Disaster-Resilient Control Plane Design and Mapping in Software-Defined Networks

Communication networks, such as core optical networks, heavily depend on their physical infrastructure, and hence they are vulnerable to man-made disasters, such as Electromagnetic Pulse (EMP) or Weapons of Mass Destruction (WMD) attacks, as well as to natural disasters. Large-scale disasters may cause huge data loss and connectivity disruption in these networks. As our dependence on network services increases, the need for novel survivability methods to mitigate the effects of disasters on communication networks becomes a major concern. Software-Defined Networking (SDN), by centralizing control logic and separating it from physical equipment, facilitates network programmability and opens up new ways to design disaster-resilient networks. On the other hand, to fully exploit the potential of SDN, along with data-plane survivability, we also need to design the control plane to be resilient enough to survive network failures caused by disasters. Several distributed SDN controller architectures have been proposed to mitigate the risks of overload and failure, but they are optimized for limited faults without addressing the extent of large-scale disaster failures. For disaster resiliency of the control plane, we propose to design it as a virtual network, which can be solved using Virtual Network Mapping techniques. We select appropriate mapping of the controllers over the physical network such that the connectivity among the controllers (controller-to-controller) and between the switches to the controllers (switch-to-controllers) is not compromised by physical infrastructure failures caused by disasters. We formally model this disaster-aware control-plane design and mapping problem, and demonstrate a significant reduction in the disruption of controller-to-controller and switch-to-controller communication channels using our approach.Comment: 6 page

The use of Surface Enhanced Raman Spectroscopy (SERS) for biomedical applications

Recent advances in nanotechnology and the biotechnology revolution have created an immense opportunity for the use of noble metal nanoparticles as Surface Enhanced Raman Spectroscopy (SERS) substrates for biological sensing and diagnostics. This is because SERS enhances the intensity of the Raman scattered signal from an analyte by orders of 106 or more. This dissertation deals with the different aspects involved in the application of SERS for biosensing. It discusses initial studies performed using traditional chemically reduced silver colloidal nanoparticles for the SERS detection of a myriad of proteins and nucleic acids. It examines ways to circumvent the inherent aggregation problems associated with colloidal nanoparticles that frequently lead to poor data reproducibility. The different methods examined to create robust SERS substrates include the creation of thermally evaporated silver island films on microscope glass slides, using the technique of Nanosphere Lithography (NSL) to create hexagonally close packed periodic particle arrays of silver nanoparticles on glass substrates as well as the use of optically tunable gold nanoshell films on glass substrates. The three different types of SERS surfaces are characterized using UV-Vis absorption spectroscopy, Electron Microscopy (EM), Atomic Force Microscopy (AFM) as well as SERS using the model Raman active molecule trans-1,2-bis(4-pyridyl)ethylene (BPE). Also discussed is ongoing work in the initial stages of the development of a SERS based biosensor using gold nanoshell films for the direct detection of b-amyloid, the causative agent for Alzheimer's disease. Lastly, the use of gold nanoshells as SERS substrates for the intracellular detection of various biomolecules within mouse fibroblast cells in cell culture is discussed. The dissertation puts into perspective how this study can represent the first steps in the development of a robust gold nanoshell based SERS biosensor that can improve the ability to monitor biological processes in real time, thus providing new avenues for designing systems for the early diagnosis of diseases

Supply Chain Management Practices in Services Industry: An Empirical Investigation on Some Selected Services Sector of Bangladesh

The aim of this study is to examine the supply chain management practices in services industry of Bangladesh. Study revealed that there are differences in practices between manufacturing and services industry with few counts like inventory management, logistics management and use of technology etc. Within the selected sub-sectors, there are differences in the level of practices in supply chain management with banking sector is the highest whereas in hotel industry the practice is the lowest. This study also investigates the effect of supply chain responsiveness in terms of operation system responsiveness, logistic process responsiveness, supplier network responsiveness and competitive advantage of the firm. On the basis of findings, strategic supply chain management practices should be implemented in more detailed ways in services industry of Bangladesh

Influence of Dynamics of Actors and Information on the Organic Supply Chain

The agricultural sector throughout the world has seen shifting significantly by suitably using e-technology. A good number of studies have been conducted on agriculture and food security. The growth rate of world organic farming or business increases to more than the growth rate of traditional agriculture. In Bangladesh the pace of growth of organic agriculture is insignificant. The organic agriculture or organic supply chain in Bangladesh was scarcely studied. Hence, an intensive study is needed for the organic agriculture industry to pursue the organic supply chain that leads to a promising growth of organic business.  A great deal of research has been conducted to explore the factors that may influence the organic supply chain and growth of the organic business. Several theories such as the diffusion of innovation theory, theory of planned behavior, marketing system and price of organic products, and quality function deployment have been studied and proposed to enhance the understanding of the issue. The integration of all these literature and theories has attracted the researcher’s attention. Thus, this study aims to explore the influence of information systems, e-technology, and the dynamics of the actors (consumer, retailer, intermediaries, transporter, farmer, and basic suppliers) on the organic supply chain enhancing the growth of the organic business. By adopting secondary data with collected data (primary data) using self-administrated questionnaires the research work was evaluated. A total of 389 responses from the organic agriculture industrial actors, consumers, and transporters were collected using stratified random sampling methods. To inspect and analyze data, Path Analysis and Structural Equation Modeling (SEM) techniques were used with AMOS. The results of the study indicated that the proposed model provided a good understanding of the factors influencing the organic supply chain.  From the result, it was also revealed that the organic supply chain has a significant impact on the growth of organic farming and organic consumers and the performance of organic businesses. The research objectives of this study were accomplished and all research hypotheses were supported. This study theoretically offers useful information and collected data might help to further research relevant to the organic supply chain. In addition, the study finds a way to foster a better understanding and knowledge of the organic supply chain. It is encouraged to do future research to study the factors and information and impact of the organic supply chain from various aspects.Keywords: organic supply chain, e-technology, organic agriculture, growth of organic business, SEM, AMO

Effects of Black Cumin (Nigella sativa L.) on patients with cancer and tumor: A systematic Review

Experimental studies demonstrated a positive effect of administration of Nigella sativa L. (Back cumin) and its active chemical components on cancer and tumor through the antioxidant and anti-cancer activity. This study aimed to determine the beneficial effect of the use of black cumin in patients with cancer and tumor. This systematic review includes 4 randomized controlled trials that investigated the effect of the administration of black cumin in human cancer. Articles were searched in PubMed, Cochrane library, Semantic scholar and directory of open access journal (DOAJ), open grey and grey literature report databases for studies from 1983 to 2020 before May using the following keywords, Nigella sativa, black cumin, cancer, tumor, etc. The results examined that N. sativa is much effective in treating breast cancer, gastrointestinal cancer, brain tumor, and acute myeloid leukemia. According to the limited evidence from the study, black cumin may have favorable effects on cancer and tumor. However, more research is needed on different types of cancer to confirm and establish the above findings.

Rooftop gardening to improve food security in Dhaka city: A review of the present practices

In recent years, the trend of growing vegetables on green roofs has gained momentum as a way of promoting agricultural sustainability in Dhaka City. Rooftop gardens become an important part of urban agriculture's recent rejuvenation and offer alternative spaces for urban markets to grow vegetable products. Green roofs create spaces for vegetable crop production, thereby creating opportunities for agricultural incorporation into urban communities. At present, however, vegetable production activities on rooftops are limited due to multiple challenges that need to be addressed before widespread implementation takes place. Rooftop agriculture can improve various ecosystem services, enhance the biodiversity of urban areas and reduce food insecurity. Food production from green roofs will help support and sustain food for urban communities and provide a rare opportunity to grow food efficiently in typically unused spaces. As human populations become more urbanized and urban consumers become more interested in local food for their families, the use of alternative agricultural production systems, such as green roof technologies, will increase in importance. While cultivating food on buildings is a key component of making cities more sustainable and habitable, green roofs are not the total solution for providing cities with food security. They should be viewed more as a supplement to other sources of food production in urban areas

Prevalence of Staphylococcus aureus, Klebsiella spp., Escherichia coli and Pseudomonas spp. in some common Bangladeshi milk and dairy products

The study was done to isolate Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. from raw milk, processed milk (powdered milk & ultra-high-temperature milk) and dairy products (mango milk, and ice cream). During 3 months’ time span of study, a total of ten samples were gathered where eight of the samples powdered milk (2), ultra-high-temperature milk (2), ice cream (2) & mango milk (2) were gathered from different places of Bangladesh & other 2 samples (raw milk) were collected from a cattle farm & individual households in & around Noakhali city. The samples were gathered under aseptic safety measures and were followed by plating on non-selective media (Nutrient broth) & selective media (Mannitol Salt Agar & Macconkey agar). The presumptive Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. isolates were identified by biochemical tests. Analysis of the result discovered that out of a total of 10 samples; raw milk (2), processed milk i.e. powdered milk (2), ultra-high-temperature milk (2) and dairy products i.e. mango milk (2) and ice cream (2) resulted in the isolation of 8 isolates (2.5%) of S. aureus, (12.5%) of Klebsiella spp., (2.5%) of Pseudomonas spp. & (2.5%) of Escherichia coli. Results recommended a probability of potential public health threat of Staphylococcus aureus, Klebsiella spp., Escherichia coli & Pseudomonas spp. resulting from contamination of milk and dairy products with pathogenic microorganisms is mainly due to unhygienic practices and conditions in the handling, production, and processing

Christmas Disease (Hemophilia B) A Case Report

We report a 25 years old man developed Haemarthrosis of left hip joint with a history of recurrent swelling and pain in multiple joints and prolonged bleeding following minor trauma since childhood. Subsequent investigations revealed Christmas disease (Haemophilia B). Hemophilia B is an X-linked bleeding disorder. This case emphasises the importance of considering a diagnosis of haemophilia in a man with unexplained bleeding, even in the absence of a positive family history. DOI: 10.3329/bsmmuj.v2i2.4766 BSMMU J 2009; 2(2): 90-9

Suite of Meshless Algorithms for Accurate Computation of Soft Tissue Deformation for Surgical Simulation

The ability to predict patient-specific soft tissue deformations is key for computer-integrated surgery systems and the core enabling technology for a new era of personalized medicine. Element-Free Galerkin (EFG) methods are better suited for solving soft tissue deformation problems than the finite element method (FEM) due to their capability of handling large deformation while also eliminating the necessity of creating a complex predefined mesh. Nevertheless, meshless methods based on EFG formulation, exhibit three major limitations: i) meshless shape functions using higher order basis cannot always be computed for arbitrarily distributed nodes (irregular node placement is crucial for facilitating automated discretization of complex geometries); ii) imposition of the Essential Boundary Conditions (EBC) is not straightforward; and, iii) numerical (Gauss) integration in space is not exact as meshless shape functions are not polynomial. This paper presents a suite of Meshless Total Lagrangian Explicit Dynamics (MTLED) algorithms incorporating a Modified Moving Least Squares (MMLS) method for interpolating scattered data both for visualization and for numerical computations of soft tissue deformation, a novel way of imposing EBC for explicit time integration, and an adaptive numerical integration procedure within the Meshless Total Lagrangian Explicit Dynamics algorithm. The appropriateness and effectiveness of the proposed methods is demonstrated using comparisons with the established non-linear procedures from commercial finite element software ABAQUS and experiments with very large deformations. To demonstrate the translational benefits of MTLED we also present a realistic brain-shift computation.Comment: Accepted for publication in Medical Image Analysi