Abstract

Silent information regulator 2 (Sir2), the founding member of the conserved sirtuin family of NAD+-dependent histone deacetylase, regulates several physiological processes including genome stability, gene silencing, metabolism and life span in yeast. Within the nucleus, Sir2 is associated with telomere clusters in the nuclear periphery and rDNA in the nucleolus and regulates gene silencing at these genomic sites. How distribution of Sir2 between telomere and rDNA is regulated is not known. Here we show that Sir2 is sumoylated and this modification modulates the intra-nuclear distribution of Sir2. We identify Siz2 as the key SUMO ligase and show that multiple lysines in Sir2 are subject to this sumoylation activity. Mutating K215 alone counteracts the inhibitory effect of Siz2 on telomeric silencing. SUMO modification of Sir2 impairs interaction with Sir4 but not Net1 and, furthermore, SUMO modified Sir2 shows …

Abstract

The laboratory is an indispensable component of learning in engineering education. In this paper, we examine the impact of Advanced VLSI Virtual Lab, which is a part of the Government of India's suite of Virtual Labs, in improving the understanding and learning of students at a small sized university in India. The Advanced VLSI Virtual Lab includes ten simulated interactive experiments in the area of design and application development. Over a hundred Virtual Labs have been proposed and built, but, so far, few have been subject to systematic investigation of their effectiveness in helping the student learn. Our work is one of the first efforts to statistically study the effectiveness of the Virtual Lab. To this end, we designed and conducted pre- and post-tests, and feedback surveys on the lab. The tests and the survey, on analysis, reveal that the lab is effective in enhancing student learning. Our results are encouraging to …

Abstract

Generation of problem sets and quizzes forms an important part of education technologies. Although some systems have been built for quiz generation, they mostly focus on abstract logic and mathematical constructs. Knowledge in other domains is relational rather than propositional, and many systems use dedicated knowledge databases. We present a method to present this knowledge in the form of objective question sets and drills. We implement a four-fold approach - ontologies, propositional logic, similarity finding, and hierarchies - as a way to generate quizzes as well as to solve human generated problems of a similar nature. The architecture of this system is such that any knowledgebase can be turned into a vast number of diverse, complex questions. We build this system for an ontology of North Indian Ragas, and also test it on a smaller ontology of animals. We demonstrate an approach to solving human

Abstract

In CMOS radio frequency integrated circuits, inductors are a barrier in achieving better monolithic solutions because of the large area occupied and the associated parasitics. For better performance of on-chip inductors, soft magnetic materials are incorporated with them. In an earlier work, it was shown that by tailoring the shape and size of the permalloy patterns, formation of magnetic domains can be controlled. When such domain patterns are incorporated with inductors, they have varied effects on inductor performance. In this paper, it is demonstrated that by depositing 60 nm thick domain-controlled permalloy patterns, better performance of inductors can be obtained at higher frequencies (>5 GHz). About 2× increment in inductance and 7× increment in quality factor is obtained at frequencies >5 GHz by incorporating appropriate domain-controlled permalloy patterns with inductors.

Abstract

This brief relates to communication established through high-speed serial links. A serial communication channel can be formed by grouping multiple high-speed serial communication lanes to achieve greater serial bandwidth. Such channels require circuitry to eliminate relative skew across multiple lanes to ensure data integrity in the receiver. Channel bonding is a mechanism used to synchronize serial communication channels in larger data rate and bandwidth applications. This brief presents an approach to channel bonding that optimizes area, power, and initialization time and yields better performance. The ideas discussed here use a delay-based model and explore the possibility of performing channel bonding in a centralized way. The methodology is deployed in the Aurora Protocol Solution Suite, and a comparative analysis with another state-of-the-art approach is performed.

Abstract

We propose an alternate method to sense inertial rotation using semiconductor ring laser gyroscope (SRLG). We show that inertial rotation causes change in the magnitude of voltage across the terminals of semiconductor gain medium which can be measured externally to determine angular rotation velocity. The resonant oscillating frequency of the counter-traveling waves are not involved in the measurement which leads to elimination of lock-in in the gyro. The mathematical analysis and simulation results of the proposed method are also shown.

Abstract

We propose a novel method to eliminate the lock-in in a Semiconductor Fiber Ring Laser Gyroscope by orthogonally polarizing the counter-traveling waves in the ring cavity. Orthogonal polarization reduces the coupling between the waves which prevents them from locking.

Abstract

We find a single parameter family of genuinely entangled three qubit pure states, called maximally Bell inequality violating states, which exhibits maximum Bell inequality violation by the reduced bipartite system for a fixed amount of genuine tripartite correlation. This in turn implies that there holds a complementary relation between the Bell inequality violation by the reduced bipartite systems and the genuine tripartite correlation present in the tripartite pure states. Tangle, generalized geometric measure and discord monogamy score have been considered to quantify the genuine quantum correlation of the tripartite pure states. The complementarity suggests the Bell violation in the reduced two qubit system comes at the price of the total tripartite correlations present in the entire system.

Abstract

The basic motivation behind this work is to raise the question that whether post selection can be considered a valid physical transformation (on probability space) or not. We study the consequences of both answers set in a device (theory) independent framework, based only on observed statistics. We start with taking up post-selection as an assumption (if the answer is YES) and model the same using independent devices governed by Boolean functions. We establish analogy between the post selection functions and the general probabilistic games in a two party binary input-output scenario. As an observation, we categorize all possible post-selection functions based on the effect on a uniform input probability distribution. We find that post-selection can transform simple no signaling probability distributions to signaling. Similarly, solving NP (nondeterministic polynomial time) complete problems is easy independent of classical or quantum computation (in particular we prove that Post RP (Randomized Polynomial Time) = NP). Finally, we demonstrate an instance of the violation of the pigeon hole principle independent of underlying theory. As result of our theory independent modeling we conclude that post-selection as an assumption adds power to the underlying theory. In particular, quantum mechanics benefits more with the post-selection assumption, only because it admits a more general set of allowed probabilities as compared to the local hidden variable model. Without the assumption (if the answer is NO) we associate a device independent efficiency factor to quantify the cost of post selection. Our study shows that in the real world post-selection is not efficient enough to be of any advantage. But from an adversarial perspective it is still of significance. As an application, we obtain robust bounds on faking the bell violation (correlation in general) in terms of minimum efficiency required using post selection. Here in this work we argue that post-selection as an assumption is not physical. In the real world post-selection is simply dropping trials based on a pre-decided rule. It makes physical reality appear surprising. However, we suggest the use of post-selection with an device independent trial efficiency to avoid anomalous effects.

Abstract

We quantify the amount of correlations generated between two different output modes in the process of imperfect cloning and deletion processes. We use three different measures of quantum correlations and investigate their role in determining the fidelity of the cloning and the deletion. We obtain a bound on the total correlation generated in the successive processes of cloning and deleting operations. This bound displays a new kind of complementary relationship between the quantum correlations required in generating a copy of a quantum state and the amount of correlations required in bringing it back to the original state by deleting and vice versa. Our result shows that the better we clone (delete) a state, the more difficult it will be to bring the state back to its original form by the process of deleting (cloning).