8,237 research outputs found
When Terrorism Threatens Health: How Far are Limitations on Personal and Ecomonic Liberties Justified
The government is engaged in a homeland-security project to safeguard the population\u27s health from potential terrorist attacks. This project is politically charged because it affords the state enhanced powers to restrict personal and economic liberties. Just as governmental powers relating to intelligence, law enforcement, and criminal justice curtail individual interests, so too do public health powers
Putative ligand binding sites of two functionally characterized bark beetle odorant receptors
Background: Bark beetles are major pests of conifer forests, and their behavior is primarily mediated via olfaction. Targeting the odorant receptors (ORs) may thus provide avenues towards improved pest control. Such an approach requires information on the function of ORs and their interactions with ligands, which is also essential for understanding the functional evolution of these receptors. Hence, we aimed to identify a high-quality complement of ORs from the destructive spruce bark beetle Ips typographus (Coleoptera, Curculionidae, Scolytinae) and analyze their antennal expression and phylogenetic relationships with ORs from other beetles. Using 68 biologically relevant test compounds, we next aimed to functionally characterize ecologically important ORs, using two systems for heterologous expression. Our final aim was to gain insight into the ligand-OR interaction of the functionally characterized ORs, using a combination of computational and experimental methods. Results: We annotated 73 ORs from an antennal transcriptome of I. typographus and report the functional characterization of two ORs (ItypOR46 and ItypOR49), which are responsive to single enantiomers of the common bark beetle pheromone compounds ipsenol and ipsdienol, respectively. Their responses and antennal expression correlate with the specificities, localizations, and/or abundances of olfactory sensory neurons detecting these enantiomers. We use homology modeling and molecular docking to predict their binding sites. Our models reveal a likely binding cleft lined with residues that previously have been shown to affect the responses of insect ORs. Within this cleft, the active ligands are predicted to specifically interact with residues Tyr84 and Thr205 in ItypOR46. The suggested importance of these residues in the activation by ipsenol is experimentally supported through site-directed mutagenesis and functional testing, and hydrogen bonding appears key in pheromone binding. Conclusions: The emerging insight into ligand binding in the two characterized ItypORs has a general importance for our understanding of the molecular and functional evolution of the insect OR gene family. Due to the ecological importance of the characterized receptors and widespread use of ipsenol and ipsdienol in bark beetle chemical communication, these ORs should be evaluated for their potential use in pest control and biosensors to detect bark beetle infestations
Simulated Anthrax Attacks and Syndromic Surveillance
Bioterrorism surveillance systems can be assessed using modeling to simulate real-world attacks
Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options
Producción CientÃficaPine pitch canker (PPC), caused by the pathogenic fungus Fusarium circinatum (Nirenberg
and O’ Donnell), is a serious threat to pine forests globally. The recent introduction of the pathogen to Southern Europe and its spread in Mediterranean region is alarming considering the immense
ecological and economic importance of pines in the region. Pines in forests and nurseries can be
infected, resulting in severe growth losses and mortality. The pathogen is known to spread in plants
for planting and in seeds, and results from recent studies have indicated that F. circinatum may also
spread through phoretic associations with certain insects. With this review, we aim to expand the
current understanding of the risk of insect-mediated spread of PPC in different parts of Europe.
Through the joint action of a multinational researcher team, we collate the existing information about
the insect species spectrum in different biogeographic conditions and scrutinize the potential of
these insects to transmit F. circinatum spores in forests and nurseries. We also discuss the impact of
environmental factors and forest management in this context. We present evidence for the existence of
a high diversity of insects with potential to weaken pines and disseminate PPC in Europe, including
several common beetle species. In many parts of Europe, temperatures are projected to rise, which
may promote the activity of several insect species, supporting multivoltinism and thus, further
amplifying the risk of insect-mediated dissemination of PPC. Integrated pest management (IPM)
solutions that comply with forest management practices need to be developed to reduce this risk.
We recommend careful monitoring of insect populations as the basis for successful IPM. Improved
understanding of environmental control of the interaction between insects, the pathogen, and host
trees is needed in order to support development of bio-rational strategies to safeguard European pine
trees and forests against F. circinatum in future.European Cooperation in Science and Technology (COST Action FP1406 PINESTRENGTH)Ministerio de EconomÃa, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R)Portuguese Foundation for Science and Technology (contract IF/00471/2013/CP1203/CT0001)Russian Foundation for Basic Research (grant 17-04-01486)Saint Petersburg State Polytechnical University (project 2019-0420
OnionBots: Subverting Privacy Infrastructure for Cyber Attacks
Over the last decade botnets survived by adopting a sequence of increasingly
sophisticated strategies to evade detection and take overs, and to monetize
their infrastructure. At the same time, the success of privacy infrastructures
such as Tor opened the door to illegal activities, including botnets,
ransomware, and a marketplace for drugs and contraband. We contend that the
next waves of botnets will extensively subvert privacy infrastructure and
cryptographic mechanisms. In this work we propose to preemptively investigate
the design and mitigation of such botnets. We first, introduce OnionBots, what
we believe will be the next generation of resilient, stealthy botnets.
OnionBots use privacy infrastructures for cyber attacks by completely
decoupling their operation from the infected host IP address and by carrying
traffic that does not leak information about its source, destination, and
nature. Such bots live symbiotically within the privacy infrastructures to
evade detection, measurement, scale estimation, observation, and in general all
IP-based current mitigation techniques. Furthermore, we show that with an
adequate self-healing network maintenance scheme, that is simple to implement,
OnionBots achieve a low diameter and a low degree and are robust to
partitioning under node deletions. We developed a mitigation technique, called
SOAP, that neutralizes the nodes of the basic OnionBots. We also outline and
discuss a set of techniques that can enable subsequent waves of Super
OnionBots. In light of the potential of such botnets, we believe that the
research community should proactively develop detection and mitigation methods
to thwart OnionBots, potentially making adjustments to privacy infrastructure.Comment: 12 pages, 8 figure
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