74 research outputs found
Flux- and volume-limited groups/clusters for the SDSS galaxies: catalogues and mass estimation
We provide flux-limited and volume-limited galaxy group and cluster
catalogues, based on the spectroscopic sample of the SDSS data release 10
galaxies. We used a modified friends-of-friends (FoF) method with a variable
linking length in the transverse and radial directions to identify as many
realistic groups as possible. The flux-limited catalogue incorporates galaxies
down to m_r = 17.77 mag. It includes 588193 galaxies and 82458 groups. The
volume-limited catalogues are complete for absolute magnitudes down to M_r =
-18.0, -18.5, -19.0, -19.5, -20.0, -20.5, and -21.0; the completeness is
achieved within different spatial volumes, respectively. Our analysis shows
that flux-limited and volume-limited group samples are well compatible to each
other, especially for the larger groups/clusters. Dynamical mass estimates,
based on radial velocity dispersions and group extent in the sky, are added to
the extracted groups. The catalogues can be accessed via http://cosmodb.to.ee
and the Strasbourg Astronomical Data Center (CDS).Comment: 16 pages, 18 figures, 2 tables, accepted for publication in A&
Implications of climate change for ecological reference conditions, thresholds and classification systems for European lakes
This report focuses on potential effects of climate change on ecological reference conditions and on ecological responses to nutrient pressures in lakes, especially threshold-type and non-linear responses. Reference conditions and thresholds responses are both fundamental for na-tional ecological classification systems according to the European Water Framework Direc-tive (WFD), for defining reference values and management targets (Good/Moderate class boundary) respectively. Effects of climate change on these components therefore have impor-tant implications for assessment of ecological status and management of lakes. We have addressed the effects of climate change on lakes by an extensive literature review, as well as by analysing palaeolimnological datasets, large-scale European datasets and long-term time series for four individual lakes in Norway, Estonia and Germany (case studies). The cli-matic changes considered include increased temperature, increased precipitation (and conse-quently increased content of organic matter) and reduced precipitation (and consequently re-duced water levels and increased salinity). The literature review describes effects of climate change on reference conditions for each biological quality element (BQE; phytoplankton, macrophytes, macroinvertebrates and fish); of these phytoplankton and fish tend to be most sensitive to climate change. Results from new palaeolimnological analyses suggest that nutrients are the dominant driver of diatom compositional change, and there is insufficient evidence to suggest how reference conditions should be modified in light of climate change. Nonetheless further work is required to explore the relationship between diatoms and climate change in more detail. Analysis of chlorophyll a (chl-a) in European reference lakes suggest that under future climatic condi-tions, increased temperature in combination with increased TP (due to increased winter pre-cipitation) will lead to increased chl-a concentrations, although the effects will vary with the lake type (notably the humic level). Large-scale analysis of cyanobacteria in North-European lakes, considering both lake typology and climatic variables, suggest that the risk of exceed-ing regulatory thresholds for cyanobacteria will increase with future higher temperature, but also that this tendency to some degree might be compensated by increased precipitation. The four case studies provide more detailed examples of interactions between climatic factors and nutrient pressures on plankton communities, and demonstrate some of the complexity in-volved in ecological responses to climate change in lakes. Finally, the report provides a set of recommendations for river basin management, considering impacts of climate change on ref-erence conditions and ecological thresholds, and the implications for WFD-based classifica-tion systems
Relative distances of Omega Centauri and 47 Tucanae
We present precise optical and near-infrared ground-based photometry of two
Globular Clusters (GCs): Omega Cen and 47 Tuc. These photometric catalogs are
unbiased in the Red Giant Branch (RGB) region close to the tip. We provide new
estimates of the RGB tip (TRGB) magnitudes--m_I(TRGB)=9.84+/-0.05, Omega Cen;
m_I(TRGB)=9.46+/-0.06, 47 Tuc--and use these to determine the relative
distances of the two GCs. We find that distance ratios based on different
calibrations of the TRGB, the RR Lyrae stars and kinematic distances agree with
each other within one sigma. Absolute TRGB and RR Lyrae distance moduli agree
within 0.10--0.15 mag, while absolute kinematic distance moduli are 0.2--0.3
mag smaller. Absolute distances to 47 Tuc based on the
Zero-Age-Horizontal-Branch and on the white dwarf fitting agree within 0.1 mag,
but they are 0.1--0.3 mag smaller than TRGB and RR Lyrae distances.Comment: 5 pages, 4 figures, accepted for publication by ApJ
Immune response to a conserved enteroviral epitope of the major capsid VP1 protein is associated with lower risk of cardiovascular disease
Background Major cardiac events including myocardial infarction (MI) are associated with viral infections. However, how specific infections contribute to the cardiovascular insults has remained largely unclear. Methods We employed next generation phage display mimotope-variation analysis (MVA) to explore the link between antibody-based immune response and severe cardiovascular conditions. Here, we used a case-control design, including the first-stage discovery cohort (n = 100), along with cohorts for second-stage discovery (n = 329) and validation (n = 466). Findings We observed strong antibody response to the peptide antigens with Gly-Ile-X-Asp (G-I-X-D) core structure in healthy individuals but not in patients with MI. Analysis of the origin of this epitope linked it with the N-terminus of the VP1 protein of poliovirus 3 (PV3), but also other species of picornaviruses. Consistently, we found low levels of antibody response to the G-I-X-D epitope in individuals with severe cardiac disease complications. Interpretation Our findings imply that antibody response to the G-I-X-D epitope is associated with polio vaccinations and that high antibody levels to this epitope could discriminate healthy individuals from prospective MI patients as a blood-derived biomarker. Together, these findings highlight the importance of epitope-specific antibody response and suggest that protective immunity against the polio- and non-polio enteroviral infections support improved cardiovascular health. Copyright (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Peer reviewe
A Social Sciences and Humanities research agenda for transport and mobility in Europe: key themes and 100 research questions
Transport and mobility systems need to be transformed to meet climate change goals and reduce negative environmental and social effects. Despite EU policies having targeted such problems for more than three decades, transitions have been slow and geographically uneven. For effective change to happen, transport and mobility research needs fresh perspectives and better integration of knowledge from the Social Sciences and Humanities. Based on a Horizon Scanning approach, which allowed for a great deal of openness and variety in scholarly viewpoints, this paper presents a novel research agenda consisting of 8 themes and 100 research questions that may contribute to achieving environmentally sustainable mobility transitions within Europe. This research agenda highlights the need to not only support technological solutions for low-carbon mobility, but the importance of transformative policies that include new processes of knowledge production, civic participation and epistemic justice. We contend that the agenda points to the need for further research on the dynamics of science-society interactions
Response of Coastal Fishes to the Gulf of Mexico Oil Disaster
The ecosystem-level impacts of the Deepwater Horizon disaster have been largely unpredictable due to the unique setting and magnitude of this spill. We used a five-year (2006â2010) data set within the oil-affected region to explore acute consequences for early-stage survival of fish species inhabiting seagrass nursery habitat. Although many of these species spawned during spring-summer, and produced larvae vulnerable to oil-polluted water, overall and species-by-species catch rates were high in 2010 after the spill (1,989±220 fishes km-towedâ1 [ÎŒ ± 1SE]) relative to the previous four years (1,080±43 fishes km-towedâ1). Also, several exploited species were characterized by notably higher juvenile catch rates during 2010 following large-scale fisheries closures in the northern Gulf, although overall statistical results for the effects of fishery closures on assemblage-wide CPUE data were ambiguous. We conclude that immediate, catastrophic losses of 2010 cohorts were largely avoided, and that no shifts in species composition occurred following the spill. The potential long-term impacts facing fishes as a result of chronic exposure and delayed, indirect effects now require attention
TOPz: Photometric redshifts for J-PAS
The importance of photometric galaxy redshift estimation is rapidly
increasing with the development of specialised powerful observational
facilities. We develop a new photometric redshift estimation workflow TOPz to
provide reliable and efficient redshift estimations for the upcoming
large-scale survey J-PAS which will observe 8500 deg2 of the northern sky
through 54 narrow-band filters. TOPz relies on template-based photo-z
estimation with some added J-PAS specific features and possibilities. We
present TOPz performance on data from the miniJPAS survey, a precursor to the
J-PAS survey with an identical filter system. First, we generated spectral
templates based on the miniJPAS sources using the synthetic galaxy spectrum
generation software CIGALE. Then we applied corrections to the input photometry
by minimising systematic offsets from the template flux in each filter. To
assess the accuracy of the redshift estimation, we used spectroscopic redshifts
from the DEEP2, DEEP3, and SDSS surveys, available for 1989 miniJPAS galaxies
with r < 22 magAB. We also tested how the choice and number of input templates,
photo-z priors, and photometric corrections affect the TOPz redshift accuracy.
The general performance of the combination of miniJPAS data and the TOPz
workflow fulfills the expectations for J-PAS redshift accuracy. Similarly to
previous estimates, we find that 38.6% of galaxies with r < 22 mag reach the
J-PAS redshift accuracy goal of dz/(1 + z) < 0.003. Limiting the number of
spectra in the template set improves the redshift accuracy up to 5%, especially
for fainter, noise-dominated sources. Further improvements will be possible
once the actual J-PAS data become available.Comment: 20 pages, 24 figure
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Atmospheric stilling leads to prolonged thermal stratification in a large shallow polymictic lake
To quantify the effects of recent and potential future decreases in surface wind speeds on lake thermal stratification, we apply the one-dimensional process-based model MyLake to a large, shallow, polymictic lake, VÔrtsjÀrv. The model is validated for a 3-year period and run separately for 28 years using long-term daily atmospheric forcing data from a nearby meteorological station. Model simulations show exceptionally good agreement with observed surface and bottom water temperatures during the 3-year period. Similarly, simulated surface water temperatures for 28 years show remarkably good agreement with long-term in situ water temperatures. Sensitivity analysis demonstrates that decreasing wind speeds has resulted in substantial changes in stratification dynamics since 1982, while increasing air temperatures during the same period had a negligible effect. Atmospheric stilling is a phenomenon observed globally, and in addition to recent increases in surface air temperature, needs to be considered when evaluating the influence of climate change on lake ecosystems
Challenging fear: Chemical alarm signals are not causing morphology changes in crucian carp (Carassius carassius)
Crucian carp develops a deep body in the presence of chemical cues from predators, which makes the fish less vulnerable to gape-limited predators. The active components originate in conspecifics eaten by predators, and are found in the filtrate of homogenised conspecific skin. Chemical alarm signals, causing fright reactions, have been the suspected inducers of such morphological changes. We improved the extraction procedure of alarm signals by collecting the supernatant after centrifugation of skin homogenates. This removes the minute particles that normally make a filtered sample get turbid. Supernatants were subsequently diluted and frozen into ice-cubes. Presence of alarm signals was confirmed by presenting thawed ice-cubes to crucian carp in behaviour tests at start of laboratory growth experiments. Frozen extracts were added further on three times a week. Altogether, we tested potential body-depth-promoting properties of alarm signals twice in the laboratory and once in the field. Each experiment lasted for a minimum of 50 days. Despite growth of crucian carp in all experiments, no morphology changes were obtained. Accordingly, we conclude that the classical alarm signals that are releasing instant fright reactions are not inducing morphological changes in this species. The chemical signals inducing a body-depth increase are suspected to be present in the particles removed during centrifugation (i.e., in the precipitate). Tissue particles may be metabolized by bacteria in the intestine of predators, resulting in water-soluble cues. Such latent chemical signals have been found in other aquatic organisms, but hitherto not reported in fishe
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