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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.
As practice guidelines recommend to maintain antidepressant treatments for a long duration after improvement of symptoms in order to prevent relapse or recurrence, our objectives were to explore the duration of the antidepressant drug treatment in France and to characterise the antidepressant users with a short duration of treatment.
An observational retrospective cohort study was conducted in the community-dwelling population 18 year-old and over through claims databases of the public health insurance. A random sample of 34.663 outpatients who initiated an antidepressant treatment between the 1st January 2005 and the 31st December 2006 were selected. The dependent variable was the duration of the first episode of antidepressant treatment, categorised a priori in short duration [1-6 months[ versus long duration [6 months and more] according to guidelines. Characteristics independently associated with the treatment duration were investigated using logistic regressions.
Nearly two thirds of the individuals were females. Most patients were not on welfare. Three quarters of them did not present with chronic conditions. The duration of the antidepressant treatment complied with the international recommendations for only one patient of six. Adequate treatment duration was associated with being a female, being older, not being on welfare, presenting with a chronic condition and a treatment introduction by a psychiatrist or a hospital practitioner.
The recommendations concerning the duration of an antidepressant treatment are rarely respected in a real-life setting in France. Further analyses should be conducted to characterise the patterns of prescription according to antidepressant classes and associated treatments.
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.
We examine the metallicity trends in the Milky Way (MW) bulge – using APOGEE DR13 data – and explore their origin by comparing two N-body models of isolated galaxies which develop a bar and a boxy/peanut (b/p) bulge. Both models have been proposed as scenarios for reconciling a disc origin of the MW bulge with a negative vertical metallicity gradient. The first is a superposition of co-spatial disc populations, different scaleheights and metallicities (with flat gradients) where the thick, metal-poor populations contribute significantly to the stellar mass budget in the inner galaxy. The second model is a single disc with an initial steep radial metallicity gradient which gets mapped by the bar into the b/p bulge in such a way that the vertical metallicity gradient of the MW bulge is reproduced – as shown already in previous works in the literature. As we show here, the latter model does not reproduce the positive longitudinal metallicity gradient of the inner disc, nor the metal-poor innermost regions seen in the data. The model with co-spatial thin and thick disc populations reproduces all the aforementioned trends. We therefore see that it is possible to reconcile a (primarily) disc origin for the MW bulge with the observed trends in metallicity by mapping the inner thin and thick discs of the MW into a b/p.
Cryptosporidium is a protozoan parasite that causes the diarrhoeal disease, cryptosporidiosis. Although many species have been identified, the majority of human disease worldwide is caused by two species; Cryptosporidium parvum and Cryptosporidium hominis. In Australia, data from the National Notifiable Diseases Surveillance System (NNDSS) show that cryptosporidiosis outbreaks occur every few years. To better understand the transmission, trends and nature of cryptosporidiosis outbreaks in Western Australia, epidemiological and genomic data from three cryptosporidiosis outbreaks in 2003, 2007 and 2011 were reviewed. The 2007 outbreak was the largest (n = 607) compared with the outbreaks in 2003 (n = 404) and 2011 (n = 355). All three outbreaks appeared to have occurred predominantly in the urban metropolitan area (Perth), which reported the highest number of case notifications; increases in case notifications were also observed in rural and remote areas. Children aged 0–4 years and non-Aboriginal people comprised the majority of notifications in all outbreaks. However, in the 2003 and 2007 outbreaks, a higher proportion of cases from Aboriginal people was observed in the remote areas. Molecular data were only available for the 2007 (n = 126) and 2011 (n = 42) outbreaks, with C. hominis the main species identified in both outbreaks. Subtyping at the glycoprotein 60 (gp60) locus identified subtype IbA10G2 in 46.3% and 89.5% of C. hominis isolates typed, respectively, in the 2007 and 2011 outbreaks, with the IdA15G1 subtype was identified in 33.3% of C. hominis isolates typed in the 2007 outbreak. The clustering of cases with the IdA15G1 subtype in the remote areas suggests the occurrence of a concurrent outbreak in remote areas during the 2007 outbreak, which primarily affected Aboriginal people. Both the C. hominis IbA10G2 and IdA15G1 subtypes have been implicated in cryptosporidiosis outbreaks worldwide; its occurrence indicates that the mode of transmission in both the 2007 and 2011 outbreaks was anthroponotic. To better understand the epidemiology, sources and transmission of cryptosporidiosis in Australia, genotyping data should routinely be incorporated into national surveillance programmes.
We explore morphological, kinematic and chemical trends of boxy/peanut (b/p) bulges of Milky Way (MW)-type galaxies, to better understand the formation history of the MW’s bulge. We show, using N-body simulations with both a kinematically cold and a kinematically hot disc, that colder populations develop a more prominent bar and X-shaped peanut as compared to their hotter counterpart. Colder discs also exhibit lower line-of-sight velocities (when viewed edge-on) at the edges of the b/p compared to hot discs, in agreement with what is seen for the MW bulge. Furthermore, we explore an N-body model which has three co-spatial discs with metallicities which correspond to the stellar populations of the inner Milky Way, where the α-enhanced thick disc populations are massive and centrally concentrated. The metallicity trends seen in observations of the Bulge can be reproduced in the model without the need of adding any additional components, which hints to the disc origin of the MW’s bulge.
To explore the relation between bar formation and star formation in Milky Way-type galaxies quantitatively, we simulated gas-rich disk isolated galaxies. We find that the action of the stellar bar efficiently quenches star formation, reducing the star-formation rate by a factor of 10 in less than 1 Gyr. Analytical and self-consistent galaxy simulations with bars suggest that the action of the stellar bar increases the gas random motions within the co-rotation radius of the bar. Indeed, we detect an increase in the gas velocity dispersion at the end of the bar formation phase. The star formation efficiency decreases rapidly, and in all of our models, the bar quenches the star formation in the galaxy. The star-formation efficiency is much lower in simulated barred compared to unbarred galaxies and more rapid bar formation implies more rapid quenching.
Limiting the post-weaning intake of the young rabbit is known to improve its resistance to digestive disorders, whereas a degradation of its housing hygiene is assumed to have a negative impact on its health. This study aims at providing insights into the mechanism of digestive health preservation regarding both host (growth and immune response) and its symbiotic digestive microbiota. A 2×2 factorial design from weaning (day 28) to day 64 was set up: ad libitum intake or restricted intake at 70% of ad libitum, and high v. low hygiene of housing (n=105 per group). At day 36 and day 45, 15 animals/group were subcutaneously immunized with ovalbumin (OVA) to assess their specific immune response. Blood was sampled at 36, 45, 57 and 64 days of age to determine total and anti-OVA immunoglobulin type G (IgG) and haptoglobin levels. The cecal bacterial community was explored (18 per group) by 454 pyrosequencing of genes coding for the 16S ribosomal RNA, whereas cecal pH, NH3 and volatile fatty acid (VFA) concentrations were measured to characterize fermentative activity. A 30% reduction in feed intake reduced the growth by only 17% (P<0.001), and improved the feed conversion ratio by 15% (P<0.001), whereas the degradation of hygiene conditions slightly decreased the feed intake in ad libitum fed rabbits (−3.5%, P<0.02). As poor hygiene conditions did not affect weight gain, feed conversion was improved from day 42 (P<0.05). Restricted feeding led to a lower mortality between day 28 and day 40 (P=0.047), whereas degraded hygiene conditions decreased overall morbidity (7.8% v. 16.6%; P<0.01). Both a reduced intake and low hygiene conditions of housing affected microbiota composition and especially dominant genera belonging to the Ruminococcaceae family (P<0.01). Moreover, low hygiene was associated with a higher Ruminococcaceae/Lachnospiraceae ratio (3.7 v. 2.4; P<0.05). Cecal total VFA and pH were increased (+19%; P<0.001) and decreased (−0.1 pH unit; P<0.05), respectively, in feed-restricted rabbits. Neither specific anti-OVA IgG nor haptoglobin was affected by treatments. Total IgG concentrations were the highest in animals raised in poor hygiene conditions after 8 days of restriction, but decreased after 19 days of restriction in high hygiene conditions (−2.15%; P<0.05). In conclusion, the degradation of hygiene conditions failed to induce a systematic specific and inflammatory response in rabbit, but reduced morbidity instead. Our results suggest that the microbiota composition would be a helpful source of biomarkers of digestive health.
Recent CO surveys of star-forming galaxies (SFGs) at z ~ 2 have revolutionized our picture of massive galaxies. It is time to expand these studies toward the more common z ~ 2 SFGs with SFR < 40 M⊙ yr−1 and M* < 2.5 × 1010 M⊙. We have derived molecular gas, stars, and dust in 8 such lensed SFGs. They extend the LIR–L'CO(1-0) distribution of massive z>1 SFGs and increase the spread of the SFG star formation efficiency (SFE). A single star formation relation is found when combining all existing CO-detected galaxies. Our low-M* SFGs also reveal a SFE decrease with M* as found locally. A rise of the molecular gas fraction (fgas) with redshift is observed up to z ~ 1.6, but it severely flattens toward higher redshifts. We provide the first insight into the fgas upturn at the low-M* end 109.4 < M*/M⊙ < 1010 reaching fgas ~ 0.7, it is followed by a fgas decrease toward higher M*. Finally, we find a non-universal dust-to-gas ratio among local and high-redshift SFGs and starbursts with near-solar metallicities.
The properties of the host galaxies of quasi-stellar objects (QSOs) are essential for the understanding of the suspected coevolution of central supermassive black holes (BHs) and their host galaxies. In Busch et al. (2014), we present a study of 20 low-luminosity type-1 QSOs (LLQSO; Busch et al.2012) that have been selected from the Hamburg/ESO survey for bright UV-excess QSOs (z ≤ 0.06). Performing careful decomposition of deep near-infrared J,H,K images, we found that the observed sources do not follow published MBH – Lbulge relations for inactive galaxies, supporting similar results found for type-1 AGN in the optical. This can be explained by overluminous bulges with very young stellar populations or undermassive black holes that are observed in a phase of growth. We use 3d-spectroscopy in the optical and near-infrared as a powerful tool to analyze gas and stellar kinematics, determine gas masses, star formation rate, trace underlying stellar continuum, etc. (e.g., Smajić et al.2014) and thereby constrain possible evolution scenarios. The results will be interpreted in the context of galaxy evolution and particularly the still unknown role of the AGN in this process. Here, we show first results for HE 1029-1831.
We present ALMA cycle 0 observations of the luminous merger VV 114. One of the main goals is to investigate mechanisms of molecular line ratio enhancement. Regions with the high 12CO (1–0)/13CO (1–0) and 12CO (3–2)/12CO (1–0) is located at a central filamentary structure (∼6 kpc) in VV 114. The filament consists of the eastern nucleus and the overlap region, where the galaxy disks are colliding. We also investigate these molecular line ratios on the Kennicutt-Schmidt law. VV 114 fills a gap between the “starburst” sequence and the “normal disk” sequence, and regions with the high ratios show the high ΣSFR and ΣH2. We suggest that the high ratios in VV 114 are due to star-forming activities in the both progenitor's nuclei and the merger-induced overlap region.
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.
We study the stellar content of three galactic bulges with the high resolution gratings (R=7000) of the WiFeS integral field unit in order to better understand their formation and evolution. In all cases we find that at least 50% of the stellar mass already existed 12 Gyrs ago, more than currently predicted by simulations. A younger component (age between ∼1 to ∼8 Gyrs) is also prominent and its present day distribution seems to be much more affected by morphological structures, especially bars, than the older one. This in-depth analysis supports the notion of increasing complexity in bulges which cannot be achieved by mergers alone, but requires a non-negligible contribution from secular evolution.
We present the KMOS (K-band Multi-Object Spectrograph) Cluster and VIRIAL (VLT IRIFU Absorption Line) Guaranteed Time Observation (GTO) programs. KMOS provides 24 arms each feeding an integral field unit (14×14 spaxels of 0.2″ pixels) for IZ, YJ, H and K band near infrared (NIR) medium resolution spectroscopy (R ∼ 3500). Targets are selected from a 7.2′ diameter patrol field. Ultra-deep spectroscopy of ∼ 80 early-type cluster galaxies (∼ 20hr on source) and ∼ 200 (∼ 10hr on source) early-type field galaxies at 1 < z < 2 will dramatically improve the situation at z > 1 for which measurements of stellar velocity dispersions and absorption indices are limited to a few, often relatively young passively evolving galaxies (e.g. Bezanson 2013). In ESO Periods P92 and P93, 15 nights worth of data has been collected for KMOS-Clusters and 6 nights for VIRIAL: this will be supplemented with more data in upcoming semesters. All galaxies have multiband HST imaging including existing or upcoming WFC3 IR imaging, providing stellar mass maps and sizes. Combined with our dispersion measurements, this will allow us to examine the fundamental plane and the dynamical mass of a large sample of z > 1 galaxies for the first time, for both cluster and field galaxies.
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.
Here we present the first results from the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) which aims to investigate the physics of ∼140 radio-detected southern active Galaxies with z<0.02 through Integral Field Spectroscopy using the Wide Field Spectrograph (WiFeS). This instrument provides data cubes of the central 38×25 arc sec. of the target galaxies in the waveband 340–710nm with the unusually high resolution of R=7000 in the red (530–710nm), and R=3000 in the blue (340–560nm). These data provide the morphology, kinematics and the excitation structure of the extended narrow-line region, probe relationships with the black hole characteristics and the host galaxy, measures host galaxy abundance gradients and the determination of nuclear abundances from the HII regions. From photoionisation modelling, we may determine the shape of the ionising spectrum of the AGN, discover whether AGN metallicities differ from nuclear abundances determined from HII regions, and probe grain destruction in the vicinity of the AGN. Here we present some preliminary results and modelling of both Seyfert galaxies observed as part of the survey.
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.