An efficient high-order Nystr\"om scheme for acoustic scattering by inhomogeneous penetrable media with discontinuous material interface

This text proposes a fast, rapidly convergent Nystr\"{o}m method for the solution of the Lippmann-Schwinger integral equation that mathematically models the scattering of time-harmonic acoustic waves by inhomogeneous obstacles, while allowing the material properties to jump across the interface. The method works with overlapping coordinate charts as a description of the given scatterer. In particular, it employs "partitions of unity" to simplify the implementation of high-order quadratures along with suitable changes of parametric variables to analytically resolve the singularities present in the integral operator to achieve desired accuracies in approximations. To deal with the discontinuous material interface in a high-order manner, a specialized quadrature is used in the boundary region. The approach further utilizes an FFT based strategy that uses equivalent source approximations to accelerate the evaluation of large number of interactions that arise in the approximation of the volumetric integral operator and thus achieves a reduced computational complexity of $O(N \log N)$ for an $N$-point discretization. A detailed discussion on the solution methodology along with a variety of numerical experiments to exemplify its performance in terms of both speed and accuracy are presented in this paper

Concordance between decision analysis and matching systematic review of randomized controlled trials in assessment of treatment comparisons: a systematic review

BACKGROUND: Systematic review (SR) of randomized controlled trials (RCT) is the gold standard for informing treatment choice. Decision analyses (DA) also play an important role in informing health care decisions. It is unknown how often the results of DA and matching SR of RCTs are in concordance. We assessed whether the results of DA are in concordance with SR of RCTs matched on patient population, intervention, control, and outcomes. METHODS: We searched PubMed up to 2008 for DAs comparing at least two interventions followed by matching SRs of RCTs. Data were extracted on patient population, intervention, control, and outcomes from DAs and matching SRs of RCTs. Data extraction from DAs was done by one reviewer and from SR of RCTs by two independent reviewers. RESULTS: We identified 28 DAs representing 37 comparisons for which we found matching SR of RCTs. Results of the DAs and SRs of RCTs were in concordance in 73% (27/37) of cases. The sensitivity analyses conducted in either DA or SR of RCTs did not impact the concordance. Use of single (4/37) versus multiple data source (33/37) in design of DA model was statistically significantly associated with concordance between DA and SR of RCTs. CONCLUSIONS: Our findings illustrate the high concordance of current DA models compared with SR of RCTs. It is shown previously that there is 50% concordance between DA and matching single RCT. Our study showing the concordance of 73% between DA and matching SR of RCTs underlines the importance of totality of evidence (i.e. SR of RCTs) in the design of DA models and in general medical decision-making

Functional significance of unique sequences in Mycobaterium smegmatis Ku proteins

Ku is central to the non-homologous end-joining pathway of DNA double strand break repair, first discovered in eukaryotes and more recently in prokaryotes and archaea. This study concerns the importance of two unique sequence features of Ku protein from Mycobacterium smegmatis that include a lysine-rich extension at the C-terminus and a zinc-binding motif in the DNA-binding bridge-region. The unique C-terminal tail of M. smegmatis Ku contains several lysine-rich low-complexity PAKKA repeats that are absent from homologs encoded by obligate parasitic mycobacteria, but present in other mycobacterial proteins such as histone-like proteins. Removal of the lysine-rich extension from Ku decreased thermal stability and abolished DNA end-joining. The tail contacts the core DNA binding domain of Ku and hinders DNA-protein interaction as evidenced by an increase in DNA binding affinity upon removal of the lysine-rich extension. In contrast to Ku lacking the C-terminus, full-length Ku can directly bind DNA without free ends and form multiple complexes with a short stem-loop-containing DNA previously designed to accommodate only one Ku dimer, suggesting that these properties are conferred by its C-terminus. My study suggests that low-complexity lysine-rich sequences have evolved repeatedly to modulate the function of unrelated DNA-binding proteins and that extensions beyond the shared core domain may have independently evolved to expand Ku function. An in vitro metal binding assay showed zinc binding to a predicted zinc-binding motif in the bridge-region of M. smegmatis Ku, an event that stabilizes the protein and prevents cysteine oxidation, but has little effect on DNA binding. In vivo, zinc induced significant upregulation of the gene encoding Ku as well as a divergently oriented gene encoding a predicted zinc-dependent MarR family transcription factor. In addition, overexpression of Ku conferred zinc tolerance on E. coli. I speculate that zinc binding sites in Ku proteins from M. smegmatis and other mycobacterial species have been evolutionarily retained to provide protection against zinc toxicity. In all, my study identifies novel properties conferred by unique sequences present in M. smegmatis Ku protein, which suggests that the retention and evolution of unique sequences within a protein provides an adaptive advantage to microorganisms against environmental stress

Indian Mythology and Ecocriticism

According to Indian philosophy, human body is said to be formed of five elements – Panchtattva, namely earth (prithvi), water (apas), fire (agni), air (vayu) and aether (akasha). From the birth of an individual till his death, the Indian way of life is closely connected to nature. From home hearths to the funeral pyres, wood and fire are predominantly present. A newborn is consecrated with the holy waters of Ganges and the ashes of the dead are immersed in the same holy water. Indians have long had an intense connection with nature. This connection is clearly reflected in the Indian mythology. The two major Indian epics, Ramayana and Mahabharata, present nature in its various manifestations presenting it sometimes as a saviour, sometimes a protector and many times as a pioneer. The connection between Indian mythology and nature becomes conspicuous when we come across characters like Bhumija Sita, Suryaputra Karna, Vayuputra Hanumana and Shakuntala (the nature’s child) who is born and brought up in the lap of nature and whose beauty and innocence are as pure as nature itself. These writings and characters have deeply impacted the Indian psyche through ages. This paper will study such connection between Indian mythology and environment in detail and analyse how Indian mythology has contributed in preserving the nature keeping in mind the concept of eco-criticism

Application Specific Secure Grouping of Vehicles in Vehicular Ad-hoc Network

Providing efficient, secure and reliable communication among vehicles is complicated and challenging problem. Vehicles communicate with each other (V2V communication) and Road Side Infrastructure (V2X communication) unit to provide convenient, safety and commercial service to the travelers. Similar information shared by each vehicle within close proximity creates huge network congestion. Grouping of vehicles reduces dropping of packets due to collision of sending large number of duplicate packets. Grouping concept is used in our thesis to provide different applications of VANET in a better way. We have modified grouping of vehicles according to our applications requirement and proposed an approach for vehicles to select real-time adaptive path. Vehicles choose congestion free and shortest time path to their destination. In the next section, grouping of vehicles are used to transmit event-driven safety message in emergency situations. Grouping of vehicles is efficient in this case as it needed to be very fast and highly reliable. We have added different parameters for transmitting the message to neighbors which makes it more efficient. It uses decentralized environment as it needed to works both for highway and urban scenario of the city. It helps to improve security in the message and privacy of entities in an efficient manner which are major concern in achieving robust vehicular network. In testing phase, we evaluated the performance of our proposed approach with help of VANET simulators (OMNET++, SUMO, Veins) and compared ours proposed approach with other existing methods

Human Machine Interface for Controlling a Robot Using Image Processing

This paper introduces a head movement based Human Machine Interface (HMI) that uses the right and left movements of head to control a robot motion. Here we present an approach for making an effective technique for real-time face orientation information system, to control a robot which can be efficiently used for Electrical Powered Wheelchair (EPW). Basically this project aims at application related to HMI. The system (machine) identifies the orientation of the face movement with respect to the pixel values of image in a certain areas. Initially we take an image and divide that whole image into three parts on the basis of its number of columns. On the basis of orientation of face, maximum pixel value of approximate same range of (R, G, and B value of a pixel) lie in one of divided parts of image. This information we transfer to the microcontroller through serial communication port and control the motion of robot like forward motion, left and right turn and stop in real time by using head movements