2,790 research outputs found
Identifying packet droppers in sensor networks via report analysis
In an unattended sensor network, sensor nodes can be compromised. Based on compromised nodes, the adversary can launch various attacks and packet dropping is one of the easiest attacks. Many schemes have been proposed to mitigate the packet dropping attack, but few can effectively and efficiently identify the droppers. In this thesis, we propose a simple yet effective scheme to identify packet droppers. This scheme only requires sending and forwarding nodes to report their observations to the base station, and the base station can analyze the reports, identify inconsistencies in the reports, and then locate the droppers. All nodes are organized into a tree rooted at the base station and each node is required to report the number of packets it has received as well as the number and the composition of packets forwarded by its parent node on the tree, which it has overheard. Using rules we propose, the base station can analyze the received reports to check if there is inconsistency among the reports; if some inconsistencies are found, the base station can further infer the identities of packet droppers. The scheme can also tolerate erroneous reports, natural packet dropping and so on. A mark-based scheme is also proposed to identify packet dropper or modifier. Extensive simulations have been conducted to demonstrate the effectiveness of the scheme
Classification of equivariant real vector bundles over a circle
This is a continuation of the authors' previous work [math.AT/9910001] on
classification of equivariant complex vector bundles over a circle. In this
paper we classify equivariant real vector bundles over a circle with a compact
Lie group action, by characterizing the fiber representations of them, and by
using the result of the complex case. We also treat the triviality of them. The
basic phenomenon is similar to the complex case but more complicated here.Comment: 16 pages, AMS-LaTeX v1.
Classification of Equivariant Complex Vector Bundles over a Circle
In this paper we characterize the fiber representations of equivariant
complex vector bundles over a circle and classify these bundles. We also treat
the triviality of equivariant complex vector bundles over a circle by
investigating the extensions of representations. As a corollary of our results,
we calculate the reduced equivariant K-group of a circle for any compact Lie
group.Comment: 15 pages, AMS-LaTeX v1.
Legislative History of the Special Adoption Act (Legislative History) (2012) (Korea)
In order to focus adoption procedures on the welfare of the child, national supervision must be strengthened, and a policy must be established around the basic paradigm that the best protection of a child is for the child to be raised by his/her birth family and in his/her birth country
Special Adoption Act (2012) (Korea)
The purpose of this Act is to set forth the necessary requirements and procedures of adopting a child in need of protection, and other matters necessary to support such adoptions, which are all aimed at promoting the rights and welfare of the adopted child
Combination of Medicinal Herbs KIOM-79 Reduces Advanced Glycation End Product Accumulation and the Expression of Inflammatory Factors in the Aorta of Zucker Diabetic Fatty Rats
Previous studies have reported that KIOM-79 shows a strong inhibitory effect on AGE formation and inhibited a proinflammatory state in a murine macrophage cell line. In the present study, we investigated the effect of KIOM-79 on AGE accumulation and vascular inflammation in the aorta of Zucker diabetic fatty (ZDF) rats, a commonly used model of type 2 diabetes. Seven-week-old male ZDF rats were treated with KIOM-79 (50 mg/kg) once a day orally for 13 weeks. We examined the dissected aortas for AGE accumulation, expression of the receptor for AGEs (RAGE), and the expression of proinflammatory factors, including monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF), and vascular adhesion molecule-1 (VCAM-1). Nuclear factor-kappaB (NF-κB) and inducible nitric oxide synthase (iNOS) were also measured by Southwestern histochemistry, electrophoretic mobility shift assay (EMSA), and immunohistochemistry, respectively. KIOM-79 markedly reduced the accumulation of AGEs and the expression of RAGE in the aorta. We also found that KIOM-79 attenuated the expression of inflammatory factors including NF-κB, MCP-1, VEGF, VCAM-1, and iNOS in the aortas of ZDF rats. These data suggest that KIOM-79 may prevent or retard the development of inflammation in diabetic vascular disease
Renal Podocyte Injury in a Rat Model of Type 2 Diabetes Is Prevented by Metformin
Hyperglycemia promotes oxidative stress and hence generation of reactive oxygen species (ROS), which is known to play a crucial role in the pathogenesis of diabetic nephropathy. Metformin, an oral hypoglycemic drug, possesses antioxidant effects. The aim of this paper is to investigate the protective effects of metformin on the injury of renal podocytes in spontaneously diabetic Torii (SDT) rats, a new model for nonobese type 2 diabetes. Metformin (350 mg/kg/day) was given to SDT rats for 17 weeks. Blood glucose, glycated haemoglobin (HbA1c), and albuminuria were examined. Kidney histopathology, renal 8-hydroxydeoxyguanosine (8-OHdG) levels and apoptosis were examined. In 43-week-old SDT rats, severe hyperglycemia was developed, and albuminuria was markedly increased. Diabetes induced significant alterations in renal glomerular structure. In addition, urinary and renal 8-OHdG levels were highly increased, and podocyte loss was shown through application of the TUNEL and synaptopodin staining. However, treatment of SDT rats with metformin restored all these renal changes. Our data suggested that diabetes-induced podocyte loss in diabetic nephropathy could be suppressed by the antidiabetes drug, metformin, through the repression of oxidative injury
KIOM-79, an Inhibitor of AGEs–Protein Cross-linking, Prevents Progression of Nephropathy in Zucker Diabetic Fatty Rats
Advanced glycation end products (AGEs) have been implicated in the development of diabetic complications, including diabetic nephropathy. KIOM-79, an 80% ethanolic extract obtained from parched Puerariae Radix, gingered Magnolia Cortex, Glycyrrhiza Radix and Euphorbia Radix, was investigated for its effects on the development of renal disease in Zucker diabetic fatty rats, an animal model of type 2 diabetes. In vitro inhibitory effect of KIOM-79 on AGEs cross-linking was examined by enzyme-linked immunosorbent assay (ELISA). KIOM-79 (50 mg/kg/day) was given to Zucker diabetic fatty rats for 13 weeks. Body and kidney weight, blood glucose, glycated hemoglobin, urinary albumin and creatinine excretions were monitored. Kidney histopathology, collagen accumulation, fibrinogen and transforming growth factor-beta 1 (TGF-β1) expression were also examined. KIOM-79 reduced blood glucose, kidney weight, histologic renal damage and albuminuria in Zucker diabetic fatty rats. KIOM-79 prevented glomerulosclerosis, tubular degeneration, collagen deposition and podocyte apoptosis. In the renal cortex, TGF-β1, fibronectin mRNA and protein were significantly reduced by KIOM-79 treatment. KIOM-79 reduces AGEs accumulation in vivo, AGE–protein cross-linking and protein oxidation. KIOM-79 could be beneficial in preventing the progression of diabetic glomerularsclerosis in type 2 diabetic rats by attenuating AGEs deposition in the glomeruli
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Periodontitis-induced systemic inflammation exacerbates atherosclerosis partly via endothelial-mesenchymal transition in mice.
Growing evidence suggests close associations between periodontitis and atherosclerosis. To further understand the pathological relationships of these associations, we developed periodontitis with ligature placement around maxillary molars or ligature placement in conjunction with Porphyromonas gingivalis lipopolysaccharide injection at the ligature sites (ligature/P.g. LPS) in Apolipoprotein E knock out mice and studied the atherogenesis process in these animals. The mice were fed with high fat diet for 11 weeks and sacrificed for analyzing periodontitis, systemic inflammation, and atherosclerosis. Controls did not develop periodontitis or systemic inflammation and had minimal lipid deposition in the aortas, but mice receiving ligature or ligature/P.g. LPS showed severe periodontitis, systemic inflammation, and aortic plaque formation. The aortic plaque contained abundant macrophages and cells expressing both endothelial and mesenchymal cell markers. The severity of periodontitis was slightly higher in mice receiving ligature/P.g. LPS than ligature alone, and the magnitude of systemic inflammation and aortic plaque formation were also notably greater in the mice with ligature/P.g. LPS. These observations indicate that the development of atherosclerosis is due to systemic inflammation caused by severe periodontitis. In vitro, P.g. LPS enhanced the secretion of pro-inflammatory cytokines from macrophages and increased the adhesion of monocytes to endothelial cells by upregulating the expression of adhesion molecules from endothelial cells. Moreover, secretory proteins, such as TNF-α, from macrophages induced endothelial-mesenchymal transitions of the endothelial cells. Taken together, systemic inflammation induced by severe periodontitis might exacerbate atherosclerosis via, in part, causing aberrant functions of vascular endothelial cells and the activation of macrophages in mice
Seismic response of beam-column joints rehabilitated with FRP sheets and buckling restrained braces
An experimental test was performed to evaluate the seismic resistance of reinforced concrete beam-column joints rehabilitated with FRP sheets and Buckling Restrained Braces (BRBs). Six beam-column joints were rehabilitated and tested. The test results were compared in terms of hysteresis loops, stiffness degradation, energy dissipation and ductility. The comparison result showed that wrapping FRP sheets can contribute to increase the effect of confinement and to delay crack development in the joints. Also retrofitting buckling restrained braces (BRBs) can improve the stiffness and energy dissipation capacity. Both FRP sheets and BRBs can effectively improve the strength, stiffness and ductility
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