Atomic Batteries: Energy from Radioactivity

With alternate, sustainable, natural sources of energy being sought after, there is new interest in energy from radioactivity, including natural and waste radioactive materials. A study of various atomic batteries is presented with perspectives of development and comparisons of performance parameters and cost. We discuss radioisotope thermal generators, indirect conversion batteries, direct conversion batteries, and direct charge batteries. We qualitatively describe their principles of operation and their applications. We project possible market trends through our comparative cost analysis. We also explore a future direction for certain atomic batteries by using nanomaterials to improve their performance.Comment: review; v2 with corrected tex

A Distortion Based Approach for Protecting Inferences

Eavesdropping attacks in inference systems aim to learn not the raw data, but the system inferences to predict and manipulate system actions. We argue that conventional information security measures can be ambiguous on the adversary's estimation abilities, and adopt instead a distortion based framework that enables to operate over a metric space. We show that requiring perfect distortion-based security is more frugal than requiring perfect information-theoretic secrecy even for block length one codes, offering in some cases unbounded gains. Within this framework, we design algorithms that enable to efficiently use shared randomness, and show that each bit of shared random key is exponentially useful in security

On the Oblivious Transfer Capacity of the Degraded Wiretapped Binary Erasure Channel

We study oblivious transfer (OT) between Alice and Bob in the presence of an eavesdropper Eve over a degraded wiretapped binary erasure channel from Alice to Bob and Eve. In addition to the privacy goals of oblivious transfer between Alice and Bob, we require privacy of Alice and Bob's private data from Eve. In previous work we derived the OT capacity (in the honest-but-curious model) of the wiretapped binary independent erasure channel where the erasure processes of Bob and Eve are independent. Here we derive a lower bound on the OT capacity in the same secrecy model when the wiretapped binary erasure channel is degraded in favour of Bob.Comment: To be presented at the IEEE International Symposium on Information Theory (ISIT 2015), Hong Kon

The Oblivious Transfer Capacity of the Wiretapped Binary Erasure Channel

We consider oblivious transfer between Alice and Bob in the presence of an eavesdropper Eve when there is a broadcast channel from Alice to Bob and Eve. In addition to the secrecy constraints of Alice and Bob, Eve should not learn the private data of Alice and Bob. When the broadcast channel consists of two independent binary erasure channels, we derive the oblivious transfer capacity for both 2-privacy (where the eavesdropper may collude with either party) and 1-privacy (where there are no collusions).Comment: This is an extended version of the paper "The Oblivious Transfer Capacity of the Wiretapped Binary Erasure Channel" to be presented at ISIT 201

Fluoride - an adjunctive therapeutic agent for periodontal disease? Evidence from a cross-sectional study

Objective: To assess the influence of the water fluoride level on periodontal status, by determining the periodontal health status of subjects residing in low, optimum and high fluoride areas. Study design: A cross sectional survey was carried out on 967 adults aged 35-44 years old, from the Udaipur district of India. A stratified cluster random sampling technique was implemented in order to collect a representative sample from low (3ppm) areas, based on the fluoride concentration in drinking water. Periodontal status was assessed in accordance to WHO criteria. The Chi-square test was used to compare proportions, and logistic regression analysis was used to determine the contribution of water fluoride levels to periodontal disease. Results: Those residing in areas of low fluoride levels were more likely to present periodontal pockets than those living in high fluoride areas 1.3 (95 % CI 1.11±1.86). Subjects living in areas of low fluoride were noted to have a higher risk of periodontal attachment loss of more than 8mm (OR = 1.94, 95% CI 1.67±3.85). The risk for presence of periodontal pockets and attachment loss of more than 8mm increased by 1.17 (95 % CI 1.02±1.69) and 1.59 (95 % CI 1.27±3.29) respectively for those residing in areas of optimum fluoride levels. Deep periodontal pockets were more prevalent (6.3%) among those residing in areas of low fluoride, followed by optimum (5.2%) and high (3.1%). Conclusions: As the fluoride concentrations increased, the prevalence of shallow and deep periodontal pockets decreased. The severity of periodontal disease was significantly associated with fluoride levels, with cases of loss of attachment gradually decreasing when moving from low fluoride areas to high fluoride areas. It appears that longitudinal studies need to be conducted in order to ascertain the benefits; and microbiological analysis of dental plaque and periodontium should be carried out in order to confirm the effects of fluoride on periodontal conditions