Moment Of Attack Research Articles

Bipartite Flocking for Cucker-Smale Model on Cooperation-Competition Networks Subject to Denial-of-Service Attacks

This work emphasises the bipartite flocking of leader-follower Cucker-Smale model on cooperation-competition networks under Denial-of-Service (DoS) attacks. The DoS with limited energy is the periodic signal that consists of active periods and asleep periods. It interruptes the information interactions among agents during the activation stages, while it concentrates on storing own energy for the next attack moment during the asleep stages. Meanwhile, the control strategy to defend against DoS attacks is established. The products convergence of infinite sub-stochastic matrices method is employed to implement the bipartite flocking behavior. Based on this method, a algebraic condition which is related to initial states, the topological structure and the weight function is constructed. Moreover, the obtained theoretical results are demonstrated by numerical simulations.

Анализ момента времени совершения ближайшей злоумышленной атаки в системе информационной безопасности на основе аппарата редких регенерирующих процессов

The paper analyzes the model that describes the process of attacking the protected object, where closed information is stored, the model built on the basis of the apparatus of regenerating sequences of the successful completion of malicious attacks. The moments of the attacks are considered in detail. It is assumed that attacks originating from a single source are rare enough, have an isolated singled character and are quite distant in time, that is, the event of a successful attack is a rare event, but the losses upon its successful completion can be huge. For the studied characteristic there is chosen a nearest moment when the next attack is successful: this characteristic is very important with relation to the information security. Knowing the parameters of this characteristic will help, at appropriate time intervals, to take additional actions that increase the level of protection. Studies are conducted under the assumption that all characteristics of the model are heterogeneous, which more adequately corresponds to the real state in information security systems. There has been obtained an asymptotic relation for the moment of the next successful malicious attack under conditions when the time interval for analyzing the attack is constantly rising and the probability of attack is becoming less common, both values changing consistently.

Sign systems: The dawn of earliest mankind

Abstract The early Pleistocene hunt scene was instant: when an antelope jerked in the water edge, the first “drivers” of the hunt were already in motion; the moment of outburst after a long ambush lasted less than second. The sudden hunt movements were typical of every prey-abundant landscape since even earlier geological periods. The analysis of Laetoli footprints made by our evolutionary ancestors more than three millions years ago indicates that in a randomly chosen moment, the landscape was full of animals of different species. The language used in the attack moment has to be agitative, only vowels in clausure between two consonants. During the process of further development, those consonants became more and more similar to delimitators, the borders where intrasemiotic realities translate extrasemiotic environment. Speech is an old Paleolithic tool for directing hunters to the useful positions. It was rather an instrument of a leader than grooming “clicks” of kin’s females.

Larval aggregation in a Neotropical butterfly: risky behaviors, per capita risk, and larval responses in Ascia monuste orseis

Gregariousness in insects has been shown to improve performance, feeding, and defense against predation. Nevertheless, an increased risk of antagonistic interactions such as competition and predation occurs in group living. We examined the effects of both group size and larval age of aggregations of the butterfly Ascia monuste orseis (Godart, 1819) on larval permanency and attack by natural enemies. Group behavior was also investigated with respect to predation risk, as well as larval responses after enemy attack. One larva and groups of 10 and 50 larvae were assigned on host plants and monitored daily to evaluate larval permanency. At each instar, a subset of groups was observed for a 4-h period to identify natural enemies and to record both group behaviors performed at the moment of attack and responses to the attacks. Permanency on the host was higher in aggregations than in solitary larvae. Larger aggregations conferred greater protection to A. monuste orseis larvae against natural enemies than did smaller aggregations, through lower per capita predation. Parasitoidism was more intense in small-sized larvae, whereas late instars were more susceptible to predators. Similarly to solitary species, larvae were most susceptible to attacks when performing searching and feeding compared to resting and moving. Moving away and headrearing were observed for all instars and groups after enemy attacks and rarely protected larvae against natural enemies. Our results show that behaviors that involve head movements posed more attack risks than those that involve moving the whole body or absence of movements, and that larval aggregation in A. monuste orseis rarely exhibits defensive behaviors against natural enemies. Larval defense is provided through dilution effect. Natural enemies can use several cues to find their prey, as for example, prey morphology, chemistry, and behavior. Nevertheless, group behavior has been poorly investigated with respect to mortality risks in phytophagous insects. This study investigated whether certain group sizes and behaviors are more risky than others in the gregarious Ascia monuste larvae. Larvae were susceptible to both parasitoids and predators, and larger groups conferred more protection against natural enemies than smaller ones. Similarly to species with a solitary habit, behaviors that involved head movements as searching and feeding posed more attack risks than moving and resting. Defense behaviors were not very effective against natural enemies. Our study reveals that both solitary and gregarious species may share more similarities in terms of susceptibility to natural enemies than previously thought.

Post-attack Aposematic Display in Prey Facilitates Predator Avoidance Learning

Warning signals protect unpalatable prey from predation because predators who learn the association between the warning signal and prey unprofitability decrease attacks on the prey. Most of the research have focused on visual aposematic signals that are constantly presented and visible to the predators. But a variety of chemically defended insects are rather cryptic when resting, and only in response to predator attacks (post-attack) they perform displays of conspicuous abdomens or hindwings normally hidden under forewings. The function of those displays in unpalatable insects is not well understood. We examined two adaptive hypotheses on this facultative aposematic display using wild-caught oriental tits (Parus minor) as predators. First, we tested whether the display increases the rejection of the prey by predators upon seeing the display (i.e. at the moment of attack) through learning trials (aposematic signaling hypothesis). Second, we tested whether the display facilitates the memory formation between cryptic visible form of the prey and prey defense so that it prevents the predators initiate an attack upon seeing the cryptic form (facilitation hypothesis). We found that predators learned to avoid attacking the prey which supports the facilitation hypothesis. However, the support for the aposematic signaling hypothesis was equivocal. Our results open new directions of research by highlighting the possibility that similar facilitation effects may contribute to the evolution of various forms of post-attack visual displays in chemically, or otherwise, defended animals.

Clinical and angiographic characteristics of young adult patients recovered from acute myocardial infarction

Introduction. Occurrence of acute myocardial infarction in young adults is a relatively rare. In majority of the studies, age of 45 years is used as cut-off line in definition of the young patients with coronary artery disease or myocardial infarction. Studies have shown that younger population aged less than 40 years represents only 2-8% of all patients with myocardial infarction. Objective. The aim of this study was to examine the specificities of clinical and angiographic characteristics of the patients recovered from acute myocardial infarction, younger than 45 years at the moment of attack, by comparing their clinical and angiographic characteristics with those of patients older than 65 years, who recovered from acute myocardial infarction. Method. The study included 78 patients recovered from acute myocardial infarction, 33 patients were younger than 45 years (40.7 ± 3.9 years), 25 (75.7%) men and eight (24.2%) female, and 45 patients were older than 65 years (68.2 ± 4.2 years), 32 (71.3%) men and 13 women. Detailed history taking, physical examination, permanent ECG monitoring, laboratory analyses, X-ray examination, echocardiography and selective coronarography of all patients were performed. Results. Patients younger than 45 years had a significantly higher incidence of STEMI (p <0.01), lower infarction (p<0.01) and diaphragmatic infarction (p <0.01) compared to patients older than 65 years, and patients older than 65 years had anterior infarction more frequent (p<0.01). Three vessel coronary disease had 18.2% of patients younger than 45 and 57.8% older than 65 years (p<0.01), two vessel disease had 36.4% vs. 20.0% (p <0.05) and one vessel disease had 36.4% vs. 20.0% (p>0.05) Multivessel disease existed at 54.5% under the age of 45 and 77.8% older than 65 years (p<0.05). Among patients with one vessel coronary disease. Stenosis of LAD was found in 63.6% of patients under 45 years, and in 84.4% of patients over 65 years (p<0.05), stenosis of RCX in 39.4% vs. 62.2% (p<0.05) and stenosis of RCA in 57.6% vs. 68.9% (p>0.05). The disease of left main coronary artery had 6.1% of patients younger than 45 and 22.2% of patients older than 65 years (p<0.05). 9.1% of patients younger than 45 and 2.2% of patients older than 65 years (p>0.05) Were without significant coronary artery stenosis Comparing risk factors for coronary artery disease in patients younger than 45 years and older than 65 years, we find: hypertension in 48.5% vs. 88.9% (p<0.01), hyperlipidemia in 69.69% vs. 71.1% (p>0.05), diabetes mellitus in 21.2% vs. 55.5% (p <0.01), smoking in 72.7% vs. 33.3% (p<0.01), obesity in 33.3% vs. 33.3% (p>0.05), and stress in 18.2% vs. 2.2% (p <0.01). Conclusion. Patients with myocardial infarction younger than 45 years are predominantly male and have a significantly higher incidence of infarction with ST segment elevation (STEMI), lower and diaphragmatic localization of infarction, significantly higher prevalence of smoking habits, hypertriglyceridemia and stress, as well as significantly lower incidence of three-vessel and multivessel disease and stenosis of the left main coronary artery, compared to patients with myocardial infarction older than 65 years.

Effect of sex and bright coloration on survival and predator-induced wing damage in an aposematic lantern fly with startle display

1. Aposematic coloration in prey promotes its survival by conspicuously advertising unpalatability to predators. Although classical examples of aposematic signals involve constant presentation of a signal at a distance, some animals suddenly display warning colours only when they are attacked. 2. Characteristics of body parts suddenly displayed, such as conspicuous coloration or eyespot pattern, may increase the survival of the prey by startling the predator, and/or by signalling unpalatability to the predators at the moment of attack. 3. The adaptive value of such colour patterns suddenly displayed by unpalatable prey has not been studied. We experimentally blackened the red patch in the conspicuous red–white–black hindwing pattern displayed by an unpalatable insect Lycorma delicatula White (Hemiptera: Fulgoridae) in response to predator's attack. 4. There was no evidence that the presence of the red patch increased prey survival over several weeks. We hypothesise that predators generalised from the red–white–black patches on the hindwings of unpalatable L. delicatula to any similar wing display as a signal of unpalatability. Because a higher proportion of males than females stay put at their resting sites, displaying their wings in response to repeated attacks by predators, wing damage was more frequent in males than in females. 5. To our knowledge, this is the first experimental test of an adaptive role of aposematic signals presented by unpalatable prey during sudden displays triggered by direct predatory attack.

Reliving genocide: the work of Kurdish genocide victims in the Court of Justice

Introduction Victims play a crucial but ambivalent role in genocide trials: their testimony can contribute to the prosecution of indicted war criminals, but the price they pay is that of 'reliving' the genocide attack. As every detail could be crucial for sentencing war criminals, the victims must delve into difficult histories and answer confronting questions such as 'how were you attacked?', 'what injuries have you suffered?' and 'how was your family killed?' Victims can only answer these questions by metaphorically reliving the moment of attack. Speaking publicly about their late is a painful issue for victims, but it is also a way to give voice to the marginalised. This expands on the much-discussed theme of 'voicelessness' by marginalisation within cultural studies, and attempts to exit this situation. Works of, for example, Antonio Gramsci (1991), expand on the concept of cultural hegemony, or Jurgen Habermas' (1989) idea about the public sphere concerns the imposition of thinking, speaking and silence structures. Cultural studies partly has an interest in voicelessness, because it views this as a socio-political construction. According to Arthur Kleinman et al, the testimonies of the victims bring this structure to the surface, because they place the suffering in a social context: 'Social suffering results from what political, economic, and institutional power does to people, and reciprocally, from how these forms of power themselves influence responses to social problems' (1997: ix). Thus, 'social suffering' shows 'the interpersonal grounds of suffering: or in other words, that suffering is a social experience' (ibid.). And that is always the case with genocide: this atrocity requires a high degree of institutional organisation (think of the military), policies and economic activities (as will become clear in this article, the genocide charges are against a businessman). Victims bearing witness in court is therefore not only of a legal nature, it is a political act. As John Beverley states: 'It has to do with how people who are marginalised, repressed, and exploited [...] use something like testimonio for their purposes: that is, as a weapon, a way of fighting back. [...] To recall Marx's well-known distinction, testimonio aspires not only to interpret the world but also to change it' (2004: xvi). The withdrawal from the position of subordination was the case in the trial against Dutch businessman, Frans van Anraat, charged with providing assistance to the genocide committed by Saddam Hussein's regime in the Kurdish town of Halabja: (1) the victims, who were assisted by the Halabja Committee, and by reliving the genocide attack in court, contributed to the conviction of a major war criminal. (2) The lawsuit has cost the Halabja Committee's chairman, Amir Khadir, five years of his life: a year-and-a-half of preparations and then the trial itself (including the appeal). It was a psychologically draining process: hearing the witnesses, providing assistance to the victims and translating documents along with the painful recollection of circumstances in which family and friends were lost or injured. Amir Khadir recalled a victim who at the time of the attacks was three years of age. Now aged 25, only 30 per cent of his lung capacity remains; after taking just four steps up a flight of stairs, he is tired and needs to rest. Listening to the accounts of victims such as these was difficult for many in the courtroom; the recollections of one of the victims reduced the entire courtroom to tears, including the legal authorities. The terror that Khadir had to relive suggests that the 'people were the energy of the war' as be puts it: that it was the ordinary people (both citizens and soldiers at the lower levels) who were 'fed' to the war. The Halabja Committee has, therefore, not only testified for the Iraqi citizens, but also for the ordinary Iranian soldiers who were attacked with Iraqi poisonous gases. …

Synthesis and structure of ethylene oxide oligomers containing sulphonate groups

The new oligoethylene oxide derivatives containing sulphonate groups are synthesized from oligoester epoxides, and the structure of the products is studied by IR and 13C NMR spectroscopy. Addition of sulphite ion to the oxyrane ring of the polyethylene glycol involves the participation of the less substituted primary carbon atom of the ring. At the moment of attack on the reactive centre the sulphite ion is transformed into a sulphonite ion, which results in the formation of oligoethylene oxide sulphonate having a secondary terminal hydroxyl group.

The perceptual attack time of musical tones.

Perceptual attack time (PAT) is defined as the time a tone's moment of attack or most salient metrical feature is perceived relative to its physical onset. Experiments are described that measured the PATs of recorded orchestral instrument tones by means of an interactive procedure with a computer and digital music synthesizer. Some PAT prediction models were then developed and tested against the empirical data. The most successful model had a correlation of 0.995 between measured and predicted PATs. The PAT is dependent on both rise time and listening level, indicating that the slope of the rise function is a key factor. Duration and spectrum can also act as cues to PAT, but are much less influential than amplitude or intensity cues. Possible relations to findings in physiology, particularly to the phenomenon of short-term adaptation in the firing of auditory fibers, are discussed.

The effects of amphetamine on attack behavior in the cat

Summary Amphetamine was given intraperitoneally in doses of 5 mg and 10 mg to cats which had been chronically implanted with electrodes in the lateral hypothalamus and midbrain reticular formation. The attack on an anesthetized rat which could be elicited by electrical stimulation of the lateral hypothalamus was facilitated by amphetamine. The facilitation of this attack by simultaneous electrical stimulation of the midbrain reticular formation was further enhanced by amphetamine, provided that the combined stimulation did not exceed a certain level above the level the attack behavior was inhibited. The facilitation occurred between the onset of stimulation and the first translational movement and between the first movement and moment of attack. It is postulated that the action of amphetamine is similar to direct electrical stimulation of the midbrain reticular formation but with some differences occurring as a result of concomitant indirect actions.

Addition reactions of fluoroalkenes

1. Perfluoropropene, in presence of alkalis, readily unites with alcohols and thiols, and the hydrogen atom of the hydroxyl group of the alcohol or of the mercapto group of the thiol, in contrast to its behavior, in the case of propene, adds to the middle carbon atom of perfluoropropene. 2. The alkyl 2H-hexafluoropropyl ethers formed as a result of reaction of perfluoropropene with alcohols are readily hydrolyzed into esters of 2H-tetrafluoropropionic acid (proof of direction of addition). 3. The normal addition reaction, leading to formation of alkyl 2H-hexafluoropropyl ethers, is accompanied by the formation in appreciable amount of alkyl perfluoroallyl ethers (or alkyl perfluoroallyl sulfides in the case of reaction with thiols). 4. It has been established that the fluorine atoms of the trifluoromethyl group of perfluoropropene, unlike those in compounds carrying a trifluoromethyl group on an atom not linked to a neighbor by a multiple bond, have an appreciable degree of mobility. 5. The formation of perfluoroallyl derivatives in reactions of perfluoropropene with substances containing mobile hydrogen atoms (alcohols, thiols, etc.) cannot be regarded as a direct replacement of a fluorine atom of the trifluoromethyl group (by alkoxyl or alkylthio), but is the result of anionoid attack by a nucleophilic reagent on the extreme carbon atom of perfluoropropene having the least electron density; in the moment of attack, transposition of the double bond occurs, and one of the fluorine atoms of the trifluoromethyl group is removed as an anion.