Hot Little String Correlators: A View From Supergravity

We study the propagation of a massless minimally coupled scalar in the near horizon geometry of non-extremal NS5-branes. Using the holographic principle for dilatonic backgrounds we compute the two-point function of an operator in Little String Theory at the Hagedorn temperature. We then comment on relations with correlation functions in two dimensional string theory.Comment: 15 pages, latex, v2 references adde

Formulation, Optimization and Evaluation of Self Emulsifying Immediate Release Tablet of Nebivolol HCl using 32 Factorial Design

Nebivolol Hydrochloride (NEB) is a lipophilic molecule with low solubility in GI fluid, and high metabolism which leads to its low oral bioavailability 12%. The aim of the present investigation was to develop immediate release self emulsifying tablet (IR-SET) as solid SMEDDS to enhance the solubility and permeability of the drug. Solubility study, pseudo-ternary phase diagrams and 32 factorial design were used to select the components of the system and optimize the composition of liquid SMEDDS. Optimal L-SMEDDS contains Kollisolv GTA, Tween 80 and Propylene glycol as oil, surfactant and co-surfactant, respectively in the ratio of 20:26.66:53.34 % w/w, formulates L-SMEDDS with droplet size (55.98 nm), PDI (0.37), emulsification time (16±1.52 sec) and drug content (97.43±0.30 %).  The liquid SMEDDS were adsorbed onto Neusilin US2 by adsorbtion technique to form S-SMEDDS. DSC and SEM studies suggested that NEB in the S-SMEDDS may be present in the molecular dispersed state and was sufficiently adsorbed onto solid carrier, respectively. S-SMEDDS was compressed into IR-SET by direct compression method and composition of IR-SET was optimized using 32 factorial design. Optimal IR-SET showed disintegration time (92 + 0.57 sec), droplet size (68.57 nm), PDI (0.34) and drug content (96.33±0.15 %). In vitro dissolution studies and ex vivo diffusion studies in rat stomach suggested that SMEDDS played an important role in solubility and permeability enhancing effect. Accelerated stability studies indicated that formulation were stable. Our results illustrated the increase in solubility and permeability of drug from IR-SET

Performance Comparison of Symmetric and Offset Reflector Antennas Adaptively Illuminated by Novel Triple Mode Feedhorn

Parabolic symmetric and offset reflector antennas adaptively illuminated using a novel triple-mode feedhorn (TE11+TM01+TE21) with different mode combinations and impedance and radiation performances are presented. The combination of the radiating modes in a feedhorn with proper amplitude and fixed phase values helps in electronically pointing the main beam of the radiating patterns such as that obtained in a beam-steering antenna with limited beam-scan range. This type of radiation performance virtually creates a displaced phase center location for the feedhorn, which, consequently, adaptively illuminates the reflector antenna surface. Impedance-matching bandwidths are preserved for both reflector antennas similar to the case of feedhorn alone. The copolarization gain and peak cross-polarization levels are far better with the offset reflector antenna than the symmetric reflector antenna. Such reflector antennas find applications in ground moving target indicator (GMTI) and space based radars. The investigation results are solely computed using FEKO full-wave analysis tool

Cognitive Spam Recognition Using Hadoop and Multicast-Update

In today's world of exponentially growing technology, spam is a very common issue faced by users on the internet. Spam not only hinders the performance of a network, but it also wastes space and time, and causes general irritation and presents a multitude of dangers - of viruses, malware, spyware and consequent system failure, identity theft, and other cyber criminal activity. In this context, cognition provides us with a method to help improve the performance of the distributed system. It enables the system to learn what it is supposed to do for different input types as different classifications are made over time and this learning helps it increase its accuracy as time passes. Each system on its own can only do so much learning, because of the limited sample set of inputs that it gets to process. However, in a network, we can make sure that every system knows the different kinds of inputs available and learns what it is supposed to do with a better success rate. Thus, distribution and combination of this cognition across different components of the network leads to an overall improvement in the performance of the system. In this paper, we describe a method to make machines cognitively label spam using Machine Learning and the Naive Bayesian approach. We also present two possible methods of implementation - using a MapReduce Framework (hadoop), and also using messages coupled with a multicast-send based network - with their own subtypes, and the pros and cons of each. We finally present a comparative analysis of the two main methods and provide a basic idea about the usefulness of the two in various different scenarios

5-Exo-dig, 5-exo-trig cascade radical cyclisation on sugar-furanose templates: entry to angularly fused oxa-and dioxa-triquinane skeletons

Serial radical cyclisation on sugar-furanose templates to create angularly fused oxa- and dioxa-triquinane skeletons has been described, the salient feature of this approach being to incipiently generate a tertiary radical from cyclopropylmethyl bromide with simultaneous release of allyl group and to subsequently incorporate it in the triquinane system

Extremal vacuum black holes in higher dimensions

We consider extremal black hole solutions to the vacuum Einstein equations in dimensions greater than five. We prove that the near-horizon geometry of any such black hole must possess an SO(2,1) symmetry in a special case where one has an enhanced rotational symmetry group. We construct examples of vacuum near-horizon geometries using the extremal Myers-Perry black holes and boosted Myers-Perry strings. The latter lead to near-horizon geometries of black ring topology, which in odd spacetime dimensions have the correct number rotational symmetries to describe an asymptotically flat black object. We argue that a subset of these correspond to the near-horizon limit of asymptotically flat extremal black rings. Using this identification we provide a conjecture for the exact ``phase diagram'' of extremal vacuum black rings with a connected horizon in odd spacetime dimensions greater than five.Comment: 53 pages, latex, 19 eps figures. v2: added refs + one eps figure. v3: published versio

Model checking time-constrained scenario-based specifications

We consider the problem of model checking message-passing systems with real-time requirements. As behavioural specifications, we use message sequence charts (MSCs) annotated with timing constraints. Our system model is a network of communicating finite state machines with local clocks, whose global behaviour can be regarded as a timed automaton. Our goal is to verify that all timed behaviours exhibited by the system conform to the timing constraints imposed by the specification. In general, this corresponds to checking inclusion for timed languages, which is an undecidable problem even for timed regular languages. However, we show that we can translate regular collections of time-constrained MSCs into a special class of event-clock automata that can be determinized and complemented, thus permitting an algorithmic solution to the model checking problem

O Mediterrâneo enquanto metáfora da mestiçagem: Novas leituras sobre o modelo europeu na América Latina dos anos 1920

After the First World War, we can observe in the Latin American society a strong transformation in the perception of the Europe as a civilization model. New movements in art and literature start to rethink the National Identities in Latin America and in the whole subcontinent born a criticism against the importation of European civility concepts. This process can be deeply analyzed in Mistral’s writings that shows us the continental transformation through the Mediterranean metaphor: between a Latin space and a space of miscegenation. In Mistral’s narratives, we can notice two kinds of analytical movements between North and South relations: when the writer talks about the European contrasts, she talks also about those of the American continent. In this context, the Old World, or its Southern part, shares its Historical experience with the New World to justify the positive perception of the New Latin American men: Multiethnic

Safety verification of asynchronous pushdown systems with shaped stacks

In this paper, we study the program-point reachability problem of concurrent pushdown systems that communicate via unbounded and unordered message buffers. Our goal is to relax the common restriction that messages can only be retrieved by a pushdown process when its stack is empty. We use the notion of partially commutative context-free grammars to describe a new class of asynchronously communicating pushdown systems with a mild shape constraint on the stacks for which the program-point coverability problem remains decidable. Stacks that fit the shape constraint may reach arbitrary heights; further a process may execute any communication action (be it process creation, message send or retrieval) whether or not its stack is empty. This class extends previous computational models studied in the context of asynchronous programs, and enables the safety verification of a large class of message passing programs