A Survey on Secret Key Extraction Using Received Signal Strength in Wireless Networks

Secure wireless communications typically rely on secret keys, which are difficult to establish in an ad hoc network without a key management infrastructure. The channel reciprocity and spatial decorrelation properties can be used to extract secret key, especially in a Rayleigh fading channel. But the intervention of intermediate objects between the communication nodes reduces the strength of the secret key generated through such methods. Furthermore, the impact of small fluctuations also reduces the bit matching rate of such key agreement methods. This paper is based on the survey conducted on secret key generation from Received Signal Strength (RSS). By consider ing uniqueness property of RSS as base, various authors have proposed different methods for secret key extraction. Due to use of RSS for key extraction the existing systems suffer from predictable filter response at random period. The existing system also faces signal fading and drop in RSS because of intermediate object. By this survey we specify that even after generating high entropy bits for key extraction, there are considerable drawbacks in extracted key du e to intervention of intermediate objects and remarkable fading and drop in RSS

Biotechnological Perspective of Reactive Oxygen Species (ROS)-Mediated Stress Tolerance in Plants

All environmental cues lead to develop secondary stress conditions like osmotic and oxidative stress conditions that reduces average crop yields by more than 50% every year. The univalent reduction of molecular oxygen (O2) in metabolic reactions consequently produces superoxide anions (O2•−) and other reactive oxygen species (ROS) ubiquitously in all compartments of the cell that disturbs redox potential and causes threat to cellular organelles. The production of ROS further increases under stress conditions and especially in combination with high light intensity. Plants have evolved different strategies to minimize the accumulation of excess ROS like avoidance mechanisms such as physiological adaptation, efficient photosystems such as C4 or CAM metabolism and scavenging mechanisms through production of antioxidants and antioxidative enzymes. Ascorbate-glutathione pathway plays an important role in detoxifying excess ROS in plant cells, which includes superoxide dismutase (SOD) and ascorbate peroxidase (APX) in detoxifying O2•−radical and hydrogen peroxide (H2O2) respectively, monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) involved in recycling of reduced substrates such as ascorbate and glutathione. Efficient ROS management is one of the strategies used by tolerant plants to survive and perform cellular activities under stress conditions. The present chapter describes different sites of ROS generation and and their consequences under abiotic stress conditions and also described the approaches to overcome oxidative stress through genomics and genetic engineering

Prevalence of self-care practices and assessment of their sociodemographic risk factors among diabetes in the urban slums of Bengaluru

Objective: The objective of this study was to determine the prevalence of self-care practices in the urban slums of Bengaluru among diabetes and also to assess their sociodemographic risk factors. Materials and Methods: A cross-sectional study was done in the two slums of Bengaluru comprising 163 diabetes patients. The prevalence of self-care practices and their sociodemographic risk was analyzed. Results: Maximum adherence was seen for blood sugar testing (77.91%), and least adherence was seen for diet (12.26%). Adherence to exercise was 30.67%, adherence to foot care was 48.46%, and adherence to medication was 60.73%. Some of the sociodemographic factors associated with good self-care practices are young age, gender, formal education, occupation, and religion. Good adherence to medication is associated with better control of blood sugars. Conclusion: A clinician should be able to identify these risk factors and give special attention to these groups of patients and make realistic recommendations for self-care activities

Variation of the donor and acceptor in D-A-pi-A based cyanopyridine dyes and its effect on dye sensitized solar cells

Two metal free organic dyes (TPCTh and TPCRh) with D-A-pi-A configuration, having 3-cyanopyridine as an auxiliary acceptor and thiophene pi-linkers along with a triphenylamine donor and cyanoacetic acid/rhodanine-3-acetic acid anchoring groups, were successfully synthesized and utilized as sensitizers in the fabrication of dye-sensitized solar cells (DSSCs). The opto-electronic properties of TPCTh and TPCRh were compared with the model sensitizer CCTh having carbazole as the donor and cyanoacetic acid as the anchoring group. Both the dyes showed red shifted absorption spectra compared to the standard CCTh dye. Also, TPCRh showed a broader absorption spectrum with a reduced band gap compared to TPCTh. However, theoretical studies indicate that the unavailability of excited state conjugation over the anchoring group could lead to restricted charge injection for the TPCRh dye, whereas the TPCTh dye exhibits complete conjugation over the entire molecule. The photovoltaic performance of the TPCTh dye was found to be better compared with the standard CCTh sensitizer as a result of better absorption contributed by the lower band gap in TPCTh leading to improved photon-light conversion and thus an improved J(sc) of 11 mA cm(-2) over the 7.12 mA cm(-2) of CCTh. In addition, lifetime measurements corroborated a lower electron lifetime for TPCRh compared to TPCTh and CCTh