Grain growth in the envelopes and disks of Class I protostars

We present new 3 mm ATCA data of two Class I Young Stellar Objects in the Ophiucus star forming region: Elias29 and WL12. For our analysis we compare them with archival 1.1 mm SMA data. In the (u,v) plane the two sources present a similar behavior: a nearly constant non-zero emission at long baselines, which suggests the presence of an unresolved component and an increase of the fluxes at short baselines, related to the presence of an extended envelope. Our data analysis leads to unusually low values of the spectral index $\alpha_{\rm 1.1-3mm}$, which may indicate that mm-sized dust grains have already formed both in the envelopes and in the disk-like structures at such early stages. To explore the possible scenarios for the interpretation of the sources we perform a radiative transfer modeling using a Monte Carlo code, in order to take into account possible deviations from the Rayleigh-Jeans and optically thin regimes. Comparison between the model outputs and the observations indicates that dust grains may form aggregates up to millimeter size already in the inner regions of the envelopes of Class I YSOs. Moreover, we conclude that the embedded disk-like structures in our two Class Is are probably very compact, in particular in the case of WL12, with outer radii down to tens of AU.Comment: 12 pages, 8 figures, Accepted for publication in A&

High-throughput proteogenomics of Ruegeria pomeroyi: seeding a better genomic annotation for the whole marine Roseobacter clade

<p>Abstract</p> <p>Background</p> <p>The structural and functional annotation of genomes is now heavily based on data obtained using automated pipeline systems. The key for an accurate structural annotation consists of blending similarities between closely related genomes with biochemical evidence of the genome interpretation. In this work we applied high-throughput proteogenomics to <it>Ruegeria pomeroyi</it>, a member of the <it>Roseobacter </it>clade, an abundant group of marine bacteria, as a seed for the annotation of the whole clade.</p> <p>Results</p> <p>A large dataset of peptides from <it>R. pomeroyi </it>was obtained after searching over 1.1 million MS/MS spectra against a six-frame translated genome database. We identified 2006 polypeptides, of which thirty-four were encoded by open reading frames (ORFs) that had not previously been annotated. From the pool of 'one-hit-wonders', <it>i.e</it>. those ORFs specified by only one peptide detected by tandem mass spectrometry, we could confirm the probable existence of five additional new genes after proving that the corresponding RNAs were transcribed. We also identified the most-N-terminal peptide of 486 polypeptides, of which sixty-four had originally been wrongly annotated.</p> <p>Conclusions</p> <p>By extending these re-annotations to the other thirty-six <it>Roseobacter </it>isolates sequenced to date (twenty different genera), we propose the correction of the assigned start codons of 1082 homologous genes in the clade. In addition, we also report the presence of novel genes within operons encoding determinants of the important tricarboxylic acid cycle, a feature that seems to be characteristic of some <it>Roseobacter </it>genomes. The detection of their corresponding products in large amounts raises the question of their function. Their discoveries point to a possible theory for protein evolution that will rely on high expression of orphans in bacteria: their putative poor efficiency could be counterbalanced by a higher level of expression. Our proteogenomic analysis will increase the reliability of the future annotation of marine bacterial genomes.</p

EFFECTS OF LOW ANTINUTRITIONAL FACTORS RAW FULL-FAT SOYBEAN ON BEEF CATTLE FEEDING. INFRA-VITAM PERFORMANCE

The aim of this trial was to evaluate the effects of different sources of soybean on the infra-vitam performance of fattening beef cattle. The animals (56 Limousine) were divided, according to BW (287±17 kg), in 4 experimental groups: LAFS (raw full-fat soybean low in antinutritional factors); SBM (soybean meal); TS (toasted full-fat soybean); NTS (non toasted full-fat soybean). The animals were fed a basal diet (TMR) (DM:59.5%; CP:9.3%DM; NDF:33.9%DM; starch:34.9%DM) supplemented as top dressing with different sources of soybeans in order to reach the same amount of additional CP (473 g/d). To obtain isoenergetic diets, calcium soap of palm fat (234 g/d) was also added to SBM group. Animals were weighed monthly, DM intake was calculated daily and two blood samplings were collected. No metabolic disorders or pathological events were observed during the experiment. The daily gains of the first 6 months were not significantly different among the 4 experimental groups (on the average 1.35 ± 0.25 kg/d). DM intake values in the same period were similar (8.57 ± 0.78 kg/d of DM). The soybean supplementation did not affect the metabolic parameters (calculated as differences between the sampling times) except for the *-glutamyl-transferase (P<0.01), the total plasma protein and globulin (P<0.05). The preliminary results of this experiment can indicate no significant effects of soybean antinutritional factors on the infra-vitam performances of beef cattle during the first fattening period

growth performance and behaviour of finishing beef cattle illegally treated with growth promoters

The study aimed at evaluating growth performance, feeding and social behaviour of finishing beef cattle treated with Dexamethasone per os alone or in association with Estradiol. Twenty-four French cross-bred beef bulls were allotted to 3 balanced treatment groups: Control (C); Dexamethasone (D) and Dexamethasone + Estradiol (D+E). All the bulls received the same diet and the experimental period lasted 43 days. All the productive traits and eating behaviour were similar among treatments. Bulls provided with D+E showed a prolonged rumination during the 8 h following diet distribution but this behaviour was partially performed in standing position, since lying was significantly reduced in both treated groups as compared to Control. However, difference in behaviour were too limited to be considered a reliable indicator of these illegal treatments

Constraining disk evolution prescriptions of planet population synthesis models with observed disk masses and accretion rates

While planets are commonly discovered around main-sequence stars, the processes leading to their formation are still far from being understood. Current planet population synthesis models, which aim to describe the planet formation process from the protoplanetary disk phase to the time exoplanets are observed, rely on prescriptions for the underlying properties of protoplanetary disks where planets form and evolve. The recent development in measuring disk masses and disk-star interaction properties, i.e., mass accretion rates, in large samples of young stellar objects demand a more careful comparison between the models and the data. We performed an initial critical assessment of the assumptions made by planet synthesis population models by looking at the relation between mass accretion rates and disk masses in the models and in the currently available data. We find that the currently used disk models predict mass accretion rate in line with what is measured, but with a much lower spread of values than observed. This difference is mainly because the models have a smaller spread of viscous timescales than what is needed to reproduce the observations. We also find an overabundance of weakly accreting disks in the models where giant planets have formed with respect to observations of typical disks. We suggest that either fewer giant planets have formed in reality or that the prescription for planet accretion predicts accretion on the planets that is too high. Finally, the comparison of the properties of transition disks with large cavities confirms that in many of these objects the observed accretion rates are higher than those predicted by the models. On the other hand, PDS70, a transition disk with two detected giant planets in the cavity, shows mass accretion rates well in line with model predictions

Characteristics of dairy farms in the North-Eastern part of Italy: rations, milk yield and nutrients excretion

This survey was aimed to evaluate the characteristics of dairy farms in the North- Eastern part of Po valley in terms of ration composition, milk yield and N and P excretions. Eightynine farms, with Italian Holstein Friesian cows, were selected in order to cover different situations in term of farm size and milk yield (MY). MY and quality were obtained from the national database of functional controls. Each farm was visited in order to collect information about ingredients and chemical composition of rations used. Farms were classified in four groups differing for dietary crude protein density (LCP15.3% DM) and for MY (LMY30 kg/d). N and P excretions were quantified by following a mass balance approach. Dietary crude protein content (CP) was not correlated to milk yield (MY) and quality. The estimated amounts of N excreted, discounted for 28% of N losses in atmosphere, were 78.5, 78.2, 87.2 and 89.1 kg/cow/year, and P excreted were 20.2, 18.6, 18.7 and 19.8 kg/cow/year for the LCPLMY, LCPHMY, HCPLMY, HCPHMY groups, respectively. On corn silage and cereals based rations, a dietary CP of 14.3% DM can support 31 kg MY/cow/day

Directly tracing the vertical stratification of molecules in protoplanetary disks

We aim to directly trace the vertical location of the emitting surface of multiple molecular tracers in protoplanetary disks. Our sample of disks includes Elias 2-27, WaOph 6 and the sources targeted by the MAPS ALMA Large Program. The set of molecules studied include CO isotopologues in various transitions, HCN, CN, H2CO, HCO+, C2H and c-C3H2. The vertical emitting region is determined directly from the channel maps, implementing accurate masking of the channel emission to recover the vertical location of the emission surface even at large radial distances from the star and for low-SNR lines. The vertical location of the emitting layer is obtained for 4-10 lines in each disk. IM Lup, HD163296 and MWC 480 12CO and 13CO show vertical modulations, which are coincident with dust gaps and kinematical perturbations. We also present estimates of the gas pressure scale height in the disks from the MAPS sample. Compared to physical-chemical models we find good agreement with the vertical location of CO isotopologues. In HD 163296 CN and HCN trace a similar intermediate layer, for the other disks, the UV flux tracers and the vertical profiles of HCN and C2H are lower than predicted in theoretical models. HCN and H2CO show a highly structured vertical profile, possibly indicative of different formation pathways. It is possible to trace the vertical locations of multiple molecular species that trace a wide variety of physical and chemical disk properties. The distribution of CO isotopologues are found at a wide range of vertical heights $z/r =$ 0.5-0.05. Other molecular lines are mostly found at $z/r \leq$0.15. The vertical layering of molecules is in agreement with theory in some systems, but not in all, therefore dedicated chemical-physical models are needed to further study and understand the emission surfaces.Comment: Accepted for publication in A&A. 29 pages, 28 figure