3,941 research outputs found
Properties of compact 250 μm emission and H II regions in M 33 (HERM33ES)
Aims. Within the framework of the HERM33ES key program, using the high resolution and sensitivity of the Herschel photometric
data, we study the compact emission in the Local Group spiral galaxy M33 to investigate the nature of the compact SPIRE emission
sources. We extracted a catalogue of sources at 250 μm in order to investigate the nature of this compact emission. Taking advantage
of the unprecedented Herschel resolution at these wavelengths, we also focus on a more precise study of some striking Hα shells in
the northern part of the galaxy.
Methods. We present a catalogue of 159 compact emission sources in M33 identified by SExtractor in the 250 μm SPIRE band that
is the one that provides the best spatial resolution. We also measured fluxes at 24 μm and Hα for those 159 extracted sources. The
morphological study of the shells also benefits from a multiwavelength approach including Hα, far-ultraviolet from GALEX, and
infrared from both Spitzer IRAC 8 μm and MIPS 24 μm in order to make comparisons.
Results. For the 159 compact sources selected at 250 μm, we find a very strong Pearson correlation coefficient with the MIPS 24 μm
emission (r_(24) = 0.94) and a rather strong correlation with the Hα emission, although with more scatter (r_(Hα) = 0.83). The morphological
study of the Hα shells shows a displacement between far-ultraviolet, Hα, and the SPIRE bands. The cool dust emission from
SPIRE clearly delineates the Hα shell structures.
Conclusions. The very strong link between the 250 μm compact emission and the 24 μm and Hα emissions, by recovering the star formation
rate from standard recipes for H II regions, allows us to provide star formation rate calibrations based on the 250 μm compact
emission alone. The different locations of the Hα and far-ultraviolet emissions with respect to the SPIRE cool dust emission leads to
a dynamical age of a few Myr for the Hα shells and the associated cool dust
V-Shape Liquid Crystal-Based Retromodulator Air to Ground Optical Communications
This paper describes the use of a 2D liquid crystal retro-modulator as a free space, wireless, optical link. The retro-modulator is made up of a retro-reflecting cornercube onto which 2 cascaded V-shape smectics liquid crystal modulators are mounted. The communication link differs with respect to more conventional optical links in not using amplitude (nor frequency) modulation, but instead state-of-polarisation (SOP) modulation known as Polarisation Shift Keying (PolSK). PolSK has the advantage over amplitude modulation, that it is less sensitive to changes in the visibility of the atmosphere, and increases inherently the bandwidth of the link. The implementation of PolSK both in liquid crystal based and in retro-modulated communication are novelties
Properties of compact 250 \mu m emission and HII regions in M33 (HERM33ES)
Within the framework of the HERM33ES Key Project, using the high resolution
and sensitivity of the Herschel photometric data, we study the compact emission
in the Local Group spiral galaxy M33 to investigate the nature of the compact
SPIRE emission sources. We extracted a catalogue of sources at 250um in order
to investigate the nature of this compact emission. Taking advantage of the
unprecedented Herschel resolution at these wavelengths, we also focus on a more
precise study of some striking Halpha shells in the northern part of the
galaxy. We present a catalogue of 159 compact emission sources in M33
identified by SExtractor in the 250um SPIRE band that is the one that provides
the best spatial resolution. We also measured fluxes at 24um and Halpha for
those 159 extracted sources. The morphological study of the shells also
benefits from a multiwavelength approach including Halpha, far-UV from GALEX,
and infrared from both Spitzer IRAC 8um and MIPS 24um in order to make
comparisons. For the 159 compact sources selected at 250um, we find a very
strong Pearson correlation coefficient with the MIPS 24um emission (r24 = 0.94)
and a rather strong correlation with the Halpha emission, although with more
scatter (rHa = 0.83). The morphological study of the Halpha shells shows a
displacement between far-ultraviolet, Halpha, and the SPIRE bands. The cool
dust emission from SPIRE clearly delineates the Halpha shell structures. The
very strong link between the 250um compact emission and the 24um and Halpha
emissions, by recovering the star formation rate from standard recipes for HII
regions, allows us to provide star formation rate calibrations based on the
250um compact emission alone. The different locations of the Halpha and
far-ultraviolet emissions with respect to the SPIRE cool dust emission leads to
a dynamical age of a few Myr for the Halpha shells and the associated cool
dust.Comment: 4 pages, 3 figures, Accpeted for publication in the A&A Herschel
Special Issu
Reproductive and bloom patterns of Pelagia noctiluca in the Strait of Messina, Italy
Investigations on sexual reproduction of jellyfish are essential to understanding mechanisms and patterns
of outbreaks formation. Pelagia noctiluca (Forskål, 1775) (Scyphozoa) is known as the predominant
jellyfish species with direct development in Western and Central Mediterranean Sea. In this paper we
used integrated morphometric, histological, and biochemical approaches to investigate the annual
reproductive biology of P. noctiluca from the Strait of Messina (South Thyrrenian Sea), a key proliferation
area for this species due to favourable temperatures and high productivity. From November 2011 to
September 2012, P. noctiluca sexual reproduction occurred throughout the year, with two seasonal peaks
(autumn, spring) of spawning and embryonic development. Gonads of female P. noctiluca were characterized
by a large amount of mature eggs of small size (diameter < 200 mm) during high food availability,
whereas fewer, larger eggs (diameter > 200 mm) were detected during low availability of prey.
Two morphometric indexes were applied: the Gonad-Somatic Index (GSI, gonadal/somatic tissue dry
weight ratio) and Fecundity Index (FI, n eggs mm2 * gonadal dry weight). The FI showed longer
spawning periods than the GSI, providing a better causal-mechanistic explanation for the year-round
occurrence of P. noctiluca in the Strait of Messina. Protein contents of the gonads changed seasonally,
with the highest concentrations during the pre-spawning periods. We suggest that investigations on
jellyfish sexual reproduction can provide biological information relevant for understanding mechanisms
of jellyfish blooms as well as for the management of coastal zones affected by outbreaks of gelatinous
species
The circumstellar envelope around the S-type AGB star W Aql Effects of an eccentric binary orbit
The CO(J=3-2) emission from the CSE of the binary S-type AGB star W Aql has
been observed at subarcsecond resolution using ALMA. The aim of this paper is
to investigate the wind properties of the AGB star and to analyse how the known
companion has shaped the CSE. The average mass-loss rate during the creation of
the detected CSE is estimated through modelling, using the ALMA brightness
distribution and previously published single-dish measurements as observational
constraints. The ALMA observations are presented and compared to the results
from a 3D smoothed particle hydrodynamics (SPH) binary interaction model with
the same properties as the W Aql system and with two different orbital
eccentricities. Three-dimensional radiative transfer modelling is performed and
the response of the interferometer is modelled and discussed. The estimated
average mass-loss rate of W~Aql agrees with previous results. The size of the
emitting region is consistent with photodissociation models. The CO(J=3-2)
emission is dominated by a smooth component overlayed with two weak arc
patterns with different separations. The larger pattern is predicted by the
binary interaction model with separations of 10" and therefore likely due to
the known companion. It is consistent with a binary orbit with low
eccentricity. The smaller separation pattern is asymmetric and coincides with
the dust distribution, but the separation timescale (200 yrs) is not consistent
with any known process of the system. The separation of the known companions of
the system is large enough to not have a very strong effect on the
circumstellar morphology. The density contrast across the envelope of a binary
with an even larger separation will not be easily detectable, even with ALMA,
unless the orbit is strongly asymmetric or the AGB star has a much larger
mass-loss rate.Comment: 10 pages, 8 figure
Functional immunomics: Microarray analysis of IgG autoantibody repertoires predicts the future response of NOD mice to an inducer of accelerated diabetes
One's present repertoire of antibodies encodes the history of one's past
immunological experience. Can the present autoantibody repertoire be consulted
to predict resistance or susceptibility to the future development of an
autoimmune disease? Here we developed an antigen microarray chip and used
bioinformatic analysis to study a model of type 1 diabetes developing in
non-obese diabetic (NOD) male mice in which the disease was accelerated and
synchronized by exposing the mice to cyclophosphamide at 4 weeks of age. We
obtained sera from 19 individual mice, treated the mice to induce
cyclophosphamide-accelerated diabetes (CAD), and found, as expected, that 9
mice became severely diabetic while 10 mice permanently resisted diabetes. We
again obtained serum from each mouse afterCAD induction. We then analyzed the
patterns of antibodies in the individualmice to 266 different antigens spotted
on the antigen chip. We identified a select panel of 27 different antigens (10%
of the array) that revealed a pattern of IgG antibody reactivity in the pre-CAD
serathat discriminated between the mice resistant or susceptible to CAD with
100% sensitivity and 82% specificity (p=0.017). Surprisingly, the set of IgG
antibodies that was informative before CAD induction did not separate the
resistant and susceptible groups after the onset of CAD; new antigens became
criticalfor post-CAD repertoire discrimination. Thus, at least for a model
disease, present antibody repertoires can predict future disease; predictive
and diagnostic repertoires can differ; and decisive information about immune
system behavior can be mined by bioinformatic technology. Repertoires matter.Comment: See Advanced Publication on the PNAS website for final versio
Development of an application (INDITES software) that allows to integrate spatial and temporal information of a vineyard for the development of the digital terroir
ABSTRACT The terroir has been recognized as an important factor in wine quality and style, especially in European vineyards. There is currently a need for quantification of the factors that influence the definition of terroir, incorporating indexes that quantify variables such as soil, plant and climate, which has led to the definition of "Digital Terroir ". This paper proposes a methodology to develop the "digital terroir" through use of emerging technologies, as current procedures that should be use for the study and define of terroir which suffer from having replicable protocols. The study took place in Valdivieso Vineyard, Curicó, Chile, during the 2012 and 2013 seasons, under the Var. Cabernet Sauvignon, Merlot and Carmenere. The Ferari index (MULTIPLEX RESEARCH ™, FORCE-A), was used for the grapes quality quantification, which was obtained from field samples by a high density grid (20x20 m). Moreover, the soil and plant information was obtained by the use of equipment as follows, electrical conductivity (EM38), topography and exposure (RTK) and NDVI (Tetracam ADC). From the fruit quality index distribution curve (Ferari), 7 rated strata was developed by variety and year, which was used for training the respective model classification of the variables associated with the site. The classification algorithms were based on qualifying Boosting and vector machines (SVM). For model training, 75 % of the data was used and allowed the remaining 25 % to verify the calculation error (control data). The classification results were 95 %, 90 % and 80 %, of well classified area (R 2 >0.9 and Mean Absolute Error < 0.1) for Var.Carmenere, Cabernet Sauvignon and Merlot, respectively. Finally, the well defined grape quality area develop could be used for differential harvest and could be use for vineyard management when increase the yield it is the main goal. The described procedure and results are a keystone for the application of INDITES software presented on this work
Interface alloying effects in the magnetic properties of Fe nanoislands capped with different materials
We show that Fe nanoislands capped with Al, Pd, and Pt protecting layers include an alloy at the interface with the capping layer, which explains the previously known capping layer dependence on the interparticle magnetic coupling. Vibrating sample magnetometry results, for instance, are evidencing a reduction in the magnetization measured under a magnetic field of 15 mT, which is larger in the case of the Al capping and which is due to the presence of a magnetically dead interface alloy. This reduction is also observed at the atomic level using x-ray magnetic circular dichroism measurements, showing a capping layer dependence of the Fe magnetic-moment reduction that is similar for the Pd and Pt capping, and stronger for the Al capping. The trend in the magnetic properties as a function of the capping layer is explained in the light of x-ray photoemission spectroscopy results that evidence the formation of alloys at the interface between the Fe nanoislands and the capping layers. The present results highlight the strong influence of interface alloying in systems of reduced dimensionality. In particular, it is shown that the magnetic properties are strongly affected at both the atomic and macroscopic level
Bone marrow stem cell damage after three different chemotherapy regimens for advanced Hodgkin's lymphoma
The aim of this study was to evaluate the apoptotic damage to bone marrow cells caused by three chemotherapy regimens for advanced Hodgkin's lymphoma, ABVD, COPPEBVCAD and BEACOPP, which were randomly administered in the HD 2000 GISL trial. Bone marrow mononuclear cells (BMMCs) stained with anti-CD34 antibody and Annexin V, were evaluated by flow cytometry before starting chemotherapy, 30 days after completing chemotherapy and after 6 months. Results are expressed as the percentages of BMMCs positive to anti-CD34, to Annexin V or to both. Fourteen patients treated with ABVD, 11 with COPPEBVCAD and 13 with BEACOPP were evaluated before and 30 days after treatment. Late assessments were made in 6, 7 and 8 of them, respectively. No differences were found among the pretherapeutic flow cytometry findings in relation to the staging characteristics (marrow involvement included). All the regimens increased the apoptotic fraction of the whole mononuclear bone marrow cells (COPPEBVCAD did so significantly) and increased the CD34+ compartment (with significant early differences after ABVD and BEACOPP, tending to late persistence for ABVD, only). All the regimens increased the apoptotic CD34+ cells within the whole BMMC population (significantly after BEACOPP), although with a general trend to decrease in their percentage within the CD34+ compartment over time, even after the most dose-dense regimens. Based on the variations induced in the apoptotic fraction of all mononuclear and CD34+ cells, ABVD was the least toxic regimen and COPPEBVCAD the most toxic one
- …