ASIdE: Using Autocorrelation-Based Size Estimation for Scheduling Bursty Workloads.

Temporal dependence in workloads creates peak congestion that can make service unavailable and reduce system performance. To improve system performability under conditions of temporal dependence, a server should quickly process bursts of requests that may need large service demands. In this paper, we propose and evaluateASIdE, an Autocorrelation-based SIze Estimation, that selectively delays requests which contribute to the workload temporal dependence. ASIdE implicitly approximates the shortest job first (SJF) scheduling policy but without any prior knowledge of job service times. Extensive experiments show that (1) ASIdE achieves good service time estimates from the temporal dependence structure of the workload to implicitly approximate the behavior of SJF; and (2) ASIdE successfully counteracts peak congestion in the workload and improves system performability under a wide variety of settings. Specifically, we show that system capacity under ASIdE is largely increased compared to the first-come first-served (FCFS) scheduling policy and is highly-competitive with SJF. © 2012 IEEE

Evaporation of microdroplets of azeotropic liquids

This work reports data showing the evolution of contact angle with time for mixtures of water and 1-propanol at room temperature on poly(methyl methacrylate) (PMMA). The composition range investigated spans the azeotropic composition, thus encompassing systems containing excess water and excess 1-propanol. A discontinuity in the contact angle behavior is observed and it is suggested that this enables the identification of the azeotropic composition as 0.39 mole fraction of 1-propanol. This suggestion is supported by boiling point measurements made at around 20 mmHg. The discontinuity is associated with the presence of an instability, which causes a distortion around the droplet perimeter. It is suggested that the distortion is caused by competing effects of local surface tension maxima and minima

Claspin and the Activated Form of ATR-ATRIP Collaborate in the Activation of Chk1

Claspin is necessary for the ATR-dependent activation of Chk1 in Xenopus egg extracts containing incompletely replicated DNA. ATR possesses a regulatory partner called ATRIP. We have studied the respective roles of ATR-ATRIP and Claspin in the activation of Chk1. ATR-ATRIP bound well to various DNA templates in Xenopus egg extracts. ATR-ATRIP bound to a single-stranded DNA template was weakly active. By contrast, the ATR-ATRIP complex on a DNA template containing both single- and double-stranded regions displayed a large increase in kinase activity. This observation suggests that ATR-ATRIP normally undergoes activation upon association with specific nucleic acid structures at DNA replication forks. Without Claspin, activated ATR-ATRIP phosphorylated Chk1 weakly in a cell-free reaction. The addition of Claspin to this reaction strongly stimulated the phosphorylation of Chk1 by ATR-ATRIP. Claspin also induced significant autophosphorylation of Chk1 in the absence of ATR-ATRIP. Taken together, these results indicate that the checkpoint-dependent phosphorylation of Chk1 is a multistep process involving activation of the ATR-ATRIP complex at replication forks and presentation of Chk1 to this complex by Claspin

Pulse mode operation of Love wave devices for biosensing applications

In this work we present a novel pulse mode Love wave biosensor that monitors both changes in amplitude and phase. A series of concentrations of 3350 molecular weight poly(ethylene glycol) (PEG) solutions are used as a calibration sequence for the pulse mode system using a network analyzer and high frequency oscilloscope. The operation of the pulse mode system is then compared to the continuous wave network analyzer by showing a sequence of deposition and removal of a model mass layer of palmitoyl-oleoyl-sn-glycerophosphocholine (POPC) vesicles. This experimental apparatus has the potential for making many hundreds of measurements a minute and so allowing the dynamics of fast interactions to be observed

High Resolution Valley Spectroscopy of Si Quantum Dots

We study an accumulation mode Si/SiGe double quantum dot (DQD) containing a single electron that is dipole coupled to microwave photons in a superconducting cavity. Measurements of the cavity transmission reveal dispersive features due to the DQD valley states in Si. The occupation of the valley states can be increased by raising temperature or applying a finite source-drain bias across the DQD, resulting in an increased signal. Using cavity input-output theory and a four-level model of the DQD, it is possible to efficiently extract valley splittings and the inter- and intra-valley tunnel couplings

Interplay of Superconductivity and Spin-Dependent Disorder

The finite temperature phase diagram for the 2D attractive fermion Hubbard model with spin-dependent disorder is considered within Bogoliubov-de Gennes mean field theory. Three types of disorder are studied. In the first, only one species is coupled to a random site energy; in the second, the two species both move in random site energy landscapes which are of the same amplitude, but different realizations; and finally, in the third, the disorder is in the hopping rather than the site energy. For all three cases we find that, unlike the case of spin-symmetric randomness, where the energy gap and average order parameter do not vanish as the disorder strength increases, a critical disorder strength exists separating distinct phases. In fact, the energy gap and the average order parameter vanish at distinct transitions, $V_{c}^{\rm gap}$ and $V_{c}^{\rm op}$, allowing for a gapless superconducting (gSC) phase. The gSC phase becomes smaller with increasing temperature, until it vanishes at a temperature $T^{\ast}$.Comment: 9 pages, 7 figure

Influence of viscoelasticity and interfacial slip on acoustic wave sensors

Acoustic wave devices with shear horizontal displacements, such as quartz crystal microbalances (QCM) and shear horizontally polarised surface acoustic wave (SH-SAW) devices provide sensitive probes of changes at solid-solid and solid- liquid interfaces. Increasingly the surfaces of acoustic wave devices are being chemically or physically modified to alter surface adhesion or coated with one or more layers to amplify their response to any change of mass or material properties. In this work, we describe a model that provides a unified view of the modification in the shear motion in acoustic wave systems by multiple finite thickness loadings of viscoelastic fluids. This model encompasses QCM and other classes of acoustic wave devices based on a shear motion of the substrate surface and is also valid whether the coating film has a liquid or solid character. As a specific example, the transition of a coating from liquid to solid is modelled using a single relaxation time Maxwell model. The correspondence between parameters from this physical model and parameters from alternative acoustic impedance models is given explicitly. The characteristic changes in QCM frequency and attenuation as a function of thickness are illustrated for a single layer device as the coating is varied from liquid-like to that of an amorphous solid. Results for a double layer structure are given explicitly and the extension of the physical model to multiple layers is described

Strategic Asset Seeking and Innovation Performance: The Role of Innovation Capabilities and Host Country Institutions

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Painful shoulder? Remote clinical management of a field guide with shoulder pain and loss of shoulder function in Antarctica

© 2017, Australasian Medical Journal Pty Ltd. All rights reserved. We report the case of a female Field Guide based at the British Antarctic Survey’s Rothera Science Research Station on Adelaide Island, Antarctica who independently contacted a physiotherapist specialising in climbing related injuries (GJ) located in the UK. For a second opinion. The Field Guide was experiencing significant work difficulties due to shoulder pain and subsequent loss of function particularly in overhead activities. The case raises important issues about the medical management of Field Guides operating in extreme environments and remote locations

Phosphorylation of Chk1 by ATM- and Rad3-related (ATR) in Xenopus Egg Extracts Requires Binding of ATRIP to ATR but Not the Stable DNA-binding or Coiled-coil Domains of ATRIP

ATR, a critical regulator of DNA replication and damage checkpoint responses, possesses a binding partner called ATRIP. We have studied the functional properties of Xenopus ATR and ATRIP in incubations with purified components and in frog egg extracts. In purified systems, ATRIP associates with DNA in both RPA-dependent and RPA-independent manners, depending on the composition of the template. However, in egg extracts, only the RPA-dependent mode of binding to DNA can be detected. ATRIP adopts an oligomeric state in egg extracts that depends upon binding to ATR. In addition, ATR and ATRIP are mutually dependent on one another for stable binding to DNA in egg extracts. The ATR-dependent oligomerization of ATRIP does not require an intact coiled-coil domain in ATRIP and does not change in the presence of checkpoint-inducing DNA templates. Egg extracts containing a mutant of ATRIP that cannot bind to ATR are defective in the phosphorylation of Chk1. However, extracts containing mutants of ATRIP lacking stable DNA-binding and coiled-coil domains show no reduction in the phosphorylation of Chk1 in response to defined DNA templates. Furthermore, activation of Chk1 does not depend upon RPA under these conditions. These results suggest that ATRIP must associate with ATR in order for ATR to carry out the phosphorylation of Chk1 effectively. However, this function of ATRIP does not involve its ability to mediate the stable binding of ATR to defined checkpoint-inducing DNA templates in egg extracts, does not require an intact coiled-coil domain, and does not depend on RPA