110 research outputs found
New Optical Reddening Maps of the Large and Small Magellanic Clouds
We present new reddening maps of the SMC and LMC based on the data of the
third phase of the Optical Gravitational Lensing Experiment (OGLE III). We have
used two different methods to derive optical reddening maps. We adopt a
theoretical mean unreddened colour for the red clump in the SMC and LMC,
respectively. We subdivide the photometric data for both Clouds into subfields
and calculate the difference between the observed red clump position and the
theoretical value for each field, which provides us with the reddening value in
(V-I). Furthermore reddening values are obtained for 13490 LMC RR Lyrae ab and
1529 SMC RR Lyrae ab stars covering the whole OGLE III region of the MCs. The
observed colours (V-I) of the RR Lyrae stars are compared with the colour from
the absolute magnitudes. The absolute magnitude of each RR Lyrae star is
computed using its period and metallicity derived from Fourier decomposition of
its lightcurve. In general we find a low and uniform reddening distribution in
both Magellanic Clouds. The red clump method indicates a mean reddening of the
LMC of E(V-I) = 0.09 +/- 0.07 mag, while for the SMC E(V-I) = 0.04 +/- 0.06 mag
is obtained. With RR Lyrae stars a median value of E(V-I) = 0.11 +/- 0.06 mag
for the LMC and E(V-I) = 0.07 +/- 0.06 mag for the SMC is found. The LMC shows
very low reddening in the bar region, whereas the reddening in the star-forming
leading edge and 30 Doradus is considerably higher. In the SMC three pronounced
regions with higher reddening are visible. Two are located along the bar, while
the highest reddening is found in the star-forming wing of the SMC. In general
the regions with higher reddening are in good spatial agreement with infrared
reddening maps as well as with reddening estimations of other studies. The
position-dependent reddening values from the red clump method are available via
the Virtual Observatory interface.Comment: 15 pages, 22 Figures, AJ publishe
Reference values for leptin and adiponectin in children below the age of 10 based on the IDEFICS cohort
OBJECTIVE: To establish age- and sex-specific reference values for serum leptin and adiponectin in normal-weight 3.0-8.9-year old European children.
SUBJECTS AND METHODS: Blood samples for hormone analysis were taken from 1338 children of the IDEFICS (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS) study cohort. Only normal-weight children aged 3.0-8.9 years were included (n = 539) in our analysis. Using the General Additive Model for Location Scale and Shape, age-and sex-specific percentiles were derived. The influence of under/overweight and obesity on the proposed reference curves based on normal-weight children was investigated in several sensitivity analyses using the sample without obese children (n = 1015) and the whole study sample (n = 1338).
RESULTS: There was a negative age trend of adiponectin blood levels and a positive trend of leptin levels in boys and girls. Percentiles derived for girls were generally higher than those obtained for boys. The corresponding age-specific differences of the 97th percentile ranged from -2.2 to 4.6 mu g ml(-1) and from 2.2 to 4.8 ng ml(-1) for adiponectin and leptin, respectively.
CONCLUSIONS: According to our knowledge, these are the first reference values of leptin and adiponectin in prepubertal, normal-weight children. The presented adiponectin and leptin reference curves may allow for a more differentiated interpretation of children's hormone levels in epidemiological and clinical studies
Transcriptional response of a target plant to benzoxazinoid and diterpene allelochemicals highlights commonalities in detoxification
Background
Plants growing in proximity to other plants are exposed to a variety of metabolites that these neighbors release into the environment. Some species produce allelochemicals to inhibit growth of neighboring plants, which in turn have evolved ways to detoxify these compounds.
Results
In order to understand how the allelochemical-receiving target plants respond to chemically diverse compounds, we performed whole-genome transcriptome analysis of Arabidopsis thaliana exposed to either the benzoxazinoid derivative 2-amino- 3H-phenoxazin-3-one (APO) or momilactone B. These two allelochemicals belong to two very different compound classes, benzoxazinoids and diterpenes, respectively, produced by different Poaceae crop species.
Conclusions
Despite their distinct chemical nature, we observed similar molecular responses of A. thaliana to these allelochemicals. In particular, many of the same or closely related genes belonging to the three-phase detoxification pathway were upregulated in both treatments. Further, we observed an overlap between genes upregulated by allelochemicals and those involved in herbicide detoxification. Our findings highlight the overlap in the transcriptional response of a target plant to natural and synthetic phytotoxic compounds and illustrate how herbicide resistance could arise via pathways involved in plant-plant interaction
Millimetre observations of a sample of high-redshift obscured quasars
We present observations at 1.2 mm with MAMBO-II of a sample of z>~2
radio-intermediate obscured quasars, as well as CO observations of two sources
with the Plateau de Bure Interferometer. Five out of 21 sources (24%) are
detected at a significance of >=3sigma. Stacking all sources leads to a
statistical detection of = 0.96+-0.11 mJy and stacking only the
non-detections also yields a statistical detection, with = 0.51+-0.13
mJy. This corresponds to a typical far-infrared luminosity L_FIR~4x10^12 Lsol.
If the far-infrared luminosity is powered entirely by star-formation, and not
by AGN-heated dust, then the characteristic inferred star-formation rate is
~700 Msol yr-1. This far-infrared luminosity implies a dust mass of
M_dust~3x10^8 Msol. We estimate that such large dust masses on kpc scales can
plausibly cause the obscuration of the quasars. We present dust SEDs for our
sample and derive a mean SED for our sample. This mean SED is not well fitted
by clumpy torus models, unless additional extinction and far-infrared
re-emission due to cool dust are included. There is a hint that the host
galaxies of obscured quasars must have higher far-infrared luminosities and
cool-dust masses and are therefore often found at an earlier evolutionary phase
than those of unobscured quasars. For one source at z=2.767, we detect the
CO(3-2) transition, with S_CO Delta nu=630+-50 mJy km s-1, corresponding to
L_CO(3-2)= 3.2x10^7 Lsol, or L'_CO(3-2)=2.4x10^10 K km s-1 pc2. For another
source at z=4.17, the lack of detection of the CO(4-3) line yields a limit of
L'_CO(4-3)<1x10^10 K km s-1 pc2. Molecular gas masses, gas depletion timescales
and gas-to-dust ratios are estimated (Abridged).Comment: Accepted by ApJ, 25 pages, 11 figures, 4 table
Shrubland primary production and soil respiration diverge along European climate gradient
Above- and belowground carbon (C) stores of terrestrial ecosystems are vulnerable to environmental change. Ecosystem C balances in response to environmental changes have been quantified at individual sites, but the magnitudes and directions of these responses along environmental gradients remain uncertain. Here we show the responses of ecosystem C to 8–12 years of experimental drought and night-time warming across an aridity gradient spanning seven European shrublands using indices of C assimilation (aboveground net primary production: aNPP) and soil C efflux (soil respiration: Rs). The changes of aNPP and Rs in response to drought indicated that wet systems had an overall risk of increased loss of C but drier systems did not. Warming had no consistent effect on aNPP across the climate gradient, but suppressed Rs more at the drier sites. Our findings suggest that above- and belowground C fluxes can decouple, and provide no evidence of acclimation to environmental change at a decadal timescale. aNPP and Rs especially differed in their sensitivity to drought and warming, with belowground processes being more sensitive to environmental change
Gas and dust in a z=2.8 obscured quasar
We present new detections of the CO(5-4), CO(7-6), [CI](1-0) and [CI](2-1)
molecular and atomic line transitions towards the unlensed, obscured quasar
AMS12 (z=2.7672), observed with the IRAM PdBI. This is the first unlensed, high
redshift source to have both [CI] transitions detected. Continuum measurements
between 70 m and 3 mm are used to constrain the FIR SED, and we find a
best fit FIR luminosity of log[Lfir/Lsol] = 13.5+/-0.1, dust temperature T_d =
88+/-8 K and emissivity index {\beta} = 0.6+/-0.1. The highly-excited molecular
gas probed by CO(3-2), (5-4) and (7-6), is modelled with large velocity
gradient (LVG) models. The gas kinetic temperature T_g, density n(H2), and the
characteristic size r0, are determined using the dust temperature from the FIR
SED as a prior for the gas temperature. The best fitting parameters are T_g =
90+/-8 K, n(H2) = 10^(3.9+/-0.1) cm^(-3) and r0 = 0.8+/-0.04 kpc. The ratio of
the [CI] lines gives a [CI] excitation temperature of 43+/-10 K, indicating the
[CI] and the high-excitation CO are not in thermal equilibrium. The [CI]
excitation temperature is below that of T_d and T_g of the high-excitation CO,
perhaps because [CI] lies at a larger radius where there may also be a large
reservoir of CO at a cooler temperature, perhaps detectable through the
CO(1-0). Using the [CI](1-0) line we can estimate the strength of the CO(1-0)
line and hence the gas mass. This suggests that a significant fraction (~30%)
of the molecular gas is missed from the high-excitation line analysis. The
Eddington limited black hole mass is found from the bolometric luminosity to be
Mbh >~ 1.5x10^9 Msol. Along with the stellar mass of 3x10^11 Msol, these give a
black hole - bulge mass ratio of Mbh/Mbulge >~ 0.005. This is in agreement with
studies on the evolution of the Mbh/Mbulge relationship at high redshifts,
which find a departure from the local value ~0.002.Comment: Accepted by MNRAS, 17 pages, 9 figure
Penggunaan Pendekatan Kuis Tim Untuk Meningkatkan Tanggung Jawab Individu Dalam Kelompok Belajar Geografi Siswa Kelas X-8 SMA Negeri 1 Durenan Trenggalek
Self develovment trough active learning by using Quiz Team Approach is centered on thestudent\u27s variety during the activities in turning the dinamic of the student group in learning. It begins fromunderstanding the concept of learning material, making questions to design group activity, deviding the groupwork every, planning the presentation until giving such kind of achievement in the form of score and crownedthe best group for every session. This research is aimed to increase individual responbility in finishing theassigment in a group, dua two self development process.The subject of this research is the students of X-8, 2014/2015 Academic Year. This classroom actionresearch is designed into 2 cycles. Wich every cycle consist of many steps: planning, doing the research,observation, reflexion. The result of action in one cycle is in the form of the student\u27s active, the developmentof self aspect self improvement from the students, is evaluated as the material to design the next action for thenext cycle. The material used as the object of the research is Quiz Team Active Learning model and theimplementation.The research result showed that the applied of active learning model by using Quiz Team Approachbe able to increase individual responsibilty in a group study. This learning model, the researcher meant byusing Quiz Team Approach, got positive response from students by the indicator from the result of “angket”analysis at the end of activity and the increasing of finishing the assignment and “unjuk kerja”. The student\u27sachievement is also become raising in 1st cycle the average score of formative 72,50 and the “ketuntasan” ofthe learning result is 78,57%, meanwhile at the 2nd cycle, its become increasing on the average of formativescore 80,35 and 90,47%
Structure-function analysis of peroxidasin provides insight into the mechanism of collagen IV crosslinking
Basement membranes provide structural support and convey regulatory signals to cells in diverse tissues. Assembly of collagen IV into a sheet-like network is a fundamental mechanism during the formation of basement membranes. Peroxidasin (PXDN) was recently described to catalyze crosslinking of collagen IV through the formation of sulfilimine bonds. Despite the significance of this pathway in tissue genesis, our understanding of PXDN function is far from complete. In this work we demonstrate that collagen IV crosslinking is a physiological function of mammalian PXDN. Moreover, we carried out structure-function analysis of PXDN to gain a better insight into its role in collagen IV synthesis. We identify conserved cysteines in PXDN that mediate the oligomerization of the protein into a trimeric complex. We also demonstrate that oligomerization is not an absolute requirement for enzymatic activity, but optimal collagen IV coupling is only catalyzed by the PXDN trimers. Localization experiments of different PXDN mutants in two different cell models revealed that PXDN oligomers, but not monomers, adhere on the cell surface in "hot spots," which represent previously unknown locations of collagen IV crosslinking. ©2015 Published by Elsevier Inc
- …