107 resultados para panic attacks

em Deakin Research Online - Australia


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BACKGROUND: Panic attacks are common, and while they are not life-threatening events, they can lead to the development of panic disorder and agoraphobia. Appropriate help at the time that a panic attack occurs may decrease the fear associated with the attack and reduce the risk of developing an anxiety disorder. However, few people have the knowledge and skills required to assist. Simple first aid guidelines may help members of the public to offer help to people who experience panic attacks.

METHODS: The Delphi method was used to reach consensus in a panel of experts. Experts included 50 professionals and 6 people who had experience of panic attacks and were active in mental health advocacy. Statements about how to assist someone who is having a panic attack were sourced through a systematic search of both professional and lay literature. These statements were rated for importance as first aid guidelines by the expert and consumer panels and guidelines were written using the items most consistently endorsed.

RESULTS: Of 144 statements presented to the panels, 27 were accepted. These statements were used to develop the guidelines appended to this paper.

CONCLUSION: There are a number of actions which are considered to be useful for members of the public to do if they encounter someone who is having a panic attack. These guidelines will be useful in revision of curricula of mental health first aid programs. They can also be used by members of the public who want immediate information about how to assist someone who is experiencing panic attacks.

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The catastrophic misinterpretation model of panic disorder proposes that spontaneous panic attacks are the result of misinterpretation of harmless autonomic arousal as precursors to physical (e.g. heart attack) or psychological (e.g. insanity) emergency. Mixed research findings to date have provided equivocal support. A modified form of the Body Sensations Interpretation Questionnaire was used to investigate core assumptions of the model amongst 38 people with panic disorder (PD), 20 with non-clinical panic, 21 with social anxiety disorder, and 34 non-anxious controls. The PD group gave more harm-related interpretations of ambiguous internal stimuli than all other groups only when anxiety-related responses (e.g. “I'm going to panic”) were scored as harm, however there was no evidence that anxiety-related interpretations were masking perceived catastrophic physical or psychological outcomes. Despite this, people with PD rated harm and anxiety outcomes as more negative than non-anxious controls. Results failed to unequivocally support core assumptions of the model.

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Panic disorder can serve as a clinical model for testing whether mental stress can cause heart disease. Potential neural mechanisms of cardiac risk are the sympathetic activation during panic attacks, continuing release of adrenaline as a co-transmitter in the cardiac sympathetic nerves, and impairment of noradrenaline neuronal reuptake, augmenting sympathetic neural respnses.

The phenotype of impaired neuronal reuptake of noradrenaline: an epigenetic mechanism? We suspect that this phenotype, in sensitizing people to heart symptom development, is a cause of panic disorder, and by magnifying the sympathetic neural signal in the heart, underlies increased cardiac risk. No loss of function mutations of the coding region of the norepinephrine transporter (NET) are evident, but we do detect hypermethylation of CpG islands in the NET gene promoter region. Chromatin immunoprecipitation methodology demonstrates binding of the inhibitory transcription factor, MeCP2, to promoter region DNA in panic disorder patients.

Cardiovascular illnesses co-morbid with panic disorder. Panic disorder commonly coexists with essential hypertension and the postural tachycardia syndrome. In both of these cardiovascular disorders the impaired neuronal noradrenaline reuptake phenotype is also present and, as with panic disorder, is associated with NET gene promoter region DNA hypermethylation. An epigenetic ‘co-morbidity’ perhaps underlies the clinical concordance.

Brain neurotransmitters. Using internal jugular venous sampling, in the absence of a panic attack we find normal norepinephrine turnover, but based on measurements of the overflow of the serotonin metabolite, 5HIAA, a marked increase (six to sevenfold) in brain serotonin turnover in patients with panic disorder. This appears to represent the underlying neurotransmitter substrate for the disorder. Whether this brain serotonergic activation is a prime mover, or consequential on other primary causes of panic disorder, including cardiac sensitization by faulty neuronal noradrenaline reuptake leading to cardiac symptoms and the enhanced vigilance which accompanies them, is unclear at present.

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Objectives: Catechol-O-methyltransferase plays a central role in the metabolism of biogenic amines such as norepinephrine, dopamine and serotonin. Functional studies have demonstrated a dose relationship between Val158Met genotypes and catechol-O-methyltransferase activity. Compared with the Val158Val genotype, the Val158Met and Met158Met genotypes result in two- and four-fold reductions in catechol-O-methyltransferase activity, respectively. Two recent reports have observed the association between the Met158Met genotype and risk of anxiety in adult populations. We examined the association between the Val158Met genotypes and propensity to anxiety across adolescence.

Methods: Participants were drawn from an eight-wave study of the mental and behavioural health of over 2000 young Australians followed from 14 to 24 years of age (Victorian Adolescent Health Cohort Study, 1992 to present). DNA was received from 962 participants using a cheek swab collection method.

Results: The odds of reporting persistent episodic anxiety (phobic avoidance, panic attacks) were doubled among carriers of the Met158Met genotype (odds ratio 2.0, 95% confidence interval 1.1-3.4, P=0.014). A dose relationship between additional copies of the Met158 allele and persistent episodic anxiety was also observed (1.5, 1.1-1.94, P=0.007). Stratification by sex showed that the risk effect of the Met158 allele was among females only. No association was observed for measures of neuroticism, persistent generalized anxiety, or a composite measure of psychiatric distress.

Conclusion: These data replicate previous findings suggesting association between the Val158Met polymorphism and specific expressions of anxiety among females.

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Recently a number of highly publicised incidents of Distributed Denial of Service (DDoS) attacks have made people aware of the importance of providing available securely the grids’ data and services to users. This paper introduces the vulnerability of grids to DDoS attacks, and proposes a distributed defense system that has a mixture deployment of sub-systems to protect grids from DDoS attacks. According to the simulation experiments, this system is effective to defend grids against attacks. It can avoid overall network congestion and provide more resources to legitimate grid users.

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Recent algebraic attacks on LFSR-based stream ciphers and S-boxes have generated much interest as they appear to be extremely powerful. Theoretical work has been developed focusing around the Boo- lean function case. In this paper, we generalize this theory to arbitrary finite fields and extend the theory of annihilators and ideals introduced at Eurocrypt 2004 by Meier, Pasalic and Carlet. In particular, we prove that for any function f in the multivariate polynomial ring over GF(q), f has a low degree multiple precisely when two low degree functions appear in the same coset of the annihilator of f q – 1 – 1. In this case, many such low degree multiples exist.

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Distributed defense is a promising way to neutralize the distributed Denial-of-Service attacks by detecting and responding the attacking sources widespread around the Internet. Components of the distributed defense system will cooperate with each other to combat the attacks. Compared with the centralized defense systems, distributed defense systems can discover the attacks more timely from both source end and victim end, fight the attacks with more resources and take advantage of more flexible strategies. This paper investigates 7 distributed defense systems which make use of various strategies to mitigate the DDoS attacks. Different architectures are designed in these 7 systems to provide distributed DDoS defense solutions. We evaluate these systems in terms of deployment, detection, response, security, robustness and implementation. For each criteria, we give a recommendation on which technologies are best suitable for a successful distributed defense system based on the analysis result. Finally we propose our idea on the design of an effective distributed defense system.

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Nowadays Distributed Denial of Service (DDoS) attacks have made one of the most serious threats to the information infrastructure. In this paper we firstly present a new filtering approach, Mark-Aided Distributed Filtering (MADF), which is to find the network anomalies by using a back-propagation neural network, deploy the defense system at distributed routers, identify and filtering the attack packets before they can reach the victim; and secondly propose an analytical model for the interactions between DDoS attack party and defense party, which allows us to have a deep insight of the interactions between the attack and defense parties. According to the experimental results, we find that MADF can detect and filter DDoS attack packets with high sensitivity and accuracy, thus provide high legitimate traffic throughput and low attack traffic throughput. Through the comparison between experiments and numerical results, we also demonstrate the validity of the analytical model that can precisely estimate the effectiveness of a DDoS defense system before it encounters different attacks.

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Security protocols have been widely used to safeguard secure electronic transactions. We usually assume that principals are credible and shall not maliciously disclose their individual secrets to someone else. Nevertheless, it is impractical to completely ignore the possibility that some principals may collude in private to achieve a fraudulent or illegal purpose. Therefore, it is critical to address the possibility of collusion attacks in order to correctly analyse security protocols. This paper proposes a framework by which to detect collusion attacks in security protocols. The possibility of security threats from insiders is especially taken into account. The case study demonstrates that our methods are useful and promising in discovering and preventing collusion attacks.

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In the last a few years a number of highly publicized incidents of Distributed Denial of Service (DDoS) attacks against high-profile government and commercial websites have made people aware of the importance of providing data and services security to users. A DDoS attack is an availability attack, which is characterized by an explicit attempt from an attacker to prevent legitimate users of a service from using the desired resources. This paper introduces the vulnerability of web applications to DDoS attacks, and presents an active distributed defense system that has a deployment mixture of sub-systems to protect web applications from DDoS attacks. According to the simulation experiments, this system is effective in that it is able to defend web applications against attacks. It can avoid overall network congestion and provide more resources to legitimate web users.

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In this paper, we present a new approach, called Flexible Deterministic Packet Marking (FDPM), to perform a large-scale IP traceback to defend against Distributed Denial of Service (DDoS) attacks. In a DDoS attack the victim host or network is usually attacked by a large number of spoofed IP packets coming from multiple sources. IP traceback is the ability to trace the IP packets to their sources without relying on the source address field of the IP header. FDPM provides many flexible features to trace the IP packets and can obtain better tracing capability than current IP traceback mechanisms, such as Probabilistic Packet Marking (PPM), and Deterministic Packet Marking (DPM). The flexibilities of FDPM are in two ways, one is that it can adjust the length of marking field according to the network protocols deployed; the other is that it can adjust the marking rate according to the load of participating routers. The implementation and evaluation demonstrates that the FDPM needs moderately only a small number of packets to complete the traceback process; and can successfully perform a large-scale IP traceback, for example, trace up to 110,000 sources in a single incident response. It has a built-in overload prevention mechanism, therefore this scheme can perform a good traceback process even it is heavily loaded.

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The possible shortage of applicants for principal positions is news in both Australia and abroad. We subject a corpus of predominantly United states (US) news articles to deconstructive narrative analysis and find that the dominant media representation of principals' work is one of long hours Iow salary high stress and sudden death from high stakes accountabilities. However, reported US policy interventions focus predominantly on professional development for aspirants. We note that this will be insufficient to reverse the lack of applications and suggest that the dominant media picture of completely unattractive principals work, meant to leverage a policy solution, will perhaps paradoxically perpetuate the problem. The dominant media picture is also curiously at odds with research that reports high job satisfaction among principals. We suggest that there is a binary of victim and saviour principal in both media and policy which prevents some strategic re-thinking about how the principalship might be different.

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Wireless sensor networks represent a new generation of real-time  embedded systems with significantly different communication constraints from the traditional networked systems. With their development, a new attack called a path-based DoS (PDoS) attack has appeared. In a PDoS attack, an adversary, either inside or outside the network, overwhelms sensor nodes by flooding a multi-hop endto- end communication path with either replayed packets or injected spurious packets. In this article, we propose a solution using mobile agents which can detect PDoS attacks easily.