2,294 research outputs found
Form removal aspects on the waviness parameters for steel sheet in automotive applications : fourier filtering versus polynomial regression
Premium car makers attach great importance to the visual appearance of the painted car skin as an indication of product quality. The âorange peelâ phenomenon constitutes a major problem here. It is not only depending on the paintâs chemical composition and application method, but also on possible waviness components in the sheet substrate. Therefore one is searching hard for a valuable waviness parameter to quantify the substrateâs fitness for purpose. A technically emerging problem is how to remove the form from the measured signal, which is indeed not significant to the orange peel phenomenon. This paper will compare two commonly used approaches: i.e. Fourier filtering versus polynomial regression and will reveal and quantify some common aspects in terms of wavelengths
Dusty star forming galaxies at high redshift
The global star formation rate in high redshift galaxies, based on optical
surveys, shows a strong peak at a redshift of z=1.5, which implies that we have
already seen most of the formation. High redshift galaxies may, however, emit
most of their energy at submillimeter wavelengths if they contain substantial
amounts of dust. The dust would absorb the starlight and reradiate it as
far-infrared light, which would be redshifted to the submillimeter range. Here
we report a deep survey of two blank regions of sky performed at submillimeter
wavelengths (450 and 850-micron). If the sources we detect in the 850-micron
band are powered by star formation, then each must be converting more than 100
solar masses of gas per year into stars, which is larger than the maximum star
formation rates inferred for most optically-selected galaxies. The total amount
of high redshift star formation is essentially fixed by the level of background
light, but where the peak occurs in redshift for the submillimeter is not yet
established. However, the background light contribution from only the sources
detected at 850-micron is already comparable to that from the
optically-selected sources. Establishing the main epoch of star formation will
therefore require a combination of optical and submillimeter studies.Comment: 10 pages + 2 Postscript figures, under embargo at Natur
Vigorous star formation hidden by dust in a galaxy at
Near-infrared surveys have revealed a substantial population of enigmatic
faint galaxies with extremely red optical-to-near-infrared colours and with a
sky surface density comparable to that of faint quasars. There are two
scenarios for these extreme colours: (i) these distant galaxies have formed
virtually all their stars at very high redshifts and, due to the absence of
recently formed stars, the colours are extremely red and (ii) these distant
galaxies contain large amounts of dust, severely reddening the rest-frame
UV--optical spectrum. HR10 () is considered the archetype of the
extremely red galaxies. Here we report the detection of the continuum emission
from HR10 at 850m and at 1250m, demonstrating that HR10 is a very
dusty galaxy undergoing a major episode of star formation. Our result provides
a clear example of a high-redshift galaxy where the star formation rate
inferred from the ultraviolet luminosity would be underestimated by a factor up
to 1000, and shows that great caution should be used to infer the global star
formation history of the Universe from optical observations only.Comment: 12 pages, 1 figure, Nature, in press (30 April 1998
The Hip Fracture Surgery in Elderly Patients (HIPELD) study: protocol for a randomized, multicenter controlled trial evaluating the effect of xenon on postoperative delirium in older patients undergoing hip fracture surgery
BackgroundStrategies to protect the brain from postoperative delirium (POD) after hip fracture are urgently needed. The development of delirium often is associated with the loss of independence, poor functional recovery, and increased morbidity, as well as increases in length of hospital stay, discharges to nursing facilities, and healthcare costs. We hypothesize that xenon may reduce the burden of POD, (i) by avoiding the need to provide anesthesia with a drug that targets the Îł-amino-butyric acid (GABA)A receptor and (ii) through beneficial anesthetic and organ-protective effects.Methods and designAn international, multicenter, phase 2, prospective, randomized, blinded, parallel group and controlled trial to evaluate the incidence of POD, diagnosed with the Confusion Assessment Method (CAM), in older patients undergoing hip fracture surgery under general anesthesia with xenon or sevoflurane, for a period of 4 days post surgery (primary outcome) is planned. Secondary objectives are to compare the incidence of POD between xenon and sevoflurane, to evaluate the incidence of POD from day 5 post surgery until discharge from hospital, to determine the time to first POD diagnosis, to evaluate the duration of POD, to evaluate the evolution of the physiological status of the patients in the postoperative period, to evaluate the recovery parameters, to collect preliminary data to evaluate the economical impact of POD in the postoperative period and to collect safety data. Patients are eligible if they are older aged (â„ 75 years) and assigned to a planned hip fracture surgery within 48 h after the hip fracture. Furthermore, patients need to be willing and able to complete the requirements of this study including the signature of the written informed consent. A total of 256 randomized patients in the 10 participating centers will be recruited, that is, 128 randomized patients in each of the 2 study groups (receiving either xenon or sevoflurane).Trial registrationEudraCT Identifier: 2009-017153-35; ClinicalTrials.gov Identifier: NCT0119927
Phenoloxidase activity acts as a mosquito innate immune response against infection with semliki forest virus
Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest virus (SFV) (Togaviridae; Alphavirus). Production of recombinant SFV expressing the PO cascade inhibitor Egf1.0 blocked PO activity in U4.4 cell- conditioned medium, which resulted in enhanced spread of SFV. Infection of adult female Aedes aegypti by feeding mosquitoes a bloodmeal containing Egf1.0-expressing SFV increased virus replication and mosquito mortality. Collectively, these results suggest the PO cascade of mosquitoes plays an important role in immune defence against arboviruses
Antibody responses induced by SHIV infection are more focused than those induced by soluble native HIV-1 envelope trimers in non-human primates
The development of an effective human immunodeficiency virus (HIV-1) vaccine is a high
global health priority. Soluble native-like HIV-1 envelope glycoprotein trimers (Env), including those based on the SOSIP design, have shown promise as vaccine candidates by inducing neutralizing antibody responses against the autologous virus in animal models.
However, to overcome HIV-1âs extreme diversity a vaccine needs to induce broadly neutralizing antibodies (bNAbs). Such bNAbs can protect non-human primates (NHPs) and
humans from infection. The prototypic BG505 SOSIP.664 immunogen is based on the
BG505 env sequence isolated from an HIV-1-infected infant from Kenya who developed a
bNAb response. Studying bNAb development during natural HIV-1 infection can inform vaccine design, however, it is unclear to what extent vaccine-induced antibody responses to
Env are comparable to those induced by natural infection. Here, we compared Env antibody
responses in BG505 SOSIP-immunized NHPs with those in BG505 SHIV-infected NHPs,
by analyzing monoclonal antibodies (mAbs). We observed three major differences between
BG505 SOSIP immunization and BG505 SHIV infection. First, SHIV infection resulted in
more clonal expansion and less antibody diversity compared to SOSIP immunization, likely because of higher and/or prolonged antigenic stimulation and increased antigen diversity
during infection. Second, while we retrieved comparatively fewer neutralizing mAbs (NAbs)
from SOSIP-immunized animals, these NAbs targeted more diverse epitopes compared to
NAbs from SHIV-infected animals. However, none of the NAbs, either elicited by vaccination
or infection, showed any breadth. Finally, SOSIP immunization elicited antibodies against
the base of the trimer, while infection did not, consistent with the base being placed onto the
virus membrane in the latter setting. Together these data provide new insights into the antibody response against BG505 Env during infection and immunization and limitations that
need to be overcome to induce better responses after vaccination
The GaiaâESO Survey: dynamical models of flattened, rotating globular clusters
We present a family of self-consistent axisymmetric rotating globular cluster models which are fitted to spectroscopic data for NGC 362, NGC 1851, NGC 2808, NGC 4372, NGC 5927 and NGC 6752 to provide constraints on their physical and kinematic properties, including their rotation signals. They are constructed by flattening Modified Plummer profiles, which have the same asymptotic behaviour as classical Plummer models, but can provide better fits to young clusters due to a slower turnover in the density profile. The models are in dynamical equilibrium as they depend solely on the action variables. We employ a fully Bayesian scheme to investigate the uncertainty in our model parameters (including mass-to-light ratios and inclination angles) and evaluate the Bayesian evidence ratio for rotating to non-rotating models. We find convincing levels of rotation only in NGC 2808. In the other clusters, there is just a hint of rotation (in particular, NGC 4372 and NGC 5927), as the data quality does not allow us to draw strong conclusions. Where rotation is present, we find that it is confined to the central regions, within radii of R †2rh. As part of this work, we have developed a novel q-Gaussian basis expansion of the line-of-sight velocity distributions, from which general models can be constructed via interpolation on the basis coefficients.This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and Ministero dellâ Istruzione, dellâ UniversitĂ â e della Ricerca (MIUR) in the form of the grant âPremiale VLT 2012â
Genome-wide association study of male sexual orientation
Family and twin studies suggest that genes play a role in male sexual orientation. We conducted a genome-wide association study (GWAS) of male sexual orientation on a primarily European ancestry sample of 1,077 homosexual men and 1,231 heterosexual men using Affymetrix single nucleotide polymorphism (SNP) arrays. We identified several SNPs with p < 10 -5 , including regions of multiple supporting SNPs on chromosomes 13 (minimum p = 7.5 Ă 10 -7 ) and 14 (p = 4.7 Ă 10 -7 ). The genes nearest to these peaks have functions plausibly relevant to the development of sexual orientation. On chromosome 13, SLITRK6 is a neurodevelopmental gene mostly expressed in the diencephalon, which contains a region previously reported as differing in size in men by sexual orientation. On chromosome 14, TSHR genetic variants in intron 1 could conceivably help explain past findings relating familial atypical thyroid function and male homosexuality. Furthermore, skewed X chromosome inactivation has been found in the thyroid condition, Graves' disease, as well as in mothers of homosexual men. On pericentromeric chromosome 8 within our previously reported linkage peak, we found support (p = 4.1 Ă 10 -3 ) for a SNP association previously reported (rs77013977, p = 7.1 Ă 10 -8 ), with the combined analysis yielding p = 6.7 Ă 10 -9 , i.e., a genome-wide significant association
The Pioneer Anomaly
Radio-metric Doppler tracking data received from the Pioneer 10 and 11
spacecraft from heliocentric distances of 20-70 AU has consistently indicated
the presence of a small, anomalous, blue-shifted frequency drift uniformly
changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was
interpreted as a constant sunward deceleration of each particular spacecraft at
the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of
the Newton's gravitational inverse-square law has become known as the Pioneer
anomaly; the nature of this anomaly remains unexplained. In this review, we
summarize the current knowledge of the physical properties of the anomaly and
the conditions that led to its detection and characterization. We review
various mechanisms proposed to explain the anomaly and discuss the current
state of efforts to determine its nature. A comprehensive new investigation of
the anomalous behavior of the two Pioneers has begun recently. The new efforts
rely on the much-extended set of radio-metric Doppler data for both spacecraft
in conjunction with the newly available complete record of their telemetry
files and a large archive of original project documentation. As the new study
is yet to report its findings, this review provides the necessary background
for the new results to appear in the near future. In particular, we provide a
significant amount of information on the design, operations and behavior of the
two Pioneers during their entire missions, including descriptions of various
data formats and techniques used for their navigation and radio-science data
analysis. As most of this information was recovered relatively recently, it was
not used in the previous studies of the Pioneer anomaly, but it is critical for
the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living
Reviews in Relativit
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