Cloud Process Execution Engine - Evaluation of the Core Concepts

In this technical report we describe describe the Domain Specific Language (DSL) of the Workflow Execution Execution (WEE). Instead of interpreting an XML based workflow description language like BPEL, the WEE uses a minimized but expressive set of statements that runs directly on to of a virtual machine that supports the Ruby language.Frameworks/Virtual Machines supporting supporting this language include Java, .NET and there exists also a standalone Virtual Machine. Using a DSL gives us the advantage of maintaining a very compact code base of under 400 lines of code, as the host programming language implements all the concepts like parallelism, threads, checking for syntactic correctness. The implementation just hooks into existing statements to keep track of the workflow and deliver information about current existing context variables and state to the environment that embeds WEE

The characterization of humic substances in seawater

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September, 1975Humic substances were isolated in gram quantities from seawater by a newly developed procedure of adsorption on a crosslinked polystyrene-divinylbenzene resin. The chemical and physical characteristics of both humic acid and fulvic acid fractions were studied. The elemental composition, the acidimetric titration characteristics, the l3C: l2C ratios, and the ultraviolet-visible, fluorescence, and infrared spectra were determined. Molecular weight distributions of coastal and Sargasso Sea fulvic acids were measured by gel permeation chromatography. Structural features were further investigated by both proton and carbon-13 nuclear magnetic resonance spectroscopy. In addition, the fulvic acids and their derivatives were analyzed by low and high resolution mass spectrometry and combined gas chromatography-mass spectrometry (GC-MS). Amino acids and organic solvent soluble products in acid hydrolyzates were investigated. An array of biogenic hydrocarbons produced from fulvic acid by a new reduction scheme were characterized by GC-MS. The structural features of seawater humic substances are complex. They are highly aliphatic, polyfunctional materials containing both polar and nonpolar moieties. Hydrolyzable amino acids constitute a low percentage of the nitrogen. Fatty acids and other lipids are important structural components. Seawater humic substances have significant structural differences from those of terrestrial origin; this seems to result mainly from the relatively low input of lignin to the marine environment and the differences between the physical environment of the soil and the sea. A mechanism is proposed for the formation of seawater humic substances from amino acids, sugars and lipids. The effects and fate of humic substances in the sea are discussed.This researcn has been graciously supported by the National Science Foundation (Doctoral Dissertation Grant GA-36631) and by Graduate Fellowships provided by the Arthur Vining Davis Foundations and the Woods Hole Oceanographic Institution

On the economic determinants of optimal stock-bond portfolios: international evidence

Using a modified DCC-MIDAS specification that allows the long-term correlation component to be a function of multiple explanatory variables, we show that the stock-bond correlation in the US, the UK, Germany, France, and Italy is mainly driven by inflation and interest rate expectations as well as a flight-to-safety during times of stress in financial markets. Based on the new DCC-MIDAS model, we construct stock-bond hedge portfolios and show that these portfolios outperform various benchmark portfolios in terms of portfolio risk. While optimal daily weights minimize portfolio risk, we find that portfolio turnover and trading costs can be substantially reduced when switching to optimal monthly weights

Directed evolution of Vibrio fischeri LuxR for improved response to butanoyl-homoserine lactone

LuxR is the 3-oxohexanoyl-homoserine lactone (3OC6HSL) dependent transcriptional activator of the prototypical acyl-homoserine lactone (AHL) quorum sensing system of Vibrio fischeri. Wild-type LuxR exhibits no response to butanoyl-HSL (C4HSL) in quantitative bioassays at concentrations of up to 1 µM; a previously described LuxR variant (LuxR-G2E) exhibits a broadened response to diverse AHLs, including pentanoyl-HSL (C5HSL), but not to C4HSL. Here, two rounds of directed evolution of LuxR-G2E generated variants of LuxR that responded to C4HSL at concentrations as low as 10 nM. One variant, LuxR-G4E, had only one change, I45F, relative to the parent LuxR-G2E, which itself differs from wild-type at three residues. Dissection of the four mutations within LuxR-G4E demonstrated that at least three of these changes were simultaneously required to achieve any measurable C4HSL response. The four changes improved both sensitivity and specificity towards C4HSL relative to any of the other 14 possible combinations of those residues. These data confirm that LuxR is evolutionarily pliable and suggest that LuxR is not intrinsically asymmetric in its response to quorum sensing signals with different acyl-side chain lengths

A comparison of the normal and regenerated retinotectal pathways of goldfish

This is a light and electron microscopic study of the retinotectal pathway: intact and after regeneration of the optic nerve. The spatiotemporal pattern of axonal outgrowth and termination was studied with the methods of proline autoradiography, horseradish peroxidase (HRP) labeling, and fiber degeneration. The spatial order of optic fibers in the normal and regenerated pathways was assessed by labeling small groups intraretinally with HRP and then tracing them to the tectum. The labeled fibers occupied a greater fraction of the cross section of the regenerated than the normal optic tract. At the brachial bifurcation, roughly 20% of the regenerated fibers chose the incorrect brachium vs. less than 1% of the normals. In tectum, the regenerated optic fibers reestablished fascicles in stratum opticum , but they were less orderly than in the normals. The retinal origins of the fibers in the fascicles were established by labeling individual fascicles with HRP and then, following retrograde transport, finding labeled ganglion cells in whole-mounted retinas. Labeled cells were more widely scattered over the previously axotomized retinas than over the normal ones. A similar result was obtained when HRP was applied in the tectal synaptic layer. All of these results indicate that the pathway of the regenerated optic fibers is less well ordered than the intact pathway. Both autoradiography and HRP showed that the regenerating optic fibers invaded the tectum from the rostral end, and advanced from rostral to caudal and from peripheral to central tectum, along a front roughly perpendicular to the tectal fascicles. Synapses of retinal origin were noted electron microscopically in the tectum at the same sites where autoradiography indicated that the fibers had arrived. No retinal terminals were seen where grain densities were at background levels. Fiber ingrowth and synaptogenesis apparently occurred simultaneously. The synapses were initially smaller and sparser than in normals, but were in the normal tectal strata and contacted the same classes of post synaptic elements as in normals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50021/1/902230106_ftp.pd

The Effects of Parathyroid Hormone Applied at Different Regimes on the Trochanteric Region of the Femur in Ovariectomized Rat Model of Osteoporosis

This study aims to investigate the effects of two application frequencies of parathyroid hormone on the trochanteric region of rat femur. Forty-three-month-old female Sprague-Dawley rats were divided into 4 groups (n = 10/group). Three groups were ovariectomized, and 8 weeks later they were administered the following treatments (5 weeks): soy-free diet (OVX), subcutaneously injected PTH (0.040 mg/kg) 5 days a week (PTH 5x/w), subcutaneously injected PTH (0.040 mg/kg) every 2 days (PTH e2d), and a sham group. The values of the biomechanical and histomorphometric parameters showed higher results in 5x/w animals in comparison to the OVX and PTH 2ed groups. The ratio between bone diameter/marrow diameter (B.Dm/Ma.Dm) in subtrochanteric cross sections did not show any significant differences between PTH 5x/w and PTH e2d. The increased bone formation rate was observed under PTH treatment in both groups mainly at the endosteal side. The endosteum seems here to be one of the targets of PTH with an accelerate bone formation and a pronounced filling-in of intracortical cavities with higher intensity for the PTH 5x/w in comparison to PTH e2d rats

Axonal pathfinding during the regeneration of the goldfish optic pathway

Retinal ganglion cells in fish and amphibians regenerate their axons after transection of the optic nerve. Fiber tracing studies during the third month of regeneration show that the axons have reestablished a basically normal fiber order in the two brachia of the optic tract; axons originating in the ventral hemiretina are concentrated in the dorsal brachium, axons from the dorsal hemiretina in the ventral brachium. Attardi and Sperry (Exp. Neurol. 7 :46–64, 1963) first suggested that the reestablishment of the fiber order reflects path-finding by the regenerating axons. Recently, however, Becker and Cook (Development 101 :323–337, 1987) have claimed that the fiber order observed at later stages of regeneration is due to secondary axonal rearrangements and that the initial brachial choice is random. In order to evaluate whether regenerating axons are capable of navigating in the optic tract and brachia and on the tectum, the present study examined the pathway choices and the morphology of regenerating axons en route to their tectal targets in goldfish. Subsets of axons were labeled at various time intervals (2 to 30 days) following an optic nerve crush, by intraretinal application of the lipophilic fluorescent tracer 1,1-dioctadecyl-3-3-3′-3′-tetra-methylcarbocyanine (DiI). After a survival time of 18 to 72 hours (to allow for diffusion of DiI along the axons), the experimental animals were perfused with fixative and their right and left optic pathways (nerve, tract, and tectum) were dissected free and separated at the chiasm. Fluorescently labeled axons were traced in whole-mounted pathways. Pathway choices were examined at the brachial bifurcation where axons from ventral and dorsal hemiretinae normally segregate. DiI was found to label axons reliably up to their growth cones, even at the earliest stages of regrowth. The pathway choices of the axons were nonrandom. The majority of the ventral axons reached the appropriate, dorsal hemitectum through the appropriate dorsal brachium of the tract. Dorsal axons reached the ventral hemitectum mainly through the ventral brachium. This suggests the presence of specific guidance cues, accessible to the regenerating axons. Differences in the complexity of the growth cones of the regenerating axons (simple in the nerve and tectal fiber layer, complex in the tract and the synaptic layer of the tectum) provide further evidence for specific interactions between the regenerating axons and their substrates along the pathway. These result argue that regenerating retinal axons in fish are capable of axonal path-finding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50045/1/902840109_ftp.pd