A.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Dildick, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Dos Reis Martins, T.; Molina, J.; Mora Herrera, C.; Pol, M. E.; Rebello Teles, P.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santaolalla, J.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Hadjiiska, R.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Tao, J.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Ellithi Kamel, A.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Busson, P.; Chapon, E.; Charlot, C.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Bernet, C.; Boudoul, G.; Bouvier, E.; Brochet, S.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Xiao, H.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Bontenackels, M.; Edelhoff, M.; Feld, L.; Heister, A.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Preuten, M.; Raupach, F.; Sammet, J.; Schael, S.; Schulte, J. F.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Erdmann, M.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Knutzen, S.; Kreuzer, P.; Merschmeyer, M.; Meyer, A.; Millet, P.; Olschewski, M.; Padeken, K.; Papacz, P.; Reithler, H.; Schmitz, S. A.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Weber, M.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Haj Ahmad, W.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Künsken, A.; Lingemann, J.; Nowack, A.; Nugent, I. M.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Asin, I.; Bartosik, N.; Behr, J.; Behrens, U.; Bell, A. J.; Bethani, A.; Borras, K.; Burgmeier, A.; Cakir, A.; Calligaris, L.; Campbell, A.; Choudhury, S.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Dooling, S.; Dorland, T.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Flucke, G.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Gunnellini, P.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Kasemann, M.; Katsas, P.; Kieseler, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Lutz, B.; Mankel, R.; Marfin, I.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Ribeiro Cipriano, P. M.; Roland, B.; Ron, E.; Sahin, M. Ö.; Salfeld-Nebgen, J.; Saxena, P.; Schoerner-Sadenius, T.; Schröder, M.; Seitz, C.; Spannagel, S.; Vargas Trevino, A. D. R.; Walsh, R.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Erfle, J.; Garutti, E.; Goebel, K.; Görner, M.; Haller, J.; Hoffmann, M.; Höing, R. S.; Junkes, A.; Kirschenmann, H.; Klanner, R.; Kogler, R.; Lange, J.; Lapsien, T.; Lenz, T.; Marchesini, I.; Ott, J.; Peiffer, T.; Perieanu, A.; Pietsch, N.; Poehlsen, J.; Poehlsen, T.; Rathjens, D.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schmidt, A.; Seidel, M.; Sola, V.; Stadie, H.; Steinbrück, G.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Barth, C.; Baus, C.; Berger, J.; Böser, C.; Butz, E.; Chwalek, T.; De Boer, W.; Descroix, A.; Dierlamm, A.; Feindt, M.; Frensch, F.; Giffels, M.; Gilbert, A.; Hartmann, F.; Hauth, T.; Husemann, U.; Katkov, I.; Kornmayer, A.; Lobelle Pardo, P.; Mozer, M. U.; Müller, T.; Müller, Th.; Nürnberg, A.; Quast, G.; Rabbertz, K.; Röcker, S.; Simonis, H. J.; Stober, F. M.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weiler, T.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Markou, A.; Markou, C.; Psallidas, A.; Topsis-Giotis, I.; Agapitos, A.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Stiliaris, E.; Aslanoglou, X.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Bencze, G.; Hajdu, C.; Hidas, P.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Molnar, J.; Palinkas, J.; Szillasi, Z.; Makovec, A.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Swain, S. K.; Beri, S. B.; Bhatnagar, V.; Gupta, R.; Bhawandeep, U.; Kalsi, A. K.; Kaur, M.; Kumar, R.; Mittal, M.; Nishu, N.; Singh, J. B.; Kumar, Ashok; Kumar, Arun; Ahuja, S.; Bhardwaj, A.; Choudhary, B. C.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, V.; Banerjee, S.; Bhattacharya, S.; Chatterjee, K.; Dutta, S.; Gomber, B.; Jain, Sa.; Jain, Sh.; Khurana, R.; Modak, A.; Mukherjee, S.; Roy, D.; Sarkar, S.; Sharan, M.; Abdulsalam, A.; Dutta, D.; Kumar, V.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Banerjee, S.; Bhowmik, S.; Chatterjee, R. M.; Dewanjee, R. K.; Dugad, S.; Ganguly, S.; Ghosh, S.; Guchait, M.; Gurtu, A.; Kole, G.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Mohanty, G. B.; Parida, B.; Sudhakar, K.; Wickramage, N.; Bakhshiansohi, H.; Behnamian, H.; Etesami, S. M.; Fahim, A.; Goldouzian, R.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Chhibra, S. S.; Colaleo, A.; Creanza, D.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Selvaggi, G.; Sharma, A.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. 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T.; Montecassiano, F.; Passaseo, M.; Pazzini, J.; Pegoraro, M.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Tosi, M.; Zotto, P.; Zucchetta, A.; Zumerle, G.; Gabusi, M.; Ratti, S. P.; Re, V.; Riccardi, C.; Salvini, P.; Vitulo, P.; Biasini, M.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Mantovani, G.; Menichelli, M.; Saha, A.; Santocchia, A.; Spiezia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Broccolo, G.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Fiori, F.; Foà, L.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Moon, C. S.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Serban, A. T.; Spagnolo, P.; Squillacioti, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Vernieri, C.; Barone, L.; Cavallari, F.; D'imperio, G.; Del Re, D.; Diemoz, M.; Jorda, C.; Longo, E.; Margaroli, F.; Meridiani, P.; Micheli, F.; Organtini, G.; Paramatti, R.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Soffi, L.; Traczyk, P.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bellan, R.; Biino, C.; Cartiglia, N.; Casasso, S.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Musich, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Potenza, A.; Romero, A.; Ruspa, M.; Sacchi, R.; Solano, A.; Staiano, A.; Tamponi, U.; Belforte, S.; Candelise, V.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Gobbo, B.; La Licata, C.; Marone, M.; Schizzi, A.; Umer, T.; Zanetti, A.; Chang, S.; Kropivnitskaya, A.; Nam, S. K.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Kong, D. J.; Lee, S.; Oh, Y. D.; Park, H.; Sakharov, A.; Son, D. C.; Kim, T. J.; Ryu, M. S.; Kim, J. Y.; Moon, D. H.; Song, S.; Choi, S.; Gyun, D.; Hong, B.; Jo, M.; Kim, H.; Kim, Y.; Lee, B.; Lee, K. S.; Park, S. K.; Roh, Y.; Yoo, H. D.; Choi, M.; Kim, J. H.; Park, I. C.; Ryu, G.; Choi, Y.; Choi, Y. K.; Goh, J.; Kim, D.; Kwon, E.; Lee, J.; Yu, I.; Juodagalvis, A.; Komaragiri, J. R.; Md Ali, M. A. B.; Casimiro Linares, E.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-de La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Vazquez Valencia, F.; Pedraza, I.; Salazar Ibarguen, H. A.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Reucroft, S.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Khurshid, T.; Shoaib, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Brona, G.; Bunkowski, K.; Cwiok, M.; Dominik, W.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Bargassa, P.; Beirão Da Cruz E Silva, C.; Faccioli, P.; Ferreira Parracho, P. G.; Gallinaro, M.; Lloret Iglesias, L.; Nguyen, F.; Rodrigues Antunes, J.; Seixas, J.; Varela, J.; Vischia, P.; Afanasiev, S.; Bunin, P.; Gavrilenko, M.; Golutvin, I.; Gorbunov, I.; Kamenev, A.; Karjavin, V.; Konoplyanikov, V.; Lanev, A.; Malakhov, A.; Matveev, V.; Moisenz, P.; Palichik, V.; Perelygin, V.; Shmatov, S.; Skatchkov, N.; Smirnov, V.; Zarubin, A.; Golovtsov, V.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Levchenko, P.; Murzin, V.; Oreshkin, V.; Smirnov, I.; Sulimov, V.; Uvarov, L.; Vavilov, S.; Vorobyev, A.; Vorobyev, An.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Semenov, S.; Spiridonov, A.; Stolin, V.; Vlasov, E.; Zhokin, A.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Mesyats, G.; Rusakov, S. V.; Vinogradov, A.; Belyaev, A.; Boos, E.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Klyukhin, V.; Kodolova, O.; Lokhtin, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Tourtchanovitch, L.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Ekmedzic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Battilana, C.; Calvo, E.; Cerrada, M.; Chamizo Llatas, M.; Colino, N.; De La Cruz, B.; Delgado Peris, A.; Domínguez Vázquez, D.; Escalante Del Valle, A.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Navarro De Martino, E.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; Albajar, C.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Brun, H.; Cuevas, J.; Fernandez Menendez, J.; Folgueras, S.; Gonzalez Caballero, I.; Brochero Cifuentes, J. A.; Cabrillo, I. J.; Calderon, A.; Duarte Campderros, J.; Fernandez, M.; Gomez, G.; Graziano, A.; Lopez Virto, A.; Marco, J.; Marco, R.; Martinez Rivero, C.; Matorras, F.; Munoz Sanchez, F. J.; Piedra Gomez, J.; Rodrigo, T.; Rodríguez-Marrero, A. Y.; Ruiz-Jimeno, A.; Scodellaro, L.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Auzinger, G.; Bachtis, M.; Baillon, P.; Ball, A. H.; Barney, D.; Benaglia, A.; Bendavid, J.; Benhabib, L.; Benitez, J. F.; Bloch, P.; Bocci, A.; Bonato, A.; Bondu, O.; Botta, C.; Breuker, H.; Camporesi, T.; Cerminara, G.; Colafranceschi, S.; D'Alfonso, M.; d'Enterria, D.; Dabrowski, A.; David, A.; De Guio, F.; De Roeck, A.; De Visscher, S.; Di Marco, E.; Dobson, M.; Dordevic, M.; Dorney, B.; Dupont-Sagorin, N.; Elliott-Peisert, A.; Franzoni, G.; Funk, W.; Gigi, D.; Gill, K.; Giordano, D.; Girone, M.; Glege, F.; Guida, R.; Gundacker, S.; Guthoff, M.; Hammer, J.; Hansen, M.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kousouris, K.; Krajczar, K.; Lecoq, P.; Lourenço, C.; Magini, N.; Malgeri, L.; Mannelli, M.; Marrouche, J.; Masetti, L.; Meijers, F.; Mersi, S.; Meschi, E.; Moortgat, F.; Morovic, S.; Mulders, M.; Orsini, L.; Pape, L.; Perez, E.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pimiä, M.; Piparo, D.; Plagge, M.; Racz, A.; Rolandi, G.; Rovere, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Sharma, A.; Siegrist, P.; Silva, P.; Simon, M.; Sphicas, P.; Spiga, D.; Steggemann, J.; Stieger, B.; Stoye, M.; Takahashi, Y.; Treille, D.; Tsirou, A.; Veres, G. I.; Wardle, N.; Wöhri, H. K.; Wollny, H.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Renker, D.; Rohe, T.; Bachmair, F.; Bäni, L.; Bianchini, L.; Buchmann, M. A.; Casal, B.; Chanon, N.; Dissertori, G.; Dittmar, M.; Donegà, M.; Dünser, M.; Eller, P.; Grab, C.; Hits, D.; Hoss, J.; Lustermann, W.; Mangano, B.; Marini, A. C.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meister, D.; Mohr, N.; Musella, P.; Nägeli, C.; Nessi-Tedaldi, F.; Pandolfi, F.; Pauss, F.; Perrozzi, L.; Peruzzi, M.; Quittnat, M.; Rebane, L.; Rossini, M.; Starodumov, A.; Takahashi, M.; Theofilatos, K.; Wallny, R.; Weber, H. A.; Amsler, C.; Canelli, M. F.; Chiochia, V.; De Cosa, A.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Lange, C.; Millan Mejias, B.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Ronga, F. J.; Taroni, S.; Verzetti, M.; Yang, Y.; Cardaci, M.; Chen, K. H.; Ferro, C.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Volpe, R.; Yu, S. S.; Chang, P.; Chang, Y. H.; Chao, Y.; Chen, K. F.; Chen, P. H.; Dietz, C.; Grundler, U.; Hou, W.-S.; Liu, Y. F.; Lu, R.-S.; Petrakou, E.; Tzeng, Y. M.; Wilken, R.; Asavapibhop, B.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Bakirci, M. N.; Cerci, S.; Dozen, C.; Dumanoglu, I.; Eskut, E.; Girgis, S.; Gokbulut, G.; Guler, Y.; Gurpinar, E.; Hos, I.; Kangal, E. E.; Kayis Topaksu, A.; Onengut, G.; Ozdemir, K.; Ozturk, S.; Polatoz, A.; Sunar Cerci, D.; Tali, B.; Topakli, H.; Vergili, M.; Zorbilmez, C.; Akin, I. V.; Bilin, B.; Bilmis, S.; Gamsizkan, H.; Isildak, B.; Karapinar, G.; Ocalan, K.; Sekmen, S.; Surat, U. E.; Yalvac, M.; Zeyrek, M.; Albayrak, E. A.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, T.; Cankocak, K.; Vardarlı, F. I.; Levchuk, L.; Sorokin, P.; Brooke, J. J.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Meng, Z.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; Seif El Nasr-storey, S.; Senkin, S.; Smith, V. J.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Williams, T.; Womersley, W. J.; Worm, S. D.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Burton, D.; Colling, D.; Cripps, N.; Dauncey, P.; Davies, G.; Della Negra, M.; Dunne, P.; Elwood, A.; Ferguson, W.; Fulcher, J.; Futyan, D.; Hall, G.; Iles, G.; Jarvis, M.; Karapostoli, G.; Kenzie, M.; Lane, R.; Lucas, R.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mathias, B.; Nash, J.; Nikitenko, A.; Pela, J.; Pesaresi, M.; Petridis, K.; Raymond, D. M.; Rogerson, S.; Rose, A.; Seez, C.; Sharp, P.; Tapper, A.; Vazquez Acosta, M.; Virdee, T.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leggat, D.; Leslie, D.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Dittmann, J.; Hatakeyama, K.; Kasmi, A.; Liu, H.; Scarborough, T.; Wu, Z.; Charaf, O.; Cooper, S. I.; Henderson, C.; Rumerio, P.; Avetisyan, A.; Bose, T.; Fantasia, C.; Lawson, P.; Richardson, C.; Rohlf, J.; St. John, J.; Sulak, L.; Alimena, J.; Berry, E.; Bhattacharya, S.; Christopher, G.; Cutts, D.; Demiragli, Z.; Dhingra, N.; Ferapontov, A.; Garabedian, A.; Heintz, U.; Kukartsev, G.; Laird, E.; Landsberg, G.; Luk, M.; Narain, M.; Segala, M.; Sinthuprasith, T.; Speer, T.; Swanson, J.; Breedon, R.; Breto, G.; Calderon De La Barca Sanchez, M.; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Gardner, M.; Ko, W.; Lander, R.; Mulhearn, M.; Pellett, D.; Pilot, J.; Ricci-Tam, F.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Wilbur, S.; Yohay, R.; Cousins, R.; Everaerts, P.; Farrell, C.; Hauser, J.; Ignatenko, M.; Rakness, G.; Takasugi, E.; Valuev, V.; Weber, M.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Hanson, G.; Heilman, J.; Ivova Rikova, M.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Luthra, A.; Malberti, M.; Olmedo Negrete, M.; Shrinivas, A.; Sumowidagdo, S.; Wimpenny, S.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; D'Agnolo, R. T.; Holzner, A.; Kelley, R.; Klein, D.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Palmer, C.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Tu, Y.; Vartak, A.; Welke, C.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Barge, D.; Bradmiller-Feld, J.; Campagnari, C.; Danielson, T.; Dishaw, A.; Dutta, V.; Flowers, K.; Franco Sevilla, M.; Geffert, P.; George, C.; Golf, F.; Gouskos, L.; Incandela, J.; Justus, C.; Mccoll, N.; Mullin, S. D.; Richman, J.; Stuart, D.; To, W.; West, C.; Yoo, J.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Duarte, J.; Mott, A.; Newman, H. B.; Pena, C.; Pierini, M.; Spiropulu, M.; Vlimant, J. R.; Wilkinson, R.; Xie, S.; Zhu, R. Y.; Azzolini, V.; Calamba, A.; Carlson, B.; Ferguson, T.; Iiyama, Y.; Paulini, M.; Russ, J.; Vogel, H.; Vorobiev, I.; Cumalat, J. P.; Ford, W. T.; Gaz, A.; Krohn, M.; Luiggi Lopez, E.; Nauenberg, U.; Smith, J. G.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chatterjee, A.; Chaves, J.; Chu, J.; Dittmer, S.; Eggert, N.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Ryd, A.; Salvati, E.; Skinnari, L.; Sun, W.; Teo, W. D.; Thom, J.; Thompson, J.; Tucker, J.; Weng, Y.; Winstrom, L.; Wittich, P.; Winn, D.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hanlon, J.; Hare, D.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Kwan, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Martinez Outschoorn, V. I.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mishra, K.; Mrenna, S.; Nahn, S.; Newman-Holmes, C.; O'Dell, V.; Prokofyev, O.; Sexton-Kennedy, E.; Sharma, S.; Soha, A.; Spalding, W. J.; Spiegel, L.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vidal, R.; Whitbeck, A.; Whitmore, J.; Yang, F.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Carver, M.; Curry, D.; Das, S.; De Gruttola, M.; Di Giovanni, G. P.; Field, R. D.; Fisher, M.; Furic, I. K.; Hugon, J.; Konigsberg, J.; Korytov, A.; Kypreos, T.; Low, J. F.; Matchev, K.; Mei, H.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rinkevicius, A.; Shchutska, L.; Snowball, M.; Sperka, D.; Yelton, J.; Zakaria, M.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Adams, J. R.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Baarmand, M. M.; Hohlmann, M.; Kalakhety, H.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, I. D.; Silkworth, C.; Turner, P.; Varelas, N.; Bilki, B.; Clarida, W.; Dilsiz, K.; Haytmyradov, M.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Rahmat, R.; Sen, S.; Tan, P.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Barnett, B. A.; Blumenfeld, B.; Bolognesi, S.; Fehling, D.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Swartz, M.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Gray, J.; Kenny, R. P., III; Majumder, D.; Malek, M.; Murray, M.; Noonan, D.; Sanders, S.; Sekaric, J.; Stringer, R.; Wang, Q.; Wood, J. S.; Chakaberia, I.; Ivanov, A.; Kaadze, K.; Khalil, S.; Makouski, M.; Maravin, Y.; Saini, L. K.; Skhirtladze, N.; Svintradze, I.; Gronberg, J.; Lange, D.; Rebassoo, F.; Wright, D.; Baden, A.; Belloni, A.; Calvert, B.; Eno, S. C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Lu, Y.; Mignerey, A. C.; Pedro, K.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Busza, W.; Cali, I. A.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Klute, M.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Stephans, G. S. F.; Sumorok, K.; Velicanu, D.; Veverka, J.; Wyslouch, B.; Yang, M.; Zanetti, M.; Zhukova, V.; Dahmes, B.; Gude, A.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Mans, J.; Nourbakhsh, S.; Pastika, N.; Rusack, R.; Singovsky, A.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Gonzalez Suarez, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Meier, F.; Ratnikov, F.; Snow, G. R.; Zvada, M.; Dolen, J.; Godshalk, A.; Iashvili, I.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Trocino, D.; Wang, R.-J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Velasco, M.; Won, S.; Brinkerhoff, A.; Chan, K. M.; Drozdetskiy, A.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Lynch, S.; Marinelli, N.; Musienko, Y.; Pearson, T.; Planer, M.; Ruchti, R.; Smith, G.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Luo, W.; Puigh, D.; Rodenburg, M.; Winer, B. L.; Wolfe, H.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Brownson, E.; Malik, S.; Mendez, H.; Ramirez Vargas, J. E.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; De Mattia, M.; Gutay, L.; Hu, Z.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Leonardo, N.; Miller, D. H.; Neumeister, N.; Primavera, F.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Zablocki, J.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Ecklund, K. M.; Geurts, F. J. M.; Li, W.; Michlin, B.; Padley, B. P.; Redjimi, R.; Roberts, J.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Hindrichs, O.; Khukhunaishvili, A.; Korjenevski, S.; Petrillo, G.; Vishnevskiy, D.; Ciesielski, R.; Demortier, L.; Goulianos, K.; Mesropian, C.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Kaplan, S.; Lath, A.; Panwalkar, S.; Park, M.; Patel, R.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Khotilovich, V.; Krutelyov, V.; Montalvo, R.; Osipenkov, I.; Pakhotin, Y.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Suarez, I.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kovitanggoon, K.; Kunori, S.; Lee, S. W.; Libeiro, T.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sharma, M.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wood, J.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Dasu, S.; Dodd, L.; Duric, S.; Friis, E.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Lazaridis, C.; Levine, A.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Sarangi, T.; Savin, A.; Smith, W. H.; Taylor, D.; Vuosalo, C.; Woods, N.

2015-04-01

The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton-proton collisions collected at a center-of-mass energy √{ s} = 8 TeV with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 fb-1. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in which SUSY is approximately conserved. The data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation, and the results are used to set limits on squark pair production in the stealth SUSY framework.

Infrared radiation and stealth characteristics prediction for supersonic aircraft with uncertainty

NASA Astrophysics Data System (ADS)

Pan, Xiaoying; Wang, Xiaojun; Wang, Ruixing; Wang, Lei

2015-11-01

The infrared radiation (IR) intensity is generally used to embody the stealth characteristics of a supersonic aircraft, which directly affects its survivability in warfare. Under such circumstances, the research on IR signature as an important branch of stealth technology is significant to overcome this threat for survivability enhancement. Considering the existence of uncertainties in material and environment, the IR intensity is indeed a range rather than a specific value. In this paper, subjected to the properties of the IR, an analytic process containing the uncertainty propagation and the reliability evaluation is investigated when taking into account that the temperature of object, the atmospheric transmittance and the spectral emissivity of materials are all regarded as uncertain parameters. For one thing, the vertex method is used to analyze and estimate the dispersion of IR intensity; for another, the safety assessment of the stealth performance for aircraft is conducted by non-probabilistic reliability analysis. For the purpose of the comparison and verification, the Monte Carlo simulation is discussed as well. The validity, usage, and efficiency of the developed methodology are demonstrated by two application examples eventually.

Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing transverse momentum in pp collisions at 8 TeV

DOE PAGES

Khachatryan, Vardan

2015-03-10

The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton–proton collisions collected at a center-of-mass energy View the MathML source with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 fb –1. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in whichmore » SUSY is approximately conserved. Furthermore, the data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation, and the results are used to set limits on squark pair production in the stealth SUSY framework.« less

Stealth Dark Matter: Dark scalar baryons through the Higgs portal

DOE PAGES

Appelquist, T.; Brower, R. C.; Buchoff, M. I.; ...

2015-10-23

We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an SU(N D) strongly coupled theory with even N D ≥ 4. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vectorlike representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to SU(4), and investigate the constraints on the model from dark meson decay, electroweakmore » precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass m B ≳ 300 GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. Furthermore, we briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.« less

Mars Express Bistatic Radar Explores Stealth

NASA Astrophysics Data System (ADS)

Simpson, Richard A.; Tyler, G. L.; Nolan, M. C.; Pätzold, M.; Häusler, B.

2006-09-01

`Stealth' is an area of approximately 2000 x 500 km (E-W by N-S), straddling Mars' equator west of Tharsis and originally mapped at λ=3.5 cm by Muhleman et al. (Science, 253, 1508-1513, 1991). The name 'Stealth' was given because of its low radar backscatter cross section in the 1991 observations. Using transmissions from Mars Express and reception at 70-m antennas of the NASA Deep Space Network (DSN), we have obtained five 'spot' measurements of oblique-incidence forward scattering from Stealth at fixed incidence angles 32°

Targeted drug delivery and enhanced intracellular release using functionalized liposomes

NASA Astrophysics Data System (ADS)

Garg, Ashish

The ability to target cancer cells using an appropriate drug delivery system can significantly reduce the associated side effects from cancer therapies and can help in improving the overall quality of life, post cancer survival. Integrin alpha5beta1 is expressed on several types of cancer cells, including colon cancer and plays an important role in tumor growth and metastasis. Thus, the ability to target the integrin alpha 5beta1 using an appropriate drug delivery nano-vector can significantly help in inhibiting tumor growth and reducing tumor metastasis. The work in this thesis focuses on designing and optimizing, functionalized stealth liposomes (liposomes covered with polyethylene glycol (PEG)) that specifically target the integrin alpha5beta1. The PEG provides a steric barrier allowing the liposomes to circulate in the blood for longer duration and the functionalizing moiety, PR_b peptide specifically recognizes and binds to integrin alpha5beta1 expressing cells. The work demonstrates that by optimizing the amount of PEG and PR_b on the liposomal interface, nano-vectors can be engineered that bind to CT26.WT colon cancer cells in a specific manner and internalize through alpha 5beta1-mediated endocytosis. To further improve the efficacy of the system, PR_b functionalized pH-sensitive stealth liposomes that exhibit triggered release under mild acidic conditions present in endocytotic vesicles were designed. The study showed that PR_b functionalized pH-sensitive stealth liposomes, undergo destabilization under mildly acidic conditions and incorporation of the PR_b peptide does not significantly affect the pH-sensitivity of the liposomes. PR_b functionalized pH-sensitive stealth liposomes bind to CT26.WT colon carcinoma cells that express integrin alpha5beta 1, undergo cellular internalization, and release their load intracellularly in a short period of time as compared to other formulations. PR_b-targeted pH-sensitive stealth liposomes encapsulating 5-fluorouracil (5-FU) show significantly higher cytotoxicity than the PR_b-targeted inert stealth liposomes and the non-targeted stealth liposomes (both pH-sensitive and inert). The studies demonstrated that optimized PR_b functionalized pH sensitive liposomes have the potential to deliver a payload, such as chemotherapeutic agents, directly to colon cancer cells in an efficient and specific manner.

Taking Control: Stealth Assessment of Deterministic Behaviors within a Game-Based System

ERIC Educational Resources Information Center

Snow, Erica L.; Likens, Aaron D.; Allen, Laura K.; McNamara, Danielle S.

2016-01-01

Game-based environments frequently afford students the opportunity to exert agency over their learning paths by making various choices within the environment. The combination of log data from these systems and dynamic methodologies may serve as a stealth means to assess how students behave (i.e., deterministic or random) within these learning…

Taking Control: Stealth Assessment of Deterministic Behaviors within a Game-Based System

ERIC Educational Resources Information Center

Snow, Erica L.; Likens, Aaron D.; Allen, Laura K.; McNamara, Danielle S.

2015-01-01

Game-based environments frequently afford students the opportunity to exert agency over their learning paths by making various choices within the environment. The combination of log data from these systems and dynamic methodologies may serve as a stealth means to assess how students behave (i.e., deterministic or random) within these learning…

Quantum steganography with large payload based on entanglement swapping of χ-type entangled states

NASA Astrophysics Data System (ADS)

Qu, Zhi-Guo; Chen, Xiu-Bo; Luo, Ming-Xing; Niu, Xin-Xin; Yang, Yi-Xian

2011-04-01

In this paper, we firstly propose a new simple method to calculate entanglement swapping of χ-type entangled states, and then present a novel quantum steganography protocol with large payload. The new protocol adopts entanglement swapping to build up the hidden channel within quantum secure direct communication with χ-type entangled states for securely transmitting secret messages. Comparing with the previous quantum steganographies, the capacity of the hidden channel is much higher, which is increased to eight bits. Meanwhile, due to the quantum uncertainty theorem and the no-cloning theorem its imperceptibility is proved to be great in the analysis, and its security is also analyzed in detail, which is proved that intercept-resend attack, measurement-resend attack, ancilla attack, man-in-the-middle attack or even Dos(Denial of Service) attack couldn't threaten it. As a result, the protocol can be applied in various fields of quantum communication.

A Statistical Study of Solar Sources of Wide Coronal Mass Ejections in 2011

NASA Astrophysics Data System (ADS)

Akiyama, S.; Yashiro, S.; Gopalswamy, N.; Makela, P. A.; Xie, H.; Olmedo, O. A.

2013-12-01

Solar surface signatures of coronal mass ejections (CMEs) are flares, filament eruptions/disappearances, EUVI waves, dimmings, and post-eruption arcades. After the SDO launch we have an excellent opportunity to investigate the solar sources of CMEs because of the high spatial- and temporal-resolution images from SDO/AIA and multiple views from SOHO, SDO, and STEREO-A/B. We examined the solar sources of all wide CMEs (width ≥ 60°) observed by either SOHO/LASCO or STEREO/SECCHI in 2011. Out of the 597 wide CMEs identified, 322 (54%) were associated with active region flares (FLs) and 164 (27%) with eruptive quiescent prominences (EPs). In 88 cases (15%) only EUV dimmings (DIMs) were observed. For the remaining 23 (4%) CMEs we were not able to identify the solar sources (UNK), i.e. they were stealth CMEs. The average speed and width of the CMEs are, 481 km/s and 115° for FLs, 349 km/s and 90° for EPs, 270 km/s and 78° for DIMs, and 171 km/s and 90° for UNKs, respectively. According to Ma et al. (2010), one third of CMEs observed by STEREO-A/B from 2009 Jan. 1 to Aug. 31 was categorized as stealth CMEs. Our study shows that the rate of stealth CMEs is much smaller for wide CMEs. We also compared the average appearance latitude of CMEs between the stealth and all wide CMEs and found that the stealth CMEs appeared from higher latitude (48°) than the general population (35°). Reference: Ma et al. (2010) ApJ, 722, 289

Detecting Stealth Dark Matter Directly through Electromagnetic Polarizability.

PubMed

Appelquist, T; Berkowitz, E; Brower, R C; Buchoff, M I; Fleming, G T; Jin, X-Y; Kiskis, J; Kribs, G D; Neil, E T; Osborn, J C; Rebbi, C; Rinaldi, E; Schaich, D; Schroeder, C; Syritsyn, S; Vranas, P; Weinberg, E; Witzel, O

2015-10-23

We calculate the spin-independent scattering cross section for direct detection that results from the electromagnetic polarizability of a composite scalar "stealth baryon" dark matter candidate, arising from a dark SU(4) confining gauge theory-"stealth dark matter." In the nonrelativistic limit, electromagnetic polarizability proceeds through a dimension-7 interaction leading to a very small scattering cross section for dark matter with weak-scale masses. This represents a lower bound on the scattering cross section for composite dark matter theories with electromagnetically charged constituents. We carry out lattice calculations of the polarizability for the lightest "baryon" states in SU(3) and SU(4) gauge theories using the background field method on quenched configurations. We find the polarizabilities of SU(3) and SU(4) to be comparable (within about 50%) normalized to the stealth baryon mass, which is suggestive for extensions to larger SU(N) groups. The resulting scattering cross sections with a xenon target are shown to be potentially detectable in the dark matter mass range of about 200-700 GeV, where the lower bound is from the existing LUX constraint while the upper bound is the coherent neutrino background. Significant uncertainties in the cross section remain due to the more complicated interaction of the polarizablity operator with nuclear structure; however, the steep dependence on the dark matter mass, 1/m(B)(6), suggests the observable dark matter mass range is not appreciably modified. We briefly highlight collider searches for the mesons in the theory as well as the indirect astrophysical effects that may also provide excellent probes of stealth dark matter.

A multihop key agreement scheme for wireless ad hoc networks based on channel characteristics.

PubMed

Hao, Zhuo; Zhong, Sheng; Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

A Multihop Key Agreement Scheme for Wireless Ad Hoc Networks Based on Channel Characteristics

PubMed Central

Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks. PMID:23766725

Bistatic and Multistatic Radar: Surveillance, Countermeasures, and Radar Cross Sections. (Latest citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1998-01-01

The bibliography contains citations concerning the design, development, testing, and evaluation of bistatic and multistatic radar used in surveillance and countermeasure technology. Citations discuss radar cross sections, target recognition and characteristics, ghost recognition, motion image compensation, and wavelet analysis. Stealth aircraft design, stealth target tracking, synthetic aperture radar, and space applications are examined.

Bistatic and Multistatic Radar: Surveillance, Countermeasures, and Radar Cross Sections. (Latest Citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1997-01-01

The bibliography contains citations concerning the design, development, testing, and evaluation of bistatic and multistatic radar used in surveillance and countermeasure technology. Citations discuss radar cross sections, target recognition and characteristics, ghost recognition, motion image compensation, and wavelet analysis. Stealth aircraft design, stealth target tracking, synthetic aperture radar, and space applications are examined.

Stealth life detection instruments aboard Curiosity

NASA Astrophysics Data System (ADS)

Levin, Gilbert V.

2012-10-01

NASA has often stated (e.g. MSL Science Corner1) that it's Mars Science Laboratory (MSL), "Curiosity," Mission to Mars carries no life detection experiments. This is in keeping with NASA's 36-year explicit ban on such, imposed immediately after the 1976 Viking Mission to Mars. The space agency attributes the ban to the "ambiguity" of that Mission's Labeled Release (LR) life detection experiment, fearing an adverse effect on the space program should a similar "inconclusive" result come from a new robotic quest. Yet, despite the NASA ban, this author, the Viking LR Experimenter, contends there are "stealth life detection instruments" aboard Curiosity. These are life detection instruments in the sense that they can free the Viking LR from the pall of ambiguity that has held it prisoner so long. Curiosity's stealth instruments are those seeking organic compounds, and the mission's high-resolution camera system. Results from any or all of these devices, coupled with the Viking LR data, can confirm the LR's life detection claim. In one possible scenario, Curiosity can, of itself, completely corroborate the finding of life on Mars. MSL has just successfully landed on Mars. Hopefully, its stealth confirmations of life will be reported shortly.

Integrating Stealth

DTIC Science & Technology

2015-12-01

Over the past two decades the United States has revolutionized the war fighting industry with advancements in Low Observable ( LO ) technology and...precision strike capability. Advanced LO weapon systems such as the F-35, F-22 and the B-2 have been developed and portrayed as stealth aircraft. In...Because LO technology is in a physical form, methods can and have been developed to exploit the inherent weaknesses. Additionally, the technological

Clusterin in the protein corona plays a key role in the stealth effect of nanoparticles against phagocytes.

PubMed

Aoyama, Michihiko; Hata, Katsutomo; Higashisaka, Kazuma; Nagano, Kazuya; Yoshioka, Yasuo; Tsutsumi, Yasuo

2016-11-25

In biological fluids, nanoparticles interact with biological components such as proteins, and a layer called the "protein corona" forms around the nanoparticles. It is believed that the composition of the protein corona affects the cellular uptake and in vivo biodistribution of nanoparticles; however, the key proteins of the protein corona that control the biological fate of nanoparticles remain unclear. Recently, it was reported that clusterin binding to pegylated nanoparticles is important for the stealth effect of pegylated nanoparticles in phagocytes. However, the effect of clusterin on non-pegylated nanoparticles is unknown, although it is known that clusterin is present in the protein corona of non-pegylated nanoparticles. Here, we assessed the stealth effect of clusterin in the corona of non-pegylated silver nanoparticles and silica nanoparticles. We found that serum- and plasma-protein corona inhibited the cellular uptake of silver nanoparticles and silica nanoparticles in phagocytes and that the plasma-protein corona showed a greater stealth effect compared with the serum-protein corona. Clusterin was present in both the serum- and plasma-protein corona, but was present at a higher level in the plasma-protein corona than in the serum-protein corona. Clusterin binding to silver nanoparticles and silica nanoparticles suppressed the cellular uptake of nanoparticles in human macrophage-like cells (THP-1 cells). Although further studies are required to determine how clusterin suppresses non-specific cellular uptake in phagocytes, our data suggest that clusterin plays a key role in the stealth effect of not only pegylated nanoparticles but also non-pegylated nanoparticles. Copyright © 2016 Elsevier Inc. All rights reserved.

Detecting Stealth Dark Matter Directly through Electromagnetic Polarizability

DOE PAGES

Appelquist, T.; Berkowitz, E.; Brower, R. C.; ...

2015-10-23

We calculate the spin-independent scattering cross section for direct detection that results from the electromagnetic polarizability of a composite scalar “stealth baryon” dark matter candidate, arising from a dark SU(4) confining gauge theory—“stealth dark matter.” In the nonrelativistic limit, electromagnetic polarizability proceeds through a dimension-7 interaction leading to a very small scattering cross section for dark matter with weak-scale masses. This represents a lower bound on the scattering cross section for composite dark matter theories with electromagnetically charged constituents. We carry out lattice calculations of the polarizability for the lightest “baryon” states in SU(3) and SU(4) gauge theories using themore » background field method on quenched configurations. We find the polarizabilities of SU(3) and SU(4) to be comparable (within about 50%) normalized to the stealth baryon mass, which is suggestive for extensions to larger SU(N) groups. The resulting scattering cross sections with a xenon target are shown to be possibly detectable in the dark matter mass range of about 200–700 GeV, where the lower bound is from the existing LUX constraint while the upper bound is the coherent neutrino background. Significant uncertainties in the cross section remain due to the more complicated interaction of the polarizablity operator with nuclear structure; however, the steep dependence on the dark matter mass, 1/m 6 B, suggests the observable dark matter mass range is not appreciably modified. We highlight collider searches for the mesons in the theory as well as the indirect astrophysical effects that may also provide excellent probes of stealth dark matter.« less

Learning Communities: An Emerging Phenomenon

ERIC Educational Resources Information Center

Galinsky, Ellen

2012-01-01

The central purpose of curriculum, assessment, and teaching, especially in putting them together, is to improve children's and adult's learning. Examples of this came to the author via modern communication media and are being furthered through such technology. Soon after the publication of her book "Mind in the Making" (MITM) in 2010, the author…

How sailfish use their bills to capture schooling prey

PubMed Central

Domenici, P.; Wilson, A. D. M.; Kurvers, R. H. J. M.; Marras, S.; Herbert-Read, J. E.; Steffensen, J. F.; Krause, S.; Viblanc, P. E.; Couillaud, P.; Krause, J.

2014-01-01

The istiophorid family of billfishes is characterized by an extended rostrum or ‘bill’. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to feed on prey. Here, we present the first unequivocal evidence of how the bill is used by Atlantic sailfish (Istiophorus albicans) to attack schooling sardines in the open ocean. Using high-speed video-analysis, we show that (i) sailfish manage to insert their bill into sardine schools without eliciting an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey. PMID:24759865

JPRS Report, Science & Technology. China: Stealth/Counter-Stealth Research.

DTIC Science & Technology

1992-11-19

Frequency-Selective Surfaces 92FE0801F Beijing DIANZIXUEBAO [ACTA ELECTRONICA SINICA] in Chinese Vol 20 No 6, Jun 92 pp 85-88 [Article by Shen...microwave devices and electromag- netic scattering. Motion Compensation Method in ISAR Imaging 92FE0801A Beijing DIANZIXUEBAO [ACTA ELECTRONICA ...Chinese Society of Electronics and an editor of DIANZI XUEBAO [ACTA ELECTRONICA SINICA]. Deng Wenbiao Born in February 1961, he graduated from the

A Stealth Intervention: The GLAMA (Girls! Lead! Achieve! Mentor! Activate!) and BLAST (Boys! Lead! Activate! Succeed Together!) School Connectedness, Peer Leadership and Physical Activity Transition Program

ERIC Educational Resources Information Center

Jenkinson, Kate A.; Naughton, Geraldine; Benson, Amanda C.

2018-01-01

This study investigated the effects of the GLAMA (Girls! Lead! Achieve! Mentor! Activate!) and BLAST (Boys! Lead! Activate! Succeed Together!) controlled 8-week peer-led stealth intervention on school connectedness and physical activity self-efficacy (PASE). The GLAMA and BLAST sessions were conducted during curriculum time in an Australian state…

Stealth liposomes: review of the basic science, rationale, and clinical applications, existing and potential

PubMed Central

Immordino, Maria Laura; Dosio, Franco; Cattel, Luigi

2006-01-01

Among several promising new drug-delivery systems, liposomes represent an advanced technology to deliver active molecules to the site of action, and at present several formulations are in clinical use. Research on liposome technology has progressed from conventional vesicles (“first-generation liposomes”) to “second-generation liposomes”, in which long-circulating liposomes are obtained by modulating the lipid composition, size, and charge of the vesicle. Liposomes with modified surfaces have also been developed using several molecules, such as glycolipids or sialic acid. A significant step in the development of long-circulating liposomes came with inclusion of the synthetic polymer poly-(ethylene glycol) (PEG) in liposome composition. The presence of PEG on the surface of the liposomal carrier has been shown to extend blood-circulation time while reducing mononuclear phagocyte system uptake (stealth liposomes). This technology has resulted in a large number of liposome formulations encapsulating active molecules, with high target efficiency and activity. Further, by synthetic modification of the terminal PEG molecule, stealth liposomes can be actively targeted with monoclonal antibodies or ligands. This review focuses on stealth technology and summarizes pre-clinical and clinical data relating to the principal liposome formulations; it also discusses emerging trends of this promising technology. PMID:17717971

The Soviet Stealth Fighter: Check or Checkmate

DTIC Science & Technology

1988-04-01

pp. 20-31. 25 11. Bussert, Jim and Paul Beaver. "Soviet Submarine Hull Coatings," Defense Electronics (August 1987), pp. 26-27. 12. Canan , James W...Aircraft (January 1987), pp. 50-59. 34. Vorobyov, Ivan , Major-General. "Formula for Victory," Soviet Military Review (November 1986), pp. 14-15. 35...34Stealth Somber Taking Shape," International Combat Aircraft (September 1987), pp. 27-31. Vozobyov, Ivan , Major-General. "New Weapons Require Sound

Security analysis and improvement of a privacy authentication scheme for telecare medical information systems.

PubMed

Wu, Fan; Xu, Lili

2013-08-01

Nowadays, patients can gain many kinds of medical service on line via Telecare Medical Information Systems(TMIS) due to the fast development of computer technology. So security of communication through network between the users and the server is very significant. Authentication plays an important part to protect information from being attacked by malicious attackers. Recently, Jiang et al. proposed a privacy enhanced scheme for TMIS using smart cards and claimed their scheme was better than Chen et al.'s. However, we have showed that Jiang et al.'s scheme has the weakness of ID uselessness and is vulnerable to off-line password guessing attack and user impersonation attack if an attacker compromises the legal user's smart card. Also, it can't resist DoS attack in two cases: after a successful impersonation attack and wrong password input in Password change phase. Then we propose an improved mutual authentication scheme used for a telecare medical information system. Remote monitoring, checking patients' past medical history record and medical consultant can be applied in the system where information transmits via Internet. Finally, our analysis indicates that the suggested scheme overcomes the disadvantages of Jiang et al.'s scheme and is practical for TMIS.

Filtering methods for broadcast authentication against PKC-based denial of service in WSN: a survey

NASA Astrophysics Data System (ADS)

Afianti, Farah; Wirawan, Iwan; Suryani, Titiek

2017-11-01

Broadcast authentication is used to determine legitimate packet from authorized user. The received packet can be forwarded or used for the further purpose. The use of digital signature is one of the compromising methods but it is followed by high complexity especially in the verification process. That phenomenon is used by the adversary to force the user to verify a lot of false packet data. Kind of Denial of Service (DoS) which attacks the main signature can be mitigated by using pre-authentication methods as the first layer to filter false packet data. The objective of the filter is not replacing the main signature but as an addition to actual verification in the sensor node. This paper contributes in comparing the cost of computation, storage, and communication among several filters. The result shows Pre- Authenticator and Dos Attack-Resistant scheme have the lower overhead than the others. Thus followed by needing powerful sender. Moreover, the key chain is promising methods because of efficiency and effectiveness.

Design on compatible stealth photonic crystal of nearmiddle infrared and 1.06 μm laser

NASA Astrophysics Data System (ADS)

Zhang, Ji-kui; Wang, Jia-Chun; Wang, Qi-Chao

2016-01-01

In the near and middle infrared atmospheric window, infrared stealth material require a low absorptivity (which means a low emissivity according to Kirchhoff's law of black body), at the same time, it also requires high absorptivity so as to decrease the reflectance at military laser wavelength of 1.06μm. Under this circumstances, compatible stealth of infrared and laser is an urgent demand, but the demand is ambivalent for conventional materials. Photonic crystal (PC), as a new type of artificial periodic structure function material, can realize broadband thermal infrared stealth based on its high-reflection photon forbidden band(also called photonic band gap). The high-reflection photon forbidden band of PC can be adjusted to near and middle infrared wave band through some rational methods. When a defect was added into the periodic structure of PC, a "hole-digging" reflection spectrum, which is high absorption at military laser wavelength of 1.06μm, can be achieved, so compatible stealth of near and middle infrared and military laser wavelength of 1.06μm can be achieved too. In this paper, we selected near and middle infrared-transparent materials, Te and MgF2 , as high refractive index and low refractive index material respectively, and designed a one-dimensional one-defect-mode PC whose photon forbidden band was broadened to 1-5μm by constructing two photonic crystals into one. The optical property of the PC was calculated by Transfer matrix method(TMM) of thin-film optical theory, and the results shows that the as-designed PC has a high spectral reflectance in the near and middle infrared band, among which the reflectivity in 1.68μm 5.26μm band reached more than 90%, and the 2.48 5.07μm band even reached 99.99%. The result also shows that between the band gap of 1-5μm, there are one defect mode locating in the wavelength of 1.06μm, whose reflectance is below 0.70%, which means its spectral absorptivity is greater than 99.30%. All the above we have discussed proved that this "hole-digging spectrum" PC can realize the compatible stealth of near and middle infrared and 1.06μm military laser.

Radar Versus Stealth: Passive Radar and the Future of U.S. Military Power

DTIC Science & Technology

2009-01-01

minimizing, if not nul- lifying , the advantages of the defensive.”3 Douhet did not envision the many sur- face-to-air threats that would evolve over the...is emerging, enabled by advances in networked computing and passive radar technology. Because of their potential to counter stealth-based airpower...waveforms include FM and AM radio, television, digital audio/video broadcast, and cellular phone networks .38 Today, passive radar is often configured as a

A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks.

PubMed

Saleh, Mohammed A; Abdul Manaf, Azizah

2015-01-01

The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS) and distributed denial of service (DDoS) attacks. Despite many researchers' efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF). The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework's schemes (layers). Firstly, an outer blocking (OB) scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA) scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB) scheme is to eliminate high rate DDoS (HR-DDoS) and flash crowd (FC) attacks. Compared to the previous researches, our framework's design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks.

A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks

PubMed Central

Saleh, Mohammed A.; Abdul Manaf, Azizah

2015-01-01

The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS) and distributed denial of service (DDoS) attacks. Despite many researchers' efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF). The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework's schemes (layers). Firstly, an outer blocking (OB) scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA) scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB) scheme is to eliminate high rate DDoS (HR-DDoS) and flash crowd (FC) attacks. Compared to the previous researches, our framework's design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks. PMID:26065015

Placement of iliosacral screws using 3D image-guided (O-Arm) technology and Stealth Navigation: comparison with traditional fluoroscopy.

PubMed

Theologis, A A; Burch, S; Pekmezci, M

2016-05-01

We compared the accuracy, operating time and radiation exposure of the introduction of iliosacral screws using O-arm/Stealth Navigation and standard fluoroscopy. Iliosacral screws were introduced percutaneously into the first sacral body (S1) of ten human cadavers, four men and six women. The mean age was 77 years (58 to 85). Screws were introduced using a standard technique into the left side of S1 using C-Arm fluoroscopy and then into the right side using O-Arm/Stealth Navigation. The radiation was measured on the surgeon by dosimeters placed under a lead thyroid shield and apron, on a finger, a hat and on the cadavers. There were no neuroforaminal breaches in either group. The set-up time for the O-Arm was significantly longer than for the C-Arm, while total time for placement of the screws was significantly shorter for the O-Arm than for the C-Arm (p = 0.001). The mean absorbed radiation dose during fluoroscopy was 1063 mRad (432.5 mRad to 4150 mRad). No radiation was detected on the surgeon during fluoroscopy, or when he left the room during the use of the O-Arm. The mean radiation detected on the cadavers was significantly higher in the O-Arm group (2710 mRem standard deviation (sd) 1922) than during fluoroscopy (11.9 mRem sd 14.8) (p < 0.01). O-Arm/Stealth Navigation allows for faster percutaneous placement of iliosacral screws in a radiation-free environment for surgeons, albeit with the same accuracy and significantly more radiation exposure to cadavers, when compared with standard fluoroscopy. Placement of iliosacral screws with O-Arm/Stealth Navigation can be performed safely and effectively. Cite this article: Bone Joint J 2016;98-B:696-702. ©2016 The British Editorial Society of Bone & Joint Surgery.

Intrabilayer 64Cu Labeling of Photoactivatable, Doxorubicin-Loaded Stealth Liposomes.

PubMed

Luo, Dandan; Goel, Shreya; Liu, Hai-Jun; Carter, Kevin A; Jiang, Dawei; Geng, Jumin; Kutyreff, Christopher J; Engle, Jonathan W; Huang, Wei-Chiao; Shao, Shuai; Fang, Chao; Cai, Weibo; Lovell, Jonathan F

2017-12-26

Doxorubicin (Dox)-loaded stealth liposomes (similar to those in clinical use) can incorporate small amounts of porphyrin-phospholipid (PoP) to enable chemophototherapy (CPT). PoP is also an intrinsic and intrabilayer 64 Cu chelator, although how radiolabeling impacts drug delivery has not yet been assessed. Here, we show that 64 Cu can radiolabel the stable bilayer of preformed Dox-loaded PoP liposomes with inclusion of 1% ethanol without inducing drug leakage. Dox-PoP liposomes labeled with intrabilayer copper behaved nearly identically to unlabeled ones in vitro and in vivo with respect to physical parameters, pharmacokinetics, and CPT efficacy. Positron emission tomography and near-infrared fluorescence imaging visualized orthotopic mammary tumors in mice with passive liposome accumulation following administration. A single CPT treatment with 665 nm light (200 J/cm 2 ) strongly inhibited primary tumor growth. Liposomes accumulated in lung metastases, based on NIR imaging. These results establish the feasibility of CPT interventions guided by intrinsic multimodal imaging of Dox-loaded stealth PoP liposomes.

Investigation of terahertz waves propagating through far infrared/CO2 laser stealth-compatible coating based on one-dimensional photonic crystal

NASA Astrophysics Data System (ADS)

Wang, Qichao; Wang, Jiachun; Zhao, Dapeng; Zhang, Jikui; Li, Zhigang; Chen, Zongsheng; Zeng, Jie; Miao, Lei; Shi, Jiaming

2016-11-01

We propose a new method to disclose the camouflaged targets coated with far infrared/CO2 laser stealth-compatible coating by utilizing terahertz (THz) radar. A coating based on one-dimensional photonic crystal (1DPC) with a defect mode is specially designed and successfully prepared, which possesses a high reflectivity in 8-14 μm waveband and a low reflectivity at 10.6 μm, by alternating thin films of Ge, ZnSe and Si. The propagation characteristic of 0.3-2 THz wave at incident angle from 0° to 80° in such PC coating is investigated theoretically based on characteristic matrix method. The maximal transmittance is up to 92%, and the absorptivity keeps lower than 0.5% over the whole band. The results are verified by experiments, which demonstrate the feasibility of using THz radar to detect the targets covered with such stealth-compatible coatings.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khachatryan, Vardan

The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton–proton collisions collected at a center-of-mass energy View the MathML source with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 fb –1. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in whichmore » SUSY is approximately conserved. Furthermore, the data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation, and the results are used to set limits on squark pair production in the stealth SUSY framework.« less

Antibody derivatization and conjugation strategies: application in preparation of stealth immunoliposome to target chemotherapeutics to tumor.

PubMed

Manjappa, Arehalli S; Chaudhari, Kiran R; Venkataraju, Makam P; Dantuluri, Prudhviraju; Nanda, Biswarup; Sidda, Chennakesavulu; Sawant, Krutika K; Murthy, Rayasa S Ramachandra

2011-02-28

A great deal of effort has been made over the years to develop liposomes that have targeting vectors (oligosaccharides, peptides, proteins and vitamins) attached to the bilayer surface. Most studies have focused on antibody conjugates since procedures for producing highly specific monoclonal antibodies are well established. Antibody conjugated liposomes have recently attracted a great deal of interest, principally because of their potential use as targeted drug delivery systems and in diagnostic applications. A number of methods have been reported for coupling antibodies to the surface of stealth liposomes. The objective of this review is to enumerate various strategies which are employed in the modification and conjugation of antibodies to the surface of stealth liposomes. This review also describes various derivatization techniques of lipids prior and after their use in the preparation of liposomes. The use of single chain variable fragments and affibodies as targeting ligands in the preparation of immunoliposomes is also discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

Editorial on Future Jet Technologies

NASA Astrophysics Data System (ADS)

Gal-Or, Benjamin

2014-08-01

Advanced jet engines do not operate in an application vacuum. Their optimal use in advanced military applications drives much of their basic innovative research and development, especially when new needs arise in the rapidly changing domains of stealth-agile, fighter aircraft and tailless-stealth, Jet-Steered, Unmanned Air Vehicles (JS-UAV). For these reasons we periodically update this Journal with new trends that affect, and sometimes control, research and development of future jet-engines. One relevant example is the recently unmasked RQ-180 stealth-tailless drone, which is an improved version of the smaller, RQ-170 captured by Iran. Most important, with the new X-47B/C tailless-stealth JS-UAV, it is to dominate future uses of fuel-efficient jet-engines, especially for operating in dusty environments. The RQ-180 has been secretly designed and funded since 2008. It is based on a classified, 1986, parent Israeli Patents 78402, which protect hundreds design and testing trade secrets taken from 1986 to 1997 by the United States Government (USG) via classified contracts with USG-Contractors Boeing, Lockheed, General Dynamics and General Electric, as revealed by a December 6, 2013 Aviation Week [1-3] and U.S. Court of Appeals for the Federal Circuit, Case 2014-5028, Docket 12 [4]. The new RQ-180 design explains the recent U.S. Air Force ISR shift away from "permissive" environments - such as Iraq and Afghanistan, where non-stealthy Global Hawk and General Atomics' Reaper operate - toward new missions in highly "contested" or strongly "denied" enemy airspaces.

Accuracy of screw fixation using the O-arm® and StealthStation® navigation system for unstable pelvic ring fractures.

PubMed

Takeba, Jun; Umakoshi, Kensuke; Kikuchi, Satoshi; Matsumoto, Hironori; Annen, Suguru; Moriyama, Naoki; Nakabayashi, Yuki; Sato, Norio; Aibiki, Mayuki

2018-04-01

Screw fixation for unstable pelvic ring fractures is generally performed using the C-arm. However, some studies reported erroneous piercing with screws, nerve injuries, and vessel injuries. Recent studies have reported the efficacy of screw fixations using navigation systems. The purpose of this retrospective study was to investigate the accuracy of screw fixation using the O-arm ® imaging system and StealthStation ® navigation system for unstable pelvic ring fractures. The participants were 10 patients with unstable pelvic ring fractures, who underwent screw fixations using the O-arm StealthStation navigation system (nine cases with iliosacral screw and one case with lateral compression screw). We investigated operation duration, bleeding during operation, the presence of complications during operation, and the presence of cortical bone perforation by the screws based on postoperative CT scan images. We also measured the difference in screw tip positions between intraoperative navigation screen shot images and postoperative CT scan images. The average operation duration was 71 min, average bleeding was 12 ml, and there were no nerve or vessel injuries during the operation. There was no cortical bone perforation by the screws. The average difference between intraoperative navigation images and postoperative CT images was 2.5 ± 0.9 mm, for all 18 screws used in this study. Our results suggest that the O-arm StealthStation navigation system provides accurate screw fixation for unstable pelvic ring fractures.

Nondestructive Detection of Structural Damage Uniquely Associated with Fatigue

DTIC Science & Technology

1974-07-01

corrosion were not as numerous as cracks caused by fatigue. Stress corrosion cracking occurred mostly at fillet radius, shear pinhole, and the web of...nil i. i^mji^mitm^mm^mmmmmw^mmmtmi>i>i.vi\\ -^^ wix ^w 0) a E re i A c 0) 1- D o ^el /l Current le // T wi th ~ transducer — ’"A

Security enhanced anonymous multiserver authenticated key agreement scheme using smart cards and biometrics.

PubMed

Choi, Younsung; Nam, Junghyun; Lee, Donghoon; Kim, Jiye; Jung, Jaewook; Won, Dongho

2014-01-01

An anonymous user authentication scheme allows a user, who wants to access a remote application server, to achieve mutual authentication and session key establishment with the server in an anonymous manner. To enhance the security of such authentication schemes, recent researches combined user's biometrics with a password. However, these authentication schemes are designed for single server environment. So when a user wants to access different application servers, the user has to register many times. To solve this problem, Chuang and Chen proposed an anonymous multiserver authenticated key agreement scheme using smart cards together with passwords and biometrics. Chuang and Chen claimed that their scheme not only supports multiple servers but also achieves various security requirements. However, we show that this scheme is vulnerable to a masquerade attack, a smart card attack, a user impersonation attack, and a DoS attack and does not achieve perfect forward secrecy. We also propose a security enhanced anonymous multiserver authenticated key agreement scheme which addresses all the weaknesses identified in Chuang and Chen's scheme.

Establishment of Chronic Infection: Brucella's Stealth Strategy

PubMed Central

Ahmed, Waqas; Zheng, Ke; Liu, Zheng-Fei

2016-01-01

Brucella is a facultative intracellular pathogen that causes zoonotic infection known as brucellosis which results in abortion and infertility in natural host. Humans, especially in low income countries, can acquire infection by direct contact with infected animal or by consumption of animal products and show high morbidity, severe economic losses and public health problems. However for survival, host cells develop complex immune mechanisms to defeat and battle against attacking pathogens and maintain a balance between host resistance and Brucella virulence. On the other hand as a successful intracellular pathogen, Brucella has evolved multiple strategies to evade immune response mechanisms to establish persistent infection and replication within host. In this review, we mainly summarize the “Stealth” strategies employed by Brucella to modulate innate and the adaptive immune systems, autophagy, apoptosis and possible role of small noncoding RNA in the establishment of chronic infection. The purpose of this review is to give an overview for recent understanding how this pathogen evades immune response mechanisms of host, which will facilitate to understanding the pathogenesis of brucellosis and the development of novel, more effective therapeutic approaches to treat brucellosis. PMID:27014640

The Stealth Biplane: a Proposal in Response to a Low Reynolds Number Station Keeping Mission

NASA Technical Reports Server (NTRS)

Walsh, Timothy E.; Flynn, Kevin T.; Donovan, Steven; Paul, Chris; Pangilinan, Harold; Padgett, John; Twomey, Daniel

1990-01-01

The Stealth Biplane is conceived and constructed to serve as a remotely piloted vehicle designed to navigate a low-level figure-eight course at a target Reynolds number of 100,000. This flight vehicle will combine the latest in lightweight radio controlled hardware in conjunction with current low Reynolds number aerodynamic research to demonstrate feasible operation in a variety of applications. These potential low Reynolds number applications include high altitude atmospheric sampling, search and rescue, and even law enforcement. Design specs and fabrication technique are discussed.

Evaluation of blood-brain barrier-stealth nanocomposites for in situ glioblastoma theranostics applications

NASA Astrophysics Data System (ADS)

Su, Chia-Hao; Tsai, Ching-Yi; Tomanek, Boguslaw; Chen, Wei-Yu; Cheng, Fong-Yu

2016-04-01

The blood-brain barrier (BBB) is a physiological structure of the blood vessels in the brain. The BBB efficiently traps most therapeutic drugs in the blood vessels and stops them from entering the brain tissue, resulting in a decreased therapeutic efficiency. In this study, we developed BBB-stealth nanocomposites composed of iron oxide (Fe3O4) nanoparticles (NPs) as a safe nanocarrier for glioblastoma therapy. We showed the antitumor activity of Dox/alg-Fe3O4 NPs using in vitro and in vivo tests. We demonstrated that G23-alg-Fe3O4 NPs crossed the BBB and entered the brain. In situ glioblastoma tumor-bearing mice were used to successfully evaluate the antitumor activity of G23-Dox/alg-Fe3O4 NPs. Magnetic resonance imaging (MRI) and bioluminescence imaging (BLI) confirmed the BBB crossing. The BBB-stealth nanocomposites show great potential for a proof-of-concept clinical trial as a theranostics platform for human brain tumor therapy.The blood-brain barrier (BBB) is a physiological structure of the blood vessels in the brain. The BBB efficiently traps most therapeutic drugs in the blood vessels and stops them from entering the brain tissue, resulting in a decreased therapeutic efficiency. In this study, we developed BBB-stealth nanocomposites composed of iron oxide (Fe3O4) nanoparticles (NPs) as a safe nanocarrier for glioblastoma therapy. We showed the antitumor activity of Dox/alg-Fe3O4 NPs using in vitro and in vivo tests. We demonstrated that G23-alg-Fe3O4 NPs crossed the BBB and entered the brain. In situ glioblastoma tumor-bearing mice were used to successfully evaluate the antitumor activity of G23-Dox/alg-Fe3O4 NPs. Magnetic resonance imaging (MRI) and bioluminescence imaging (BLI) confirmed the BBB crossing. The BBB-stealth nanocomposites show great potential for a proof-of-concept clinical trial as a theranostics platform for human brain tumor therapy. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c6nr00280c

Generationing, Stealthing, and Gift Giving: The Intentional Transmission of HIV by HIV-Positive Men to their HIV-Negative Sex Partners.

PubMed

Klein, Hugh

2014-11-06

Gift giving is the process by which an HIV-positive person purposely infects an HIV-negative person with HIV, usually with that person's knowledge and consent. Little has been written about this HIV transmission practice. In this paper, two specific types of gift giving - generationing and stealthing - are explained and introduced to the scientific literature. Generationing is a type of gift giving in which one gift giver successfully infects a previously-uninfected man with HIV, and then the two men collaborate in an effort to seroconvert another man, and so forth. Stealthing is another type of gift giving in which an HIV-positive man actively tries to infect an HIV-negative man with HIV, without the latter's knowledge or consent. The present study reports on the prevalence of gift giving (4.6%) in a population of men who use the Internet specifically to identify partners for unprotected sex. The research is based on a national random sample of 332 men who have sex with men, identified from 16 websites. Data were collected via telephone interviews conducted between January 2008 and May 2009. The paper concludes with a discussion of the implications of these findings for HIV prevention and intervention efforts. Most notably, to the extent that generationing, stealthing, and gift giving occur among MSM, they represent a very high risk of HIV transmission. More work needs to be done to understand these behaviors, the factors that underlie them, and to determine how prevalent they are in the bare-backing population of MSM.

Generationing, Stealthing, and Gift Giving: The Intentional Transmission of HIV by HIV-Positive Men to their HIV-Negative Sex Partners

PubMed Central

Klein, Hugh

2014-01-01

Gift giving is the process by which an HIV-positive person purposely infects an HIV-negative person with HIV, usually with that person’s knowledge and consent. Little has been written about this HIV transmission practice. In this paper, two specific types of gift giving – generationing and stealthing – are explained and introduced to the scientific literature. Generationing is a type of gift giving in which one gift giver successfully infects a previously-uninfected man with HIV, and then the two men collaborate in an effort to seroconvert another man, and so forth. Stealthing is another type of gift giving in which an HIV-positive man actively tries to infect an HIV-negative man with HIV, without the latter’s knowledge or consent. The present study reports on the prevalence of gift giving (4.6%) in a population of men who use the Internet specifically to identify partners for unprotected sex. The research is based on a national random sample of 332 men who have sex with men, identified from 16 websites. Data were collected via telephone interviews conducted between January 2008 and May 2009. The paper concludes with a discussion of the implications of these findings for HIV prevention and intervention efforts. Most notably, to the extent that generationing, stealthing, and gift giving occur among MSM, they represent a very high risk of HIV transmission. More work needs to be done to understand these behaviors, the factors that underlie them, and to determine how prevalent they are in the bare-backing population of MSM. PMID:26973945

Different effect of hydrogelation on anti-fouling and circulation properties of dextran–iron oxide nanoparticles

PubMed Central

Karmali, Priya Prakash; Chao, Ying; Park, Ji-Ho (Joe); Sailor, Michael J.; Ruoslahti, Erkki; Esener, Sadik C.; Simberg, Dmitri

2012-01-01

Premature recognition and clearance of nanoparticulate imaging and therapeutic agents by macrophages in the tissues can dramatically reduce both the nanoparticle half-life and delivery to the diseased tissue. Grafting nanoparticles with hydrogels prevents nanoparticulate recognition by liver and spleen macrophages and greatly prolongs circulation times in vivo. Understanding the mechanisms by which hydrogels achieve this “stealth” effect has implications for the design of long-circulating nanoparticles. Thus, the role of plasma protein absorption in the hydrogel effect is not yet understood. Short-circulating dextran-coated iron oxide nanoparticles could be converted into stealth hydrogel nanoparticles by crosslinking with 1-chloro-2,3-epoxypropane. We show that hydrogelation did not affect the size, shape and zeta potential, but completely prevented the recognition and clearance by liver macrophages in vivo. Hydrogelation decreased the number of hydroxyl groups on the nanoparticle surface and reduced the binding of the anti-dextran antibody. At the same time, hydrogelation did not reduce the absorption of cationic proteins on the nanoparticle surface. Specifically, there was no effect on the binding of kininogen, histidine-rich glycoprotein, and protamine sulfate to the anionic nanoparticle surface. In addition, hydrogelation did not prevent activation of plasma kallikrein on the metal oxide surface. These data suggest that: (a) a stealth hydrogel coating does not mask charge interactions with iron oxide surface and (b) the total blockade of plasma protein absorption is not required for maintaining iron oxide nanoparticles’ long-circulating stealth properties. These data illustrate a novel, clinically promising property of long-circulating stealth nanoparticles. PMID:22243419

The use of computerized image guidance in lumbar disk arthroplasty.

PubMed

Smith, Harvey E; Vaccaro, Alexander R; Yuan, Philip S; Papadopoulos, Stephen; Sasso, Rick

2006-02-01

Surgical navigation systems have been increasingly studied and applied in the application of spinal instrumentation. Successful disk arthroplasty requires accurate midline and rotational positioning for optimal function and longevity. A surgical simulation study in human cadaver specimens was done to evaluate and compare the accuracy of standard fluoroscopy, computer-assisted fluoroscopic image guidance, and Iso-C3D image guidance in the placement of lumbar intervertebral disk replacements. Lumbar intervertebral disk prostheses were placed using three different image guidance techniques in three human cadaver spine specimens at multiple levels. Postinstrumentation accuracy was assessed with thin-cut computed tomography scans. Intervertebral disk replacements placed using the StealthStation with Iso-C3D were more accurately centered than those placed using the StealthStation with FluoroNav and standard fluoroscopy. Intervertebral disk replacements placed with Iso-C3D and FluoroNav had improved rotational divergence compared with standard fluoroscopy. Iso-C3D and FluoroNav had a smaller interprocedure variance than standard fluoroscopy. These results did not approach statistical significance. Relative to both virtual and standard fluoroscopy, use of the StealthStation with Iso-C3D resulted in improved accuracy in centering the lumbar disk prosthesis in the coronal midline. The StealthStation with FluoroNav appears to be at least equivalent to standard fluoroscopy and may offer improved accuracy with rotational alignment while minimizing radiation exposure to the surgeon. Surgical guidance systems may offer improved accuracy and less interprocedure variation in the placement of intervertebral disk replacements than standard fluoroscopy. Further study regarding surgical navigation systems for intervertebral disk replacement is warranted.

Security enhanced multi-factor biometric authentication scheme using bio-hash function.

PubMed

Choi, Younsung; Lee, Youngsook; Moon, Jongho; Won, Dongho

2017-01-01

With the rapid development of personal information and wireless communication technology, user authentication schemes have been crucial to ensure that wireless communications are secure. As such, various authentication schemes with multi-factor authentication have been proposed to improve the security of electronic communications. Multi-factor authentication involves the use of passwords, smart cards, and various biometrics to provide users with the utmost privacy and data protection. Cao and Ge analyzed various authentication schemes and found that Younghwa An's scheme was susceptible to a replay attack where an adversary masquerades as a legal server and a user masquerading attack where user anonymity is not provided, allowing an adversary to execute a password change process by intercepting the user's ID during login. Cao and Ge improved upon Younghwa An's scheme, but various security problems remained. This study demonstrates that Cao and Ge's scheme is susceptible to a biometric recognition error, slow wrong password detection, off-line password attack, user impersonation attack, ID guessing attack, a DoS attack, and that their scheme cannot provide session key agreement. Then, to address all weaknesses identified in Cao and Ge's scheme, this study proposes a security enhanced multi-factor biometric authentication scheme and provides a security analysis and formal analysis using Burrows-Abadi-Needham logic. Finally, the efficiency analysis reveals that the proposed scheme can protect against several possible types of attacks with only a slightly high computational cost.

Are Metabolic Signatures Mediating the Relationship between Lifestyle Factors and Hepatocellular Carcinoma Risk? Results from a Nested Case-Control Study in EPIC.

PubMed

Assi, Nada; Thomas, Duncan C; Leitzmann, Michael; Stepien, Magdalena; Chajès, Véronique; Philip, Thierry; Vineis, Paolo; Bamia, Christina; Boutron-Ruault, Marie-Christine; Sandanger, Torkjel M; Molinuevo, Amaia; Boshuizen, Hendriek C; Sundkvist, Anneli; Kühn, Tilman; Travis, Ruth C; Overvad, Kim; Riboli, Elio; Gunter, Marc J; Scalbert, Augustin; Jenab, Mazda; Ferrari, Pietro; Viallon, Vivian

2018-05-01

Background: The "meeting-in-the-middle" (MITM) is a principle to identify exposure biomarkers that are also predictors of disease. The MITM statistical framework was applied in a nested case-control study of hepatocellular carcinoma (HCC) within European Prospective Investigation into Cancer and Nutrition (EPIC), where healthy lifestyle index (HLI) variables were related to targeted serum metabolites. Methods: Lifestyle and targeted metabolomic data were available from 147 incident HCC cases and 147 matched controls. Partial least squares analysis related 7 lifestyle variables from a modified HLI to a set of 132 serum-measured metabolites and a liver function score. Mediation analysis evaluated whether metabolic profiles mediated the relationship between each lifestyle exposure and HCC risk. Results: Exposure-related metabolic signatures were identified. Particularly, the body mass index (BMI)-associated metabolic component was positively related to glutamic acid, tyrosine, PC aaC38:3, and liver function score and negatively to lysoPC aC17:0 and aC18:2. The lifetime alcohol-specific signature had negative loadings on sphingomyelins (SM C16:1, C18:1, SM(OH) C14:1, C16:1 and C22:2). Both exposures were associated with increased HCC with total effects (TE) = 1.23 (95% confidence interval = 0.93-1.62) and 1.40 (1.14-1.72), respectively, for BMI and alcohol consumption. Both metabolic signatures mediated the association between BMI and lifetime alcohol consumption and HCC with natural indirect effects, respectively, equal to 1.56 (1.24-1.96) and 1.09 (1.03-1.15), accounting for a proportion mediated of 100% and 24%. Conclusions: In a refined MITM framework, relevant metabolic signatures were identified as mediators in the relationship between lifestyle exposures and HCC risk. Impact: The understanding of the biological basis for the relationship between modifiable exposures and cancer would pave avenues for clinical and public health interventions on metabolic mediators. Cancer Epidemiol Biomarkers Prev; 27(5); 531-40. ©2018 AACR . ©2018 American Association for Cancer Research.

Analyzing Cyber-Physical Threats on Robotic Platforms.

PubMed

Ahmad Yousef, Khalil M; AlMajali, Anas; Ghalyon, Salah Abu; Dweik, Waleed; Mohd, Bassam J

2018-05-21

Robots are increasingly involved in our daily lives. Fundamental to robots are the communication link (or stream) and the applications that connect the robots to their clients or users. Such communication link and applications are usually supported through client/server network connection. This networking system is amenable of being attacked and vulnerable to the security threats. Ensuring security and privacy for robotic platforms is thus critical, as failures and attacks could have devastating consequences. In this paper, we examine several cyber-physical security threats that are unique to the robotic platforms; specifically the communication link and the applications. Threats target integrity, availability and confidential security requirements of the robotic platforms, which use MobileEyes/arnlServer client/server applications. A robot attack tool (RAT) was developed to perform specific security attacks. An impact-oriented approach was adopted to analyze the assessment results of the attacks. Tests and experiments of attacks were conducted in simulation environment and physically on the robot. The simulation environment was based on MobileSim; a software tool for simulating, debugging and experimenting on MobileRobots/ActivMedia platforms and their environments. The robot platform PeopleBot TM was used for physical experiments. The analysis and testing results show that certain attacks were successful at breaching the robot security. Integrity attacks modified commands and manipulated the robot behavior. Availability attacks were able to cause Denial-of-Service (DoS) and the robot was not responsive to MobileEyes commands. Integrity and availability attacks caused sensitive information on the robot to be hijacked. To mitigate security threats, we provide possible mitigation techniques and suggestions to raise awareness of threats on the robotic platforms, especially when the robots are involved in critical missions or applications.

Analyzing Cyber-Physical Threats on Robotic Platforms †

PubMed Central

2018-01-01

Robots are increasingly involved in our daily lives. Fundamental to robots are the communication link (or stream) and the applications that connect the robots to their clients or users. Such communication link and applications are usually supported through client/server network connection. This networking system is amenable of being attacked and vulnerable to the security threats. Ensuring security and privacy for robotic platforms is thus critical, as failures and attacks could have devastating consequences. In this paper, we examine several cyber-physical security threats that are unique to the robotic platforms; specifically the communication link and the applications. Threats target integrity, availability and confidential security requirements of the robotic platforms, which use MobileEyes/arnlServer client/server applications. A robot attack tool (RAT) was developed to perform specific security attacks. An impact-oriented approach was adopted to analyze the assessment results of the attacks. Tests and experiments of attacks were conducted in simulation environment and physically on the robot. The simulation environment was based on MobileSim; a software tool for simulating, debugging and experimenting on MobileRobots/ActivMedia platforms and their environments. The robot platform PeopleBotTM was used for physical experiments. The analysis and testing results show that certain attacks were successful at breaching the robot security. Integrity attacks modified commands and manipulated the robot behavior. Availability attacks were able to cause Denial-of-Service (DoS) and the robot was not responsive to MobileEyes commands. Integrity and availability attacks caused sensitive information on the robot to be hijacked. To mitigate security threats, we provide possible mitigation techniques and suggestions to raise awareness of threats on the robotic platforms, especially when the robots are involved in critical missions or applications. PMID:29883403

Nuclear delivery of a therapeutic peptide by long circulating pH-sensitive liposomes: benefits over classical vesicles.

PubMed

Ducat, E; Deprez, J; Gillet, A; Noël, A; Evrard, B; Peulen, O; Piel, G

2011-11-28

The purpose of this study is to propose a suitable vector combining increased circulation lifetime and intracellular delivery capacities for a therapeutic peptide. Long circulating classical liposomes [SPC:CHOL:PEG-750-DSPE (47:47:6 molar% ratio)] or pH-sensitive stealth liposomes [DOPE:CHEMS:CHOL:PEG(750)-DSPE (43:21:30:6 molar% ratio)] were used to deliver a therapeutic peptide to its nuclear site of action. The benefit of using stealth pH-sensitive liposomes was investigated and formulations were compared to classical liposomes in terms of size, shape, charge, encapsulation efficiency, stability and, most importantly, in terms of cellular uptake. Confocal microscopy and flow cytometry were used to evaluate the intracellular fate of liposomes themselves and of their hydrophilic encapsulated material. Cellular uptake of peptide-loaded liposomes was also investigated in three cell lines: Hs578t human epithelial cells from breast carcinoma, MDA-MB-231 human breast carcinoma cells and WI-26 human diploid lung fibroblast cells. The difference between formulations in terms of peptide delivery from the endosome to the cytoplasm and even to the nucleus was investigated as a function of time. Characterization studies showed that both formulations possess acceptable size, shape and encapsulation efficiency but cellular uptake studies showed the important benefit of the pH-sensitive formulation over the classical one, in spite of liposome PEGylation. Indeed, stealth pH-sensitive liposomes were able to deliver hydrophilic materials strongly to the cytoplasm. Most importantly, when encapsulated in pH-sensitive stealth liposomes, the peptide was able to reach the nucleus of tumorigenic and non tumorigenic breast cancer cells. Copyright © 2011 Elsevier B.V. All rights reserved.

Security Enhanced Anonymous Multiserver Authenticated Key Agreement Scheme Using Smart Cards and Biometrics

PubMed Central

Choi, Younsung; Nam, Junghyun; Lee, Donghoon; Kim, Jiye; Jung, Jaewook; Won, Dongho

2014-01-01

An anonymous user authentication scheme allows a user, who wants to access a remote application server, to achieve mutual authentication and session key establishment with the server in an anonymous manner. To enhance the security of such authentication schemes, recent researches combined user's biometrics with a password. However, these authentication schemes are designed for single server environment. So when a user wants to access different application servers, the user has to register many times. To solve this problem, Chuang and Chen proposed an anonymous multiserver authenticated key agreement scheme using smart cards together with passwords and biometrics. Chuang and Chen claimed that their scheme not only supports multiple servers but also achieves various security requirements. However, we show that this scheme is vulnerable to a masquerade attack, a smart card attack, a user impersonation attack, and a DoS attack and does not achieve perfect forward secrecy. We also propose a security enhanced anonymous multiserver authenticated key agreement scheme which addresses all the weaknesses identified in Chuang and Chen's scheme. PMID:25276847

Thermal Image Measurements of Infrared Signatures

DTIC Science & Technology

1986-12-01

110A𔃾 (mItm D#Ie. gnea.od Block 19 contd. "ý-been shown to var,% bc.th positively and negatively comparedwith the thermometric tem"h perature...This effective temperature difference has been shown to vary both positively and negatively compared with the thermometric temperature difference... thermometric temperature difference is no longer a good representation of the radiance contrast. An "effective temperature difference" can however be defined

Security enhanced multi-factor biometric authentication scheme using bio-hash function

PubMed Central

Lee, Youngsook; Moon, Jongho

2017-01-01

With the rapid development of personal information and wireless communication technology, user authentication schemes have been crucial to ensure that wireless communications are secure. As such, various authentication schemes with multi-factor authentication have been proposed to improve the security of electronic communications. Multi-factor authentication involves the use of passwords, smart cards, and various biometrics to provide users with the utmost privacy and data protection. Cao and Ge analyzed various authentication schemes and found that Younghwa An’s scheme was susceptible to a replay attack where an adversary masquerades as a legal server and a user masquerading attack where user anonymity is not provided, allowing an adversary to execute a password change process by intercepting the user’s ID during login. Cao and Ge improved upon Younghwa An’s scheme, but various security problems remained. This study demonstrates that Cao and Ge’s scheme is susceptible to a biometric recognition error, slow wrong password detection, off-line password attack, user impersonation attack, ID guessing attack, a DoS attack, and that their scheme cannot provide session key agreement. Then, to address all weaknesses identified in Cao and Ge’s scheme, this study proposes a security enhanced multi-factor biometric authentication scheme and provides a security analysis and formal analysis using Burrows-Abadi-Needham logic. Finally, the efficiency analysis reveals that the proposed scheme can protect against several possible types of attacks with only a slightly high computational cost. PMID:28459867

Reconstructed imaging of acoustic cloak using time-lapse reversal method

NASA Astrophysics Data System (ADS)

Zhou, Chen; Cheng, Ying; Xu, Jian-yi; Li, Bo; Liu, Xiao-jun

2014-08-01

We proposed and investigated a solution to the inverse acoustic cloak problem, an anti-stealth technology to make cloaks visible, using the time-lapse reversal (TLR) method. The TLR method reconstructs the image of an unknown acoustic cloak by utilizing scattered acoustic waves. Compared to previous anti-stealth methods, the TLR method can determine not only the existence of a cloak but also its exact geometric information like definite shape, size, and position. Here, we present the process for TLR reconstruction based on time reversal invariance. This technology may have potential applications in detecting various types of cloaks with different geometric parameters.

Determination of Stability and Control Derivatives using Computational Fluid Dynamics and Automatic Differentiation

NASA Technical Reports Server (NTRS)

Park, Michael A.; Green, Lawrence L.; Montgomery, Raymond C.; Raney, David L.

1999-01-01

With the recent interest in novel control effectors there is a need to determine the stability and control derivatives of new aircraft configurations early in the design process. These derivatives are central to most control law design methods and would allow the determination of closed-loop control performance of the vehicle. Early determination of the static and dynamic behavior of an aircraft may permit significant improvement in configuration weight, cost, stealth, and performance through multidisciplinary design. The classical method of determining static stability and control derivatives - constructing and testing wind tunnel models - is expensive and requires a long lead time for the resultant data. Wind tunnel tests are also limited to the preselected control effectors of the model. To overcome these shortcomings, computational fluid dynamics (CFD) solvers are augmented via automatic differentiation, to directly calculate the stability and control derivatives. The CFD forces and moments are differentiated with respect to angle of attack, angle of sideslip, and aircraft shape parameters to form these derivatives. A subset of static stability and control derivatives of a tailless aircraft concept have been computed by two differentiated inviscid CFD codes and verified for accuracy with central finite-difference approximations and favorable comparisons to a simulation database.

Efficiency and security problems of anonymous key agreement protocol based on chaotic maps

NASA Astrophysics Data System (ADS)

Yoon, Eun-Jun

2012-07-01

In 2011, Niu-Wang proposed an anonymous key agreement protocol based on chaotic maps in [Niu Y, Wang X. An anonymous key agreement protocol based on chaotic maps. Commun Nonlinear Sci Simulat 2011;16(4):1986-92]. Niu-Wang's protocol not only achieves session key agreement between a server and a user, but also allows the user to anonymously interact with the server. Nevertheless, this paper points out that Niu-Wang's protocol has the following efficiency and security problems: (1) The protocol has computational efficiency problem when a trusted third party decrypts the user sending message. (2) The protocol is vulnerable to Denial of Service (DoS) attack based on illegal message modification by an attacker.

On symmetry inheritance of nonminimally coupled scalar fields

NASA Astrophysics Data System (ADS)

Barjašić, Irena; Smolić, Ivica

2018-04-01

We present the first symmetry inheritance analysis of fields non-minimally coupled to gravity. In this work we are focused on the real scalar field ϕ with nonminimal coupling of the form ξφ2 R . Possible cases of symmetry noninheriting fields are constrained by the properties of the Ricci tensor and the scalar potential. Examples of such spacetimes can be found among those which are ‘dressed’ with the stealth scalar field, a nontrivial scalar field configuration with the vanishing energy–momentum tensor. We classify the scalar field potentials which allow symmetry noninheriting stealth field configurations on top of the exact solutions of the Einstein’s gravitational field equation with the cosmological constant.

Comparing Reactivation Behavior of TIG and Laser Beam Welded Alloy 690

NASA Astrophysics Data System (ADS)

Abraham, Geogy J.; Bhambroo, Rajan; Kain, V.; Dey, G. K.; Raja, V. S.

2013-02-01

The nickel base Alloy 690 was subjected to simulated autogenous welding treatment employing two different techniques, laser beam welding (LBW) and tungsten inert gas (TIG) welding. The resultant weld fusion zone (WFZ) and heat-affected zone (HAZ) were compared by studying the reactivation behavior. The chromium depletion effect was assessed by measuring the degree of sensitization (DOS) from the electrochemical potentiodynamic reactivation (EPR) test. A double-loop EPR test for Alloy 690 was employed to measure the DOS at different regions of weldments by masking the remaining regions. The results clearly demonstrated that Alloy 690 showed no sensitization in the parent material and the WFZ region of both TIG and laser weldments. However, it exhibited reactivation in the HAZ region of both the weldments. The DOS values measured for Alloy 690 were very low for all the regions of the LBW weldment as compared to that in the TIG weldment. The HAZ region of the LBW weldment showed the highest DOS value in any region of the weldment but even this value was quite low indicating absence of sensitization in LBW weldment. The attack along the grain boundaries for the weldments after EPR experiments were studied using optical and scanning electron microscopy.

ET AAS evaluation of the stability and pH-sensitivity of, pH-sensitive stealth liposomes containing cisplatin in mouse plasma.

PubMed

Vieira, F P; Mesquita, T L; Lara, P C P; Ramaldes, G A; Beinner, M A; Silva, J B B; Oliveira, M C; Silveira, J N

2013-10-01

In this work, stability and the pH-sensitivity of pH-sensitive stealth liposomes containing cisplatin exposed to plasma medium and their subsequent responses to pH modifications were evaluated. A method to determine platin in mouse plasma by electrothermal atomic absorption spectroscopy (ET AAS) was developed and validated. At first, a comparative study of sample preparation treatments with basic, acidic, and acidic added with Triton X-100 as a modifier was done. The best treatment was obtained with HCl 3% (v/v). The ET AAS method with acid treatment presented linearity at a range of 10-160 ng Pt/mL. The limits of detection (LOD) was 3.1 ng/mL Pt for acid treatment, while the limit quantification (LOQ) was 10 ng/mL Pt. The acid treatment presented good repeatability (VC<15.0%) and recovery close to 100%. This treatment was chosen for subsequent studies due to its best value of repeatability, recovery, LOD and lowest cost. pH-sensitive stealth liposomes, containing cisplatin, demonstrated low stability and poor response to pH variation after plasma incubation. These findings suggest that further studies are needed to improve liposome formulation i.e., to reduce its size. Copyright © 2013 Elsevier B.V. All rights reserved.

Biodistribution and pharmacokinetics of In-111-labeled Stealth{reg_sign} liposomes in patients with solid tumours

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrington, K.J.; Peters, A.M.; Mohammadtaghi, S.

1996-05-01

The use of liposomal doxorubicin yields response rates of up to 70-80% in patients with AIDS-related Kaposi`s sarcoma with favourable alteration of the toxicity profile of the drug. Liposomal delivery of therapy in patients with solid cancers is currently under investigation. Our aim is to determine the biodistribution and pharmacokinetics of In-111-labeled Stealth{reg_sign} liposomes (SEQUUS{trademark}) liposomes (SEQUUS{trademark} Pharmaceuticals Inc., Menlo Park, USA) in patients with advanced solid malignant tumours. Ten patients (4 male, 6 female) with a median age of 59 (range 43 - 75) received 100 MBq of In-111-labeled Stealth{reg_sign} liposomes. Four had breast cancer, 3 head and neckmore » tumours, 2 lung and 1 cervical cancer. Blood samples and whole body gamma camera images were obtained at 0.5, 4, 24, 48, 72, 96 and 240 hours after injection and sequential 24 hour urine collections were performed for the first 96 h. SPECT imaging was performed when indicated. High definition images of tumours were obtained in 9 patients (3/4 breast, 3/3 head and neck, 2/2 lung and 1/1 cervix cancers). One patient (breast cancer) had negative images. The median cumulative urinary excretion of In-111 over the first 96 h was 17.8 (range 3.5-21.3) % of the injected dose. The uptake of liposomes in various tissues was estimated from regions of interest on the whole body images. Prominent uptake was seen in the liver (10-15% of injected dose), lungs (4-9%) and spleen (2-8%). Tumour uptake in the first 96 h varied form 0.5-4% of the injected dose. This is approximately 10 fold higher than might be expected from experience with other targeting methods (eg monoclonal antibodies). These data confirm that Stealth liposomes have a prolonged circulation half-life and localise to solid tumour tissue.« less

Lights on: Dye dequenching reveals polymersome fusion with polymer, lipid and stealth lipid vesicles

DOE PAGES

Henderson, Ian M.; Collins, Aaron M.; Quintana, Hope A.; ...

2015-12-13

In this study, we develop a quantitative dye dequenching technique for the measurement of polymersome fusion, using it to characterize the salt mediated, mechanically-induced fusion of polymersomes with polymer, lipid, and so-called stealth lipid vesicles. While dye dequenching has been used to quantitatively explore liposome fusion in the past, this is the first use of dye dequenching to measure polymersome fusion of which we are aware. In addition to providing quantitative results, dye dequenching is ideal for detecting fusion in instances where DLS results would be ambiguous, such as low yield levels and size ranges outside the capabilities of DLS.more » The dye chosen for this study was a cyanine derivative, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR), which proved to provide excellent data on the extent of polymersome fusion. Using this technique, we have shown the limited fusion capabilities of polymersome/liposome heterofusion, notably DOPC vesicles fusing with polymersomes at half the efficiency of polymersome homofusion and DPPC vesicles showing virtually no fusion. In addition to these key heterofusion experiments, we determined the broad applicability of dye dequenching in measuring kinetic rates of polymersome fusion; and showed that even at elevated temperatures or over multiple weeks' time, no polymersome fusion occurred without agitation. Stealth liposomes formed from DPPC and PEO-functionalized lipid, however, fused with polymersomes and stealth liposomes with relatively high efficiency, lending support to our hypothesis that the response of the PEO corona to salt is a key factor in the fusion process. This last finding suggests that although the conjugation of PEO to lipids increases vesicle biocompatibility and enables their longer circulation times, it also renders the vesicles subject to destabilization under high salt and shear (e.g. in the circulatory system) that may lead to, in this case, fusion.« less

Planet Earth: Its Past, Our Present, A Future (?)

NASA Astrophysics Data System (ADS)

Kieffer, S. W.

2012-04-01

We who have lived through the second half of the 20th century into the 21st century have witnessed a profound transition in the biological and physical relationship between humans and the rest of the planet. In the middle of the last century, our planet still had undeveloped islands: there were frontiers that held new lands, mysteries, adventures, cultures, and resources. However, these islands have merged into a relatively seamless planet by a mobile and expanding population, science and technology, and global communication. We are subject to stealth as well as natural disasters. Natural disasters result from the ongoing geological and meteorological processes on our planet, increasingly exacerbated by human presence and behavior. Stealth disasters, on the other hand, are caused by humans, but involve the natural systems that support us. Examples of stealth disasters are climate change, loss of soils, acidification of the oceans, desertification, and loss of groundwater resources. Civilization is a complex system. It has emergent properties, and a tuning parameter--a parameter that is "tuned" until the unexpected happens. The tuning parameter for populations is the number of members relative to the capacities that support them. Because of our sheer numbers, we are driving the stealth disasters, and we will be affected more severely by natural disasters than we have been in the past on a less densely populated planet. To guide our thinking about geoethical issues, we propose a (hypothetical) world organization modeled after the Centers for Disease Control (CDC) in the U.S., and call it the Center for Disaster Control for Planet Earth (CDCPE). This center would have a scientific body to provide impartial facts and uncertainties, an engineering body to propose and implement technical solutions, a negotiating body to balance the realities of political, economic, religious and cultural values, and an enforcement body that is responsive to all of the inputs. How shall we start?

Stealth Disasters and Geoethics

NASA Astrophysics Data System (ADS)

Kieffer, Susan W.

2013-04-01

Natural processes of the earth unleash energy in ways that are sometimes harmful or, at best, inconvenient, for humans: earthquakes, volcanic eruptions, hurricanes, landslides, floods. Ignoring the biological component of the geosphere, we have historically called such events "natural disasters." They are typically characterized by a sudden onset and relatively immediate consequences. There are many historical examples and our human societies have evolved various ways of coping with them logistically, economically, and psychologically. Preparation, co-existence, recovery, and remediation are possible, at least to some extent, even in the largest of events. Geoethical questions exist in each stage, but the limited local extent of these disasters allows the possibility of discussion and resolution. There are other disasters that involve the natural systems that support us. Rather than being driven primarily by natural non-biological processes, these are driven by human behavior. Examples are climate change, desertification, acidification of the oceans, and compaction and erosion of fertile soils. They typically have more gradual onsets than natural disasters and, because of this, I refer to these as "stealth disasters." Although they are unfolding unnoticed or ignored by many, they are having near-term consequences. At a global scale they are new to human experience. Our efforts at preparation, co-existence, recovery, and remediation lag far behind those that we have in place for natural disasters. Furthermore, these four stages in stealth disaster situations involve many ethical questions that typically must be solved in the context of much larger cultural and social differences than encountered in natural disaster settings. Four core ethical principles may provide guidelines—autonomy, non-maleficence, beneficence, and justice (e.g., Jamais Cascio). Geoscientists can contribute to the solutions in many ways. We can work to ensure that as people take responsibility for their own lives (autonomy), they have relevant information in useable form. To minimize harm to others and the environment (non-maleficence), we can design and implement sustainable ways to extract resources and dispose of waste. To advance the welfare of humankind (beneficence), we can work with engineers on innovative uses for commodities that are easily-obtained, and on replacements for rare ones. And, we can strive toward social justice by recognizing that social, ethical, legal and political issues regarding resource use may be far more difficult than the geotechnical ones, and work within the (sometimes frustrating) framework for resolution of those issues. Referring back to the four stages of co-existence with natural disasters (preparation, co-existence, recovery, and remediation), the global scope of stealth disasters raises far more geoethical issues than we have encountered with natural disasters. Just as we have learned (e.g., Hurricanes Katrina and Sandy in the U.S.) that inter-agency response is crucial to successful management of natural disasters, we can expect that global cooperation in management and governance will be essential to the management of stealth disasters. It is imperative that research and education of current and future geoscientists in universities recognize the newly developing role of the geosciences in stealth disasters and that we train our students for a future within this context.

Design of "Eye Closure" system for the stealth of photo-electric equipments

NASA Astrophysics Data System (ADS)

Zhang, Y.; Hua, W. S.; Li, G.

2012-10-01

Based on the optical activity of liquid crystal, a new approach for the stealth of "cat's eye" targets is proposed in this paper. It imitates the physiological close reaction of human eyes when strong light irradiates eyes. With this approach, the "cat's eye" effect will vanish, which is applied in restricting photo-electric equipments being detected and located by active laser detection system. The structure and working principle of the design are presented. The drive circuit is given to control the optical switch automatically. Feasibility of this design is demonstrated by experimental method. The measured data illustrate that the proposed approach is effective to eliminate the "cat's eye" effect, so as to enhancing the viability of photo-electric equipments on the battlefield.

Defending networks against denial-of-service attacks

NASA Astrophysics Data System (ADS)

Gelenbe, Erol; Gellman, Michael; Loukas, George

2004-11-01

Denial of service attacks, viruses and worms are common tools for malicious adversarial behavior in networks. Experience shows that over the last few years several of these techniques have probably been used by governments to impair the Internet communications of various entities, and we can expect that these and other information warfare tools will be used increasingly as part of hostile behavior either independently, or in conjunction with other forms of attack in conventional or asymmetric warfare, as well as in other forms of malicious behavior. In this paper we concentrate on Distributed Denial of Service Attacks (DDoS) where one or more attackers generate flooding traffic and direct it from multiple sources towards a set of selected nodes or IP addresses in the Internet. We first briefly survey the literature on the subject, and discuss some examples of DDoS incidents. We then present a technique that can be used for DDoS protection based on creating islands of protection around a critical information infrastructure. This technique, that we call the CPN-DoS-DT (Cognitive Packet Networks DoS Defence Technique), creates a self-monitoring sub-network surrounding each critical infrastructure node. CPN-DoS-DT is triggered by a DDoS detection scheme, and generates control traffic from the objects of the DDoS attack to the islands of protection where DDOS packet flows are destroyed before they reach the critical infrastructure. We use mathematical modelling, simulation and experiments on our test-bed to show the positive and negative outcomes that may result from both the attack, and the CPN-DoS-DT protection mechanism, due to imperfect detection and false alarms.

Distinct polymer architecture mediates switching of complement activation pathways at the nanosphere-serum interface: implications for stealth nanoparticle engineering.

PubMed

Hamad, Islam; Al-Hanbali, Othman; Hunter, A Christy; Rutt, Kenneth J; Andresen, Thomas L; Moghimi, S Moein

2010-11-23

Nanoparticles with surface projected polyethyleneoxide (PEO) chains in "mushroom-brush" and "brush" configurations display stealth properties in systemic circulation and have numerous applications in site-specific targeting for controlled drug delivery and release as well as diagnostic imaging. We report on the "structure-activity" relationship pertaining to surface-immobilized PEO of various configurations on model nanoparticles, and the initiation of complement cascade, which is the most ancient component of innate human immunity, and its activation may induce clinically significant adverse reactions in some individuals. Conformational states of surface-projected PEO chains, arising from the block copolymer poloxamine 908 adsorption, on polystyrene nanoparticles trigger complement activation differently. Alteration of copolymer architecture on nanospheres from mushroom to brush configuration not only switches complement activation from C1q-dependent classical to lectin pathway but also reduces the level of generated complement activation products C4d, Bb, C5a, and SC5b-9. Also, changes in adsorbed polymer configuration trigger alternative pathway activation differently and through different initiators. Notably, the role for properdin-mediated activation of alternative pathway was only restricted to particles displaying PEO chains in a transition mushroom-brush configuration. Since nanoparticle-mediated complement activation is of clinical concern, our findings provide a rational basis for improved surface engineering and design of immunologically safer stealth and targetable nanosystems with polymers for use in clinical medicine.

Bayesian-MCMC-based parameter estimation of stealth aircraft RCS models

NASA Astrophysics Data System (ADS)

Xia, Wei; Dai, Xiao-Xia; Feng, Yuan

2015-12-01

When modeling a stealth aircraft with low RCS (Radar Cross Section), conventional parameter estimation methods may cause a deviation from the actual distribution, owing to the fact that the characteristic parameters are estimated via directly calculating the statistics of RCS. The Bayesian-Markov Chain Monte Carlo (Bayesian-MCMC) method is introduced herein to estimate the parameters so as to improve the fitting accuracies of fluctuation models. The parameter estimations of the lognormal and the Legendre polynomial models are reformulated in the Bayesian framework. The MCMC algorithm is then adopted to calculate the parameter estimates. Numerical results show that the distribution curves obtained by the proposed method exhibit improved consistence with the actual ones, compared with those fitted by the conventional method. The fitting accuracy could be improved by no less than 25% for both fluctuation models, which implies that the Bayesian-MCMC method might be a good candidate among the optimal parameter estimation methods for stealth aircraft RCS models. Project supported by the National Natural Science Foundation of China (Grant No. 61101173), the National Basic Research Program of China (Grant No. 613206), the National High Technology Research and Development Program of China (Grant No. 2012AA01A308), the State Scholarship Fund by the China Scholarship Council (CSC), and the Oversea Academic Training Funds, and University of Electronic Science and Technology of China (UESTC).

The Civil Rights Act of 1991: From Conciliation to Litigation-- How Congress Delegates Lawmaking to the Courts

DTIC Science & Technology

1993-04-01

instead of attacking the causes. The 1991 Act is a law of stratification that encourages racism , sexism , and litigation to further individual goals and...30 D. What About Those Statistics ? ............................ 31 E. Race Norming - The Dos and Don’ts of Test Scores...in Title VII to recognize group rights through a "disparate impact" theory of discrimination. In Griggs v. Duke Power Co.,` the Court recognized that

Authenticated IGMP for Controlling Access to Multicast Distribution Tree

NASA Astrophysics Data System (ADS)

Park, Chang-Seop; Kang, Hyun-Sun

A receiver access control scheme is proposed to protect the multicast distribution tree from DoS attack induced by unauthorized use of IGMP, by extending the security-related functionality of IGMP. Based on a specific network and business model adopted for commercial deployment of IP multicast applications, a key management scheme is also presented for bootstrapping the proposed access control as well as accounting and billing for CP (Content Provider), NSP (Network Service Provider), and group members.

Expanded R&D by Jet-engine-steering Revolution

NASA Astrophysics Data System (ADS)

Gal-Or, Benjamin

2017-11-01

Since 1987 [1,2,3,4,5] the global jet engine community is facing the historical fact that jet engine steering is gradually replacing canards and the common, often dangerous and obsolete, aerodynamic-only flight control - a fact that (i) has already affected the defense-industrial complex in the US, Russia, China, Japan, S-Korea and India, (ii) has integrated the traditional jet-engine components R&D with advanced aero-electro-physics, stealth technology, thrust vectoring aerodynamics and material science. Moreover, this military revolution is historically due to expand into the civil transport jets domain, [6,7,8,9]. The historical aim of the JES-Revolution remains the same: Replace the common, stall-spin sensitive canards [6] and Aerodynamic-Only-Obsolete-Flight Control ("AOOF Control"). Invented about 100 years ago for propeller-driven air vehicles, it has already been partially replaced for failure to function in WVR-combat post-stall domain, and for the following reasons: In comparison with complete Tail-Less, Canard-Less, Stealth-JES (Figure 5 and References [1,2,3,4,5,6]), the common AOOF Control increases drag, weight, fuel consumption, complexity, cost, and reduces flight safety, stealth, [Low Detectability] and provides zero post-stall, WVR air combat capability while its CANARDS KILL LD & REDUCE JES. Examples of stealth fighter aircraft that have already replaced canards and AOOF-Control where JES provides at least 64 to 0 KILL-RATIO advantage over AOOF-Controlled conventional fighter aircraft: The U.S. JES F-22 and, apparently, the Russian JES-Su-T-50 & 35S, China 2016-J-31, Indian HAL AMCA & FGFA, Japanese JES IHHI ATD-X, S-Korean JES KF-X. Cf. X-44 in Figure 5. Consequently, the jet engine is no longer defined as providing only brute force forward. Instead, it successfully competes with and wins over the wrong, dominating AOOF-Control, at least as a backup flight control whose sole factual domain is currently a well-established, primary flight controller RE any post-stall, super-agility, [2,3,4,5,6,7,8,9].

Simulated ventriculostomy training with conventional neuronavigational equipment used clinically in the operating room: prospective validation study.

PubMed

Kirkman, Matthew A; Muirhead, William; Sevdalis, Nick; Nandi, Dipankar

2015-01-01

Simulation is gaining increasing interest as a method of delivering high-quality, time-effective, and safe training to neurosurgical residents. However, most current simulators are purpose-built for simulation, being relatively expensive and inaccessible to many residents. The purpose of this study was to provide the first comprehensive validity assessment of ventriculostomy performance metrics from the Medtronic StealthStation S7 Surgical Navigation System, a neuronavigational tool widely used in the clinical setting, as a training tool for simulated ventriculostomy while concomitantly reporting on stress measures. A prospective study where participants performed 6 simulated ventriculostomy attempts on a model head with StealthStation-coregistered imaging. The performance measures included distance of the ventricular catheter tip to the foramen of Monro and presence of the catheter tip in the ventricle. Data on objective and self-reported stress and workload measures were also collected. The operating rooms of the National Hospital for Neurology and Neurosurgery, Queen Square, London. A total of 31 individuals with varying levels of prior ventriculostomy experience, varying in seniority from medical student to senior resident. Performance at simulated ventriculostomy improved significantly over subsequent attempts, irrespective of previous ventriculostomy experience. Performance improved whether or not the StealthStation display monitor was used for real-time visual feedback, but performance was optimal when it was. Further, performance was inversely correlated with both objective and self-reported measures of stress (traditionally referred to as concurrent validity). Stress and workload measures were well-correlated with each other, and they also correlated with technical performance. These initial data support the use of the StealthStation as a training tool for simulated ventriculostomy, providing a safe environment for repeated practice with immediate feedback. Although the potential implications are profound for neurosurgical education and training, further research following this proof-of-concept study is required on a larger scale for full validation and proof that training translates into improved long-term simulated and patient outcomes. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Advancing Global Health - The Need for (Better) Social Science Comment on "Navigating Between Stealth Advocacy and Unconscious Dogmatism: The Challenge of Researching the Norms, Politics and Power of Global Health".

PubMed

Hanefeld, Johanna

2016-02-06

In his perspective "Navigating between stealth advocacy and unconscious dogmatism: the challenge of researching the norms, politics and power of global health," Ooms argues that actions taken in the field of global health are dependent not only on available resources, but on the normative premise that guides how these resources are spent. This comment sets out how the application of a predominately biomedical positivist research tradition in global health, has potentially limited understanding of the value judgements underlying decisions in the field. To redress this critical social science, including health policy analysis has much to offer, to the field of global health including on questions of governance. © 2016 by Kerman University of Medical Sciences.

Cancer Self-Defense: An Immune Stealth.

PubMed

Nakajima, Kosei; Nangia-Makker, Pratima; Hogan, Victor; Raz, Avraham

2017-10-15

The hurdles in realizing successful cancer immunotherapy stem from the fact that cancer patients are either refractory to immune response and/or develop resistance. Here, we propose that these phenomena are due, in part, to the deployment/secretion of a "decoy flare," for example, anomalous cancer-associated antigens by the tumor cells. The cancer secretome, which resembles the parent cell make-up, is composed of soluble macromolecules (proteins, glycans, lipids, DNAs, RNAs, etc.) and insoluble vesicles (exosomes), thus hindering cancer detection/recognition by immunotherapeutic agents, resulting in a "cancer-stealth" effect. Immunotherapy, or any treatment that relies on antigens' expression/function, could be improved by the understanding of the properties of the cancer secretome, as its clinical evaluation may change the therapeutic landscape. Cancer Res; 77(20); 5441-4. ©2017 AACR . ©2017 American Association for Cancer Research.

Identification of Low Coronal Sources of “Stealth” Coronal Mass Ejections Using New Image Processing Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alzate, Nathalia; Morgan, Huw, E-mail: naa19@aber.ac.uk

Coronal mass ejections (CMEs) are generally associated with low coronal signatures (LCSs), such as flares, filament eruptions, extreme ultraviolet (EUV) waves, or jets. A number of recent studies have reported the existence of stealth CMEs as events without LCSs, possibly due to observational limitations. Our study focuses on a set of 40 stealth CMEs identified from a study by D’Huys et al. New image processing techniques are applied to high-cadence, multi-instrument sets of images spanning the onset and propagation time of each of these CMEs to search for possible LCSs. Twenty-three of these events are identified as small, low-mass, unstructuredmore » blobs or puffs, often occurring in the aftermath of a large CME, but associated with LCSs such as small flares, jets, or filament eruptions. Of the larger CMEs, seven are associated with jets and eight with filament eruptions. Several of these filament eruptions are different from the standard model of an erupting filament/flux tube in that they are eruptions of large, faint flux tubes that seem to exist at large heights for a long time prior to their slow eruption. For two of these events, we see an eruption in Large Angle Spectrometric Coronagraph C2 images and the consequent changes at the bottom edge of the eruption in EUV images. All 40 events in our study are associated with some form of LCS. We conclude that stealth CMEs arise from observational and processing limitations.« less

Stealth properties of poly(ethylene oxide)-based triblock copolymer micelles: a prerequisite for a pH-triggered targeting system.

PubMed

Van Butsele, K; Morille, M; Passirani, C; Legras, P; Benoit, J P; Varshney, S K; Jérôme, R; Jérôme, C

2011-10-01

Evaluation of the biocompatibility of pH-triggered targeting micelles was performed with the goal of studying the effect of a poly(ethylene oxide) (PEO) coating on micelle stealth properties. Upon protonation under acidic conditions, pH-sensitive poly(2-vinylpyridine) (P2VP) blocks were stretched, exhibiting positive charges at the periphery of the micelles as well as being a model targeting unit. The polymer micelles were based on two different macromolecular architectures, an ABC miktoarm star terpolymer and an ABC linear triblock copolymer, which combined three different polymer blocks, i.e. hydrophobic poly(ε-caprolactone), PEO and P2VP. Neutral polymer micelles were formed at physiological pH. These systems were tested for their ability to avoid macrophage uptake, their complement activation and their pharmacological behavior after systemic injection in mice, as a function of their conformation (neutral or protonated). After protonation, complement activation and macrophage uptake were up to twofold higher than for neutral systems. By contrast, when P2VP blocks and the targeting unit were buried by the PEO shell at physiological pH, micelle stealth properties were improved, allowing their future systemic injection with an expected long circulation in blood. Smart systems responsive to pH were thus developed which therefore hold great promise for targeted drug delivery to an acidic tumoral environment. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

IDMA: improving the defense against malicious attack for mobile ad hoc networks based on ARIP protocol

NASA Astrophysics Data System (ADS)

Peng, Chaorong; Chen, Chang Wen

2008-04-01

Malicious nodes are mounting increasingly sophisticated attacking operations on the Mobile Ad Hoc Networks (MANETs). This is mainly because the IP-based MANETs are vulnerable to attacks by various malicious nodes. However, the defense against malicious attack can be improved when a new layer of network architecture can be developed to separate true IP address from disclosing to the malicious nodes. In this paper, we propose a new algorithm to improve the defense against malicious attack (IDMA) that is based on a recently developed Assignment Router Identify Protocol (ARIP) for the clustering-based MANET management. In the ARIP protocol, we design the ARIP architecture based on the new Identity instead of the vulnerable IP addresses to provide the required security that is embedded seamlessly into the overall network architecture. We make full use of ARIP's special property to monitor gateway forward packets by Reply Request Route Packets (RREP) without additional intrusion detection layer. We name this new algorithm IDMA because of its inherent capability to improve the defense against malicious attacks. Through IDMA, a watching algorithm can be established so as to counterattack the malicious node in the routing path when it unusually drops up packets. We provide analysis examples for IDMA for the defense against a malicious node that disrupts the route discovery by impersonating the destination, or by responding with state of corrupted routing information, or by disseminating forged control traffic. The IDMA algorithm is able to counterattack the malicious node in the cases when the node lunch DoS attack by broadcast a large number of route requests, or make Target traffic congestion by delivering huge mount of data; or spoof the IP addresses and send forge packets with a fake ID to the same Target causing traffic congestion at that destination. We have implemented IDMA algorism using the GloMoSim simulator and have demonstrated its performance under a variety of operational conditions.

A study of IEEE 802.15.4 security framework for wireless body area networks.

PubMed

Saleem, Shahnaz; Ullah, Sana; Kwak, Kyung Sup

2011-01-01

A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.

A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Networks

PubMed Central

Saleem, Shahnaz; Ullah, Sana; Kwak, Kyung Sup

2011-01-01

A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN. PMID:22319358

A DHS Skunkworks Project: Defining and Addressing Homeland Security Grand Challenges

DTIC Science & Technology

2016-12-01

Peter Diamandis, Ansari XPRIZE, market failure, technology, stealth technologies, Pasteur’s quadrant, Heilmeier Catechism, Homeland Security Advanced...Judging and Scoring ....................................................................27 D. OPTIMIZING FOR AN EMERGING MARKET ...37 Figure 3. Market /Technology Chart

Water-injected all-dielectric ultra-wideband and prominent oblique incidence metamaterial absorber in microwave regime

NASA Astrophysics Data System (ADS)

Huang, Xiaojun; Yang, Helin; Shen, Zhaoyang; Chen, Jiao; Lin, Hail; Yu, Zetai

2017-09-01

We present a water-injected all-dielectric metamaterial that can offer an extremely wide bandwidth of electromagnetic absorption and prominent wide incident angle range. Different from conventional metal-dielectric based metamaterial absorbers, the absorption mechanism of the proposed all-dielectric metamaterial absorber is to take advantage of the dispersion of water, rather than electric or/and magnetic resonance, which thoroughly overcomes the defects of narrow bandwidth and oblique incidence from metal-dielectric based metamaterial absorber. The simulated absorption was over 90% in 8.1-22.9 GHz with the relative bandwidth of 95.5% when the incident angle reaches 60°, and the corresponding microwave experiment is performed to support the simulations. The obtained excellent absorption performance reveals a possible application of the proposed absorber, which can be exploited for electromagnetic stealth purposes, especially for electromagnetic stealth of sea targets.

Time-of-Flight Microwave Camera.

PubMed

Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

2015-10-05

Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable "stealth" regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows "camera-like" behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum.

'Stealth' nanoparticles evade neural immune cells but also evade major brain cell populations: Implications for PEG-based neurotherapeutics.

PubMed

Jenkins, Stuart I; Weinberg, Daniel; Al-Shakli, Arwa F; Fernandes, Alinda R; Yiu, Humphrey H P; Telling, Neil D; Roach, Paul; Chari, Divya M

2016-02-28

Surface engineering to control cell behavior is of high interest across the chemical engineering, drug delivery and biomaterial communities. Defined chemical strategies are necessary to tailor nanoscale protein interactions/adsorption, enabling control of cell behaviors for development of novel therapeutic strategies. Nanoparticle-based therapies benefit from such strategies but particle targeting to sites of neurological injury remains challenging due to circulatory immune clearance. As a strategy to overcome this barrier, the use of stealth coatings can reduce immune clearance and prolong circulatory times, thereby enhancing therapeutic capacity. Polyethylene glycol (PEG) is the most widely-used stealth coating and facilitates particle accumulation in the brain. However, once within the brain, the mode of handling of PEGylated particles by the resident immune cells of the brain itself (the 'microglia') is unknown. This is a critical question as it is well established that microglia avidly sequester nanoparticles, limiting their bioavailability and posing a major translational barrier. If PEGylation can be proved to promote evasion of microglia, then this information will be of high value in developing tailored nanoparticle-based therapies for neurological applications. Here, we have conducted the first comparative study of uptake of PEGylated particles by all the major (immune and non-immune) brain cell types. We prove for the first time that PEGylated nanoparticles evade major brain cell populations - a phenomenon which will enhance extracellular bioavailability. We demonstrate changes in protein coronas around these particles within biological media, and discuss how surface chemistry presentation may affect this process and subsequent cellular interactions. Copyright © 2016 Elsevier B.V. All rights reserved.

Balancing stealth and echogenic properties in an ultrasound contrast agent with drug delivery potential.

PubMed

Jablonowski, Lauren J; Alfego, David; Andorko, James I; Eisenbrey, John R; Teraphongphom, Nutte; Wheatley, Margaret A

2016-10-01

Contrast agents are currently being modified to combine diagnostic and therapeutic capabilities. For ultrasound (US) imaging with polymeric contrast agents, it is necessary to modify the shell to create "stealth" microbubbles but without these modifications sacrificing the agent's ability to interact with the focused US beam. We hypothesize that addition of the classic immune shielding molecule polyethylene glycol (PEG) to a polylactide (PLA) microbubble shell will affect the acoustic and physical properties of the resulting agents. In an effort to determine the best formulation to achieve a balance between stealth and acoustic activity, we compared two PEGylation techniques; addition of increasing amounts of PEG-PLA copolymer and employing incorporation of a PEG lipid (LipidPEG) into the shell. Loss of acoustic enhancement occurred in a dose-dependent manner for both types of PEGylated agents (loss of signal occurred at >5 wt% PEG-PLA and >1 wt% LipidPEG), while immune activation was also reduced in a dose-dependent manner for the PEG-PLA agents. This study shows that the balance between acoustic behavior and improved immune avoidance was scalable and successful to different degrees with both PEGylation methods, and was best achieved using for PEG-PLA at 5 wt% and for LipidPEG at 1 wt%. Studies are ongoing to evaluate the best method for the targeting and drug delivery capabilities of these agents for applications in cancer treatment. This study represents the basis for understanding the consequences of making modifications to the native polymeric shell. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Other Intelligences (Oy Vey!).

ERIC Educational Resources Information Center

Chase, Kim

1998-01-01

A middle-school teacher humorously observes seven other intelligences of students: random thinking; virtual memory void (erasing entire sections of personal memory); antigravity (balancing on two chair legs); intravacancy (achieving perfect, effortless aplomb); inter-Origami (intricate note-folding); stealth-kinesthetic (peashooting spitballs…

Research for new UAV capabilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canavan, G.H.; Leadabrand, R.

1996-07-01

This paper discusses research for new Unmanned Aerial Vehicles (UAV) capabilities. Findings indicate that UAV performance could be greatly enhanced by modest research. Improved sensors and communications enhance near term cost effectiveness. Improved engines, platforms, and stealth improve long term effectiveness.

Novel Targeting Approach for Breast Cancer Gene Therapy

DTIC Science & Technology

2009-09-30

specificity of sigma receptor ligands ( haloperidol and ibogaine)- conjugated polyamidoamine (PAMAM) dendrimers 1. Synthesis, purification and...Heparanase promoter. Cancer Lett., 2006, 240, 114-122. 5. Mukherjee A, Prasad TK, Rao NM, Banerjee R. Haloperidol associated stealth liposomes: A

Control of submersible vortex flows

NASA Technical Reports Server (NTRS)

Bushnell, D. M.; Donaldson, C. D.

1990-01-01

Vortex flows produced by submersibles typically unfavorably influence key figures of merit such as acoustic and nonacoustic stealth, control effectiveness/maneuverability, and propulsor efficiency/body drag. Sources of such organized, primarily longitudinal, vorticity include the basic body (nose and sides) and appendages (both base/intersection and tip regions) such as the fairwater, dive planes, rear control surfaces, and propulsor stators/tips. Two fundamentally different vortex control approaches are available: (1) deintensification of the amplitude and/or organization of the vortex during its initiation process; and (2) downstream vortex disablement. Vortex control techniques applicable to the initiation region (deintensification approach) include transverse pressure gradient minimization via altered body cross section, appendage dillets, fillets, and sweep, and various appendage tip and spanload treatment along with the use of active controls to minimize control surface size and motions. Vortex disablement can be accomplished either via use of control vortices (which can also be used to steer the vortices off-board), direct unwinding, inducement of vortex bursting, or segmentation/tailoring for enhanced dissipation. Submersible-applicable vortex control technology is also included derived from various aeronautical applications such as mitigation of the wing wake vortex hazard and flight aircraft maneuverability at high angle of attack as well as the status of vortex effects upon, and mitigation of, nonlinear control forces on submersibles. Specific suggestions for submersible-applicable vortex control techniques are presented.

Summary of ongoing TARDEC Work in Metamaterials Relevant to NATO SET-181

DTIC Science & Technology

2013-08-21

Meitzler, T., Bankowski, E., Tiberkevich, T., and Slavin, A., Book Chapter on Spin-Torque Microwave Detectors, Magnonics - From Fundamentals to...harvesting - spintronic metamaterials; Non-reciprocity without magnetic field – magnonic metamaterials; Stealth and cloaking – optical metamaterials.

Novel Targeting Approach for Breast Cancer Gene Therapy

DTIC Science & Technology

2010-09-01

haloperidol and ibogaine)- conjugated polyamidoamine (PAMAM) dendrimers Poly(amidoamine) (PAMAM) dendrimers of 3.5 generation with carboxylate surface...Mukherjee A, Prasad TK, Rao NM, Banerjee R. Haloperidol associated stealth liposomes. A potent carrier for delivering genes to human breast cancer cells

40 CFR 94.908 - National security exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.908 National security exemption. (a)(1) Any marine engine, otherwise subject to this part, that is... armor, permanently affixed weaponry, specialized electronic warfare systems, unique stealth performance...

40 CFR 94.908 - National security exemption.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.908 National security exemption. (a)(1) Any marine engine, otherwise subject to this part, that is... armor, permanently affixed weaponry, specialized electronic warfare systems, unique stealth performance...

40 CFR 94.908 - National security exemption.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.908 National security exemption. (a)(1) Any marine engine, otherwise subject to this part, that is... armor, permanently affixed weaponry, specialized electronic warfare systems, unique stealth performance...

40 CFR 94.908 - National security exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.908 National security exemption. (a)(1) Any marine engine, otherwise subject to this part, that is... armor, permanently affixed weaponry, specialized electronic warfare systems, unique stealth performance...

40 CFR 94.908 - National security exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.908 National security exemption. (a)(1) Any marine engine, otherwise subject to this part, that is... armor, permanently affixed weaponry, specialized electronic warfare systems, unique stealth performance...

FSM-F: Finite State Machine Based Framework for Denial of Service and Intrusion Detection in MANET.

PubMed

N Ahmed, Malik; Abdullah, Abdul Hanan; Kaiwartya, Omprakash

2016-01-01

Due to the continuous advancements in wireless communication in terms of quality of communication and affordability of the technology, the application area of Mobile Adhoc Networks (MANETs) significantly growing particularly in military and disaster management. Considering the sensitivity of the application areas, security in terms of detection of Denial of Service (DoS) and intrusion has become prime concern in research and development in the area. The security systems suggested in the past has state recognition problem where the system is not able to accurately identify the actual state of the network nodes due to the absence of clear definition of states of the nodes. In this context, this paper proposes a framework based on Finite State Machine (FSM) for denial of service and intrusion detection in MANETs. In particular, an Interruption Detection system for Adhoc On-demand Distance Vector (ID-AODV) protocol is presented based on finite state machine. The packet dropping and sequence number attacks are closely investigated and detection systems for both types of attacks are designed. The major functional modules of ID-AODV includes network monitoring system, finite state machine and attack detection model. Simulations are carried out in network simulator NS-2 to evaluate the performance of the proposed framework. A comparative evaluation of the performance is also performed with the state-of-the-art techniques: RIDAN and AODV. The performance evaluations attest the benefits of proposed framework in terms of providing better security for denial of service and intrusion detection attacks.

Anti-Semitism in American Caricature.

ERIC Educational Resources Information Center

Appel, John; Appel, Selma

1986-01-01

Caricatures produced between the end of the Civil War and World War II--cartoons in humor and satire weeklies, newspaper comics, posters, advertising, book illustrations, etc.--sanctioned ethnic and racial slurs. Jews were presented as negative stereotypes, characterized most often by stealth and derision. (LHW)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, Ian M.; Collins, Aaron M.; Quintana, Hope A.

In this study, we develop a quantitative dye dequenching technique for the measurement of polymersome fusion, using it to characterize the salt mediated, mechanically-induced fusion of polymersomes with polymer, lipid, and so-called stealth lipid vesicles. While dye dequenching has been used to quantitatively explore liposome fusion in the past, this is the first use of dye dequenching to measure polymersome fusion of which we are aware. In addition to providing quantitative results, dye dequenching is ideal for detecting fusion in instances where DLS results would be ambiguous, such as low yield levels and size ranges outside the capabilities of DLS.more » The dye chosen for this study was a cyanine derivative, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR), which proved to provide excellent data on the extent of polymersome fusion. Using this technique, we have shown the limited fusion capabilities of polymersome/liposome heterofusion, notably DOPC vesicles fusing with polymersomes at half the efficiency of polymersome homofusion and DPPC vesicles showing virtually no fusion. In addition to these key heterofusion experiments, we determined the broad applicability of dye dequenching in measuring kinetic rates of polymersome fusion; and showed that even at elevated temperatures or over multiple weeks' time, no polymersome fusion occurred without agitation. Stealth liposomes formed from DPPC and PEO-functionalized lipid, however, fused with polymersomes and stealth liposomes with relatively high efficiency, lending support to our hypothesis that the response of the PEO corona to salt is a key factor in the fusion process. This last finding suggests that although the conjugation of PEO to lipids increases vesicle biocompatibility and enables their longer circulation times, it also renders the vesicles subject to destabilization under high salt and shear (e.g. in the circulatory system) that may lead to, in this case, fusion.« less

A lightweight and secure two factor anonymous authentication protocol for Global Mobility Networks.

PubMed

Baig, Ahmed Fraz; Hassan, Khwaja Mansoor Ul; Ghani, Anwar; Chaudhry, Shehzad Ashraf; Khan, Imran; Ashraf, Muhammad Usman

2018-01-01

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.'s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols.

A lightweight and secure two factor anonymous authentication protocol for Global Mobility Networks

PubMed Central

2018-01-01

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.’s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols. PMID:29702675

Mycosphaerella comparative genomics reveals chromosome dynamics, genome evolution and stealth pathogenesis

USDA-ARS?s Scientific Manuscript database

Mycosphaerella graminicola causes septoria tritici blotch, one of the most important diseases of wheat worldwide. Previous analyses showed that populations of this species are extremely variable and that polymorphisms for chromosome length and number can be generated during meiosis. To better unders...

Running bumps from stealth bosons

NASA Astrophysics Data System (ADS)

Aguilar-Saavedra, J. A.

2018-03-01

For the `stealth bosons' S, light boosted particles with a decay S → A A → q \\bar{q} q \\bar{q} into four quarks and reconstructed as a single fat jet, the groomed jet mass has a strong correlation with groomed jet substructure variables. Consequently, the jet mass distribution is strongly affected by the jet substructure selection cuts when applied on the groomed jet. We illustrate this fact by recasting a CMS search for low-mass dijet resonances and show a few representative examples. The mass distributions exhibit narrow and wide bumps at several locations in the 100-300 GeV range, between the masses of the daughter particles A and the parent particle S, depending on the jet substructure selection. This striking observation introduces several caveats when interpreting and comparing experimental results, for the case of non-standard signatures. The possibility that a single boosted particle decaying hadronically produces multiple bumps, at quite different jet masses, and depending on the event selection, brings the anomaly chasing game to the next level.

CNT Nanobombs for Specific Eradication of Cancer Cells: A New Concept in Cancer Theranostics.

PubMed

Omidi, Yadollah

2011-01-01

Whole extermination of cancerous cells/tissue seems no longer to be a dream. Exploiting advanced photoactive nanomaterials such as functionalized fullerenes and carbon nano-tubes (CNTs) can act as CNT nanobombs (CNT-NBs) when exposed to the near infrared (NIR) radiation. PEGylated CNTs tagged with an antibody/aptamer can target cancer cells. Once attached to cancer cells, the NIR emission (700-1100 nm), in which body tissues are mostly transparent, can be applied to CNT-NBs which can absorb the light and get heated up. The resultant enhanced temperature can abolish the cancer. Once stealth CNT-NBs are tagged with imaging moieties, it would be a matter of computer gaming for physician who can inject it for real time visualization and destruction of cancer by activation of the NIR laser. While, many nanosystems (NSs) are still in waiting list for clinical translation, our dreams may come true by applying stealth CNT-NBs against cancer.

[Spectral investigation of atmospheric pressure plasma column].

PubMed

Li, Xue-Chen; Chang, Yuan-Yuan; Xu, Long-Fei

2012-07-01

Atmospheric pressure plasma column has many important applications in plasma stealth for aircraft. In the present paper, a plasma column with a length of 65 cm was generated in argon at atmospheric pressure by using dielectric barrier discharge device with water electrodes in coaxial configurations. The discharge mechanism of the plasma column was studied by optical method and the result indicates that a moving layer of light emission propagates in the upstream region. The propagation velocity of the plasma bullet is about 0.6 x 10(5) m x s(-1) through optical measurement. Spectral intensity ratios as functions of the applied voltage and driving frequency were also investigated by spectroscopic method. The variation in spectral intensity ratio implies a change in the averaged electron energy. Results show that the averaged electron energy increases with the increase in the applied voltage and the driving frequency. These results have significant values for industrial applications of the atmospheric pressure discharge and have extensive application potentials in stealth for military aircraft.

Accurate Analysis of Target Characteristic in Bistatic SAR Images: A Dihedral Corner Reflectors Case.

PubMed

Ao, Dongyang; Li, Yuanhao; Hu, Cheng; Tian, Weiming

2017-12-22

The dihedral corner reflectors are the basic geometric structure of many targets and are the main contributions of radar cross section (RCS) in the synthetic aperture radar (SAR) images. In stealth technologies, the elaborate design of the dihedral corners with different opening angles is a useful approach to reduce the high RCS generated by multiple reflections. As bistatic synthetic aperture sensors have flexible geometric configurations and are sensitive to the dihedral corners with different opening angles, they specially fit for the stealth target detections. In this paper, the scattering characteristic of dihedral corner reflectors is accurately analyzed in bistatic synthetic aperture images. The variation of RCS with the changing opening angle is formulated and the method to design a proper bistatic radar for maximizing the detection capability is provided. Both the results of the theoretical analysis and the experiments show the bistatic SAR could detect the dihedral corners, under a certain bistatic angle which is related to the geometry of target structures.

Spatially and spectrally engineered spin-orbit interaction for achromatic virtual shaping

PubMed Central

Pu, Mingbo; Zhao, Zeyu; Wang, Yanqin; Li, Xiong; Ma, Xiaoliang; Hu, Chenggang; Wang, Changtao; Huang, Cheng; Luo, Xiangang

2015-01-01

The geometries of objects are deterministic in electromagnetic phenomena in all aspects of our world, ranging from imaging with spherical eyes to stealth aircraft with bizarre shapes. Nevertheless, shaping the physical geometry is often undesired owing to other physical constraints such as aero- and hydro-dynamics in the stealth technology. Here we demonstrate that it is possible to change the traditional law of reflection as well as the electromagnetic characters without altering the physical shape, by utilizing the achromatic phase shift stemming from spin-orbit interaction in ultrathin space-variant and spectrally engineered metasurfaces. The proposal is validated by full-wave simulations and experimental characterization in optical wavelengths ranging from 600 nm to 2800 nm and microwave frequencies in 8-16 GHz, with echo reflectance less than 10% in the whole range. The virtual shaping as well as the revised law of reflection may serve as a versatile tool in many realms, including broadband and conformal camouflage and Kinoform holography, to name just a few. PMID:25959663

Accurate Analysis of Target Characteristic in Bistatic SAR Images: A Dihedral Corner Reflectors Case

PubMed Central

Ao, Dongyang; Hu, Cheng; Tian, Weiming

2017-01-01

The dihedral corner reflectors are the basic geometric structure of many targets and are the main contributions of radar cross section (RCS) in the synthetic aperture radar (SAR) images. In stealth technologies, the elaborate design of the dihedral corners with different opening angles is a useful approach to reduce the high RCS generated by multiple reflections. As bistatic synthetic aperture sensors have flexible geometric configurations and are sensitive to the dihedral corners with different opening angles, they specially fit for the stealth target detections. In this paper, the scattering characteristic of dihedral corner reflectors is accurately analyzed in bistatic synthetic aperture images. The variation of RCS with the changing opening angle is formulated and the method to design a proper bistatic radar for maximizing the detection capability is provided. Both the results of the theoretical analysis and the experiments show the bistatic SAR could detect the dihedral corners, under a certain bistatic angle which is related to the geometry of target structures. PMID:29271917

Coating nanoparticles with tunable surfactants facilitates control over the protein corona.

PubMed

Müller, J; Bauer, K N; Prozeller, D; Simon, J; Mailänder, V; Wurm, F R; Winzen, S; Landfester, K

2017-01-01

Nanoparticles with long blood circulation time are a prerequisite for targeted drug delivery. To make the nanoparticles invisible for phagocytizing cells, functional moieties on the particle surface are believed to be necessary to attract specific so-called 'stealth' proteins forming a protein 'corona'. Currently, covalent attachment of those moieties represents the only way to achieve that attraction. However, that approach requires a high synthetic effort and is difficult to control. Therefore, we present the coating of model nanoparticles with biodegradable polymeric surfactants as an alternative method. The thermodynamic parameters of the coating process can be tuned by adjusting the surfactants' block lengths and hydrophilicity. Consequently, the unspecific protein adsorption and aggregation tendency of the particles can be controlled, and stealth proteins inhibiting cell uptake are enriched on their surface. This non-covalent approach could be applied to any particle type and thus facilitates tuning the protein corona and its biological impact. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mint Viruses: Beauty, Stealth and Disease

USDA-ARS?s Scientific Manuscript database

Mint has been cultivated for thousands of years for the unique fragrances produced by its volatile oils. The major areas of production include India, the United States, China, and Brazil. Mint is a vegetatively propagated crop and world-wide sharing of plant material along with repeated clonal propa...

Development of Specialized Advanced Materials Curriculum.

ERIC Educational Resources Information Center

Malmgren, Thomas; And Others

This course is intended to give students a comprehensive experience in current and future manufacturing materials and processes. It familiarizes students with: (1) base of composite materials; (2) composites--a very light, strong material used in spacecraft and stealth aircraft; (3) laminates; (4) advanced materials--especially aluminum alloys;…

Owning the Environment: Stealth Soldier - Research Outline

DTIC Science & Technology

2012-05-01

animals during mating season or beating of the chest by dancers during some tribal rituals of war are the natural displays of deception. Some...Journal of the Acoustical Society of America 1996, 100 (3), 1584–1593. Kirkeby, O.; Nelson, P. A.; Hamada, H. The Stereo Dipole: Binaural

The Cheshire Jet: Harnessing Metamaterials to Achieve an Optical Stealth Capability

DTIC Science & Technology

2010-07-01

Prometheus Books, 2005. Hamilton, Dave. Address. 23rd Annual National Test and Evaluation Conference, Hilton Head Island, SC, 15 March 2007. http...ment 2008: Challenges and Implications for the Future Joint Force. Norfolk, VA: Center for Joint Futures, 25 November 2008. Valentine, Jason , Shuang

From conventional to stealth liposomes: a new frontier in cancer chemotherapy.

PubMed

Cattel, Luigi; Ceruti, Maurizio; Dosio, Franco

2003-01-01

Many attempts have been made to achieve good selectivity to targeted tumor cells by preparing specialized carrier agents that are therapeutically profitable for anticancer therapy. Among these, liposomes are the most studied colloidal particles thus far applied in medicine and in particular in antitumor therapy. Although they were first described in the 1960s, only at the beginning of 1990s did the first therapeutic liposomes appear on the market. The first-generation liposomes (conventional liposomes) comprised a liposome-containing amphotericin B, Ambisome (Nexstar, Boulder, CO, USA), used as an antifungal drug, and Myocet (Elan Pharma Int, Princeton, NJ, USA), a doxorubicin-containing liposome, used in clinical trials to treat metastatic breast cancer. The second-generation liposomes ("pure lipid approach") were long-circulating liposomes, such as Daunoxome, a daunorubicin-containing liposome approved in the US and Europe to treat AIDS-related Kaposi's sarcoma. The third-generation liposomes were surface-modified liposomes with gangliosides or sialic acid, which can evade the immune system responsible for removing liposomes from circulation. The fourth-generation liposomes, pegylated liposomal doxorubicin, were called "stealth liposomes" because of their ability to evade interception by the immune system, in the same way as the stealth bomber was able to evade radar. Actually, the only stealth liposome on the market is Caelyx/Doxil (Schering-Plough, Madison NJ, USA), used to cure AIDS-related Kaposi's sarcoma, resistant ovarian cancer and metastatic breast cancer. Pegylated liposomal doxorubicin is characterized by a very long-circulation half-life, favorable pharmacokinetic behavior and specific accumulation in tumor tissues. These features account for the much lower toxicity shown by Caelyx in comparison to free doxorubicin, in terms of cardiotoxicity, vesicant effects, nausea, vomiting and alopecia. Pegylated liposomal doxorubicin also appeared to be less myelotoxic than doxorubicin. Typical forms of toxicity associated to it are acute infusion reaction, mucositis and palmar plantar erythrodysesthesia, which occur especially at high doses or short dosing intervals. Active and cell targeted liposomes can be obtained by attaching some antigen-directed monoclonal antibodies (Moab or Moab fragments) or small proteins and molecules (folate, epidermal growth factor, transferrin) to the distal end of polyethylene glycol in pegylated liposomal doxorubicin. The most promising therapeutic application of liposomes is as non-viral vector agents in gene therapy, characterized by the use of cationic phospholipids complexed with the negatively charged DNA plasmid. The use of liposome formulations in local-regional anticancer therapy is also discussed. Finally, pegylated liposomal doxorubicin containing radionuclides are used in clinical trials as tumor-imaging agents or in positron emission tomography.

FSM-F: Finite State Machine Based Framework for Denial of Service and Intrusion Detection in MANET

PubMed Central

N. Ahmed, Malik; Abdullah, Abdul Hanan; Kaiwartya, Omprakash

2016-01-01

Due to the continuous advancements in wireless communication in terms of quality of communication and affordability of the technology, the application area of Mobile Adhoc Networks (MANETs) significantly growing particularly in military and disaster management. Considering the sensitivity of the application areas, security in terms of detection of Denial of Service (DoS) and intrusion has become prime concern in research and development in the area. The security systems suggested in the past has state recognition problem where the system is not able to accurately identify the actual state of the network nodes due to the absence of clear definition of states of the nodes. In this context, this paper proposes a framework based on Finite State Machine (FSM) for denial of service and intrusion detection in MANETs. In particular, an Interruption Detection system for Adhoc On-demand Distance Vector (ID-AODV) protocol is presented based on finite state machine. The packet dropping and sequence number attacks are closely investigated and detection systems for both types of attacks are designed. The major functional modules of ID-AODV includes network monitoring system, finite state machine and attack detection model. Simulations are carried out in network simulator NS-2 to evaluate the performance of the proposed framework. A comparative evaluation of the performance is also performed with the state-of-the-art techniques: RIDAN and AODV. The performance evaluations attest the benefits of proposed framework in terms of providing better security for denial of service and intrusion detection attacks. PMID:27285146

Finished genome of the fungal wheat pathogen Mycosphaerella graminicola reveals dispensome structure, chromosome plasticity and stealth pathogenesis

USDA-ARS?s Scientific Manuscript database

A finished genome was obtained for Mycosphaerella graminicola, the fungal cause of septoria tritici blotch and a global threat to wheat production, containing thirteen core and eight dispensable chromosomes. The latter, called collectively the dispensome, were dynamic in field and progeny isolates. ...

The Complexity-Adaptability Paradox: Issues for Combat Aircraft Development

DTIC Science & Technology

2011-02-16

to Darwin in many sources, including being engraved in stone on the floor of the California Academy of Science, it is most widely attributed to...showing laser -guided bombs guiding down elevator shafts. Observers have described this combination of precision and stealth as having a ―revolutionary

A Study of Rootkit Stealth Techniques and Associated Detection Methods

DTIC Science & Technology

2007-03-01

Manual . . . . . . . 20 3.1. Rootkit Technology Picture . . . . . . . . . . . . . . . . . . . . 23 3.2. Temporal ordering of a detoured function ...3.12. Detection Classification 3 . . . . . . . . . . . . . . . . . . . . . 43 3.13. Trampoline Function with Modification . . . . . . . . . . . . . 46...63 x List of Tables Table Page 2.1. Incident Categories (AFI 33-138) . . . . . . . . . . . . . . . . . 12 3.1. Inline Function Hook

The Stealth Curriculum: Manipulating America's History Teachers

ERIC Educational Resources Information Center

Stotsky, Sandra

2004-01-01

The purpose of this report is: (1) To point out the features of a number of manipulative supplemental resources for history and social studies teachers; and (2) to show how similarly manipulative professional development workshops propagate the distorted content and recommended teaching practices of such materials to teachers and their…

Proposed activities to prepare for testing advanced/stealth weapons systems

NASA Astrophysics Data System (ADS)

Bishop, Harold T.

1989-08-01

The B-2 brings new challenges for Electromagnetic Pulse (EMP) Testing. This paper discusses the unique characteristics of the B-2 and develops a time line of activities that need to be completed by the AF Weapons Laboratory before EMP testing of the B-2 begins.

Stealth Learning: Unexpected Learning Opportunities through Games

ERIC Educational Resources Information Center

Sharp, Laura A.

2012-01-01

Educators across the country struggle to create engaging, motivating learning environments for their Net Gen students. These learners expect instant gratification that traditional lectures do not provide. This leaves educators searching for innovative ways to engage students in order to encourage learning. One solution is for educators to use…

Understanding the Behaviors of Stealth Applicants in the College Search Process

ERIC Educational Resources Information Center

Dupaul, Stephanie

2010-01-01

Successful enrollment management uses predictive modeling to achieve specific goals for admission rates, yield rates, and class size. Many of these models rely on evaluating an applicant's interest in the institution through measures of pre-application engagement. Recent increases in the number of applicants who do not visibly interact with…

Army Sustainment. Volume 44, Issue 3. May-June 2012

DTIC Science & Technology

2012-06-01

Slaughter said. “We have to look for ways to buy the most nutritious products, like brown rice or whole-grain pastas . With creativity and production, we...nutrition in a stealth way,” Captain Brooks said. “Maybe adding whole-wheat pasta or whole-grain rice to dishes (in place of) regular white pasta

“Stealth dissemination” of macrophage-tumor cell fusions cultured from blood of patients with pancreatic ductal adenocarcinoma

USDA-ARS?s Scientific Manuscript database

Circulating tumor cells (CTCs) appear to be involved in early dissemination of many cancers, although which characteristics are important in metastatic spread are not clear. Here we describe isolation and characterization of macrophage-tumor cell fusions (MTFs) from the blood of pancreatic ductal a...

Measuring Problem Solving Skills in Plants vs. Zombies 2

ERIC Educational Resources Information Center

Shute, Valerie J.; Moore, Gregory R.; Wang, Lubin

2015-01-01

We are using stealth assessment, embedded in "Plants vs. Zombies 2," to measure middle-school students' problem solving skills. This project started by developing a problem solving competency model based on a thorough review of the literature. Next, we identified relevant in-game indicators that would provide evidence about students'…

A Stealth Drug Recall: Who Protects Consumers and Shareholders?

ERIC Educational Resources Information Center

Monseau, Susanna; Lasher, Nancy

2015-01-01

In September 2010, William Weldon, chief executive officer (CEO) and chairman of Johnson & Johnson (J&J), was called to testify in front of the Committee on Oversight and Government Reform to explain the largest product recall in the 125-year history of the well-known pharmaceutical and consumer products company. This article presents a…

Health by Stealth--Exploring the Sociocultural Dimensions of Salutogenesis for Sport, Health and Physical Education Research

ERIC Educational Resources Information Center

McCuaig, Louise; Quennerstedt, Mikael

2018-01-01

Sport, health and physical education (SHPE) researchers have increasingly embraced the salutogenic model of health devised by Aaron Antonvosky, to re-understand and problematise the relation between movement, physical activity or physical education on one hand, and health on the other. However, contemporary research employing Antonovsky's theories…

Stealth Evangelism and the Public Schools

ERIC Educational Resources Information Center

Boston, Bob

2010-01-01

United Methodist minister David Jenkins was meeting with fellow clergy last year in the small Kansas community of Sharon Springs when one of the pastors made what sounded like a routine request. He noted that the Todd Becker Foundation was coming to town, and the evangelical Christian organization, which purports to warn youngsters about the…

Search for long-lived, weakly interacting particles that decay to displaced hadronic jets in proton-proton collisions at s = 8 TeV with the ATLAS detector

DOE PAGES

Aad, G.; Abbott, B.; Abdallah, J.; ...

2015-07-17

A search for the decay of neutral, weakly interacting, long-lived particles using data collected by the ATLAS detector at the LHC is presented. This analysis uses the full data set recorded in 2012: 20.3 fb –1 of proton-proton collision data at √s = 8 TeV. The search employs techniques for reconstructing decay vertices of long-lived particles decaying to jets in the inner tracking detector and muon spectrometer. Signal events require at least two reconstructed vertices. No significant excess of events over the expected background is found, and limits as a function of proper lifetime are reported for the decay ofmore » the Higgs boson and other scalar bosons to long-lived particles and for Hidden Valley Z' and Stealth SUSY benchmark models. The first search results for displaced decays in Z' and Stealth SUSY models are presented. The upper bounds of the excluded proper lifetimes are the most stringent to date.« less

Stealth configurations in vector-tensor theories of gravity

NASA Astrophysics Data System (ADS)

Chagoya, Javier; Tasinato, Gianmassimo

2018-01-01

Studying the physics of compact objects in modified theories of gravity is important for understanding how future observations can test alternatives to General Relativity. We consider a subset of vector-tensor Galileon theories of gravity characterized by new symmetries, which can prevent the propagation of the vector longitudinal polarization, even in absence of Abelian gauge invariance. We investigate new spherically symmetric and slowly rotating solutions for these systems, including an arbitrary matter Lagrangian. We show that, under certain conditions, there always exist stealth configurations whose geometry coincides with solutions of Einstein gravity coupled with the additional matter. Such solutions have a non-trivial profile for the vector field, characterized by independent integration constants, which extends to asymptotic infinity. We interpret our findings in terms of the symmetries and features of the original vector-tensor action, and on the number of degrees of freedom that it propagates. These results are important to eventually describe gravitationally bound configurations in modified theories of gravity, such as black holes and neutron stars, including realistic matter fields forming or surrounding the object.

Search for supersymmetry in events with photons and low missing transverse energy in pp collisions at s = 7   TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.

Many models of new physics, including versions of supersymmetry (SUSY), predict production of events with low missing transverse energy, electroweak gauge bosons, and many energetic final-state particles. The stealth SUSY model yields this signature while conserving R-parity by means of a new hidden sector in which SUSY is approximately conserved. The results of a general search for new physics, with no requirement on missing transverse energy, in events with two photons and four or more hadronic jets are reported. The study is based on a sample of proton-proton collisions at sqrt(s) = 7 TeV corresponding to 4.96 inverse femtobarns ofmore » integrated luminosity collected with the CMS detector in 2011. Based on good agreement between the data and the standard model expectation, the data are used to determine model-independent cross-section limits and a limit on the squark mass in the framework of stealth SUSY. With this first study of its kind, squark masses less than 1430 GeV are excluded at the 95% confidence level.« less

Protection against hostile algorithms in UNIX software

NASA Astrophysics Data System (ADS)

Radatti, Peter V.

1996-03-01

Protection against hostile algorithms contained in Unix software is a growing concern without easy answers. Traditional methods used against similar attacks in other operating system environments such as MS-DOS or Macintosh are insufficient in the more complex environment provided by Unix. Additionally, Unix provides a special and significant problem in this regard due to its open and heterogeneous nature. These problems are expected to become both more common and pronounced as 32 bit multiprocess network operating systems become popular. Therefore, the problems experienced today are a good indicator of the problems and the solutions that will be experienced in the future, no matter which operating system becomes predominate.

An abstract model of rogue code insertion into radio frequency wireless networks. The effects of computer viruses on the Program Management Office

NASA Astrophysics Data System (ADS)

Feudo, Christopher V.

1994-04-01

This dissertation demonstrates that inadequately protected wireless LANs are more vulnerable to rogue program attack than traditional LANs. Wireless LANs not only run the same risks as traditional LANs, but they also run additional risks associated with an open transmission medium. Intruders can scan radio waves and, given enough time and resources, intercept, analyze, decipher, and reinsert data into the transmission medium. This dissertation describes the development and instantiation of an abstract model of the rogue code insertion process into a DOS-based wireless communications system using radio frequency (RF) atmospheric signal transmission. The model is general enough to be applied to widely used target environments such as UNIX, Macintosh, and DOS operating systems. The methodology and three modules, the prober, activator, and trigger modules, to generate rogue code and insert it into a wireless LAN were developed to illustrate the efficacy of the model. Also incorporated into the model are defense measures against remotely introduced rogue programs and a cost-benefit analysis that determined that such defenses for a specific environment were cost-justified.

Investigation of nano lipid vesicles of methotrexate for anti-rheumatoid activity

PubMed Central

Prabhu, Prabhakara; Shetty, Rakshith; Koland, Marina; Vijayanarayana, K; Vijayalakshmi, KK; Nairy, M Harish; Nisha, GS

2012-01-01

Background The purpose of this study was to formulate and evaluate nano lipid vesicles of methotrexate (MTX) for its anti-rheumatoid activity. Methods In this study the principle of both active as well as passive targeting using MTX-loaded stealth liposomes as per the magic gun approach was followed. Stealth liposomes of MTX were prepared by thin-film hydration method using a PEGylated phospholipid-like DSPE-MPEG 2000. Similarly, conventional liposomes were prepared using phospholipids like DPPC and DSPC. Conventional liposomes were coated with a hydrophilic biocompatible polymer like chitosan. They were investigated for their physical properties and in vitro release profile. Further, in vivo screening of the formulations for their anti-rheumatoid efficacy was carried out in rats. Rheumatoid arthritis was induced in male Wistar-Lewis rats using complete Freund’s adjuvant (1 mg/mL Mycobacterium tuberculosis, heat killed in mineral oil). Results It was found that chitosan coating of the conventional liposomes increased the physical stability of the liposomal suspension as well as its entrapment efficiency. The size of the unsonicated lipid vesicles was found to be in the range of 8–10 μm, and the sonicated lipid vesicles in the range of 210–260 nm, with good polydispersity index. Further, chitosan-coated conventional liposomes and the PEGylated liposomes released the drug for a prolonged period of time, compared to the uncoated conventional liposomes. It was found that there was a significant reduction in edema volume in the rat group administered with the test stealth liposomal formulations and chitosan-coated conventional liposomes (PEGylated and chitosan-coated conventional) compared to that of the control and standard (administered with free MTX) group of rats. PEGylated liposomes showed almost equal efficacy as that of the chitosan-coated conventional liposomes. Conclusion Lipid nano vesicles of MTX can be administered by intravenous route, whereby the drug selectively reaches the target site with reduced toxicity to other organs. PMID:22275833

SU-F-P-42: “To Navigate, Or Not to Navigate: HDR BT in Recurrent Spine Lesions”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voros, L; Cohen, G; Zaider, M

Purpose: We compare the accuracy of HDR catheter placement for paraspinal lesions using O-arm CBCT imaging combined with StealthStation navigation and traditional fluoroscopically guided catheter placement. Methods: CT and MRI scans were acquired pre-treatment to outline the lesions and design treatment plans (pre-plans) to meet dosimetric constrains. The pre-planned catheter trajectories were transferred into the StealthStation Navigation system prior to the surgery. The StealthStation is an infra red (IR) optical navigation system used for guidance of surgical instruments. An intraoperative CBCT scan (O-arm) was acquired with reference IR optical fiducials anchored onto the patient and registered with the preplan imagemore » study to guide surgical instruments in relation to the patients’ anatomy and to place the brachytherapy catheters along the pre-planned trajectories. The final treatment plan was generated based on a 2nd intraoperative CBCT scan reflecting achieved implant geometry. The 2nd CBCT was later registered with the initial CT scan to compare the preplanned dwell positions with actual dwell positions (catheter placements). Similar workflow was used in placement of 8 catheters (1 patient) without navigation, but under fluoroscopy guidance in an interventional radiology suite. Results: A total of 18 catheters (3 patients) were placed using navigation assisted surgery. Average displacement of 0.66 cm (STD=0.37cm) was observed between the pre-plan source positions and actual source positions in the 3 dimensional space. This translates into an average 0.38 cm positioning error in one direction including registration errors, digitization errors, and the surgeons ability to follow the planned trajectory. In comparison, average displacement of non-navigated catheters was 0.50 cm (STD=0.22cm). Conclusion: Spinal lesion HDR brachytherapy planning is a difficult task. Catheter placement has a direct impact on target coverage and dose to critical structures. While limited to a handful of patients, our experience shows navigation and fluoroscopy guided placement yield similar results.« less

Performance evaluation of three on-site adulterant detection devices for urine specimens.

PubMed

Peace, Michelle R; Tarnai, Lisa D

2002-10-01

The performance of three on-site adulterant detection devices that assess the integrity of urine specimens collected for drug-of-abuse testing was evaluated: the Intect 7, MASK Ultra Screen, and Adultacheck 4. Intect 7 simultaneously tests creatinine, nitrite, glutaraldehyde, pH, specific gravity, and the presence of bleach and pyridinium chlorochromate (PCC). Mask Ultra Screen tests creatinine, nitrite, pH, specific gravity, and oxidants, and Adultacheck 4 tests creatinine, nitrite, glutaraldehyde, and pH. Urine specimens were prepared with the Substance Abuse and Mental Health Administration regulated analytes at 50% above the cut-off concentrations. Stealth, Urine Luck, Instant Clean ADD-IT-ive, and KLEAR were added individually to the drug-added urine specimens so that their concentrations reflected the "optimum" usage reported in their package inserts and 25% above and below that optimum. Stealth is reported to be peroxidase; Urine Luck is believed to be PCC; Instant Clean ADD-it-ive reportedly contains glutaraldehyde, and Klear is a nitrite. The following diluents/adulterants were added at 25%, 33%, and 50% of the volume of drug-added urine: distilled water, bleach, ammonia, and vinegar. Of the devices tested, Intect 7 proved to be the most sensitive, and it correctly indicated the presence of adulterant or diluent in all samples tested. In order to do so, all indication pads had to be assessed in concert. Adultacheck 4 specifically assesses four characteristics of urine integrity and is therefore very limited in detecting the use of several popular adulterants that are commercially available. Although it correctly assessed the four characteristics, it did not detect the use of Stealth, Urine Luck, or Instant Clean ADD-it-ive. Mask Ultra Screen can potentially detect a broader range of adulterants than Adultacheck 4. However, in practice, it only detected them at levels well above their optimum usage, making it less efficacious than Intect 7. Clearly, the specific identification of an adulterant is a trade-off for sensitive detection of several adulterants.

Buried Craters In Isidis Planitia, Mars

NASA Astrophysics Data System (ADS)

Seabrook, A. M.; Rothery, D. A.; Wallis, D.; Bridges, J. C.; Wright, I. P.

We have produced a topographic map of Isidis Planitia, which includes the Beagle 2 landing site, using interpolated Mars Orbiter Laser Altimeter (MOLA) data from the Mars Global Surveyor (MGS) spacecraft currently orbiting Mars. MOLA data have a vertical precision of 37.5 cm, a footprint size of 130 m, an along-track shot spacing of 330 m, and an across-track spacing that is variable and may be several kilometres. This has revealed subtle topographic detail within the relatively smooth basin of Isidis Planitia. Analysis of this map shows apparent wrinkle ridges that could be the volcanic basement to the basin and also several circular depressions with diameters of several to tens of kilometres which we interpreted as buried impact craters, comparable to the so-called stealth craters recognised elsewhere in the northern lowlands of Mars[1]. Stealth craters are considered to be impact craters subjected to erosion and/or burial. Some of these features in Isidis have depressions that are on the order of tens metres lower than their rims and are very smooth, and so are often not visible in MGS Mars Orbiter Camera (MOC) or Viking images of the basin. The Isidis stealth craters are not restricted to the Hesperian Vastitas Borealis formations like those detected elsewhere in the northern lowlands by Kreslavsky and Head [1], but are also found in a younger Amazonian smooth plains unit. It is generally believed that Isidis Planitia has undergone one or more episodes of sedi- ment deposition, and so these buried craters most likely lie on an earlier surface, which could be the postulated volcanic basement to the basin. Analysis of the buried craters may give some understanding of the thickness, frequencies and ages of sedimentation episodes within the basin. This information will be important in developing a context in which information from the Beagle 2 lander can be analysed when it arrives on Mars in December 2003. [1] Kreslavsky M. A. and Head J. W. (2001) LPS XXXII

Finished Genome of the Fungal Wheat Pathogen Mycosphaerella graminicola Reveals Dispensome Structure, Chromosome Plasticity, and Stealth Pathogenesis

PubMed Central

Ben M'Barek, Sarrah; Dhillon, Braham; Wittenberg, Alexander H. J.; Crane, Charles F.; Hane, James K.; Foster, Andrew J.; Van der Lee, Theo A. J.; Grimwood, Jane; Aerts, Andrea; Antoniw, John; Bailey, Andy; Bluhm, Burt; Bowler, Judith; Bristow, Jim; van der Burgt, Ate; Canto-Canché, Blondy; Churchill, Alice C. L.; Conde-Ferràez, Laura; Cools, Hans J.; Coutinho, Pedro M.; Csukai, Michael; Dehal, Paramvir; De Wit, Pierre; Donzelli, Bruno; van de Geest, Henri C.; van Ham, Roeland C. H. J.; Hammond-Kosack, Kim E.; Henrissat, Bernard; Kilian, Andrzej; Kobayashi, Adilson K.; Koopmann, Edda; Kourmpetis, Yiannis; Kuzniar, Arnold; Lindquist, Erika; Lombard, Vincent; Maliepaard, Chris; Martins, Natalia; Mehrabi, Rahim; Nap, Jan P. H.; Ponomarenko, Alisa; Rudd, Jason J.; Salamov, Asaf; Schmutz, Jeremy; Schouten, Henk J.; Shapiro, Harris; Stergiopoulos, Ioannis; Torriani, Stefano F. F.; Tu, Hank; de Vries, Ronald P.; Waalwijk, Cees; Ware, Sarah B.; Wiebenga, Ad; Zwiers, Lute-Harm; Oliver, Richard P.

2011-01-01

The plant-pathogenic fungus Mycosphaerella graminicola (asexual stage: Septoria tritici) causes septoria tritici blotch, a disease that greatly reduces the yield and quality of wheat. This disease is economically important in most wheat-growing areas worldwide and threatens global food production. Control of the disease has been hampered by a limited understanding of the genetic and biochemical bases of pathogenicity, including mechanisms of infection and of resistance in the host. Unlike most other plant pathogens, M. graminicola has a long latent period during which it evades host defenses. Although this type of stealth pathogenicity occurs commonly in Mycosphaerella and other Dothideomycetes, the largest class of plant-pathogenic fungi, its genetic basis is not known. To address this problem, the genome of M. graminicola was sequenced completely. The finished genome contains 21 chromosomes, eight of which could be lost with no visible effect on the fungus and thus are dispensable. This eight-chromosome dispensome is dynamic in field and progeny isolates, is different from the core genome in gene and repeat content, and appears to have originated by ancient horizontal transfer from an unknown donor. Synteny plots of the M. graminicola chromosomes versus those of the only other sequenced Dothideomycete, Stagonospora nodorum, revealed conservation of gene content but not order or orientation, suggesting a high rate of intra-chromosomal rearrangement in one or both species. This observed “mesosynteny” is very different from synteny seen between other organisms. A surprising feature of the M. graminicola genome compared to other sequenced plant pathogens was that it contained very few genes for enzymes that break down plant cell walls, which was more similar to endophytes than to pathogens. The stealth pathogenesis of M. graminicola probably involves degradation of proteins rather than carbohydrates to evade host defenses during the biotrophic stage of infection and may have evolved from endophytic ancestors. PMID:21695235

Responsible vendors, intelligent consumers: Silk Road, the online revolution in drug trading.

PubMed

Van Hout, Marie Claire; Bingham, Tim

2014-03-01

Silk Road is located on the Deep Web and provides an anonymous transacting infrastructure for the retail of drugs and pharmaceuticals. Members are attracted to the site due to protection of identity by screen pseudonyms, variety and quality of product listings, selection of vendors based on reviews, reduced personal risks, stealth of product delivery, development of personal connections with vendors in stealth modes and forum activity. The study aimed to explore vendor accounts of Silk Road as retail infrastructure. A single and holistic case study with embedded units approach (Yin, 2003) was chosen to explore the accounts of vendor subunits situated within the Silk Road marketplace. Vendors (n=10) completed an online interview via the direct message facility and via Tor mail. Vendors described themselves as 'intelligent and responsible' consumers of drugs. Decisions to commence vending operations on the site centred on simplicity in setting up vendor accounts, and opportunity to operate within a low risk, high traffic, high mark-up, secure and anonymous Deep Web infrastructure. The embedded online culture of harm reduction ethos appealed to them in terms of the responsible vending and use of personally tested high quality products. The professional approach to running their Silk Road businesses and dedication to providing a quality service was characterised by professional advertising of quality products, professional communication and visibility on forum pages, speedy dispatch of slightly overweight products, competitive pricing, good stealth techniques and efforts to avoid customer disputes. Vendors appeared content with a fairly constant buyer demand and described a relatively competitive market between small and big time market players. Concerns were evident with regard to Bitcoin instability. The greatest threat to Silk Road and other sites operating on the Deep Web is not law enforcement or market dynamics, it is technology itself. Copyright © 2013 Elsevier B.V. All rights reserved.

Detectability of high power aircraft

NASA Astrophysics Data System (ADS)

Dettmar, Klaus Uwe; Kruse, Juergen; Loebert, Gerhard

1992-05-01

In addition to the measures aiming at improving the probability of survival for an aircraft, including aircraft performance, flight profile selection, efficient electronic warfare equipment, and self protection weapons, it is shown that an efficient measure consists of reducing aircraft signature (radar, infrared, acoustic, visual) in connection with the use of signature avionics. The American 'stealth' aircrafts are described as examples.

You Are Your Words: Modeling Students' Vocabulary Knowledge with Natural Language Processing Tools

ERIC Educational Resources Information Center

Allen, Laura K.; McNamara, Danielle S.

2015-01-01

The current study investigates the degree to which the lexical properties of students' essays can inform stealth assessments of their vocabulary knowledge. In particular, we used indices calculated with the natural language processing tool, TAALES, to predict students' performance on a measure of vocabulary knowledge. To this end, two corpora were…

Crash Test Kids: Stealth Learning at Its Best

ERIC Educational Resources Information Center

Marshall, Kirk

2011-01-01

Building a human-powered flying craft can be much more complicated than one would first imagine. There are no "premade" plans available for this type of craft. In addition, the crafts needed to be built with some "style," or in other words, they should represent something other than a flying machine. The concept of launching a…

Defense.gov Special Report: Travels With Hagel

Science.gov Websites

institution in ways that we've never had to." Story Hagel Discusses Transitions at Marine Corps Base Base Defense Secretary Chuck Hagel opened his final domestic trip with a stop at Whiteman Air Force Base, home of the 509th Bomb Wing -- the world's only B-2 Spirit stealth bomber unit, where he told

Naval Surface Warfare Center Carderock Division, Technical Digest

DTIC Science & Technology

2001-12-01

Survivability Systems: An Overview Fred J. Fisch 139 Modeling and Simulation of Weapons Effects on Ships Robert R. Wunderlick 143 Intelligent Networks ...communications capability of forces afloat to support emerging network -centric warfare doc- trines. Stealth, for our next generation of warships...fully-inte- grated, fully- networked electronic countermeasures system, developed in parallel and in close coordination with sister systems. An

Improving Product Performance Through New Equipment Training (NET) Techniques

DTIC Science & Technology

2008-12-01

communication equipment with gloves, acquire targets while wearing helmet and protective eyewear , and stealth movement to contact the enemy and...to be utilized in the literature review. We found that the industry and academic information we retrieved was relevant and transferable to the...chapter summarized industry and academic research relevant to enhancing Marines abilities to better notice and correctly utilize Infantry Combat

An aerial-hawking bat uses stealth echolocation to counter moth hearing.

PubMed

Goerlitz, Holger R; ter Hofstede, Hannah M; Zeale, Matt R K; Jones, Gareth; Holderied, Marc W

2010-09-14

Ears evolved in many nocturnal insects, including some moths, to detect bat echolocation calls and evade capture [1, 2]. Although there is evidence that some bats emit echolocation calls that are inconspicuous to eared moths, it is difficult to determine whether this was an adaptation to moth hearing or originally evolved for a different purpose [2, 3]. Aerial-hawking bats generally emit high-amplitude echolocation calls to maximize detection range [4, 5]. Here we present the first example of an echolocation counterstrategy to overcome prey hearing at the cost of reduced detection distance. We combined comparative bat flight-path tracking and moth neurophysiology with fecal DNA analysis to show that the barbastelle, Barbastella barbastellus, emits calls that are 10 to 100 times lower in amplitude than those of other aerial-hawking bats, remains undetected by moths until close, and captures mainly eared moths. Model calculations demonstrate that only bats emitting such low-amplitude calls hear moth echoes before their calls are conspicuous to moths. This stealth echolocation allows the barbastelle to exploit food resources that are difficult to catch for other aerial-hawking bats emitting calls of greater amplitude. Copyright © 2010 Elsevier Ltd. All rights reserved.

RCS Diversity of Electromagnetic Wave Carrying Orbital Angular Momentum.

PubMed

Zhang, Chao; Chen, Dong; Jiang, Xuefeng

2017-11-13

An electromagnetic (EM) wave with orbital angular momentum (OAM) has a helical wave front, which is different from that of the plane wave. The phase gradient can be found perpendicular to the direction of propagation and proportional to the number of OAM modes. Herein, we study the backscattering property of the EM wave with different OAM modes, i.e., the radar cross section (RCS) of the target is measured and evaluated with different OAM waves. As indicated by the experimental results, different OAM waves have the same RCS fluctuation for the simple target, e.g., a small metal ball as the target. However, for complicated targets, e.g., two transverse-deployed small metal balls, different RCSs can be identified from the same incident angle. This valuable fact helps to obtain RCS diversity, e.g., equal gain or selective combining of different OAM wave scattering. The majority of the targets are complicated targets or expanded targets; the RCS diversity can be utilized to detect a weak target traditionally measured by the plane wave, which is very helpful for anti-stealth radar to detect the traditional stealth target by increasing the RCS with OAM waves.

Re-Educating Jet-Engine-Researchers to Stay Relevant

NASA Astrophysics Data System (ADS)

Gal-Or, Benjamin

2016-06-01

To stay relevantly supported, jet-engine researchers, designers and operators should follow changing uses of small and large jet engines, especially those anticipated to be used by/in the next generation, JET-ENGINE-STEERED ("JES") fleets of jet drones but fewer, JES-Stealth-Fighter/Strike Aircraft. In addition, some diminishing returns from isolated, non-integrating, jet-engine component studies, vs. relevant, supersonic, shock waves control in fluidic-JES-side-effects on compressor stall dynamics within Integrated Propulsion Flight Control ("IPFC"), and/or mechanical JES, constitute key relevant methods that currently move to China, India, South Korea and Japan. The central roles of the jet engine as primary or backup flight controller also constitute key relevant issues, especially under post stall conditions involving induced engine-stress while participating in crash prevention or minimal path-time maneuvers to target. And when proper instructors are absent, self-study of the JES-STVS REVOLUTION is an updating must, where STVS stands for wing-engine-airframe-integrated, embedded stealthy-jet-engine-inlets, restructured engines inside Stealth, Tailless, canard-less, Thrust Vectoring IFPC Systems. Anti-terror and Airliners Super-Flight-Safety are anticipated to overcome US legislation red-tape that obstructs JES-add-on-emergency-kits-use.

Buying time-the immune system determinants of the incubation period to respiratory viruses.

PubMed

Hermesh, Tamar; Moltedo, Bruno; López, Carolina B; Moran, Thomas M

2010-11-01

Respiratory viruses cause disease in humans characterized by an abrupt onset of symptoms. Studies in humans and animal models have shown that symptoms are not immediate and appear days or even weeks after infection. Since the initial symptoms are a manifestation of virus recognition by elements of the innate immune response, early virus replication must go largely undetected. The interval between infection and the emergence of symptoms is called the incubation period and is widely used as a clinical score. While incubation periods have been described for many virus infections the underlying mechanism for this asymptomatic phase has not been comprehensively documented. Here we review studies of the interaction between human pathogenic respiratory RNA viruses and the host with a particular emphasis on the mechanisms used by viruses to inhibit immunity. We discuss the concept of the "stealth phase", defined as the time between infection and the earliest detectable inflammatory response. We propose that the "stealth phase" phenomenon is primarily responsible for the suppression of symptoms during the incubation period and results from viral antagonism that inhibits major pathways of the innate immune system allowing an extended time of unhindered virus replication.

Fast and secure handover of intra-ASN IEEE802.16 network by proposed certificate based pre-authentication

NASA Astrophysics Data System (ADS)

Sridevi, B.; Supriya, T. S.; Rajaram, S.

2013-01-01

The current generation of wireless networks has been designed predominantly to support voice and more recently data traffic. WiMAX is currently one of the hottest technologies in wireless. The main motive of the mobile technologies is to provide seamless cost effective mobility. But this is affected by Authentication cost and handover delay since on each handoff the Mobile Station (MS) has to undergo all steps of authentication. Pre-Authentication is used to reduce the handover delay and increase the speed of the Intra-ASN Handover. Proposed Pre-Authentication method is intended to reduce the authentication delay by getting pre authenticated by central authority called Pre Authentication Authority (PAA). MS requests PAA for Pre Authentication Certificate (PAC) before performing handoff. PAA verifies the identity of MS and provides PAC to MS and also to the neighboring target Base Stations (tBSs). MS having time bound PAC can skip the authentication process when recognized by target BS during handoff. It also prevents the DOS (Denial Of Service) attack and Replay attack. It has no wastage of unnecessary key exchange of the resources. The proposed work is simulated by NS2 model and by MATLAB.

Australia’s Submarine Design Capabilities and Capacities: Challenges and Options for the Future Submarine

DTIC Science & Technology

2011-01-01

stealth features requiring specialised noise and vibra- tion skills and propulsion plants requiring other unique skill sets. Personnel with these...analysis Acoustic, wake , thermal, electromagnetic, and other signature analysis Combat systems and ship control Combat system integration, combat system...to-diagnose flow-induced radiated noise Own-sensor performance degradation Note: Risks can be reduced for given designs using scale models

State Actor Threats in 2025

DTIC Science & Technology

2007-04-01

not target tracking (Richardson, Stealth Warplanes, 175.). 51 David A. Fulghum, "New Radars Peel Veil from Hidden Targets," Aviation Week & Space...without meeting any resistance. The world banana population is currently facing such a crisis; bananas are essentially genetic copies of one another...and currently a virus is spreading worldwide, threatening to make the banana , as we know it, extinct.10 In a similar manner, forcing all the

The Stealth Inequities of School Funding: How State and Local School Finance Systems Perpetuate Inequitable Student Spending

ERIC Educational Resources Information Center

Baker, Bruce D.; Corcoran, Sean P.

2012-01-01

In the education world, the existence of funding inequities has long been a known fact, but the sources of these inequities have not always been obvious. Typically, local property tax variation has been blamed as the sole, or at least primary, cause of inequalities and called for greater state funding as the solution. In practice, however, it is…

Performance Characterization of Polyimide-Carbon Fiber Composites for Future Hypersonic Vehicles

DTIC Science & Technology

2010-08-01

already being processed for leading edge primary structures and engine components for present and future stealth aircraft. In addition to describing our...The form of entry is the last name, first name, middle initial, and additional qualifiers separated by commas, e.g. Smith, Richard, Jr. 7...availability or distribution limitations of the report. If additional limitations/restrictions or special markings are indicated, follow agency

Perspective: The Stealth of Implicit Bias in Chemical Engineering Education, Its Threat to Diversity, and What Professors Can Do to Promote an Inclusive Future

ERIC Educational Resources Information Center

Farrell, Stephanie; Minerick, Adrienne R.

2018-01-01

Many educators hold fairness and egalitarianism as core values that they strive to uphold in their professional work and personal lives, and they hope that they evaluate and support students based strictly on student potential and achievement. However, everyone holds unconscious beliefs about social and identity groups. This implicit (unconscious)…

Papering Over Corrosion

NASA Technical Reports Server (NTRS)

2000-01-01

Kennedy Space Center's battle against corrosion led to a new coating that was licensed to GeoTech and is commercially sold as Catize. The coating uses ligno sulfonic acid doped polyaniline (Ligno-Pani), also known as synthetic metal. Ligno-Pani can be used to extend the operating lives of steel bridges as one example of its applications. future applications include computers, televisions, cellular phones, conductive inks, and stealth technology.

Neuroprotection and Anti-Epileptogenesis with Mitochondria-Targeted Antioxidant

DTIC Science & Technology

2016-06-01

antioxidant, SS-31 in the pilocarpine (PILO) model of status epilepticus (SE), the kindling seizure model and the tetanus toxin (Tx) model of epilepsy...neuroprotective and antiepileptogenic agent in three experimental models of epilepsy. The pilocarpine-induced model of status epilepticus (PILO) was...neuroprotection, seizures, status epilepticus OVERALL PROJECT SUMMARY: SS-31 was created by Dr. Szeto but the rights to the drug are controlled by Stealth

Innovative Strategic Aircraft Design Study (ISADS) Phase 1

DTIC Science & Technology

1978-06-01

will be be applicable to virtually all high-technology aircraft. TECHNICAL APPROACH (U) Required research for the implementation of active controls is...Applicable technologies were assessed In areas of aerodynamics, propulsion, struictures, controls , and stealth, and were found to offer up to SO...15 Nonplanar Wings Variable Camber 17 Laminar Flow 17 Jet Flaps 18 Wing Boundary Layer Control 19 Ground Effect 20 Aeroelastic Tailoring 20 Propulsion

High Strain Rate Material Behavior

DTIC Science & Technology

1985-12-01

data. iii Mr. Dennis Paisely conducted the single plate impact test. Mr. Danny Yaziv is responsible for developing the double flyer plate technique and...neck developed . The sharp rise in the flow stress is due to the increased strain-rates during necking. The maximum observed value of effective stress...for the material modeling. Computer programs and special purpose subroutines were developed to use the Bodner-Partom model in the STEALTH finite

Fighting Networks: The Defining Challenge of Irregular Warfare

DTIC Science & Technology

2011-06-01

Terror on the Internet, describes the collection of this information as “data mining ,” and describes extensive research, information sharing using...suicide bombings. The first, a dramatically increased use of mines and IEDs, reflects both their ability to emplace such explosive devices stealthfully, as...well as the Russian reliance on more static positions supported by road arteries. The ‘ mine warfare’ employed by the Chechen fighters presented

Applications of sub-audible speech recognition based upon electromyographic signals

NASA Technical Reports Server (NTRS)

Jorgensen, C. Charles (Inventor); Betts, Bradley J. (Inventor)

2009-01-01

Method and system for generating electromyographic or sub-audible signals (''SAWPs'') and for transmitting and recognizing the SAWPs that represent the original words and/or phrases. The SAWPs may be generated in an environment that interferes excessively with normal speech or that requires stealth communications, and may be transmitted using encoded, enciphered or otherwise transformed signals that are less subject to signal distortion or degradation in the ambient environment.

Elasticity of bilayers containing PEG lipids

NASA Astrophysics Data System (ADS)

Bivas, I.; Winterhalter, M.; Méléard, P.; Bothorel, P.

1998-02-01

The addition of lipids with a poly(ethylene glycol) head group (Stealth or grafted or PEG lipids) to a phosphatidylcholine bilayer changes the mechanical properties of the membrane. We calculate the dependences of the bending and stretching elasticities of the bilayer on the PEG lipid concentration and on the monomer number in its polymer chain. The role of the bending elasticity at blocked flip-flop of the pure bilayer is revealed.

Fixed-Price Development Contracts: A Historical Perspective

DTIC Science & Technology

2012-09-01

its rival, Boeing, in 1997 ( Boyne , 2002). 36   F-117 Nighthawk In the 1970s, the Air Force expressed a desire to integrate stealth...original cost-reimbursement contract was later changed to a fixed-price incentive contract by Secretary of the Navy John Lehman in response to...inquiry [Memorandum for the Secretary of the Navy]. Washington, DC: Department of the Navy. Boyne , W. (2002). Air warfare: An international

Thermochromic properties of W-doped VO2 thin films deposited by aqueous sol-gel method for adaptive infrared stealth application

NASA Astrophysics Data System (ADS)

Liu, Dongqing; Cheng, Haifeng; Xing, Xin; Zhang, Chaoyang; Zheng, Wenwei

2016-07-01

The W doped VO2 thin films with various W contents were successfully deposited by aqueous sol-gel method followed by a post annealing process. The derived thin films were characterized by X-ray diffraction, Raman spectra, scanning electron microscopy and atomic force microscopy. Besides, the resistance-temperature relationship and infrared emissivity in the waveband 7.5-14 μm were analyzed, and the effects of W doping on the thermochromic properties of VO2 thin films were studied. The results show that W atoms enter the crystal lattice of VO2 and the transition temperature decreases gradually with increasing doping amount of W. The emissivity of VO2-W-4% thin films has dropped to 0.4 when its real temperature is above 30 °C. The thermal infrared images were also examined under different temperature by thermal imager. The results indicate that the temperature under which W doped VO2 thin films begin to have lower emissivity decreases gradually with increasing doping amount of W. W doped VO2 thin films can control its infrared radiation intensity actively at a lower temperature level of 30 °C, which has great application prospects in the adaptive infrared stealth technology.

Monostatic Radar Cross Section Estimation of Missile Shaped Object Using Physical Optics Method

NASA Astrophysics Data System (ADS)

Sasi Bhushana Rao, G.; Nambari, Swathi; Kota, Srikanth; Ranga Rao, K. S.

2017-08-01

Stealth Technology manages many signatures for a target in which most radar systems use radar cross section (RCS) for discriminating targets and classifying them with regard to Stealth. During a war target’s RCS has to be very small to make target invisible to enemy radar. In this study, Radar Cross Section of perfectly conducting objects like cylinder, truncated cone (frustum) and circular flat plate is estimated with respect to parameters like size, frequency and aspect angle. Due to the difficulties in exactly predicting the RCS, approximate methods become the alternative. Majority of approximate methods are valid in optical region and where optical region has its own strengths and weaknesses. Therefore, the analysis given in this study is purely based on far field monostatic RCS measurements in the optical region. Computation is done using Physical Optics (PO) method for determining RCS of simple models. In this study not only the RCS of simple models but also missile shaped and rocket shaped models obtained from the cascaded objects with backscatter has been computed using Matlab simulation. Rectangular plots are obtained for RCS in dbsm versus aspect angle for simple and missile shaped objects using Matlab simulation. Treatment of RCS, in this study is based on Narrow Band.

Modelling of long-wave chaotic radar system for anti-stealth applications

NASA Astrophysics Data System (ADS)

Al-Suhail, Ghaida A.; Tahir, Fadhil Rahma; Abd, Mariam Hussien; Pham, Viet-Thanh; Fortuna, Luigi

2018-04-01

Although the Very Low-Frequency (VLF) waveforms have limited practical applications in acoustics (sonar) and secure military communications with radars and submarines; to this end; this paper presents a new and simple analytical model of VLF monostatic direct chaotic radar system. The model hypothetically depends on the two identical coupled time-delayed feedback chaotic systems which can generate and recover a long-wave chaotic signal. To resist the influence of positive Lyapunov exponents of the time-delay chaotic systems, the complete replacement of Pecaro and Carroll (PC) synchronization is employed. It can faithfully recover the chaotic signal from the back-scattered (echo) signal from the target over a noisy channel. The system performance is characterized in terms of the time series of synchronization in addition to the peak of the cross-correlation. Simulation results are conducted for substantial sensitivities of the chaotic signal to the system parameters and initial conditions. As a result, it is found that an effective and robust chaotic radar (CRADAR) model can be obtained when the signal-to-noise ratio (SNR) highly degrades to 0 dB, but with clear peak in correlation performance for detecting the target. Then, the model can be considered as a state of the art towards counter stealth technology and might be developed for other acoustic secure applications.

Study of plasma-based stable and ultra-wideband electromagnetic wave absorption for stealth application

NASA Astrophysics Data System (ADS)

Xuyang, CHEN; Fangfang, SHEN; Yanming, LIU; Wei, AI; Xiaoping, LI

2018-06-01

A plasma-based stable, ultra-wideband electromagnetic (EM) wave absorber structure is studied in this paper for stealth applications. The stability is maintained by a multi-layer structure with several plasma layers and dielectric layers distributed alternately. The plasma in each plasma layer is designed to be uniform, whereas it has a discrete nonuniform distribution from the overall view of the structure. The nonuniform distribution of the plasma is the key to obtaining ultra-wideband wave absorption. A discrete Epstein distribution model is put forward to constrain the nonuniform electron density of the plasma layers, by which the wave absorption range is extended to the ultra-wideband. Then, the scattering matrix method (SMM) is employed to analyze the electromagnetic reflection and absorption of the absorber structure. In the simulation, the validation of the proposed structure and model in ultra-wideband EM wave absorption is first illustrated by comparing the nonuniform plasma model with the uniform case. Then, the influence of various parameters on the EM wave reflection of the plasma are simulated and analyzed in detail, verifying the EM wave absorption performance of the absorber. The proposed structure and model are expected to be superior in some realistic applications, such as supersonic aircraft.

Optimization of the fabrication of novel stealth PLA-based nanoparticles by dispersion polymerization using D-optimal mixture design

PubMed Central

Adesina, Simeon K.; Wight, Scott A.; Akala, Emmanuel O.

2015-01-01

Purpose Nanoparticle size is important in drug delivery. Clearance of nanoparticles by cells of the reticuloendothelial system has been reported to increase with increase in particle size. Further, nanoparticles should be small enough to avoid lung or spleen filtering effects. Endocytosis and accumulation in tumor tissue by the enhanced permeability and retention effect are also processes that are influenced by particle size. We present the results of studies designed to optimize crosslinked biodegradable stealth polymeric nanoparticles fabricated by dispersion polymerization. Methods Nanoparticles were fabricated using different amounts of macromonomer, initiators, crosslinking agent and stabilizer in a dioxane/DMSO/water solvent system. Confirmation of nanoparticle formation was by scanning electron microscopy (SEM). Particle size was measured by dynamic light scattering (DLS). D-optimal mixture statistical experimental design was used for the experimental runs, followed by model generation (Scheffe polynomial) and optimization with the aid of a computer software. Model verification was done by comparing particle size data of some suggested solutions to the predicted particle sizes. Results and Conclusion Data showed that average particle sizes follow the same trend as predicted by the model. Negative terms in the model corresponding to the crosslinking agent and stabilizer indicate the important factors for minimizing particle size. PMID:24059281

Optimization of the fabrication of novel stealth PLA-based nanoparticles by dispersion polymerization using D-optimal mixture design.

PubMed

Adesina, Simeon K; Wight, Scott A; Akala, Emmanuel O

2014-11-01

Nanoparticle size is important in drug delivery. Clearance of nanoparticles by cells of the reticuloendothelial system has been reported to increase with increase in particle size. Further, nanoparticles should be small enough to avoid lung or spleen filtering effects. Endocytosis and accumulation in tumor tissue by the enhanced permeability and retention effect are also processes that are influenced by particle size. We present the results of studies designed to optimize cross-linked biodegradable stealth polymeric nanoparticles fabricated by dispersion polymerization. Nanoparticles were fabricated using different amounts of macromonomer, initiators, crosslinking agent and stabilizer in a dioxane/DMSO/water solvent system. Confirmation of nanoparticle formation was by scanning electron microscopy (SEM). Particle size was measured by dynamic light scattering (DLS). D-optimal mixture statistical experimental design was used for the experimental runs, followed by model generation (Scheffe polynomial) and optimization with the aid of a computer software. Model verification was done by comparing particle size data of some suggested solutions to the predicted particle sizes. Data showed that average particle sizes follow the same trend as predicted by the model. Negative terms in the model corresponding to the cross-linking agent and stabilizer indicate the important factors for minimizing particle size.

Cancer terminator viruses (CTV): A better solution for viral-based therapy of cancer.

PubMed

Emdad, Luni; Das, Swadesh K; Wang, Xiang-Yang; Sarkar, Devanand; Fisher, Paul B

2018-08-01

In principle, viral gene therapy holds significant potential for the therapy of solid cancers. However, this promise has not been fully realized and systemic administration of viruses has not proven as successful as envisioned in the clinical arena. Our research is focused on developing the next generation of efficacious viruses to specifically treat both primary cancers and a major cause of cancer lethality, metastatic tumors (that have spread from a primary site of origin to other areas in the body and are responsible for an estimated 90% of cancer deaths). We have generated a chimeric tropism-modified type 5 and 3 adenovirus that selectively replicates in cancer cells and simultaneously produces a secreted anti-cancer toxic cytokine, melanoma differentiation associated gene-7/Interleukin-24 (mda-7/IL-24), referred to as a Cancer Terminator Virus (CTV) (Ad.5/3-CTV). In preclinical animal models, injection into a primary tumor causes selective cell death and therapeutic activity is also observed in non-injected distant tumors, that is, "bystander anti-tumor activity." To enhance the impact and therapeutic utility of the CTV, we have pioneered an elegant approach in which viruses are encapsulated in microbubbles allowing "stealth delivery" to tumor cells that when treated with focused ultrasound causes viral release killing tumor cells through viral replication, and producing and secreting MDA-7/IL-24, which stimulates the immune system to attack distant cancers, inhibits tumor angiogenesis and directly promotes apoptosis in distant cancer cells. This strategy is called UTMD (ultrasound-targeted microbubble-destruction). This novel CTV and UTMD approach hold significant promise for the effective therapy of primary and disseminated tumors. © 2017 Wiley Periodicals, Inc.

Mesoporous silica nanoparticles for treating spinal cord injury

NASA Astrophysics Data System (ADS)

White-Schenk, Désirée.; Shi, Riyi; Leary, James F.

2013-02-01

An estimated 12,000 new cases of spinal cord injury (SCI) occur every year in the United States. A small oxidative molecule responsible for secondary injury, acrolein, is an important target in SCI. Acrolein attacks essential proteins and lipids, creating a feed-forward loop of oxidative stress in both the primary injury area and the surrounding areas. A small molecule used and FDA-approved for hypertension, hydralazine, has been found to "scavenge" acrolein after injury, but its delivery and short half-life, as well as its hypertension effects, hinder its application for SCI. Nanomedical systems broaden the range of therapeutic availability and efficacy over conventional medicine. They allow for targeted delivery of therapeutic molecules to tissues of interest, reducing side effects of untargeted therapies in unwanted areas. Nanoparticles made from silica form porous networks that can carry therapeutic molecules throughout the body. To attenuate the acrolein cascade and improve therapeutic availability, we have used a one-step, modified Stober method to synthesize two types of silica nanoparticles. Both particles are "stealth-coated" with poly(ethylene) glycol (PEG) (to minimize interactions with the immune system and to increase circulation time), which is also a therapeutic agent for SCI by facilitating membrane repair. One nanoparticle type contains an amine-terminal PEG (SiNP-mPEG-Am) and the other possesses a terminal hydrazide group (SiNP-mPEG-Hz). The former allows for exploration of hydralazine delivery, loading, and controlled release. The latter group has the ability to react with acrolein, allowing the nanoparticle to scavenge directly. The nanoparticles have been characterized and are being explored using neuronal PC-12 cells in vitro, demonstrating the potential of novel silica nanoparticles for use in attenuating secondary injury after SCI.

When the human viral infectome and diseasome networks collide: towards a systems biology platform for the aetiology of human diseases

PubMed Central

2011-01-01

Background Comprehensive understanding of molecular mechanisms underlying viral infection is a major challenge towards the discovery of new antiviral drugs and susceptibility factors of human diseases. New advances in the field are expected from systems-level modelling and integration of the incessant torrent of high-throughput "-omics" data. Results Here, we describe the Human Infectome protein interaction Network, a novel systems virology model of a virtual virus-infected human cell concerning 110 viruses. This in silico model was applied to comprehensively explore the molecular relationships between viruses and their associated diseases. This was done by merging virus-host and host-host physical protein-protein interactomes with the set of genes essential for viral replication and involved in human genetic diseases. This systems-level approach provides strong evidence that viral proteomes target a wide range of functional and inter-connected modules of proteins as well as highly central and bridging proteins within the human interactome. The high centrality of targeted proteins was correlated to their essentiality for viruses' lifecycle, using functional genomic RNAi data. A stealth-attack of viruses on proteins bridging cellular functions was demonstrated by simulation of cellular network perturbations, a property that could be essential in the molecular aetiology of some human diseases. Networking the Human Infectome and Diseasome unravels the connectivity of viruses to a wide range of diseases and profiled molecular basis of Hepatitis C Virus-induced diseases as well as 38 new candidate genetic predisposition factors involved in type 1 diabetes mellitus. Conclusions The Human Infectome and Diseasome Networks described here provide a unique gateway towards the comprehensive modelling and analysis of the systems level properties associated to viral infection as well as candidate genes potentially involved in the molecular aetiology of human diseases. PMID:21255393

The Prediction of Unsteady Aerodynamic Loading in High Aspect Ratio Wall Bounded Jets

NASA Astrophysics Data System (ADS)

Lurie, Michael B.

Stealth aircraft are becoming more and more prevalent in the aircraft industry. One of the features of many stealth aircraft is an integrated engine that is mounted above the aircraft fuselage. The engine nozzle is often rectangular with a high aspect ratio, and exhausts onto a jet deck formed by the aircraft fuselage. This configuration allows the aircraft fuselage to shield the noise and other detectable features caused by the engine from the ground. The Northrop Grumman B2 Bomber is perhaps the most well-known example of this configuration. Additionally, stealth technology combined with unmanned aerial vehicles (UAV's) has led to the Joint Unmanned Combat System project, or J-UCAS. Both of the aircraft in development in this project use a wall-bounded high aspect ratio nozzle for stealth purposes. While these engine configurations provide a low radar profile and reduce the noise levels on the ground, they do introduce additional considerations. Since the engine is mounted above the aircraft, the nozzle jet is wall bounded by the fuselage of the aircraft. This is known as the flight deck. The jet stream exiting the nozzle can travel at supersonic speeds and potentially generates shock or expansion waves that impinge on the surface of the deck. The oscillations of these shockwaves on the deck produce localized unsteady forces acting on the aircraft. In addition, the interaction between the high speed jet stream and the slower ambient air causes a shear layer to form from the trailing edge of the nozzle. Turbulent eddies form and increase in size as they move downstream. The interactions of the shear layer with the flight deck produce additional unsteady forces on the aircraft. This thesis presents a study to predict the forces on a flight deck caused by a high aspect ratio wall bounded nozzle using both experimental methods and numerical simulations. The experiments performed were conducted on two different nozzles with aspect ratios of 4-1 and 8-1. Several different run conditions, including subsonic, overexpanded, on-design, and under-expanded, are included to study the effects of Mach number on the unsteady pressure. An aluminum flat plate is used to represent the aft deck. The plate is instrumented with Endevco pressure transducers to capture the fluctuating pressure on the aft deck. A spectral analysis performed on the individual sensors shows that the primary sources of fluctuating pressure are the shear layer along with shock-boundary layer interaction. Additional scaling with the nozzle heights is also presented. The numerical simulations were performed using a fully viscous, hybrid RANS/ LES model. They matched the nozzle characteristics and run conditions performed in the experiment. A detailed comparison between the unsteady pressures predicted by the computational simulations and those measured by the experiment is presented. Several discrepancies between the experimental and numerical results are the result of numerical error caused by the time marching scheme used in the simulations. A proper orthogonal decomposition (POD) method is introduced to further analyze the computational simulations and provide a filtering method to obtain more accurate results.

Joint Force Quarterly. Issue 59, 4th Quarter 2010

DTIC Science & Technology

2010-10-01

also be used as part of stealth technology in helicopters to create white noise to cancel or hide the sound of the rotor blades . These magnets are... deficit , the size of the defense budget, and the need to reduce and control costs: DOD Directive 1200.17 recognized that the Reserve Components...Senator Frank Church, inves- tigating intelligence blunders that surfaced in the wake of the Watergate investigation. Now a RAND researcher with many

Brave New Warfare: Autonomy in Lethal UAVs

DTIC Science & Technology

2011-03-01

tremendous support throughout the entirety of my work. I am extremely thankful to my advisors , Dr. George Lucas and CDR William Hatch, USN (ret), for their...that need to be evaluated before unmanned systems assume many roles traditionally held by human personnel. The continual advent of new technology will...2011, the Navy also completed the first test flight of the X-47B, a bat-winged unmanned jet with stealth characteristics.36 The advent of the

Sell, Sell, Sell or Learn, Learn, Learn? The EdTech Market in New Zealand's Education System--Privatisation by Stealth?

ERIC Educational Resources Information Center

Wright, Noeline; Peters, Michael

2017-01-01

An article in "The Atlantic" "Quantifying the Ed-Tech Market" (2015), which draws on a review by the Education Technology Industry Network, reports that the U.S. Ed-tech market totalled $8.38 billion in the 2012-2013 academic year, which is up from $7.9 billion the year before, and up 11.7 per cent from 2009. K-12 online course…

An Assessment of Media Coverage of the B-2 Stealth Bomber

DTIC Science & Technology

1990-01-01

15 Sharon M. Friedman, Carole M. Gorney, and Brenda P. Egolf, "Reporting on Radiation: A Content Analysis of Chernobyl Coverage," Journal of...Mitterrand," Political Science Quarterly, 39 (1987): 103-122. 1 29 Jane Blankenship, Serefa Mendez - Mendez , Jong Guen King and Joseph Giodan, "Initial... Carole M. Gorney and Brenda P. Egolf, "Reporting on Radiation: A Content Analysis of Chernobyl Coverage," Journal of Communication, Summer3 (1987

Integrating SIMNET into Heavy Task Force Tactical Training

DTIC Science & Technology

1994-10-01

the overlays will allow the battlemaster time to input them for display on the Plan View Display ( PVD ) for use in AARs. The time schedule must also...reconnaissance for both friendly and enemy forces to occupy. The stealth station, in conjunction with the Plan View Display ( PVD ), can be used to...was moved to another assembly area for armor crewman and Nuclear, Biological, and Chemical (NBC) skills testing. The battalion observer tested 25% to

Proceedings of the Antenna Applications Symposium (32nd) Held in Monticello, Illinois on 16-18 September 2008. Volume 2

DTIC Science & Technology

2008-12-20

operational concepts. The adaptation or translations of these systems can provide an effective means of addressing many current and emerging challenges . The...providing stealth, cloaking, mimicry and other capabilities such as EM windowing to these platforms presents many challenges as their operational role...physical insight into a complex system or emerging technological challenges . A bio-system that shares synergistic goals with this complex system

AMC’s Future Strategic Airlifter: The Blended Wing Body?

DTIC Science & Technology

2010-06-01

winglets and deflected upwards. Not only does the noise reduction help reduce noise pollution, but it increases the stealth capability of the airlifter...deflected between the large winglets further keeping the waves from extending out from the aircraft to the sides. Based on this observation, Boeing...decided to move the winglets in towards the engines to further shield and deflect sound waves straight above the aircraft as shown in the figures 16

Expansion of Enterprise Requirements and Acquisition Model

DTIC Science & Technology

2012-06-04

upgrades in technology that made it more lethal with a smaller force. Computer technology, GPS, and stealth are just a few examples that allowed...The facility consists of banks of networked computers , large displays all built around a centralized workspace. It can be seen in Figure 3. The...first was to meet a gap in UHF satellite communciations for the Navy. This was satisfied as a Tier-1 program by purchasing additional bandwidth

Intelligent Sensing and Classification in DSR-Based Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Dempsey, Tae; Sahin, Gokhan; Morton, Yu T. (Jade

Wireless ad hoc networks have fundamentally altered today's battlefield, with applications ranging from unmanned air vehicles to randomly deployed sensor networks. Security and vulnerabilities in wireless ad hoc networks have been considered at different layers, and many attack strategies have been proposed, including denial of service (DoS) through the intelligent jamming of the most critical packet types of flows in a network. This paper investigates the effectiveness of intelligent jamming in wireless ad hoc networks using the Dynamic Source Routing (DSR) and TCP protocols and introduces an intelligent classifier to facilitate the jamming of such networks. Assuming encrypted packet headers and contents, our classifier is based solely on the observable characteristics of size, inter-arrival timing, and direction and classifies packets with up to 99.4% accuracy in our experiments.

Passive and Active Analysis in DSR-Based Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Dempsey, Tae; Sahin, Gokhan; Morton, Y. T. (Jade)

Security and vulnerabilities in wireless ad hoc networks have been considered at different layers, and many attack strategies have been proposed, including denial of service (DoS) through the intelligent jamming of the most critical packet types of flows in a network. This paper investigates the effectiveness of intelligent jamming in wireless ad hoc networks using the Dynamic Source Routing (DSR) and TCP protocols and introduces an intelligent classifier to facilitate the jamming of such networks. Assuming encrypted packet headers and contents, our classifier is based solely on the observable characteristics of size, inter-arrival timing, and direction and classifies packets with up to 99.4% accuracy in our experiments. Furthermore, we investigate active analysis, which is the combination of a classifier and intelligent jammer to invoke specific responses from a victim network.

USU AFOSR University Engineering Design Challenge Proposal

DTIC Science & Technology

2015-01-02

gauge, voltmeter, on/off switch Handle ◦ Aluminum, 7.5 in. wide Skirt ◦ EVA foam, abrasion resistant Friction strip ◦ Stealth Rubber 8 12/28/2014 5 Hose...0.962 Tensile Strength [Gpa] 3.2 2.9 1.103 Abrasion Resistance [cycles to failure] 286 83 3.446 Impact Resistance [Energy @ penetration, in-lbs] 125...combination of) terrain to extricate equipment and personnel in situations where the scene is actively on fire or burnt and have exposed sharp metallic

Applied Computational Electromagnetics Society Journal, volume 9, number 1, March 1994

NASA Astrophysics Data System (ADS)

1994-03-01

The partial contents of this document include the following: On the Use of Bivariate Spline Interpolation of Slot Data in the Design of Slotted Waveguide Arrays; A Technique for Determining Non-Integer Eigenvalues for Solutions of Ordinary Differential Equations; Antenna Modeling and Characterization of a VLF Airborne Dual Trailing Wire Antenna System; Electromagnetic Scattering from Two-Dimensional Composite Objects; and Use of a Stealth Boundary with Finite Difference Frequency Domain Simulations of Simple Antenna Problems.

Air Force F-22 Fighter Program: Background and Issues for Congress

DTIC Science & Technology

2009-11-25

recover those critical skills becomes increasingly expensive, particularly where F-22 comprises a large share of their overall business.23 The Air...15, is offering for sale on the international market an upgraded version of the F-15 called the Silent Eagle, which incorporates some added stealth...is only stealthy from the front,” Hirata says, referencing a limitation shared by the Eurofighter Typhoon. “I am afraid that the F-15 Silent Eagle

Net-Warlords: An Information Analysis of the Caballeros Templarios in Mexico

DTIC Science & Technology

2014-12-01

especially marijuana and heroin were smuggled utilizing a simple, effective system consisting of stealth and bribery to move small batches of product into...the United States.21 At this point in the early 1960s, seizure of five pounds of marijuana was considered front page news.22 Today, seizure of drugs...quantities of marijuana became an activity of the past. C. THE PRI AND INSTITUTIONALIZED SMUGGLING: 1964–1975 The decades during and after the

Transformation by stealth: the retargeting of home care services in Finland.

PubMed

Kröger, Teppo; Leinonen, Anu

2012-05-01

This paper analyses the trends and changes that home care services for older people have undergone during the last two decades in Finland. The data used come from national social care statistics, covering the time period from 1990-2010. The results show that, in contrast to many other European nations that have expanded their home care provisions, the coverage levels in Finland have dropped dramatically during this period. Those with the highest needs do receive increased amounts of support, but others have become excluded from publicly funded home care provisions and often need to rely on family members. In most localities, public service provision is focused on personal care, and no longer covers household tasks. This major change of the character of the service is connected to three other recent trends that structure current provisions: the amalgamation of home-based social and healthcare services, the marketisation and emerging privatisation of care and the integration of informal family care into the formal care system. Overall, the changes represent weakening defamilisation, that is, decreasing public responsibility for the needs of many older people and, correspondingly, an increasing reliance on family carers. This full-scale transformation of home care has taken place without any real policy debate or major modification of legislation. No actual decision was ever made to thoroughly alter the character of home care in Finland: the transformation happened by stealth. © 2011 Blackwell Publishing Ltd.

Siderophore vaccine conjugates protect against uropathogenic Escherichia coli urinary tract infection

PubMed Central

Mike, Laura A.; Smith, Sara N.; Sumner, Christopher A.; Eaton, Kathryn A.; Mobley, Harry L. T.

2016-01-01

Uropathogenic Escherichia coli (UPEC) is the primary cause of uncomplicated urinary tract infections (UTIs). Whereas most infections are isolated cases, 1 in 40 women experience recurrent UTIs. The rise in antibiotic resistance has complicated the management of chronic UTIs and necessitates new preventative strategies. Currently, no UTI vaccines are approved for use in the United States, and the development of a highly effective vaccine remains elusive. Here, we have pursued a strategy for eliciting protective immunity by vaccinating with small molecules required for pathogenesis, rather than proteins or peptides. Small iron-chelating molecules called siderophores were selected as antigens to vaccinate against UTI for this vaccine strategy. These pathogen-associated stealth siderophores evade host immune defenses and enhance bacterial virulence. Previous animal studies revealed that vaccination with siderophore receptor proteins protects against UTI. The poor solubility of these integral outer-membrane proteins in aqueous solutions limits their practical utility. Because their cognate siderophores are water soluble, we hypothesized that these bacterial-derived small molecules are prime vaccine candidates. To test this hypothesis, we immunized mice with siderophores conjugated to an immunogenic carrier protein. The siderophore–protein conjugates elicited an adaptive immune response that targeted bacterial stealth siderophores and protected against UTI. Our study has identified additional antigens suitable for a multicomponent UTI vaccine and highlights the potential use of bacterial-derived small molecules as antigens in vaccine therapies. PMID:27821778

The Ghost Is the Machine: How Can We Visibilize the Unseen Norms and Power of Global Health? Comment on "Navigating Between Stealth Advocacy and Unconscious Dogmatism: The Challenge of Researching the Norms, Politics and Power of Global Health".

PubMed

Forman, Lisa

2015-12-03

In his recent commentary, Gorik Ooms argues that "denying that researchers, like all humans, have personal opinions ... drives researchers' personal opinion underground, turning global health science into unconscious dogmatism or stealth advocacy, avoiding the crucial debate about the politics and underlying normative premises of global health." These 'unconscious' dimensions of global health are as Ooms and others suggest, rooted in its unacknowledged normative, political and power aspects. But why would these aspects be either unconscious or unacknowledged? In this commentary, I argue that the 'unconscious' and 'unacknowledged' nature of the norms, politics and power that drive global health is a direct byproduct of the processes through which power operates, and a primary mechanism by which power sustains and reinforces itself. To identify what is unconscious and unacknowledged requires more than broadening the disciplinary base of global health research to those social sciences with deep traditions of thought in the domains of power, politics and norms, albeit that doing so is a fundamental first step. I argue that it also requires individual and institutional commitments to adopt reflexive, humble and above all else, equitable practices within global health research. © 2016 by Kerman University of Medical Sciences.

Robotic autopositioning of the operating microscope.

PubMed

Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

2014-06-01

Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

Siderophore vaccine conjugates protect against uropathogenic Escherichia coli urinary tract infection.

PubMed

Mike, Laura A; Smith, Sara N; Sumner, Christopher A; Eaton, Kathryn A; Mobley, Harry L T

2016-11-22

Uropathogenic Escherichia coli (UPEC) is the primary cause of uncomplicated urinary tract infections (UTIs). Whereas most infections are isolated cases, 1 in 40 women experience recurrent UTIs. The rise in antibiotic resistance has complicated the management of chronic UTIs and necessitates new preventative strategies. Currently, no UTI vaccines are approved for use in the United States, and the development of a highly effective vaccine remains elusive. Here, we have pursued a strategy for eliciting protective immunity by vaccinating with small molecules required for pathogenesis, rather than proteins or peptides. Small iron-chelating molecules called siderophores were selected as antigens to vaccinate against UTI for this vaccine strategy. These pathogen-associated stealth siderophores evade host immune defenses and enhance bacterial virulence. Previous animal studies revealed that vaccination with siderophore receptor proteins protects against UTI. The poor solubility of these integral outer-membrane proteins in aqueous solutions limits their practical utility. Because their cognate siderophores are water soluble, we hypothesized that these bacterial-derived small molecules are prime vaccine candidates. To test this hypothesis, we immunized mice with siderophores conjugated to an immunogenic carrier protein. The siderophore-protein conjugates elicited an adaptive immune response that targeted bacterial stealth siderophores and protected against UTI. Our study has identified additional antigens suitable for a multicomponent UTI vaccine and highlights the potential use of bacterial-derived small molecules as antigens in vaccine therapies.

Using arm and hand gestures to command robots during stealth operations

NASA Astrophysics Data System (ADS)

Stoica, Adrian; Assad, Chris; Wolf, Michael; You, Ki Sung; Pavone, Marco; Huntsberger, Terry; Iwashita, Yumi

2012-06-01

Command of support robots by the warfighter requires intuitive interfaces to quickly communicate high degree-offreedom (DOF) information while leaving the hands unencumbered. Stealth operations rule out voice commands and vision-based gesture interpretation techniques, as they often entail silent operations at night or in other low visibility conditions. Targeted at using bio-signal inputs to set navigation and manipulation goals for the robot (say, simply by pointing), we developed a system based on an electromyography (EMG) "BioSleeve", a high density sensor array for robust, practical signal collection from forearm muscles. The EMG sensor array data is fused with inertial measurement unit (IMU) data. This paper describes the BioSleeve system and presents initial results of decoding robot commands from the EMG and IMU data using a BioSleeve prototype with up to sixteen bipolar surface EMG sensors. The BioSleeve is demonstrated on the recognition of static hand positions (e.g. palm facing front, fingers upwards) and on dynamic gestures (e.g. hand wave). In preliminary experiments, over 90% correct recognition was achieved on five static and nine dynamic gestures. We use the BioSleeve to control a team of five LANdroid robots in individual and group/squad behaviors. We define a gesture composition mechanism that allows the specification of complex robot behaviors with only a small vocabulary of gestures/commands, and we illustrate it with a set of complex orders.

Aural stealth of portable cryogenically cooled infrared imagers

NASA Astrophysics Data System (ADS)

Veprik, Alexander; Vilenchick, Herman; Broyde, Ramon; Pundak, Nachman

2006-05-01

Novel tactics for carrying out military and antiterrorist operations calls for the development of a new generation of portable infrared imagers, the focal plane arrays of which are maintained at a cryogenic temperature. The rotary Stirling cryogenic engines providing for this cooling are usually mounted directly upon the light thin-walled imager frame, which is used for optical alignment, mechanical stability and heat sinking. The known disadvantage of this design approach is that the wideband vibration export produced by the cooler results in structural resonances and therefore in excessive noise radiation from the above imagers. The "noisy" thermal imager may be detected from quite a long distance using acoustic equipment relying upon a high-sensitive unidirectional microphone or aurally spotted when used in a close proximity to the opponent force. As a result, aural stealth along with enhanced imagery, compact design, low power consumption and long life-times become a crucial figure of merit characterising the modern infrared imager. Achieving the desired inaudibility level is a challenging task. As a matter of fact, even the best examples of modern "should-be silent" infrared imagers are quite audible from as far as 50 meters away even when operating in a steady-state mode. The authors report on the successful effort of designing the inaudible at greater then 10 meters cryogenically cooled infrared imager complying with the stringent MIL-STD-1774D (Level II) requirements.

The Effects of Plasma Shield on the Radar Cross Section of a Generic Missile in UHF Band

NASA Astrophysics Data System (ADS)

Chung, Shen

2011-10-01

RF Stealth is the dominant technology in today's military aircraft, and most is achieved by shape design with a few reductions achieved by RAM, but most of these effects are only valid in X band. With the popularity of UHF radar again rising, the possibility of detecting a stealth object has increased due to resonance effect, and this is difficult to decrease with previous means due to the long wavelength. A plasma shield generated in front of an object may be suitable to alter the RCS in specific band without physically changing its shape. We examine the RCS of a generic missile in UHF band, and compared it with one with a cone-shape plasma generated in front of the missile. We find the plasma effectively changes the RCS of the missile, though not necessarily smaller. The RCS of the missile with the plasma shield is now dominated by the plasma instead of the missile. The RCS is a function of the size, shape, and density of the plasma shield. For higher frequency signals like the X band radar, it can still penetrate the plasma, and sees the original RCS of the missile. Due to the relatively lower UHF frequency, the plasma density needed is lower than one in X band and thus more practical to achieve.

Using Arm and Hand Gestures to Command Robots during Stealth Operations

NASA Technical Reports Server (NTRS)

Stoica, Adrian; Assad, Chris; Wolf, Michael; You, Ki Sung; Pavone, Marco; Huntsberger, Terry; Iwashita, Yumi

2012-01-01

Command of support robots by the warfighter requires intuitive interfaces to quickly communicate high degree-of-freedom (DOF) information while leaving the hands unencumbered. Stealth operations rule out voice commands and vision-based gesture interpretation techniques, as they often entail silent operations at night or in other low visibility conditions. Targeted at using bio-signal inputs to set navigation and manipulation goals for the robot (say, simply by pointing), we developed a system based on an electromyography (EMG) "BioSleeve", a high density sensor array for robust, practical signal collection from forearm muscles. The EMG sensor array data is fused with inertial measurement unit (IMU) data. This paper describes the BioSleeve system and presents initial results of decoding robot commands from the EMG and IMU data using a BioSleeve prototype with up to sixteen bipolar surface EMG sensors. The BioSleeve is demonstrated on the recognition of static hand positions (e.g. palm facing front, fingers upwards) and on dynamic gestures (e.g. hand wave). In preliminary experiments, over 90% correct recognition was achieved on five static and nine dynamic gestures. We use the BioSleeve to control a team of five LANdroid robots in individual and group/squad behaviors. We define a gesture composition mechanism that allows the specification of complex robot behaviors with only a small vocabulary of gestures/commands, and we illustrate it with a set of complex orders.

Silent PPOs: the stealth discounting of provider reimbursement.

PubMed

Marks, James W

2005-01-01

Physicians are losing millions of dollars per year from payers engaging in abusive discounting practices. One of the worst of these practices is the silent PPO. This article explains what a silent PPO is and how it unlawfully reduces a provider's reimbursement. The article discusses how providers can recognize silent PPOs and how to protect their practices from this discounting. The article also reviews statutes that prohibit or regulate silent PPOs and recent court decisions finding in favor of providers and against silent PPOs.

Keeping Your Friends Close and Your Enemies Closer: Operational Design for a Nuclear-Armed Iran

DTIC Science & Technology

2006-05-25

using stealth and rapid mobility to achieve their missions.”112 Another definition of “special operation” from Lutwak et al is “self-contained acts of...war mounted by self-sufficient forces operating within hostile territory.” Lutwak et al further state “there is no absolute...kinds.” Moreover, Lutwak et al list six planning principles for successful operations. Among these is “surprise is paramount to all else.” 113

JPRS Report, Near East & South Asia, Kuwait

DTIC Science & Technology

1991-09-13

minutes before the offensive U.S. Air Force F-lI 17A The role the aircraft played in the success of this cam- stealth fighters destroyed a powerful ...to that served as the basis for marking the border, which is be a sham and is characterized by the same method of based on the 1932 Agreement, will be...a passing incident, such as the Council to examine Iraq’s flagrant violation of interna- entry of a military person or a small group of soldiers

CrossTalk: The Journal of Defense Software Engineering. Volume 23, Number 1, Jan/Feb 2010

DTIC Science & Technology

2010-02-01

during implementation have been minimal, but Warren and Abler’s method may change that. by Ron Abler and Ted Warren CMMI, Swiss Cheese , and Pareto...Corbin’s case study of a CMMI appraisal preparation—including Alan Lakein’s “ Swiss Cheese Method” and the Pareto Principle—shows a way other...Stealth CPI: Managing Work Products to Achieve Continuous Process Improvement. Darrell Corbin’s CMMI, Swiss Cheese , and Pareto comes to us from an

Maintenance of Paraoxonase 2 Activity as a Strategy to Attenuate P. Aeruginosa Virulence

DTIC Science & Technology

2013-10-01

identify the putative PON2 interacting protein, our approach is to IP the ~300kD BS3 crosslinked complex with a GFP antibody , run the IP on an SDS-PAGE...Dianova) were used at 1:5000. HRP- conjugated secondary antibodies were from Cell Signaling. Stealth-PON2 and control siRNAs (Invitrogen) sequences and...the lactonase paraoxonase 2 (PON2) and induces many immunomodulatory effects in host cells. Because PON2 rapidly inactivates 3OC12, we hypothesized

Effectiveness of Unmanned Aerial Vehicles in Helping Secure a Border Characterized by Rough Terrain and Active Terrorists

DTIC Science & Technology

2013-06-01

background map is used on top of the battlefield for 26 cosmetic purposes to improve visualization of the scenario. The background map has no effect on...personalities. We assumed that terrorists have a perfect stealth value in enemy contact state and their propensity towards the destination degrades with...Available: http://www.bbc.co.uk/news/world-europe-19615995. [11] “Powerful blast rocks eastern Turkish city, seven reportedly killed ( PHOTOS )” [Online

Distributed Heterogeneous Simulation of a Hybrid-Electric Vehicle

DTIC Science & Technology

2006-03-29

voltage dc bus via a fully controlled three-phase bridge converter. Also connc·:[uJ iu tilL UUS are the Lithium - ion battery bank, the ultra-capacitor...s~b~;~~~~·3 .... ! Lithium - Ion Battery Storage I _ .. ~:; Low-voltage Bus i I I] j i DC~ Converter ! -~~- ti~! 1 I --Ii! Battery i...devices in the propulsion system include the lithium - ion battery bank and the ultra-capacitor. Based on the range of the vehicle in the stealth model

Metal Organic Chemical Vapor Deposition of Oxide Films for Advanced Applications

DTIC Science & Technology

2000-06-01

coatings , photovoltaics, touch sensitive controls, electromagnetic shielding (as found on microwave ovens and stealth fighters), static dissipaters, and so...depositing high quality films. The methods are physical vapor deposition ( PVD ), spin/mist deposition, (CVD), and alternating layer (AL) CVD. PVD ...PZT & SBT, YBa2Cu3O, CeO, InO, TCOs, Varistors Ta2O5 , ZrO, MnO, HfO, CeO, MnO, MgO SAW/microwave Silicon/: Si, SiGe, SiGeC, �. Opto-electronics

Source Selection Simulation: Intact Team Training on Picking a Provider

DTIC Science & Technology

2015-06-01

seat of a new $100 million stealth fighter before giving her flight simulation time. The ar- gument for source-selection simulation ( SSS ) training is...dynamic is the creation of the SSS Tool. Drawing on his success in using a similar tool in contingency contracting, Long decided we should use a Web...of SSS intact team training. On Sept. 30–Oct. 3, 2014, Professors Long and Elsesser de- livered DAU’s first-ever Intact Team SSS Training to Eglin’s

Motivating Non-science Majors: The Technology of Electromagnetic Waves

NASA Astrophysics Data System (ADS)

Henrich, Victor E.

2018-01-01

To address the need for physics courses that stimulate non-STEM majors' interest in, and appreciation of, science, the Department of Applied Physics has developed a popular course for Yale College undergraduates, The Technological World, that explains the physics behind technologies that students use every day. The course provides an in-depth development of electromagnetic waves, applying them to technologies as diverse as LCD displays, GPS, fiber optics, CAT scans, LEDs, and stealth aircraft. It utilizes a conventional lecture format, with many in-class demonstrations.

Computational strategy for the solution of large strain nonlinear problems using the Wilkins explicit finite-difference approach

NASA Technical Reports Server (NTRS)

Hofmann, R.

1980-01-01

The STEALTH code system, which solves large strain, nonlinear continuum mechanics problems, was rigorously structured in both overall design and programming standards. The design is based on the theoretical elements of analysis while the programming standards attempt to establish a parallelism between physical theory, programming structure, and documentation. These features have made it easy to maintain, modify, and transport the codes. It has also guaranteed users a high level of quality control and quality assurance.

Effects of Prior Aging at 288 deg C in Argon Environment on Creep Response of Carbon Fiber Reinforced PMR-15 Composite with + or - 45 deg Fiber Orientation at 288 deg C

DTIC Science & Technology

2009-06-01

typically consists of a thermoset or thermoplastic polymer matrix reinforced with fibers that are much stronger and stiffer than the matrix. The PMCs are...high thermal or electrical conductivity, stealth characteristics , the ability to self-heal, communication, and sensor capabilities. The multi...have factual evidence of limitations and characteristics so as to utilize the material in a manner consistent with its strengths and weaknesses

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

NASA Technical Reports Server (NTRS)

Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellut, Paolo; Sherwin, Gary

2011-01-01

TIR cameras can be used for day/night Unmanned Ground Vehicle (UGV) autonomous navigation when stealth is required. The quality of uncooled TIR cameras has significantly improved over the last decade, making them a viable option at low speed Limiting factors for stereo ranging with uncooled LWIR cameras are image blur and low texture scenes TIR perception capabilities JPL has explored includes: (1) single and dual band TIR terrain classification (2) obstacle detection (pedestrian, vehicle, tree trunks, ditches, and water) (3) perception thru obscurants

Power Requirements for Bi-Harmonic Amplitude and Bias Modulation Control of a Flapping Wing Micro Air Vehicle

DTIC Science & Technology

2013-03-01

acquisition DC Direct current DHPC Discrete harmonic plant compensation DLMs Dorsal longitudinal muscles DOE Design of experiments DOF Degrees of...nature, would have the inherent benefit of stealth through mimicry of insects. Such a MAV is referred to as a flapping wing micro air vehicle (FWMAV...and discrete harmonic plant compensation (DHPC) to manipulate the wings of the FWMAV. A clear understanding of what research has been done in all of

2016 SPD: Day 2

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-06-01

Editors note:This week were in Boulder, Colorado at the 47th meeting of the AAS Solar Physics Division (SPD). Follow along to catch some of the latest news from the field of solar physics!Todays press conference provided an excellent overview of some of the highlights of this weeks SPD meeting. Four speakers provided their views on some of the hottest topics in solar physics at the moment, including stealth coronal mass ejections (CMEs), sunspot formation, long-term solar-activity trends, and the largest solar telescope ever built.Stealth CMEsSolar and Heliospheric Observatory (SOHO) composite image of a coronal mass ejection. [ESA/NASA/SOHO]First up, Nathalia Alzate (Aberystwyth University) talked about recent success in solving the mystery of so-called stealth CMEs, massive solar storms that dont exhibit the usual clues to their origin. Most CMEs have low-coronal signatures like flares, filament eruptions, jets, etc. that reveal the origin of the CME at the Sun. But stealth CMEs appear without warning, and seem to have no evidence of low-coronal signatures.But are these signatures not there? Or could we just be missing them? Alzate and her collaborator Huw Morgan used advanced image processing techniques to search for low-coronal signatures associated with 40 CMEs that have been classified as stealth CMEs. Their techniques enhance the observed structure down to fine spatial scales, and help reveal very faint dynamic events.Sure enough, these processing techniques consistently revealed low-coronal signatures for every single supposed stealth CME they examined. This suggests that all CMEs exhibit some signatures in the low corona its only a matter of being able to process the images well enough to detect them!Spectacular Sunspot SimulationsStill image from a simulation studying sunspot formation. Compare to the cover image of sunspot observations! [Feng Chen, Matthias Rempel, Yuhong Fan]Next up, Feng Chen (High Altitude Observatory) described recent computational advances in simulating sunspot formation. He and his collaborators have used high-performance computing to build a model that successfully reproduces many of the key properties of sunspots that are observed.In particular, these simulations track the motions of the magnetic field starting within the interior of the Sun (8000 km below the surface!). The magnetic field is generated and intensified by convection deep within the solar interior. Bundles of magnetic field then rise through the convection zone, eventually breaking through the solar surface and giving rise to sunspots.This process of tracking the flow as it travels from the convective layer all the way through the solar surface has resulted in what may be some of the highest fidelity simulations of sunspots thus far. The structures produced in these simulations compares very favorably with actual observations of sunspots including the asymmetry seen in most sunspots.Counting Spots on the SunContinuing the discussion of sunspots, Leif Svalgaard (Stanford University) next took us on a historical journey from the 1600s through the present. For the last 400 years starting with Galileo people have kept records of the number of sunspots visible on the Suns disk.One of Galileos drawings of his sunspot observations from 1612. [The Galileo Project]This turns out to be a very useful practice! Total solar irradiance, a measure used as input into climate models, is reconstructed from sunspot numbers. Therefore, the historical record of sunspots over the last 400 years impacts our estimates of the long-term trends in solar activity.Based on raw sunspot counts, studies have argued that solar activity has been steadily increasing over time. But could this be a misinterpretation resulting from the fact that our technology and therefore our ability to detect sunspots has improved over time? Svalgaard believes so.By studying and reconstructing 18th century telescopes, he demonstrates that modern-day sunspot counts are able to detect three times as many sunspots as would have been possible with historical technology. When you normalize for this effect, the data shows that there has therefore not been a steady increase long-term in sunspot numbers.Worlds Largest Solar TelescopeThe final speaker of the press conference was Joe McMullen (National Solar Observatory), who updated us on the status of the Daniel K. Inouye Solar Telescope (DKIST). This 4-meter telescope will be the worlds largest solar telescope, and the first new solar facility that the US has had in several decades.The state of the DKIST telescope site as of July 2015. [NSO/AURA/NSF/Brett Simison]The technology involved in this spectacular telescope is impressive. Its thin, enormous mirror is polished to within an error of nearly 1/10,000th of a human hair! Underlying the telescope is the most complex solar adaptive optics systems ever created, with 1600 different actuators controlling the system real-time to within an error of 4 nanometers. In addition, the entire facility is designed to deal with a tremendous heat load (which can severely limit the quality of observations).DKISTs construction on Haleakala in Hawaii has been underway since 2012, and is making solid progress. The majority of the structures have now been completed, as have most of the major telescope subsystems. The primary hurdle that remains is to integrate all the of components and make sure that they can perform together no small feat!DKIST is expected to begin science operations in 2020, with ~10-20 TB of data being produced each day. This data will be freely and immediately accessible to both researchers and the public.

Performance and non-destructive evaluation methods of airborne radome and stealth structures

NASA Astrophysics Data System (ADS)

Panwar, Ravi; Ryul Lee, Jung

2018-06-01

In the past few years, great effort has been devoted to the fabrication of highly efficient, broadband radome and stealth (R&S) structures for distinct control, guidance, surveillance and communication applications for airborne platforms. The evaluation of non-planar aircraft R&S structures in terms of their electromagnetic performance and structural damage is still a very challenging task. In this article, distinct measurement techniques are discussed for the electromagnetic performance and non-destructive evaluation (NDE) of R&S structures. This paper deals with an overview of the transmission line method and free space measurement based microwave measurement techniques for the electromagnetic performance evaluation of R&S structures. In addition, various conventional as well as advanced methods, such as millimetre and terahertz wave based imaging techniques with great potential for NDE of load bearing R&S structures, are also discussed in detail. A glimpse of in situ NDE techniques with corresponding experimental setup for R&S structures is also presented. The basic concepts, measurement ranges and their instrumentation, measurement method of different R&S structures and some miscellaneous topics are discussed in detail. Some of the challenges and issues pertaining to the measurement of curved R&S structures are also presented. This study also lists various mathematical models and analytical techniques for the electromagnetic performance evaluation and NDE of R&S structures. The research directions described in this study may be of interest to the scientific community in the aerospace sectors.

Development of PEG-PLGA based Intravenous Low Molecular Weight Heparin (LMWH) Nanoparticles Intended to Treat Venous Thrombosis.

PubMed

Jogala, Satheesh; Rachamalla, Shyam Sunder; Aukunuru, Jithan

2016-01-01

Anticoagulant therapy is effective in the treatment of DVT. In this regard, LMWH demonstrated significant promise. It is widely used clinically. The goal of this study was to prepare and evaluate intravenous sustained release stealth nanoparticles encapsulating LMWH using PLGA (polylactidecoglycolide) and different grades of PEG (poly ethylene glycols). The nanoparticles were prepared using w/o/w solvent evaporation technique. Prepared nanoparticles were evaluated for particle size, encapsulation efficiency, in-vitro drug release, anti-thrombotic activity in venous thrombosis rat model, estimation of aPTT, tissue bio-distribution studies and stability. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) studies confirmed the formation of smooth spherical particles. FTIR study reveals successful coating of PEG on the nanoparticles. DSC and XRD results demonstrated that drug changed its physical form in the formulation. The encapsulation efficiency was 63-74%. In vitro drug release was 57-75% for 48 hrs. Macrophage uptake of LMWH with pegylated nanoparticles was less compared to conventional PLGA nanoparticles. In vivo drug release was sustained for 48hrs; Optimized formulation exhibited good enhancement in pharmacokinetic parameters when compared to free drug solution. In vivo sustained release was also demonstrated with antithrombotic activity as well aPTT activity. Optimized formulation demonstrated significant stability, excellent antithrombotic activity in venous thrombosis rat model, improved aPTT levels when compared to free drug solution. An effective stealth LMWH nanoparticle formulation to treat venous thrombosis was successfully developed using w/o/w solvent evaporation technique.

Image guided drug release from pH-sensitive Ion channel-functionalized stealth liposomes into an in vivo glioblastoma model.

PubMed

Pacheco-Torres, Jesus; Mukherjee, Nobina; Walko, Martin; López-Larrubia, Pilar; Ballesteros, Paloma; Cerdan, Sebastian; Kocer, Armagan

2015-08-01

Liposomal drug delivery vehicles are promising nanomedicine tools for bringing cytotoxic drugs to cancerous tissues selectively. However, the triggered cargo release from liposomes in response to a target-specific stimulus has remained elusive. We report on functionalizing stealth-liposomes with an engineered ion channel and using these liposomes in vivo for releasing an imaging agent into a cerebral glioma rodent model. If the ambient pH drops below a threshold value, the channel generates temporary pores on the liposomes, thus allowing leakage of the intraluminal medicines. By using magnetic resonance spectroscopy and imaging, we show that engineered liposomes can detect the mildly acidic pH of the tumor microenvironment with 0.2 pH unit precision and they release their content into C6 glioma tumors selectively, in vivo. A drug delivery system with this level of sensitivity and selectivity to environmental stimuli may well serve as an optimal tool for environmentally-triggered and image-guided drug release. Cancer remains a leading cause of mortality worldwide. With advances in science, delivery systems of anti-cancer drugs have also become sophisticated. In this article, the authors designed and characterized functionalized liposomal vehicles, which would release the drug payload in a highly sensitive manner in response to a change in pH environment in an animal glioma model. The novel data would enable better future designs of drug delivery systems. Copyright © 2015 Elsevier Inc. All rights reserved.

Liposomes Containing Gadodiamide: Preparation, Physicochemical Characterization, and In Vitro Cytotoxic Evaluation.

PubMed

Maia, Ana Luiza Chaves; Fernandes, Christian; de Oliveira, Cynthia Nara Pereira; Teixeira, Claudia Salviano; Oliveira, Mariana Silva; Soares, Daniel Cristian Ferreira; Ramaldes, Gilson Andrade

2017-01-01

The aim of this study was to develop, characterize and assess the cytotoxic activity of pHsensitive (pHL-Gd), stealth pH-sensitive (SpHL-Gd), and conventional (convL-Gd) liposomes containing gadodiamide (Gd-DTPA-BMA). Formulations were prepared by reverse-phase evaporation method and their physicochemical properties were evaluated by means of particle size, zeta potential, and Gd-DTPA-BMA entrapment. SpHL-Gd was considered being the most promising liposome, since it combines stealth and fusogenic characteristics that might contribute to achieve higher therapeutic efficiency. Their drug encapsulation percentages have been optimized satisfactorily. The addition of Gd-DTPA-BMA at 125 μmol/mL in the SpHL-Gd preparation allowed obtaining liposomes with appropriate encapsulation percentage (20.3 ± 0.1%) and entrapment (25.4 ± 0.1 μmol/mL). The cytotoxic studies on the 4T1 breast cancer cell line demonstrated that liposomes-loaded with Gd-DTPA-BMA inhibited cancer cell. pHL-Gd and SpHL-Gd liposomes showed higher activity than convL-Gd and free Gd-DTPA-BMA, indicating that the pH-sensitive characteristic was important to improve intracellular delivery. The presence of polyethylene glycol (PEG) in the SpHL-Gd formulation did not affect the pH-sensitivity and internalization. Therefore, the results of this study suggest the feasibility of liposomes containing Gd-DTPA-BMA as a new promising controlled delivery system. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Engineering Chimeric Receptors To Investigate the Size- and Rigidity-Dependent Interaction of PEGylated Nanoparticles with Cells.

PubMed

Huang, Wei-Chiao; Burnouf, Pierre-Alain; Su, Yu-Cheng; Chen, Bing-Mae; Chuang, Kuo-Hsiang; Lee, Chia-Wei; Wei, Pei-Kuen; Cheng, Tian-Lu; Roffler, Steve R

2016-01-26

Attachment of ligands to the surface of nanoparticles (NPs) is an attractive approach to target specific cells and increase intracellular delivery of nanocargos. To expedite investigation of targeted NPs, we engineered human cancer cells to express chimeric receptors that bind polyethylene glycol (PEG) and internalize stealth NPs in a fashion similar to ligand-targeted liposomes against epidermal growth factor receptor 1 or 2 (HER1 or HER2), which are validated targets for cancer therapy. Measurement of the rate of endocytosis and lysosomal accumulation of small (80-94 nm) or large (180-220 nm) flexible liposomes or more rigid lipid-coated mesoporous silica particles in human HT29 colon cancer and SKBR3 breast cancer cells that express chimeric receptors revealed that larger and more rigid NPs were internalized more slowly than smaller and more flexible NPs. An exception is when both the small and large liposomes underwent endocytosis via HER2. HER1 mediated faster and greater uptake of NPs into cells but retained NPs less well as compared to HER2. Lysosomal accumulation of NPs internalized via HER1 was unaffected by NP rigidity but was inversely related to NP size, whereas large rigid NPs internalized by HER2 displayed increased lysosomal accumulation. Our results provide insight into the effects of NP properties on receptor-mediated endocytosis and suggest that anti-PEG chimeric receptors may help accelerate investigation of targeted stealth NPs.

Navigation accuracy comparing non-covered frame and use of plastic sterile drapes to cover the reference frame in 3D acquisition.

PubMed

Corenman, Donald S; Strauch, Eric L; Dornan, Grant J; Otterstrom, Eric; Zalepa King, Lisa

2017-09-01

Advancements in surgical navigation technology coupled with 3-dimensional (3D) radiographic data have significantly enhanced the accuracy and efficiency of spinal fusion implant placement. Increased usage of such technology has led to rising concerns regarding maintenance of the sterile field, as makeshift drape systems are fraught with breaches thus presenting increased risk of surgical site infections (SSIs). A clinical need exists for a sterile draping solution with these techniques. Our objective was to quantify expected accuracy error associated with 2MM and 4MM thickness Sterile-Z Patient Drape ® using Medtronic O-Arm ® Surgical Imaging with StealthStation ® S7 ® Navigation System. Camera distance to reference frame was investigated for contribution to accuracy error. A testing jig was placed on the radiolucent table and the Medtronic passive reference frame was attached to jig. The StealthStation ® S7 ® navigation camera was placed at various distances from testing jig and the geometry error of reference frame was captured for three different drape configurations: no drape, 2MM drape and 4MM drape. The O-Arm ® gantry location and StealthStation ® S7 ® camera position was maintained and seven 3D acquisitions for each of drape configurations were measured. Data was analyzed by a two-factor analysis of variance (ANOVA) and Bonferroni comparisons were used to assess the independent effects of camera angle and drape on accuracy error. Median (and maximum) measurement accuracy error was higher for the 2MM than for the 4MM drape for each camera distance. The most extreme error observed (4.6 mm) occurred when using the 2MM and the 'far' camera distance. The 4MM drape was found to induce an accuracy error of 0.11 mm (95% confidence interval, 0.06-0.15; P<0.001) relative to the no drape testing, regardless of camera distance. Medium camera distance produced lower accuracy error than either the close (additional 0.08 mm error; 95% CI, 0-0.15; P=0.035) or far (additional 0.21mm error; 95% CI, 0.13-0.28; P<0.001) camera distances, regardless of whether a drape was used. In comparison to the 'no drape' condition, the accuracy error of 0.11 mm when using a 4MM film drape is minimal and clinically insignificant.

Dynamic malware analysis using IntroVirt: a modified hypervisor-based system

NASA Astrophysics Data System (ADS)

White, Joshua S.; Pape, Stephen R.; Meily, Adam T.; Gloo, Richard M.

2013-05-01

In this paper, we present a system for Dynamic Malware Analysis which incorporates the use of IntroVirt™. IntroVirt is an introspective hypervisor architecture and infrastructure that supports advanced analysis techniques for stealth-malwareanalysis. This system allows for complete guest monitoring and interaction, including the manipulation and blocking of system calls. IntroVirt is capable of bypassing virtual machine detection capabilities of even the most sophisticated malware, by spoofing returns to system call responses. Additional fuzzing capabilities can be employed to detect both malware vulnerabilities and polymorphism.

Digital Array Radar for Ballistic Missile Defense and Counter-Stealth Systems Analysis and Parameter Tradeoff Study

DTIC Science & Technology

2006-09-14

specified time. In general the combined vector traces an ellipse when observed in the x-y plane , as illustrated in the following figure.82 176...STANDARD Missile 3 (SM-3) launched from Aegis ships. Depth of fire with SM-3 is limited during an engagement from one 10 platform– generally one, max...will be the technical requirements for the system so that it will be capable of achieving the KPPs specified in the CDD2. Equation 3.1 is the radar

Scheduling Randomly-Deployed Heterogeneous Video Sensor Nodes for Reduced Intrusion Detection Time

NASA Astrophysics Data System (ADS)

Pham, Congduc

This paper proposes to use video sensor nodes to provide an efficient intrusion detection system. We use a scheduling mechanism that takes into account the criticality of the surveillance application and present a performance study of various cover set construction strategies that take into account cameras with heterogeneous angle of view and those with very small angle of view. We show by simulation how a dynamic criticality management scheme can provide fast event detection for mission-critical surveillance applications by increasing the network lifetime and providing low stealth time of intrusions.

The Skies Will Be Falling: Future Technologies and Techniques for the Disruption and Diminishment of Self-Sustainment Cycles in Tropical Cyclonic Systems

DTIC Science & Technology

2009-04-01

to try. Future generations may not forgive us if we dont . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18...believed would be at the level of the Internet, stealth, and UAVs in the next twenty years. He laughed saying that if he knew that he’d get out of...the Air Force and get into the stock market. After the laughter dissipated, he stated that weather was still one of the greatest obstacles to

Review of Relocation of the System Program Office and Logistics Support for the F-117A Stealth Fighter

DTIC Science & Technology

1998-04-10

LMSW. Cost of Repair Number Avoided Nomenclature New Part Cost Repaired Cost Wing platypus panel $60,100 $4,500 10 $ 556,000 Lower rear door panel...72,200 7,000 48 3,129,600 Rear door trailing 76,000 6,000 2 140,000 edge panel Inboard platypus panel 56,000 4,200 46 2,410,400 Outboard platypus panel...Composites Shop’s contribution to resolving the problem consisted of the redesign of the wing and inboard and outboard platypus panels. The Advanced

The science, technology, and politics of ballistic missile defense

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coyle, Philip E.

America's missile defense systems are deployed at home and abroad. This includes the Groundbased Missile Defense (GMD) system in Alaska and California, the Phased Adaptive Approach in Europe (EPAA), and regional systems in the Middle East and Asia. Unfortunately these systems lack workable architectures, and many of the required elements either don't work or are missing. Major review and reconsideration is needed of all elements of these systems. GMD performance in tests has gotten worse with time, when it ought to be getting better. A lack of political support is not to blame as the DoD spends about $10 billionmore » per year, and proposes to add about $5 billion over the next five years. Russia objects to the EPAA as a threat to its ICBM forces, and to the extensive deployment of U.S. military forces in countries such as Poland, the Czech Republic and Romania, once part of the Soviet Union. Going forward the U.S. should keep working with Russia whose cooperation will be key to diplomatic gains in the Middle East and elsewhere. Meanwhile, America's missile defenses face an enduring set of issues, especially target discrimination in the face of attacks designed to overwhelm the defenses, stage separation debris, chaff, decoys, and stealth. Dealing with target discrimination while also replacing, upgrading, or adding to the many elements of U.S. missiles defenses presents daunting budget priorities. A new look at the threat is warranted, and whether the U.S. needs to consider every nation that possesses even short-range missiles a threat to America. The proliferation of missiles of all sizes around the world is a growing problem, but expecting U.S. missile defenses to deal with all those missiles everywhere is unrealistic, and U.S. missile defenses, effective or not, are justifying more and more offensive missiles.« less

The science, technology, and politics of ballistic missile defense

NASA Astrophysics Data System (ADS)

Coyle, Philip E.

2014-05-01

America's missile defense systems are deployed at home and abroad. This includes the Groundbased Missile Defense (GMD) system in Alaska and California, the Phased Adaptive Approach in Europe (EPAA), and regional systems in the Middle East and Asia. Unfortunately these systems lack workable architectures, and many of the required elements either don't work or are missing. Major review and reconsideration is needed of all elements of these systems. GMD performance in tests has gotten worse with time, when it ought to be getting better. A lack of political support is not to blame as the DoD spends about 10 billion per year, and proposes to add about 5 billion over the next five years. Russia objects to the EPAA as a threat to its ICBM forces, and to the extensive deployment of U.S. military forces in countries such as Poland, the Czech Republic and Romania, once part of the Soviet Union. Going forward the U.S. should keep working with Russia whose cooperation will be key to diplomatic gains in the Middle East and elsewhere. Meanwhile, America's missile defenses face an enduring set of issues, especially target discrimination in the face of attacks designed to overwhelm the defenses, stage separation debris, chaff, decoys, and stealth. Dealing with target discrimination while also replacing, upgrading, or adding to the many elements of U.S. missiles defenses presents daunting budget priorities. A new look at the threat is warranted, and whether the U.S. needs to consider every nation that possesses even short-range missiles a threat to America. The proliferation of missiles of all sizes around the world is a growing problem, but expecting U.S. missile defenses to deal with all those missiles everywhere is unrealistic, and U.S. missile defenses, effective or not, are justifying more and more offensive missiles.

Multi-branched ionic liquid-chitosan as a smart and biocompatible nano-vehicle for combination chemotherapy with stealth and targeted properties.

PubMed

Rahimi, Mahdi; Shafiei-Irannejad, Vahid; D Safa, Kazem; Salehi, Roya

2018-09-15

A possible approach for clinical cancer treatment is combination chemotherapy. To address this issue, many anticancer agents have been used simultaneously to achieve synergistic effects with the different mechanism of actions, however, their toxic side effects are still a big challenge. In this study, a smart, biocompatible, magnetic nanocarrier composed of multi-branched ionic liquid-chitosan grafted mPEG was designed and used for targeted multidrug delivery of DOX and MTX as model anticancer agents to MCF7 breast cancer cells. The results of hemolysis assay on human red blood cells and cytotoxicity studies indicated that blank nanocarrier has no significant hemolytic and cytotoxic effects in MCF7 cells as observed in the results of MTT assay, however, drugs-loaded nanocarrier could decrease the viability of MCF7 cells in a dose-dependent manner. To further simulate the interaction of nanocarrier with plasma proteins, the SDS-PAGE assay was performed after the nanocarrier was incubated with human plasma and the results indicated that a series of proteins were attached to the surface of nanocarrier leading protein-particle corona complex. This complex gives a stealth property as well as increasing cellular uptake process due to the presence of proteins acting as ligands for receptors in the surface of cancer cells that are suitable for drug delivery systems. The efficiency of dual-drug delivery was also confirmed by cellular uptake and DAPI staining. All these results persuade us, this nanocarrier is suitable for use in further animal studies in future investigations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrosteric stealth Rivastigmine loaded liposomes for brain targeting: preparation, characterization, ex vivo, bio-distribution and in vivo pharmacokinetic studies.

PubMed

Nageeb El-Helaly, Sara; Abd Elbary, Ahmed; Kassem, Mohamed A; El-Nabarawi, Mohamed A

2017-11-01

Being one of the highly effective drugs in treatment of Alzheimer's disease, Rivastigmine brain targeting is highly demandable, therefore liposomal dispersion of Rivastigmine was prepared containing 2 mol% PEG-DSPE added to Lecithin, Didecyldimethyl ammonium bromide (DDAB), Tween 80 in 1:0.02:0.25 molar ratio. A major challenge during the preparation of liposomes is maintaining a stable formulation, therefore the aim of our study was to increase liposomal stability by addition of DDAB to give an electrostatic stability and PEG-DSPE to increase stability by steric hindrance, yielding what we called an electrosteric stealth (ESS) liposomes. A medium nano-sized liposome (478 ± 4.94 nm) with a nearly neutral zeta potential (ZP, -8 ± 0.2 mV) and an entrapment efficiency percentage of 48 ± 6.22 was prepared. Stability studies showed no major alteration after three months storage period concerning particle size, polydispersity index, ZP, entrapment efficiency and in vitro release study confirming the successful formation of a stable liposomes. No histopathological alteration was recorded for ESS liposomes of the sheep nasal mucosa. While ESS liposomes showed higher % of drug permeating through the sheep nasal mucosa (48.6%) than the drug solution (28.7%). On completing the in vivo pharmacokinetic studies of 36 rabbits showed 424.2% relative bioavailability of the mean plasma levels of the formula ESS compared to that of RHT intranasal solution and 486% relative bioavailability of the mean brain levels.

Interactive navigation-guided ophthalmic plastic surgery: the techniques and utility of 3-dimensional navigation.

PubMed

Ali, Mohammad Javed; Naik, Milind N; Kaliki, Swathi; Dave, Tarjani Vivek; Dendukuri, Gautam

2017-06-01

To demonstrate the techniques and utility of 3-dimensional reconstruction (3DR) of the target pathologies for subsequent navigation guidance in ophthalmic plastic surgery. Prospective interventional case series. Stereotactic surgeries using 3D reconstruction of target lesions as the intraoperative image-guiding tool were performed in 5 patients with varied etiopathologies. All the surgeries were performed using the intraoperative image-guided StealthStation system in the electromagnetic mode. 3DR was performed using StealthStation 3D model software. The utility of 3D reconstruction for extensive orbital mass lesions, large orbital fractures, intraconal foreign body, and delineation of perilesional intricate structures was studied. The intraoperative ease and usefulness for the navigation of a 3D lesion at crucial phases of the surgery were noted. Intraoperative geometric localization of the 3D lesions was found to be enhanced and precise. 3D reconstruction of the lesion along with the major vessels and nerves in the vicinity helped the surgeon to prevent potential injuries to these structures. The fracture defects could be navigated in a 3D plane and this helped in moderate customization of the implants intraoperatively. Foreign body located in difficult access positions could be accurately targeted for geometric localization before safe retrieval. Detailed preoperative 3D reconstruction by the surgeon was found to be beneficial for successful outcomes. Three-dimensional navigation is very useful in providing detailed anatomical delineation of the targets and enhances the precision in certain complex cases in ophthalmic plastic surgery. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Design of a wide-band metamaterial absorber based on fractal frequency selective surface and resistive films

NASA Astrophysics Data System (ADS)

Cheng, Yong-Zhi; Nie, Yan; Gong, Rong-Zhou

2013-10-01

We present the design of a wide-band metamaterial absorber, based on fractal frequency selective surface and resistive films. The total thickness is only 0.8 mm and shows a polarization-insensitive and wide-angle strong absorption. Due to the multiband resonance properties of the Minkowski fractal loop structure and Ohmic loss properties of resistive films, a strongly absorptive bandwidth of about 19 GHz is demonstrated numerically in the range 6.51-25.42 GHz. This design provides an effective and feasible way to construct a broad-band absorber in stealth technology.

Homogenous isotropic invisible cloak based on geometrical optics.

PubMed

Sun, Jingbo; Zhou, Ji; Kang, Lei

2008-10-27

Invisible cloak derived from the coordinate transformation requires its constitutive material to be anisotropic. In this work, we present a cloak of graded-index isotropic material based on the geometrical optics theory. The cloak is realized by concentric multilayered structure with designed refractive index to achieve the low-scattering and smooth power-flow. Full-wave simulations on such a design of a cylindrical cloak are performed to demonstrate the cloaking ability to incident wave of any polarization. Using normal nature material with isotropy and low absorption, the cloak shows light on a practical path to stealth technology, especially that in the optical range.

Legionnaire's Disease: Cardiac Manifestations.

PubMed

Brusch, John L

2017-03-01

Most cardiac infections with Legionella are secondary to bacteremias arising from a pulmonary focus. Other possible sites of origin are infected sternotomy wounds or equipment contaminated by Legionella spp. Legionella endocarditis is truly a "stealth" infection, with almost no hallmarks of bacterial endocarditis. The key step in making the diagnosis of Legionella endocarditis is for the physician to be aware of the clinical causes of culture-negative infective endocarditis and to include Legionella cardiac involvement in this differential. Many times the issue of endocarditis arises only on examination of resected valvular material. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of Two Electromagnetic Navigation Systems For CT-Guided Punctures: A Phantom Study.

PubMed

Putzer, D; Arco, D; Schamberger, B; Schanda, F; Mahlknecht, J; Widmann, G; Schullian, P; Jaschke, W; Bale, R

2016-05-01

We compared the targeting accuracy and reliability of two different electromagnetic navigation systems for manually guided punctures in a phantom. CT data sets of a gelatin filled plexiglass phantom were acquired with 1, 3, and 5 mm slice thickness. After paired-point registration of the phantom, a total of 480 navigated stereotactic needle insertions were performed manually using electromagnetic guidance with two different navigation systems (Medtronic Stealth Station: AxiEM; Philips: PercuNav). A control CT was obtained to measure the target positioning error between the planned and actual needle trajectory. Using the Philips PercuNav, the accomplished Euclidean distances were 4.42 ± 1.33 mm, 4.26 ± 1.32 mm, and 4.46 ± 1.56 mm at a slice thickness of 1, 3, and 5 mm, respectively. The mean lateral positional errors were 3.84 ± 1.59 mm, 3.84 ± 1.43 mm, and 3.81 ± 1.71 mm, respectively. Using the Medtronic Stealth Station AxiEM, the Euclidean distances were 3.86 ± 2.28 mm, 3.74 ± 2.1 mm, and 4.81 ± 2.07 mm at a slice thickness of 1, 3, and 5 mm, respectively. The mean lateral positional errors were 3.29 ± 1.52 mm, 3.16 ± 1.52 mm, and 3.93 ± 1.68 mm, respectively. Both electromagnetic navigation devices showed excellent results regarding puncture accuracy in a phantom model. The Medtronic Stealth Station AxiEM provided more accurate results in comparison to the Philips PercuNav for CT with 3 mm slice thickness. One potential benefit of electromagnetic navigation devices is the absence of visual contact between the instrument and the sensor system. Due to possible interference with metal objects, incorrect position sensing may occur. In contrast to the phantom study, patient movement including respiration has to be compensated for in the clinical setting. • Commercially available electromagnetic navigation systems have the potential to improve the therapeutic range for CT guided percutaneous procedures by comparing the needle placement accuracy on the basis of planning CT data sets with different slice thickness. Citation Format: • Putzer D, Arco D, Schamberger B et al. Comparison of Two Electromagnetic Navigation Systems For CT-Guided Punctures: A Phantom Study. Fortschr Röntgenstr 2016; 188: 470 - 478. © Georg Thieme Verlag KG Stuttgart · New York.

C1q-Mediated Complement Activation and C3 Opsonization Trigger Recognition of Stealth Poly(2-methyl-2-oxazoline)-Coated Silica Nanoparticles by Human Phagocytes.

PubMed

Tavano, Regina; Gabrielli, Luca; Lubian, Elisa; Fedeli, Chiara; Visentin, Silvia; Polverino De Laureto, Patrizia; Arrigoni, Giorgio; Geffner-Smith, Alessandra; Chen, Fangfang; Simberg, Dmitri; Morgese, Giulia; Benetti, Edmondo M; Wu, Linping; Moghimi, Seyed Moein; Mancin, Fabrizio; Papini, Emanuele

2018-05-23

Poly(2-methyl-2-oxazoline) (PMOXA) is an alternative promising polymer to poly(ethylene glycol) (PEG) for design and engineering of macrophage-evading nanoparticles (NPs). Although PMOXA-engineered NPs have shown comparable pharmacokinetics and in vivo performance to PEGylated stealth NPs in the murine model, its interaction with elements of the human innate immune system has not been studied. From a translational angle, we studied the interaction of fully characterized PMOXA-coated vinyltriethoxysilane-derived organically modified silica NPs (PMOXA-coated NPs) of approximately 100 nm in diameter with human complement system, blood leukocytes, and macrophages and compared their performance with PEGylated and uncoated NP counterparts. Through detailed immunological and proteomic profiling, we show that PMOXA-coated NPs extensively trigger complement activation in human sera exclusively through the classical pathway. Complement activation is initiated by the sensing molecule C1q, where C1q binds with high affinity ( K d = 11 ± 1 nM) to NP surfaces independent of immunoglobulin binding. C1q-mediated complement activation accelerates PMOXA opsonization with the third complement protein (C3) through the amplification loop of the alternative pathway. This promoted NP recognition by human blood leukocytes and monocyte-derived macrophages. The macrophage capture of PMOXA-coated NPs correlates with sera donor variability in complement activation and opsonization but not with other major corona proteins, including clusterin and a wide range of apolipoproteins. In contrast to these observations, PMOXA-coated NPs poorly activated the murine complement system and were marginally recognized by mouse macrophages. These studies provide important insights into compatibility of engineered NPs with elements of the human innate immune system for translational steps.

[Atelocollagen-mediated small interfering RNA delivery for effective gene silencing in rat vein grafts].

PubMed

Qiu, Xue-feng; Dong, Nian-guo; Sun, Zong-quan; Su, Wei; Shi, Jia-wei

2009-07-01

To evaluate the efficacy of using small interfering RNA targeting TF as a therapy for vein graft failure. External jugular vein to carotid artery interposition vein grafts, which were applied to a low flow condition, were made in 120 Sprague-Dawley rats weighing 260 to 300 g. These rats were randomly divided into 4 groups, 30 rats each group. Group A was atelocollagen-TF Stealth Select RNAi group. Group B was atelocollagen-TF Stealth RNAi group. Group C was atelocollagen group. Group D was control group. Small interfering RNA mixed with atelocollagen was administrated to the external wall of grafted veins. The TF protein expression of vein grafts was analyzed by Western blot at 1, 3, 7, 14, and 28 d postoperatively, and by immunochemistry at 3 d postoperatively. The proliferation index was determined at 14 d postoperatively. Neointimal hyperplasia was evaluated at 28 d postoperatively. BLOCK-iT fluorescent oligo was used to confirm its stability and successful transfer into the vein graft wall at 3 and 7 d postoperatively for another group (n=12). Fluorescence of BLOCK-iT fluorescent oligo could be detected in the graft wall even at 7 d postoperatively. Knockdown of the TF expression was achieved by perivascular application of siRNA using atelocollagen. Compared with control group, the intima thickness at 28 d after grafting was significantly reduced (P < 0.05). This phenomenon was preceded by significant reduction of cell proliferation in siRNA-treated grafts at 14 d postoperatively (P < 0.05). The expression of TF in vein grafts can be effectively inhibited by specific siRNAs using a atelocollagen-based nonviral delivery approach in vivo, so that the neointimal thickening can be prevented. Transplants;

"Stealth and Fully-Laden" Drug Carriers: Self-Assembled Nanogels Encapsulated with Epigallocatechin Gallate and siRNA for Drug-Resistant Breast Cancer Therapy.

PubMed

Ding, Jie; Liang, Tingxizi; Min, Qianhao; Jiang, Liping; Zhu, Jun-Jie

2018-03-28

For codelivery of therapeutic genes and chemical agents in combined therapy, the ideal drug delivery system entails high-capacity and low-body toxicity carriers, allowing adequate drug dose for tumor regions while yielding low residues in normal tissues. To augment the gene/drug load capacity and circumvent the potential toxicity brought by traditional inorganic and polymeric nanocarriers, a "stealth" carrier was herein designed in a simple self-assembly of (-)-epigallocatechin-3- O-gallate (EGCG) and small interfering RNA (siRNA) by recruiting protamine as a biodegradable medium for the treatment of drug-resistant triple-negative breast cancer. In the self-assembled nanogel, entrapped siRNA played a central role in sensitizing the tumor response to EGCG-involved chemotherapy, and the positively charged protamine served as the assembly skeleton to fully accommodate gene and drug molecules and minimize the factors causing side effects. As compared to stand-alone chemotherapy with EGCG, the multicomponent nanogel revealed a 15-fold increase in the cytotoxicity to drug-resistant MDA-MB-231 cell line. Moreover, equipped with hyaluronic acid and tumor-homing cell-penetrating peptide as the outmost targeting ligands, the siRNA- and EGCG-loaded nanogel demonstrates superior selectivity and tumor growth inhibition to free EGCG in xenograft MDA-MB-231 tumor-bearing mice. Meanwhile, thanks to the acknowledged biosafety of protamine, little toxicity was found to normal tissues and organs in the animal model. This gene/drug self-assembly caged in a biodegradable carrier opens up an effective and secure route for drug-resistant cancer therapy and provides a versatile approach for codelivery of other genes and drugs for different medical purposes.

Creating an arsenal of Adeno-associated virus (AAV) gene delivery stealth vehicles.

PubMed

Smith, J Kennon; Agbandje-McKenna, Mavis

2018-05-01

The Adeno-associated virus (AAV) gene delivery system is ushering in a new and exciting era in the United States; following the first approved gene therapy (Glybera) in Europe, the FDA has approved a second therapy, Luxturna [1]. However, challenges to this system remain. In viral gene therapy, the surface of the capsid is an important determinant of tissue tropism, impacts gene transfer efficiency, and is targeted by the human immune system. Preexisting immunity is a significant challenge to this approach, and the ability to visualize areas of antibody binding ("footprints") can inform efforts to improve the efficacy of viral vectors. Atomic resolution, smaller proteins, and asymmetric structures are the goals to attain in cryo-electron microscopy and image reconstruction (cryo-EM) as of late. The versatility of the technique and the ability to vitrify a wide range of heterogeneous molecules in solution allow structural biologists to characterize a variety of protein-DNA and protein-protein interactions at lower resolution. Cryo-EM has served as an important means to study key surface areas of the AAV gene delivery vehicle-specifically, those involved with binding neutralizing antibodies (NAbs) [2-4]. This method offers a unique opportunity for visualizing antibody binding "hotspots" on the surface of these and other viral vectors. When combined with mutagenesis, one can eliminate these hotspots to create viral vectors with the ability to avoid preexisting host immune recognition during gene delivery and genetic defect correction in disease treatment. Here, we discuss the use of structure-guided site-directed mutagenesis and directed evolution to create "stealth" AAV vectors with modified surface amino acid sequences that allow NAb avoidance while maintaining natural capsid functions or gaining desired novel tropisms.

Distribution and Correlates of Self-Reported Crimes of Trust.

PubMed

Menard, Scott; Morris, Robert G; Gerber, Jurg; Covey, Herbert C

2011-11-01

This study examines the distribution and correlates of a special class of property crimes, crimes of trust, using longitudinal and cross sectional self-report data from a national sample. We begin by defining crimes of trust and consider their conceptual relationship to "conventional" property crimes, which we here characterize as crimes of stealth, and to white collar crimes, which are defined in terms of the social status of the perpetrators. Crimes of trust are here defined as property crimes that typically involve deliberate contact with the victim or, where there is more than one victim, with at least one or more victims, in which there is typically more of a focus on concealing the fact that a crime has been committed than on concealing the identity of the perpetrator (as is the case in crimes of stealth), without regard to the socioeconomic status of the perpetrator (thus including but not limited to white collar crimes). The focus here is on crimes of trust committed by individuals (as opposed to corporate crime). We first examine their distribution by sociodemographic characteristics, then examine the correlation of crimes of trust with other types of illegal behavior, using data from the National Youth Survey Family Study, including (1) longitudinal self-report data from a nationally representative panel of individuals who were 11-18 years old in 1976-77 and who were followed through early middle age (ages 36-44) in 2002-2003, plus (2) cross-sectional data on these individuals plus their parents, spouses, and children age 11 and older in 2002-2003 (total age range 11-88). The results suggest that crimes of trust have a different age-crime curve from conventional crimes, and that they are not as strongly correlated with problem substance use, gender, and other socioeconomic indicators as conventional crimes.

Children as consumers: advertising and marketing.

PubMed

Calvert, Sandra L

2008-01-01

Marketing and advertising support the U.S. economy by promoting the sale of goods and services to consumers, both adults and children. Sandra Calvert addresses product marketing to children and shows that although marketers have targeted children for decades, two recent trends have increased their interest in child consumers. First, both the discretionary income of children and their power to influence parent purchases have increased over time. Second, as the enormous increase in the number of available television channels has led to smaller audiences for each channel, digital interactive technologies have simultaneously opened new routes to narrow cast to children, thereby creating a growing media space just for children and children's products. Calvert explains that paid advertising to children primarily involves television spots that feature toys and food products, most of which are high in fat and sugar and low in nutritional value. Newer marketing approaches have led to online advertising and to so-called stealth marketing techniques, such as embedding products in the program content in films, online, and in video games. All these marketing strategies, says Calvert, make children younger than eight especially vulnerable because they lack the cognitive skills to understand the persuasive intent of television and online advertisements. The new stealth techniques can also undermine the consumer defenses even of older children and adolescents. Calvert explains that government regulations implemented by the Federal Communications Commission and the Federal Trade Commission provide some protection for children from advertising and marketing practices. Regulators exert more control over content on scarce television airwaves that belong to the public than over content on the more open online spaces. Overall, Calvert concludes, children live and grow up in a highly sophisticated marketing environment that influences their preferences and behaviors.

Spontaneous temperature-sensitive Pluronic(®) based niosomes: Triggered drug release using mild hyperthermia.

PubMed

Tavano, Lorena; Oliviero Rossi, Cesare; Picci, Nevio; Muzzalupo, Rita

2016-09-25

Inclusion of lipids or polymers with a transition temperature closer to physiological body temperature (40-42°C) is a strategy used in tumor therapy for more than 30 years, because it allows induction of drug release from delivery systems by mild hyperthermia. Unfortunately, most of these thermo-sensitive carriers are removed from circulation before completion of their function. Thus, novel multi-functional niosomes possessing spontaneous stealth and thermo-sensitive properties were developed from L64 Pluronic(®) and L64ox as its derivative, in presence or absence of cholesterol. The use of L64 both as amphiphilic constituent and thermo-sensitive molecule, gave the possibility to bypass the use of additional excipients and increased the system biocompatibility. Niosomes diameter ranged from 400 to 750nm and were long term stable. Calcein and 5-FU possess great affinity to niosomal matrices rich in PEO groups. Negative Z-potential values were attributed to the negative charges onto the niosomes surface and generally change according to the temperature. The in vitro drugs release studies were performed at 25°C, 37°C and 42°C, that are representative of certain conditions (storage, physiological condition and mild hyperthermia, respectively). Results showed that L64-based niosomes possess spontaneous thermo-sensitive properties: drugs releases were found to be more pronounced at 42°C. These early results are a promising first step for the development of multi-functional devices that combine several advantages such as stealth properties and temperature controllability at the desired location and time, for a more specific and efficient pharmacological therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Multifunctional iron platinum stealth immunomicelles: targeted detection of human prostate cancer cells using both fluorescence and magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Taylor, Robert M.; Huber, Dale L.; Monson, Todd C.; Ali, Abdul-Mehdi S.; Bisoffi, Marco; Sillerud, Laurel O.

2011-10-01

Superparamagnetic iron oxide nanoparticles (SPIONs) are the most common type of contrast agents used in contrast agent-enhanced magnetic resonance imaging (MRI). Still, there is a great deal of room for improvement, and nanoparticles with increased MRI relaxivities are needed to increase the contrast enhancement in MRI applied to various medical conditions including cancer. We report the synthesis of superparamagnetic iron platinum nanoparticles (SIPPs) and subsequent encapsulation using PEGylated phospholipids to create stealth immunomicelles (DSPE-SIPPs) that can be specifically targeted to human prostate cancer cell lines and detected using both MRI and fluorescence imaging. SIPP cores and DSPE-SIPPs were 8.5 ± 1.6 nm and 42.9 ± 8.2 nm in diameter, respectively, and the SIPPs had a magnetic moment of 120 A m2/kg iron. J591, a monoclonal antibody against prostate specific membrane antigen (PSMA), was conjugated to the DSPE-SIPPs (J591-DSPE-SIPPs), and specific targeting of J591-DSPE-SIPPs to PSMA-expressing human prostate cancer cell lines was demonstrated using fluorescence confocal microscopy. The transverse relaxivity of the DSPE-SIPPs, measured at 4.7 Tesla, was 300.6 ± 8.5 s-1 mM-1, which is 13-fold better than commercially available SPIONs (23.8 ± 6.9 s-1 mM-1) and 3-fold better than reported relaxivities for Feridex® and Resovist®. Our data suggest that J591-DSPE-SIPPs specifically target human prostate cancer cells in vitro, are superior contrast agents in T 2-weighted MRI, and can be detected using fluorescence imaging. To our knowledge, this is the first report on the synthesis of multifunctional SIPP micelles and using SIPPs for the specific detection of prostate cancer.

Distribution of PLGA-modified nanoparticles in 3D cell culture models of hypo-vascularized tumor tissue.

PubMed

Sims, Lee B; Huss, Maya K; Frieboes, Hermann B; Steinbach-Rankins, Jill M

2017-10-05

Advanced stage cancer treatments are often invasive and painful-typically comprised of surgery, chemotherapy, and/or radiation treatment. Low transport efficiency during systemic chemotherapy may require high chemotherapeutic doses to effectively target cancerous tissue, resulting in systemic toxicity. Nanotherapeutic platforms have been proposed as an alternative to more safely and effectively deliver therapeutic agents directly to tumor sites. However, cellular internalization and tumor penetration are often diametrically opposed, with limited access to tumor regions distal from vasculature, due to irregular tissue morphologies. To address these transport challenges, nanoparticles (NPs) are often surface-modified with ligands to enhance transport and longevity after localized or systemic administration. Here, we evaluate stealth polyethylene-glycol (PEG), cell-penetrating (MPG), and CPP-stealth (MPG/PEG) poly(lactic-co-glycolic-acid) (PLGA) NP co-treatment strategies in 3D cell culture representing hypo-vascularized tissue. Smaller, more regularly-shaped avascular tissue was generated using the hanging drop (HD) method, while more irregularly-shaped masses were formed with the liquid overlay (LO) technique. To compare NP distribution differences within the same type of tissue as a function of different cancer types, we selected HeLa, cervical epithelial adenocarcinoma cells; CaSki, cervical epidermoid carcinoma cells; and SiHa, grade II cervical squamous cell carcinoma cells. In HD tumors, enhanced distribution relative to unmodified NPs was measured for MPG and PEG NPs in HeLa, and for all modified NPs in SiHa spheroids. In LO tumors, the greatest distribution was observed for MPG and MPG/PEG NPs in HeLa, and for PEG and MPG/PEG NPs in SiHa spheroids. Pre-clinical evaluation of PLGA-modified NP distribution into hypo-vascularized tumor tissue may benefit from considering tissue morphology in addition to cancer type.

D-Optimal mixture experimental design for stealth biodegradable crosslinked docetaxel-loaded poly-ε-caprolactone nanoparticles manufactured by dispersion polymerization.

PubMed

Ogunwuyi, O; Adesina, S; Akala, E O

2015-03-01

We report here our efforts on the development of stealth biodegradable crosslinked poly-ε-caprolactone nanoparticles by free radical dispersion polymerization suitable for the delivery of bioactive agents. The uniqueness of the dispersion polymerization technique is that it is surfactant free, thereby obviating the problems known to be associated with the use of surfactants in the fabrication of nanoparticles for biomedical applications. Aided by a statistical software for experimental design and analysis, we used D-optimal mixture statistical experimental design to generate thirty batches of nanoparticles prepared by varying the proportion of the components (poly-ε-caprolactone macromonomer, crosslinker, initiators and stabilizer) in acetone/water system. Morphology of the nanoparticles was examined using scanning electron microscopy (SEM). Particle size and zeta potential were measured by dynamic light scattering (DLS). Scheffe polynomial models were generated to predict particle size (nm) and particle surface zeta potential (mV) as functions of the proportion of the components. Solutions were returned from simultaneous optimization of the response variables for component combinations to (a) minimize nanoparticle size (small nanoparticles are internalized into disease organs easily, avoid reticuloendothelial clearance and lung filtration) and (b) maximization of the negative zeta potential values, as it is known that, following injection into the blood stream, nanoparticles with a positive zeta potential pose a threat of causing transient embolism and rapid clearance compared to negatively charged particles. In vitro availability isotherms show that the nanoparticles sustained the release of docetaxel for 72 to 120 hours depending on the formulation. The data show that nanotechnology platforms for controlled delivery of bioactive agents can be developed based on the nanoparticles.

Implementation of QoSS (Quality-of-Security Service) for NoC-Based SoC Protection

NASA Astrophysics Data System (ADS)

Sepúlveda, Johanna; Pires, Ricardo; Strum, Marius; Chau, Wang Jiang

Many of the current electronic systems embedded in a SoC (System-on-Chip) are used to capture, store, manipulate and access critical data, as well as to perform other key functions. In such a scenario, security is considered as an important issue. The Network-on-chip (NoC), as the foreseen communication structure of next-generation SoC devices, can be used to efficiently incorporate security. Our work proposes the implementation of QoSS (Quality of Security Service) to overcome present SoC vulnerabilities. QoSS is a novel concept for data protection that introduces security as a dimension of QoS. In this paper, we present the implementation of two security services (access control and authentication), that may be configured to assume one from several possible levels, the implementation of a technique to avoid denial-of-service (DoS) attacks, evaluate their effectiveness and estimate their impact on NoC performance.

The expectation of applying IR guidance in medium range air-to-air missiles

NASA Astrophysics Data System (ADS)

Li, Lijuan; Liu, Ke

2016-10-01

IR guidance has been widely used in near range dogfight air-to-air missiles while radar guidance is dominant in medium and long range air-to-air missiles. With the development of stealth airplanes and advanced electronic countermeasures, radar missiles have met with great challenges. In this article, the advantages and potential problems of applying IR guidance in medium range air-to-air missiles are analyzed. Approaches are put forward to solve the key technologies including depressing aerodynamic heating, increasing missiles' sensitivity and acquiring target after launch. IR medium range air-to-air missiles are predicted to play important role in modern battle field.

Advancing Global Health – The Need for (Better) Social Science

PubMed Central

Hanefeld, Johanna

2016-01-01

In his perspective "Navigating between stealth advocacy and unconscious dogmatism: the challenge of researching the norms, politics and power of global health," Ooms argues that actions taken in the field of global health are dependent not only on available resources, but on the normative premise that guides how these resources are spent. This comment sets out how the application of a predominately biomedical positivist research tradition in global health, has potentially limited understanding of the value judgements underlying decisions in the field. To redress this critical social science, including health policy analysis has much to offer, to the field of global health including on questions of governance. PMID:27239873

Applying a Consumer Behavior Lens to Salt Reduction Initiatives.

PubMed

Regan, Áine; Kent, Monique Potvin; Raats, Monique M; McConnon, Áine; Wall, Patrick; Dubois, Lise

2017-08-18

Reformulation of food products to reduce salt content has been a central strategy for achieving population level salt reduction. In this paper, we reflect on current reformulation strategies and consider how consumer behavior determines the ultimate success of these strategies. We consider the merits of adopting a 'health by stealth', silent approach to reformulation compared to implementing a communications strategy which draws on labeling initiatives in tandem with reformulation efforts. We end this paper by calling for a multi-actor approach which utilizes co-design, participatory tools to facilitate the involvement of all stakeholders, including, and especially, consumers, in making decisions around how best to achieve population-level salt reduction.

Secure and Efficient Two-Factor User Authentication Scheme with User Anonymity for Network Based E-Health Care Applications.

PubMed

Li, Xiong; Niu, Jianwei; Karuppiah, Marimuthu; Kumari, Saru; Wu, Fan

2016-12-01

Benefited from the development of network and communication technologies, E-health care systems and telemedicine have got the fast development. By using the E-health care systems, patient can enjoy the remote medical service provided by the medical server. Medical data are important privacy information for patient, so it is an important issue to ensure the secure of transmitted medical data through public network. Authentication scheme can thwart unauthorized users from accessing services via insecure network environments, so user authentication with privacy protection is an important mechanism for the security of E-health care systems. Recently, based on three factors (password, biometric and smart card), an user authentication scheme for E-health care systems was been proposed by Amin et al., and they claimed that their scheme can withstand most of common attacks. Unfortunate, we find that their scheme cannot achieve the untraceability feature of the patient. Besides, their scheme lacks a password check mechanism such that it is inefficient to find the unauthorized login by the mistake of input a wrong password. Due to the same reason, their scheme is vulnerable to Denial of Service (DoS) attack if the patient updates the password mistakenly by using a wrong password. In order improve the security level of authentication scheme for E-health care application, a robust user authentication scheme with privacy protection is proposed for E-health care systems. Then, security prove of our scheme are analysed. Security and performance analyses show that our scheme is more powerful and secure for E-health care systems when compared with other related schemes.

Robustness of non-interdependent and interdependent networks against dependent and adaptive attacks

NASA Astrophysics Data System (ADS)

Tyra, Adam; Li, Jingtao; Shang, Yilun; Jiang, Shuo; Zhao, Yanjun; Xu, Shouhuai

2017-09-01

Robustness of complex networks has been extensively studied via the notion of site percolation, which typically models independent and non-adaptive attacks (or disruptions). However, real-life attacks are often dependent and/or adaptive. This motivates us to characterize the robustness of complex networks, including non-interdependent and interdependent ones, against dependent and adaptive attacks. For this purpose, dependent attacks are accommodated by L-hop percolation where the nodes within some L-hop (L ≥ 0) distance of a chosen node are all deleted during one attack (with L = 0 degenerating to site percolation). Whereas, adaptive attacks are launched by attackers who can make node-selection decisions based on the network state in the beginning of each attack. The resulting characterization enriches the body of knowledge with new insights, such as: (i) the Achilles' Heel phenomenon is only valid for independent attacks, but not for dependent attacks; (ii) powerful attack strategies (e.g., targeted attacks and dependent attacks, dependent attacks and adaptive attacks) are not compatible and cannot help the attacker when used collectively. Our results shed some light on the design of robust complex networks.

Broadband metamaterial as an "invisible" radiative cooling coat

NASA Astrophysics Data System (ADS)

Huang, Yijia; Pu, Mingbo; Zhao, Zeyu; Li, Xiong; Ma, Xiaoliang; Luo, Xiangang

2018-01-01

In this paper, we propose a compact planar device in infrared (3- 12 μm) that has a high emission range from 5 μm to 8 μm while simultaneously serving as a broadband mirror for the rest wavelengths by engineering its thermal emission characteristics. The structure utilizes a random-stacked multilayer to reduce the thickness required for ideal spectrum engineering. In addition, it is also convenient to fabricate and scale up. All the features above makes it an ;invisible; radiative cooling coat by taking advantage of the atmospheric transparency window. We believe that this device may fundamentally enable new technological possibilities for stealth techniques by integrating the device with traditional cloaking methods.

An optimal control strategy for two-dimensional motion camouflage with non-holonimic constraints.

PubMed

Rañó, Iñaki

2012-07-01

Motion camouflage is a stealth behaviour observed both in hover-flies and in dragonflies. Existing controllers for mimicking motion camouflage generate this behaviour on an empirical basis or without considering the kinematic motion restrictions present in animal trajectories. This study summarises our formal contributions to solve the generation of motion camouflage as a non-linear optimal control problem. The dynamics of the system capture the kinematic restrictions to motion of the agents, while the performance index ensures camouflage trajectories. An extensive set of simulations support the technique, and a novel analysis of the obtained trajectories contributes to our understanding of possible mechanisms to obtain sensor based motion camouflage, for instance, in mobile robots.

Review on Variable Emissivity Materials and Devices Based on Smart Chromism

NASA Astrophysics Data System (ADS)

Lang, FengPei; Wang, Hao; Zhang, ShengJun; Liu, JingBing; Yan, Hui

2018-01-01

Variable emissivity material (VEM) can dynamically vary its emissivity and infrared radiation under certain conditions, which may find potential applications in infrared stealth/camouflage, solar thermal collector, spacecraft thermal control, and smart energy-saving windows. In this paper, the variable emissivity materials and devices based on electrochromism and thermochromism are introduced. The basic principle and present status of the research in these fields are overviewed. Four kinds of representative VEMs are extensively summarized, which are tungsten trioxides (WO3), conducting polymers (CPs), perovskite oxides (A_{1-{x}}B_{{x}}MO3), and vanadium dioxide (VO2). Finally, specific issues confronted with electrochromic and thermochromic materials and devices are prospected.

Consumer-driven healthcare marketing: using the web to get up close and personal.

PubMed

Rooney, Keila

2009-01-01

This essay examines the emergence of consumer-driven healthcare marketing, including its operational definition, how it has been used in the past, and how it has evolved. Specifically, marketing practices in other industries are inspected to understand the factors that have contributed to their successes and to determine the relevance of these efforts to healthcare marketing. The advantages of new, technology-enabled marketing opportunities are considered as well, such as stealth ads, blogs, podcasts, and corporate participation in social networks. The implications of the regulation on healthcare websites, along with the work-around strategies used, are analyzed. Lastly, the essay submits recommendations for the healthcare executive when implementing a consumer-driven healthcare marketing plan.

Flexible metamaterial absorbers for stealth applications at terahertz frequencies.

PubMed

Iwaszczuk, Krzysztof; Strikwerda, Andrew C; Fan, Kebin; Zhang, Xin; Averitt, Richard D; Jepsen, Peter Uhd

2012-01-02

We have wrapped metallic cylinders with strongly absorbing metamaterials. These resonant structures, which are patterned on flexible substrates, smoothly coat the cylinder and give it an electromagnetic response designed to minimize its radar cross section. We compare the normal-incidence, small-beam reflection coefficient with the measurement of the far-field bistatic radar cross section of the sample, using a quasi-planar THz wave with a beam diameter significantly larger than the sample dimensions. In this geometry we demonstrate a near-400-fold reduction of the radar cross section at the design frequency of 0.87 THz. In addition we discuss the effect of finite sample dimensions and the spatial dependence of the reflection spectrum of the metamaterial.

Improvement on RCS reduction using flat lossy focusing reflectors.

PubMed

Chin, Cheng-Yuan; Jou, Christina F

2013-12-30

In this paper, we propose a planar non-periodic subwavelength resistive grating (SWRG). The phase front of the scattered fields can be completely manipulated through non-periodic design of the grating while high absorptivity is preserved. The SWRG has an interesting property similar to a resistive concave reflecting lens. Scattered wave is focused in the near-field region, and spread out in the far-field. This feature of non-periodic resistive grating can improve the original radar cross section (RCS) reduction up to 22.86 dB in the boresight direction comparing to the periodic counterpart. Non-periodic design of SWRG could have a substantial impact on stealth technology, aerospace engineering, and microwave anechoic chamber.

Optical emission spectroscopy as a tool for the biodistribution investigation of cobalt-ferrite nanoparticles in mice

NASA Astrophysics Data System (ADS)

Kückelhaus, S.; Tedesco, A. C.; Oliveira, D. M.; Morais, P. C.; Boaventura, G. R.; Lacava, Z. G. M.

2005-05-01

This study reports on the biodistribution investigation of two magnetic samples both based on cobalt-ferrite nanoparticles, a magnetic fluid sample (CoMF) and a stealth magnetoliposome polyethylene glycol-monolaurate (PEG-ML). Morphology observations and iron and cobalt concentrations were evaluated after treatment of mice upon intravenous injection. Both magnetic samples had an extended distribution throughout all investigated organs. CoMF was quickly eliminated mainly by the fecal via whereas PEG-ML was retained longer in the circulation and slowly eliminated. These differences are probably due to the presence of polyethylene glycol on the PEG-ML surface, recognized to be responsible for the internalization delay of nanoparticles.

The contribution of collective attack tactics in differentiating handball score efficiency.

PubMed

Rogulj, Nenad; Srhoj, Vatromir; Srhoj, Ljerka

2004-12-01

The prevalence of 19 elements of collective tactics in score efficient and score inefficient teams was analyzed in 90 First Croatian Handball League--Men games during the 1998-1999 season. Prediction variables were used to describe duration, continuity, system, organization and spatial direction of attacks. Analysis of the basic descriptive and distribution statistical parameters revealed normal distribution of all variables and possibility to use multivariate methods. Canonic discrimination analysis and analysis of variance showed the use of collective tactics elements on attacks to differ statistically significantly between the winning and losing teams. Counter-attacks and uninterrupted attacks predominate in winning teams. Other types of attacks such as long position attack, multiply interrupted attack, attack with one circle runner attack player/pivot, attack based on basic principles, attack based on group cooperation, attack based on independent action, attack based on group maneuvering, rightward directed attack and leftward directed attack predominate in losing teams. Winning teams were found to be clearly characterized by quick attacks against unorganized defense, whereas prolonged, interrupted position attacks against organized defense along with frequent and diverse tactical actions were characteristic of losing teams. The choice and frequency of using a particular tactical activity in position attack do not warrant score efficiency but usually are consequential to the limited anthropologic potential and low level of individual technical-tactical skills of the players in low-quality teams.

Predicting Factors of Zone 4 Attack in Volleyball.

PubMed

Costa, Gustavo C; Castro, Henrique O; Evangelista, Breno F; Malheiros, Laura M; Greco, Pablo J; Ugrinowitsch, Herbert

2017-06-01

This study examined 142 volleyball games of the Men's Super League 2014/2015 seasons in Brazil from which we analyzed 24-26 games of each participating team, identifying 5,267 Zone 4 attacks for further analysis. Within these Zone 4 attacks, we analyzed the association between the effect of the attack carried out and the separate effects of serve reception, tempo and type of attack. We found that the reception, tempo of attack, second tempo of attack, and power of diagonal attack were predictors of the attack effect in Zone 4. Moreover, placed attacks showed a tendency to not yield a score. In conclusion, winning points in high-level men's volleyball requires excellent receptions, a fast attack tempo and powerfully executed of attacks.

Breakthrough attacks in patients with hereditary angioedema receiving long-term prophylaxis are responsive to icatibant: findings from the Icatibant Outcome Survey.

PubMed

Aberer, Werner; Maurer, Marcus; Bouillet, Laurence; Zanichelli, Andrea; Caballero, Teresa; Longhurst, Hilary J; Perrin, Amandine; Andresen, Irmgard

2017-01-01

Patients with hereditary angioedema (HAE) due to C1-inhibitor deficiency (C1-INH-HAE) experience recurrent attacks of cutaneous or submucosal edema that may be frequent and severe; prophylactic treatments can be prescribed to prevent attacks. However, despite the use of long-term prophylaxis (LTP), breakthrough attacks are known to occur. We used data from the Icatibant Outcome Survey (IOS) to evaluate the characteristics of breakthrough attacks and the effectiveness of icatibant as a treatment option. Data on LTP use, attacks, and treatments were recorded. Attack characteristics, treatment characteristics, and outcomes (time to treatment, time to resolution, and duration of attack) were compared for attacks that occurred with versus without LTP. Data on 3228 icatibant-treated attacks from 448 patients with C1-INH-HAE were analyzed; 30.1% of attacks occurred while patients were using LTP. Attack rate, attack severity, and the distribution of attack sites were similar across all types of LTP used, and were comparable to the results found in patients who did not receive LTP. Attacks were successfully treated with icatibant; 82.5% of all breakthrough attacks were treated with a single icatibant injection without C1-INH rescue medication. Treatment outcomes were comparable for breakthrough attacks across all LTP types, and for attacks without LTP. Patients who use LTP should be aware that breakthrough attacks can occur, and such attacks can be severe. Thus, patients with C1-INH-HAE using LTP should have emergency treatment readily available. Data from IOS show that icatibant is effective for the treatment of breakthrough attacks. Trial Registration NCT01034969.

A graph-based network-vulnerability analysis system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swiler, L.P.; Phillips, C.; Gaylor, T.

1998-05-03

This paper presents a graph based approach to network vulnerability analysis. The method is flexible, allowing analysis of attacks from both outside and inside the network. It can analyze risks to a specific network asset, or examine the universe of possible consequences following a successful attack. The analysis system requires as input a database of common attacks, broken into atomic steps, specific network configuration and topology information, and an attacker profile. The attack information is matched with the network configuration information and an attacker profile to create a superset attack graph. Nodes identify a stage of attack, for example themore » class of machines the attacker has accessed and the user privilege level he or she has compromised. The arcs in the attack graph represent attacks or stages of attacks. By assigning probabilities of success on the arcs or costs representing level of effort for the attacker, various graph algorithms such as shortest path algorithms can identify the attack paths with the highest probability of success.« less

A graph-based network-vulnerability analysis system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swiler, L.P.; Phillips, C.; Gaylor, T.

1998-01-01

This report presents a graph-based approach to network vulnerability analysis. The method is flexible, allowing analysis of attacks from both outside and inside the network. It can analyze risks to a specific network asset, or examine the universe of possible consequences following a successful attack. The analysis system requires as input a database of common attacks, broken into atomic steps, specific network configuration and topology information, and an attacker profile. The attack information is matched with the network configuration information and an attacker profile to create a superset attack graph. Nodes identify a stage of attack, for example the classmore » of machines the attacker has accessed and the user privilege level he or she has compromised. The arcs in the attack graph represent attacks or stages of attacks. By assigning probabilities of success on the arcs or costs representing level-of-effort for the attacker, various graph algorithms such as shortest-path algorithms can identify the attack paths with the highest probability of success.« less

Method and tool for network vulnerability analysis

DOEpatents

Swiler, Laura Painton [Albuquerque, NM; Phillips, Cynthia A [Albuquerque, NM

2006-03-14

A computer system analysis tool and method that will allow for qualitative and quantitative assessment of security attributes and vulnerabilities in systems including computer networks. The invention is based on generation of attack graphs wherein each node represents a possible attack state and each edge represents a change in state caused by a single action taken by an attacker or unwitting assistant. Edges are weighted using metrics such as attacker effort, likelihood of attack success, or time to succeed. Generation of an attack graph is accomplished by matching information about attack requirements (specified in "attack templates") to information about computer system configuration (contained in a configuration file that can be updated to reflect system changes occurring during the course of an attack) and assumed attacker capabilities (reflected in "attacker profiles"). High risk attack paths, which correspond to those considered suited to application of attack countermeasures given limited resources for applying countermeasures, are identified by finding "epsilon optimal paths."

About Heart Attacks

MedlinePlus

... Artery Disease Venous Thromboembolism Aortic Aneurysm More About Heart Attacks Updated:Jan 11,2018 A heart attack is ... coronary artery damage leads to a heart attack . Heart Attack Questions and Answers What is a heart attack? ...

Intrusion detection using rough set classification.

PubMed

Zhang, Lian-hua; Zhang, Guan-hua; Zhang, Jie; Bai, Ying-cai

2004-09-01

Recently machine learning-based intrusion detection approaches have been subjected to extensive researches because they can detect both misuse and anomaly. In this paper, rough set classification (RSC), a modern learning algorithm, is used to rank the features extracted for detecting intrusions and generate intrusion detection models. Feature ranking is a very critical step when building the model. RSC performs feature ranking before generating rules, and converts the feature ranking to minimal hitting set problem addressed by using genetic algorithm (GA). This is done in classical approaches using Support Vector Machine (SVM) by executing many iterations, each of which removes one useless feature. Compared with those methods, our method can avoid many iterations. In addition, a hybrid genetic algorithm is proposed to increase the convergence speed and decrease the training time of RSC. The models generated by RSC take the form of "IF-THEN" rules, which have the advantage of explication. Tests and comparison of RSC with SVM on DARPA benchmark data showed that for Probe and DoS attacks both RSC and SVM yielded highly accurate results (greater than 99% accuracy on testing set).

Knee point search using cascading top-k sorting with minimized time complexity.

PubMed

Wang, Zheng; Tseng, Shian-Shyong

2013-01-01

Anomaly detection systems and many other applications are frequently confronted with the problem of finding the largest knee point in the sorted curve for a set of unsorted points. This paper proposes an efficient knee point search algorithm with minimized time complexity using the cascading top-k sorting when a priori probability distribution of the knee point is known. First, a top-k sort algorithm is proposed based on a quicksort variation. We divide the knee point search problem into multiple steps. And in each step an optimization problem of the selection number k is solved, where the objective function is defined as the expected time cost. Because the expected time cost in one step is dependent on that of the afterwards steps, we simplify the optimization problem by minimizing the maximum expected time cost. The posterior probability of the largest knee point distribution and the other parameters are updated before solving the optimization problem in each step. An example of source detection of DNS DoS flooding attacks is provided to illustrate the applications of the proposed algorithm.

ESS-FH: Enhanced Security Scheme for Fast Handover in Hierarchical Mobile IPv6

NASA Astrophysics Data System (ADS)

You, Ilsun; Lee, Jong-Hyouk; Sakurai, Kouichi; Hori, Yoshiaki

Fast Handover for Hierarchical Mobile IPv6 (F-HMIPv6) that combines advantages of Fast Handover for Mobile IPv6 (FMIPv6) and Hierarchical Mobile IPv6 (HMIPv6) achieves the superior performance in terms of handover latency and signaling overhead compared with previously developed mobility protocols. However, without being secured, F-HMIPv6 is vulnerable to various security threats. In 2007, Kang and Park proposed a security scheme, which is seamlessly integrated into F-HMIPv6. In this paper, we reveal that Kang-Park's scheme cannot defend against the Denial of Service (DoS) and redirect attacks while largely relying on the group key. Then, we propose an Enhanced Security Scheme for F-HMIPv6 (ESS-FH) that achieves the strong key exchange and the key independence as well as addresses the weaknesses of Kang-Park's scheme. More importantly, it enables fast handover between different MAP domains. The proposed scheme is formally verified based on BAN-logic, and its handover latency is analyzed and compared with that of Kang-Park's scheme.

Autoblocker: a system for detecting and blocking of network scanning based on analysis of netflow data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bobyshev, A.; Lamore, D.; Demar, P.

2004-12-01

In a large campus network, such at Fermilab, with tens of thousands of nodes, scanning initiated from either outside of or within the campus network raises security concerns. This scanning may have very serious impact on network performance, and even disrupt normal operation of many services. In this paper we introduce a system for detecting and automatic blocking excessive traffic of different kinds of scanning, DoS attacks, virus infected computers. The system, called AutoBlocker, is a distributed computing system based on quasi-real time analysis of network flow data collected from the border router and core switches. AutoBlocker also has anmore » interface to accept alerts from IDS systems (e.g. BRO, SNORT) that are based on other technologies. The system has multiple configurable alert levels for the detection of anomalous behavior and configurable trigger criteria for automated blocking of scans at the core or border routers. It has been in use at Fermilab for about 2 years, and has become a very valuable tool to curtail scan activity within the Fermilab campus network.« less

A graph-based system for network-vulnerability analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swiler, L.P.; Phillips, C.

1998-06-01

This paper presents a graph-based approach to network vulnerability analysis. The method is flexible, allowing analysis of attacks from both outside and inside the network. It can analyze risks to a specific network asset, or examine the universe of possible consequences following a successful attack. The graph-based tool can identify the set of attack paths that have a high probability of success (or a low effort cost) for the attacker. The system could be used to test the effectiveness of making configuration changes, implementing an intrusion detection system, etc. The analysis system requires as input a database of common attacks,more » broken into atomic steps, specific network configuration and topology information, and an attacker profile. The attack information is matched with the network configuration information and an attacker profile to create a superset attack graph. Nodes identify a stage of attack, for example the class of machines the attacker has accessed and the user privilege level he or she has compromised. The arcs in the attack graph represent attacks or stages of attacks. By assigning probabilities of success on the arcs or costs representing level-of-effort for the attacker, various graph algorithms such as shortest-path algorithms can identify the attack paths with the highest probability of success.« less

Application of Cellular Automata to Detection of Malicious Network Packets

ERIC Educational Resources Information Center

Brown, Robert L.

2014-01-01

A problem in computer security is identification of attack signatures in network packets. An attack signature is a pattern of bits that characterizes a particular attack. Because there are many kinds of attacks, there are potentially many attack signatures. Furthermore, attackers may seek to avoid detection by altering the attack mechanism so that…

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.

Chitosan Mediates Germling Adhesion in Magnaporthe oryzae and Is Required for Surface Sensing and Germling Morphogenesis

PubMed Central

Geoghegan, Ivey A.; Gurr, Sarah J.

2016-01-01

The fungal cell wall not only plays a critical role in maintaining cellular integrity, but also forms the interface between fungi and their environment. The composition of the cell wall can therefore influence the interactions of fungi with their physical and biological environments. Chitin, one of the main polysaccharide components of the wall, can be chemically modified by deacetylation. This reaction is catalyzed by a family of enzymes known as chitin deacetylases (CDAs), and results in the formation of chitosan, a polymer of β1,4-glucosamine. Chitosan has previously been shown to accumulate in the cell wall of infection structures in phytopathogenic fungi. Here, it has long been hypothesized to act as a 'stealth' molecule, necessary for full pathogenesis. In this study, we used the crop pathogen and model organism Magnaporthe oryzae to test this hypothesis. We first confirmed that chitosan localizes to the germ tube and appressorium, then deleted CDA genes on the basis of their elevated transcript levels during appressorium differentiation. Germlings of the deletion strains showed loss of chitin deacetylation, and were compromised in their ability to adhere and form appressoria on artificial hydrophobic surfaces. Surprisingly, the addition of exogenous chitosan fully restored germling adhesion and appressorium development. Despite the lack of appressorium development on artificial surfaces, pathogenicity was unaffected in the mutant strains. Further analyses demonstrated that cuticular waxes are sufficient to over-ride the requirement for chitosan during appressorium development on the plant surface. Thus, chitosan does not have a role as a 'stealth' molecule, but instead mediates the adhesion of germlings to surfaces, thereby allowing the perception of the physical stimuli necessary to promote appressorium development. This study thus reveals a novel role for chitosan in phytopathogenic fungi, and gives further insight into the mechanisms governing appressorium development in M.oryzae. PMID:27315248

Distribution and Correlates of Self-Reported Crimes of Trust

PubMed Central

Menard, Scott; Morris, Robert G.; Gerber, Jurg; Covey, Herbert C.

2012-01-01

This study examines the distribution and correlates of a special class of property crimes, crimes of trust, using longitudinal and cross sectional self-report data from a national sample. We begin by defining crimes of trust and consider their conceptual relationship to “conventional” property crimes, which we here characterize as crimes of stealth, and to white collar crimes, which are defined in terms of the social status of the perpetrators. Crimes of trust are here defined as property crimes that typically involve deliberate contact with the victim or, where there is more than one victim, with at least one or more victims, in which there is typically more of a focus on concealing the fact that a crime has been committed than on concealing the identity of the perpetrator (as is the case in crimes of stealth), without regard to the socioeconomic status of the perpetrator (thus including but not limited to white collar crimes). The focus here is on crimes of trust committed by individuals (as opposed to corporate crime). We first examine their distribution by sociodemographic characteristics, then examine the correlation of crimes of trust with other types of illegal behavior, using data from the National Youth Survey Family Study, including (1) longitudinal self-report data from a nationally representative panel of individuals who were 11–18 years old in 1976–77 and who were followed through early middle age (ages 36–44) in 2002–2003, plus (2) cross-sectional data on these individuals plus their parents, spouses, and children age 11 and older in 2002–2003 (total age range 11–88). The results suggest that crimes of trust have a different age-crime curve from conventional crimes, and that they are not as strongly correlated with problem substance use, gender, and other socioeconomic indicators as conventional crimes. PMID:22347761

Videoexoscopic real-time intraoperative navigation for spinal neurosurgery: a novel co-adaptation of two existing technology platforms, technical note.

PubMed

Huang, Meng; Barber, Sean Michael; Steele, William James; Boghani, Zain; Desai, Viren Rajendrakumar; Britz, Gavin Wayne; West, George Alexander; Trask, Todd Wilson; Holman, Paul Joseph

2018-06-01

Image-guided approaches to spinal instrumentation and interbody fusion have been widely popularized in the last decade [1-5]. Navigated pedicle screws are significantly less likely to breach [2, 3, 5, 6]. Navigation otherwise remains a point reference tool because the projection is off-axis to the surgeon's inline loupe or microscope view. The Synaptive robotic brightmatter drive videoexoscope monitor system represents a new paradigm for off-axis high-definition (HD) surgical visualization. It has many advantages over the traditional microscope and loupes, which have already been demonstrated in a cadaveric study [7]. An auxiliary, but powerful capability of this system is projection of a second, modifiable image in a split-screen configuration. We hypothesized that integration of both Medtronic and Synaptive platforms could permit the visualization of reconstructed navigation and surgical field images simultaneously. By utilizing navigated instruments, this configuration has the ability to support live image-guided surgery or real-time navigation (RTN). Medtronic O-arm/Stealth S7 navigation, MetRx, NavLock, and SureTrak spinal systems were implemented on a prone cadaveric specimen with a stream output to the Synaptive Display. Surgical visualization was provided using a Storz Image S1 platform and camera mounted to the Synaptive robotic brightmatter drive. We were able to successfully technically co-adapt both platforms. A minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and an open pedicle subtraction osteotomy (PSO) were performed using a navigated high-speed drill under RTN. Disc Shaver and Trials under RTN were implemented on the MIS TLIF. The synergy of Synaptive HD videoexoscope robotic drive and Medtronic Stealth platforms allow for live image-guided surgery or real-time navigation (RTN). Off-axis projection also allows upright neutral cervical spine operative ergonomics for the surgeons and improved surgical team visualization and education compared to traditional means. This technique has the potential to augment existing minimally invasive and open approaches, but will require long-term outcome measurements for efficacy.

SU-F-T-582: Small Field Dosimetry in Radiosurgery Collimators with a Stealth Chamber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azcona, J; Barbes, B

2016-06-15

Purpose: The extraction of a reference signal for measuring small fields in scanning mode can be problematic. In this work we describe the use of a transmission chamber in small field dosimetry for radiosurgery collimators and compare TMR curves obtained with stereotactic diode and microionization chamber. Methods: Four radiosurgery cones of diameters 5, 10, 12.5, and 15mm supplied by Elekta Medical were commissioned in a 6MV FFF beam from an Elekta Versa linac. A transmission chamber manufactured by IBA (Stealth chamber) was attached to the lower part of the collimators and used for PDD and profile measurements in scanning modemore » with a Scanditronix stereotactic diode. It was also used for centering the stereotactic diode in the water tank to measure TMR and output factors, by integrating the signal. TMR measurements for all collimators and the OF for the largest collimator were also acquired on a polystyrene PTW 29672 phantom with a PTW PinPoint 3D chamber 0.016 cm3 volume. Results: Measured TMR with diode and microionization chamber agreed very well with differences larger than 1% only for depths above 15cm, except the smaller collimator, for which differences were always smaller than 2%. Calculated TMR were significantly different (up to 7%) from measured TMR. The differences are attributed to the change in response of the diode with depth, because the effective field aperture varies with depth. Furthermore, neglecting the ratio of phantom-scatter factors in the conversion formula also contributes to this difference. OF measured with diode and chamber showed a difference of 3.5%. Conclusion: The transmission chamber overcomes the problem of extracting a reference signal and is of great help for small field commissioning. Calculating TMR from PDD is strongly discouraged. Good agreement was found when comparing measurements of TMR with stereotactic diode in water with measurements with microionization chamber in polystyrene.« less

“Stealth cranioplasty:” A novel endeavor for symptomatic adult Chiari I patients with syringomyelia: Technical note, appraisal, and philosophical considerations

PubMed Central

Rahman, Asifur; Rana, Md. Sumon; Bhandari, Paawan Bahadur; Asif, Dewan Shamsul; Uddin, Abu Naim Wakil; Obaida, Abu Saleh Mohammad Abu; Rahman, Md. Atikur; Alam, Md. Shamsul

2017-01-01

Aim and Objective: In this article, we describe a novel technique of reconstruction of posterior fossa by cranioplasty with use of preshaped titanium mesh following posterior fossa decompression (PFD) for Chiari malformation type I (CMI) with syringomyelia (SM) in symptomatic adults. Materials and Methods: Eleven patients underwent limited PFD and expansive cranioplasty with preshaped titanium mesh, what we term as “Stealth Cranioplasty” (SCP), following arachnoid preserving duraplasty (APD) and hexagonal tenting of the duraplasty with the cranioplasty (HTDC) for the management of symptomatic adult CMI with SM. All these patients had syringes extending from 3 to >10 vertebral levels. Results: Seven male and four female symptomatic CMI adult patients, between age ranges of 22 and 44 years (mean 29.45 years), presented with different neurological symptoms related to CMI and SM for 6–84 months (mean 37.09 months). All the patients underwent PFD, APD followed by SCP and HTDC and were followed up for 7–54 months (mean 35.90 months). Of 11 patients, 8 patients improved according to the Chicago Chiari Outcome Scale (CCOS) with score of 13–15 while 3 patients remained unchanged with CCOS of 12, and there was no worsening. There was no complication related to Chiari surgery in any of the patients. All the patients had good reestablishment of cisterna magna. Two patients had marked reduction of syrinx while eight patients had moderate-to-mild reduction and one patient had no change of syrinx. None of the patients needed redo surgery. Conclusion: SCP is an effective, fruitful, and cost-effective technique for the management of symptomatic adult CMI with SM. This technique has the advantages of preventing complications and recurrences in addition to the improvement of symptoms by addressing the basic pathology. PMID:29021676

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

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…

On Patarin's Attack against the lIC Scheme

NASA Astrophysics Data System (ADS)

Ogura, Naoki; Uchiyama, Shigenori

In 2007, Ding et al. proposed an attractive scheme, which is called the l-Invertible Cycles (lIC) scheme. lIC is one of the most efficient multivariate public-key cryptosystems (MPKC); these schemes would be suitable for using under limited computational resources. In 2008, an efficient attack against lIC using Gröbner basis algorithms was proposed by Fouque et al. However, they only estimated the complexity of their attack based on their experimental results. On the other hand, Patarin had proposed an efficient attack against some multivariate public-key cryptosystems. We call this attack Patarin's attack. The complexity of Patarin's attack can be estimated by finding relations corresponding to each scheme. In this paper, we propose an another practical attack against the lIC encryption/signature scheme. We estimate the complexity of our attack (not experimentally) by adapting Patarin's attack. The attack can be also applied to the lIC- scheme. Moreover, we show some experimental results of a practical attack against the lIC/lIC- schemes. This is the first implementation of both our proposed attack and an attack based on Gröbner basis algorithm for the even case, that is, a parameter l is even.

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.

Split-second escape decisions in blue tits (Parus caeruleus)

NASA Astrophysics Data System (ADS)

Lind, Johan; Kaby, Ulrika; Jakobsson, Sven

2002-07-01

Bird mortality is heavily affected by birds of prey. Under attack, take-off is crucial for survival and even minor mistakes in initial escape response can have devastating consequences. Birds may respond differently depending on the character of the predator's attack and these split-second decisions were studied using a model merlin (Falco columbarius) that attacked feeding blue tits (Parus caeruleus) from two different attack angles in two different speeds. When attacked from a low attack angle they took off more steeply than when attacked from a high angle. This is the first study to show that escape behaviour also depends on predator attack speed. The blue tits responded to a high-speed attack by dodging sideways more often than when attacked at a low speed. Escape speed was not significantly affected by the different treatments. Although they have only a split-second before escaping an attack, blue tits do adjust their escape strategy to the prevailing attack conditions.

Hybrid attacks on model-based social recommender systems

NASA Astrophysics Data System (ADS)

Yu, Junliang; Gao, Min; Rong, Wenge; Li, Wentao; Xiong, Qingyu; Wen, Junhao

2017-10-01

With the growing popularity of the online social platform, the social network based approaches to recommendation emerged. However, because of the open nature of rating systems and social networks, the social recommender systems are susceptible to malicious attacks. In this paper, we present a certain novel attack, which inherits characteristics of the rating attack and the relation attack, and term it hybrid attack. Furtherly, we explore the impact of the hybrid attack on model-based social recommender systems in multiple aspects. The experimental results show that, the hybrid attack is more destructive than the rating attack in most cases. In addition, users and items with fewer ratings will be influenced more when attacked. Last but not the least, the findings suggest that spammers do not depend on the feedback links from normal users to become more powerful, the unilateral links can make the hybrid attack effective enough. Since unilateral links are much cheaper, the hybrid attack will be a great threat to model-based social recommender systems.

Detecting Pulsing Denial-of-Service Attacks with Nondeterministic Attack Intervals

NASA Astrophysics Data System (ADS)

Luo, Xiapu; Chan, Edmond W. W.; Chang, Rocky K. C.

2009-12-01

This paper addresses the important problem of detecting pulsing denial of service (PDoS) attacks which send a sequence of attack pulses to reduce TCP throughput. Unlike previous works which focused on a restricted form of attacks, we consider a very broad class of attacks. In particular, our attack model admits any attack interval between two adjacent pulses, whether deterministic or not. It also includes the traditional flooding-based attacks as a limiting case (i.e., zero attack interval). Our main contribution is Vanguard, a new anomaly-based detection scheme for this class of PDoS attacks. The Vanguard detection is based on three traffic anomalies induced by the attacks, and it detects them using a CUSUM algorithm. We have prototyped Vanguard and evaluated it on a testbed. The experiment results show that Vanguard is more effective than the previous methods that are based on other traffic anomalies (after a transformation using wavelet transform, Fourier transform, and autocorrelation) and detection algorithms (e.g., dynamic time warping).

Cyber-Physical Attacks With Control Objectives

DOE PAGES

Chen, Yuan; Kar, Soummya; Moura, Jose M. F.

2017-08-18

This study studies attackers with control objectives against cyber-physical systems (CPSs). The goal of the attacker is to counteract the CPS's controller and move the system to a target state while evading detection. We formulate a cost function that reflects the attacker's goals, and, using dynamic programming, we show that the optimal attack strategy reduces to a linear feedback of the attacker's state estimate. By changing the parameters of the cost function, we show how an attacker can design optimal attacks to balance the control objective and the detection avoidance objective. In conclusion, we provide a numerical illustration based onmore » a remotely controlled helicopter under attack.« less

Cyber-Physical Attacks With Control Objectives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yuan; Kar, Soummya; Moura, Jose M. F.

This study studies attackers with control objectives against cyber-physical systems (CPSs). The goal of the attacker is to counteract the CPS's controller and move the system to a target state while evading detection. We formulate a cost function that reflects the attacker's goals, and, using dynamic programming, we show that the optimal attack strategy reduces to a linear feedback of the attacker's state estimate. By changing the parameters of the cost function, we show how an attacker can design optimal attacks to balance the control objective and the detection avoidance objective. In conclusion, we provide a numerical illustration based onmore » a remotely controlled helicopter under attack.« less

Epigenetics and epidemiology: models of study and examples.

PubMed

van Veldhoven, Karin; Rahman, Shati; Vineis, Paolo

2014-01-01

Epidemiological studies have successfully identified several environmental causes of disease, but often these studies are limited by methodological problems (e.g. lack of sensitivity and specificity in exposure assessment; confounding). Proposed approaches to improve observational studies of environmental associations are Mendelian randomization and the meet-in-the-middle (MITM) approach. The latter uses signals from the growing field of -omics as putative intermediate biomarkers in the pathogenetic process that links exposure with disease. The first part of this approach consists in the association between exposure and disease. The next step consists in the study of the relationship between (biomarkers of) exposure and intermediate -omic biomarkers of early effect; thirdly, the relation between the disease outcome and intermediate -omic biomarkers is assessed. We propose that when an association is found in all three steps it is possible that there is a casual association. One of the associations that have been investigated extensively in the recent years but is not completely understood is that between environmental endocrine disruptors and breast cancer. Here we present an example of how the "meet-in-the-middle" approach can be used to address the role of endocrine disruptors, by reviewing the relevant literature.

Performance Improvement of Power Analysis Attacks on AES with Encryption-Related Signals

NASA Astrophysics Data System (ADS)

Lee, You-Seok; Lee, Young-Jun; Han, Dong-Guk; Kim, Ho-Won; Kim, Hyoung-Nam

A power analysis attack is a well-known side-channel attack but the efficiency of the attack is frequently degraded by the existence of power components, irrelative to the encryption included in signals used for the attack. To enhance the performance of the power analysis attack, we propose a preprocessing method based on extracting encryption-related parts from the measured power signals. Experimental results show that the attacks with the preprocessed signals detect correct keys with much fewer signals, compared to the conventional power analysis attacks.

Attacks on public telephone networks: technologies and challenges

NASA Astrophysics Data System (ADS)

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

2003-09-01

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

Fast WEP-Key Recovery Attack Using Only Encrypted IP Packets

NASA Astrophysics Data System (ADS)

Teramura, Ryoichi; Asakura, Yasuo; Ohigashi, Toshihiro; Kuwakado, Hidenori; Morii, Masakatu

Conventional efficient key recovery attacks against Wired Equivalent Privacy (WEP) require specific initialization vectors or specific packets. Since it takes much time to collect the packets sufficiently, any active attack should be performed. An Intrusion Detection System (IDS), however, will be able to prevent the attack. Since the attack logs are stored at the servers, it is possible to prevent such an attack. This paper proposes an algorithm for recovering a 104-bit WEP key from any IP packets in a realistic environment. This attack needs about 36, 500 packets with a success probability 0.5, and the complexity of our attack is equivalent to about 220 computations of the RC4 key setups. Since our attack is passive, it is difficult for both WEP users and administrators to detect our attack.

[INVITED] Coherent perfect absorption of electromagnetic wave in subwavelength structures

NASA Astrophysics Data System (ADS)

Yan, Chao; Pu, Mingbo; Luo, Jun; Huang, Yijia; Li, Xiong; Ma, Xiaoliang; Luo, Xiangang

2018-05-01

Electromagnetic (EM) absorption is a common process by which the EM energy is transformed into other kinds of energy in the absorber, for example heat. Perfect absorption of EM with structures at subwavelength scale is important for many practical applications, such as stealth technology, thermal control and sensing. Coherent perfect absorption arises from the interplay of interference and absorption, which can be interpreted as a time-reversed process of lasing or EM emitting. It provides a promising way for complete absorption in both nanophotonics and electromagnetics. In this review, we discuss basic principles and properties of a coherent perfect absorber (CPA). Various subwavelength structures including thin films, metamaterials and waveguide-based structures to realize CPAs are compared. We also discuss the potential applications of CPAs.

Passive synthetic aperture radar imaging of ground moving targets

NASA Astrophysics Data System (ADS)

Wacks, Steven; Yazici, Birsen

2012-05-01

In this paper we present a method for imaging ground moving targets using passive synthetic aperture radar. A passive radar imaging system uses small, mobile receivers that do not radiate any energy. For these reasons, passive imaging systems result in signicant cost, manufacturing, and stealth advantages. The received signals are obtained by multiple airborne receivers collecting scattered waves due to illuminating sources of opportunity such as commercial television, radio, and cell phone towers. We describe a novel forward model and a corresponding ltered-backprojection type image reconstruction method combined with entropy optimization. Our method determines the location and velocity of multiple targets moving at dierent velocities. Furthermore, it can accommodate arbitrary imaging geometries. we present numerical simulations to verify the imaging method.

Impedance matched thin metamaterials make metals absorbing.

PubMed

Mattiucci, N; Bloemer, M J; Aközbek, N; D'Aguanno, G

2013-11-13

Metals are generally considered good reflectors over the entire electromagnetic spectrum up to their plasma frequency. Here we demonstrate an approach to tailor their absorbing characteristics based on the effective metamaterial properties of thin, periodic metallo-dielectric multilayers by exploiting a broadband, inherently non-resonant, surface impedance matching mechanism. Based on this mechanism, we design, fabricate and test omnidirectional, thin (<1 micron), polarization independent, extremely efficient absorbers (in principle being capable to reach A > 99%) over a frequency range spanning from the UV to the IR. Our approach opens new venues to design cost effective materials for many applications such as thermo-photovoltaic energy conversion devices, light harvesting for solar cells, flat panel display, infrared detectors, stray light reduction, stealth and others.

Enhanced Broadband Electromagnetic Absorption in Silicon Film with Photonic Crystal Surface and Random Gold Grooves Reflector

PubMed Central

Chen, Zhi-Hui; Qiao, Na; Yang, Yibiao; Ye, Han; Liu, Shaoding; Wang, Wenjie; Wang, Yuncai

2015-01-01

We show a hybrid structure consisting of Si film with photonic crystal surface and random triangular gold grooves reflector at the bottom, which is capable of realizing efficient, broad-band, wide-angle optical absorption. It is numerically demonstrated that the enhanced absorption in a broad wavelength range (0.3–9.9 μm) due to the scattering effect of both sides of the structure and the created resonance modes. Larger thickness and period are favored to enhance the absorption in broader wavelength range. Substantial electric field concentrates in the grooves of surface photonic crystal and in the Si film. Our structure is versatile for solar cells, broadband photodetection and stealth coating. PMID:26238270

A Statistical Analysis of Corona Topography: New Insights into Corona Formation and Evolution

NASA Technical Reports Server (NTRS)

Stofan, E. R.; Glaze, L. S.; Smrekar, S. E.; Baloga, S. M.

2003-01-01

Extensive mapping of the surface of Venus and continued analysis of Magellan data have allowed a more comprehensive survey of coronae to be conducted. Our updated corona database contains 514 features, an increase from the 326 coronae of the previous survey. We include a new set of 106 Type 2 or stealth coronae, which have a topographic rather than a fracture annulus. The large increase in the number of coronae over the 1992 survey results from several factors, including the use of the full Magellan data set and the addition of features identified as part of the systematic geologic mapping of Venus. Parameters of the population that we have analyzed to date include size and topography.

Explicit solution techniques for impact with contact constraints

NASA Technical Reports Server (NTRS)

Mccarty, Robert E.

1993-01-01

Modern military aircraft transparency systems, windshields and canopies, are complex systems which must meet a large and rapidly growing number of requirements. Many of these transparency system requirements are conflicting, presenting difficult balances which must be achieved. One example of a challenging requirements balance or trade is shaping for stealth versus aircrew vision. The large number of requirements involved may be grouped in a variety of areas including man-machine interface; structural integration with the airframe; combat hazards; environmental exposures; and supportability. Some individual requirements by themselves pose very difficult, severely nonlinear analysis problems. One such complex problem is that associated with the dynamic structural response resulting from high energy bird impact. An improved analytical capability for soft-body impact simulation was developed.

Explicit solution techniques for impact with contact constraints

NASA Astrophysics Data System (ADS)

McCarty, Robert E.

1993-08-01

Modern military aircraft transparency systems, windshields and canopies, are complex systems which must meet a large and rapidly growing number of requirements. Many of these transparency system requirements are conflicting, presenting difficult balances which must be achieved. One example of a challenging requirements balance or trade is shaping for stealth versus aircrew vision. The large number of requirements involved may be grouped in a variety of areas including man-machine interface; structural integration with the airframe; combat hazards; environmental exposures; and supportability. Some individual requirements by themselves pose very difficult, severely nonlinear analysis problems. One such complex problem is that associated with the dynamic structural response resulting from high energy bird impact. An improved analytical capability for soft-body impact simulation was developed.

An ultralight and thin metasurface for radar-infrared bi-stealth applications

NASA Astrophysics Data System (ADS)

Zhang, C.; Yang, J.; Yuan, W.; Zhao, J.; Dai, J. Y.; Guo, T. C.; Liang, J.; Xu, G. Y.; Cheng, Q.; Cui, T. J.

2017-11-01

We present a thin metasurface with large microwave absorptivity and low infrared emissivity simultaneously. By properly tuning the resonance peaks and impedance of the meta-atom, broadband microwave absorptivity greater than 90% from 8.2 to 16.0 GHz is achieved. In the meantime, owing to large coverage of periodic metal patches on the top surface, low infrared emissivity is exhibited in the infrared region (IR) of 8 µm-14 µm. The excellent agreement between numerical simulation and experimental result demonstrates the good performance of the proposed metasurface. Due to the usage of polymethacrylimide (PMI) and polyethylene terephthalate (PET) as the substrate, the metasurface is especially advantageous for the light weight, making it a favorite in real engineering applications.

Robustness of coevolution in resolving prisoner's dilemma games on interdependent networks subject to attack

NASA Astrophysics Data System (ADS)

Liu, Penghui; Liu, Jing

2017-08-01

Recently, coevolution between strategy and network structure has been established as a rule to resolve social dilemmas and reach optimal situations for cooperation. Many follow-up researches have focused on studying how coevolution helps networks reorganize to deter the defectors and many coevolution methods have been proposed. However, the robustness of the coevolution rules against attacks have not been studied much. Since attacks may directly influence the original evolutionary process of cooperation, the robustness should be an important index while evaluating the quality of a coevolution method. In this paper, we focus on investigating the robustness of an elementary coevolution method in resolving the prisoner's dilemma game upon the interdependent networks. Three different types of time-independent attacks, named as edge attacks, instigation attacks and node attacks have been employed to test its robustness. Through analyzing the simulation results obtained, we find this coevolution method is relatively robust against the edge attack and the node attack as it successfully maintains cooperation in the population over the entire attack range. However, when the instigation probability of the attacked individuals is large or the attack range of instigation attack is wide enough, coevolutionary rule finally fails in maintaining cooperation in the population.

Security under Uncertainty: Adaptive Attackers Are More Challenging to Human Defenders than Random Attackers

PubMed Central

Moisan, Frédéric; Gonzalez, Cleotilde

2017-01-01

Game Theory is a common approach used to understand attacker and defender motives, strategies, and allocation of limited security resources. For example, many defense algorithms are based on game-theoretic solutions that conclude that randomization of defense actions assures unpredictability, creating difficulties for a human attacker. However, many game-theoretic solutions often rely on idealized assumptions of decision making that underplay the role of human cognition and information uncertainty. The consequence is that we know little about how effective these algorithms are against human players. Using a simplified security game, we study the type of attack strategy and the uncertainty about an attacker's strategy in a laboratory experiment where participants play the role of defenders against a simulated attacker. Our goal is to compare a human defender's behavior in three levels of uncertainty (Information Level: Certain, Risky, Uncertain) and three types of attacker's strategy (Attacker's strategy: Minimax, Random, Adaptive) in a between-subjects experimental design. Best defense performance is achieved when defenders play against a minimax and a random attack strategy compared to an adaptive strategy. Furthermore, when payoffs are certain, defenders are as efficient against random attack strategy as they are against an adaptive strategy, but when payoffs are uncertain, defenders have most difficulties defending against an adaptive attacker compared to a random attacker. We conclude that given conditions of uncertainty in many security problems, defense algorithms would be more efficient if they are adaptive to the attacker actions, taking advantage of the attacker's human inefficiencies. PMID:28690557

Numerical simulation of the optimal two-mode attacks for two-way continuous-variable quantum cryptography in reverse reconciliation

NASA Astrophysics Data System (ADS)

Zhang, Yichen; Li, Zhengyu; Zhao, Yijia; Yu, Song; Guo, Hong

2017-02-01

We analyze the security of the two-way continuous-variable quantum key distribution protocol in reverse reconciliation against general two-mode attacks, which represent all accessible attacks at fixed channel parameters. Rather than against one specific attack model, the expression of secret key rates of the two-way protocol are derived against all accessible attack models. It is found that there is an optimal two-mode attack to minimize the performance of the protocol in terms of both secret key rates and maximal transmission distances. We identify the optimal two-mode attack, give the specific attack model of the optimal two-mode attack and show the performance of the two-way protocol against the optimal two-mode attack. Even under the optimal two-mode attack, the performances of two-way protocol are still better than the corresponding one-way protocol, which shows the advantage of making double use of the quantum channel and the potential of long-distance secure communication using a two-way protocol.

Blind Data Attack on BGP Routers

DTIC Science & Technology

2017-03-01

implement blind attack protection, leaving long -standing connections, such as Border Gateway Protocol (BGP) sessions, vulnerable to exploitation. This...protection measures should a discovered vulnerability reduce attack complexity. 14. SUBJECT TERMS BGP, TCP, blind attack, blind data attack 15. NUMBER OF...implementations may not properly implement blind attack protection, leaving long -standing connections, such as BorderGateway Protocol (BGP) sessions

Research on high power intra-channel crosstalk attack in optical networks

NASA Astrophysics Data System (ADS)

Ren, Shuai; Zhang, Yinfa; Wang, Jingyu; Zhang, Jumei; Rao, Xuejun; Fang, Yuanyuan

2017-02-01

The mechanism of high power intra-channel crosstalk attack is analyzed theoretically and the conclusion that power of attack signal and crosstalk coefficient of optical switch are the main factors for which high power intra-channel have destructive effect on quality of legitimate signals is drawn. Effects of high power intra-channel crosstalk attack on quality of legitimate signals and its capability of attack propagation are investigated quantitatively by building the simulation system in VPI software. The results show that legitimate signals through the first and the second stage optical switch are affected by attack and legitimate signal through the third stage optical switch is almost unaffected by attack when power of original attack signal (OAS) is above 20dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB at optical cross connect 1 (OXC1). High power intra-channel crosstalk attack has a certain capability of attack propagation. Attack capability of OAS can be propagated to OXC3 when power of OAS is 27dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB. We also find that the secondary attack signal (SAS) does not have capability of attack propagation.

Warning Signs of Heart Attack, Stroke and Cardiac Arrest

MedlinePlus

... a Heart Attack WARNING SIGNS OF HEART ATTACK, STROKE & CARDIAC ARREST HEART ATTACK WARNING SIGNS CHEST DISCOMFORT ... nausea or lightheadedness. Learn more about heart attack STROKE WARNING SIGNS Spot a stroke F.A.S.T.: - ...

The role of mental disorder in attacks on European politicians 1990-2004.

PubMed

James, D V; Mullen, P E; Meloy, J R; Pathé, M T; Farnham, F R; Preston, L; Darnley, B

2007-11-01

The only systematic studies of attacks on public figures come from the USA. These studies de-emphasize the role of mental illness and suggest threats are of no predictive value. This study re-examines these questions through a study of attacks on European politicians. All non-terrorist attacks on elected politicians in Western Europe between 1990 and 2004 were analysed. Twenty-four attacks were identified, including five involving fatalities, and eight serious injuries. Ten attackers were psychotic, four drunk, nine politically motivated and one unclassifiable. Eleven attackers evidenced warning behaviours. The mentally disordered, most of whom gave warnings, were responsible for most of the fatal and seriously injurious attacks. A greater awareness of the link between delusional fixations on public figures and subsequent attacks could aid prevention. Equally importantly, recognition would encourage earlier intervention in people who, irrespective of whether they eventually attack, have delusional preoccupations which ruin their lives.

An Exploration of Hypotheses that Explain Herbivore and Pathogen Attack in Restored Plant Communities

PubMed Central

Blaisdell, G. Kai; Roy, Bitty A.; Pfeifer-Meister, Laurel; Bridgham, Scott D.

2015-01-01

Many hypotheses address the associations of plant community composition with natural enemies, including: (i) plant species diversity may reduce enemy attack, (ii) attack may increase as host abundance increases, (iii) enemy spillover may lead to increased attack on one host species due to transmission from another host species, or enemy dilution may lead to reduced attack on a host that would otherwise have more attack, (iv) physical characteristics of the plant community may influence attack, and (v) plant vigor may affect attack. Restoration experiments with replicated plant communities provide an exceptional opportunity to explore these hypotheses. To explore the relative predictive strengths of these related hypotheses and to investigate the potential effect of several restoration site preparation techniques, we surveyed arthropod herbivore and fungal pathogen attack on the six most common native plant species in a restoration experiment. Multi-model inference revealed a weak but consistent negative correlation with pathogen attack and host diversity across the plant community, and no correlation between herbivory and host diversity. Our analyses also revealed host species-specific relationships between attack and abundance of the target host species, other native plant species, introduced plant species, and physical community characteristics. We found no relationship between enemy attack and plant vigor. We found minimal differences in plant community composition among several diverse site preparation techniques, and limited effects of site preparation techniques on attack. The strongest associations of community characteristics with attack varied among plant species with no community-wide patterns, suggesting that no single hypothesis successfully predicts the dominant community-wide trends in enemy attack. PMID:25699672

Cyber attack analysis on cyber-physical systems: Detectability, severity, and attenuation strategy

NASA Astrophysics Data System (ADS)

Kwon, Cheolhyeon

Security of Cyber-Physical Systems (CPS) against malicious cyber attacks is an important yet challenging problem. Since most cyber attacks happen in erratic ways, it is usually intractable to describe and diagnose them systematically. Motivated by such difficulties, this thesis presents a set of theories and algorithms for a cyber-secure architecture of the CPS within the control theoretic perspective. Here, instead of identifying a specific cyber attack model, we are focused on analyzing the system's response during cyber attacks. Firstly, we investigate the detectability of the cyber attacks from the system's behavior under cyber attacks. Specifically, we conduct a study on the vulnerabilities in the CPS's monitoring system against the stealthy cyber attack that is carefully designed to avoid being detected by its detection scheme. After classifying three kinds of cyber attacks according to the attacker's ability to compromise the system, we derive the necessary and sufficient conditions under which such stealthy cyber attacks can be designed to cause the unbounded estimation error while not being detected. Then, the analytical design method of the optimal stealthy cyber attack that maximizes the estimation error is developed. The proposed stealthy cyber attack analysis is demonstrated with illustrative examples on Air Traffic Control (ATC) system and Unmanned Aerial Vehicle (UAV) navigation system applications. Secondly, in an attempt to study the CPSs' vulnerabilities in more detail, we further discuss a methodology to identify potential cyber threats inherent in the given CPSs and quantify the attack severity accordingly. We then develop an analytical algorithm to test the behavior of the CPS under various cyber attack combinations. Compared to a numerical approach, the analytical algorithm enables the prediction of the most effective cyber attack combinations without computing the severity of all possible attack combinations, thereby greatly reducing the computational cost. The proposed algorithm is validated through a linearized longitudinal motion of a UAV example. Finally, we propose an attack attenuation strategy via the controller design for CPSs that are robust to various types of cyber attacks. While the previous studies have investigated a secure control by assuming a specific attack strategy, in this research we propose a hybrid robust control scheme that contains multiple sub-controllers, each matched to a specific type of cyber attacks. Then the system can be adapted to various cyber attacks (including those that are not assumed for sub-controller design) by switching its sub-controllers to achieve the best performance. Then, a method for designing a secure switching logic to counter all possible cyber attacks is proposed and it verifies mathematically the system's performance and stability as well. The performance of the proposed control scheme is demonstrated by an example with the hybrid H2 - H-infinity controller applied to a UAV example.

Method for Integrated Simulation (MINTSIM)

DTIC Science & Technology

1976-01-01

sorties allocated to attack SAMs. FAPA = fraction of striking aircraft attacking air bases which attack parked aircraft in the open. TAAB...each striking aircraft. FAS = fraction of striking aircraft attacking air bases which attack sheltered aircraft. (NOTE: FAPA + FAS = 1.0

Finite Energy and Bounded Actuator Attacks on Cyber-Physical Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djouadi, Seddik M; Melin, Alexander M; Ferragut, Erik M

As control system networks are being connected to enterprise level networks for remote monitoring, operation, and system-wide performance optimization, these same connections are providing vulnerabilities that can be exploited by malicious actors for attack, financial gain, and theft of intellectual property. Much effort in cyber-physical system (CPS) protection has focused on protecting the borders of the system through traditional information security techniques. Less effort has been applied to the protection of cyber-physical systems from intelligent attacks launched after an attacker has defeated the information security protections to gain access to the control system. In this paper, attacks on actuator signalsmore » are analyzed from a system theoretic context. The threat surface is classified into finite energy and bounded attacks. These two broad classes encompass a large range of potential attacks. The effect of theses attacks on a linear quadratic (LQ) control are analyzed, and the optimal actuator attacks for both finite and infinite horizon LQ control are derived, therefore the worst case attack signals are obtained. The closed-loop system under the optimal attack signals is given and a numerical example illustrating the effect of an optimal bounded attack is provided.« less

Web Forms and Untraceable DDoS Attacks

NASA Astrophysics Data System (ADS)

Jakobsson, Markus; Menczer, Filippo

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

Replacement Attack: A New Zero Text Watermarking Attack

NASA Astrophysics Data System (ADS)

Bashardoost, Morteza; Mohd Rahim, Mohd Shafry; Saba, Tanzila; Rehman, Amjad

2017-03-01

The main objective of zero watermarking methods that are suggested for the authentication of textual properties is to increase the fragility of produced watermarks against tampering attacks. On the other hand, zero watermarking attacks intend to alter the contents of document without changing the watermark. In this paper, the Replacement attack is proposed, which focuses on maintaining the location of the words in the document. The proposed text watermarking attack is specifically effective on watermarking approaches that exploit words' transition in the document. The evaluation outcomes prove that tested word-based method are unable to detect the existence of replacement attack in the document. Moreover, the comparison results show that the size of Replacement attack is estimated less accurate than other common types of zero text watermarking attacks.

Design and Analysis of an Enhanced Patient-Server Mutual Authentication Protocol for Telecare Medical Information System.

PubMed

Amin, Ruhul; Islam, S K Hafizul; Biswas, G P; Khan, Muhammad Khurram; Obaidat, Mohammad S

2015-11-01

In order to access remote medical server, generally the patients utilize smart card to login to the server. It has been observed that most of the user (patient) authentication protocols suffer from smart card stolen attack that means the attacker can mount several common attacks after extracting smart card information. Recently, Lu et al.'s proposes a session key agreement protocol between the patient and remote medical server and claims that the same protocol is secure against relevant security attacks. However, this paper presents several security attacks on Lu et al.'s protocol such as identity trace attack, new smart card issue attack, patient impersonation attack and medical server impersonation attack. In order to fix the mentioned security pitfalls including smart card stolen attack, this paper proposes an efficient remote mutual authentication protocol using smart card. We have then simulated the proposed protocol using widely-accepted AVISPA simulation tool whose results make certain that the same protocol is secure against active and passive attacks including replay and man-in-the-middle attacks. Moreover, the rigorous security analysis proves that the proposed protocol provides strong security protection on the relevant security attacks including smart card stolen attack. We compare the proposed scheme with several related schemes in terms of computation cost and communication cost as well as security functionalities. It has been observed that the proposed scheme is comparatively better than related existing schemes.

Simulation of Attacks for Security in Wireless Sensor Network.

PubMed

Diaz, Alvaro; Sanchez, Pablo

2016-11-18

The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN) require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node's software execution time and power consumption estimation). After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work.

Heartburn or Chest Pain: When Is It Heart Attack?

MedlinePlus

Heartburn or heart attack: When to worry Severe heartburn and heart attack can be hard to tell apart. Understand how they typically ... flow to your heart (angina) or an actual heart attack. Heartburn, angina and heart attack may feel very ...

Know the Warning Signs of a Heart Attack

MedlinePlus

... No. 22 Know the Warning Signs of a Heart Attack What is a heart attack? Aheart attack happens when the blood vessels that ... hurting your heart muscle. Another name for a heart attack is myocardial infarction, or MI. If you have ...

Percolation of localized attack on isolated and interdependent random networks

NASA Astrophysics Data System (ADS)

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

2014-03-01

Percolation properties of isolated and interdependent random networks have been investigated extensively. The focus of these studies has been on random attacks where each node in network is attacked with the same probability or targeted attack where each node is attacked with a probability being a function of its centrality, such as degree. Here we discuss a new type of realistic attacks which we call a localized attack where a group of neighboring nodes in the networks are attacked. We attack a randomly chosen node, its neighbors, and its neighbor of neighbors and so on, until removing a fraction (1 - p) of the network. This type of attack reflects damages due to localized disasters, such as earthquakes, floods and war zones in real-world networks. We study, both analytically and by simulations the impact of localized attack on percolation properties of random networks with arbitrary degree distributions and discuss in detail random regular (RR) networks, Erdős-Rényi (ER) networks and scale-free (SF) networks. We extend and generalize our theoretical and simulation results of single isolated networks to networks formed of interdependent networks.

Stealthy false data injection attacks using matrix recovery and independent component analysis in smart grid

NASA Astrophysics Data System (ADS)

JiWei, Tian; BuHong, Wang; FuTe, Shang; Shuaiqi, Liu

2017-05-01

Exact state estimation is vital important to maintain common operations of smart grids. Existing researches demonstrate that state estimation output could be compromised by malicious attacks. However, to construct the attack vectors, a usual presumption in most works is that the attacker has perfect information regarding the topology and so on even such information is difficult to acquire in practice. Recent research shows that Independent Component Analysis (ICA) can be used for inferring topology information which can be used to originate undetectable attacks and even to alter the price of electricity for the profits of attackers. However, we found that the above ICA-based blind attack tactics is merely feasible in the environment with Gaussian noises. If there are outliers (device malfunction and communication errors), the Bad Data Detector will easily detect the attack. Hence, we propose a robust ICA based blind attack strategy that one can use matrix recovery to circumvent the outlier problem and construct stealthy attack vectors. The proposed attack strategies are tested with IEEE representative 14-bus system. Simulations verify the feasibility of the proposed method.

Shilling Attacks Detection in Recommender Systems Based on Target Item Analysis

PubMed Central

Zhou, Wei; Wen, Junhao; Koh, Yun Sing; Xiong, Qingyu; Gao, Min; Dobbie, Gillian; Alam, Shafiq

2015-01-01

Recommender systems are highly vulnerable to shilling attacks, both by individuals and groups. Attackers who introduce biased ratings in order to affect recommendations, have been shown to negatively affect collaborative filtering (CF) algorithms. Previous research focuses only on the differences between genuine profiles and attack profiles, ignoring the group characteristics in attack profiles. In this paper, we study the use of statistical metrics to detect rating patterns of attackers and group characteristics in attack profiles. Another question is that most existing detecting methods are model specific. Two metrics, Rating Deviation from Mean Agreement (RDMA) and Degree of Similarity with Top Neighbors (DegSim), are used for analyzing rating patterns between malicious profiles and genuine profiles in attack models. Building upon this, we also propose and evaluate a detection structure called RD-TIA for detecting shilling attacks in recommender systems using a statistical approach. In order to detect more complicated attack models, we propose a novel metric called DegSim’ based on DegSim. The experimental results show that our detection model based on target item analysis is an effective approach for detecting shilling attacks. PMID:26222882

TANDI: threat assessment of network data and information

NASA Astrophysics Data System (ADS)

Holsopple, Jared; Yang, Shanchieh Jay; Sudit, Moises

2006-04-01

Current practice for combating cyber attacks typically use Intrusion Detection Sensors (IDSs) to passively detect and block multi-stage attacks. This work leverages Level-2 fusion that correlates IDS alerts belonging to the same attacker, and proposes a threat assessment algorithm to predict potential future attacker actions. The algorithm, TANDI, reduces the problem complexity by separating the models of the attacker's capability and opportunity, and fuse the two to determine the attacker's intent. Unlike traditional Bayesian-based approaches, which require assigning a large number of edge probabilities, the proposed Level-3 fusion procedure uses only 4 parameters. TANDI has been implemented and tested with randomly created attack sequences. The results demonstrate that TANDI predicts future attack actions accurately as long as the attack is not part of a coordinated attack and contains no insider threats. In the presence of abnormal attack events, TANDI will alarm the network analyst for further analysis. The attempt to evaluate a threat assessment algorithm via simulation is the first in the literature, and shall open up a new avenue in the area of high level fusion.

Identifying and tracking attacks on networks: C3I displays and related technologies

NASA Astrophysics Data System (ADS)

Manes, Gavin W.; Dawkins, J.; Shenoi, Sujeet; Hale, John C.

2003-09-01

Converged network security is extremely challenging for several reasons; expanded system and technology perimeters, unexpected feature interaction, and complex interfaces all conspire to provide hackers with greater opportunities for compromising large networks. Preventive security services and architectures are essential, but in and of themselves do not eliminate all threat of compromise. Attack management systems mitigate this residual risk by facilitating incident detection, analysis and response. There are a wealth of attack detection and response tools for IP networks, but a dearth of such tools for wireless and public telephone networks. Moreover, methodologies and formalisms have yet to be identified that can yield a common model for vulnerabilities and attacks in converged networks. A comprehensive attack management system must coordinate detection tools for converged networks, derive fully-integrated attack and network models, perform vulnerability and multi-stage attack analysis, support large-scale attack visualization, and orchestrate strategic responses to cyber attacks that cross network boundaries. We present an architecture that embodies these principles for attack management. The attack management system described engages a suite of detection tools for various networking domains, feeding real-time attack data to a comprehensive modeling, analysis and visualization subsystem. The resulting early warning system not only provides network administrators with a heads-up cockpit display of their entire network, it also supports guided response and predictive capabilities for multi-stage attacks in converged networks.

Pre-attack signs and symptoms in cluster headache: Characteristics and time profile.

PubMed

Snoer, Agneta; Lund, Nunu; Beske, Rasmus; Jensen, Rigmor; Barloese, Mads

2018-05-01

Introduction In contrast to the premonitory phase of migraine, little is known about the pre-attack (prodromal) phase of a cluster headache. We aimed to describe the nature, prevalence, and duration of pre-attack symptoms in cluster headache. Methods Eighty patients with episodic cluster headache or chronic cluster headache, according to ICHD-3 beta criteria, were invited to participate. In this observational study, patients underwent a semi-structured interview where they were asked about the presence of 31 symptoms/signs in relation to a typical cluster headache attack. Symptoms included previously reported cluster headache pre-attack symptoms, premonitory migraine symptoms and accompanying symptoms of migraine and cluster headache. Results Pre-attack symptoms were reported by 83.3% of patients, with an average of 4.25 (SD 3.9) per patient. Local and painful symptoms, occurring with a median of 10 minutes before attack, were reported by 70%. Local and painless symptoms and signs, occurring with a median of 10 minutes before attack, were reported by 43.8% and general symptoms, occurring with a median of 20 minutes before attack, were reported by 62.5% of patients. Apart from a dull/aching sensation in the attack area being significantly ( p < 0.05) more frequent among men and episodic patients, compared with women and chronic patients respectively, no other differences in the prevalence of pre-attack symptoms were identified between groups. Conclusion Pre-attack symptoms are frequent in cluster headache. Since the origin of cluster headache attacks is still unresolved, studies of pre-attack symptoms could contribute to the understanding of cluster headache pathophysiology. Furthermore, identification and recognition of pre-attack symptoms could potentially allow earlier abortive treatment.

Shark attack-related injuries: Epidemiology and implications for plastic surgeons.

PubMed

Ricci, Joseph A; Vargas, Christina R; Singhal, Dhruv; Lee, Bernard T

2016-01-01

The increased media attention to shark attacks has led to a heightened fear and public awareness. Although few sharks are considered dangerous, attacks on humans can result in large soft tissue defects necessitating the intervention of reconstructive surgeons. This study aims to evaluate and describe the characteristics of shark-related injuries in order to improve treatment. The Global Shark Accident File, maintained by the Shark Research Institute (Princeton, NJ, USA), is a compilation of all known worldwide shark attacks. Database records since the 1900s were reviewed to identify differences between fatal and nonfatal attacks, including: geography, injury pattern, shark species, and victim activity. Since the 1900s, there have been 5034 reported shark attacks, of which 1205 (22.7%) were fatal. Although the incidence of attacks per decade has increased, the percentage of fatalities has decreased. Characteristics of fatal attacks included swimming (p = 0.001), boating (p = 0.001), three or more bite sites (p = 0.03), limb loss (p = 0.001), or tiger shark attack (p = 0.002). The most common attacks were bites to the legs (41.8%) or arms (18.4%), with limb loss occurring in 7% of attacks. Geographically, the majority of attacks occurred in North America (36.7%) and Australia (26.5%). Most attacks in the USA occurred in Florida (49.1%) and California (13.6%). Although rare, shark attacks result in devastating injuries to patients. As these injuries often involve multiple sites and limb loss, this creates a significant challenge for reconstructive surgeons. Proper identification of the characteristics of the attack can aid in providing optimal care for those affected. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Hereditary Angioedema Attacks Resolve Faster and Are Shorter after Early Icatibant Treatment

PubMed Central

Maurer, Marcus; Kaplan, Allen; Investigators, on behalf of I. O. S.

2013-01-01

Background Attacks of hereditary angioedema (HAE) are unpredictable and, if affecting the upper airway, can be lethal. Icatibant is used for physician- or patient self-administered symptomatic treatment of HAE attacks in adults. Its mode of action includes disruption of the bradykinin pathway via blockade of the bradykinin B2 receptor. Early treatment is believed to shorten attack duration and prevent severe outcomes; however, evidence to support these benefits is lacking. Objective To examine the impact of timing of icatibant administration on the duration and resolution of HAE type I and II attacks. Methods The Icatibant Outcome Survey is an international, prospective, observational study for patients treated with icatibant. Data on timings and outcomes of icatibant treatment for HAE attacks were collected between July 2009–February 2012. A mixed-model of repeated measures was performed for 426 attacks in 136 HAE type I and II patients. Results Attack duration was significantly shorter in patients treated <1 hour of attack onset compared with those treated ≥1 hour (6.1 hours versus 16.8 hours [p<0.001]). Similar significant effects were observed for <2 hours versus ≥2 hours (7.2 hours versus 20.2 hours [p<0.001]) and <5 hours versus ≥5 hours (8.0 hours versus 23.5 hours [p<0.001]). Treatment within 1 hour of attack onset also significantly reduced time to attack resolution (5.8 hours versus 8.8 hours [p<0.05]). Self-administrators were more likely to treat early and experience shorter attacks than those treated by a healthcare professional. Conclusion Early blockade of the bradykinin B2 receptor with icatibant, particularly within the first hour of attack onset, significantly reduced attack duration and time to attack resolution. PMID:23390491

Adaptive optimisation-offline cyber attack on remote state estimator

NASA Astrophysics Data System (ADS)

Huang, Xin; Dong, Jiuxiang

2017-10-01

Security issues of cyber-physical systems have received increasing attentions in recent years. In this paper, deception attacks on the remote state estimator equipped with the chi-squared failure detector are considered, and it is assumed that the attacker can monitor and modify all the sensor data. A novel adaptive optimisation-offline cyber attack strategy is proposed, where using the current and previous sensor data, the attack can yield the largest estimation error covariance while ensuring to be undetected by the chi-squared monitor. From the attacker's perspective, the attack is better than the existing linear deception attacks to degrade the system performance. Finally, some numerical examples are provided to demonstrate theoretical results.

[Evaluation of four dark object atmospheric correction methods based on ZY-3 CCD data].

PubMed

Guo, Hong; Gu, Xing-fa; Xie, Yong; Yu, Tao; Gao, Hai-liang; Wei, Xiang-qin; Liu, Qi-yue

2014-08-01

The present paper performed the evaluation of four dark-object subtraction(DOS) atmospheric correction methods based on 2012 Inner Mongolia experimental data The authors analyzed the impacts of key parameters of four DOS methods when they were applied to ZY-3 CCD data The results showed that (1) All four DOS methods have significant atmospheric correction effect at band 1, 2 and 3. But as for band 4, the atmospheric correction effect of DOS4 is the best while DOS2 is the worst; both DOS1 and DOS3 has no obvious atmospheric correction effect. (2) The relative error (RE) of DOS1 atmospheric correction method is larger than 10% at four bands; The atmospheric correction effect of DOS2 works the best at band 1(AE (absolute error)=0.0019 and RE=4.32%) and the worst error appears at band 4(AE=0.0464 and RE=19.12%); The RE of DOS3 is about 10% for all bands. (3) The AE of atmospheric correction results for DOS4 method is less than 0. 02 and the RE is less than 10% for all bands. Therefore, the DOS4 method provides the best accuracy of atmospheric correction results for ZY-3 image.

Public knowledge of heart attack symptoms in Beijing residents.

PubMed

Zhang, Qing-Tan; Hu, Da-Yi; Yang, Jin-Gang; Zhang, Shou-Yan; Zhang, Xin-Quan; Liu, Shu-Shan

2007-09-20

Definitive treatment for heart attack is early reperfusion with either angioplasty or thrombolytic therapy, and the benefit is strictly time-dependent. Patient outcomes are improved with either therapy when initiated as soon as possible. Recognition of heart attack symptoms is logically tied to taking action to receive prompt emergency care. Inadequate knowledge of heart attack symptoms may prolong delay. The purpose of this study was to document knowledge about heart attack symptoms in Beijing residents and to identify the characteristics associated with increased knowledge of heart attack. A structured survey was conducted in 18 communities in Beijing from March 1 through June 10 in 2006. Addresses and participants were selected randomly following a stratification. The survey was designed to collect knowledge of heart attack symptoms from sampled adults in each community. A total of 4627 respondents completed the questionnaires correctly, and 50.29% of them were female. Totally 64.15% of the respondents reported chest pain or discomfort (common symptoms) as a symptom of heart attack; 75.38% reported at least one of the following eight symptoms as a symptom of heart attack: back pain, shortness of breath, arm pain or numbness, nausea or vomiting, neck, jaw or shoulder pain, epigastric pain, sweating, weakness (less common symptoms); 20.36% correctly reported four or more heart attack symptoms, only 7.4% knew all the correct heart attack symptoms, and 28.94% knew about reperfusion therapy for heart attack; 31.7% reported to call 120 or 999 while having a heart attack themselves; however 89.6% reported to call 120 or 999 when someone else is suffering from a heart attack. Very old persons and those with health insurance coverage, high education level, high household income, longer living in Beijing and previous experience with heart disease had greater knowledge of heart attack symptoms. Public knowledge of common heart attack symptoms as well as less common heart attack symptoms is deficient in Beijing residents. But their knowledge of calling emergency medical services when someone is having a heart attack is relatively adequate. Public health efforts are needed to increase the recognition of the major heart attack symptoms in both the general public and groups at high risk for an acute cardiac event, especially in socioeconomically disadvantaged subgroups, including persons with low education level, low household income, and no health insurance coverage.

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.

An Approach for Assessing Consequences of Potential Supply Chain and Insider Contributed Cyber Attacks on Nuclear Power Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, Tsong L.

The Stuxnet attack at the Natanz facility is an example of a targeted and successful cyber attack on a nuclear facility. Snowden's release of National Security Agency documents demonstrated the consequences of the insider threat. More recently, the United States tried to attack North Korea but failed, South Korea was attempting to attack North Korea, and both applied Stuxnet-like approaches. These sophisticated targeted attacks differ from web-site hacking events that are reported almost daily in the news mainly because targeted attacks require detailed design and operation information of the systems attacked and/or are often carried out by insiders. For instance,more » in order to minimize disruption of facilities around the world, Stuxnet remained idle until it recognized the specific configuration of the Natanz facility, demonstrating that the attackers possessed extremely detailed information about the facility. Such targeted cyber attacks could become a national-level military weapon and be used in coercion of hostile countries.« less

Improving the Rainbow Attack by Reusing Colours

NASA Astrophysics Data System (ADS)

Ågren, Martin; Johansson, Thomas; Hell, Martin

Hashing or encrypting a key or a password is a vital part in most network security protocols. The most practical generic attack on such schemes is a time memory trade-off attack. Such an attack inverts any one-way function using a trade-off between memory and execution time. Existing techniques include the Hellman attack and the rainbow attack, where the latter uses different reduction functions ("colours") within a table.

Simulation of Attacks for Security in Wireless Sensor Network

PubMed Central

Diaz, Alvaro; Sanchez, Pablo

2016-01-01

The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN) require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node’s software execution time and power consumption estimation). After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work. PMID:27869710

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…

The anatomy of a shark attack: a case report and review of the literature.

PubMed

Caldicott, D G; Mahajani, R; Kuhn, M

2001-07-01

Shark attacks are rare but are associated with a high morbidity and significant mortality. We report the case of a patient's survival from a shark attack and their subsequent emergency medical and surgical management. Using data from the International Shark Attack File, we review the worldwide distribution and incidence of shark attack. A review of the world literature examines the features which make shark attacks unique pathological processes. We offer suggestions for strategies of management of shark attack, and techniques for avoiding adverse outcomes in human encounters with these endangered creatures.

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.

Novel Method For Low-Rate Ddos Attack Detection

NASA Astrophysics Data System (ADS)

Chistokhodova, A. A.; Sidorov, I. D.

2018-05-01

The relevance of the work is associated with an increasing number of advanced types of DDoS attacks, in particular, low-rate HTTP-flood. Last year, the power and complexity of such attacks increased significantly. The article is devoted to the analysis of DDoS attacks detecting methods and their modifications with the purpose of increasing the accuracy of DDoS attack detection. The article details low-rate attacks features in comparison with conventional DDoS attacks. During the analysis, significant shortcomings of the available method for detecting low-rate DDoS attacks were found. Thus, the result of the study is an informal description of a new method for detecting low-rate denial-of-service attacks. The architecture of the stand for approbation of the method is developed. At the current stage of the study, it is possible to improve the efficiency of an already existing method by using a classifier with memory, as well as additional information.

An entangling-probe attack on Shor's algorithm for factorization

NASA Astrophysics Data System (ADS)

Azuma, Hiroo

2018-02-01

We investigate how to attack Shor's quantum algorithm for factorization with an entangling probe. We show that an attacker can steal an exact solution of Shor's algorithm outside an institute where the quantum computer is installed if he replaces its initialized quantum register with entangled qubits, namely the entangling probe. He can apply arbitrary local operations to his own probe. Moreover, we assume that there is an unauthorized person who helps the attacker to commit a crime inside the institute. He tells garbage data obtained from measurements of the quantum register to the attacker secretly behind a legitimate user's back. If the attacker succeeds in cracking Shor's algorithm, the legitimate user obtains a random answer and does not notice the attacker's illegal acts. We discuss how to detect the attacker. Finally, we estimate a probability that the quantum algorithm inevitably makes an error, of which the attacker can take advantage.

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

PubMed

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

2008-10-01

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

Command Disaggregation Attack and Mitigation in Industrial Internet of Things

PubMed Central

Zhu, Pei-Dong; Hu, Yi-Fan; Cui, Peng-Shuai; Zhang, Yan

2017-01-01

A cyber-physical attack in the industrial Internet of Things can cause severe damage to physical system. In this paper, we focus on the command disaggregation attack, wherein attackers modify disaggregated commands by intruding command aggregators like programmable logic controllers, and then maliciously manipulate the physical process. It is necessary to investigate these attacks, analyze their impact on the physical process, and seek effective detection mechanisms. We depict two different types of command disaggregation attack modes: (1) the command sequence is disordered and (2) disaggregated sub-commands are allocated to wrong actuators. We describe three attack models to implement these modes with going undetected by existing detection methods. A novel and effective framework is provided to detect command disaggregation attacks. The framework utilizes the correlations among two-tier command sequences, including commands from the output of central controller and sub-commands from the input of actuators, to detect attacks before disruptions occur. We have designed components of the framework and explain how to mine and use these correlations to detect attacks. We present two case studies to validate different levels of impact from various attack models and the effectiveness of the detection framework. Finally, we discuss how to enhance the detection framework. PMID:29065461

Command Disaggregation Attack and Mitigation in Industrial Internet of Things.

PubMed

Xun, Peng; Zhu, Pei-Dong; Hu, Yi-Fan; Cui, Peng-Shuai; Zhang, Yan

2017-10-21

A cyber-physical attack in the industrial Internet of Things can cause severe damage to physical system. In this paper, we focus on the command disaggregation attack, wherein attackers modify disaggregated commands by intruding command aggregators like programmable logic controllers, and then maliciously manipulate the physical process. It is necessary to investigate these attacks, analyze their impact on the physical process, and seek effective detection mechanisms. We depict two different types of command disaggregation attack modes: (1) the command sequence is disordered and (2) disaggregated sub-commands are allocated to wrong actuators. We describe three attack models to implement these modes with going undetected by existing detection methods. A novel and effective framework is provided to detect command disaggregation attacks. The framework utilizes the correlations among two-tier command sequences, including commands from the output of central controller and sub-commands from the input of actuators, to detect attacks before disruptions occur. We have designed components of the framework and explain how to mine and use these correlations to detect attacks. We present two case studies to validate different levels of impact from various attack models and the effectiveness of the detection framework. Finally, we discuss how to enhance the detection framework.

Lethality of sea lamprey attacks on lake trout in relation to location on the body surface

USGS Publications Warehouse

Bergstedt, Roger A.; Schneider, Clifford P.; O'Gorman, Robert

2001-01-01

We compared the locations of healed attack marks of the sea lamprey Petromyzon marinus on live lake trout Salvelinus namaycush with those of unhealed attack marks on dead lake trout to determine if the lethality of a sea lamprey attack was related to attack location. Lake trout were collected from Lake Ontario, live fish with gill nets in September 1985 and dead fish with trawls in October 1983−1986. Attack location was characterized by the percent distances from snout to tail and from the ventral to the dorsal midline. Kolmogorov−Smirnov two-sample tests did not detect significant differences in the distribution of attack location along either the anteroposterior axis or the dorsoventral axis. When attack locations were grouped into six anatomical regions historically used to record sea lamprey attacks, dead fish did not exhibit a significantly higher proportion of attacks in the more anterior regions. Even if the differences in attack location on live and dead fish were significant, they were too small to imply substantial spatial differences in attack lethality that should be accounted for when modeling the effects of sea lampreys feeding on lake trout. We suggest that the tendency for sea lamprey attacks to occur on the anterior half of the fish is related to the lower amplitude of lateral body movement there during swimming and thus the lower likelihood of being dislodged.

Serial agonistic attacks by greylag goose families, Anser anser, against the same opponent

PubMed Central

Scheiber, Isabella B.R.; Kotrschal, Kurt; Weiß, Brigitte M.

2011-01-01

It is known from primates that alliance partners may support each other’s interests in competition with others, for example, through repeated agonistic attacks against a particular individual. We examined serial aggressive interactions between greylag goose families and other flock members. We found that repeated attacks towards the same individual were common and that up to five serial attacks by family members followed an initial attack. Family size did not affect the frequency of such serial attacks. Juvenile geese evidently benefited most from active social support through serial attacks. About 60% of the juveniles’ lost primary interactions were subsequently reversed by another family member. This may be one of the reasons why juveniles rank higher in the social hierarchy than would be expected from their age and size alone. Losses in serial attacks predominantly occurred against other, presumably higher-ranking, family geese and ganders. We propose three major functions/consequences of serial attacks. Analogous to primates, serial attacks in greylag geese may serve to reinforce a losing experience of an opponent defeated in a preceding attack. On the side of the winning family, serial attacks may reinforce the experience of winning. Both winning and losing experiences are linked with physiological consequences in higher vertebrates, affecting the future social performance of winners or losers. Finally, serial attacks may signal the agonistic potential of a family to other flock members. This is supported by heart rate data, which indicate that greylags are competent to interpret third-party relationships. PMID:21984838

Khyâl attacks: a key idiom of distress among traumatized cambodia refugees.

PubMed

Hinton, Devon E; Pich, Vuth; Marques, Luana; Nickerson, Angela; Pollack, Mark H

2010-06-01

Traumatized Cambodian refugees with PTSD often complain of khyâl attacks. The current study investigates khyâl attacks from multiple perspectives and examines the validity of a model of how khyâl attacks are generated. The study found that khyâl attacks had commonly been experienced in the previous 4 weeks and that their severity was strongly correlated with the severity of PTSD (PTSD Checklist). It was found that khyâl attacks were triggered by various processes--such as worry, trauma recall, standing up, going to a mall--and that khyâl attacks almost always met panic attack criteria. It was also found that during a khyâl attack there was great fear that death might occur from bodily dysfunction. It was likewise found that a complex nosology of khyâl attacks exists that rates the attacks on a scale of severity, that the severity determines how the khyâl attacks should be treated and that those treatments are often complex. As illustrated by the article, khyâl attacks constitute a key aspect of trauma ontology in this group, a culturally specific experiencing of anxiety and trauma-related disorder. The article also contributes to the study of trauma somatics, that is, to the study of how trauma results in specific symptoms in a specific cultural context, showing that a key part of the trauma-somatic reticulum is often a cultural syndrome.

Cyber attacks against state estimation in power systems: Vulnerability analysis and protection strategies

NASA Astrophysics Data System (ADS)

Liu, Xuan

Power grid is one of the most critical infrastructures in a nation and could suffer a variety of cyber attacks. With the development of Smart Grid, false data injection attack has recently attracted wide research interest. This thesis proposes a false data attack model with incomplete network information and develops optimal attack strategies for attacking load measurements and the real-time topology of a power grid. The impacts of false data on the economic and reliable operations of power systems are quantitatively analyzed in this thesis. To mitigate the risk of cyber attacks, a distributed protection strategies are also developed. It has been shown that an attacker can design false data to avoid being detected by the control center if the network information of a power grid is known to the attacker. In practice, however, it is very hard or even impossible for an attacker to obtain all network information of a power grid. In this thesis, we propose a local load redistribution attacking model based on incomplete network information and show that an attacker only needs to obtain the network information of the local attacking region to inject false data into smart meters in the local region without being detected by the state estimator. A heuristic algorithm is developed to determine a feasible attacking region by obtaining reduced network information. This thesis investigates the impacts of false data on the operations of power systems. It has been shown that false data can be designed by an attacker to: 1) mask the real-time topology of a power grid; 2) overload a transmission line; 3) disturb the line outage detection based on PMU data. To mitigate the risk of cyber attacks, this thesis proposes a new protection strategy, which intends to mitigate the damage effects of false data injection attacks by protecting a small set of critical measurements. To further reduce the computation complexity, a mixed integer linear programming approach is also proposed to separate the power grid into several subnetworks, then distributed protection strategy is applied to each subnetwork.

Public knowledge of heart attack in a Nepalese population survey.

PubMed

Limbu, Yuba R; Malla, Rabi; Regmi, Shyam R; Dahal, Ramesh; Nakarmi, Hari L; Yonzan, Ganesh; Gartaula, Ritu P

2006-01-01

Limited knowledge of heart attack symptoms may prevent patients from seeking time-dependent thrombolytic therapy, an intervention that offers impressive survival benefit. Previous studies carried out in developed countries demonstrated a deficit of knowledge about a wide range of heart attack symptoms. The aim of this study was to describe knowledge of heart attack, knowledge of heart attack symptoms, and anticipated first response to symptoms among the lay public in Nepal. A total of 1192 participants (657 men and 535 women age 16 to 88 years old) were interviewed in a cross-sectional manner. Those <16 years of age, all health professionals, and individuals with a history of heart attack were excluded. A total of 862 (72.3%) participants had heard of heart attack. Significantly more male than female participants had heard of heart attack (P <.001). Of the respondents, 91.7% with >or=10 years of education (ED-2) had heard of heart of attack, whereas only 54% respondents with <10 years of education or who were illiterate (unable to read and write) (ED-1) had heard of heart attack, and in both the male and female populations, a higher percentage of the ED-2 group had heard of heart attack than the ED-1 group (92.6% vs. 60% and 85.6% vs. 49.6%, respectively). A significantly higher number of respondents from 31 to 50 years of age (AGE-2) had heard of heart attack than those 16 to 30 years of age (AGE-1) and those >50 years of age (AGE-3) (P <.001). Among 862 respondents who had heard of heart attack, 21.3% could not name any heart attack symptoms. A total of 16 different heart attack symptoms were named. Fainting or collapsing (48%), chest pain (22.4%), shortness of breath (9%), dizziness (8.4%), palpitations (7.4%), and sweating (7.4%) were the leading symptoms named by respondents. Fainting or collapsing and chest pain and shortness of breath were named more frequently among the ED-2 group respondents and the AGE-3 group men. Only 3.7% could name >or=2 typical heart attack symptoms. A significantly larger number of the ED-2 group named >or=2 typical symptoms than their counterparts (P <0.001). A large number (77.6%) of respondents preferred immediate hospital referral and/or doctor consultation after a heart attack. In Nepal, better-educated men are more aware of heart attack. Fainting or collapsing and chest pain and shortness of breath were leading heart attack symptoms named by the general population. Public heart attack awareness is not adequate and knowledge of wide range of heart attack symptoms is deficient in the Nepalese general population.

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 ...

The effect of climate variability on urinary stone attacks: increased incidence associated with temperature over 18 °C: a population-based study.

PubMed

Park, Hyoung Keun; Bae, Sang Rak; Kim, Satbyul E; Choi, Woo Suk; Paick, Sung Hyun; Ho, Kim; Kim, Hyeong Gon; Lho, Yong Soo

2015-02-01

The aim of this study was to evaluate the effect of seasonal variation and climate parameters on urinary tract stone attack and investigate whether stone attack is increased sharply at a specific point. Nationwide data of total urinary tract stone attack numbers per month between January 2006 and December 2010 were obtained from the Korean Health Insurance Review and Assessment Service. The effects of climatic factors on monthly urinary stone attack were assessed using auto-regressive integrated moving average (ARIMA) regression method. A total of 1,702,913 stone attack cases were identified. Mean monthly and monthly average daily urinary stone attack cases were 28,382 ± 2,760 and 933 ± 85, respectively. The stone attack showed seasonal trends of sharp incline in June, a peak plateau from July to September, and a sharp decline after September. The correlation analysis showed that ambient temperature (r = 0.557, p < 0.001) and relative humidity (r = 0.513, p < 0.001) were significantly associated with urinary stone attack cases. However, after adjustment for trends and seasonality, ambient temperature was the only climate factor associated with the stone attack cases in ARIMA regression test (p = 0.04). Threshold temperature was estimated as 18.4 °C. Risk of urinary stone attack significantly increases 1.71% (1.02-2.41 %, 95% confidence intervals) with a 1 °C increase of ambient temperature above the threshold point. In conclusion, monthly urinary stone attack cases were changed according to seasonal variation. Among the climates variables, only temperature had consistent association with stone attack and when the temperature is over 18.4 °C, urinary stone attack would be increased sharply.

Reexperiencing symptoms, dissociation, and avoidance behaviors in daily life of patients with PTSD and patients with panic disorder with agoraphobia.

PubMed

Pfaltz, Monique C; Michael, Tanja; Meyer, Andrea H; Wilhelm, Frank H

2013-08-01

Panic attacks are frequently perceived as life threatening. Panic disorder (PD) patients may therefore experience symptoms of posttraumatic stress disorder (PTSD). The authors explored this in 28 healthy controls, 17 PTSD patients, and 24 PD patients with agoraphobia who completed electronic diaries 36 times during 1 week. Patient groups frequently reported dissociation as well as thoughts, memories, and reliving of their trauma or panic attacks. PTSD patients reported more trauma/panic attack thoughts (incidence rate ratio [IRR] = 2.9) and memories (IRR = 2.8) than PD patients. Patient groups relived their trauma or panic attacks equally frequently, and reported comparable bodily reactions and distress associated with trauma or panic attack memories. Clinical groups avoided trauma or panic attack reminders more often than healthy controls (avoidance of trauma- or panic attack-related thoughts (IRR = 8.0); avoidance of things associated with the trauma or panic attack (IRR = 40.7). PD patients avoided trauma or panic attack reminders less often than PTSD patients (avoidance of trauma- or panic attack-related thoughts [IRR = 2.5]; avoidance of things associated with the trauma or panic attack [IRR = 4.1]), yet these differences were nonsignificant when controlling for functional impairment. In conclusion, trauma-like symptoms are common in PD with agoraphobia and panic attacks may be processed similarly as trauma in PTSD. Copyright © 2013 International Society for Traumatic Stress Studies.

False Positive and False Negative Effects on Network Attacks

NASA Astrophysics Data System (ADS)

Shang, Yilun

2018-01-01

Robustness against attacks serves as evidence for complex network structures and failure mechanisms that lie behind them. Most often, due to detection capability limitation or good disguises, attacks on networks are subject to false positives and false negatives, meaning that functional nodes may be falsely regarded as compromised by the attacker and vice versa. In this work, we initiate a study of false positive/negative effects on network robustness against three fundamental types of attack strategies, namely, random attacks (RA), localized attacks (LA), and targeted attack (TA). By developing a general mathematical framework based upon the percolation model, we investigate analytically and by numerical simulations of attack robustness with false positive/negative rate (FPR/FNR) on three benchmark models including Erdős-Rényi (ER) networks, random regular (RR) networks, and scale-free (SF) networks. We show that ER networks are equivalently robust against RA and LA only when FPR equals zero or the initial network is intact. We find several interesting crossovers in RR and SF networks when FPR is taken into consideration. By defining the cost of attack, we observe diminishing marginal attack efficiency for RA, LA, and TA. Our finding highlights the potential risk of underestimating or ignoring FPR in understanding attack robustness. The results may provide insights into ways of enhancing robustness of network architecture and improve the level of protection of critical infrastructures.

The non-trusty clown attack on model-based speaker recognition systems

NASA Astrophysics Data System (ADS)

Farrokh Baroughi, Alireza; Craver, Scott

2015-03-01

Biometric detectors for speaker identification commonly employ a statistical model for a subject's voice, such as a Gaussian Mixture Model, that combines multiple means to improve detector performance. This allows a malicious insider to amend or append a component of a subject's statistical model so that a detector behaves normally except under a carefully engineered circumstance. This allows an attacker to force a misclassification of his or her voice only when desired, by smuggling data into a database far in advance of an attack. Note that the attack is possible if attacker has access to database even for a limited time to modify victim's model. We exhibit such an attack on a speaker identification, in which an attacker can force a misclassification by speaking in an unusual voice, and replacing the least weighted component of victim's model by the most weighted competent of the unusual voice of the attacker's model. The reason attacker make his or her voice unusual during the attack is because his or her normal voice model can be in database, and by attacking with unusual voice, the attacker has the option to be recognized as himself or herself when talking normally or as the victim when talking in the unusual manner. By attaching an appropriately weighted vector to a victim's model, we can impersonate all users in our simulations, while avoiding unwanted false rejections.

Politics and Power in Global Health: The Constituting Role of Conflicts: Comment on "Navigating Between Stealth Advocacy and Unconscious Dogmatism: The Challenge of Researching the Norms, Politics and Power of Global Health".

PubMed

Askheim, Clemet; Heggen, Kristin; Engebretsen, Eivind

2015-10-15

In a recent article, Gorik Ooms has drawn attention to the normative underpinnings of the politics of global health. We claim that Ooms is indirectly submitting to a liberal conception of politics by framing the politics of global health as a question of individual morality. Drawing on the theoretical works of Chantal Mouffe, we introduce a conflictual concept of the political as an alternative to Ooms' conception. Using controversies surrounding medical treatment of AIDS patients in developing countries as a case we underline the opportunity for political changes, through political articulation of an issue, and collective mobilization based on such an articulation. © 2016 by Kerman University of Medical Sciences.

Abdominal contents from two large early cretaceous compsognathids (Dinosauria: Theropoda) demonstrate feeding on confuciusornithids and dromaeosaurids.

PubMed

Xing, Lida; Bell, Phil R; Persons, W Scott; Ji, Shuan; Miyashita, Tetsuto; Burns, Michael E; Ji, Qiang; Currie, Philip J

2012-01-01

Two skeletons of the large compsognathid Sinocalliopteryx gigas include intact abdominal contents. Both specimens come from the Jianshangou Beds of the lower Yixian Formation (Neocomian), Liaoning, China. The holotype of S. gigas preserves a partial dromaeosaurid leg in the abdominal cavity, here attributed to Sinornithosaurus. A second, newly-discovered specimen preserves the remains of at least two individuals of the primitive avialan, Confuciusornis sanctus, in addition to acid-etched bones from a possible ornithischian. Although it cannot be stated whether such prey items were scavenged or actively hunted, the presence of two Confuciusornis in a grossly similar state of digestion suggests they were consumed in rapid succession. Given the lack of clear arboreal adaptations in Sinocalliopteryx, we suggest it may have been an adept stealth hunter.

Teaching the teachers.

PubMed

Zavalkoff, Anne

2002-10-01

SUMMARY This paper presents a conceptual tool designed to help teacher education students think critically about the roots and consequences of personal, parental, community, and institutional resistance to diverse sexual identities and behaviours. To explore the roots of sexualized and gendered prejudice and ground the conceptual tool theoretically, it begins with a careful examination of Judith Butler's work on performativity. The paper then describes and illustrates the conceptual tool. The Continuum of (Subversive) Drag Performance helps stimulate critical thinking about the power implications of people's sexed and gendered performances through its six ranges: Radical, Stealth, Commercial, Passing, Mainstream, and Privileged. Because these ranges are independent of common considerations of "normalcy," they offer teacher education students a relatively unthreatening framework for analyzing conceptions of sexuality and gender that, left unexamined, can contribute to sexism, heterosexism, and homophobia.

Development of Coatings for Radar Absorbing Materials at X-band

NASA Astrophysics Data System (ADS)

Kumar, Abhishek; Singh, Samarjit

2018-03-01

The present review gives a brief account on some of the technical features of radar absorbing materials (RAMs). The paper has been presented with a concentrated approach towards the material aspects for achieving enhanced radar absorption characteristics for its application as a promising candidate in stealth technology and electromagnetic interference (EMI) minimization problems. The effect of metal particles doping/dispersion in the ferrites and dielectrics has been discussed for obtaining tunable radar absorbing characteristics. A short theoretical overview on the development of absorber materials, implementation of genetic algorithm (GA) in multi-layering and frequency selective surfaces (FSSs) based multi-layer has also been presented for the development of radar absorbing coatings for achieving better absorption augmented with broadband features in order to counter the radar detection systems.

High-frequency CAD-based scattering model: SERMAT

NASA Astrophysics Data System (ADS)

Goupil, D.; Boutillier, M.

1991-09-01

Specifications for an industrial radar cross section (RCS) calculation code are given: it must be able to exchange data with many computer aided design (CAD) systems, it must be fast, and it must have powerful graphic tools. Classical physical optics (PO) and equivalent currents (EC) techniques have proven their efficiency on simple objects for a long time. Difficult geometric problems occur when objects with very complex shapes have to be computed. Only a specific geometric code can solve these problems. We have established that, once these problems have been solved: (1) PO and EC give good results on complex objects of large size compared to wavelength; and (2) the implementation of these objects in a software package (SERMAT) allows fast and sufficiently precise domain RCS calculations to meet industry requirements in the domain of stealth.

Experiments on topographies lacking tidal conversion

NASA Astrophysics Data System (ADS)

Maas, Leo; Paci, Alexandre; Yuan, Bing

2015-11-01

In a stratified sea, internal tides are supposedly generated when the tide passes over irregular topography. It has been shown that for any given frequency in the internal wave band there are an infinite number of exceptions to this rule of thumb. This ``stealth-like'' property of the topography is due to a subtle annihilation of the internal waves generated during the surface tide's passage over the irregular bottom. We here demonstrate this in a lab-experiment. However, for any such topography, subsequently changing the surface tide's frequency does lead to tidal conversion. The upshot of this is that a tidal wave passing over an irregular bottom is for a substantial part trapped to this irregularity, and only partly converted into freely propagating internal tides. Financially supported by the European Community's 7th Framework Programme HYDRALAB IV.

44 CFR 312.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... meaning of the listed terms are as follows: (a) The term attack means any attack or series of attacks by... population caused, or which would be caused, by an attack upon the United States, or by natural disaster, (2) to deal with the immediate emergency conditions which would be created by any such attack, or natural...

44 CFR 312.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... meaning of the listed terms are as follows: (a) The term attack means any attack or series of attacks by... population caused, or which would be caused, by an attack upon the United States, or by natural disaster, (2) to deal with the immediate emergency conditions which would be created by any such attack, or natural...

44 CFR 312.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... meaning of the listed terms are as follows: (a) The term attack means any attack or series of attacks by... population caused, or which would be caused, by an attack upon the United States, or by natural disaster, (2) to deal with the immediate emergency conditions which would be created by any such attack, or natural...

[Comparative analysis of phenomenology of paroxysms of atrial fibrillation and panic attacks].

PubMed

San'kova, T A; Solov'eva, A D; Nedostup, A V

2004-01-01

To study phenomenology of attacks of atrial fibrillation (AF) and to compare it with phenomenology of panic attacks for elucidation of pathogenesis of atrial fibrillation and for elaboration of rational therapeutic intervention including those aimed at correction of psychovegetative abnormalities. Patients with nonrheumatic paroxysmal AF (n=105) and 100 patients with panic attacks (n=100). Clinical, cardiological and neurological examination, analysis of patients complaints during attacks of AF, and comparison them with diagnostic criteria for panic attack. It was found that clinical picture of attacks of AF comprised vegetative, emotional and functional neurological phenomena similar to those characteristic for panic attacks. This similarity as well as positive therapeutic effect of clonazepam allowed to propose a novel pathogenic mechanism of AF attacks. Severity of psychovegetative disorders during paroxysm of AF could be evaluated by calculation of psychovegetative iudex: Psychovegetative index should be used for detection of panic attack-like component in clinical picture of AF paroxysm and thus for determination of indications for inclusion of vegetotropic drugs, e. g. clonazepam, in complex preventive therapy.

Security Assessment of Cyberphysical Digital Microfluidic Biochips.

PubMed

Ali, Sk Subidh; Ibrahim, Mohamed; Sinanoglu, Ozgur; Chakrabarty, Krishnendu; Karri, Ramesh

2016-01-01

A digital microfluidic biochip (DMFB) is an emerging technology that enables miniaturized analysis systems for point-of-care clinical diagnostics, DNA sequencing, and environmental monitoring. A DMFB reduces the rate of sample and reagent consumption, and automates the analysis of assays. In this paper, we provide the first assessment of the security vulnerabilities of DMFBs. We identify result-manipulation attacks on a DMFB that maliciously alter the assay outcomes. Two practical result-manipulation attacks are shown on a DMFB platform performing enzymatic glucose assay on serum. In the first attack, the attacker adjusts the concentration of the glucose sample and thereby modifies the final result. In the second attack, the attacker tampers with the calibration curve of the assay operation. We then identify denial-of-service attacks, where the attacker can disrupt the assay operation by tampering either with the droplet-routing algorithm or with the actuation sequence. We demonstrate these attacks using a digital microfluidic synthesis simulator. The results show that the attacks are easy to implement and hard to detect. Therefore, this work highlights the need for effective protections against malicious modifications in DMFBs.

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

PubMed

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

2007-01-01

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. 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. 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. 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.

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

Robustness analysis of interdependent networks under multiple-attacking strategies

NASA Astrophysics Data System (ADS)

Gao, Yan-Li; Chen, Shi-Ming; Nie, Sen; Ma, Fei; Guan, Jun-Jie

2018-04-01

The robustness of complex networks under attacks largely depends on the structure of a network and the nature of the attacks. Previous research on interdependent networks has focused on two types of initial attack: random attack and degree-based targeted attack. In this paper, a deliberate attack function is proposed, where six kinds of deliberate attacking strategies can be derived by adjusting the tunable parameters. Moreover, the robustness of four types of interdependent networks (BA-BA, ER-ER, BA-ER and ER-BA) with different coupling modes (random, positive and negative correlation) is evaluated under different attacking strategies. Interesting conclusions could be obtained. It can be found that the positive coupling mode can make the vulnerability of the interdependent network to be absolutely dependent on the most vulnerable sub-network under deliberate attacks, whereas random and negative coupling modes make the vulnerability of interdependent network to be mainly dependent on the being attacked sub-network. The robustness of interdependent network will be enhanced with the degree-degree correlation coefficient varying from positive to negative. Therefore, The negative coupling mode is relatively more optimal than others, which can substantially improve the robustness of the ER-ER network and ER-BA network. In terms of the attacking strategies on interdependent networks, the degree information of node is more valuable than the betweenness. In addition, we found a more efficient attacking strategy for each coupled interdependent network and proposed the corresponding protection strategy for suppressing cascading failure. Our results can be very useful for safety design and protection of interdependent networks.

Continuous-variable quantum cryptography is secure against non-Gaussian attacks.

PubMed

Grosshans, Frédéric; Cerf, Nicolas J

2004-01-30

A general study of arbitrary finite-size coherent attacks against continuous-variable quantum cryptographic schemes is presented. It is shown that, if the size of the blocks that can be coherently attacked by an eavesdropper is fixed and much smaller than the key size, then the optimal attack for a given signal-to-noise ratio in the transmission line is an individual Gaussian attack. Consequently, non-Gaussian coherent attacks do not need to be considered in the security analysis of such quantum cryptosystems.

A comparison of the nature and correlates of panic attacks in the context of Panic Disorder and Social Anxiety Disorder.

PubMed

Brown, Lily A; LeBeau, Richard; Liao, Betty; Niles, Andrea N; Glenn, Daniel; Craske, Michelle G

2016-01-30

Panic attacks occurring outside of Panic Disorder are not well-understood despite their inclusion as a diagnostic specifier in the Diagnostic and Statistical Manual for Mental Disorders (DSM-5). This study compares panic attacks in the context of Panic Disorder compared to social anxiety in terms of their symptom frequency, severity, and clinical correlates. Participants (n=404) were interviewed using the Anxiety Disorders Interview Schedule (ADIS-IV-L; Brown et al., 1994), from which we analyzed interviewer ratings of panic attacks and panic attack symptoms, as well as other demographic and clinical characteristics. Panic attacks in the context of Panic Disorder were characterized by a greater number and severity of symptoms compared to panic attacks in the context of Social Anxiety Disorder, and were associated with a history of traumatization, inpatient psychiatric treatment, and benzodiazepine use. Social anxiety panic attacks were associated with reduced physical health concerns. Cognitive panic attack symptoms were more prevalent in Panic Disorder and were associated with a variety of poor clinical correlates. Panic attacks in the context of Panic Disorder are more severe than those in social anxiety, and this may be driven by cognitive disturbances during those attacks. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Heart Attack Recovery FAQs

MedlinePlus

... recommendations to make a full recovery. View an animation of a heart attack . Heart Attack Recovery Questions ... Support Network Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

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.

Sensitivity to carbon dioxide in subjects with a single lifetime panic attack: possible clinical "bedside" predictive test for panic disorder after a first attack.

PubMed

Berzak, Elina; Reznik, Mila; Narsia, Oxana; Benjamin, Jonathan

2004-01-01

There is currently no way of knowing whether a patient who has recently had a single panic attack has incipient panic disorder. Sensitivity to carbon dioxide (CO2) is lower in healthy volunteers than in panic disorder patients. If this is also true of people who experience a single lifetime panic attack, it could be used as a prognostic test. Subjects with a single lifetime panic attack and subjects with panic disorder received an inhalation of 35% CO2. Subjects completed the panic symptoms scale (PSS), and also stated whether they considered that they had experienced an attack. None of 14 subjects with a single lifetime panic attack, compared to 7 of 17 subjects with panic disorder (P=.009), had an attack. The PSS also distinguished between the groups. The 35% CO2 challenge warrants further investigation as a predictive test after a first panic attack.

Exploiting Small Leakages in Masks to Turn a Second-Order Attack into a First-Order Attack and Improved Rotating Substitution Box Masking with Linear Code Cosets.

PubMed

DeTrano, Alexander; Karimi, Naghmeh; Karri, Ramesh; Guo, Xiaofei; Carlet, Claude; Guilley, Sylvain

2015-01-01

Masking countermeasures, used to thwart side-channel attacks, have been shown to be vulnerable to mask-extraction attacks. State-of-the-art mask-extraction attacks on the Advanced Encryption Standard (AES) algorithm target S-Box recomputation schemes but have not been applied to scenarios where S-Boxes are precomputed offline. We propose an attack targeting precomputed S-Boxes stored in nonvolatile memory. Our attack targets AES implemented in software protected by a low entropy masking scheme and recovers the masks with 91% success rate. Recovering the secret key requires fewer power traces (in fact, by at least two orders of magnitude) compared to a classical second-order attack. Moreover, we show that this attack remains viable in a noisy environment or with a reduced number of leakage points. Eventually, we specify a method to enhance the countermeasure by selecting a suitable coset of the masks set.

The effect of nursing professional pay structures and pay levels on hospitals' heart attack outcomes.

PubMed

Brown, Mark P

2006-01-01

The effect of nursing professionals (i.e., nurse aid/orderly, licensed practical nurse, registered nurse) pay structures and pay levels on hospitals risk-adjusted heart attack outcomes was determined. Operationalizing hospitals' heart attack outcomes as their thirty-day risk-adjusted mortality rates, a positive curvilinear relation is hypothesized between pay dispersion and hospitals' heart attack outcomes, whereas a direct relation is hypothesized between pay level and hospitals' heart attack outcomes. Pay level is also hypothesized as a moderator of the relation between pay dispersion and hospitals' heart attack outcomes. Using a sample of 138 California hospitals, support is not found for either the curvilinear relation between hospitals' nursing professionals pay dispersion and hospitals' heart attack outcomes, or the direct relation between nursing professionals' pay level and hospitals' heart attack outcomes. Support is found for the moderation hypothesis in which nursing professionals' pay level moderates the relation between hospitals' nursing professionals pay dispersion and hospitals' heart attack outcomes. Implications for practice are discussed in light of the study's results.

Exploiting Small Leakages in Masks to Turn a Second-Order Attack into a First-Order Attack and Improved Rotating Substitution Box Masking with Linear Code Cosets

PubMed Central

DeTrano, Alexander; Karimi, Naghmeh; Karri, Ramesh; Guo, Xiaofei; Carlet, Claude; Guilley, Sylvain

2015-01-01

Masking countermeasures, used to thwart side-channel attacks, have been shown to be vulnerable to mask-extraction attacks. State-of-the-art mask-extraction attacks on the Advanced Encryption Standard (AES) algorithm target S-Box recomputation schemes but have not been applied to scenarios where S-Boxes are precomputed offline. We propose an attack targeting precomputed S-Boxes stored in nonvolatile memory. Our attack targets AES implemented in software protected by a low entropy masking scheme and recovers the masks with 91% success rate. Recovering the secret key requires fewer power traces (in fact, by at least two orders of magnitude) compared to a classical second-order attack. Moreover, we show that this attack remains viable in a noisy environment or with a reduced number of leakage points. Eventually, we specify a method to enhance the countermeasure by selecting a suitable coset of the masks set. PMID:26491717

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

Heart Attack

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Each year almost 800,000 Americans have a heart attack. A heart attack happens when blood flow to the heart suddenly ... it's important to know the symptoms of a heart attack and call 9-1-1 if you or ...

Microvascular Angina

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... to the Terms and Conditions and Privacy Policy Heart Attack Tools & Resources My Cardiac Coach What Is a ... Heart Attack Warning Signs: Patient sheet | Infographic | Quiz Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ...

Using the Domain Name System to Thwart Automated Client-Based Attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Curtis R; Shue, Craig A

2011-09-01

On the Internet, attackers can compromise systems owned by other people and then use these systems to launch attacks automatically. When attacks such as phishing or SQL injections are successful, they can have negative consequences including server downtime and the loss of sensitive information. Current methods to prevent such attacks are limited in that they are application-specific, or fail to block attackers. Phishing attempts can be stopped with email filters, but if the attacker manages to successfully bypass these filters, then the user must determine if the email is legitimate or not. Unfortunately, they often are unable to do so.more » Since attackers have a low success rate, they attempt to compensate for it in volume. In order to have this high throughput, attackers take shortcuts and break protocols. We use this knowledge to address these issues by implementing a system that can detect malicious activity and use it to block attacks. If the client fails to follow proper procedure, they can be classified as an attacker. Once an attacker has been discovered, they will be isolated and monitored. This can be accomplished using existing software in Ubuntu Linux applications, along with our custom wrapper application. After running the system and seeing its performance on three popular Web browsers Chromium, Firefox and Internet Explorer as well as two popular email clients, Thunderbird and Evolution, we found that not only is this system conceivable, it is effective and has low overhead.« less

Incidence and impact of dog attacks on guide dogs in the UK.

PubMed

Brooks, A; Moxon, R; England, G C W

2010-06-19

In a retrospective survey, researchers identified 100 incidents of attacks on guide dogs by other dogs. These were reviewed in order to determine the number, severity and impact on the handler and dog, and the characteristics of the aggressors and victims. During the study period there were more than three attacks reported each month, with 61 per cent of the attacks being upon dogs that were in harness and working with an owner or trainer. The majority of the dogs that were attacked were male (62 per cent), and the breeds that were over-represented (relative to their prevalence in the general guide dog population) were the labrador and the golden retriever x flat-coated retriever crossbreed. Most of the attacks occurred in public places between 09.00 and 15.00 and the majority (61 per cent) of the attacking dogs were off the lead at the time of the attack. Thirty-eight per cent of the attacking dogs were of bull breeds, which were over-represented among attackers compared with the proportion of this breed type in the general dog population. Veterinary attention was sought after 41 per cent of the attacks, and in 19 per cent of instances there was injury to the handler or to a member of the public. The attacks were reported to have affected the working performance and behaviour of the victim dog in 45 per cent of the instances, and two dogs had to be subsequently withdrawn from working as guide dogs.

Robustness and structure of complex networks

NASA Astrophysics Data System (ADS)

Shao, Shuai

This dissertation covers the two major parts of my PhD research on statistical physics and complex networks: i) modeling a new type of attack -- localized attack, and investigating robustness of complex networks under this type of attack; ii) discovering the clustering structure in complex networks and its influence on the robustness of coupled networks. Complex networks appear in every aspect of our daily life and are widely studied in Physics, Mathematics, Biology, and Computer Science. One important property of complex networks is their robustness under attacks, which depends crucially on the nature of attacks and the structure of the networks themselves. Previous studies have focused on two types of attack: random attack and targeted attack, which, however, are insufficient to describe many real-world damages. Here we propose a new type of attack -- localized attack, and study the robustness of complex networks under this type of attack, both analytically and via simulation. On the other hand, we also study the clustering structure in the network, and its influence on the robustness of a complex network system. In the first part, we propose a theoretical framework to study the robustness of complex networks under localized attack based on percolation theory and generating function method. We investigate the percolation properties, including the critical threshold of the phase transition pc and the size of the giant component Pinfinity. We compare localized attack with random attack and find that while random regular (RR) networks are more robust against localized attack, Erdoḧs-Renyi (ER) networks are equally robust under both types of attacks. As for scale-free (SF) networks, their robustness depends crucially on the degree exponent lambda. The simulation results show perfect agreement with theoretical predictions. We also test our model on two real-world networks: a peer-to-peer computer network and an airline network, and find that the real-world networks are much more vulnerable to localized attack compared with random attack. In the second part, we extend the tree-like generating function method to incorporating clustering structure in complex networks. We study the robustness of a complex network system, especially a network of networks (NON) with clustering structure in each network. We find that the system becomes less robust as we increase the clustering coefficient of each network. For a partially dependent network system, we also find that the influence of the clustering coefficient on network robustness decreases as we decrease the coupling strength, and the critical coupling strength qc, at which the first-order phase transition changes to second-order, increases as we increase the clustering coefficient.

Phenomenology of panic attacks: a descriptive study of panic disorder patients' self-reports.

PubMed

Aronson, T A; Logue, C M

1988-01-01

The phenomenology of panic disorder and panic attacks was systematically assessed in 46 consecutive patients. The results suggest that DSM-III criteria include several symptoms that are not frequently present during a panic attack and that DSM-III's characterization of a panic attack is imprecise and misleading. Panic attacks were found to vary in intensity, frequency, spontaneity, and associated symptoms. A panic attack typically presents as a unified symptom complex of psychic anxiety and multiple somatic symptoms in multiple body systems. It occurs in a crescendolike pattern, is self-limited, and often leaves the subject weak or shaken. The temporal course as much as the symptomatic presentation defines a panic attack.

Finite Energy and Bounded Attacks on Control System Sensor Signals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djouadi, Seddik M; Melin, Alexander M; Ferragut, Erik M

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 signalmore » 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.« less

Multi-Layer Approach for the Detection of Selective Forwarding Attacks

PubMed Central

Alajmi, Naser; Elleithy, Khaled

2015-01-01

Security breaches are a major threat in wireless sensor networks (WSNs). WSNs are increasingly used due to their broad range of important applications in both military and civilian domains. WSNs are prone to several types of security attacks. Sensor nodes have limited capacities and are often deployed in dangerous locations; therefore, they are vulnerable to different types of attacks, including wormhole, sinkhole, and selective forwarding attacks. Security attacks are classified as data traffic and routing attacks. These security attacks could affect the most significant applications of WSNs, namely, military surveillance, traffic monitoring, and healthcare. Therefore, there are different approaches to detecting security attacks on the network layer in WSNs. Reliability, energy efficiency, and scalability are strong constraints on sensor nodes that affect the security of WSNs. Because sensor nodes have limited capabilities in most of these areas, selective forwarding attacks cannot be easily detected in networks. In this paper, we propose an approach to selective forwarding detection (SFD). The approach has three layers: MAC pool IDs, rule-based processing, and anomaly detection. It maintains the safety of data transmission between a source node and base station while detecting selective forwarding attacks. Furthermore, the approach is reliable, energy efficient, and scalable. PMID:26610499

Cougar attacks on children: injury patterns and treatment.

PubMed

Kadesky, K M; Manarey, C; Blair, G K; Murphy, J J; Verchere, C; Atkinson, K

1998-06-01

Cougar attacks on humans appear to be on the rise. A review of all attacks on children was performed to determine the method of attack and injury patterns so that a treatment regimen as well as possible preventative measures could be determined. A review of all attacks, including attacks on children, was performed, including three recent attacks treated at our institution. Situation, adult supervision, patient age, injuries recorded, survival, and mode of attack, if known, were reviewed. There were 50 documented attacks on children with a 25% fatality rate. Most children were not alone at the time of the attack (92%), and in many instances adult supervision was present or nearby. Severe head and neck lacerations along with puncture wounds were the most common injury. Examples of typical cervical injuries include a nonfatal vertebral artery injury, phrenic nerve injury, a fatal internal carotid artery injury, and a fatal cervical spine injury. The cougar was rabid in two cases. Pasteurella resulted in late infections in two patients. Based on the pattern of injuries, the authors recommend aggressive evaluation for occult cervical injuries as well as surgical debridement. Antibiotics should cover oropharyngeal flora including Pasteurella multocida. Rabies prophylaxis is indicated. Adult supervision in wilderness areas is not necessarily protective.

Multi-Layer Approach for the Detection of Selective Forwarding Attacks.

PubMed

Alajmi, Naser; Elleithy, Khaled

2015-11-19

Security breaches are a major threat in wireless sensor networks (WSNs). WSNs are increasingly used due to their broad range of important applications in both military and civilian domains. WSNs are prone to several types of security attacks. Sensor nodes have limited capacities and are often deployed in dangerous locations; therefore, they are vulnerable to different types of attacks, including wormhole, sinkhole, and selective forwarding attacks. Security attacks are classified as data traffic and routing attacks. These security attacks could affect the most significant applications of WSNs, namely, military surveillance, traffic monitoring, and healthcare. Therefore, there are different approaches to detecting security attacks on the network layer in WSNs. Reliability, energy efficiency, and scalability are strong constraints on sensor nodes that affect the security of WSNs. Because sensor nodes have limited capabilities in most of these areas, selective forwarding attacks cannot be easily detected in networks. In this paper, we propose an approach to selective forwarding detection (SFD). The approach has three layers: MAC pool IDs, rule-based processing, and anomaly detection. It maintains the safety of data transmission between a source node and base station while detecting selective forwarding attacks. Furthermore, the approach is reliable, energy efficient, and scalable.

Incidence and impact of dog attacks on guide dogs in the UK: an update.

PubMed

Moxon, R; Whiteside, H; England, G C W

2016-04-09

Data on dog attacks on Guide Dogs' stock were reviewed to investigate the characteristics of the attacks. An average of 11.2 attacks occurred each month. Nearly all of the attacks occurred in public areas, 68.4 per cent of victim dogs were qualified guide dogs and 55.5 per cent of victim dogs were working in harness when they were attacked. Guide Dogs' stock were injured in 43.2 per cent of attacks and veterinary costs for attacks were estimated at £34,514.30. Over 40 per cent of qualified guide dogs' working ability was affected and >20 per cent of qualified guide dogs required some time off from working after a dog attack. Twenty dogs were permanently withdrawn from the Guide Dogs' programme as a result of dog attacks, 13 of which were qualified and working with guide dog owners at the time of the withdrawal; this resulted in a financial cost of >£600,000 to the charity. More importantly perhaps, temporary and permanent withdrawals have a significant impact upon the mobility and independence of guide dog owners and in many cases significantly impacted their emotional well-being. British Veterinary Association.

Childhood internalizing and externalizing problems predict the onset of clinical panic attacks over adolescence: the TRAILS study.

PubMed

Mathyssek, Christina M; Olino, Thomas M; Verhulst, Frank C; van Oort, Floor V A

2012-01-01

Panic attacks are a source of individual suffering and are an independent risk factor for later psychopathology. However, much less is known about risk factors for the development of panic attacks, particularly during adolescence when the incidence of panic attacks increases dramatically. We examined whether internalizing and externalizing problems in childhood predict the onset of panic attacks in adolescence. This study is part of the TRacking Adolescents' Individual Lives Survey (TRAILS), a Dutch longitudinal population cohort study (N = 1,584). Internalizing and Externalizing Problems were collected using the Youth Self-Report (YSR) and the parent-report Child Behavior Checklist (CBCL) at baseline (age 10-12). At age 18-20, DSM-IV defined panic attacks since baseline were assessed with the Composite International Diagnostic Interview (CIDI). We investigated whether early adolescent Internalizing and Externalizing Problems predicted panic attacks between ages 10-20 years, using survival analysis in univariate and multivariate models. There were N = 314 (19.8%) cases who experienced at least one DSM-IV defined panic attack during adolescence and N = 18 (1.2%) who developed panic disorder during adolescence. In univariate analyses, CBCL Total Problems, Internalizing Problems and three of the eight syndrome scales predicted panic attack onset, while on the YSR all broad-band problem scales and each narrow-band syndrome scale predicted panic attack onset. In multivariate analyses, CBCL Social Problems (HR 1.19, p<.05), and YSR Thought Problems (HR 1.15, p<.05) and Social Problems (HR 1.26, p<.01) predicted panic attack onset. Risk indicators of panic attack include the wide range of internalizing and externalizing problems. Yet, when adjusted for co-occurring problem behaviors, Social Problems were the most consistent risk factor for panic attack onsets in adolescence.

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.

Unstable Angina

MedlinePlus

... Women This content was last reviewed July 2015. Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ... Recovery FAQs • Heart Attack Tools & Resources • Support Network Heart Attack Tools & Resources My Cardiac Coach What Is a ...

Acute Coronary Syndrome

MedlinePlus

... angina? This content was last reviewed July 2015. Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ... Recovery FAQs • Heart Attack Tools & Resources • Support Network Heart Attack Tools & Resources My Cardiac Coach What Is a ...

Self-regulating the effortful "social dos".

PubMed

Cortes, Kassandra; Kammrath, Lara K; Scholer, Abigail A; Peetz, Johanna

2014-03-01

In the current research, we explored differences in the self-regulation of the personal dos (i.e., engaging in active and effortful behaviors that benefit the self) and in the self-regulation of the social dos (engaging in those same effortful behaviors to benefit someone else). In 6 studies, we examined whether the same trait self-control abilities that predict task persistence on personal dos would also predict task persistence on social dos. That is, would the same behavior, such as persisting through a tedious and attentionally demanding task, show different associations with trait self-control when it is framed as benefitting the self versus someone else? In Studies 1-3, we directly compared the personal and social dos and found that trait self-control predicted self-reported and behavioral personal dos but not social dos, even when the behaviors were identical and when the incentives were matched. Instead, trait agreeableness--a trait linked to successful self-regulation within the social domain--predicted the social dos. Trait self-control did not predict the social dos even when task difficulty increased (Study 4), but it did predict the social don'ts, consistent with past research (Studies 5-6). The current studies provide support for the importance of distinguishing different domains of self-regulated behaviors and suggest that social dos can be successfully performed through routes other than traditional self-control abilities. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

DOS-32 System Manual

DOT National Transportation Integrated Search

1973-06-01

This manual describes the internal workings of the Disk Operating System (DOS-32 for the Noneywell H - 632 computer. DOS - 32 is a core resident, one user, console oriented operating system written primarily in FORTRAN. A companion document DOS - 32 ...

DOS-32 User's Manual

DOT National Transportation Integrated Search

1973-01-01

This manual describes the internal workings of the Disk Operating System (DOS-32 for the Noneywell H - 632 computer. DOS - 32 is a core resident, one user, console oriented operating system written primarily in FORTRAN. A companion document DOS - 32 ...

Analysis of characteristics associated with reinjection of icatibant: Results from the icatibant outcome survey.

PubMed

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

2015-01-01

Phase 3 icatibant trials showed that most hereditary angioedema (HAE) (C1 inhibitor deficiency) acute attacks were treated successfully with one injection of icatibant, a selective bradykinin B2 receptor antagonist. We conducted a post hoc analysis of icatibant reinjection for HAE type I and II attacks in a real-world setting by using data from the Icatibant Outcome Survey, an ongoing observational study that monitors the safety and effectiveness of icatibant treatment. Descriptive retrospective analyses of icatibant reinjection were performed on Icatibant Outcome Survey data (February 2008 to December 2012). New attacks were defined as the onset of new symptoms after full resolution of the previous attack. Potential associations between the patient and attack characteristics and reinjection were explored by using logistic regression analysis. Icatibant was administered for 652 attacks in 170 patients with HAE type I or II. Most attacks (89.1%) were treated with a single icatibant injection. For attacks that required two or three injections, the second injection was given a median of 11.0 hours after the first injection, with 90.4% of second injections administered ≥6 hours after the first injection. Time to resolution and attack duration were significantly longer for two or three injections versus one icatibant injection (p < 0.0001 and p < 0.05, respectively). Multivariate logistic regression analysis identified sex, attack severity, and laryngeal attacks as significantly correlated with reinjection (all p ≤ 0.05). These factors did not remain predictors for reinjection when two outlier patients with distinct patterns of icatibant use were excluded. In this real-world setting, most HAE attacks resolved with one icatibant injection. There was no distinct profile for patients or attacks that required reinjection when outliers with substantially different patterns of use were excluded. Because new attacks were not distinguished from the recurrence of symptoms, reinjection rates may be slightly higher than shown here. Clinical trial identifier: NCT01034969.

Enhanced diffie-hellman algorithm for reliable key exchange

NASA Astrophysics Data System (ADS)

Aryan; Kumar, Chaithanya; Vincent, P. M. Durai Raj

2017-11-01

The Diffie -Hellman is one of the first public-key procedure and is a certain way of exchanging the cryptographic keys securely. This concept was introduced by Ralph Markel and it is named after Whitfield Diffie and Martin Hellman. Sender and Receiver make a common secret key in Diffie-Hellman algorithm and then they start communicating with each other over the public channel which is known to everyone. A number of internet services are secured by Diffie -Hellman. In Public key cryptosystem, the sender has to trust while receiving the public key of the receiver and vice-versa and this is the challenge of public key cryptosystem. Man-in-the-Middle attack is very much possible on the existing Diffie-Hellman algorithm. In man-in-the-middle attack, the attacker exists in the public channel, the attacker receives the public key of both sender and receiver and sends public keys to sender and receiver which is generated by his own. This is how man-in-the-middle attack is possible on Diffie-Hellman algorithm. Denial of service attack is another attack which is found common on Diffie-Hellman. In this attack, the attacker tries to stop the communication happening between sender and receiver and attacker can do this by deleting messages or by confusing the parties with miscommunication. Some more attacks like Insider attack, Outsider attack, etc are possible on Diffie-Hellman. To reduce the possibility of attacks on Diffie-Hellman algorithm, we have enhanced the Diffie-Hellman algorithm to a next level. In this paper, we are extending the Diffie -Hellman algorithm by using the concept of the Diffie -Hellman algorithm to get a stronger secret key and that secret key is further exchanged between the sender and the receiver so that for each message, a new secret shared key would be generated. The second secret key will be generated by taking primitive root of the first secret key.

The panic attack-posttraumatic stress disorder model: applicability to orthostatic panic among Cambodian refugees.

PubMed

Hinton, Devon E; Hofmann, Stefan G; Pitman, Roger K; Pollack, Mark H; Barlow, David H

2008-01-01

This article examines the ability of the panic attack-posttraumatic stress disorder (PTSD) model to predict how panic attacks are generated and how panic attacks worsen PTSD. The article does so by determining the validity of the panic attack-PTSD model in respect to one type of panic attack among traumatized Cambodian refugees: orthostatic panic (OP) attacks (i.e. panic attacks generated by moving from lying or sitting to standing). Among Cambodian refugees attending a psychiatric clinic, the authors conducted two studies to explore the validity of the panic attack-PTSD model as applied to OP patients (i.e. patients with at least one episode of OP in the previous month). In Study 1, the panic attack-PTSD model accurately indicated how OP is seemingly generated: among OP patients (N = 58), orthostasis-associated flashbacks and catastrophic cognitions predicted OP severity beyond a measure of anxious-depressive distress (Symptom Checklist-90-R subscales), and OP severity significantly mediated the effect of anxious-depressive distress on Clinician-Administered PTSD Scale severity. In Study 2, as predicted by the panic attack-PTSD model, OP had a mediational role in respect to the effect of treatment on PTSD severity: among Cambodian refugees with PTSD and comorbid OP who participated in a cognitive behavioural therapy study (N = 56), improvement in PTSD severity was partially mediated by improvement in OP severity.

Epileptic negative drop attacks in atypical benign partial epilepsy: a neurophysiological study.

PubMed

Hirano, Yoshiko; Oguni, Hirokazu; Osawa, Makiko

2009-03-01

We conducted a computer-assisted polygraphic analysis of drop attacks in a child with atypical benign partial epilepsy (ABPE) to investigate neurophysiological characteristics. The patient was a six-year two-month-old girl, who had started to have focal motor seizures, later combined with daily epileptic negative myoclonus (ENM) and drop attacks, causing multiple injuries. We studied episodes of ENM and drop attacks using video-polygraphic and computer-assisted back-averaging analysis. A total of 12 ENM episodes, seven involving the left arm (ENMlt) and five involving both arms (ENMbil), and five drop attacks were captured for analysis. All episodes were time-locked to spike-and-wave complexes (SWC) arising from both centro-temporo-parietal (CTP) areas. The latency between the onset of SWC and ENMlt, ENMbil, and drop attacks reached 68 ms, 42 ms, and 8 ms, respectively. The height of the spike as well as the slow-wave component of SWC for drop attacks were significantly larger than that for both ENMlt and ENMbil (p < 0.05). Drop attacks were considered to be epileptic negative myoclonus involving not only upper proximal but also axial muscles, causing the body to fall. Thus, drop attacks in ABPE are considered to be epileptic negative drop attacks arising from bilateral CTP foci and differ from drop attacks of a generalized origin seen in Lennox-Gastaut syndrome and myoclonic-astatic epilepsy.

Seven Deadliest Network Attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

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, findmore » 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.« less

Dynamic defense and network randomization for computer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chavez, Adrian R.; Stout, William M. S.; Hamlet, Jason R.

The various technologies presented herein relate to determining a network attack is taking place, and further to adjust one or more network parameters such that the network becomes dynamically configured. A plurality of machine learning algorithms are configured to recognize an active attack pattern. Notification of the attack can be generated, and knowledge gained from the detected attack pattern can be utilized to improve the knowledge of the algorithms to detect a subsequent attack vector(s). Further, network settings and application communications can be dynamically randomized, wherein artificial diversity converts control systems into moving targets that help mitigate the early reconnaissancemore » stages of an attack. An attack(s) based upon a known static address(es) of a critical infrastructure network device(s) can be mitigated by the dynamic randomization. Network parameters that can be randomized include IP addresses, application port numbers, paths data packets navigate through the network, application randomization, etc.« less

"MRI Stealth" robot for prostate interventions.

PubMed

Stoianovici, Dan; Song, Danny; Petrisor, Doru; Ursu, Daniel; Mazilu, Dumitru; Muntener, Michael; Mutener, Michael; Schar, Michael; Patriciu, Alexandru

2007-01-01

The paper reports an important achievement in MRI instrumentation, a pneumatic, fully actuated robot located within the scanner alongside the patient and operating under remote control based on the images. Previous MRI robots commonly used piezoelectric actuation limiting their compatibility. Pneumatics is an ideal choice for MRI compatibility because it is decoupled from electromagnetism, but pneumatic actuators were hardly controllable. This achievement was possible due to a recent technology breakthrough, the invention of a new type of pneumatic motor, PneuStep 1, designed for the robot reported here with uncompromised MRI compatibility, high-precision, and medical safety. MrBot is one of the "MRI stealth" robots today (the second is described in this issue by Zangos et al.). Both of these systems are also multi-imager compatible, being able to operate with the imager of choice or cross-imaging modalities. For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, crystals, rubbers and is electricity free. Light-based encoding is used for feedback, so that all electric components are distally located outside the imager's room. MRI robots are modern, digital medical instruments in line with advanced imaging equipment and methods. These allow for accessing patients within closed bore scanners and performing interventions under direct (in scanner) imaging feedback. MRI robots could allow e.g. to biopsy small lesions imaged with cutting edge cancer imaging methods, or precisely deploy localized therapy at cancer foci. Our robot is the first to show the feasibility of fully automated in-scanner interventions. It is customized for the prostate and operates transperineally for needle interventions. It can accommodate various needle drivers for different percutaneous procedures such as biopsy, thermal ablations, or brachytherapy. The first needle driver is customized for fully automated low-dose radiation seed brachytherapy. This paper gives an introduction to the challenges of MRI robot compatibility and presents the solutions adopted in making the MrBot. Its multi-imager compatibility and other preclinical tests are included. The robot shows the technical feasibility of MRI-guided prostate interventions, yet its clinical utility is still to be determined.

Automatic Inference of Cryptographic Key Length Based on Analysis of Proof Tightness

DTIC Science & Technology

2016-06-01

within an attack tree structure, then expand attack tree methodology to include cryptographic reductions. We then provide the algorithms for...maintaining and automatically reasoning about these expanded attack trees . We provide a software tool that utilizes machine-readable proof and attack metadata...and the attack tree methodology to provide rapid and precise answers regarding security parameters and effective security. This eliminates the need

Cyber Signal/Noise Characteristics and Sensor Models for Early Cyber Indications and Warning

DTIC Science & Technology

2005-09-01

investigating and simulating attack scenarios. The sensors are, in effect , mathematical functions. These functions range from simple functions of...172 8.1.2 Examine each attack scenario or case to derive the cause- effect network for the attack scenario...threat profiles............................ 174 8.1.4 Develop attack profiles by enlarging the cause- effect network of each attack scenario with

Attack Coverage in High-Level Men’s Volleyball: Organization on the Edge of Chaos?

PubMed Central

Laporta, Lorenzo; Nikolaidis, Pantelis; Thomas, Luke; Afonso, José

2015-01-01

Change is pervasive, but emerging patterns are occasionally detectable through analysis of systemic behaviors. Match analysis uses these patterns in order to reduce the degree of improvisation and to optimize the training process. However, it is possible that certain game phases elude systematic patterning. In this vein, our aim was to analyze the case of attack coverage in men’s volleyball, as we suspected it would elude systematic patterning and has received negligible attention in scientific research. We analyzed the occurrence of attack coverage in 4544 plays of the 2011 Volleyball World League. A Chi-square test with residual adjusted values was applied to explore significant associations between variables. A Monte Carlo correction was applied, as some cells had n<5. Effect sizes were determined using Cramer’s V. Overall, attack coverage occurred in 3.89% of ball possessions, and 23 distinct structures emerged. These structures lacked significant associations with the game complex, setting zone, and effect of attack coverage. Conversely, attack coverage structures showed significant associations with the attack zone and tempo, with very strong effect sizes (V=0.472 and V=0.521, respectively). As certain attack zones are deeply associated with attack tempo, it is apparent that quicker attack plays affect attack coverage structuring, promoting the formation of less complex structures. Ultimately, attack coverage structures seem to depend on momentary constraints, thereby rendering rigid systematization impracticable. Still, we contended that a principle-based approach might be suitable. This invites researchers to rethink how to interpret game regularities. PMID:26557208

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

Randomness determines practical security of BB84 quantum key distribution.

PubMed

Li, Hong-Wei; Yin, Zhen-Qiang; Wang, Shuang; Qian, Yong-Jun; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu

2015-11-10

Unconditional security of the BB84 quantum key distribution protocol has been proved by exploiting the fundamental laws of quantum mechanics, but the practical quantum key distribution system maybe hacked by considering the imperfect state preparation and measurement respectively. Until now, different attacking schemes have been proposed by utilizing imperfect devices, but the general security analysis model against all of the practical attacking schemes has not been proposed. Here, we demonstrate that the general practical attacking schemes can be divided into the Trojan horse attack, strong randomness attack and weak randomness attack respectively. We prove security of BB84 protocol under randomness attacking models, and these results can be applied to guarantee the security of the practical quantum key distribution system.

Attacks by jaguars (Panthera onca) on humans in central Brazil: report of three cases, with observation of a death.

PubMed

Neto, Manoel Francisco Campos; Garrone Neto, Domingos; Haddad, Vidal

2011-06-01

Conflicts between humans and big cats have been known for centuries throughout the world, but have intensified in recent decades. Recently, attacks by Panthera onca on humans in Brazil have been brought to the forefront through exposure in the press and because of the severity of the attacks. We report 3 cases of patients attacked by jaguars in provoked and predatory situations. Two patients survived the attacks and one died. Attack mechanisms and lesions in victims are discussed. The attacks demonstrate a real risk of accidents from jaguars in certain regions, such as the Pantanal and the Amazon. Copyright © 2011 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Randomness determines practical security of BB84 quantum key distribution

PubMed Central

Li, Hong-Wei; Yin, Zhen-Qiang; Wang, Shuang; Qian, Yong-Jun; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu

2015-01-01

Unconditional security of the BB84 quantum key distribution protocol has been proved by exploiting the fundamental laws of quantum mechanics, but the practical quantum key distribution system maybe hacked by considering the imperfect state preparation and measurement respectively. Until now, different attacking schemes have been proposed by utilizing imperfect devices, but the general security analysis model against all of the practical attacking schemes has not been proposed. Here, we demonstrate that the general practical attacking schemes can be divided into the Trojan horse attack, strong randomness attack and weak randomness attack respectively. We prove security of BB84 protocol under randomness attacking models, and these results can be applied to guarantee the security of the practical quantum key distribution system. PMID:26552359

Randomness determines practical security of BB84 quantum key distribution

NASA Astrophysics Data System (ADS)

Li, Hong-Wei; Yin, Zhen-Qiang; Wang, Shuang; Qian, Yong-Jun; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu

2015-11-01

Unconditional security of the BB84 quantum key distribution protocol has been proved by exploiting the fundamental laws of quantum mechanics, but the practical quantum key distribution system maybe hacked by considering the imperfect state preparation and measurement respectively. Until now, different attacking schemes have been proposed by utilizing imperfect devices, but the general security analysis model against all of the practical attacking schemes has not been proposed. Here, we demonstrate that the general practical attacking schemes can be divided into the Trojan horse attack, strong randomness attack and weak randomness attack respectively. We prove security of BB84 protocol under randomness attacking models, and these results can be applied to guarantee the security of the practical quantum key distribution system.

A Novel Network Attack Audit System based on Multi-Agent Technology

NASA Astrophysics Data System (ADS)

Jianping, Wang; Min, Chen; Xianwen, Wu

A network attack audit system which includes network attack audit Agent, host audit Agent and management control center audit Agent is proposed. And the improved multi-agent technology is carried out in the network attack audit Agent which has achieved satisfactory audit results. The audit system in terms of network attack is just in-depth, and with the function improvement of network attack audit Agent, different attack will be better analyzed and audit. In addition, the management control center Agent should manage and analyze audit results from AA (or HA) and audit data on time. And the history files of network packets and host log data should also be audit to find deeper violations that cannot be found in real time.

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.

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.

Face liveness detection for face recognition based on cardiac features of skin color image

NASA Astrophysics Data System (ADS)

Suh, Kun Ha; Lee, Eui Chul

2016-07-01

With the growth of biometric technology, spoofing attacks have been emerged a threat to the security of the system. Main spoofing scenarios in the face recognition system include the printing attack, replay attack, and 3D mask attack. To prevent such attacks, techniques that evaluating liveness of the biometric data can be considered as a solution. In this paper, a novel face liveness detection method based on cardiac signal extracted from face is presented. The key point of proposed method is that the cardiac characteristic is detected in live faces but not detected in non-live faces. Experimental results showed that the proposed method can be effective way for determining printing attack or 3D mask attack.

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.

Use of Optical Storage Devices as Shared Resources in Local Area Networks

DTIC Science & Technology

1989-09-01

13 3. SERVICE CALLS FOR MS-DOS CD-ROM EXTENSIONS . 14 4. MS-DOS PRIMITIVE GROUPS ....................... 15 5. RAM USAGE FOR VARIOUS LAN...17 2. Service Call Translation to DOS Primitives ............. 19 3. MS-DOS Device Drivers ............................. 21 4. MS-DOS/ROM...directed to I/O devices will be referred to as primitive instruction groups). These primitive instruction groups include keyboard, video, disk, serial

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

MedlinePlus

... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Heart Attack or Sudden Cardiac Arrest: How Are They Different? ... and procedures related to heart disease and stroke. Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ...

Risk Management

DTIC Science & Technology

2011-06-02

actively attack the risks, they will actively attack you.” -Tom Gib Why do Risk Management? 8 “The first step in the risk management process is to...opportunities to manage and improve our chances of success. - Roger Vanscoy “If you do not actively attack the risks, they will actively attack ...our risks provides opportunities to manage and improve our chances of success. - Roger Vanscoy “If you do not actively attack the risks, they will

Experimental implementation of non-Gaussian attacks on a continuous-variable quantum-key-distribution system.

PubMed

Lodewyck, Jérôme; Debuisschert, Thierry; García-Patrón, Raúl; Tualle-Brouri, Rosa; Cerf, Nicolas J; Grangier, Philippe

2007-01-19

An intercept-resend attack on a continuous-variable quantum-key-distribution protocol is investigated experimentally. By varying the interception fraction, one can implement a family of attacks where the eavesdropper totally controls the channel parameters. In general, such attacks add excess noise in the channel, and may also result in non-Gaussian output distributions. We implement and characterize the measurements needed to detect these attacks, and evaluate experimentally the information rates available to the legitimate users and the eavesdropper. The results are consistent with the optimality of Gaussian attacks resulting from the security proofs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

John Homer; Ashok Varikuti; Xinming Ou

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 ofmore » 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.« less

On resilience studies of system detection and recovery techniques against stealthy insider attacks

NASA Astrophysics Data System (ADS)

Wei, Sixiao; Zhang, Hanlin; Chen, Genshe; Shen, Dan; Yu, Wei; Pham, Khanh D.; Blasch, Erik P.; Cruz, Jose B.

2016-05-01

With the explosive growth of network technologies, insider attacks have become a major concern to business operations that largely rely on computer networks. To better detect insider attacks that marginally manipulate network traffic over time, and to recover the system from attacks, in this paper we implement a temporal-based detection scheme using the sequential hypothesis testing technique. Two hypothetical states are considered: the null hypothesis that the collected information is from benign historical traffic and the alternative hypothesis that the network is under attack. The objective of such a detection scheme is to recognize the change within the shortest time by comparing the two defined hypotheses. In addition, once the attack is detected, a server migration-based system recovery scheme can be triggered to recover the system to the state prior to the attack. To understand mitigation of insider attacks, a multi-functional web display of the detection analysis was developed for real-time analytic. Experiments using real-world traffic traces evaluate the effectiveness of Detection System and Recovery (DeSyAR) scheme. The evaluation data validates the detection scheme based on sequential hypothesis testing and the server migration-based system recovery scheme can perform well in effectively detecting insider attacks and recovering the system under attack.

Impact of Tumarkin attacks on complaints and work ability in Ménière's disease.

PubMed

Pyykkö, Ilmari; Manchaiah, Vinaya; Zou, Jing; Levo, Hilla; Kentala, Erna

2018-05-22

The purpose of the present study was to characterize the occurrence of Tumarkin attacks in patients with Ménière'sdisease (MD), and to study its association with reported complaints, severity of consequences, and also self-reported work ability. The study used a cross-sectional design. Data obtained from the Finnish Ménière Federation using an electronic survey was analyzed. 602 people with MD responded to the survey (62% response rate) with a mean age of 56.7 years and a mean duration of the disease 12.4 years. 49% of the respondents experienced Tumarkin attacks, which lasted for a few seconds to a few minutes. There were significant differences in complaints reported by MD patients with and without Tumarkin attacks. Respondents with Tumarkin attacks experienced various consequences, including tripping, falls, fear, anxiety, problems in dyadic life, and even transient loss of consciousness. Respondents with Tumarkin attacks had more frequently applied for pension than those not having Tumarkin attacks. On an average, respondents with Tumarkin attacks had less self-reported working ability when compared to those without Tumarkin attacks. The current study results suggest various differences in terms of complaints reported, severity of consequences, and the self-reported working ability in MD patients with and without Tumarkin attacks. Hearing healthcare professionals must examine Tumarkin attacks and their consequences in patients with MD during clinical examinations. In addition, the therapy should focus on alleviating the consequences and improving work ability.

Netwar

NASA Astrophysics Data System (ADS)

Keen, Arthur A.

2006-04-01

This paper describes technology being developed at 21st Century Technologies to automate Computer Network Operations (CNO). CNO refers to DoD activities related to Attacking and Defending Computer Networks (CNA & CND). Next generation cyber threats are emerging in the form of powerful Internet services and tools that automate intelligence gathering, planning, testing, and surveillance. We will focus on "Search-Engine Hacks", queries that can retrieve lists of router/switch/server passwords, control panels, accessible cameras, software keys, VPN connection files, and vulnerable web applications. Examples include "Titan Rain" attacks against DoD facilities and the Santy worm, which identifies vulnerable sites by searching Google for URLs containing application-specific strings. This trend will result in increasingly sophisticated and automated intelligence-driven cyber attacks coordinated across multiple domains that are difficult to defeat or even understand with current technology. One traditional method of CNO relies on surveillance detection as an attack predictor. Unfortunately, surveillance detection is difficult because attackers can perform search engine-driven surveillance such as with Google Hacks, and avoid touching the target site. Therefore, attack observables represent only about 5% of the attacker's total attack time, and are inadequate to provide warning. In order to predict attacks and defend against them, CNO must also employ more sophisticated techniques and work to understand the attacker's Motives, Means and Opportunities (MMO). CNO must use automated reconnaissance tools, such as Google, to identify information vulnerabilities, and then utilize Internet tools to observe the intelligence gathering, planning, testing, and collaboration activities that represent 95% of the attacker's effort.

Securing internet by eliminating DDOS attacks

NASA Astrophysics Data System (ADS)

Niranchana, R.; Gayathri Devi, N.; Santhi, H.; Gayathri, P.

2017-11-01

The major threat caused to the authorised usage of Internet is Distributed Denial of Service attack. The mechanisms used to prevent the DDoS attacks are said to overcome the attack’s ability in spoofing the IP packets source addresses. By utilising Internet Protocol spoofing, the attackers cause a consequential load over the networks destination for policing attack packets. To overcome the IP Spoofing level on the Internet, We propose an Inter domain Packet Filter (IPF) architecture. The proposed scheme is not based on global routing information. The packets with reliable source addresses are not rejected, the IPF frame work works in such a manner. The spoofing capability of attackers is confined by IPF, and also the filter identifies the source of an attack packet by minimal number of candidate network.

Monitoring the Attack Incidences and Damage Caused by the Almond Bark Beetle, Scolytus amygdali, in Almond Orchards

PubMed Central

Cuthbertson, Andrew G. S.; Braham, Mohamed

2018-01-01

The almond bark beetle, Scolytus amygdali Geurin-Meneville, is responsible for significant loss of fruit production in almond orchards throughout the world. Here, we studied the damage and the incidences of S. amygdali attack on two different scales: (1) at the level of a single tree; and (2) in an entire orchard. Our results revealed no differences in attack level among four orientations (east, west, south and north sides) for the whole tree. However, the bark that was facing west side in the direction of the prevailing wind was found to be the most suitable for females to initiate attack in Stratum S2. Attack distribution remains the same among different strata (strata is vertical divisions of the tree from the ground to the uppermost twigs with ~40 cm intervals). More than 50% of attack was observed in the trunk of the tree and upper strata. However, multiplication rate (number of emerged adults/maternal gallery) varies significantly between strata. In addition, we studied attack intensity (holes produced by beetle per tree) comparing it to tree morphology (flowers, leaves and circumferences) and gum deposit. Our results revealed a positive correlation between attack intensity and gum deposits, and a negative correlation between attack intensity and tree morphology. This revealed that gum on the tree was an indicator for attack intensity. A positive correlation between attack intensity and the circumference of the tree revealed that older trees were more susceptible to S. amygdali attack. These results, while preliminary, aim to help in the monitoring of S. amygdali populations before deciding to apply any control measures. PMID:29301271

On the IDAGAM I Combat Model.

DTIC Science & Technology

1977-06-01

defense missions in locations between the FEBA and the attackers’ targets; b) AAA can attack only aircraft attacking the guns them- selves or the targets...the guns are defending; c) SAM weapon systems can attack not only aircraft attack- ing them and the targets they defend but also, although possibly...Corporation), P.E. Louer (Department of the Army) and B.R. McEnany (Joint Chiefs of Staff/Studies, Analysis and Gaming Agency) for their help- ful

Terror attacks influence driving behavior in Israel

PubMed Central

Stecklov, Guy; Goldstein, Joshua R.

2004-01-01

Terror attacks in Israel produce a temporary lull in light accidents followed by a 35% spike in fatal accidents on Israeli roads 3 days after the attack. Our results are based on time-series analysis of Israeli traffic flows, accidents, and terror attacks from January 2001 through June 2002. Whereas prior studies have focused on subjective reports of posttraumatic stress, our study shows a population-level behavioral response to violent terror attacks. PMID:15448203

Childhood Internalizing and Externalizing Problems Predict the Onset of Clinical Panic Attacks over Adolescence: The TRAILS Study

PubMed Central

Mathyssek, Christina M.; Olino, Thomas M.; Verhulst, Frank C.; van Oort, Floor V. A.

2012-01-01

Background Panic attacks are a source of individual suffering and are an independent risk factor for later psychopathology. However, much less is known about risk factors for the development of panic attacks, particularly during adolescence when the incidence of panic attacks increases dramatically. We examined whether internalizing and externalizing problems in childhood predict the onset of panic attacks in adolescence. Method This study is part of the TRacking Adolescents’ Individual Lives Survey (TRAILS), a Dutch longitudinal population cohort study (N = 1,584). Internalizing and Externalizing Problems were collected using the Youth Self-Report (YSR) and the parent-report Child Behavior Checklist (CBCL) at baseline (age 10–12). At age 18–20, DSM-IV defined panic attacks since baseline were assessed with the Composite International Diagnostic Interview (CIDI). We investigated whether early adolescent Internalizing and Externalizing Problems predicted panic attacks between ages 10–20 years, using survival analysis in univariate and multivariate models. Results There were N = 314 (19.8%) cases who experienced at least one DSM-IV defined panic attack during adolescence and N = 18 (1.2%) who developed panic disorder during adolescence. In univariate analyses, CBCL Total Problems, Internalizing Problems and three of the eight syndrome scales predicted panic attack onset, while on the YSR all broad-band problem scales and each narrow-band syndrome scale predicted panic attack onset. In multivariate analyses, CBCL Social Problems (HR 1.19, p<.05), and YSR Thought Problems (HR 1.15, p<.05) and Social Problems (HR 1.26, p<.01) predicted panic attack onset. Conclusion Risk indicators of panic attack include the wide range of internalizing and externalizing problems. Yet, when adjusted for co-occurring problem behaviors, Social Problems were the most consistent risk factor for panic attack onsets in adolescence. PMID:23251576

Effectiveness of icatibant for treatment of hereditary angioedema attacks is not affected by body weight: findings from the Icatibant Outcome Survey, a cohort observational study.

PubMed

Caballero, Teresa; Zanichelli, Andrea; Aberer, Werner; Maurer, Marcus; Longhurst, Hilary J; Bouillet, Laurence; Andresen, Irmgard

2018-01-01

Icatibant is a bradykinin B2-receptor antagonist used for the treatment of hereditary angioedema attacks resulting from C1-inhibitor deficiency. Treatment is not adjusted by body weight however the impact of body mass index (BMI) on the effectiveness of icatibant is not documented in the literature. We examined disease characteristics and icatibant treatment effectiveness in patients stratified by BMI in the Icatibant Outcome Survey, an ongoing, international, observational study monitoring the real-world safety and effectiveness of icatibant. Attack and treatment characteristics as well as outcomes following treatment with icatibant were compared among patients with underweight, normal, overweight, and obese BMI. Data from 2697 icatibant-treated attacks in 342 patients (3.5, 44.7, 34.8, and 17.0% patients of underweight, normal, overweight, and obese BMI, respectively) were analyzed. There was no significant difference in the frequency and severity of attacks across BMI groups, although obese patients tended to have more attacks of high severity. There was no impact of BMI on the frequency of laryngeal attacks, but patients with normal BMI had fewer cutaneous attacks and more abdominal attacks. Most attacks (71.9-83.8%) were treated with a single icatibant injection without the need for rescue with plasma-derived C1-inhibitor (pdC1-INH), regardless of BMI. Patients with obese BMI used pdC1-INH as rescue treatment more often (P < 0.0001; P = 0.0232 excluding 2 outliers) and treated attacks earlier than patients with normal BMI (P = 0.007). Furthermore, time to resolution and duration of attack were shorter for patients with high BMI (P < 0.001 for overweight and P < 0.05 for obese versus normal). Overall, icatibant was comparatively effective in treating attacks in patients across all BMI groups. Trial registration NCT01034969.

Unique Regulation of the DosR Regulon in the Beijing Lineage of Mycobacterium tuberculosis.

PubMed

Domenech, Pilar; Zou, Jason; Averback, Alexandra; Syed, Nishath; Curtis, Daniele; Donato, Samuel; Reed, Michael B

2017-01-15

The DosR regulon, a set of 48 genes normally expressed in Mycobacterium tuberculosis under conditions that inhibit aerobic respiration, is controlled via the DosR-DosS/DosT two-component system. While the regulon requires induction in most M. tuberculosis isolates, for members of the Beijing lineage, its expression is uncoupled from the need for signaling. In our attempts to understand the mechanistic basis for this uncoupling in the Beijing background, we previously reported the identification of two synonymous single-nucleotide polymorphisms (SNPs) within the adjacent Rv3134c gene. In the present study, we have interrogated the impact of these SNPs on dosR expression in wild-type strains, as well as a range of dosR-dosS-dosT mutants, for both Beijing and non-Beijing M. tuberculosis backgrounds. In this manner, we have unequivocally determined that the C601T dosR promoter SNP is the sole requirement for the dramatic shift in the pattern of DosR regulon expression seen in this globally important lineage. Interestingly, we also show that DosT is completely nonfunctional within these strains. Thus, a complex series of evolutionary steps has led to the present-day Beijing DosR phenotype that, in turn, potentially confers a fitness advantage in the face of some form of host-associated selective pressure. Mycobacterium tuberculosis strains of the Beijing lineage have been described as being of enhanced virulence compared to other lineages, and in certain regions, they are associated with the dramatic spread of multidrug-resistant tuberculosis (TB). In terms of trying to understand the functional basis for these broad epidemiological phenomena, it is interesting that, in contrast to the other major lineages, the Beijing strains all constitutively overexpress members of the DosR regulon. Here, we identify the mutational events that led to the evolution of this unique phenotype. In addition, our work highlights the fact that important phenotypic differences exist between distinct M. tuberculosis lineages, with the potential to impact the efficacy of diagnosis, vaccination, and treatment programs. Copyright © 2016 American Society for Microbiology.

Somatic panic-attack equivalents in a community sample of Rwandan widows who survived the 1994 genocide

PubMed Central

Hagengimana, Athanase; Hinton, Devon; Bird, Bruce; Pollack, Mark; Pitman, Roger K.

2009-01-01

The present study is the first to attempt to determine rates of panic attacks, especially ‘somatically focused’ panic attacks, panic disorder, symptoms of post-traumatic stress disorder (PTSD), and depression levels in a population of Rwandans traumatized by the 1994 genocide. The following measures were utilized: the Rwandan Panic-Disorder Survey (RPDS); the Beck Depression Inventory (BDI); the Harvard Trauma Questionnaire (HTQ); and the PTSD Checklist (PCL). Forty of 100 Rwandan widows suffered somatically focused panic attacks during the previous 4 weeks. Thirty-five (87%) of those having panic attacks suffered panic disorder, making the rate of panic disorder for the entire sample 35%. Rwandan widows with panic attacks had greater psychopathology on all measures. Somatically focused panic-attack subtypes seem to constitute a key response to trauma in the Rwandan population. Future studies of traumatized non-Western populations should carefully assess not only somatoform disorder but also somatically focused panic attacks. PMID:12581815

Sub-threshold panic attacks and agoraphobic avoidance increase comorbidity of mental disorders: results from an adult general population sample.

PubMed

Pané-Farré, Christiane A; Fenske, Kristin; Stender, Jan P; Meyer, Christian; John, Ulrich; Rumpf, Hans-Jürgen; Hapke, Ulfert; Hamm, Alfons O

2013-06-01

Full-blown panic attacks are frequently associated with other mental disorders. Most comorbidity analyses did not discriminate between isolated panic attacks vs. panic attacks that occurred in the context of a panic disorder and rarely evaluated the impact of comorbid agoraphobia. Moreover, there are no larger scale epidemiological studies regarding the influence of sub-threshold panic attacks. 4075 German-speaking respondents aged 18-64 were interviewed using the fully structured Munich Composite International Diagnostic Interview. Limited symptom attacks, isolated panic attacks, and panic disorder were associated with other lifetime DSM-IV disorders with monotonically increasing odds and increasing tendency for multiple comorbidities across the three groups. The presence of agoraphobia was associated with more frequent comorbidity in all panic subgroups and also in persons who never experienced panic attacks. The present study suggests that populations with isolated or limited symptom should be carefully attended to in clinical practice, especially if agoraphobia is present. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of Scientific Calipers and Computer-Enabled CT Review for the Measurement of Skull Base and Craniomaxillofacial Dimensions

PubMed Central

Citardi, Martin J.; Herrmann, Brian; Hollenbeak, Chris S.; Stack, Brendan C.; Cooper, Margaret; Bucholz, Richard D.

2001-01-01

Traditionally, cadaveric studies and plain-film cephalometrics provided information about craniomaxillofacial proportions and measurements; however, advances in computer technology now permit software-based review of computed tomography (CT)-based models. Distances between standardized anatomic points were measured on five dried human skulls with standard scientific calipers (Geneva Gauge, Albany, NY) and through computer workstation (StealthStation 2.6.4, Medtronic Surgical Navigation Technology, Louisville, CO) review of corresponding CT scans. Differences in measurements between the caliper and CT model were not statistically significant for each parameter. Measurements obtained by computer workstation CT review of the cranial skull base are an accurate representation of actual bony anatomy. Such information has important implications for surgical planning and clinical research. ImagesFigure 1Figure 2Figure 3 PMID:17167599

Global Health Warning: Definitions Wield Power Comment on "Navigating Between Stealth Advocacy and Unconscious Dogmatism: The Challenge of Researching the Norms, Politics and Power of Global Health".

PubMed

Marten, Robert

2015-12-25

Gorik Ooms recently made a strong case for considering the centrality of normative premises to analyzing and understanding the underappreciated importance of the nexus of politics, power and process in global health. This critical commentary raises serious questions for the practice and study of global health and global health governance. First and foremost, this commentary underlines the importance of the question of what is global health, and why as well as how does this definition matter? This refocuses discussion on the importance of definitions and how they wield power. It also re-affirms the necessity of a deeper analysis and understanding of power and how it affects and shapes the practice of global health. © 2016 by Kerman University of Medical Sciences.

Sneaky light stop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eifert, Till; Nachman, Benjamin

2015-02-20

A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the standard model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Duemore » to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.« less

Sneaky light stop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eifert, Till; Nachman, Benjamin

2015-04-01

A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the standard model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Duemore » to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.« less

Parametric bicubic spline and CAD tools for complex targets shape modelling in physical optics radar cross section prediction

NASA Astrophysics Data System (ADS)

Delogu, A.; Furini, F.

1991-09-01

Increasing interest in radar cross section (RCS) reduction is placing new demands on theoretical, computation, and graphic techniques for calculating scattering properties of complex targets. In particular, computer codes capable of predicting the RCS of an entire aircraft at high frequency and of achieving RCS control with modest structural changes, are becoming of paramount importance in stealth design. A computer code, evaluating the RCS of arbitrary shaped metallic objects that are computer aided design (CAD) generated, and its validation with measurements carried out using ALENIA RCS test facilities are presented. The code, based on the physical optics method, is characterized by an efficient integration algorithm with error control, in order to contain the computer time within acceptable limits, and by an accurate parametric representation of the target surface in terms of bicubic splines.

Guerilla Science: Mixing Science with Art, Music and Play

NASA Astrophysics Data System (ADS)

Rosin, Mark; Koski, Olivia; Science, Guerilla

2013-01-01

Guerilla Science is an international organization at the boundaries of adult/teen science education and live entertainment. Dedicated to science by stealth we mix science with art, music and play in unconventional environments like music festivals, art galleries, banquets, department stores and theaters. Over the last five years, Guerilla Science has impacted over 11 thousand members of the public and worked with more than one hundred science-partners. Findings from three external evaluations confirm that these events have been successful, and Guerilla Science has been featured in international media including Wired, Scientific American, Getty Images, and the BBC. In this presentation, the US director, Mark Rosin, will discuss Guerilla Science's astronomical outreach efforts, including events like the Intergalactic Travel Bureau, Extra-Terrestrial Broadcasting, and Sex on other Planets. He will also discuss how to get involved with the project.

Dual-band wide-angle metamaterial perfect absorber based on the combination of localized surface plasmon resonance and Helmholtz resonance.

PubMed

Zhang, Changlei; Huang, Cheng; Pu, Mingbo; Song, Jiakun; Zhao, Zeyu; Wu, Xiaoyu; Luo, Xiangang

2017-07-18

In this article, a dual-band wide-angle metamaterial perfect absorber is proposed to achieve absorption at the wavelength where laser radar operates. It is composed of gold ring array and a Helmholtz resonance cavity spaced by a Si dielectric layer. Numerical simulation results reveal that the designed absorber displays two absorption peaks at the target wavelength of 10.6 μm and 1.064 μm with the large frequency ratio and near-unity absorptivity under the normal incidence. The wide-angle absorbing property and the polarization-insensitive feature are also demonstrated. Localized surface plasmons resonance and Helmholtz resonance are introduced to analyze and interpret the absorbing mechanism. The designed perfect absorber can be developed for potential applications in infrared stealth field.