Dynamic Windows Scheduling with Reallocation

We consider the Windows Scheduling problem. The problem is a restricted version of Unit-Fractions Bin Packing, and it is also called Inventory Replenishment in the context of Supply Chain. In brief, the problem is to schedule the use of communication channels to clients. Each client ci is characterized by an active cycle and a window wi. During the period of time that any given client ci is active, there must be at least one transmission from ci scheduled in any wi consecutive time slots, but at most one transmission can be carried out in each channel per time slot. The goal is to minimize the number of channels used. We extend previous online models, where decisions are permanent, assuming that clients may be reallocated at some cost. We assume that such cost is a constant amount paid per reallocation. That is, we aim to minimize also the number of reallocations. We present three online reallocation algorithms for Windows Scheduling. We evaluate experimentally these protocols showing that, in practice, all three achieve constant amortized reallocations with close to optimal channel usage. Our simulations also expose interesting trade-offs between reallocations and channel usage. We introduce a new objective function for WS with reallocations, that can be also applied to models where reallocations are not possible. We analyze this metric for one of the algorithms which, to the best of our knowledge, is the first online WS protocol with theoretical guarantees that applies to scenarios where clients may leave and the analysis is against current load rather than peak load. Using previous results, we also observe bounds on channel usage for one of the algorithms.Comment: 6 figure

Empirical comparison of high gradient achievement for different metals in DC and pulsed mode

For the SwissFEL project, an advanced high gradient low emittance gun is under development. Reliable operation with an electric field, preferably above 125 MV/m at a 4 mm gap, in the presence of an UV laser beam, has to be achieved in a diode configuration in order to minimize the emittance dilution due to space charge effects. In the first phase, a DC breakdown test stand was used to test different metals with different preparation methods at voltages up to 100 kV. In addition high gradient stability tests were also carried out over several days in order to prove reliable spark-free operation with a minimum dark current. In the second phase, electrodes with selected materials were installed in the 250 ns FWHM, 500 kV electron gun and tested for high gradient breakdown and for quantum efficiency using an ultra-violet laser.Comment: 25 pages, 13 figures, 5 tables. Follow up from FEL 2008 conference (Geyongju Korea 2008) New Title in JVST A (2010) : Vacuum breakdown limit and quantum efficiency obtained for various technical metals using DC and pulsed voltage source

Rescue of DNA damage after constricted migration reveals a mechano-regulated threshold for cell cycle.

Migration through 3D constrictions can cause nuclear rupture and mislocalization of nuclear proteins, but damage to DNA remains uncertain, as does any effect on cell cycle. Here, myosin II inhibition rescues rupture and partially rescues the DNA damage marker γH2AX, but an apparent block in cell cycle appears unaffected. Co-overexpression of multiple DNA repair factors or antioxidant inhibition of break formation also exert partial effects, independently of rupture. Combined treatments completely rescue cell cycle suppression by DNA damage, revealing a sigmoidal dependence of cell cycle on excess DNA damage. Migration through custom-etched pores yields the same damage threshold, with ∼4-µm pores causing intermediate levels of both damage and cell cycle suppression. High curvature imposed rapidly by pores or probes or else by small micronuclei consistently associates nuclear rupture with dilution of stiff lamin-B filaments, loss of repair factors, and entry from cytoplasm of chromatin-binding cGAS (cyclic GMP-AMP synthase). The cell cycle block caused by constricted migration is nonetheless reversible, with a potential for DNA misrepair and genome variation

Photosynthetic variation and responsiveness to CO₂ in a widespread riparian tree

Phenotypic responses to rising CO2 will have consequences for the productivity and management of the world’s forests. This has been demonstrated through extensive free air and controlled environment CO2 enrichment studies. However intraspecific variation in plasticity remains poorly characterised in trees, with the capacity to produce unexpected trends in response to CO2 across a species distribution. Here we examined variation in photosynthesis traits across 43 provenances of a widespread, genetically diverse eucalypt, E. camaldulensis, under ambient and elevated CO2 conditions. Genetic variation suggestive of local adaptation was identified for some traits under ambient conditions. Evidence of genotype by CO2 interaction in responsiveness was limited, however support was identified for quantum yield (φ). In this case local adaptation was invoked to explain trends in provenance variation in response. The results suggest potential for genetic variation to influence a limited set of photosynthetic responses to rising CO2 in seedlings of E. camaldulensis, however further assessment in mature stage plants in linkage with growth and fitness traits is needed to understand whether trends in φ could have broader implications for productivity of red gum forests.This research was supported by funding from the CSIRO Transformational Biology Catalytic Platform. Experiments utilised the infrastructure of the Australian Plant Phenomics Facility, Canberra Australia

Paracrine effects of living human bone particles on the osteogenic differentiation of mesenchymal stem cells

Bone autografting remains the clinical model of choice for resolving problematic fractures. The precise mechanisms through which the autograft promotes bone healing are unknown. The present study examined the hypothesis that cells within the autograft secrete osteogenic factors promoting the differentiation of mesenchymal stem cells (MSCs) into osteoblasts. Particles of human bone (“chips”) were recovered at the time of joint replacement surgery and placed in culture. Then, conditioned media were added to cultures of human, adipose-derived MSCs under both basal and osteogenic conditions. Contrary to expectation, medium conditioned by bone chips reduced the expression of alkaline phosphatase and strongly inhibited mineral deposition by MSCs cultured in osteogenic medium. Real time PCR revealed the inhibition of collagen type I alpha 1 chain (Col1A1) and osteopontin (OPN) expression. These data indicated that the factors secreted by bone chips inhibited the osteogenic differentiation of MSCs. However, in late cultures, bone morphogenetic protein-2 (BMP-2) expression was stimulated, suggesting the possibility of a delayed, secondary osteogenic effect

Review of the advanced high-strength steels used in automotive industry

The objective of this paper was to present Advanced High-Strength Steels (AHSS) and their manufacturing processes, as well as to emphasize their complexity. The AHSSs were created as a solution to reduce the weight of parts and structures in transportation industries (automotive, airplane and truck industry). Regarding the development of the AHSSs, it was divided in three generation. Besides implementation of materials with higher strength, lower mass of structures could be achieved by application of materials of a lower density (e.g., aluminium and titanium). Application of the lightweight materials directly results in lowering the structures’ mass, and it positively affects energy efficiency, preservation of the environment and lowering the pollution levels. However, there are still numerous problems and disadvantages, related to the application of lightweight materials, primarily with processing (low machinability, deformability, as well as weldability). Besides the processing problems, mentioned materials have higher prices than steel; therefore, development of new steel grades, as well as development of new methods for realizing the higher strength was initiated. It is already well known from the literature that by implementing the selected heat treatment procedures (varying the heating and cooling regimes), the steel properties could be altered. It was thus concluded that combination of the heat treatment and plastic deformation in steel production can result in increasing the steel strength, while simultaneously keeping the good deformability and even weldability.The authors wish to acknowledge the financial support from the Ministry of Education and Science of the Republic of Serbia through the project Grant TR32036 and TR35024 and by the project of Operational Programme Integrated Infrastructure “Support of research and development capacities to generate advanced software tools designed to increase the resilience of economic entities against excessive volatility of the energy commodity market”, ITMS2014+ code 313011BUK9, co-funded by European Regional Development Fund.Publishe

The use of mesenchymal stem cells for cartilage repair and regeneration: a systematic review.

BACKGROUND: The management of articular cartilage defects presents many clinical challenges due to its avascular, aneural and alymphatic nature. Bone marrow stimulation techniques, such as microfracture, are the most frequently used method in clinical practice however the resulting mixed fibrocartilage tissue which is inferior to native hyaline cartilage. Other methods have shown promise but are far from perfect. There is an unmet need and growing interest in regenerative medicine and tissue engineering to improve the outcome for patients requiring cartilage repair. Many published reviews on cartilage repair only list human clinical trials, underestimating the wealth of basic sciences and animal studies that are precursors to future research. We therefore set out to perform a systematic review of the literature to assess the translation of stem cell therapy to explore what research had been carried out at each of the stages of translation from bench-top (in vitro), animal (pre-clinical) and human studies (clinical) and assemble an evidence-based cascade for the responsible introduction of stem cell therapy for cartilage defects. This review was conducted in accordance to PRISMA guidelines using CINHAL, MEDLINE, EMBASE, Scopus and Web of Knowledge databases from 1st January 1900 to 30th June 2015. In total, there were 2880 studies identified of which 252 studies were included for analysis (100 articles for in vitro studies, 111 studies for animal studies; and 31 studies for human studies). There was a huge variance in cell source in pre-clinical studies both of terms of animal used, location of harvest (fat, marrow, blood or synovium) and allogeneicity. The use of scaffolds, growth factors, number of cell passages and number of cells used was hugely heterogeneous. SHORT CONCLUSIONS: This review offers a comprehensive assessment of the evidence behind the translation of basic science to the clinical practice of cartilage repair. It has revealed a lack of connectivity between the in vitro, pre-clinical and human data and a patchwork quilt of synergistic evidence. Drivers for progress in this space are largely driven by patient demand, surgeon inquisition and a regulatory framework that is learning at the same pace as new developments take place

The presence and regulation of connective tissue growth factor in the human endometrium

The potential of a solid-phase asymmetric resin-capture-release strategy for high-throughput synthesis has been evaluated. Fukuzawa's Sm(II)-mediated, asymmetric approach to γ-butyrolactones was selected to illustrate the feasibility of such a process. α,β-Unsaturated esters immobilised on an ephedrine chiral resin have been applied in an asymmetric approach to γ-butyrolactones. Lactone products are obtained in moderate isolated yields with selectivities up to 96% ee. In addition, we have shown that the ephedrine resin can be conveniently recovered and recycled although in some cases lower yields were obtained on reuse of the chiral resin. A short synthesis of a moderate DNA-binding microbial metabolite using asymmetric resin-capture-release is also described

Hydrometeorological multi-model ensemble simulations of the 4 November 2011 flash flood event in Genoa, Italy, in the framework of the DRIHM Project

The e-Science environment developed in the framework of the EU-funded DRIHM project was used to demonstrate its ability to provide relevant, meaningful hydrometeorological forecasts. This was illustrated for the tragic case of 4 November 2011, when Genoa, Italy, was flooded as the result of heavy, convective precipitation that inundated the Bisagno catchment. The Meteorological Model Bridge (MMB), an innovative software component developed within the DRIHM project for the interoperability of meteorological and hydrological models, is a key component of the DRIHM e-Science environment. The MMB allowed three different rainfall-discharge models (DRiFt, RIBS and HBV) to be driven by four mesoscale limited-area atmospheric models (WRF-NMM, WRF-ARW, Meso-NH and AROME) and a downscaling algorithm (RainFARM) in a seamless fashion. In addition to this multi-model configuration, some of the models were run in probabilistic mode, thus giving a comprehensive account of modelling errors and a very large amount of likely hydrometeorological scenarios (> 1500). The multi-model approach proved to be necessary because, whilst various aspects of the event were successfully simulated by different models, none of the models reproduced all of these aspects correctly. It was shown that the resulting set of simulations helped identify key atmospheric processes responsible for the large rainfall accumulations over the Bisagno basin. The DRIHM e-Science environment facilitated an evaluation of the sensitivity to atmospheric and hydrological modelling errors. This showed that both had a significant impact on predicted discharges, the former being larger than the latter. Finally, the usefulness of the set of hydrometeorological simulations was assessed from a flash flood early-warning perspective