Cosmological horizon entropy and generalised second law for flat Friedmann Universe

We discuss the generalized second law (GSL) and the constraints imposed by it for two types of Friedmann universes. The first one is the Friedmann universe with radiation and a positive cosmological constant, and the second one consists of non-relativistic matter and a positive cosmological constant. The time evolution of the event horizon entropy and the entropy of the contents within the horizon are analyses in an analytical way by obtaining the Hubble parameter. It is shown that the GSL constraint the temperature of both the radiation and matter of the Friedmann universe. It is also shown that, even though the net entropy of the radiation (or matter) is decreasing at sufficiently large times as the universe expand, it exhibit an increase during the early times when universe is decelerating. That is the entropy of the radiation within the comoving volume is decreasing only when the universe has got an event horizon.Comment: 15 pages, 9 figure

An Automata-Theoretic Approach to the Verification of Distributed Algorithms

We introduce an automata-theoretic method for the verification of distributed algorithms running on ring networks. In a distributed algorithm, an arbitrary number of processes cooperate to achieve a common goal (e.g., elect a leader). Processes have unique identifiers (pids) from an infinite, totally ordered domain. An algorithm proceeds in synchronous rounds, each round allowing a process to perform a bounded sequence of actions such as send or receive a pid, store it in some register, and compare register contents wrt. the associated total order. An algorithm is supposed to be correct independently of the number of processes. To specify correctness properties, we introduce a logic that can reason about processes and pids. Referring to leader election, it may say that, at the end of an execution, each process stores the maximum pid in some dedicated register. Since the verification of distributed algorithms is undecidable, we propose an underapproximation technique, which bounds the number of rounds. This is an appealing approach, as the number of rounds needed by a distributed algorithm to conclude is often exponentially smaller than the number of processes. We provide an automata-theoretic solution, reducing model checking to emptiness for alternating two-way automata on words. Overall, we show that round-bounded verification of distributed algorithms over rings is PSPACE-complete.Comment: 26 pages, 6 figure

Power System Stability Studies Using Matlab

The stability of an interconnected power system is its ability to return to normal or stable operation after having been subjected to some form of disturbance. With interconnected systems continually growing in size and extending over vast geographical regions, it is becoming increasingly more difficult to maintain synchronism between various parts of the power system. • In our project we have studied the various types of stability- steady state stability, transient state stability and the swing equation and its solution using numerical methods using MATLAB and Simulink . • We have presented the solution of swing equation for transient stability analysis using three different methods – Point-by-Point method, Modified Euler method and Runge-Kutta method. • Modern power systems have many interconnected generating stations, each with several generators and many loads. So our study is not limited to one-machine system but we have also studied multi-machine stability. • We study the small-signal performance of a machine connected to a large system through transmission lines. We gradually increase the model detail by accounting for the effects of the dynamics of the field circuit. We have analysed the small-signal performance using eigen value analysis. • Further a more detailed transient stability analysis is done whereby the classical model is slightly improved upon by taking into account the effect of damping towards transient stability response. Characteristics of the various components of a power system during normal operating conditions and during disturbances have been examined, and effects on the overall system performance are analyzed

Arabidopsis mutants reveal multiple singlet oxygen signaling pathways involved in stress response and development

Shortly after the release of singlet oxygen (1O2) in chloroplasts drastic changes in nuclear gene expression occur in the conditional flu mutant of Arabidopsis that reveal a rapid transfer of signals from the plastid to the nucleus. Factors involved in this retrograde signaling were identified by mutagenizing a transgenic flu line expressing a 1O2-responsive reporter gene. The reporter gene consisted of the luciferase open reading frame and the promoter of an AAA-ATPase gene (At3g28580) that was selectively activated by 1O2 but not by superoxide or hydrogen peroxide. A total of eight second-site mutants were identified that either constitutively activate the reporter gene and the endogenous AAA-ATPase irrespectively of whether 1O2 was generated or not (constitutive activators of AAA-ATPase, caa) or abrogated the 1O2-dependent up-regulation of these genes as seen in the transgenic parental flu line (non-activators of AAA-ATPase, naa). The characterization of the mutants strongly suggests that 1O2-signaling does not operate as an isolated linear pathway but rather forms an integral part of a signaling network that is modified by other signaling routes and impacts not only stress responses of plants but also their developmen

Dual Signal Optical Bistability in a Semiconductor Optical Amplifier

Future all-optical signal processing applications may require the use of multiple optical signals passing through a single, optically bistable device. My thesis investigates an improved model for modeling two optical signals passing through an optically bistable Fabry-Perot semiconductor optical amplifier (FP-SOA). The optical power and phase of these signals are both modeled, as well as the optical gain of the FP-SOA. My improved model is based on an improved model used to study optical bistability of just a single optical signal, in which the internal power is related to the output power with an expression accounting for the Fabry-Perot structure. Work has been performed to put all models into a consistent notation. The resulting, improved model for dual-signal operation indicates lower critical powers to trigger bistable action

A Study on Social Performance of Microfinance Institutes: A Consumer Perspective

The objective of the paper is to conduct a comparative study on the social performance of MFIs in rural and urban areas in various districts of Kerala and analyze the overall impact of micro financial services on the lives of respondents in these areas. The study is undertaken in rural and urban areas of four districts in Kerala using primary data. A total of 110 samples were collected from the districts of Alappuzha, Kollam, Pathanamthitta and Ernakulam. The analysis shows that the borrowers have seen an improvement in their standard of living because of the financial assistance provided by microfinance institutions. The comparison of the rural and urban areas shows that there are considerable differences as people in urban areas are more beneficial from the service provided by MFIs and the main reason behind this is their income status. The people in urban areas have high financial backup as compared to rural areas, so they are more benefitted from the loan facilities availed from MFIs to start their own ventures

CORRELATION BETWEEN MATERNAL COMPLICATIONS AND THE MENTAL HEALTH OF THE OFFSPRING

INTRODUCTION Children and young adults with mental disorders are twice as more likely to have experienced a complication of birth or pregnancy. Using an informatics approach, this study examines the impact of complications during birth and pregnancy on the mental health of the youth in the local pediatric population (Calgary Research Ethics Board ID: 21695). METHODS A data set containing physician visit for approximately 240,000 unique individuals from 1994-2009 was employed to examine the type of mental disorder associated with complications of birth and pregnancy (as a major class of ICD disorders). Additionally, a systematic literature review and meta-analysis of pediatric mental disorder associated with complications of birth and pregnancy was undertaken. RESULTS Mothers who experienced gestational infection, disease or exposure to drugs had a 3.7-fold increased risk of giving birth to children with mental disorders. Perinatal risk factors and obstetric complications caused a 1.5-fold increased risk. Emotional violence during pregnancy was seen to correlate with premature birth. Forest plot revealed that gestational diabetes and gestational influenza were the leading risk factors. In the local pediatric population from 1994 to 2009, the prevalence of offspring born with mental disorders whose mothers experienced complications during pregnancy and childbirth increased from 18 individuals/1000 to 28 individuals/1000 - an increase by 1.4. DISCUSSION One serious question that must be looked into is whether it is the influenza itself that impacts the child’s mental health, or the antibiotic medication that most mothers are prescribed as a remedy for influenza that has the negative impact on the child’s mental health. CONCLUSION On average, maternal gestational infection, disease and drug exposure, perinatal risk factors and obstetric complications, and maternal emotional violence leads to a 2 fold increased risk of offspring being born with mental disorders. In the local population, the prevalence of mental disorders consequent to pregnancy and childbirth complications has increased by a factor of 1.4 during the 1994-2009 period in the U19 category