453 research outputs found

    An inkjet printed, roll-coated digital microfluidic device for inexpensive, miniaturized diagnostic assays

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    The diagnosis of infectious disease is typically carried out at the point-of-care (POC) using the lateral flow assay (LFA). While cost-effective and portable, LFAs often lack the clinical sensitivity and specificity required for accurate diagnoses. In response to this challenge, we introduce a new digital microfluidic (DMF) platform fabricated using a custom inkjet printing and roll-coating process that is scalable to mass production. The performance of the new devices is on par with that of traditional DMF devices fabricated in a cleanroom, with a materials cost for the new devices of only US $0.63 per device. To evaluate the usefulness of the new platform, we performed a 13-step rubella virus (RV) IgG immunoassay on the inkjet printed, roll-coated devices, which yielded a limit of detection of 0.02 IU mL^(−1), well below the diagnostic cut-off of 10 IU mL^(−1) for RV infection and immunity. We propose that this represents a breakthrough for DMF, lowering the costs to a level such that the new platforms will be an attractive alternative to LFAs for the diagnosis of infectious disease at the POC

    A DNA-binding bromodomain-containing protein interacts with and reduces Rx1-mediated immune response to Potato Virus X

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    Plant NLR proteins enable the immune system to recognise and respond to pathogen attack. An early consequence of immune activation is transcriptional reprogramming. Some NLRs have been shown to act in the nucleus and interact with transcription factors. The Rx1 NLR protein of potato binds and distorts double-stranded DNA. However, the components of the chromatin localized Rx1-complex are largely unknown. Here we report a physical and functional interaction between Rx1 and NbDBCP, a bromodomain-containing chromatin-interacting protein. NbDBCP accumulates in the nucleolus, interacts with chromatin and redistributes Rx1 to the nucleolus in a subpopulation of imaged cells. Rx1 over-expression reduces NbDBCP interactions with chromatin. NbDBCP is a negative regulator of Rx1-mediated immune responses to potato virus X (PVX) and this activity requires an intact bromodomain. Previously, Rx1 has been shown to regulate the DNA-binding activity of a Golden2-like transcription factor, NbGlk1. Rx1 and NbDBCP act synergistically to reduce NbGlk1 DNA-binding suggesting a mode of action for NbDBCP’s inhibitory effect on immunity. This study provides new mechanistic insight into how a chromatin localised NLR complex co-ordinates immune signalling following pathogen perception

    An inkjet printed, roll-coated digital microfluidic device for inexpensive, miniaturized diagnostic assays

    Get PDF
    The diagnosis of infectious disease is typically carried out at the point-of-care (POC) using the lateral flow assay (LFA). While cost-effective and portable, LFAs often lack the clinical sensitivity and specificity required for accurate diagnoses. In response to this challenge, we introduce a new digital microfluidic (DMF) platform fabricated using a custom inkjet printing and roll-coating process that is scalable to mass production. The performance of the new devices is on par with that of traditional DMF devices fabricated in a cleanroom, with a materials cost for the new devices of only US $0.63 per device. To evaluate the usefulness of the new platform, we performed a 13-step rubella virus (RV) IgG immunoassay on the inkjet printed, roll-coated devices, which yielded a limit of detection of 0.02 IU mL^(−1), well below the diagnostic cut-off of 10 IU mL^(−1) for RV infection and immunity. We propose that this represents a breakthrough for DMF, lowering the costs to a level such that the new platforms will be an attractive alternative to LFAs for the diagnosis of infectious disease at the POC

    A conceptual design study for a two-dimensional, electronically scanned thinned array radiometer

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    A conceptual design for the Two-Dimensional, Electronically Steered Thinned Array Radiometer (ESTAR) is described. This instrument is a synthetic aperture microwave radiometer that operates in the L-band frequency range for the measurement of soil moisture and ocean salinity. Two auxiliary instruments, an 8-12 micron, scanning infrared radiometer and a 0.4-1.0 micron, charge coupled device (CCD) video camera, are included to provided data for sea surface temperature measurements and spatial registration of targets respectively. The science requirements were defined by Goddard Space Flight Center. Instrument and the spacecraft configurations are described for missions using the Pegasus and Taurus launch vehicles. The analyses and design trades described include: estimations of size, mass and power, instrument viewing coverage, mechanical design trades, structural and thermal analyses, data and communications performance assessments, and cost estimation

    Linking Physical Activity to Breast Cancer via Sex Steroid Hormones, Part 2:The Effect of Sex Steroid Hormones on Breast Cancer Risk

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    We undertook a systematic review and appraised the evidence for an effect of circulating sex steroid hormones and sex hormone–binding globulin (SHBG) on breast cancer risk in pre- and postmenopausal women. Systematic searches identified prospective studies relevant to this review. Meta-analyses estimated breast cancer risk for women with the highest compared with the lowest level of sex hormones, and the DRMETA Stata package was used to graphically represent the shape of these associations. The ROBINS-E tool assessed risk of bias, and the GRADE system appraised the strength of evidence. In premenopausal women, there was little evidence that estrogens, progesterone, or SHBG were associated with breast cancer risk, whereas androgens showed a positive association. In postmenopausal women, higher estrogens and androgens were associated with an increase in breast cancer risk, whereas higher SHBG was inversely associated with risk. The strength of the evidence quality ranged from low to high for each hormone. Dose–response relationships between sex steroid hormone concentrations and breast cancer risk were most notable for post-menopausal women. These data support the plausibility of a role for sex steroid hormones in mediating the causal relationship between physical activity and the risk of breast cancer. See related reviews by Lynch et al., p. 11 and Swain et al., p. 1

    The Potato Nucleotide-Binding Leucine-Rich Repeat (NLR) Immune Receptor Rx1 is a Pathogen Dependent DNA-Deforming Protein

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    Plant NLR proteins enable cells to respond to pathogen attack. Several NLRs act in the nucleus, however, conserved nuclear targets that support their role in immunity are unknown. Previously we noted a structural homology between the NB domain of NLRs and DNA replication origin-binding Cdc6/Orc1 proteins. Here we show that the NB-ARC domain of the Rx1 NLR of potato binds nucleic acids. Rx1 induces ATP-dependent bending and melting of DNA in vitro dependent upon a functional P-loop. In situ full-length Rx1 binds nuclear DNA following activation by its cognate pathogen-derived effector protein, the coat protein of potato virus X. In line with its obligatory nucleocytoplasmic distribution, DNA-binding was only observed when Rx1 was allowed to freely translocate between both compartments and was activated in the cytoplasm. Immune activation induced by an unrelated NLR-effector pair did not trigger a Rx1-DNA interaction. DNA-binding is therefore not merely a consequence of immune activation. These data establish a role for DNA distortion in Rx1 immune signalling and defines DNA as a molecular target of an activated NLR

    Robotic milking technologies and renegotiating situated ethical relationships on UK dairy farms

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    Robotic or automatic milking systems (AMS) are novel technologies that take over the labor of dairy farming and reduce the need for human-animal interactions. Because robotic milking involves the replacement of 'conventional' twice-a-day milking managed by people with a system that supposedly allows cows the freedom to be milked automatically whenever they choose, some claim robotic milking has health and welfare benefits for cows, increases productivity, and has lifestyle advantages for dairy farmers. This paper examines how established ethical relations on dairy farms are unsettled by the intervention of a radically different technology such as AMS. The renegotiation of ethical relationships is thus an important dimension of how the actors involved are re-assembled around a new technology. The paper draws on in-depth research on UK dairy farms comparing those using conventional milking technologies with those using AMS. We explore the situated ethical relations that are negotiated in practice, focusing on the contingent and complex nature of human-animal-technology interactions. We show that ethical relations are situated and emergent, and that as the identities, roles, and subjectivities of humans and animals are unsettled through the intervention of a new technology, the ethical relations also shift. © 2013 Springer Science+Business Media Dordrecht

    The High Velocity Gas toward Messier 5: Tracing Feedback Flows in the Inner Galaxy

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    We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS E140M) observations of the post-asymptotic giant branch star ZNG 1 in the globular cluster Messier 5 (l=3.9, b=+47.7; d=7.5 kpc, z=+5.3 kpc). High velocity absorption is seen in C IV, Si IV, O VI, and lower ionization species at LSR velocities of -140 and -110 km/s. We conclude that this gas is not circumstellar on the basis of photoionization models and path length arguments. Thus, the high velocity gas along the ZNG 1 sight line is the first evidence that highly-ionized HVCs can be found near the Galactic disk. We measure the metallicity of these HVCs to be [O/H]=+0.22\pm0.10, the highest of any known HVC. Given the clouds' metallicity and distance constraints, we conclude that these HVCs have a Galactic origin. This sight line probes gas toward the inner Galaxy, and we discuss the possibility that these HVCs may be related to a Galactic nuclear wind or Galactic fountain circulation in the inner regions of the Milky Way.Comment: 23 pages, 11 figures, 7 table

    Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star

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    We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060^{\rm + 0.0000022 }_ days a mildly metal-poor solar-type star of magnitude V = 11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass M_{\rm p} = 0.503^_ MJM_{\rm J} and radius R_{\rm p} = 1.224^_ RJR_{\rm J}, resulting in a density ρp=0.27±0.05\rho_{\rm p} = 0.27 \pm 0.05 ρJ\rho_{\rm J}. The mass and radius for the host star are M_\ast = 0.88^_ MM_\odot and R_\ast = 0.870^_ RR_\odot. The non-zero orbital eccentricity e = 0.054^{\rm +0.018}_ that we measure suggests that the planet underwent a massive tidal heating ~1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis \beta = 11^_ deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk
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