Heuristic for the design of fault tolerant logical topology.

Wavelength division multiplexing (WDM) in optical fiber networks is widely viewed as the savior for its potential to satisfy the huge bandwidth requirement of network users. Optical cross connect (OCX) in WDM network facilitates the switching of signal on any wavelength from any input port to any output port. As a result, it is possible to establish ligthpaths between any pair of nodes. The set of lightpaths established over fiber links defines logical topology. In our thesis, we proposed a heuristic approach for the design of fault tolerant logical topology. Our design approach generalizes the design protection concept and enforces wavelength continuity constraint in a multi-hop optical network. In our work, we first designed logical topology for fault free state of the network. We, then, added additional lightpaths for each single link failure scenario. Numerical results clearly show that our approach outperforms Shared path protection and Dedicated path protection. Our simulation result shows that our approach is feasible for large networks. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .S24. Source: Masters Abstracts International, Volume: 44-03, page: 1413. Thesis (M.Sc.)--University of Windsor (Canada), 2005

Arsenic awareness creation

An estimated 20-30 million people consume water with arsenic concentrations above 0.05 mg/L (Ground Water Studies for Arsenic Contamination in Bangladesh, 2000) and are under risk of arsenic poisoning and adverse impact on health. With the huge number of people at risk and the widespread nature of the arsenic contamination (excess amounts of arsenic in tube-wells have been detected in 53 out of 64 Districts in Bangladesh), effective community participation is reckoned as a pre-requisite for a sustained arsenic mitigation program. To test promising arsenic mitigation treatment technologies (Rahman et al., 2000), the DPHE-Danida Arsenic Mitigation Pilot Project selected 4,000 families in the fringe areas of Chaumuhani and Lakshmipur Pourashavas in the coastal region of Bangladesh. In these Pilot Areas the Project employed and trained local women to carry out a Baseline survey, to conduct an intensive awareness creation campaign, to create demand for arsenic mitigation and to install and train the users in the operation of the DPHEDanida developed Bucket Treatment Unit (BTU) technology

Malabaricone-A Induces A Redox Imbalance That Mediates Apoptosis in U937 Cell Line

BACKGROUND: The 'two-faced' character of reactive oxygen species (ROS) plays an important role in cancer biology by acting both as secondary messengers in intracellular signaling cascades and sustaining the oncogenic phenotype of cancer cells, while on the other hand, it triggers an oxidative assault that causes a redox imbalance translating into an apoptotic cell death. PRINCIPAL FINDINGS: Using a tetrazolium [{3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl}-2H-tetrazolium] based cell viability assay, we evaluated the cytotoxicity of a plant derived diarylnonanoid, malabaricone-A on leukemic cell lines U937 and MOLT-3. This cytotoxicity hinged on its ability to cause a redox imbalance via its ability to increase ROS, measured by flow cytometry using 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate and by decreasing glutathione peroxidase activity. This redox imbalance mediated apoptosis was evident by an increase in cytosolic [Ca(2+)], externalization of phosphatidyl serine as also depolarization of the mitochondrial membrane potential as measured by flow cytometry. There was concomitant peroxidation of cardiolipin, release of free cytochrome c to cytosol along with activation of caspases 9, 8 and 3. This led to cleavage of the DNA repair enzyme, poly (ADP-ribose) polymerase that caused DNA damage as proved by labeling with 4',6-diamidino-2-phenylindole (DAPI); furthermore, terminal deoxy ribonucleotide transferase catalysed incorporation of deoxy uridine triphosphate confirmed DNA nicking and was accompanied by arrest of cell cycle progression. CONCLUSIONS: Taken together, compounds like MAL-A having pro-oxidant activity mediate their cytotoxicity in leukemic cells via induction of oxidative stress triggering a caspase dependent apoptosis

Synthesis, Characterisation, Structure, and Magnetic Properties of [Ni{H 2 NCH(CH 3 )CH 2 NH 2 } 3 ][Fe(CN) 5 NO]·H 2 O

The complex [Ni(pn

Berberine Chloride Mediates Its Anti-Leishmanial Activity via Differential Regulation of the Mitogen Activated Protein Kinase Pathway in Macrophages

BACKGROUND: A complex interplay between Leishmania and macrophages influences parasite survival and necessitates disruption of signaling molecules, eventually resulting in impairment of macrophage function. In this study, we demonstrate the immunomodulatory activity of Berberine chloride in Leishmania infected macrophages. PRINCIPAL FINDINGS: The IC(50) of Berberine chloride, a quaternary isoquinoline alkaloid was tested in an amastigote macrophage model and its safety index measured by a cell viability assay. It eliminated intracellular amastigotes, the IC(50) being 2.8 fold lower than its IC(50) in promastigotes (7.10 µM vs. 2.54 µM) and showed a safety index >16. Levels of intracellular and extracellular nitric oxide (NO) as measured by flow cytometry and Griess assay respectively showed that Berberine chloride in Leishmania infected macrophages increased production of NO. Measurement of the mRNA expression of iNOS, IL-12 and IL-10 by RT-PCR along with levels of IL-12p40 and IL-10 by ELISA showed that in infected macrophages, Berberine chloride enhanced expression of iNOS and IL-12p40, concomitant with a downregulation of IL-10. The phosphorylation status of extracellular signal related kinase (ERK1/2) and p38 mitogen activated protein kinase (p38 MAPK) was studied by western blotting. In infected macrophages, Berberine chloride caused a time dependent activation of p38 MAPK along with deactivation of ERK1/2; addition of a p38 MAPK inhibitor SB203580 inhibited the increased generation of NO and IL-12p40 by Berberine chloride as also prevented its decrease of IL-10. CONCLUSIONS: Berberine chloride modulated macrophage effector responses via the mitogen activated protein kinase (MAPK) pathway, highlighting the importance of MAPKs as an antiparasite target

A survey of ethnomedicinal plants of Darjeeling hills for their antimicrobial and antioxidant activities

479-492The aims of this study were to document ethnomedicinal knowledge of the tribes of Darjeeling hills and evaluate antimicrobial and antioxidant activities among the sampled plants. The study reports 78 plant species (47 families and 70 genera) from the three hilly sub-divisions of Darjeeling district. For antimicrobial evaluation, disc diffusion assay was used against a panel of 11 microorganisms (6 Gram positive bacteria species, 1 Gram negative bacteria species, 2 yeast species and 2 mould species). Antioxidant potential of the plants was investigated by assaying their total phenol content, total flavonoid content, DPPH·, <span style="font-family:Symbol;mso-ascii-font-family: " times="" new="" roman";mso-hansi-font-family:"times="" roman";mso-char-type:symbol;="" mso-symbol-font-family:symbol"="" lang="EN-GB">·OH and ABTS·+-scavenging activities, reducing power, metal-chelating activity and anti-lipid peroxidation activity. For statistical analysis, Pearson’s Chi Square test was used. Both PRTAU (plants with reports of traditional antimicrobial use) (40.3%) and PNRTAU (plants with no reports of traditional antimicrobial use) were equally active against the microorganisms tested. The <span style="font-family:Symbol; mso-ascii-font-family:" times="" new="" roman";mso-hansi-font-family:"times="" roman";="" mso-char-type:symbol;mso-symbol-font-family:symbol"="" lang="EN-GB">c2- test confirms that statistically there is a difference in count of PRTAU versus PNRTAU plants in different activity groups, indicating PRTAU plants have higher (P<0.05) probability (71.4% for PRTAU against 35.3% for PNRTAU) of showing lower MIC values than PNRTAU plants. In both the groups, plants displayed good antioxidant activities. </span