Search

Abstract Disease recurrence following chemotherapy is a major clinical challenge in ovarian cancer (OC), but little is known regarding how the tumour epigenome regulates transcriptional programs underpinning chemoresistance. We determine the single cell chromatin accessibility landscape of omental OC metastasis from treatment-naïve and neoadjuvant chemotherapy-treated patients and define the chromatin accessibility profiles of epithelial, fibroblast, myeloid and lymphoid cells. Epithelial tumour cells display open chromatin regions enriched with motifs for the oncogenic transcription factors MEIS and PBX. Post chemotherapy microenvironments show profound tumour heterogeneity and selection for cells with accessible chromatin enriched for TP53, TP63, TWIST1 and resistance-pathway-activating transcription factor binding motifs. An OC chemoresistant tumour subpopulation known to be present prior to treatment, and characterised by stress-associated gene expression, is enriched post chemotherapy. Nuclear receptors RORa, NR2F6 and HNF4G are uncovered as candidate transcriptional drivers of these cells whilst closure of binding sites for E2F2 and E2F4 indicate post-treated tumour having low proliferative capacity. Delineation of the gene regulatory landscape of ovarian cancer cells surviving chemotherapy treatment therefore reveals potential core transcriptional regulators of chemoresistance, suggesting novel therapeutic targets for improving clinical outcome.

Besides being chief construction ingredients, concrete and steel produce a high amount of CO2, and high energy consumption promotes global warming. To evade this problem, green and low energy consuming alternative is required. Rapid growing time with the least period to attend optimum strength made bamboo a new immerging mainstream constituent in construction. Bamboo, as one of the probable alternate structural materials, not only promises a sustainable and sturdy option but also reduces the environmental carbon footprint. In this research, article authors replaced steel reinforcement in concrete with bamboo. To establish bamboo as a construction material, a concrete beam of 200 mm × 500 mm is made in which bamboo bars of diameter 20 mm are used with a variation of 1 to 4% of the reinforcement area. Various tests were performed to provide the feasibility of bamboo as construction materials after 28 days of curing, in which test results were found promising. The impact test shows only 25% of wear and tear. Also, bamboo reinforced concrete (BRC) without changing cross sections provided 50% axial compressive strength compared to steel reinforced concrete (SRC). However, in the tensile test, BRC outperformed SRC by providing 50% more resistance against tensile load. Authors also performed rate analysis between SRC and BRC to find that it almost reduces 18% of the cost at a small scale. Hence here, comparative research is provided, and the authors believe that it would pave the road on which forthcoming researchers will walk to reach the destination of finding an alternate, sustainable, and green construction material in the form of bamboo.

Abstract The present work demonstrates the impact of thermal annealing on the structural, linear, and non-linear optical characteristics of thermally evaporated BixIn35-xSe65 (x = 0, 5, 10, 15 at%) thin films. The prominent crystalline phases have been developed for all annealed films at 450 °C whereas the films remain amorphous at 350 °C annealing. The XRD and Raman analysis showed the phase transformation of Bi-doped films and new Bi2Se3 phases developed upon annealing at 450 °C. The phase transformation induced change increased the linear and nonlinear properties with great extent as seen from the UV–visible optical studies. The direct and indirect optical bandgaps decreased with annealing temperature and also with Bi % content due to the formation of surface dangling bonds near the crystallite sites. The static linear refractive index and high-frequency dielectric constants were increased with annealing. The third-order non-linear susceptibility and non-linear refractive index were found to be greatly influenced by annealing temperature and increased with bismuth content. The FESEM micrographs also showed the phase transformation and EDX analysis showed the composition. The results obtained from the materials showed the potentiality to be useful for photovoltaic and optoelectronic applications.

Forest canopies have been dubbed the last biological frontier and continue to remain underexplored. Vascular epiphytes form a rich assemblage of plants within the forest canopy and apart from sustaining diverse taxa, they also fulfill critical ecological functions. Vascular epiphytes are particularly sensitive to perturbations of microclimate and microhabitat within the canopy, especially from anthropogenic changes such as logging. The forests of the megadiverse Western Ghats in India harbor a rich assemblage of vascular epiphytes, but their ecology has not been examined systematically. We compared the diversity, abundance, and composition of a vascular epiphyte assemblage between an unlogged and a historically selectively logged forest in the southern Western Ghats, India, and identified factors affecting the epiphyte assemblage. Canopies of 100 trees each in selectively logged and unlogged forests were accessed using the single-rope technique. We found 20 species of vascular epiphytes with the assemblage dominated by members of Orchidaceae. The diversity and abundance of epiphytes were significantly greater in the selectively logged forest. One host tree, Cullenia exarillata, supported the greatest number of epiphytes in both forest stands. The niche widths of epiphyte species, computed with host tree species as a resource, were similar between the two stands but a greater number of species pairs overlapped in the selectively logged forest. Overall, epiphyte abundance was negatively associated with unlogged forests. Host tree species, tree height, and presence of moss on branches were positively associated with the abundance of epiphytes. Despite being ecologically important, no study has thus far examined the impact of selective logging on the epiphyte assemblage in the Western Ghats. Our findings contribute to the knowledge of vascular epiphytes from South and Southeast Asia and set the stage for future research and conservation.

Providing service guarantees for real time applications like voice and video are key concerns in WiMAX (IEEE802.16) networks. Proper resource management with the help of an appropriate packet scheduling algorithm achieves the required service guarantee. Scheduling algorithm determines the order of packet delivery among many packets which are waiting to be serviced from the queue. This paper enhances the Modified Low Latency Queuing (MLLQ) algorithm to improve the Quality of Service (QoS) and to ensure service guarantee for real time applications. We propose an Adaptive MLLQ (AMLLQ) algorithm as an extension of the work done in the MLLQ. The MLLQ algorithm introduced an additional Strict Priority Queue (SPQ) in the LLQ to improve the QoS for video applications. The AMLLQ algorithm determines the order of scheduling between the two SPQs dynamically by considering the queue size. The SPQ which exceeds the queue threshold will be processed preferentially than the other SPQ. Simulation results show that the AMLLQ outperforms the MLLQ with respect to throughput and delay for the real time applications.

Abstract We present our angle resolved photoelectron spectroscopy (ARPES) and density functional theory results on quaternary topological insulator (TI) BiSbTe1.25Se1.75 (BSTS) confirming the non-trivial topology of the surface state bands (SSBs) in this compound. We find that the SSBs, which are are sensitive to the atomic composition of the terminating surface have a partial 3D character. Our detailed study of the band bending (BB) effects shows that in BSTS the Dirac point (DP) shifts by more than two times compared to that in Bi2Se3 to reach the saturation. The stronger BB in BSTS could be due to the difference in screening of the surface charges. From momentum density curves (MDCs) of the ARPES data we obtained an energy dispersion relation showing the warping strength of the Fermi surface in BSTS to be intermediate between those found in Bi2Se3 and Bi2Te3 and also to be tunable by controlling the ratio of chalcogen/pnictogen atoms. Our experiments also reveal that the nature of the BB effects are highly sensitive to the exposure of the fresh surface to various gas species. These findings have important implications in the tuning of DP in TIs for technological applications.

Cloud computing has revolutionized the IT industry by offering huge storage for data outsourcing and also for computation. Various security issues concerned with security and privacy of data arise in the context of data outsourcing. The framework enables clients to outsource encrypted data to the cloud, enables users to retrieve preferred documents using multiple keywords and allows the user to verify the response from the server. The strength of the proposed model relies on the discrete logarithmic problem of Hyper Elliptic Curve Cryptography (HECC) and the security of Merkle trees. The paper proposes a user verifiable multi-keyword search scheme, which focuses on: (i) construction of inverted index for the documents with keywords; (ii) index and document encryption by HECC; (iii) index and document authentication by the Merkle tree; and (iv) verification of the accuracy of response from server by top hash or root hash value of the Merkle tree. Security analysis and results demonstrate the correctness of proposed multiple keyword search (MKS) scheme. The search algorithm combined with the hash value verification process by the Merkle tree is strong enough to provide data security, privacy, and integrity. The proposed model reduces the storage overhead on both the client’s and user’s side. As the number of documents increases, the retrieval time is less, which reduces the storage overhead on both sides.

This work reports the formation of topological Bi2Se3 phase upon annealing higher % of Bi content in amorphous As40Se60-xBix (x = 2, 7, 10 and 15%) chalcogenide thin films prepared by thermal evaporation process. The phase identification was done by X-ray diffraction study and Field emission scanning electron microscopy studies confirm the phase transformation in As40Se45Bi15 thin film. The Raman measurements indicated the formation of crystalline As4Se4 and Bi2Se3 phase with annealing at 473K and the indirect optical band gap were found to decrease with increase in Bi concentration on thermal annealing as probed from the optical measurement. The changes in optical parameters were described on the basis of the density of localized states and the electrical resistance was found to be decreased which has been measured at room temperature by using the two-point probe technique.

In recent times, the demand for the real time audio and video applications in wireless networks is very high due to widespread use of latest wireless communication technologies. Many of these applications require different Quality of Service (QoS) in terms of delay and throughput in the resource constrained wireless networks. In order to handle the resources effectively and to increase the QoS, proper packet scheduling algorithms need to be developed. Low-latency Queuing (LLQ) is a packet scheduling algorithm which combines Strict Priority Queuing (SPQ) to Class-Based Weighted Fair Queuing (CB-WFQ). LLQ places delay sensitive applications such as voice and video in the SPQ and treat them preferentially over other traffic by allowing the application to be processed and sent first from the SPQ. In this paper, an Enhanced LLQ (ELLQ) is proposed. An additional SPQ is introduced for scheduling the video applications separately along with the dedicated SPQ for voice applications. The performance of the proposed algorithm is compared with other existing algorithms through simulations using the OPNET modeler. Simulation and Statistical results show that the proposed algorithm has given 1.5 times performance improvement in terms of throughput and delay than the existing algorithms for the real time audio and video applications.

The low-cost Wireless Sensor Network (WSN) consists of small battery powered devices called sensors, with limited energy capacity. Once deployed, accessibility to any sensor node for maintenance and battery replacement is not feasible due to the spatial scattering of the nodes. This will lead to an unreliable, limited lifetime and a poor connectivity network. In this paper a novel bio-inspired cluster-based deployment algorithm is proposed for energy optimization of the WSN and ultimately to improve the network lifetime. In the cluster initialization phase, a single cluster is formed with a single cluster head at the center of the sensing terrain. The second phase is for optimum cluster formation surrounding the inner cluster, based on swarming bees and a piping technique. Each cluster member distributes its data to its corresponding cluster head and the cluster head communicates with the base station, which reduces the communication distance of each node. The simulation results show that, when compared with other clustering algorithms, the proposed algorithm can significantly reduce the number of clusters by 38% and improve the network lifetime by a factor of 1/4.

The performance analysis of Hyperelliptic Curve Cryptosystems (HECC) over prime fields (Fp) of genus 5 and 6 are discussed in this paper. We have implemented a HECC system of genus 5 & 6 in a Intel Pentium III Celeron Processor @ 933 MHz speed with 256 MB RAM in Java 1.5. We have also compared their efficiency on the parameters of time taken for divisor generation, key generation, encryption and decryption. Our results demonstrate that the performance of higher genus HECC system gets degraded in terms of divisor generation, key generation, encryption and decryption process.