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The digestive microbiota plays a decisive role in shaping and preserving health throughout life. Rabbit younglings are born with a sterile digestive tract but then it gets progressively colonised by the microbiota of the nursing mother, by entering in contact with or ingesting the maternal droppings present in the nest. Here we posit that (i) offspring survival and (ii) lifespan of female rabbits are linked to how diverse their microbiota are. To test the hypothesis that maternal microbiota evolves in females having had different levels of offspring survival in their lifetime, we obtained 216 hard faecal samples from 75 female rabbits at ages 19.6, 31.6, 62.6 and 77.6 weeks. The annual mean offspring survival (MOS) at 64 days was calculated for each female then crossed against three alpha-diversity indexes (operational taxonomic units (OTUs), inverse Simpson index and Shannon index). Age was also analysed against these three parameters. The alpha-diversity indexes of the female faecal microbiota did not correlate with MOS, but they did decrease with age (e.g. from 712 OTUs at age 19.6 weeks to 444 OTUs at 77.6 weeks; P < 0.05). The age effect was also found in beta-diversity non-metric multidimensional scaling plots using the Bray–Curtis dissimilarity index and the unweighted UniFrac index but not for MOS. The ability of the microbiota composition from the faecal samples of young females (19.6 weeks old) to predict their lifespan was also evaluated. After subdividing the initial population into two classes (females that weaned a maximum of three litters and females living longer), we found no clear distinction between these two classes. To our knowledge, this is the first long-term study to characterise the gut microbiota of adult female rabbits through their reproductive life, thus laying foundations for using the gut microbiota data and its influence in studies on adult rabbits.
In young rabbit, digestive disorders are frequently observed around weaning. Stimulating the onset of feed intake in the suckling rabbit might be a way to promote gut health. The aim of this study was to determine the rabbit’s acceptability for different feed presentations and its preferences for flavours at an early stage of life. Two trials were conducted to evaluate the effects of physical form and flavouring on creep feed attractiveness. All the diets tested were provided in the nest from 3 to 17 days, and the daily intake per litter was recorded as of 8 days of age. In the first trial, five feed presentations were tested separately (n = 60 litters). Three dry presentations were chosen: commercial pellet (P), crumb from commercial pellet (cP) and crumb from beet pulp pellet (cBP). Hydrated feeds were also provided with either raw fodder beetroot (B) or a semi-solid feed in agar gel form produced with fodder beetroot juice and pulp (gB). In the second trial, double-choice tests were performed on four feed gels (n = 72 litters), leading to six comparison treatments. These agar gels were made of pellet mash without or with a sensory additive: one non-odorised control gel and three gels with 0.20% banana flavour, 0.06% red berry flavour and 0.10% vanilla flavour, respectively. In the first trial, kits ate more gB in fresh matter than other feed presentations (P < 0.001), with a total intake of 7.0 ± 1.8 g/rabbit from 8 to 17 days. In DM, the total consumption of pellets P (1.6 ± 0.4 g of DM/rabbit) was the highest together with the gB form (1.4 ± 0.4 g of DM/rabbit), whereas cBP was barely consumed (0.3 ± 0.1 g of DM/rabbit). Gel feed supplemented with vanilla was slightly more consumed than other flavoured and non-odorised gels (relative consumption of 57% when compared to control gel; P = 0.001). The gel feed intake was independent of the milk intake but was correlated with the litter weight at 3 days (r = 0.40, P < 0.001). In both trials, rabbit growth before and after weaning was not affected by the type of creep feed provided. Our results confirmed that providing creep feed promotes the solid intake of rabbits at early stages. Gel feed form motivated rabbits to eat and vanilla flavour supplementation increased the feed palatability. Those creep feed characteristics should be explored further for seeking effective stimulation of the onset of the feed intake in suckling rabbit.
Retrospective data evaluated increases in advanced medical support for children with medically attended acute respiratory illness (MAARI) during influenza outbreak periods (IOP). Advanced support included hospitalisation, intensive care unit admission, or mechanical ventilation, for children aged 0–17 years hospitalised in Maryland's 50 acute-care hospitals over 12 influenza seasons. Weekly numbers of positive influenza tests in the Maryland area defined IOP for each season as the fewest consecutive weeks, including the peak week containing at least 85% of positive tests with a 2-week buffer on either side of the IOP. Peak IOP (PIOP) was defined as four consecutive weeks containing the peak week with the most number of positive influenza tests. Off-PIOP was defined as the ‘shoulder’ weeks during each IOP. Non-influenza season (NIS) was the remaining weeks of that study season. Rate ratios of mean daily MAARI-related admissions resulting in advanced medical support outcomes during PIOP or Off-PIOP were compared with the NIS and were significantly elevated for all 12 study seasons combined. The results suggest that influenza outbreaks are associated with increased advanced medical support utilisation by children with MAARI. We feel that this data may help preparedness for severe influenza epidemics or pandemic.
Wolf-Rayet HII galaxies are local metal-poor star-forming galaxies, observed when the most massive stars are evolving from O stars to WR stars, making them template systems to study distant starbursts. We have been performing a program to investigate the interplay between massive stars and gas in WR HII galaxies using IFS. Here, we highlight some results from the first 3D spectroscopic study of Mrk 178, the closest metal-poor WR HII galaxy, focusing on the origin of the nebular HeII emission and the aperture effects on the detection of WR features.
We present results of ALMA (Cycle-0) observations of the CO (6-5) line emission and the 435μm continuum of two nearby luminous infrared galaxies (LIRGs) NGC 34 (a major merger with an AGN) and NGC 1614 (a minor merger with a circum-nuclear starburst). Using receivers in the highest frequency ALMA band available (Band-9), these observations achieved the best angular resolutions (∼0″.25) for ALMA Cycle-0 observations and resolved for the first time distributions of warm dense molecular gas (n > 105 cm−3, T > 100 K) in LIRGs with spatial resolutions better than 100 pc. Our ALMA data show a very tight correlation between the CO (6-5) line emission and the 435μm dust continuum emission, suggesting the warm dense molecular gas dominates the ISM in the central kpc of LIRGs, and gas heating and dust heating in the warm dense gas cores are strongly coupled. On the other hand, we saw very different spatial distributions and kinematic properties of warm dense gas in the two LIRGs, indicating that physical conditions in the ISM can be very different in different LIRGs.
We resolve spatially the star formation history of 300 nearby galaxies from the CALIFA integral field survey to investigate: a) the radial structure and gradients of the present stellar populations properties as a function of the Hubble type; and b) the role that plays the galaxy stellar mass and stellar mass surface density in governing the star formation history and metallicity enrichment of spheroids and the disks of galaxies. We apply the fossil record method based on spectral synthesis techniques to recover spatially and temporally resolved maps of stellar population properties of spheroids and spirals with galaxy mass from 109 to 7×1011 M⊙. The individual radial profiles of the stellar mass surface density (μ⋆), stellar extinction (AV), luminosity weighted ages (〈logage〉L), and mass weighted metallicity (〈log Z/Z⊙〉M) are stacked in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc and Sd). All these properties show negative gradients as a sight of the inside-out growth of massive galaxies. However, the gradients depend on the Hubble type in different ways. For the same galaxy mass, E and S0 galaxies show the largest inner gradients in μ⋆; and Andromeda-like galaxies (Sb with log M⋆ (M⊙) ∼ 11) show the largest inner age and metallicity gradients. In average, spiral galaxies have a stellar metallicity gradient ∼ −0.1 dex per half-light radius, in agreement with the value estimated for the ionized gas oxygen abundance gradient by CALIFA. A global (M⋆-driven) and local (μ⋆-driven) stellar metallicity relation are derived. We find that in disks, the stellar mass surface density regulates the stellar metallicity; in spheroids, the galaxy stellar mass dominates the physics of star formation and chemical enrichment.
DART-Ray is a 3D ray-tracing dust radiative transfer (RT) code that can be used to derive stellar and dust emission maps of galaxy models and simulations with arbitrary geometries. In addition to the previously published RT algorithm, we have now included in DART-Ray the possibility of calculating the stocastically heated dust emission from each volume element within a galaxy. To show the capabilities of the code, we performed a high-resolution (26 pc) RT calculation for a galaxy N-body+SPH simulation. The simulated galaxy we considered is characterized by a nuclear disc and a flocculent spiral structure. We analysed the derived galaxy maps for the global and local effects of dust on the galaxy attenuation as well as the contribution of scattered radiation to the predicted observed emission. In addition, by performing an additional RT calculation including only the stellar volume emissivity due to young stellar populations (SPs), we derived the contribution to the total dust emission powered by young and old SPs. Full details of this work will be presented in a forthcoming publication.
Two new integral field units (IFUs) were installed recently on the WIYN Observatory's 3.5-meter telescope at Kitt Peak. These unique IFUs contain fibers of different sizes in the same head. This design allows smaller fibers to sample regions of higher surface brightness, providing higher spatial resolution while maintaining adequate signal-to-noise (S/N). Conversely, larger fibers maintain S/N at the expense of spatial resolution in the lower surface brightness regions of galaxies. The new IFUs were built with funds from NSF award ATI-0804576.
The morphological, spectroscopic and kinematical properties of the warm interstellar medium (wim) in early-type galaxies (ETGs) hold key observational constraints to nuclear activity and the buildup history of these massive quiescent systems. High-quality integral field spectroscopy (IFS) data with a wide spectral and spatial coverage, such as those from the CALIFA survey, offer a precious opportunity for advancing our understanding in this respect. We use deep IFS data from CALIFA (califa.caha.es) to study the wim over the entire extent and optical spectral range of 32 nearby ETGs. We find that all ETGs in our sample show faint (Hα equivalent width EW(Hα)∼0.5 … 2 Å) extranuclear nebular emission extending out to ≥2 Petrosian50 radii. Confirming and strengthening our conclusions in Papaderos et al. (2013, hereafter P13) we argue that ETGs span a broad continuous sequence with regard to the properties of their wim, and they can be roughly subdivided into two characteristic classes. The first one (type i) comprises ETGs with a nearly constant EW(Hα)∼1–3 Å in their extranuclear component, in quantitative agreement with (even though, no proof for) the hypothesis of photoionization by the post-AGB stellar component being the main driver of extended wim emission. The second class (type ii) consists of virtually wim-evacuated ETGs with a large Lyman continuum (Lyc) photon escape fraction and a very low (≤0.5 Å) EW(Hα) in their nuclear zone. These two ETG classes appear indistinguishable from one another by their LINER-specific emission-line ratios. Additionally, here we extend the classification by P13 by the class i+ which stands for a subset of type i ETGs with low-level star-forming activity in contiguous spiral-arm like features in their outermost periphery. These faint features, together with traces of localized star formation in several type i&i+ systems point to a non-negligible contribution from young massive stars to the global ionizing photon budget in ETGs.
Methods to recover the fossil record of galaxy evolution encoded in their optical spectra have been instrumental in processing the avalanche of data from mega-surveys along the last decade, effectively transforming observed spectra onto a long and rich list of physical properties: from stellar masses and mean ages to full star formation histories. This promoted progress in our understanding of galaxies as a whole. Yet, the lack of spatial resolution introduces undesirable aperture effects, and hampers advances on the internal physics of galaxies. This is now changing with 3D surveys. The mapping of stellar populations in data-cubes allows us to figure what comes from where, unscrambling information previously available only in integrated form. This contribution uses our starlight-based analysis of 300 CALIFA galaxies to illustrate the power of spectral synthesis applied to data-cubes. The selected results highlighted here include: (a) The evolution of the mass-metallicity and mass-density-metallicity relations, as traced by the mean stellar metallicity. (b) A comparison of star formation rates obtained from Hα to those derived from full spectral fits. (c) The relation between star formation rate and dust optical depth within galaxies, which turns out to mimic the Schmidt-Kennicutt law. (d) PCA tomography experiments.
We present the ambitious project J-PAS, that will cover 8000 deg2 of the northern sky with 54 narrow-band (∼145Å) contiguous filters, all of them in the optical range (3700Å-9200Å). J-PAS will provide a low resolution spectra (R ∼ 50) in every pixel of the northern sky by 2020, leading to excellent photometric redshifts (0.3% uncertainty) of 100 million sources. J-PAS will permit the study of the 2D properties of nearby galaxies with unprecedented statistics. Some viable studies are the distribution of the star formation rate traced by Hα, the stellar populations gradients in elliptical galaxies up to a few effective radii, or the impact of environment in galaxy properties. In summary, J-PAS will bring a superb data set for 3D analysis in the local Universe.
We are conducting a multiwavelength study of XUV discs in nearby, gas-rich spiral galaxies combining the available UV (GALEX) observations with H i data obtained at the ATCA as part of the Local Volume HI Survey (LVHIS) project and multi-object fibre spectroscopy obtained using the 2dF/AAOmega instrument at the 3.9m AAT. Here we present the results of the multiwavelength analysis of the galaxy pair NGC 1512/1510. The H i distribution of NGC 1512 is very extended with two pronounced spiral/tidal arms. Hundreds of independent UV-bright regions are associated with dense H i clouds in the galaxy outskirts. We confirm the detection of ionized gas in the majority of them and characterize their physical properties, chemical abundances and kinematics. Both the gas distribution andthe distribution of the star-forming regions are affected by gravitational interactionwith the neighbouring blue compact dwarf galaxy NGC 1510. Our multiwavelength analysis provides new clues about local star-formation processes, the metal redistribution in the outer gaseous discs of spiral galaxies, the importance of galaxy interactions, the fate of the neutral gas and the chemical evolution in nearby galaxies.
We continue our search for extragalactic Carbon Radio Recombination Lines (CRRL) in M82 with the LOw Frequency ARray (LOFAR; van Haarlem et al.2013). The goal of our project is to determine the physical conditions of the cold neutral gas in this object, for which low frequency radio recombination lines can provide a sensitive probe.
The MIRAGE sample (Merging & isolated high-redshift AMR galaxies; Perret 2014, PhD dissertation; Perret et al. 2014, AA 562, 1) has been built in order to understand the contribution of the merger processes to the mass assembly in the MASSIV (Mass Assembly Survey with SINFONI in VVDS, Contini et al. 2012, AA 539, 91) sample. It consists of a sample of idealized simulations based on the RAMSES code; the initial conditions were designed to reproduce the physical properties of the most gas-rich young galaxies. The sample is composed of 20 simulations of mergers exploring the initial parameters of mass and orientation of the disks with a spatial resolution reaching 7 parsecs.
We investigate the environmental dependence of the mass-metallicty (MZ) relation and its connection to galaxy stellar structures and morphologies. In our studies, we analyze galaxies in massive clusters at z ∼ 0.4 from the CLASH (HST) and CLASH-VLT surveys and measure their gas metallicities, star-formation rates, stellar structures and morphologies. We establish the MZ relation for 90 cluster and 40 field galaxies finding a shift of ∼ − 0.3 dex in comparison to the local trends seen in SDSS for the majority of galaxies with logM < 10.5. We do not find significant differences of the distribution of 4 distinct morphological types that we introduce by our classification scheme (smooth, disc-like, peculiar, compact). Some variations between cluster and field galaxies in the MZ relation are visible at the high mass end. However, obvious trends for cluster specific interactions (enhancements or quenching of SFRs) are missing. In particular, galaxies with peculiar stellar structures that hold signs for galaxy interactions, are distributed in a similar way as disc-like galaxies - in SFRs, masses and O/H abundances. We further show that our sample falls around an extrapolation of the star-forming main sequence (the SFR-M∗ relation) at this redshift, indicating that emission-line selected samples do not have preferentially high star-formation rates (SFRs). However, we find that half of the high mass cluster members (M∗ > 1010M⊙) lie below the main sequence which corresponds to the higher mass objects that reach solar abundances in the MZ diagram.
The late-type spiral NGC 2770 hosted 3 Type Ib supernovae (SNe) in or next to star-forming regions in its outer spiral arms. We study the properties of the SN sites and the galaxy at different spatial resolutions to infer propeties of the SN progenitors and the SF history of the galaxy. Several 3D techniques are used and, for the first time, we present images of metallicity, shocks and stellar population ages from OSIRIS/GTC imaging with tunable narrowband filters.
Several studies demonstrating that central line–associated bloodstream infections (CLABSIs) are preventable prompted a national initiative to reduce the incidence of these infections.
We conducted a collaborative cohort study to evaluate the impact of the national “On the CUSP: Stop BSI” program on CLABSI rates among participating adult intensive care units (ICUs). The program goal was to achieve a unit-level mean CLABSI rate of less than 1 case per 1,000 catheter-days using standardized definitions from the National Healthcare Safety Network. Multilevel Poisson regression modeling compared infection rates before, during, and up to 18 months after the intervention was implemented.
A total of 1,071 ICUs from 44 states, the District of Columbia, and Puerto Rico, reporting 27,153 ICU-months and 4,454,324 catheter-days of data, were included in the analysis. The overall mean CLABSI rate significantly decreased from 1.96 cases per 1,000 catheter-days at baseline to 1.15 at 16–18 months after implementation. CLABSI rates decreased during all observation periods compared with baseline, with adjusted incidence rate ratios steadily decreasing to 0.57 (95% confidence intervals, 0.50–0.65) at 16–18 months after implementation.
Coincident with the implementation of the national “On the CUSP: Stop BSI” program was a significant and sustained decrease in CLABSIs among a large and diverse cohort of ICUs, demonstrating an overall 43% decrease and suggesting the majority of ICUs in the United States can achieve additional reductions in CLABSI rates.
In this talk, I will present the result of high resolution numerical simulations of disk galaxies with various bulge/disk ratios evolving isolated, showing that:
• Most of migration takes place when the bar strength is high and decreases in the phases of low activity (in agreement with the results by Brunetti et el. 2011, Minchev et al. 2011).
• Most of the stars inside the corotation radius (CR) do not migrate in the outer regions, but stay confined in the inner disk, while stars outside CR can migrate either inwards or outwards, diffusing over the whole disk.
• Migration is accompanied by significative azimuthal variations in the metallicity distribution, of the order of 0.1 dex for an initial gradient of ~-0.07 dex/kpc.
• Boxy bulges are an example of stellar structures whose properties (stellar content, vertical metallicity, [α/Fe] and age gradients, ..) are affected by radial migration (see also Fig. 1).
A year-long intervention trial was conducted to characterise the responses of multiple biomarkers of Se status in healthy American adults to supplemental selenomethionine (SeMet) and to identify factors affecting those responses. A total of 261 men and women were randomised to four doses of Se (0, 50, 100 or 200 μg/d as l-SeMet) for 12 months. Responses of several biomarkers of Se status (plasma Se, serum selenoprotein P (SEPP1), plasma glutathione peroxidase activity (GPX3), buccal cell Se, urinary Se) were determined relative to genotype of four selenoproteins (GPX1, GPX3, SEPP1, selenoprotein 15), dietary Se intake and parameters of single-carbon metabolism. Results showed that supplemental SeMet did not affect GPX3 activity or SEPP1 concentration, but produced significant, dose-dependent increases in the Se contents of plasma, urine and buccal cells, each of which plateaued by 9–12 months and was linearly related to effective Se dose (μg/d per kg0·75). The increase in urinary Se excretion was greater for women than men, and for individuals of the GPX1 679 T/T genotype than for those of the GPX1 679 C/C genotype. It is concluded that the most responsive Se-biomarkers in this non-deficient cohort were those related to body Se pools: plasma, buccal cell and urinary Se concentrations. Changes in plasma Se resulted from increases in its non-specific component and were affected by both sex and GPX1 genotype. In a cohort of relatively high Se status, the Se intake (as SeMet) required to support plasma Se concentration at a target level (Sepl-target) is: .