Task Scheduling with RT Constraints

This paper addresses the problem of scheduling reactive realtime transactions (task groups) implementing a network of extended Finite State Machines communicating asynchronously. Task instances are..

Relations among mechanical properties, collagen fibers, and calcification in adult human cortical bone

The relations of ultimate tensile stress and strain and modulus of elasticity to collagen fiber orientation and degree of calcification were studied in thirty-six standardized specimens of unembalmed cortical bone from adult human tibias. Highly significant positive correlations were found between tensile stress and strain and percentage of dark osteons in the break area. A similar correlation occurred between tensile strain and dark osteons plus fragments. Tensile stress and strain had highly significant negative correlations with light osteons and their fragments but a lower negative correlation with intermediate osteons. Significant negative correlations were found between the intermediate radiolucent and the marked radiolucent osteons and tensile stress and strain, respectively. Partialing out interstitial lamellae and intermediate radiolucent areas revealed significant positive and negative correlations between tensile stress and dark and light osteons, respectively. No significant correlations occurred between modulus of elasticity and any of the histological variables.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33658/1/0000168.pd

Relations of the compressive properties of human cortical bone to histological structure and calcification

Compressive properties were determined for 65 standardized specimens of wet, unembalmed cortical bone from tibias of six men. Osteons were classified as dark, light or intermediate from their appearance in polarized light and as slightly, intermediately or markedly radiolucent from their appearance in microradiographs. Compressive strength had significant positive correlations with the percent of intermediate osteons or slightly radiolucent osteons in the cross section. Significant negative correlations occurred between compressive strength and percent of spaces. Compressive strain had a significant positive correlation with the percent of light osteons. Multiple correlation coefficients between compressive strength or strain and the various histologic and microradiographic variables were higher and more significant than that found with elastic modulus as the dependent variable. The significant positive correlation between compressive strength and the percent of osteons, regardless of their collagen fiber orientation in the cross-section, suggests that osteons tend to increase the compressive strength of bone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22429/1/0000879.pd

Relation of collagen fiber orientation to some mechanical properties of human cortical bone

The percentage of dark, light, and intermediate osteons and their fragments, as seen in polarized light, was determined for 53 cross-sections of embalmed, adult human bone. Dark osteons have collagen fibers predominantly parallel with the long axis of the osteon while in light osteons the fibers are at a sharp angle to the long axis of the osteon. Intermediate osteons are mixed.Significant positive correlations were found between dark osteons alone, as well as when combined with their fragments, and the single shearing strength. Intermediate osteons alone, and when combined with their fragments, showed significant positive correlations with the (1) single shearing strength, (2) modulus of elasticity, and (3) percent elongation.Significant negative correlations were found between light osteons alone, and when combined with their fragments, and the (1) single shearing strength and (2) modulus of elasticity.No other significant correlations were found among the various types of osteons alone, or when combined with their fragments, and the mechanical properties of the specimens.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33002/1/0000386.pd

Correlating spectral and timing properties in the evolving jet of the micro blazar MAXI J1836-194

During outbursts, the observational properties of black hole X-ray binaries (BHXBs) vary on timescales of days to months. These relatively short timescales make these systems ideal laboratories to probe the coupling between accreting material and outflowing jets as a the accretion rate varies. In particular, the origin of the hard X-ray emission is poorly understood and highly debated. This spectral component, which has a power-law shape, is due to Comptonisation of photons near the black hole, but it is unclear whether it originates in the accretion flow itself, or at the base of the jet, or possibly the interface region between them. In this paper we explore the disk-jet connection by modelling the multi-wavelength emission of MAXI J1836-194 during its 2011 outburst. We combine radio through X-ray spectra, X-ray timing information, and a robust joint-fitting method to better isolate the jet's physical properties. Our results demonstrate that the jet base can produce power-law hard X-ray emission in this system/outburst, provided that its base is fairly compact and that the temperatures of the emitting electrons are sub-relativistic. Because of energetic considerations, our model favours mildly pair-loaded jets carrying at least 20 pairs per proton. Finally, we find that the properties of the X-ray power spectrum are correlated with the jet properties, suggesting that an underlying physical process regulates both.Comment: 17 pages, 10 figures, accepted for publication on MNRA

A008 Presence of tissue factor and other components of atherosclerosis in human aortic valve stenosis

BackgroundIt is now generally accepted that calcific aortic valve disease is an atherosclerotic-like process. Recent studies in an experimental model of aortic valve sclerosis demonstrated the presence of tissue factor (TF), the main contributor to atherosclerotic plaque thrombogenicity, in diseased valve leaflets. We assessed the hypothesis that human aortic valve disease is an atherosclerotic-like process in which TF plays an important role and evaluated the valvular expression and localization of TF and other components of atherosclerosis.MethodsCalcified aortic valves (n=52) were obtained from patients undergoing aortic valve replacement. Leaflet structure, cellular and lipid infiltration and expression of TF, its inhibitors, VEGF and other components of atherosclerosis were evaluated by histological and immunohistochemical staining. TF, TFPI, osteopontin, MMP- 9, TIMP-1 and VEGF antigen were measured by ELISA and TF and alkaline phosphatase activity were determined using chromogenic assays. Finally, we performed semi-quantification of TF transcripts by RT- PCR and further analyzed protein expression by Western blot.ResultsHistological and immunohistochemical staining of the valve leaflets revealed neovascularisation at the centre of the lesions, overall macrophage and myofibroblast infiltration and the abundant presence of MMP-9. On the other hand, TF and TFPI were associated with calcification and extracellular lipid deposits in the fibrosa and the subendothelial layer of the aortic side of the leaflets. Correspondingly, TF antigen and activity were found to be higher in calcified regions of the valve leaflets (733.29±70.49pg/mgvs 429.40±73.17pg/mg and 144.75±14.65pg/mgvs 40.15±6.19pg/mg respectively (p<0.0001)). Similar results were found for osteopontin, MMP-9, TIMP-1 and VEGF. In contrast, TFPI antigen was found to be much lower in these calcified regions (722.54±153.92pg/mgvs 2459.28±285.36pg/mg (p<0.0001)).ConclusionThese results demonstrate that aortic valve lesions display several characteristics of atherosclerosis, including TF expression. In addition, we showed that TF is colocalized with calcification and lipid deposition. Further studies are now set up to evaluate the role of TF in aortic valve disease and its association with other components of the atherosclerotic process

Peering at the outflow mechanisms in the transitional pulsar PSR J1023+0038: simultaneous VLT, XMM-Newton, and Swift high-time resolution observations

We report on a NIR, optical and X-ray campaign performed in 2017 with the XMM-Newton and Swift satellites and the VLT/HAWK-I instrument on the transitional MSP PSR J1023+0038. NIR observations were performed in fast-photometric mode in order to detect any fast variation of the flux and correlate them with the optical and X-ray light curves. The optical curve shows the typical sinusoidal modulation at the orbital period (4.75hr). No flaring or flickering is found in the optical, neither signs of transitions between active and passive states. On the contrary, the NIR curve displays a bimodal behaviour, showing strong flares in the first part of the curve, and an almost flat trend in the rest. The X-ray curves show a few low/high mode transitions, but no flaring activity. One of the low/high mode transition is found to happen at the same time as the emission of an infrared flare. This can be interpreted as the emission of a jet: the NIR flare could be due to the evolving spectrum of the jet, which possesses a break frequency that moves from higher (NIR) to lower (radio) frequencies after the launching, that has to happen at the low/high mode transition. We also present the cross correlation function between the optical and near infrared curves. Due to the bimodality of the NIR curve, we divided it in two parts (flaring and quiet). While the CCF of the quiet part is found to be flat, the one referring to the flaring part shows a narrow peak at ~10s, which indicates a delay of the NIR emission with respect to the optical. This lag can be interpreted as reprocessing of the optical emission at the light cylinder radius with a stream of matter spiraling around the system due to a phase of radio-ejection. This strongly supports a different origin of the NIR flares observed for PSR J1023+0038 with respect to the optical and X-ray flaring activity reported in other works on the same source.Comment: 10 pages, 9 figures. Accepted for publication in Astronomy&Astrophysic

Let’s Get Physical: Computer Science Meets Systems

In cyber-physical systems (CPS) computing, networking and control (typically regarded as the "cyber" part of the system) are tightly intertwined with mechanical, electrical, thermal, chemical or biological processes (the "physical" part). The increasing sophistication and heterogeneity of these systems requires radical changes in the way sense-and-control platforms are designed to regulate them. In this paper, we highlight some of the design challenges due to the complexity and heterogeneity of CPS. We argue that such challenges can be addressed by leveraging concepts that have been instrumental in fostering electronic design automation while dealing with complexity in VLSI system design. Based on these concepts, we introduce a design methodology whereby platform-based design is combined with assume-guarantee contracts to formalize the design process and enable realization of CPS architectures and control software in a hierarchical and compositional manner. We demonstrate our approach on a prototype design of an aircraft electric power system. © 2014 Springer-Verlag Berlin Heidelberg

Generation of a library of carbohydrate-active enzymes for plant biomass deconstruction

Áreas de pesquisa: Biochemistry & Molecular Biology ; ChemistryIn nature, the deconstruction of plant carbohydrates is carried out by carbohydrate-active enzymes (CAZymes). A high-throughput (HTP) strategy was used to isolate and clone 1476 genes obtained from a diverse library of recombinant CAZymes covering a variety of sequence-based families, enzyme classes, and source organisms. All genes were successfully isolated by either PCR (61%) or gene synthesis (GS) (39%) and were subsequently cloned into Escherichia coli expression vectors. Most proteins (79%) were obtained at a good yield during recombinant expression. A significantly lower number (p < 0.01) of proteins from eukaryotic (57.7%) and archaeal (53.3%) origin were soluble compared to bacteria (79.7%). Genes obtained by GS gave a significantly lower number (p = 0.04) of soluble proteins while the green fluorescent protein tag improved protein solubility (p = 0.05). Finally, a relationship between the amino acid composition and protein solubility was observed. Thus, a lower percentage of non-polar and higher percentage of negatively charged amino acids in a protein may be a good predictor for higher protein solubility in E. coli. The HTP approach presented here is a powerful tool for producing recombinant CAZymes that can be used for future studies of plant cell wall degradation. Successful production and expression of soluble recombinant proteins at a high rate opens new possibilities for the high-throughput production of targets from limitless sourcesinfo:eu-repo/semantics/publishedVersio