Habitat fragmentation and anthropogenic factors affect wildcat Felis silvestris silvestris occupancy and detectability on Mt Etna

Knowledge of patterns of occupancy is crucial for planning sound biological management and for identifying areas which require paramount conservation attention. The European wildcat Felis silvestris is an elusive carnivore and is classified as ‘least concern’ on the IUCN red list, but with a decreasing population trend in some areas. Sicily hosts a peculiar wildcat population, which deserves conservation and management actions, due to its isolation from the mainland. Patterns of occupancy for wildcats are unknown in Italy, and especially in Sicily. We aimed to identify which ecological drivers determined wildcat occurrence on Mt Etna and to provide conservation actions to promote the wildcats’ long-term survival in this peculiar environment. The genetic identity of the wildcat population was confirmed through a scat-collection which detected 22 different wildcat individuals. We analysed wildcat detections collected by 91 cameras using an occupancy frame work to assess which covariates influenced the detection (p) and the occupancy (ψ) estimates. We recorded 70 detections of the target species from 38 cameras within 3377 trap-days. Wildcat detection was positively influenced by the distance to the major paved roads and negatively affected by the presence of humans. Wildcat occupancy was positively associated with mixed forest and negatively influenced by pine forest, fragmentation of mixed forest and altitude. A spatially explicit predicted occupancy map, validated using an independent dataset of wildcat presence records, showed that higher occupancy estimates were scattered, mainly located on the north face and at lower altitude. Habitat fragmentation has been claimed as a significant threat for the wildcat and this is the first study that has ascertained this as a limiting factor for wildcat occurrence. Conservation actions should promote interconnectivity between areas with high predicted wildcat occupancy while minimising the loss of habitat

Record of a 10-year old European Wildcat Felis silvestris silvestris Schreber, 1777 (Mammalia: Carnivora: Felidae) from Mt. Etna, Sicily, Italy

We recaptured the Wildcat after nine years, hence we think that 10 years is the minimum reasonable age estimation for this individual. This age estimate still lies at the lower range when compared to ages of captive Wildcats ranging from 12–16 year

Deep near-infrared luminosity function of a cluster of galaxies at z=0.3

The deep near-infrared luminosity function of AC118, a cluster of galaxies at z=0.3, is presented. AC118 is a bimodal cluster, as evidenced both by our near-infrared images of lensed galaxies, by public X-ray Rosat images and by the spatial distribution of bright galaxies. Taking advantage of the extension and depth of our data, which sample an almost unexplored region in the depth vs. observed area diagram, we derive the luminosity function (LF), down to the dwarf regime (M*+5), computed in several cluster portions. The overall LF, computed on a 2.66 Mpc2 areas (H_0=50 km/s/Mpc), has an intermediate slope (alpha=-1.2). However, the LF parameters depend on the surveyed cluster region: the central concentration has 2.6^{+5.1}_{-1.7} times more bright galaxies and 5.3^{+7.2}_{-2.3} times less dwarfs per typical galaxy than the outer region, which includes galaxies at an average projected distance of ~580 kpc (errors are quoted at the 99.9 % confidence level). The LF in the secondary AC118 clump is intermediate between the central and outer one. In other words, the near-infrared AC118 LF steepens going from high to low density regions. At an average clustercentric distance of ~580 kpc, the AC118 LF is statistically indistinguishable from the LF of field galaxies at similar redshift, thus suggesting that the hostile cluster environment plays a minor role in shaping the LF at large clustercentric distances, while it strongly affects the LF at higher galaxy density.Comment: ApJ, in press. The whole paper with all high resolution images is available at http://www.na.astro.it/~andreon/listapub.htm

Numerical study of a non-equilibrium interface model

We have carried out extensive computer simulations of one-dimensional models related to the low noise (solid-on-solid) non-equilibrium interface of a two dimensional anchored Toom model with unbiased and biased noise. For the unbiased case the computed fluctuations of the interface in this limit provide new numerical evidence for the logarithmic correction to the subnormal L^(1/2) variance which was predicted by the dynamic renormalization group calculations on the modified Edwards-Wilkinson equation. In the biased case the simulations are in close quantitative agreement with the predictions of the Collective Variable Approximation (CVA), which gives the same L^(2/3) behavior of the variance as the KPZ equation.Comment: 15 pages revtex, 4 Postscript Figure

K-band luminosity (mass) segregation in AC118 at z=0.31

Using new observations of the galaxy cluster A118 at intermediate redshift (z=0.31) in the Ks band, we were able to detect the cluster from the center to half the Abell radius (1.5 Mpc, Ho=50 km/s/Mpc) and possibly to 2.0 Mpc. The analysis of both the spatial distribution of galaxies of various luminosities and of the luminosity function (LF) of galaxies in different cluster locations strongly confirms and extends to larger clustercentric radii the luminosity segregation found in a previous analysis of this cluster restricted to a smaller cluster area: there is an excess of bright galaxies in the cluster core (inside 250 Kpc) or a deficit of dwarfs in the remain part of the cluster. Outside the cluster core and as far as 1.5 or even 2 Mpc, the giant-to-dwarf ratio is constant. Because of the luminosity segregation, the LF of the AC118 shows a larger number of bright galaxies per unit dwarf in the core than in other cluster locations. All non-core LFs, computed at several cluster locations, are compatible each other. These results hold both including or excluding the galaxies located in an overdensity found in the far South of AC118 and in the second clump in galaxy density at the cluster North-West. Since the near-infrared emission is a good tracer of the stellar mass, we interpret the segregation found as a mass segregation.Comment: A&A in pres

Properties of mm galaxies: Constraints from K-band blank fields

We have used the IRAM Plateau de Bure mm interferometer to locate with subarcsecond accuracy the dust emission of three of the brightest 1.2mm sources in the NTT Deep Field (NDF) selected from our 1.2mm MAMBO survey at the IRAM 30m telescope. We combine these results with deep B to K imaging and VLA interferometry. Strikingly, none of the three accurately located mm galaxies MMJ120546-0741.5, MMJ120539-0745.4, and MMJ120517-0743.1 has a K-band counterpart down to the faint limit of K>21.9. This implies that these three galaxies are either extremely obscured and/or are at very high redshifts (z>~4). We combine our results with literature data for 11 more (sub)mm galaxies that are identified with similar reliability. In terms of their K-band properties, the sample divides into three roughly equal groups: (i) undetected to K~22, (ii) detected in the near-infrared but not the optical and (iii) detected in the optical with the possibility of optical follow-up spectroscopy. We find a trend in this sample between near-infrared to submm and submm to radio spectral indices, which in comparison to spectral energy distributions (SEDs) of low redshift infrared luminous galaxies suggests that the most plausible primary factor causing the extreme near-infrared faintness of our objects is their high redshift. We show that the near-infrared to radio SEDs of the sample are inconsistent with SEDs that resemble local far-infrared cool galaxies with moderate luminosities, which were proposed in some models of the submm sky. We briefly discuss the implications of the results for our understanding of galaxy formation.Comment: aastex, 5 figures. Accepted by Ap

Angle of Repose and Angle of Marginal Stability: Molecular Dyanmics of Granular Particles

We present an implementation of realistic static friction in molecular dynamics (MD) simulations of granular particles. In our model, to break contacts between two particles, one has to apply a finite amount of force, determined by the Coulomb criterion. Using a two dimensional model, we show that piles generated by avalanches have a {\it finite} angle of repose $\theta_R$ (finite slopes). Furthermore, these piles are stable under tilting by an angle smaller than a non-zero tilting angle $\theta_T$, showing that $\theta_R$ is different from the angle of marginal stability $\theta_{MS}$, which is the maximum angle of stable piles. These measured angles are compared to a theoretical approximation. We also measure $\theta_{MS}$ by continuously adding particles on the top of a stable pile.Comment: 14 pages, Plain Te

2MASS J03105986+1648155AB - A new binary at the L/T transition

The transition from the L to the T spectral type of brown dwarfs is marked by a very rapid transition phase, remarkable brightening in the J-band and a higher binary frequency. Despite being an active area of inquiry, this transition regime still remains one of the most poorly understood phases of brown dwarf evolution. We resolved the L dwarf 2MASS J03105986+1648155 for the first time into two almost equally bright components straddling the L/T transition. Since such a co-eval system with common age and composition provides crucial information of this special transition phase, we monitored the system over 3 years to derive first orbital parameters and dynamical mass estimates, as well as a spectral type determination. We obtained resolved high angular resolution, near-IR images with HST and the adaptive optics instrument NACO at the VLT including the laser guide star system PARSEC. Based on two epochs of astrometric data we derive a minimum semi-major axis of 5.2 +- 0.8 AU. The assumption of a face-on circular orbit yields an orbital period of 72 +- 4 years and a total system mass of 30-60 Mjup. This places the masses of the individual components of the system at the lower end of the mass regime of brown dwarfs. The achieved photometry allowed a first spectral type determination of L9 +- 1 for each component. In addition, this seems to be only the fifth resolved L/T transition binary with a flux reversal. While ultimate explanations for this effect are still owing, the 2MASS J03105986+1648155 system adds an important benchmark object for improving our understanding of this remarkable evolutionary phase of brown dwarfs. Additionally, the observational results of 2MASS J03105986+1648155 AB derived with the new PARSEC AO system at the VLT show the importance of this technical capability. The updated AO system allows us to significantly extend the sample of brown dwarfs observable with high-resolution from the ground and hence to reveal more of their physical properties.Comment: 6 pages, 2 figures, 3 tables, accepted for publication by A&

ESO Imaging Survey: infrared observations of CDF-S and HDF-S

This paper presents infrared data obtained from observations carried out at the ESO 3.5m New Technology Telescope (NTT) of the Hubble Deep Field South (HDF-S) and the Chandra Deep Field South (CDF-S). These data were taken as part of the ESO Imaging Survey (EIS) program, a public survey conducted by ESO to promote follow-up observations with the VLT. In the HDF-S field the infrared observations cover an area of ~53 square arcmin, encompassing the HST WFPC2 and STIS fields, in the JHKs passbands. The seeing measured in the final stacked images ranges from 0.79" to 1.22" and the median limiting magnitudes (AB system, 2" aperture, 5sigma detection limit) are J_AB~23.0, H_AB~22.8 and K_AB~23.0 mag. Less complete data are also available in JKs for the adjacent HST NICMOS field. For CDF-S, the infrared observations cover a total area of \~100 square arcmin, reaching median limiting magnitudes (as defined above) of J_AB~23.6 and K_AB~22.7 mag. For one CDF-S field H-band data are also available. This paper describes the observations and presents the results of new reductions carried out entirely through the un-supervised, high-throughput EIS Data Reduction System and its associated EIS/MVM C++-based image processing library developed, over the past 5 years, by the EIS project and now publicly available. The paper also presents source catalogs extracted from the final co-added images which are used to evaluate the scientific quality of the survey products, and hence the performance of the software. This is done comparing the results obtained in the present work with those obtained by other authors from independent data and/or reductions carried out with different software packages and techniques. The final science-grade catalogs and co-added images are available at CDS.Comment: Accepted for publication in A&A, 13 pages, 12 figures; a full resolution version of the paper is available from http://www.astro.ku.dk/~lisbeth/eisdata/papers/4528.pdf ; related catalogs and images are available through http://www.astro.ku.dk/~lisbeth/eisdata

Probiotic Bacillus subtilis 29,784 improved weight gain and enhanced gut health status of broilers under necrotic enteritis condition

The study investigated the benefit of a Bacillus subtilis probiotic (Bs 29,784) in necrotic enteritis (NE)-challenged broilers. Four treatments were performed with 312 male day-old Ross 308 reared in floor pens from day 0 to day 35: 2 groups fed control diet without or with NE challenge (CtrlNC and CtrlNE); 2 groups fed probiotic and antibiotic supplements in the control diet with NE challenge (ProNE and AntNE). Necrotic enteritis challenge procedures commenced with inoculation of Eimeria spp 1 mL/bird per os at day 9 and Clostridium perfringens EHE-NE18 (approximately 108 cfu/mL) 1 mL/bird per os at day 14 and day 15. Performance parameters were measured on day 16 and day 35. Lesion, cecal microbiota, and jejunal gene expression were analyzed on day 16. Necrotic enteritis challenge significantly suppressed the performance parameters compared with CtrlNC: 27% weight gain reduction, 11 points feed conversion ratio (FCR) increase at day 16, and 12% weight gain reduction, 5-point FCR increase at day 35. By day 35, ProNE and AntNE treatments enabled significantly higher weight gain (4 and 9%, respectively) than CtrlNE. Compared with CtlrNE and contrary to AntNE, ProNE treatment exhibited upregulation of genes coding for tight junctions proteins (CLDN1, JAM2, TJP1), cytokines (IL12, interferon gamma, TGFβ), and Toll-like receptors (TLR5, TLR21) suggesting enhanced immunity and intestinal integrity. 16S NGS analysis of cecal microbiota at day 16 showed a decreased alpha diversity in challenged groups. Principal component analysis of operational taxonomic unit (OTU) abundance revealed that ProNE and AntNE grouped closely while both distantly from CtrlNC and CtrlNE, which were separately grouped, indicating the similar effects of ProNE and AntNE on the OTU diversity that were however different from both CtrlNC and CtrlNE. Microbiota analysis revealed an increase of genera Faecalibacterium, Oscillospira, and Butyricicoccus; and a decrease of genera Ruminococcus, Lactobacillus, and Bacteroides; and an increase of the Firmicutes-to-Bacteroidetes ratio in ProNE and AntNE groups compared with the CtlrNE group. It is concluded that Bs 29,784 may enable improved health of broiler chickens under NE conditions thus performance implications