Evolution of Structure Functions And Their Moments In Chiral Field Theory

Evolution of structure functions and their moments at low and moderate $Q^2$ is studied in the chiral field theory. Evolution equations based on perturbation expansion in the coupling constant of the effective theory are derived and solved for the moments. The kernels of evolution arising from different processes have been calculated with contributions from direct and cross channels, the interference terms being non-negligible in the kinematic regions under consideration. This is shown to lead to flavor-dependence of the kernels which manifests in observable effects. The invalidity of the probabilistic approach to the evolution process is also pointed out.Comment: 18 pages, LaTex, 5 figure

HIF-INDEPENDENT RESPONSES IN HYPOXIA

The adaptive response to hypoxia is accompanied by widespread transcriptional changes that allow for prolonged survival in low oxygen. Many of these changes are directly regulated by the conserved hypoxia-inducible factor-1 (HIF-1) complex; however, even in its absence, many oxygen-sensitive transcripts in Caenorhabditis elegans are appropriately regulated in hypoxia. To identify mediators of these non-HIF-dependent responses, I established a hif-1 mutant reporter line that expresses GFP in hypoxia or when worms are treated with the hypoxia mimetic cobalt chloride (cobalt chloride). The reporter is selective and HIF-independent, in that it remains insensitive to a number of cellular stresses, but is unaffected by mutation of the prolyl hydroxylase egl-9, suggesting that the regulators of this response pathway are different from those controlling the HIF pathway. I used the HIF-independent reporter to screen a transcription factor RNAi library and identified genes that are required for hypoxia sensitive and cobalt chloride-induced GFP expression. Three mediators of the HIF-independent response zinc finger protein BLMP-1, chromatin remodeling factor LIN-40, and T-box transcription factor TBX-38 were isolated as mediators of the HIF-independent response. First, we show that mutation of blmp-1 renders animals sensitive to hypoxic exposure and that blmp-1 it is required for appropriate hypoxic-induced expression of HIF-independent transcripts. Further, we demonstrate that BLMP-1 is necessary for an increase of hypoxia-dependent histone acetylation within the promoter of a non-HIF-dependent hypoxia response gene. Additionally, we explore BLMP-1’s role in two hypoxia-regulated physiological processes namely unfolded protein response and collagen formation. We also briefly investigate the role of LIN-40 in the hypoxia response

A Computational Model to Estimate the Thickness of the Waterfilm Due to Rain on the Upper Surface of an Airfoil

Based on a two-phase boundary layer approach, a computational model is proposed to estimate the thickness of the waterfilm due to rain on the upper surface of an airfoil. The coupling between the air boundary layer and the water film is established by the conservation of mass and momentum at the interface. By a simple coordinate transformation, the interface is conformed to the finite difference grid system. Trajectory analysis of a raindrop of 1 mm diameter shows that the impingement of drops is high near the leading edge of the airfoil and decreases downstream. The finite difference equations of air/waterfilm are based on a Crank Nicholson scheme. The solution of finite difference equations at the initial station indicates a film thickness of 0.01 mm. Marching downstream along the surface of the airfoil gives raise to stability problems in the finite difference equations

Scalable Systems for Large Scale Dynamic Connected Data Processing

As the proliferation of sensors rapidly make the Internet-of-Things (IoT) a reality, the devices and sensors in this ecosystem—such as smartphones, video cameras, home automation systems, and autonomous vehicles—constantly map out the real-world producing unprecedented amounts of dynamic, connected data that captures complex and diverse relations. Unfortunately, existing big data processing and machine learning frameworks are ill-suited for analyzing such dynamic connected data and face several challenges when employed for this purpose.This dissertation focuses on the design and implementation of scalable systems for dynamic connected data processing. We discuss simple abstractions that make it easy to operate on such data, efficient data structures for state management, and computation models that reduce redundant work. We also describe how bridging theory and practice with algorithms and techniques that leverage approximation and streaming theory can significantly speed up connected data computations. The systems described in this dissertation achieve more than an order of magnitude improvement over the state-of-the-art

Measurement of the threshold sensitivity of honeybees to weak, extremely low-frequency magnetic fields

Experiments reported previously demonstrate that free-flying honeybees are able to detect static intensity fluctuations as weak as 26 nT against the background, earth-strength magnetic field. We report here an extension of this work to weak, alternating fields at frequencies of 10 and 60 Hz. Our results indicate that the sensitivity of the honeybee magnetoreception system decreases rapidly with increasing frequency. At 60 Hz, alternating field strengths above 100 µT are required to elicit discrimination. These results are consistent with biophysical predictions of a magnetite-based magnetoreceptor

Phase ambiguity of the threshold amplitude in pp -> pp\pi^0

Measurements of spin observables in pp -> {\vec p}{\vec p}\pi^0 are suggested to remove the phase ambiguity of the threshold amplitude. The suggested measurements complement the IUCF data on {\vec p}{\vec p} -> pp\pi^0 to completely determine all the twelve partial wave amplitudes, taken into consideration by Mayer et.al. [15] and Deepak, Haidenbauer and Hanhart [20].Comment: 4 pages, 1 table