Gas-injection valve operates at high speed

Fast acting gas valve is used for injecting a short pulse of gas into a vacuum chamber during plasma acceleration experiments. It contains a lightweight closure disk that is forced away from the valve seat when an electromagnetic coil is momentarily energized and immediately rebounds from a stop back onto the seat

Antimicrobial activity of flavonoid extracts from Sabah tea (Camellia sinensis) against Escherichia coli and Listeria monocytogenes

The antimicrobial activity of tea (Camellia sinensis) flavonoids against selected foodborne pathogens, Escherichia coli 0157:H7 and Listeria monocytogenes was studied. Flavonoid, hydrolysed flavonoid, flavanol and crude catechin were extracted from fresh and dried tea leaf samples. The activities of each extract on both pathogens were tested using paper disc diffusion method. Extracts producing inhibition zone of more than 8.0 mm were further investigated to determine their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Hydrolysed flavonoid of dried samples was the most active extract against E. coli O157:H7 and L. monocytogenes with inhibition zone of 16.0 ± 1.4 mm and 22.0 ± 1.4 mm respectively. The MIC of hydrolysed flavonoid extract from fresh samples on E. coli O157:H7 was 9.7 mg/ml while the MBC was 11.7 mg/ml. Listeria monocytogenes was inhibited at a minimum concentration of 5.86 mg/ml by the same extract. Crude catechin from fresh sample was less effective in controlling L. monocytogenes with a MIC of 93.8 mg/ml, which was also its MBC. The time required for the reduction of L. monocytogenes count by one log cycle was the shortest (1.87 h) in the presence of hydrolysed flavonoid extract at MBC (6.83 mg/ml)

A Context Gathering Framework for Context-Aware Mobile Solutions

One of the fundamental design issues in context-aware mobile services development is the necessary support for adequately powerful yet efficient querying of the sensory data. This issue argues for research into the creation of a technology-independent, high-level software application programming interface (API) that provides mechanisms for dealing with the heterogeneity of sensors providing raw context data. In this paper, we review approaches in existing context-aware platforms especially those that consider with sensory data acquisition. The review formed the basis for the design and development of the context gathering framework which consists of sensor data model, messaging and communication protocol and software application programming interface. These components form as one of the enabler to support the development of context aware mobile applications

Mission-oriented requirements for updating MIL-H-8501. Volume 2: STI background and rationale

A supplement to the structure of a new flying and ground handling qualities specification for military rotorcraft structure is presented in order to explain the background and rationale for the specification structure, the proposed forms of criteria, and the status of the existing data base. Critical gaps in the data base for the new structure are defined, and recommendations are provided for the research required to address the most important of these gaps

Modeling hydrodynamic self-propulsion with Stokesian Dynamics. Or teaching Stokesian Dynamics to swim

We develop a general framework for modeling the hydrodynamic self-propulsion (i.e., swimming) of bodies (e.g., microorganisms) at low Reynolds number via Stokesian Dynamics simulations. The swimming body is composed of many spherical particles constrained to form an assembly that deforms via relative motion of its constituent particles. The resistance tensor describing the hydrodynamic interactions among the individual particles maps directly onto that for the assembly. Specifying a particular swimming gait and imposing the condition that the swimming body is force- and torque-free determine the propulsive speed. The body’s translational and rotational velocities computed via this methodology are identical in form to that from the classical theory for the swimming of arbitrary bodies at low Reynolds number. We illustrate the generality of the method through simulations of a wide array of swimming bodies: pushers and pullers, spinners, the Taylor=Purcell swimming toroid, Taylor’s helical swimmer, Purcell’s three-link swimmer, and an amoeba-like body undergoing large-scale deformation. An open source code is a part of the supplementary material and can be used to simulate the swimming of a body with arbitrary geometry and swimming gait

Comparison of Post-injection Site Pain Between Technetium Sulfur Colloid and Technetium Tilmanocept in Breast Cancer Patients Undergoing Sentinel Lymph Node Biopsy.

BackgroundNo prior studies have examined injection pain associated with Technetium-99m Tilmanocept (TcTM).MethodsThis was a randomized, double-blinded study comparing postinjection site pain between filtered Technetium Sulfur Colloid (fTcSC) and TcTM in breast cancer lymphoscintigraphy. Pain was evaluated with a visual analogue scale (VAS) (0-100 mm) and the short-form McGill Pain Questionnaire (SF-MPQ). The primary endpoint was mean difference in VAS scores at 1-min postinjection between fTcSC and TcTM. Secondary endpoints included a comparison of SF-MPQ scores between the groups at 5 min postinjection and construction of a linear mixed effects model to evaluate the changes in pain during the 5-min postinjection period.ResultsFifty-two patients underwent injection (27-fTcSC, 25-TcTM). At 1-min postinjection, patients who received fTcSC experienced a mean change in pain of 16.8 mm (standard deviation (SD) 19.5) compared with 0.2 mm (SD 7.3) in TcTM (p = 0.0002). At 5 min postinjection, the mean total score on the SF-MPQ was 2.8 (SD 3.0) for fTcSC versus 2.1 (SD 2.5) for TcTM (p = 0.36). In the mixed effects model, injection agent (p < 0.001), time (p < 0.001) and their interaction (p < 0.001) were associated with change in pain during the 5-min postinjection period. The model found fTcSC resulted in significantly more pain of 15.2 mm (p < 0.001), 11.3 mm (p = 0.001), and 7.5 mm (p = 0.013) at 1, 2, and 3 min postinjection, respectively.ConclusionsInjection with fTcSC causes significantly more pain during the first 3 min postinjection compared with TcTM in women undergoing lymphoscintigraphy for breast cancer

TEAM: efficient two-locus epistasis tests in human genome-wide association study

As a promising tool for identifying genetic markers underlying phenotypic differences, genome-wide association study (GWAS) has been extensively investigated in recent years. In GWAS, detecting epistasis (or gene–gene interaction) is preferable over single locus study since many diseases are known to be complex traits. A brute force search is infeasible for epistasis detection in the genome-wide scale because of the intensive computational burden. Existing epistasis detection algorithms are designed for dataset consisting of homozygous markers and small sample size. In human study, however, the genotype may be heterozygous, and number of individuals can be up to thousands. Thus, existing methods are not readily applicable to human datasets. In this article, we propose an efficient algorithm, TEAM, which significantly speeds up epistasis detection for human GWAS. Our algorithm is exhaustive, i.e. it does not ignore any epistatic interaction. Utilizing the minimum spanning tree structure, the algorithm incrementally updates the contingency tables for epistatic tests without scanning all individuals. Our algorithm has broader applicability and is more efficient than existing methods for large sample study. It supports any statistical test that is based on contingency tables, and enables both family-wise error rate and false discovery rate controlling. Extensive experiments show that our algorithm only needs to examine a small portion of the individuals to update the contingency tables, and it achieves at least an order of magnitude speed up over the brute force approach

Mission-oriented requirements for updating MIL-H-8501. Volume 1: STI proposed structure

The structure of a new flying and ground handling qualities specification for military rotorcraft is presented. This preliminary specification structure is intended to evolve into a replacement for specification MIL-H-8501A. The new structure is designed to accommodate a variety of rotorcraft types, mission flight phases, flight envelopes, and flight environmental characteristics and to provide criteria for three levels of flying qualities, a systematic treatment of failures and reliability, both conventional and multiaxis controllers, and external vision aids which may also incorporate synthetic display content. Existing and new criteria were incorporated into the new structure wherever they could be substantiated

Valley-spin blockade and spin resonance in carbon nanotubes

Manipulation and readout of spin qubits in quantum dots made in III-V materials successfully rely on Pauli blockade that forbids transitions between spin-triplet and spin-singlet states. Quantum dots in group IV materials have the advantage of avoiding decoherence from the hyperfine interaction by purifying them with only zero-spin nuclei. Complications of group IV materials arise from the valley degeneracies in the electronic bandstructure. These lead to complicated multiplet states even for two-electron quantum dots thereby significantly weakening the selection rules for Pauli blockade. Only recently have spin qubits been realized in silicon devices where the valley degeneracy is lifted by strain and spatial confinement. In carbon nanotubes Pauli blockade can be observed by lifting valley degeneracy through disorder. In clean nanotubes, quantum dots have to be made ultra-small to obtain a large energy difference between the relevant multiplet states. Here we report on low-disorder nanotubes and demonstrate Pauli blockade based on both valley and spin selection rules. We exploit the bandgap of the nanotube to obtain a large level spacing and thereby a robust blockade. Single-electron spin resonance is detected using the blockade.Comment: 31 pages including supplementary informatio