636 research outputs found
Electron and proton heating by solar wind turbulence
Previous formulations of heating and transport associated with strong
magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate
internal energy equations for electrons and protons. Electron heat conduction
is included. Energy is supplied by turbulent heating that affects both
electrons and protons, and is exchanged between them via collisions. Comparison
to available Ulysses data shows that a reasonable accounting for the data is
provided when (i) the energy exchange timescale is very long and (ii) the
deposition of heat due to turbulence is divided, with 60% going to proton
heating and 40% into electron heating. Heat conduction, determined here by an
empirical fit, plays a major role in describing the electron data
RCS2 J232727.6-020437: An Efficient Cosmic Telescope at
We present a detailed gravitational lens model of the galaxy cluster RCS2
J232727.6-020437. Due to cosmological dimming of cluster members and ICL, its
high redshift () makes it ideal for studying background galaxies.
Using new ACS and WFC3/IR HST data, we identify 16 multiple images. From
MOSFIRE follow up, we identify a strong emission line in the spectrum of one
multiple image, likely confirming the redshift of that system to .
With a highly magnified () source plane area of
arcmin at , RCS2 J232727.6-020437 has a lensing efficiency comparable
to the Hubble Frontier Fields clusters. We discover four highly magnified
candidate Lyman-break galaxies behind the cluster, one of which may be
multiply-imaged. Correcting for magnification, we find that all four galaxies
are fainter than . One candidate is detected at in
both Spitzer/IRAC [3.6] and [4.5] channels. A spectroscopic follow-up with
MOSFIRE does not result in the detection of the Lyman-alpha emission line from
any of the four candidates. From the MOSFIRE spectra we place median upper
limits on the Lyman-alpha flux of ().Comment: 14 pages, 9 figures, submitted to ApJ on 3/06/201
Spitzer UltRa Faint SUrvey Program (SURFS UP). II. IRAC-Detected Lyman-Break Galaxies at 6 < z < 10 Behind Strong-Lensing Clusters
We study the stellar population properties of the IRAC-detected galaxy candidates from the Spitzer UltRa Faint SUrvey Program
(SURFS UP). Using the Lyman Break selection technique, we find a total of 16
new galaxy candidates at with in at
least one of the IRAC m and m bands. According to the best mass
models available for the surveyed galaxy clusters, these IRAC-detected galaxy
candidates are magnified by factors of --. We find that the
IRAC-detected sample is likely not a homogeneous
galaxy population: some are relatively massive (stellar mass as high as ) and evolved (age Myr) galaxies, while
others are less massive () and very
young ( Myr) galaxies with strong nebular emission lines that boost
their rest-frame optical fluxes. We identify two Ly emitters in our
sample from the Keck DEIMOS spectra, one at (in
RXJ1347) and one at (in MACS0454). We show that IRAC
color, when combined with photometric redshift, can be used to
identify galaxies likely with strong nebular emission lines within certain
redshift windows.Comment: ApJ in pres
Cellular and humoral immune responses and protection against schistosomes induced by a radiation-attenuated vaccine in chimpanzees
The radiation-attenuated Schistosoma mansoni vaccine is highly effective in rodents and primates but has never been tested in humans, primarily for safety reasons. To strengthen its status as a paradigm for a human recombinant antigen vaccine, we have undertaken a small-scale vaccination and challenge experiment in chimpanzees (Pan troglodytes). Immunological, clinical, and parasitological parameters were measured in three animals after multiple vaccinations, together with three controls, during the acute and chronic stages of challenge infection up to chemotherapeutic cure. Vaccination induced a strong in vitro proliferative response and early gamma interferon production, but type 2 cytokines were dominant by the time of challenge. The controls showed little response to challenge infection before the acute stage of the disease, initiated by egg deposition. In contrast, the responses of vaccinated animals were muted throughout the challenge period. Vaccination also induced parasite-specific immunoglobulin M (IgM) and IgG, which reached high levels at the time of challenge, while in control animals levels did not rise markedly before egg deposition. The protective effects of vaccination were manifested as an amelioration of acute disease and overall morbidity, revealed by differences in gamma-glutamyl transferase level, leukocytosis, eosinophilia, and hematocrit. Moreover, vaccinated chimpanzees had a 46% lower level of circulating cathodic antigen and a 38% reduction in fecal egg output, compared to controls, during the chronic phase of infection
Constructing living buildings: a review of relevant technologies for a novel application of biohybrid robotics
Biohybrid robotics takes an engineering approach to the expansion and exploitation of biological behaviours for application to automated tasks. Here, we identify the construction of living buildings and infrastructure as a high-potential application domain for biohybrid robotics, and review technological advances relevant to its future development. Construction, civil infrastructure maintenance and building occupancy in the last decades have comprised a major portion of economic production, energy consumption and carbon emissions. Integrating biological organisms into automated construction tasks and permanent building components therefore has high potential for impact. Live materials can provide several advantages over standard synthetic construction materials, including self-repair of damage, increase rather than degradation of structural performance over time, resilience to corrosive environments, support of biodiversity, and mitigation of urban heat islands. Here, we review relevant technologies, which are currently disparate. They span robotics, self-organizing systems, artificial life, construction automation, structural engineering, architecture, bioengineering, biomaterials, and molecular and cellular biology. In these disciplines, developments relevant to biohybrid construction and living buildings are in the early stages, and typically are not exchanged between disciplines. We, therefore, consider this review useful to the future development of biohybrid engineering for this highly interdisciplinary application.publishe
The effects of low-intensity narrow-band blue-light treatment compared to bright white-light treatment in sub-syndromal seasonal affective disorder
Randomised trials of 6 % tetrastarch (hydroxyethyl starch 130/0.4 or 0.42) for severe sepsis reporting mortality: systematic review and meta-analysis.
Improving Metabolic Health Through Precision Dietetics in Mice
The incidence of diet-induced metabolic disease has soared over the last half-century, despite national efforts to improve health through universal dietary recommendations. Studies comparing dietary patterns of populations with health outcomes have historically provided the basis for healthy diet recommendations. However, evidence that population-level diet responses are reliable indicators of responses across individuals is lacking. This study investigated how genetic differences influence health responses to several popular diets in mice, which are similar to humans in genetic composition and the propensity to develop metabolic disease, but enable precise genetic and environmental control. We designed four human-comparable mouse diets that are representative of those eaten by historical human populations. Across four genetically distinct inbred mouse strains, we compared the American diet’s impact on metabolic health to three alternative diets (Mediterranean, Japanese, and Maasai/ketogenic). Furthermore, we investigated metabolomic and epigenetic alterations associated with diet response. Health effects of the diets were highly dependent on genetic background, demonstrating that individualized diet strategies improve health outcomes in mice. If similar genetic-dependent diet responses exist in humans, then a personalized, or “precision dietetics,” approach to dietary recommendations may yield better health outcomes than the traditional one-size-fits-all approach
Search for R-parity violating supersymmetry via the LLE couplings lambda_{121}, lambda_{122} or lambda_{133} in ppbar collisions at sqrt(s)=1.96 TeV
A search for gaugino pair production with a trilepton signature in the
framework of R-parity violating supersymmetry via the couplings lambda_121,
lambda_122, or lambda_133 is presented. The data, corresponding to an
integrated luminosity of L~360/pb, were collected from April 2002 to August
2004 with the D0 detector at the Fermilab Tevatron Collider, at a
center-of-mass energy of sqrt(s)=1.96 TeV. This analysis considers final states
with three charged leptons with the flavor combinations eel, mumul, and eetau
(l=e or mu). No evidence for supersymmetry is found and limits at the 95%
confidence level are set on the gaugino pair production cross section and lower
bounds on the masses of the lightest neutralino and chargino are derived in two
supersymmetric models.Comment: 9 pages, 4 figures (fig2 includes 3 subfigures
Search for W' boson production in the W'->tb decay channel
We present a search for the production of a new heavy gauge boson W' that
decays to a top quark and a bottom quark. We have analyzed 230 pb^{-1} of data
collected with the Dzero detector at the Fermilab Tevatron collider at a
center-of-mass energy of 1.96 TeV. No significant excess of events above the
standard model expectation is found in any region of the final state invariant
mass distribution. We set upper limits on the production cross section of W'
bosons times branching ratio to top quarks at the 95% confidence level for
several different W' boson masses. We exclude masses between 200 GeV and 610
GeV for a W' boson with standard-model-like couplings, between 200 GeV and 630
GeV for a W' boson with right-handed couplings that is allowed to decay to both
leptons and quarks, and between 200 GeV and 670 GeV for a W' boson with
right-handed couplings that is only allowed to decay to quarks.Comment: 9 pages, 6 figures, accepted by Phys. Lett.
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