The physicochemical properties of saliva, such as pH, buffering capacity, calcium, phosphorous, amylase and Streptococcus mutans has a definite relationship with caries activity.

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An approximate membership query data structure (AMQ)-such as a Bloom, quotient, or cuckoo filter-maintains a compact, probabilistic representation of a set S of keys from a universe U. It supports lookups and inserts. Some AMQs also support deletes. A query for x ∈ S returns PRESENT. A query for x ∈ S returns PRESENT with a tunable false-positive probability ε, and otherwise returns ABSENT.AMQs are widely used to speed up dictionaries that are stored remotely (e.g., on disk or across a network). The AMQ is stored locally (e.g., in memory). The remote dictionary is only accessed when the AMQ returns PRESENT. Thus, the primary performance metric of an AMQ is how often it returns ABSENT for negative queries.Existing AMQs offer weak guarantees on the number of false positives in a sequence of queries. The false-positive probability ε holds only for a single query. It is easy for an adversary to drive an AMQ's false-positive rate towards 1 by simply repeating false positives.This paper shows what it takes to get strong guarantees on the number of false positives. We say that an AMQ is adaptive if it guarantees a false-positive probability of ε for every query, regardless of answers to previous queries.We establish upper and lower bounds for adaptive AMQs. Our lower bound shows that it is impossible to build a small adaptive AMQ, even when the AMQ is immediately told whenever a query is a false positive. On the other hand, we show that it is possible to maintain an AMQ that uses the same amount of local space as a non-adaptive AMQ (up to lower order terms), performs all queries and updates in constant time, and guarantees that each negative query to the dictionary accesses remote storage with probability ε, independent of the results of past queries. Thus, we show that adaptivity can be achieved effectively for free.

Leukocytes have ability to distinguish between self cells (body own cells) and foreign (allogenic) cells on the basis of human leukocyte antigen (HLA) proteins that are present on the cell membrane and are effectively unique to a person. During allogenic blood transfusion a person receives large number of allogenic donor leukocytes and these are recognized as foreign cells by the recipient immune system which leads to several adverse reactions. To avoid such leukocyte-mediated adverse reactions leukodepleted blood transfusion is required. Leukocytes can be separated on the basis of size, dielectric properties, by affinity separation, freeze-thawing and centrifugation but all these methods are time consuming and costly. Filtration is another method for leukocyte depletion that is comparatively less expensive and more efficient as it gives more than 90% leukodepletion of blood along with minimal cell loss. However, present filtration procedures also have some limitations as they work efficiently with blood components but not with whole blood and show non-specific adhesion of large number of platelets and red blood cells along with leukocytes. All the currently available filters are costly, which has been a major reason for their limited application. Therefore, demand for a more efficient and cost-effective filter is high in medical community and scientists are attenpting to improve the efficiency of currently available filters. The present review gives an overview of the significance of leukodepleted blood transfusion and focuses on different methods for leukocyte depletion and challenges involved in all these technologies.

Interactive proofs (IP) model a world where a verifier delegates computation to an untrustworthy prover, verifying the prover's claims before accepting them. IP protocols have applications in areas such as verifiable computation outsourcing, computation delegation, cloud computing, etc. In these applications, the verifier may pay the prover based on the quality of his work. Rational interactive proofs (RIP), introduced by Azar and Micali (2012), are an interactive-proof system with payments, in which the prover is rational rather than untrustworthy-he may lie, but only to increase his payment. Rational proofs leverage the prover's rationality to obtain simple and efficient protocols. Azar and Micali show that RIP=IP(=PSPACE), i.e., the set of provable languages stay the same with a single rational prover (compared to classic IP). They leave the question of whether multiple provers are more powerful than a single prover for rational and classical proofs as an open problem.In this paper we introduce multi-prover rational interactive proofs (MRIP). Here, a verifier cross-checks the provers' answers with each other and pays them according to the messages exchanged. The provers are cooperative and maximize their total expected payment if and only if the verifier learns the correct answer to the problem. We further refine the model of MRIP to incorporate utility gaps, which is the loss in payment suffered by provers who mislead the verifier to the wrong answer.We define the class of MRIP protocols with constant, noticeable and negligible utility gaps-the payment loss due to a wrong answer is O(1), 1/n O(1) and 1/2 n O(1) respectively, where n is the length of the input. We give tight characterization for all three MRIP classes. On the way, we resolve Azar and Micali's open problem-under standard complexity-theoretic assumptions, MRIP is not only more powerful than RIP, but also more powerful than MIP (classic multi-prover IP); and this is true even the utility gap is required to be constant. We further show that the full power of each MRIP class can be achieved using only two provers and three rounds of communication.