1,874 research outputs found
OT 060420: A Seemingly Optical Transient Recorded by All-Sky Cameras
We report on a ~5th magnitude flash detected for approximately 10 minutes by
two CONCAM all-sky cameras located in Cerro Pachon - Chile and La Palma -
Spain. A third all-sky camera, located in Cerro Paranal - Chile did not detect
the flash, and therefore the authors of this paper suggest that the flash was a
series of cosmic-ray hits, meteors, or satellite glints. Another proposed
hypothesis is that the flash was an astronomical transient with variable
luminosity. In this paper we discuss bright optical transient detection using
fish-eye all-sky monitors, analyze the apparently false-positive optical
transient, and propose possible causes to false optical transient detection in
all-sky cameras.Comment: 7 figures, 3 tables, accepted PAS
Influenza and pneumococcal vaccination in Australian adults: A systematic review of coverage and factors associated with uptake
© 2016 The Author(s). Background: In the absence of an adult vaccination register, coverage estimates for influenza and pneumococcal vaccination come from surveys and other data sources. Methods: Systematic review and meta-analysis of studies examining vaccination coverage in Australian adults from 1990 to 2015, focusing on groups funded under the National Immunisation Program, and intervals prior to and following the introduction of universal funding. Results: Twenty-two studies met the inclusion criteria; 18 used self-report to determine vaccination status. There were 130 unique estimates of coverage extracted. Among adults aged â„65y, during the period of universal funding (1999-onwards), the summary estimate of annual influenza vaccination coverage from 27 point estimates was 74.8 % (95 % CI 73.4-76.2 %; range 63.9-82.4 %); prior to this period (1992-1998) from 10 point estimates it was 61.3 % (95 % CI 58.0-64.6 %; range 44.3-71.3 %). For the period of universal funding for pneumococcal vaccination (2005-onwards) the summary estimate for coverage was 56.0 % (95 % CI 53.2-58.8 %; range 51.2-72.8 %, 10 point estimates); prior to 2005 it was 35.4 % (95 % CI 18.8-52.0 %; range 15.4-45.2 %). Coverage for both vaccines was significantly higher following the introduction of universal funding. Influenza vaccination coverage in those aged 18-65 years with a medical indication was lower but data were not combined. Seven studies reported on Aboriginal Australians with three studies reporting five coverage estimates for influenza vaccination in adults â„65 years (range 71 % - 89 %). Conclusions: Adult influenza and pneumococcal vaccination coverage has increased since the introduction of universal funding, but remains sub-optimal, with pneumococcal coverage lower than influenza. Implications: This review highlights the need for more coverage data overall and in high risk groups, to support public health programs to improve coverage
Optimisation of energetic and reproductive gains explains behavioural responses to environmental variation across seasons and years
Animals switch between inactive and active states, simultaneously impacting their energy intake, energy expenditure and predation risk, and collectively defining how they engage with environmental variation and trophic interactions. We assess daily activity responses to longâterm variation in temperature, resources and mating opportunities to examine whether individuals choose to be active or inactive according to an optimisation of the relative energetic and reproductive gains each state offers. We show that this simplified behavioural decision approach predicts most activity variation (R2Â =Â 0.83) expressed by freeâranging red squirrels over 4Â years, as quantified through accelerometer recordings (489 deployments; 5066 squirrelâdays). Recognising activity as a determinant of energetic status, the predictability of activity variation aggregated at a daily scale, and the clear signal that behaviour is environmentally forced through optimisation of gain, provides an integrated approach to examine behavioural variation as an intermediary between environmental variation and energetic, lifeâhistory and ecological outcomes.By assessing daily activity responses to longâterm variation in temperature, resources, and mating opportunities, we examine whether individuals choose to be active or inactive according to an optimization of energetic and reproductive gains. This simplified behavioural decision approach predicts most daily activity variation (R2Â =Â 0.83) expressed by freeâranging red squirrels over four years, as quantified through accelerometer recordings. Here we provide an integrated approach to examine behavioural variation as an intermediary between environmental variation and energetic, lifeâhistory, and ecological outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154889/1/ele13494_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154889/2/ele13494.pd
Design and Synthesis of Broad Spectrum Trypanosomatid Selective Inhibitors
Neglected
tropical diseases caused by parasitic infections are an ongoing and
increasing concern that have a devastating effect on the developing
world due to their burden on human and animal health. In this work,
we detail the preparation of a focused library of substituted-tetrahydropyran
derivatives and their evaluation as selective chemical tools for trypanosomatid
inhibition and the follow-on development of photoaffinity probes capable
of labeling target protein(s) <i>in vitro</i>. Several of
these functionalized compounds maintain low micromolar activity against <i>Trypanosoma brucei</i>, <i>Trypanosoma cruzi</i>, <i>Leishmania major</i>, and <i>Leishmania donovani</i>. In addition, we demonstrate the utility of the photoaffinity probes
for target identification through preliminary cellular localization
studies
Photometric Properties of Kiso Ultraviolet-Excess Galaxies in the Lynx-Ursa Major Region
We have performed a systematic study of several regions in the sky where the
number of galaxies exhibiting star formation (SF) activity is greater than
average. We used Kiso ultraviolet-excess galaxies (KUGs) as our SF-enhanced
sample. By statistically comparing the KUG and non-KUG distributions, we
discovered four KUG-rich regions with a size of . One of these regions corresponds spatially to a filament of length
Mpc in the Lynx-Ursa Major region (). We call this ``the Lynx-Ursa
Major (LUM) filament''. We obtained surface photometry of 11 of
the KUGs in the LUM filament and used these to investigate the integrated
colors, distribution of SF regions, morphologies, and local environments. We
found that these KUGs consist of distorted spiral galaxies and compact galaxies
with blue colors. Their star formation occurs in the entire disk, and is not
confined to just the central regions. The colors of the SF regions imply that
active star formation in the spiral galaxies occurred yr ago,
while that of the compact objects occurred yr ago. Though the
photometric characteristics of these KUGs are similar to those of interacting
galaxies or mergers, most of these KUGs do not show direct evidence of merger
processes.Comment: 39 pages LaTeX, using aasms4.sty, 20 figures, ApJS accepted. The
Title of the previous one was truncated by the author's mistake, and is
corrected. Main body of the paper is unchange
Towards A Census of Earth-mass Exo-planets with Gravitational Microlensing
Thirteen exo-planets have been discovered using the gravitational
microlensing technique (out of which 7 have been published). These planets
already demonstrate that super-Earths (with mass up to ~10 Earth masses) beyond
the snow line are common and multiple planet systems are not rare. In this
White Paper we introduce the basic concepts of the gravitational microlensing
technique, summarise the current mode of discovery and outline future steps
towards a complete census of planets including Earth-mass planets. In the
near-term (over the next 5 years) we advocate a strategy of automated follow-up
with existing and upgraded telescopes which will significantly increase the
current planet detection efficiency. In the medium 5-10 year term, we envision
an international network of wide-field 2m class telescopes to discover
Earth-mass and free-floating exo-planets. In the long (10-15 year) term, we
strongly advocate a space microlensing telescope which, when combined with
Kepler, will provide a complete census of planets down to Earth mass at almost
all separations. Such a survey could be undertaken as a science programme on
Euclid, a dark energy probe with a wide-field imager which has been proposed to
ESA's Cosmic Vision Programme.Comment: 10 pages. White Paper submission to the ESA Exo-Planet Roadmap
Advisory Team. See also "Inferring statistics of planet populations by means
of automated microlensing searches" by M. Dominik et al. (arXiv:0808.0004
Silicon enhances the accumulation of diterpenoid phytoalexins in rice: A potential mechanism for blast resistance
Although several reports underscore the importance of silicon (Si) in controlling Magnaporthe grisea on rice, no study has associated this beneficial effect with specific mechanisms of host defense responses against this fungal attack. In this study, however, we provide evidence that higher levels of momilactone phytoalexins were found in leaf extracts from plants inoculated with M. grisea and amended with silicon (Si+) than in leaf extracts from inoculated plants not amended with silicon (Si-) or noninoculated Si+ and Si- plants. On this basis, the more efficient stimulation of the terpenoid pathway in Si+ plants and, consequently, the increase in the levels of momilactones appears to be a factor contributing to enhanced rice resistance to blast. This may explain the lower level of blast severity observed on leaves of Si+ plants at 96 h after inoculation with M. grisea. The results of this study strongly suggest that Si plays an active role in the resistance of rice to blast rather than the formation of a physical barrier to penetration by M. grisea
Spectral Irradiance Calibration in the Infrared. XIII. "Supertemplates" and On-Orbit Calibrators for SIRTF's Infrared Array Camera (IRAC)
We describe the technique used to develop on-orbit calibrators for IRAC and
validate the method for either K0-M0III or A0-A5V stars. For SIRTF, the
approach uses all available optical, NIR, and MIR photometry, and yields
absolute spectra from UV to MIR. One set of stars is from Landolt's network of
optical standards, the other from Carter-Meadows IR standards. Traceability to
the Cohen-Walker- Witteborn framework of absolute photometry and spectra is
assured. The method is based on using either "supertemplates" to represent the
intrinsic shapes of the spectra of K0-M0IIIs from 1150A to 35 um, or Kurucz
synthetic spectra for A0-5V stars. Each supertemplate/model is reddened
according to a star's extinction and normalized by characterized optical
photometry. This paper tests our ability to predict NIR (JHK) magnitudes from
supertemplates or models constrained by Hippa- rcos/Tycho or precision
ground-based optical data. We offer absolute calibrated spectra of 33 optical
standards to demonstrate the viability of this technique for a set of IR
calibrators 100-1000 times fainter than we have previously publ- ished. We
calculate the absolute uncertainties associated with predicting IRAC mags for
the faintest cool giant and hot dwarf in this new set of calibrators.Comment: 53 pages, Latex, AASTEX5 macro
Characterising the original anti-C5 function-blocking antibody, BB5.1, for species specificity, mode of action and interactions with C5
The implication of complement in multiple diseases over the last twenty years has fuelled interest in developing antiâcomplement drugs. To date, the focus has been on C5; blocking cleavage of C5 prevents formation of two proâinflammatory activities, C5a anaphylatoxin and membrane attack complex. The concept of C5 blockade to inhibit inflammation dates back thirty years to the description of BB5.1, an antiâC5 blocking monoclonal antibody raised in C5âdeficient mice. This antibody proved an invaluable tool to demonstrate complement involvement in mouse disease models and catalysed enthusiasm for antiâcomplement drug development, culminating in the antiâhuman C5 monoclonal antibody ecuizumab, the most successful antiâcomplement drug to date, already in the clinic for several rare diseases. Despite its key role in providing proofâofâconcept for C5 blockade, the mechanism of BB5.1 inhibition remains poorly understood. Here we characterised BB5.1 crossâspecies inhibition, C5 binding affinity and chain specificity. BB5.1 efficiently inhibited C5 in mouse serum but not in human or other rodent sera; it prevented C5 cleavage and C5a generation. BB5.1 bound the C5 αâchain with high affinity and slow offârate. BB5.1 complementarity determining regions were obtained and docking algorithms used to predict the likely binding interface on mouse C5
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