133 research outputs found

    Precise ICMP Traceback Based On Normal Flow Filtration in Denial of Services Attack

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    In past two decades, Internet has developed rapidly and has integrated in many aspects of human life. Any disruption of connectivity and the overuse of services cause for service unavailability to its intended users. The Denial of Service (DoS) attacks are becoming more serious in security of Internet. DoS is a harmful attempt in targeting to limit or deny availability of service to legitimate users. This kind of attack can be done by consuming important resources. The best action is to block the attack traffic at its source. There is no easy way to this approach because attacker can spoof the source IP address easily. Traceback models try to locate source of attack regardless of whether the source address field in each packet contains false information or not. Intention-driven model, a sampling traceback technique, provides information about the attack flow and able to reconstruct the attack path to the source of attack by the aid of Intrusion Detection system (IDS). This technique does not have any flow differentiate mechanism. In other words, it is unable to differentiate legitimate user and attacker, when both of them sending packet via same route to the victim. As a result, providing incorrect information and locate false point about the source of attack. To overcome this weakness, this research aims to increase the generation of more useful ICMP traceback packets, which includes attack path information. More useful information about the attack flow provided by the routers along the attack path to the IDS, can provide higher accuracy to locate the attacker. To achieve such a goal, this research improves the Intention-driven ICMP traceback model by filtering normal flow in the specific short time and two new algorithms in UDP-based and TCP-based attack are applied. As a consequence of filtering of normal flow, the percentage of packets belonging to the attack flow will be expanded and the chance of generating ICMP traceback messages which contain attack flow information will be increased. The results show the proposed model used in this research increases the percentage of useful ICMP traceback messages in UDP-based attack about 10% and 14% in the TCP-based attack when compared to the previous work. The proposed model also decreases percentage of ineffective generated iTrace packets in both UDP-based and TCP-based attack about 10%

    The effect of orally consumed Lactuca sativa syrup on human milk volume and weight gain in the preterm infant:a randomized controlled clinical trial

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    Abstract Human milk feeding can support premature infants to thrive. Yet those with premature infants can be challenged in human milk production. Considering this, and the use of potentially harmful human milk enhancers, the present study was conducted with the aim of determining the effect of orally consumed Lactuca sativa (L. sativa) syrup (lettuce extract) on human milk volume and subsequent weight gain in the preterm infant. Extracts from lettuce and other plants such as silymarin are already evidenced to be safe for use during lactation and have other therapeutic effects in humans. Yet this is the first study of its kind. This parallel randomized clinical trial included lactating participants with their preterm infants who were born at < 32 weeks' gestation and admitted to an intensive care unit. Convenience sampling was used to recruit participants. Eligible participants were allocated to groups randomly: intervention (n = 47), placebo (n = 46), and control (n = 47). The intervention group received one tablespoon of Lactuca sativa (L. sativa) syrup, and the placebo group received one tablespoon of placebo syrup 3 times a day for 1 week. Those in the control group did not receive any herbal or chemical milk-enhancing compounds. Routine care was provided to all three groups. Participants recorded their milk volume for 7 days in a daily information recorder form. Infant weight was measured prior to the intervention, and on the third, fifth and seventh days of the intervention period. There was a statistically significant difference observed in the adjusted mean volume of milk on the fourth and fifth days between the intervention, placebo, and control groups (P < 0.05). The adjusted mean milk volume of those in the intervention group on the first day was significantly higher than those in the control group and those in the placebo group. On the second day, the adjusted mean milk volume of those in the intervention group was higher than in those from the control group; and on the fourth day it was higher than in those from both the control and placebo groups; on the fifth day it was higher than in those in the placebo group; on the sixth day it was higher than in those in the control group and on the seventh day it was higher than in those in the control group (P < 0.05). There was no statistically significant difference in terms of the mean changes (with or without adjustment) in the weight of preterm infants between any of the groups. Lactuca sativa (L. sativa) syrup increases the volume of human milk production and no specific side effects have been reported in its use. Therefore, Lactuca sativa syrup can be recommended for use as one of the compounds that increase human milk volume

    Establishing effective communications in disaster affected areas and artificial intelligence based detection using social media platform

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    Floods, earthquakes, storm surges and other natural disasters severely affect the communication infrastructure and thus compromise the effectiveness of communications dependent rescue and warning services. In this paper, a user centric approach is proposed to establish communications in disaster affected and communication outage areas. The proposed scheme forms ad hoc clusters to facilitate emergency communications and connect end-users/ User Equipment (UE) to the core network. A novel cluster formation with single and multi-hop communication framework is proposed. The overall throughput in the formed clusters is maximized using convex optimization. In addition, an intelligent system is designed to label different clusters and their localities into affected and non-affected areas. As a proof of concept, the labeling is achieved on flooding dataset where region specific social media information is used in proposed machine learning techniques to classify the disaster-prone areas as flooded or unflooded. The suitable results of the proposed machine learning schemes suggest its use along with proposed clustering techniques to revive communications in disaster affected areas and to classify the impact of disaster for different locations in disaster-prone areas

    Multiple domains in the Crumbs Homolog 2a (Crb2a) protein are required for regulating rod photoreceptor size

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    Background Vertebrate retinal photoreceptors are morphologically complex cells that have two apical regions, the inner segment and the outer segment. The outer segment is a modified cilium and is continuously regenerated throughout life. The molecular and cellular mechanisms that underlie vertebrate photoreceptor morphogenesis and the maintenance of the outer segment are largely unknown. The Crumbs (Crb) complex is a key regulator of apical membrane identity and size in epithelia and in Drosophila photoreceptors. Mutations in the human gene CRUMBS HOMOLOG 1 (CRB1) are associated with early and severe vision loss. Drosophila Crumbs and vertebrate Crb1 and Crumbs homolog 2 (Crb2) proteins are structurally similar, all are single pass transmembrane proteins with a large extracellular domain containing multiple laminin- and EGF-like repeats and a small intracellular domain containing a FERM-binding domain and a PDZ-binding domain. In order to begin to understand the role of the Crb family of proteins in vertebrate photoreceptors we generated stable transgenic zebrafish in which rod photoreceptors overexpress full-length Crb2a protein and several other Crb2a constructs engineered to lack specific domains. Results We examined the localization of Crb2a constructs and their effects on rod morphology. We found that only the full-length Crb2a protein approximated the normal localization of Crb2a protein apical to adherens junctions in the photoreceptor inner segment. Several Crb2a construct proteins localized abnormally to the outer segment and one construct localized abnormally to the cell body. Overexpression of full-length Crb2a greatly increased inner segment size while expression of several other constructs increased outer segment size. Conclusions Our observations suggest that particular domains in Crb2a regulate its localization and thus may regulate its regionalized function. Our results also suggest that the PDZ-binding domain in Crb2a might bring a protein(s) into the Crb complex that alters the function of the FERM-binding domain

    Genetic Interaction of Centrosomin and Bazooka in Apical Domain Regulation in Drosophila Photoreceptor

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    Cell polarity genes including Crumbs (Crb) and Par complexes are essential for controlling photoreceptor morphogenesis. Among the Crb and Par complexes, Bazooka (Baz, Par-3 homolog) acts as a nodal component for other cell polarity proteins. Therefore, finding other genes interacting with Baz will help us to understand the cell polarity genes' role in photoreceptor morphogenesis. mutation on developing eyes to determine its role in photoreceptor morphogenesis. We found that Cnn is dispensable for retinal differentiation in eye imaginal discs during the larval stage. However, photoreceptors deficient in Cnn display dramatic morphogenesis defects including the mislocalization of Crumbs (Crb) and Bazooka (Baz) during mid-stage pupal eye development, suggesting that Cnn is specifically required for photoreceptor morphogenesis during pupal eye development. This role of Cnn in apical domain modulation was further supported by Cnn's gain-of-function phenotype. Cnn overexpression in photoreceptors caused the expansion of the apical Crb membrane domain, Baz and adherens junctions (AJs). photoreceptor

    Activation of JNK Signaling Mediates Amyloid-ß-Dependent Cell Death

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    Alzheimer's disease (AD) is an age related progressive neurodegenerative disorder. One of the reasons for Alzheimer's neuropathology is the generation of large aggregates of Aß42 that are toxic in nature and induce oxidative stress, aberrant signaling and many other cellular alterations that trigger neuronal cell death. However, the exact mechanisms leading to cell death are not clearly understood.We employed a Drosophila eye model of AD to study how Aß42 causes cell death. Misexpression of higher levels of Aß42 in the differentiating photoreceptors of fly retina rapidly induced aberrant cellular phenotypes and cell death. We found that blocking caspase-dependent cell death initially blocked cell death but did not lead to a significant rescue in the adult eye. However, blocking the levels of c-Jun NH(2)-terminal kinase (JNK) signaling pathway significantly rescued the neurodegeneration phenotype of Aß42 misexpression both in eye imaginal disc as well as the adult eye. Misexpression of Aß42 induced transcriptional upregulation of puckered (puc), a downstream target and functional read out of JNK signaling. Moreover, a three-fold increase in phospho-Jun (activated Jun) protein levels was seen in Aß42 retina as compared to the wild-type retina. When we blocked both caspases and JNK signaling simultaneously in the fly retina, the rescue of the neurodegenerative phenotype is comparable to that caused by blocking JNK signaling pathway alone.Our data suggests that (i) accumulation of Aß42 plaques induces JNK signaling in neurons and (ii) induction of JNK contributes to Aß42 mediated cell death. Therefore, inappropriate JNK activation may indeed be relevant to the AD neuropathology, thus making JNK a key target for AD therapies

    Role of Kinesin Heavy Chain in Crumbs Localization along the Rhabdomere Elongation in Drosophila Photoreceptor

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    BACKGROUND:Crumbs (Crb), a cell polarity gene, has been shown to provide a positional cue for the extension of the apical membrane domain, adherens junction (AJ), and rhabdomere along the growing proximal-distal axis during Drosophila photoreceptor morphogenesis. In developing Drosophila photoreceptors, a stabilized microtubule structure was discovered and its presence was linked to polarity protein localization. It was therefore hypothesized that the microtubules may provide trafficking routes for the polarity proteins during photoreceptor morphogenesis. This study has examined whether Kinesin heavy chain (Khc), a subunit of the microtubule-based motor Kinesin-1, is essential in polarity protein localization in developing photoreceptors. METHODOLOGY/PRINCIPAL FINDINGS:Because a genetic interaction was found between crb and khc, Crb localization was examined in the developing photoreceptors of khc mutants. khc was dispensable during early eye differentiation and development. However, khc mutant photoreceptors showed a range of abnormalities in the apical membrane domain depending on the position along the proximal-distal axis in pupal photoreceptors. The khc mutant showed a progressive mislocalization in the apical domain along the distal-proximal axis during rhabdomere elongation. The khc mutation also led to a similar progressive defect in the stabilized microtubule structures, strongly suggesting that Khc is essential for microtubule structure and Crb localization during distal to proximal rhabdomere elongation in pupal morphogenesis. This role of Khc in apical domain control was further supported by khc's gain-of-function phenotype. Khc overexpression in photoreceptors caused disruption of the apical membrane domain and the stabilized microtubules in the developing photoreceptors. CONCLUSIONS/SIGNIFICANCE:In summary, we examined the role of khc in the regulation of the apical Crb domain in developing photoreceptors. Since the rhabdomeres in developing pupal eyes grow along the distal-proximal axis, these phenotypes suggest that Khc is essential for the microtubule structures and apical membrane domains during the distal-proximal elongation of photoreceptors, but is dispensable for early eye development
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