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Model-driven scheduling for distributed stream processing systems
No full textDistributed Stream Processing Systems (DSPS) are ``Fast Data'' platforms that allow streaming applications to be composed and executed with low latency on commodity clusters and Clouds. Such applications are composed as a Directed Acyclic Graph (DAG) of tasks, with data parallel execution using concurrent task threads on distributed resource slots. Scheduling such DAGs for DSPS has two parts-allocation of threads and resources for a DAG, and mapping threads to resources. Existing schedulers often address just one of these, make the assumption that performance linearly scales, or use ad hoc empirical tuning at runtime. Instead, we propose model-driven techniques for both mapping and allocation that rely on low-overhead a priori performance modeling of tasks. Our scheduling algorithms are able to offer predictable and low resource needs that is suitable for elastic pay-as-you-go Cloud resources, support a high input rate through high VM utilization, and can be combined with other mapping approaches as well. These are validated for micro and application benchmarks, and compared with contemporary schedulers, for the Apache Storm DSPS. (C) 2018 Elsevier Inc. All rights reserved
Generalization and demonstration of an entanglement-based Deutsch-Jozsa-like algorithm using a 5-qubit quantum computer
No full textThis paper demonstrates the use of entanglement resources in quantum speedup by presenting an algorithm which is the generalization of an algorithm proposed by Goswami and Panigrahi (Essentiality of entanglement in a quantum algorithm, 2017.arXiv:1706.09489). We generalize the algorithm and show that it provides deterministic solutions having an advantage over classical algorithm. The algorithm answers the question of whether a given function is constant or balanced and whether two functions are equal or unequal. Finally, we experimentally verify the algorithm by using IBM's five-qubit quantum computer with a high fidelity
Strong sea forcing and warmer winter during solar minima similar to 2765 yr BP recorded in the growth bands of Crassostrea sp. from the confluence of river Ganges, Eastern India
No full textLong term variation of solar activity plays a key role in controlling climatic oscillations during glacial-interglacial cycles. The records of such climatic shifts can be retrieved from sedimentary archives in overbank deposits found in the estuary regions of major rivers in the tropics which are fed by glaciers. In this study we have shown the effect of solar variability on regional climate by altering the river discharge and incursion of warm water pool into the region adjoining Bay of Bengal during seasonal dry period. The incremental growth bands present in the modern day Meretrix sp and Late Holocene Crassostrea sp. were examined for reconstruction of temperature and water composition at the head bay region of the river Ganges. The conventional C-14 techniques on fossil oyster yielded age of 2765 +/- 130 yr B.P., which coincides with a solar minima. Analysis of clumped isotope thermometry on the growth bands provided temperature estimates for the growth of shells. The temperature estimates for the modern shell, suggesting range of values showed a range between 13 degrees and 42 degrees C, close to the observed temperatures recorded in the climatological data while the fossil shell had a range of values between 22 degrees and 38 degrees C. The delta O-18 measured in the aragonite together with the estimated temperature were used to deduce the water composition during growth at equilibrium condition. The water delta O-18 varied between -4.8% and 1.2% for the modern sample, close to the observed values of water measured near this locality, while the range in water composition inferred for the paleo samples was from -2.37% to 0.82%, suggesting a stronger influence of sea water throughout the year. The results are consistent with the argument of infiltration of water from neighbouring warm water pool into the estuary. A similar approach can be extended to evaluate the effects of climate variability due to differential action of river discharge into the sea at seasonal time scales based on available mollusc shells in the sedimentary successions from the region. (C) 2017 Elsevier Ltd and INQUA. All rights reserved
Development of microstructure and texture during single and multiple pass friction stir processing of a strain hardenable aluminium alloy
No full textIn the present study, microstructure and texture development during single and multiple pass friction stir processing (FSP) of a strain hardenable wrought Al-Mg alloy (AA5086) was investigated. Subtle differences were observed while comparing with heat treatable alloys in the nucleation mechanism of the recrystallized microstructure observed in the nugget zone. Strain induced boundary migration was the dominant mechanism of microstructure evolution in the alloy, which influenced the crystallographic texture development by weakening it. Micro-texture measurements reveal variations in the crystallographic texture along the thickness of the sample. Recrystallization texture components were observed in the nugget zone indicative of a pronounced static recrystallization in the alloy as compared to the heat treatable alloys. Bulk texture measurements within the nugget zone of the optimally processed sample reveal a relatively dominant C component of shear texture. Average grain size in the nugget zone remained the same and the bulk crystallographic texture components were retained during multiple-pass FSP. The lower strain energies involved and the enhanced recovery processes due to the high temperature materials processing of the alloy during FSP resulted in a stable microstructure and texture. In summary, FSP could be promoted as a competent and suitable secondary processing technique for the bulk production of ultra-fine-grained materials in strain hardenable aluminium alloys
Protein stabilization by tuning the steric restraint at the reverse turn
No full textReverse turns are solvent-exposed motifs in proteins that are crucial in nucleating -sheets and drive the protein folding. The solvent-exposed nature makes reverse turns more amenable to chemical modifications than -helices or -sheets towards modulating the stability of re-engineered proteins. Here, we utilize van der Waals repulsive forces in tuning the steric restraint at the reverse turn. The steric restraint induced upon N-methylation of the i+1-i+2 amide bond at the reverse turn results in well-folded and stable -sheets in aqueous solution at room temperature. The developed superactive turn inducing motif is tolerant to a wide variety of functional groups present on coded amino acids making the designed turn fully compatible with bioactive loops in proteins. We demonstrate that the steric restraint and the functional groups at the reverse turn act in synergy to modulate the folding of re-engineered -sheets. Introduction of the turn motifs onto a three-stranded -sheet protein, Pin 1 WW domain, resulted in various analogs showing a cooperative two-state transition with thermal stability (T-M) ranging from 62 degrees C to 82 degrees C. Despite modulating the stability of Pin 1 variants by approximate to 2.8 kcal mol(-1) (G(f)), the native fold in all the protein variants was found to be unperturbed. This structural stability is brought about by conformational preorganization at the engineered reverse turn that results in strong intramolecular hydrogen bonds along the three dimensional structure of the protein. Thus, this simple loop engineering strategy via two amino acid substitution provides us a toolkit to modulate the stability of -sheet containing peptides and proteins in aqueous solution that will greatly expand the scope of de novo protein and foldamer design
Woody shrubs increase soil microbial functions and multifunctionality in a tropical semi-arid grazing ecosystem
No full textWoody encroachment is of global concern in arid and semiarid regions around the world. Due to reduction in grass (forage), woody encroachment is viewed as ecosystem disservice and degradation, even though this may not reduce ecosystem functions. Often, management perceptions of degradation remain inadequately informed by knowledge of ecosystem processes. We compared 11 biotic variables related to soil and microbial functions under shrubs against paired-adjacent grassland:-carbon, nitrogen, C:N ratio, organic matter, plant-available N, N-mineralization rate, microbial biomass C and N, basal respiration, and metabolic-quotient. We summarized these as a multifunction-index. We also measured five soil physico-chemical covariates:-pH, conductivity, bulk density, texture and water holding capacity. These 11 biotic variables were 15-48% higher under shrubs than under grass; multifunction-index was also higher (by 366%). After accounting for spatial autocorrelation and background differences in physico-chemical covariates (redundancy analysis), altered ecosystem functions were attributable to shrubs. Overall, shrubs can enhance ecosystem functions, and maintain important ecological processes through concomitant changes in soil physico-chemical properties. While shrubs should not be equated to ecological degradation, they present a challenging triage of ecosystem service, disservice, and function for grasslands. Management strategies could benefit from targeting patterns of nutrient redistribution under shrubs
Torque Ripple Minimization in Neutral-Point-Clamped Three-Level Inverter Fed Induction Motor Drives Operated at Low-Switching-Frequency
No full textNeutral-point-clamped (NPC) multilevel inverter fed high power drives operating at low switching frequency are prone to low-order torque pulsations. For a case of N switching angles per quarter, apart from maintaining the fundamental component, (N - 1) voltage harmonics can be eliminated. Consequently, N-1/2 or lower number of torque harmonics could be eliminated. This paper proposes an optimal pulse-width modulation (PWM), which minimizes the combined root mean square (RMS) value (tau(RMS)) of torque harmonics of order lower than 6N at anymodulation index (M) for an induction motor drive fed from an NPC three-level inverter. This paper considers cases of two, three, and four switching angles per quarter cycle of the pole voltage. Compared with synchronized sine-triangle PWM and selective harmonic elimination (SHE) PWM, the proposed PWM reduces the first (N -1) torque harmonics (i.e., tau(6), tau(12),. . ., tau(6(N-1))) over a wide speed range. Simulation and experimental results are presented on a 3.7-kW open-loop constant volts-per-Hertz induction motor drive
Clockwork for neutrino masses and lepton flavor violation
No full textWe investigate the generation of small neutrino masses in a clockwork framework which includes Dirac mass terms as well as Majorana mass terms for the new fermions. We derive analytic formulas for the masses of the new particles and for their Yukawa couplings to the lepton doublets, in the scenario where the clockwork parameters are universal. When the universal Majorana mass vanishes, the zero mode of the clockwork sector forms a Dirac pair with the active neutrino, with a mass which is in agreement with oscillations experiments for a sufficiently large number of clockwork gears. On the other hand, when it does not vanish, neutrino masses are generated via the seesaw mechanism. In this case, and due to the fact that the effective Yukawa couplings of the higher modes can be sizable, neutrino masses can only be suppressed by postulating a large Majorana mass scale. Finally, we discuss the constraints on the mass scale of the clockwork fermions from the non-observation of the rare leptonic decay mu -> e gamma. (C) 2018 The Authors. Published by Elsevier B.V
Direct Observation of Intermediate State(s) in the Mechanistic Investigation of Domain Specific Protein-Surfactant Interaction
No full textIntroduction: Interaction of surfactants with proteins can decipher important information regarding the stability and behavior of proteins. For multi-domain proteins, these interactions vary domain wise and these details are crucial in understanding the contribution of different domains of the protein in its overall activity. Objective: The objective of the present work is to study the interaction of surfactants with domain III of Human Serum Albumin (HSA) and to compare the same with the global interaction. Methods: Interaction of the anionic Sodium Dodecyl Sulphate (SDS) and the Cationic Cetyltrimethylammonium Bromide (CTAB) surfactants with domain III of Human Serum Albumin (HSA) has been studied using 8-Anilino-1-Naphthalene-Sulphonate (ANS) as a fluorescent marker. Circular Dichroism (CD) spectroscopy has been used to study the protein-surfactant interaction for the overall protein. Results: SDS is found to interact sequentially with domain III of HSA having two detectable intermediate states in the binding process. In case of CTAB, we have observed only one intermediate state for its interaction with domain III. Although Quantum yield measurement can reflect the presence of such intermediate state, the overall conformational change of the HSA on addition of surfactants, studied by Circular Dichroism (CD) spectroscopy, and the ANS-Trp distance measurement by FRET could not resolve the presence of such intermediate states. The esterase activity of HSA in presence of different amount of surfactants is also in accordance with our above observation. Conclusion: The interaction of both the surfactants with HSA is found to be sequential in nature. The most important conclusion revealed from our study is that the nature of protein-surfactant interaction is not same throughout the entire protein. Our study reveals that different parts of the multi-domain HSA have different affinity to the surfactant molecules