The development of a Defense System against Coxsackievirus B5 Infection in Suckling Mice

There are many viruses that are able to infect the alimentary tract of man. Little is known, however, about the mechanism of infection itself or the pathophysiology of the gut during infection. 'The research reported here is concerned with the differences in susceptibility among suckling mice of various ages inoculated by the intraperitoneal and intragastric routes. Since the normal mode of entry of many viruses to the gut is via the oral route, Coxsackievirus B5, a human enterovirus which does attack this way, was utilized. It is a non-tumor producing RNA virus that has been shown to act similarly in the mouse and human. The virus was pooled in HeLa cell cultures and titered by a plaquing assay in the same cell cultures. CD-l mice, 10, 14, 18, and 22 days old , were infected either orally or intraperitoneally with 5.0 x 10^10 (10 day old animals) and 1.0 x10^9 plaque forming units per animal. Dissections were done at 1 and 3 days post infection with samples of the blood, heart, liver, and gut being taken from each animal. Each sample was titered individually and the data presented as an average of six samples. As a result of previous work, it is known that the gut of a newborn mouse isn't able to decrease the concentration of the infecting dose and therefore provides no defense against an enteric infection with Coxsackievirus B5. In contrat, mature mice are able to reduce the amount of viral dissemination across the gut as well as inhibit replication after absorption has occurred. The results of this study indicate that there is a double barrier system developing in suckling mice that is involved with and directly related to the gastrointestinal tract The first part of this defense is the inhibition of penetration of virus across the gut when the primary site of' infection is the intestinal mucosa. This mechanism develops sometime around 20 to 22 days after birth. At about 16-18 days of age, suckling mice that were challenged intragastrically are able to stop active replication and initiate clearance of virus from the systemic circulation. There are many factors that might contribute to the marked decrease in susceptibility with age of suckling mice. Some of these or possibly a combination of these factors might explain the defense mechanisms described above, but to date, the chemistry or mechanical functioning of the gastrointestinal barrier to enteric viral infection is unknown.

Using immune genetic algorithm to optimize the reactive power

A novel algorithm, immune genetic algorithm (IGA) is proposed for reactive power optimization of power system. While retaining excellent characteristics of genetic algorithm (GA), through imitating the biological immune system, the algorithm evaluates and selects the optimal solutions by the affinities between antigens and antibodies. With the regulation of the activating and suppressing of antibodies, IGA can achieve the dynamic balance between individual diversity and population convergence, and avoid getting into the local optimal solution. The proposed IGA is applied to the IEEE 30-bus system, and the results show that it is superior to the GA with good population convergence and fast computing speed.

UV-induced DNA damage promotes resistance to the biotrophic pathogen Hyaloperonospora parasitica in Arabidopsis

Plant innate immunity to pathogenic microorganisms is activated in response to recognition of extracellular or intracellular pathogen molecules by transmembrane receptors or resistance proteins, respectively. The defense signaling pathways share components with those involved in plant responses to UV radiation, which can induce expression of plant genes important for pathogen resistance. Such intriguing links suggest that UV treatment might activate resistance to pathogens in normally susceptible host plants. Here, we demonstrate that pre-inoculative UV (254 nm) irradiation of Arabidopsis (Arabidopsis thaliana) susceptible to infection by the biotrophic oomycete Hyaloperonospora parasitica, the causative agent of downy mildew, induces dose- and time-dependent resistance to the pathogen detectable up to 7 d after UV exposure. Limiting repair of UV photoproducts by postirradiation incubation in the dark, or mutational inactivation of cyclobutane pyrimidine dimer photolyase, (6-4) photoproduct photolyase, or nucleotide excision repair increased the magnitude of UV-induced pathogen resistance. In the absence of treatment with 254-nm UV, plant nucleotide excision repair mutants also defective for cyclobutane pyrimidine dimer or (6-4) photoproduct photolyase displayed resistance to H. parasitica, partially attributable to short wavelength UV-B (280–320 nm) radiation emitted by incubator lights. These results indicate UV irradiation can initiate the development of resistance to H. parasitica in plants normally susceptible to the pathogen and point to a key role for UV-induced DNA damage. They also suggest UV treatment can circumvent the requirement for recognition of H. parasitica molecules by Arabidopsis proteins to activate an immune response.

Protein kinase C isozymes as potential therapeutic targets in immune disorders

Background: Members of the protein kinase C (PKC) family are key signalling mediators in immune responses, and pharmacological inhibition of PKCs may be useful for treating immune-mediated diseases. Objective: To review and discuss the insights gained so far into various PKC isozymes and the therapeutic potential and challenges of developing PKC inhibitors for immune disorder therapy. Methods: A literature review of the role of PKCs in immune cell signalling and recent studies describing immune functions associated with PKC isozyme deficiency in relevant mouse disease models, followed by specific case studies of current and potential therapeutic strategies targeting PKCs. Results/conclusion: There is vast amount of data supporting PKC isozymes as attractive drug targets for certain immune disorders. Although the development of specific PKC isozyme inhibitors has been challenging, some progress has been made. It remains to be seen if broad-scale or isozyme-selective inhibition of PKC will have clinical efficacy.

Brief report : The defense mechanisms of homophobic adolescent males : a descriptive discriminant analysis

The study examined the role of defense mechanisms in homophobic attitudes of older male adolescents aged 17e18 years. A cross-sectional survey collected data from final year high school students (N ¼ 86) attending an all male school in a regional centre in Victoria, Australia. The school was identified by teachers as having a problematic culture of homophobic intolerance. Participants were divided into homophobic and non-homophobic groups based on their scores on the Homophobia Scale Questionnaire. Discriminant analysis was conducted to identify the predictors that would best categorise students into those two groups on the basis of defense styles derived from the Defense Style Questionnaire-40 (DSQ-40). The strongest predictors of homophobia amongst defense styles were idealisation, denial, somatisation and devaluation accounting for 18.31%, 17.64%, 13.10% and 11.35% of the variance, respectively. Results generally supported the larger contribution of more immature defenses to higher levels of homophobia.

Multi-core security defense system (MSDS)

Today's security program developers are not only facing an uphill battle of developing and implementing. But now have to take into consideration, the emergence of next generation of multi-core system, and its effect on security application design. In our previous work, we developed a framework called bodyguard. The objective of this framework was to help security software developers, shift from their use of serialized paradigm, to a multi-core paradigm. Working within this paradigm, we developed a security bodyguard system called Farmer. This abstract framework placed particular applications into categories, like security or multi-media, which were ran on separate core processors within the multi-core system. With further analysis of the bodyguard paradigm, we found that this paradigm was suitable to be used in other computer science areas, such as spam filtering and multi-media. In this paper, we update our research work within the bodyguard paradigm, and showed a marked improvement of 110% speedup performance with an average cost of 1.5 ms.

Multi-core Defense System (MSDS) for protecting computer infrastructure against DDoS attacks

Distributed Denial of Service attacks is one of the most challenging areas to deal with in Security. Not only do security managers have to deal with flood and vulnerability attacks. They also have to consider whether they are from legitimate or malicious attackers. In our previous work we developed a framework called bodyguard, which is to help security software developers from the current serialized paradigm, to a multi-core paradigm. In this paper, we update our research work by moving our bodyguard paradigm, into our new Ubiquitous Multi-Core Framework. From this shift, we show a marked improvement from our previous result of 20% to 110% speedup performance with an average cost of 1.5 ms. We also conducted a second series of experiments, which we trained up Neural Network, and tested it against actual DDoS attack traffic. From these experiments, we were able to achieve an average of 93.36%, of this attack traffic.

Modelling the relationship between defense spending and economic growth for the Fiji Islands

The goal of this paper is to examine the nexus between GDP and military expenditure. We model this relationship within a multivariate framework by including exports in the model. We use the recently developed bounds testing approach to cointegration and find that there is a long run relationship among the variables when GDP is the endogenous variable. Normalizing on GDP and using four different estimators, we find that in the long run both military expenditure and exports have a positive impact on GDP. Finally, using the Granger causality test, we find that there is evidence for military expenditure Granger causing exports and exports Granger causing GDP, implying that military expenditure indirectly Granger causes GDP in the short run. In the long run, we find that both military expenditure and exports Granger cause GDP for Fiji. Our findings are consistent with the Keynesian school of thought, leading us to derive some policy implications.

Effect of zinc supplementation on the immune status of healthy older individuals aged 55–70 years : the ZENITH Study

Aging is associated with alterations in the immune system, effects which may be exacerbated by inadequate zinc (Zn) status. We examined the relationship between Zn status and markers of immunity and the effect of supplementation with 15 mg or 30 mg Zn/d for 6 months on immune status in healthy individuals. Zn status was assessed by dietary intake and biochemical indices. Immune status was assessed by multiple flow cytometric methods. At baseline, Zn concentration was positively associated with lymphocyte subpopulation counts and T-lymphocyte activation. Zn supplementation of 30 mg/d significantly lowered B-lymphocyte count, albeit at month 3 only. Lower doses of Zn (15 mg Zn/d) significantly increased the ratio of CD4 to CD8 T lymphocytes at month 6. Overall, these findings suggest that total Zn intake (diet plus supplementation) of up to 40 mg Zn/d do not have significant long-term effects on immune status in apparently healthy persons aged 55–70 years.

Optimal immune responses : immunocompetence revisited

The function of the immune system of an animal is to provide defence against infection, in order to maximize fitness. Understanding this and, particularly, how limiting resources are traded off between costly immune responses and other physiological demands, is central to properly understanding life-history traits and their evolution. Here, we propose that functional (rather than immunological) measures of immune responses should be used when investigating this. We further suggest that optimal immune responses are context specific, rather than generic; that is, a maximum immune response is not necessarily optimal. The nature of an optimal immune response will depend on the specific circumstances and infection status of the animal. Identifying and understanding such optimality requires that the effects of different immune strategies on fitness be considered.