745 research outputs found
Measurement-based Run-to-run Optimization of a Batch Reaction-distillation System
Measurement-based optimization schemes have been developed to deal with uncertainty and process variations. One of the methods therein, labeled NCO tracking, relies on appropriate parameterization of the input profiles and adjusts the corresponding input parameters using measurements so as to satisfy the necessary conditions of optimality (NCO). The applicability of NCO-tracking schemes has been demonstrated on several academic-size examples. The goal of this paper is to show that it can be applied with similar ease to more complex real-life systems. Run-to-run optimization of a batch reaction-separation system with propylene glycol is used for illustration
Impact of the 3D source geometry on time-delay measurements of lensed type-Ia Supernovae
It has recently been proposed that gravitationally lensed type-Ia supernovae
can provide microlensing-free time-delay measurements provided that the
measurement is taken during the achromatic expansion phase of the explosion and
that color light curves are used rather than single-band light curves. If
verified, this would provide both precise and accurate time-delay measurements,
making lensed type-Ia supernovae a new golden standard for time-delay
cosmography. However, the 3D geometry of the expanding shell can introduce an
additional bias that has not yet been fully explored. In this work, we present
and discuss the impact of this effect on time-delay cosmography with lensed
supernovae and find that on average it leads to a bias of a few tenths of a day
for individual lensed systems. This is negligible in view of the cosmological
time delays predicted for typical lensed type-Ia supernovae but not for the
specific case of the recently discovered type-Ia supernova iPTF16geu, whose
time delays are expected to be smaller than a day.Comment: 7 pages, 4 figures, published in A&
Evasins: Therapeutic Potential of a New Family of Chemokine-Binding Proteins from Ticks
Blood sucking parasites such as ticks remain attached to their hosts for relatively long periods of time in order to obtain their blood meal without eliciting an immune response. One mechanism used to avoid rejection is the inhibition of the recruitment of immune cells, which can be achieved by a class of chemokine binding proteins (CKBPs) known as Evasins. We have identified three distinct Evasins produced by the salivary glands of the common brown dog tick, Rhipicephalus sanguineus. They display different selectivities for chemokines, the first two identified show a narrow selectivity profile, whilst the third has a broader binding spectrum. The Evasins showed efficacy in several animal models of inflammatory disease. Here we will discuss the potential of their development for therapeutic use, addressing both the advantages and disadvantages that this entails
The Hubble Constant determined through an inverse distance ladder including quasar time delays and Type Ia supernovae
Context. The precise determination of the present-day expansion rate of the
Universe, expressed through the Hubble constant , is one of the most
pressing challenges in modern cosmology. Assuming flat CDM,
inference at high redshift using cosmic-microwave-background data from Planck
disagrees at the 4.4 level with measurements based on the local
distance ladder made up of parallaxes, Cepheids and Type Ia supernovae (SNe
Ia), often referred to as "Hubble tension". Independent,
cosmological-model-insensitive ways to infer are of critical importance.
Aims. We apply an inverse-distance-ladder approach, combining strong-lensing
time-delay-distance measurements with SN Ia data. By themselves, SNe Ia are
merely good relative distance indicators, but by anchoring them to strong
gravitational lenses one can obtain an measurement that is relatively
insensitive to other cosmological parameters. Methods. A cosmological parameter
estimate is performed for different cosmological background models, both for
strong-lensing data alone and for the combined lensing + SNe Ia data sets.
Results. The cosmological-model dependence of strong-lensing measurements
is significantly mitigated through the inverse distance ladder. In combination
with SN Ia data, the inferred consistently lies around 73-74 km s
Mpc, regardless of the assumed cosmological background model. Our
results agree nicely with those from the local distance ladder, but there is a
>2 tension with Planck results, and a ~1.5 discrepancy with
results from an inverse distance ladder including Planck, Baryon Acoustic
Oscillations and SNe Ia. Future strong-lensing distance measurements will
reduce the uncertainties in from our inverse distance ladder.Comment: 5 pages, 3 figures, A&A letters accepted versio
Healthcare professionals' sources of knowledge of complementary medicine in an academic center.
Complementary medicine (CM) is utilized in a growing number of academic centers despite the debate concerning its value, risks and benefits. Healthcare professionals often feel uncomfortable discussing CM with patients, and little is known about their sources of knowledge in the field of CM.
To assess healthcare professionals' sources of knowledge and attitude toward CM in an academic hospital.
The cross-sectional web-based survey took place from October to December 2013. A total of 4,925 healthcare professionals working at Lausanne University Hospital, Switzerland, were invited to answer the questionnaire.
Factors influencing healthcare professionals' opinion toward CM, knowledge and communication about CM.
The questionnaire was answered by 1,247 healthcare professionals. The three key factors influencing professionals' opinion toward CM were personal experience, clinical experience and evidence demonstrating the physiological mechanism of CM. Personal experience was more associated with nurses' and midwives' opinion compared to physicians' (80.8% vs 57.1%, OR = 3.08, [95% CI: 2.35-4.05], P<0.001 and 85.3% vs 57.1%, OR = 3.83, [95% CI: 1.95-7.53], P<0.001, respectively) as well as with professionals trained in CM compared to non-trained professionals (86.0% vs 73.2%, OR = 2.60, [95% CI: 1.92-3.53], P<0.001). Physicians relied more on randomized controlled clinical trials compared to nurses (81.3% vs 62.9%, OR = 0.43, [95% CI: 0.33-0.57], P<0.001). A majority of the respondents (82.5%) agreed that they lacked knowledge about CM and 65.0% noted that it was the patient who initially started the discussion about CM.
Different professionals used different strategies to forge opinions regarding CM: physicians relied more on scientific evidence, while nurses and midwives were more influenced by personal experience. Regardless of preferred information source, most respondents did not feel prepared to address patient questions regarding CM. Enhancing interprofessional education opportunities is an important strategy to help providers become empowered to discuss CM with patients. This in turn will help patients making informed decisions in their healthcare
Effect of Peculiar Motion in Weak Lensing
We study the effect of peculiar motion in weak gravitational lensing. We
derive a fully relativistic formula for the cosmic shear and the convergence in
a perturbed Friedmann Universe. We find a new contribution related to galaxies
peculiar velocity. This contribution does not affect cosmic shear in a
measurable way, since it is of second order in the velocity. However, its
effect on the convergence (and consequently on the magnification, which is a
measurable quantity) is important, especially for redshifts z < 1. As a
consequence, peculiar motion modifies also the relation between the shear and
the convergence.Comment: 11 pages, 7 figures; v2: discussion on the reduced shear added (5.C),
additional references, version accepted in PRD; v3: mistakes corrected in
eqs. (26), (31), (33) and (44); results unchange
Cosmic shear bispectrum from second-order perturbations in General Relativity
Future lensing surveys will be nearly full-sky and reach an unprecedented
depth, probing scales closer and closer to the Hubble radius. This motivates
the study of the cosmic shear beyond the small-angle approximation and
including general relativistic corrections that are usually suppressed on
sub-Hubble scales. The complete expression of the reduced cosmic shear at
second order including all relativistic effects was derived in [1]. In the
present paper we compute the resulting cosmic shear bispectrum when all these
effects are properly taken into account and we compare it to primordial
non-Gaussianity of the local type. The new general relativistic effects are
generically smaller than the standard non-linear couplings. However, their
relative importance increases at small multipoles and for small redshifts of
the sources. The dominant effect among these non standard corrections is due to
the inhomogeneity of the source redshift. In the squeezed limit, its amplitude
can become of the order of the standard couplings when the redshift of the
sources is below 0.5. Moreover, while the standard non-linear couplings depend
on the angle between the short and long mode, the relativistic corrections do
not and overlap almost totally with local type non-Gaussianity. We find that
they can contaminate the search for a primordial local signal by f_NL>10.Comment: 41 pages, 8 figures, some modifications in the analysis of the
redshift dependence in section 5, 1 new figur
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Acrylic vessel cleaning tests
The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory
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