Cooperative detection and protection against network attacks using decentralized information sharing

Network attacks, such as distributed denial of service (DDoS) and Internet worms, are highly distributed and well coordinated offensive assaults on services, hosts, and the infrastructure of the Internet, and can have disastrous effects including financial losses and disruption of essential services. Consequently, effective defensive countermeasures against these attacks must provide equally sophisticated and well coordinated mechanisms for monitoring, analysis, and response. In this paper, we investigate techniques for cooperative attack detection and countermeasures using decentralized information sharing. The key underlying idea is the use of epidemic algorithms to share attack information and achieve quasi-global knowledge about attack behaviors. This paper first presents a conceptual model that defines the relationships between the level of knowledge in the distributed system and the accuracy of attack detection. The design of a cooperative attack detection and defense framework is then presented, and its use for detecting and defending against DDoS attacks and Internet worms is described. Simulation results are presented to demonstrate the feasibility and effectiveness of the framework against these attacks.     

Distributed denial-of-service attacks against HTTP/2 services

HTTP/2 is the second major version of the HTTP protocol published by the internet engineering steering group. The protocol is designed to improve reliability and performance Such enhancements have thus delineated the protocol as being more vulnerable to distributed denial-of-service (DDoS) attacks when compared to its predecessor. Recent phenomenon showed that legitimate traffic or flash crowds could have high-traffic flow characteristics as seen in DDoS attacks. In this paper, we demonstrate that legitimate HTTP/2 flash crowd traffic can be launched to cause denial of service. To the best of our knowledge, no previous study has been conducted to analyse the effect of both DDoS as well as flash crowd traffic against HTTP/2 services. Results obtained prove the effect of such attacks when tested under four varying protocol-dependant attack scenarios.     

The alternative futures of naval force

Abstract

The paper discusses a series of new technologies and new strategic factors entering into naval power and their analytical consequences. The argument is made that (1) traditional ways of identifying “naval power”; no longer have any utility or carry real meaning; (2) current high‐value surface naval forces of declining utility are extremely vulnerable to attack, which will force a radical revaluation in the West of “sea control”; and the costs of such control; and (3) the Soviet Union, by virtue of its geography and its capacity to innovate in “sea denial”; naval force, may be better positioned that the West to take advantage of new antinaval technologies. Western countermeasures may be expensive, involve a radical restructuring of naval force, and mean the acceptance of permanent strategic vulnerability at sea. The “new era”; of naval politics cannot be divorced, analytically and operationally, from emergent space systems and from the strategic nuclear balance.     

Detecting network cyber-attacks using an integrated statistical approach

Cluster Computing - Anomaly detection in the Internet of Things (IoT) is imperative to improve its reliability and safety. Detecting denial of service (DOS) and distributed DOS (DDOS) is one of the...     

SSK-DDoS: distributed stream processing framework based classification system for DDoS attacks

Cluster Computing - Distributed denial of service (DDoS) is an immense threat for Internet based-applications and their resources. It immediately floods the victim system by transmitting a large...     

The effect of stimulus duration and motor response in hemispatial neglect during a visual search task

Patients with hemispatial neglect exhibit a myriad of profound deficits. A hallmark of this syndrome is the patients' absence of awareness of items located in their contralesional space. Many studies, however, have demonstrated that neglect patients exhibit some level of processing of these neglected items. It has been suggested that unconscious processing of neglected information may manifest as a fast denial. This theory of fast denial proposes that neglected stimuli are detected in the same way as non-neglected stimuli, but without overt awareness. We evaluated the fast denial theory by conducting two separate visual search task experiments, each differing by the duration of stimulus presentation. Specifically, in Experiment 1 each stimulus remained in the participants' visual field until a response was made. In Experiment 2 each stimulus was presented for only a brief duration. We further evaluated the fast denial theory by comparing verbal to motor task responses in each experiment. Overall, our results from both experiments and tasks showed no evidence for the presence of implicit knowledge of neglected stimuli. Instead, patients with neglect responded the same when they neglected stimuli as when they correctly reported stimulus absence. These findings thus cast doubt on the concept of the fast denial theory and its consequent implications for non-conscious processing. Importantly, our study demonstrated that the only behavior affected was during conscious detection of ipsilesional stimuli. Specifically, patients were slower to detect stimuli in Experiment 1 compared to Experiment 2, suggesting a duration effect occurred during conscious processing of information. Additionally, reaction time and accuracy were similar when reporting verbally versus motorically. These results provide new insights into the perceptual deficits associated with neglect and further support other work that falsifies the fast denial account of non-conscious processing in hemispatial visual neglect.     

Inner-city women and AIDS: The psycho-social benefits of unsafe sex

The paper describes and analyzes findings from a larger study of the links between low levels of condom use and impoverished, urban, African-American women's experiences and understandings of heterosexual relationships. The research identifies and explores psycho-social barriers to safer-sex. This article examines, in detail, HIV/AIDS risk denial and women's strategic use of unsafe (condomless) sex and monogamy narratives to build and to maintain this denial. The tendency to view urban African-American women's conjugal affiliations as instrumental is questioned.     

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

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.     

Children and the nuclear threat: a child psychiatrist's personal reflections

From the very first stages of life, parents have provided their children with love and protection against harm from within or without, especially from life-threatening situations. Children's perception of death as a unique phenomena develops around age ten and later on, when they begin to grasp the meaning of mortality. This often occurs when they themselves suffer from terminal illness. Children have been the object of destruction, as witnessed by The Holocaust and Hiroshima. The threat of nuclear war poses a new problem for parents, since threatening others is no longer a viable solution to the conflict. In addition, adults manifest a massive denial that the destruction of mankind can take place at any time. This denial, like a family secret, prevents children from asking questions and expressing to their parents their fears about their own and mankind's destruction. Examples are given of how children do express their concerns and fears about the nuclear threat when they are allowed to express themselves. Unless this denial is replaced by open communication about the seriousness of the situation, children and adolescents will view the adults' denial as numbness and folly and as responsible for the world's destruction. A meaningful dialogue between parents and children about the threat is given as the solution to the family conflict.     

Acceptability of Rapid Diagnostic Test-Based Management of Malaria among Caregivers of Under-Five Children in Rural Ghana

Introduction

WHO now recommends test-based management of malaria (TBMM) across all age-groups. This implies artemisinin-based combination treatment (ACT) should be restricted to rapid diagnostic test (RDT)-positive cases. This is a departure from what caregivers in rural communities have been used to for many years.

Methods

We conducted a survey among caregivers living close to 32 health centres in six districts in rural Ghana and used logistic regression to explore factors likely to influence caregiver acceptability of RDT based case management and concern about the denial of ACT on account of negative RDT results. Focus group discussions were conducted to explain the quantitative findings and to elicit further factors.

Results

A total of 3047 caregivers were interviewed. Nearly all (98%) reported a preference for TBMM over presumptive treatment. Caregivers who preferred TBMM were less likely to be concerned about the denial of ACT to their test-negative children (O.R. 0.57, 95%C.I. 0.33–0.98). Compared with caregivers who had never secured national health insurance cover, caregivers who had valid (adjusted O.R. 1.30, 95% CI 1.07–1.61) or expired (adjusted O.R. 1.38, 95% CI 1.12–1.73) insurance cover were more likely to be concerned about the denial of ACT to their RDT-negative children. Major factors that promote TBMM acceptability include the perception that a blood test at health centre level represents improvement in the quality of care, leads to improvement in treatment outcomes, and offers opportunity for better communication between health workers and caregivers. Acceptability is also enhanced by engaging caregivers in the procedures of the test. Apprehensions about negative health worker attitude could however undermine acceptance.

Conclusion

Test (RDT)-based management of malaria in under-five children is likely to be acceptable to caregivers in rural Ghana. The quality of caregiver-health worker interaction needs to be improved if acceptability is to be sustained.     

支气管哮喘急性发作期患者呼出气一氧化氮的诊断价值及与肺功能和血清ECP、IL-13的关系研究

摘要 目的：研究支气管哮喘（BA）急性发作期患者呼出气一氧化氮（FeNO）的诊断价值及与其肺功能和血清嗜酸性粒细胞阳离子蛋白（ECP）、白细胞介素-13（IL-13）的关系。方法：将我院从2018年1月～2020年1月收治的78例BA患者纳入研究,将其按照病情的不同分成急性发作组（急性发作期）42例与非急性发作组（缓解期）36例。比较两组FeNO、肺功能指标水平和血清ECP、IL-13水平,并作相关性分析。此外,以受试者工作特征（ROC）曲线分析FeNO对BA急性发作期的有关诊断效能。结果：急性发作组FeNO水平高于非急性发作组,而最大呼气流量占预计值的百分比（PEF%pred）、第1秒用力呼气末容积占预计值的百分比（FEV₁%pred）及用力肺活量占预计值的百分比（FVC%pred）水平均低于非急性发作组（均P＜0.05）。急性发作组血清ECP、IL-13水平均高于非急性发作组（均P＜0.05）。经Pearson相关分析发现：BA急性发作期患者FeNO与PEF%pred、FEV₁%pred、FVC%pred均呈负相关,而与血清ECP、IL-13水平均呈正相关（均P＜0.05）。经ROC曲线分析发现：FeNO诊断BA急性发作期的曲线下面积为0.818,敏感度与特异度分别为75.51%、94.05%。结论：BA急性发作期患者FeNO水平显著升高,且和肺功能、血清ECP、IL-13密切相关,检测FeNO对BA急性发作期患者具有较高的诊断价值。     

From high-availability to collapse: quantitative analysis of “Cloud-Droplet-Freezing” attack threats to virtual machine migration in cloud computing

Virtual machines (VM) migration can improve availability, manageability, performance and fault tolerance of systems. Current migration researches mainly focus on the promotion of the efficiency by using shared storage, priority-based policy etc.. But the effect of migration is not well concerned. In fact, once physical servers are overloaded from denial-of-service attack (DDoS) attack, a hasty migration operation not only unable to alleviate the harm of the attack, but also increases the harmfulness. In this paper, a novel DDoS attack, Cloud-Droplet-Freezing (CDF) attack, is described according to the characteristics of cloud computing cluster. Our experiments show that such attack is able to congest internal network communication of cloud server cluster, whilst consume resources of physical server. Base on the analysis of CDF attack, we highlight the method of evaluating potential threats hidden behind the normal VM migration and analyze the flaws of existing intrusion detection systems/prevention system for defensing the CDF attack.     

Inferring Passenger Denial Behavior of Taxi Drivers from Large-Scale Taxi Traces

How to understand individual human actions is a fundamental question to modern science, which drives and incurs many social, technological, racial, religious and economic phenomena. Human dynamics tries to reveal the temporal pattern and internal mechanism of human actions in letter or electronic communications, from the perspective of continuous interactions among friends or acquaintances. For interactions between stranger to stranger, taxi industry provide fruitful phenomina and evidence to investigate the action decisions. In fact, one striking disturbing events commonly reported in taxi industry is passenger refusing or denial, whose reasons vary, including skin color, blind passenger, being a foreigner or too close destination, religion reasons and anti specific nationality, so that complaints about taxi passenger refusing have to be concerned and processed carefully by local governments. But more universal factors for this phenomena are of great significance, which might be fulfilled by big data research to obtain novel insights in this question. In this paper, we demonstrate the big data analytics application in revealing novel insights from massive taxi trace data, which, for the first time, validates the passengers denial in taxi industry and estimates the denial ratio in Beijing city. We first quantify the income differentiation facts among taxi drivers. Then we find out that choosing the drop-off places also contributes to the high income for taxi drivers, compared to the previous explanation of mobility intelligence. Moreover, we propose the pick-up, drop-off and grid diversity concepts and related diversity analysis suggest that, high income taxi drivers will deny passengers in some situations, so as to choose the passengers’ destination they prefer. Finally we design an estimation method for denial ratio and infer that high income taxi drivers will deny passengers with 8.52% likelihood in Beijing. Our work exhibits the power of big data analysis in revealing some dark side investigation.     

Mass-dependence in the predation risk of unequal competitors; some models

Foragers can monitor their survival through the size of body reserves in a starvation/predation risk trade-off. Energy reserves reduce the risk of energetic shortfall, while survival will be maximised at intermediate reserve levels when there is a cost of carrying mass loads. The size of reserves that will maximise survival may not be identical for unequal competitors, when unequal access to resources will affect the costs and benefits of energy reserves. Here, I evaluate the effect of competitive ability (dominance) for the mass-dependence in predation risk and how it is affected by (1) attack rate (attack rate effect), (2) distance to the emergence of an unconcealed predator attack (attack distance effect) and (3) distance to cover (cover distance effect). This general model is illustrated by empirical data for parameters specific for birds. The effect of competitive ability for the mass-dependence in predation risk is ambiguous and depends on how rank is mediated into mass-dependent predation risk. Dominants pay a lower cost in predation risk for mass loads than sub-ordinates when competitive ability entails that they feed closer to cover (cover distance effect) and when the exposure to attacks and attack rate is lower than for sub-ordinates (attack rate effect) . In contrast, a shorter distance to the emergence of an unconcealed attack (attack distance effect) implies a lower increase in predation risk with mass for sub-ordinates. As a consequence of how the cost of mass load varies with conditions there is no unambiguous relationship for how predation risk can be traded off for starvation risk for individuals with different competitive ability.     

An analysis of the communication function of attack calls in little gulls

The communication function of two different vocalizations, termed ‘eeyit’ and ‘whèt’, made by little gulls, Larus minutus, to intruders near the nest was investigated by analysing the temporal relationship between these calls and overt attack (1) under natural circumstances and (2) in two experiments with intruder dummies. Eeyit was given prior to attack, whereas whèt coincided with the attack itself. Whether or not eeyit was followed by attack depended on the reaction of the intruder to this call. Eeyit seems to carry the message ‘I shall attack if provoked’, whereas whèt seems to function primarily by impressing the attacked bird, and by distracting its attention during the attack. Given the existence of marked within-individual constancy of eeyit, it is argued that honest information about a bird's attack motivation is transferred by this call in all situations.     

Effects of light level and growth history on attack distances of visually foraging juvenile salmon in experimental tanks

The effects of light level, developmental pathway, and previous growth history on the foraging attack distances of juvenile Atlantic salmon Salmo salar were examined in circular rearing tanks. Former manipulation of growth rates had no significant influence on distances moved to intercept food items despite the fact that it caused substantial differences in post-treatment growth. Attack distances of fish that were entering a state of overwinter dormancy (lower modal group; LMG) were shorter than those of actively feeding (and growing) fish (upper modal group; UMG). These differences were explained generally by differences in body size between the two groups, suggesting that actual effort per attack was unassociated with growth requirements. Significant differences between growing and non-growing fish in attack distances could contribute to the variation in growth rates through their effect on feeding rates, but were unlikely to have affected energetic costs. This may be due to the fact that attack distances were consistently short throughout the study period as is also evident from the pattern of change between night and daytime. Whereas in the first experiment (daylight v . twilight) fish moved further to reach food during the day, in the second (daylight v . overcast night) nocturnal attack distances matched (LMG fish) or exceeded (UMG fish) diurnal attack distances. Thus diurnal attack distances were probably minimized in the second experiment. These results are interpreted within a framework of overwintering strategies.     

Rhynchophorus ferrugineus attack affects a group of compounds rather than rearranging Phoenix canariensis metabolic pathways

The red palm weevil（RPW; Rhynchophorus ferrugineus） is spreading worldwide and severely harming many palm species. However, most studies on RPW focused on insect biology, and little information is available about the plant response to the attack. In the present experiment, we used metabolomics to study the alteration of the leaf metabolome of Phoenix canariensis at initial(1^st stage) or advanced(2^nd stage)attack by RPW compared with healthy（unattacked） plants.The leaf metabolome significantly varied among treatments. At the 1^st stage of attack, plants showed a reprogramming of carbohydrate and organic acid metabolism; in contrast, peptides and lipid metabolic pathways underwent more changes during the 2^nd than 1^st stage of attack. Enrichment metabolomics analysis indicated that RPW attack mostly affected a particular group of compounds rather than rearranging plant metabolic pathways. Some compounds selectively affected during the 1^st rather than 2^nd stage（e.g. phenylalanine; tryptophan; cellobiose;xylose; quinate; xylonite; idonate; and iso-threonate; cellobiotol and arbutine） are upstream events in the phenylpropanoid,terpenoid and alkaloid biosynthesis. These compounds could be designated as potential markers of initial RPW attack. However,further investigation is needed to determine efficient early screening methods of RPW attack based on the concentrations of these molecules.     

The physician's role in maintaining hope and spirituality

This paper examines several areas that health care providers may find difficult in the care of patients near the end of their lives. It looks at society's denial of death and at ways physicians and their patients use ongoing active treatments to maintain that denial. It suggests that as active treatment fails to be effective and hope fades, physicians must find ways to care for those they cannot cure. It explores the function of hope to help physicians, their patients, and their patients' families redirect their thinking. Finally, it describes how the physician may support a patient's spirituality by becoming more comfortable with his own.     

Predator attack motivation influences the inspection behaviour of European minnows

Predator inspection behaviour at different levels of attack motivation (attack status of the predator) was investigated in European minnows Phoxinus phoxinus from a population sympatric with pike Esox lucius , during controlled laboratory experiments. Shoals of minnows performed more predator inspections and formed larger inspection group sizes shortly after an attack by a pike. After inspection, minnows returned to the safety of the main shoal, regardless of predator motivation. Minnows which inspected last-before and first-after a strike by a pike modified their behaviour after inspection; they reduced feeding, increased shoaling, flicked their dorsal and pectoral fins and skittered. This behaviour signified alarm and appeared to reflect the severity of the threat posed by the predator at the time of inspection. Fish that had inspected when the pike displayed low attack motivation did not modify their behaviour after inspection to reflect alarm. Information concerning the attack motivation of the predator is probably transferred passively throughout the shoal by changed inspector behaviour and by inspection rate. These data demonstrate that: (1) minnows modified their behaviour after inspection to reflect a predator's attack motivation; and (2) minnows which inspected immediately before a strike appeared to anticipate the future attack and modified their behaviour accordingly.     

Death of a wild chimpanzee community member: possible outcome of intense sexual competition

Our observations strongly support the view that a lethal gang attack occurred against a young adult male within a wild chimpanzee (Pan troglodytes schweinfurthii) community. This is the first report of such an occurrence. At least three adult male chimpanzees are believed to have been involved in the attack. This case is unusual because the attack was fatal, involved directed group aggression within a community, and was not linked to the overthrow of the alpha male. During the period before the attack, the percentage of cycling females in the community was very low (15 males:17 females, a maximum of two regularly cycling). This fact, coupled with the presence of one female in full genital tumescence, may have incited and escalated the violence of the attack. The lethal attack is interpreted as an act of intra-community male sexual competition resulting in the complete exclusion of one male from estrous females.