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One of the most prominent features of galaxy clusters is the presence of a dominant population of massive ellipticals in their cores. Stellar archaeology suggests that these gigantic beasts assembled most of their stars in the early Universe via starbursts. However, the role of dense environments and their detailed physical mechanisms in triggering starburst activities remain unknown. Here we report spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) observations of the CO J & x2004;=& x2004;3-2 emission line, with a resolution of about 2.5 kpc, toward a forming galaxy cluster core with starburst galaxies at z & x2004;=& x2004;2.51. In contrast to starburst galaxies in the field often associated with galaxy mergers or highly turbulent gaseous disks, our observations show that the two starbursts in the cluster exhibit dynamically cold (rotation-dominated) gas-rich disks. Their gas disks have extremely low velocity dispersion (sigma(0)& x2004;similar to & x2004;20-30 km s(-1)), which is three times lower than their field counterparts at similar redshifts. The high gas fraction and suppressed velocity dispersion yield gravitationally unstable gas disks, which enables highly efficient star formation. The suppressed velocity dispersion, likely induced by the accretion of corotating and coplanar cold gas, might serve as an essential avenue to trigger starbursts in massive halos at high redshifts.

We present the results of an integral field spectroscopy survey of a sample of dusty (ultra) luminous infrared galaxies (U/LIRGs) at 2 < z < 2.5 using KMOS on the Very Large Telescope. The sample has been drawn from Herschel deep field surveys and benefits from ancillary multiwavelength data. Our goal is to investigate the physical characteristics, kinematics, and the drivers of star formation in the galaxies whose contribution dominates the peak of the cosmic star formation density. Two-thirds of the sample are main-sequence galaxies in contrast to the starburst nature of local U/LIRGs. Our kinematic study, unique in its focus on z ∼ 2 dusty star-forming galaxies, uses the H α emission line to find that ∼40 per cent appear to be isolated discs based on the ratio of rotational velocity to the velocity dispersion, suggesting steady-state mechanisms are sufficient to power the large star formation rates (SFRs). The ratio of obscured to unobscured star formation indicates the sample of galaxies experiences less dust obscuration compared to intermediate and local counterparts, while also hosting cooler dust than local U/LIRGs. In addition to H α we detect [N II] 6583 Å in our targets and show the gas-phase metallicities do not exhibit the metal deficiency of local U/LIRGs. These results indicate that, despite their extreme IR luminosity, the underlying mechanisms driving the massive SFRs found at cosmic noon are due to scaled up disc galaxies as opposed to mergers. We want to thank the anonymous referee for their insightful comments and suggestions that improved the quality of this paper. The analysis in this paper is based on observations made with ESO Telescopes at the La Silla Paranal Observatory under run IDs: 092.B0769(A) and 097.B-0186(A). D.R., I.G.-B., and K.G. acknowledge support from STFC through grant ST/S000488/1. G.E.M. acknowledges the Villum Fonden research grant 13160 `Gas to stars, stars to dust: tracing star formation across cosmic time' and the Cosmic Dawn Center of Excellence funded by the Danish National Research Foundation under the grant No. 140. N.T. acknowledges support from STFC through grants ST/N002717/1 and ST/S001409/1. M.P.S. acknowledges support from the Comunidad de Madrid through Atracci ' on de Talento Investigador Grant 2018-T1/TIC-11035. Peerreview

This paper is the second of a series that tackles the properties of molecular gas in galaxies residing in clusters and their related large-scale structures. Out of 21 targeted fields, 19 galaxies were detected in CO(3-2) with the Atacama Large Millimeter Array (ALMA), including two detections within a single field. These galaxies are either bona fide members of the CL1301.7$-$1139 cluster ($z=0.4828$, $\sigma_{cl}=681$ km s$^{-1}$), or located within $\sim 7 \times R_{200}$, its virial radius. They have been selected to sample the range of photometric local densities around CL1301.7$-$1139, with stellar masses above log($M_{\rm star}$) = 10, and to be located in the blue clump of star-forming galaxies derived from the $u$, $g$, and $i$ photometric bands. Unlike previous works, our sample selection does not impose a minimum star formation rate or detection in the far-infrared. As such and as much as possible, it delivers an unbiased view of the gas content of normal star-forming galaxies at $z \sim 0.5$. Our study highlights the variety of paths to star formation quenching, and most likely the variety of physical properties (i.e. temperature, density) of the corresponding galaxy's cold molecular gas. Just as in the case of CL1411.1$-$1148, although to a smaller extent, we identify a number of galaxies with lower gas fraction than classically found in other surveys. These galaxies can still be on the star-forming main sequence. When these galaxies are not inside the cluster virialised region, we provide hints that they are linked to their infall regions within $\sim 4 \times R_{200}$., Comment: 15 pages, 11 figures, accepted for publication in A&A. arXiv admin note: text overlap with arXiv:2012.09592

Nowadays the trend toward the use of transportation technologies which are clean and less dependent on fossil fuel is highly increased. That is because of the fast depletion of oil reserves in the world, on the other hand the growth of developing nations into industrialized one’s will increase the demand on the energy sector , in which transportation occupy a large percent of it. This increase of transportation sector will affect the environment as a result of greenhouse gases. In this paper the use of several types of clean energy vehicles is demonstrated compared with classical internal combustion engine one’s, with statistical demonstration and the energy conversion chain, also the impact of hybrid vehicles on the petroleum reserves and consumption rates will be discussed using some mathematical equations.

In Meidt et al. (2018), we showed that gas kinematics on the scale of individual molecular clouds are not dominated by self-gravity but also track a component that originates with orbital motion in the potential of the host galaxy. This agrees with observed cloud line widths, which show systematic variations from virial motions with environment, pointing at the influence of the galaxy potential. In this paper, we hypothesize that these motions act to slow down the collapse of gas and so help regulate star formation. Extending the results of Meidt et al. (2018), we derive a dynamical collapse timescale that approaches the free-fall time only once the gas has fully decoupled from the galactic potential. Using this timescale we make predictions for how the fraction of free-falling, strongly self-gravitating gas varies throughout the disks of star-forming galaxies. We also use this collapse timescale to predict variations in the molecular gas star formation efficiency, which is lowered from a maximum, feedback-regulated level in the presence of strong coupling to the galactic potential. Our model implies that gas can only decouple from the galaxy to collapse and efficiently form stars deep within clouds. We show that this naturally explains the observed drop in star formation rate per unit gas mass in the Milky Way's CMZ and other galaxy centers. The model for a galactic bottleneck to star formation also agrees well with resolved observations of dense gas and star formation in galaxy disks and the properties of local clouds., Comment: Accepted for publication in ApJ, 32 pages, 11 figures

We use new ALMA observations to investigate the connection between dense gas fraction, star formation rate, and local environment across the inner region of four local galaxies showing a wide range of molecular gas depletion times. We map HCN (1-0), HCO$^+$ (1-0), CS (2-1), $^{13}$CO (1-0), and C$^{18}$O (1-0) across the inner few kpc of each target. We combine these data with short spacing information from the IRAM large program EMPIRE, archival CO maps, tracers of stellar structure and recent star formation, and recent HCN surveys by Bigiel et al. and Usero et al. We test the degree to which changes in the dense gas fraction drive changes in the SFR. $I_{HCN}/I_{CO}$ (tracing the dense gas fraction) correlates strongly with $I_{CO}$ (tracing molecular gas surface density), stellar surface density, and dynamical equilibrium pressure, $P_{DE}$. Therefore, $I_{HCN}/I_{CO}$ becomes very low and HCN becomes very faint at large galactocentric radii, where ratios as low as $I_{HCN}/I_{CO} \sim 0.01$ become common. The apparent ability of dense gas to form stars, $\Sigma_{SFR}/\Sigma_{dense}$ (where $\Sigma_{dense}$ is traced by the HCN intensity and the star formation rate is traced by a combination of H$\alpha$ and 24$\mu$m emission), also depends on environment. $\Sigma_{SFR}/\Sigma_{dense}$ decreases in regions of high gas surface density, high stellar surface density, and high $P_{DE}$. Statistically, these correlations between environment and both $\Sigma_{SFR}/\Sigma_{dense}$ and $I_{HCN}/I_{CO}$ are stronger than that between apparent dense gas fraction ($I_{HCN}/I_{CO}$) and the apparent molecular gas star formation efficiency $\Sigma_{SFR}/\Sigma_{mol}$. We show that these results are not specific to HCN., Comment: 31 pages, 13 figures, accepted for publication in The Astrophysical Journal, email for access to data table before publication

The processes regulating star formation in galaxies are thought to act across a hierarchy of spatial scales. To connect extragalactic star formation relations from global and kpc-scale measurements to recent cloud-scale resolution studies, we have developed a simple, robust method that quantifies the scale dependence of the relative spatial distributions of molecular gas and recent star formation. In this paper, we apply this method to eight galaxies with roughly 1 arcsec resolution molecular gas imaging from the PHANGS-ALMA and PAWS surveys that have matched resolution, high quality narrowband Halpha imaging. At a common scale of 140pc, our massive (log(Mstar/Msun)=9.3-10.7), normally star-forming (SFR/Msun/yr=0.3-5.9) galaxies exhibit a significant reservoir of quiescent molecular gas not associated with star formation as traced by Halpha emission. Galactic structures act as backbones for both molecular and HII region distributions. As we degrade the spatial resolution, the quiescent molecular gas disappears, with the most rapid changes occurring for resolutions up to about 0.5kpc. As the resolution becomes poorer, the morphological features become indistinct for spatial scales larger than about 1kpc. The method is a promising tool to search for relationships between the quiescent or star-forming molecular reservoir and galaxy properties, but requires a larger sample size to identify robust correlations between the star-forming molecular gas fraction and global galaxy parameters., Accepted to ApJ, 29 pages with 9 figures and 7 tables

U veterinarskoj medicini u uporabi je veliki broj antimikrobnih tvari i antiparazitika te ih dijelimo na antibakterijske, antifungalne, antiviralne i antiparazitske lijekove. Samo su neke od tih tvari dopuštene za uporabu u profilaktičke svrhe pri uzgoju životinja čiji se proizvodi na tržište stavljaju kao hrana. Usprkos tome, u hrani životinjskog podrijetla česta je pojava rezidua veterinarskih lijekova. U te lijekove ubrajamo i kokcidiostatike čija je primjena raširena u peradarstvu, kako u profilaksi, tako i u terapiji. Kokcidioza je parazitska bolest prouzročena jednostaničnom protozoonom roda Eimeria. Zbog velikog reproduktivnog potencijala, preživljavanja sporuliranih oocisti u stelji te različite patogenosti, kokcidioza predstavlja najznačajniju bolest intenzivne proizvodnje peradi. Iz navedenog je jasno da današnja intenzivna proizvodnja peradi nije moguća bez kontrole kokcidija kokcidiostaticima, kokcidiocidima ili cijepljenjem. Kokcidiostatici, tj. polieterskih ionofori, se razlikuju od ostalih antimikrobnih tvari. Nazivaju ih još i transportnim antibioticima jer djeluju na način da se inkorporiraju u membranu stanice tvoreći svojevrsne ionske tunele te prouzroče gubitak iona i oštećenja stanice. Kokcidiostatici se često detektiraju u hrani za neciljane skupine životinja, kao posljedica onečišćenja tijekom proizvodnje. U literaturi nedostaju podatci o raspodjeli kokcidiostatika u organizmu životinje nakon primjene kao i podatci o kinetici njegovog izlučivanja iz organizma. Kokoši nesilice su najčešća neciljna skupina koja je izložena kokcidiostaticima. Ovaj pregledni rad daje sažetak znanstvenih pokusa u kojima su istraženi kokcidiostatici i njihova akumulacija i vrijeme zadržavanja u organizmu. Afinitet vezanja veterinarskih lijekova u tkivu nakon njihove primjene ovise o njihovim kemijskim svojstvima kao što su: molarna masa, lipofilnost, konstanta disocijacije i afinitet vezanja na proteine. Pregledom znanstvenih istraživanja o zastupljenosti kokcidiostatika u jajima može se zaključiti da ukoliko tvari dominiraju u žumanjku jajeta kao rezidue, velika je vjerojatnost da će vrijeme zadržavanja biti i više od 10 dana. To se može protumačiti činjenicom da razvojni proces žumanjka započinje nekoliko dana prije nego li će jaje biti snijeto i to u jetri gdje nastaju prvi prekursori žumanjka. U usporedbi s tim, bjelanjak se razvija svega nekoliko sati prije nesenja jajeta. Stoga na učestalost pojave zaostataka rezidua u neciljnim tkivima ne utječe samo stupanj kontaminiranosti krmne smjese za neciljne skupine, nego i farmakokinetička svojstva i stupanj akumulacije svakog pojedinog kokcidiostatika., Antimicrobial agents are widely applied in human and veterinary medicine, including antibacterial, antifungal, antiviral and antiparasitic drugs. Few of these substances are approved for use in prophylaxis during intensive breeding of animals whose products are targeted for the market. Despite this, veterinary drug residues are often present in food of animal origin. Coccidiostats are also classified into this group of drugs that are highly present in poultry-farming for prophylaxis and therapy. Coccidiosis is a parasitic disease caused by the unicellular protozoon of the genus Eimeria. Due to its great reproductive potential, survival of sporulated oocysts in soil and various pathogenicities, coccidiosis is the most significant disease of intensive poultry production. From this, it is evident that today’s intensive poultry production would not be possible without the control of coccidiosis by coccidiostats or vaccination. Coccidiostats, i.e. polyether ionophores, differ from other antimicrobial substances. They are specified as transport antibiotics as they act by incorporation into the cell membrane through the formation of an ionic tunnel, causing ion loss and cell damage. Coccidiostats are often detected in feed for non-target animals as a result of cross- contamination during industrial production. Studies on the occurrence of coccidiostats in animal tissues or elimination time from theorganismareratherscarce.Hensarethe most common non-target group exposed to coccidiostats. This is an overview of the scientific experiments examining coccidostats and their accumulations and depletion times. The affinity of the compound to accumulate in tissues after implementation depends on its chemical properties, such as molar mass, lipophilicity, dissociation constant and protein binding affinity. In summarising the current literature on the presence of coccidiostats in eggs, it can be concluded that if the substances dominate in egg yolk as residuals, the depletion time is likely to be longer than 10 days. This can be interpreted by the fact that egg yolk development begins a few days prior to hatching, e.g. in the liver, where the first egg yolk precursors are formed. In comparison, egg whites develop only hours before hatching. Therefore, the frequency of residues occurring in non-target tissues is dependent not only on the degree of contamination of the feed mixture for non-target groups, but also on the pharmacokinetic properties and the rate of accumulation of each individual coccidiostat.

One of the key goals of the Bluedisk survey is to characterize the impact of gas accretion in disc galaxies in the context of galaxy evolution. It contains 50 disc galaxies in the stellar mass range 10^10-10^11 Msun, of which half are bluer and more HI-rich galaxies than their HI-normal (control) counterparts. In this paper, we investigate how ongoing disc growth affects the molecular gas distribution and the star-formation efficiency in these galaxies. We present 12CO observations from the IRAM 30-m telescope in 26 galaxies of the Bluedisk survey. We compare the amount and spatial distribution of the molecular gas to key quantities such as atomic gas, stellar mass and surface density, star-formation rate and metallicity. We analyse the star-formation rate per unit gas (SFR/HI and SFR/H2) and relate all those parameters to general galaxy properties (HI-rich/control disc, morphology, etc.). We find that the HI-rich galaxies have similar H2 masses as the control galaxies. In their centres, HI-rich galaxies have lower H2/HI ratios and marginally shorter molecular gas depletion times. However, the main differences between the two samples occur in the outer parts of the discs, with the HI-rich galaxies having slightly smaller CO discs (relative to the optical radius R25) and steeper CO and metallicity gradients than the control galaxies. The ongoing accretion of HI at large radii has thus not led to an appreciable growth of the CO discs in our sample. Based on depletion times, we estimate that this gas will contribute to star formation on time-scales of at least 5 Gyr., Accepted for publication in MNRAS

We develop a method to characterize the location as well as the time of approach of optimal steady states in single-state, infinite-horizon, autonomous models. The method is based on a simple function of the state variable which is defined in terms of the model's primitives. The actual implementation does not require to solve the underlying dynamic optimization problem (which often does not admit a closed-form solution). Applying the method to a generic class of resource management problems, we show how it identifies the set of candidate steady states and determines, for each steady state, whether the corresponding approach time is finite or infinite.

O objetivo deste trabalho foi validar um método para determinação de resíduos de oxitetraciclina (OTC) em camarões, por meio de cromatografia líquida de alta eficiência, e avaliar, pelo método validado, a depleção de resíduos de OTC em camarões in vivo. Para a validação, foram utilizados camarões isentos de OTC e camarões adicionados de OTC in vitro. Foram estabelecidos: seletividade, tempo de retenção, linearidade (coeficiente de correlação), faixa de trabalho, recuperação relativa, limites de detecção e quantificação do método (LDM e LQM, respectivamente) e repetibilidade. Para o experimento in vivo, rações com 200, 400 e 500 μg g-1 de OTC foram administradas aos camarões durante 14 dias. Foi avaliada a concentração do resíduo desse antibiótico no músculo e na carapaça até 22 dias após a suspensão da droga. O coeficiente de correlação linear foi de 0,9997 para o extrato fortificado da matriz, na faixa de trabalho de 0,02 a 0,4 μg g-1; a recuperação foi de 106±17,1% e os LDM e LQM foram de 0,006 e 0,019 μg g-1, respectivamente. O tempo de residência da droga na carapaça dos animais (de 10 a 13 dias) foi maior em comparação ao tempo de residência no músculo (5 dias). This work aimed at validating a method for the determination of oxytetracycline (OTC) residues in shrimp by means of high performance liquid chromatography (HPLC), and at evaluating the OTC residue depletion in shrimps in vivo using the validated method. The shrimp used for validation were either not submitted or submitted to in vitro OTC addition. Selectivity, retention time, linearity (correlation coefficient), work range, relative recovery, detection and method quantification limits and repeatability were determined. For the in vivo experiment, shrimp were fed with feed medicated with OTC at 200, 400 and 500 μg g-1 for 14 days. Oxytetracycline residue concentration in the animals' muscle and carapace was assessed for up to 22 days after stopping medication. The results obtained were: 0.9997 linear correlation coefficient for the fortified matrix extract within a work range of 0.02-0.4 μg g-1, 106±17.1% recovery and 0.006 and 0.019 μg g-1 detection and quantification limits, respectively. A greater OTC residence time was observed in the carapace (10 to 13 days) when compared to the muscle (5 days).

We compare molecular gas traced by 12CO(2-1) maps from the HERACLES survey, with tracers of the recent star formation rate (SFR) across 30 nearby disk galaxies. We demonstrate a first-order linear correspondence between Sig_mol and Sig_SFR but also find important second-order systematic variations in the apparent molecular gas depletion time, t_dep^mol = Sig_mol / Sig_SFR. At our 1 kpc common resolution, CO correlates closely with many tracers of the recent SFR. Weighting each line of sight equally and using a fixed, Milky Way alpha_CO, our data yield a molecular gas depletion time, t_dep^mol=Sig_mol/Sig_SFR ~ 2.2 Gyr with 0.3 dex scatter, in good agreement with literature data. We apply a forward-modeling approach to constrain the power-law index, N, that relates the SFR surface density and the molecular gas surface density and find N=1+/-0.15 for our full data set with some variation from galaxy to galaxy. However, we caution that a power law treatment oversimplifies the topic given that we observe correlations between t_dep^mol and other local and global quantities. The strongest of these are a decreased t_dep^mol in low-mass, low-metallicity galaxies and a correlation of the kpc-scale t_dep^mol with dust-to-gas ratio, D/G. These correlations can be explained by a CO-to-H2 conversion factor that depends on D/G in the theoretically expected way. This is not a unique interpretation, but external evidence of conversion factor variations makes it a conservative one. After applying a D/G-dependent alpha_CO, some weak correlations between t_dep^mol and local conditions persist. In particular, we observe lower t_dep^mol and enhanced CO excitation associated with some nuclear gas concentrations. These appear to reflect real enhancements in the SFR/H2 and t_dep appears multivalued at fixed Sig_mol, supporting the the idea of "disk" and "starburst" modes driven by environmental factors., 39 pages (incl. 10 page appendix), 19 figures, figures degraded for astro-ph. Until publication a higher resolution version available at http://www.cv.nrao.edu/~aleroy/heracles_sfco.pdf - we suggest that one

We identify stellar structures in the PHANGS sample of 74 nearby galaxies and construct morphological masks of sub-galactic environments based on Spitzer 3.6 micron images. At the simplest level, we distinguish centres, bars, spiral arms, interarm and discs without strong spirals. Slightly more sophisticated masks include rings and lenses, publicly released but not explicitly used in this paper. We examine trends using PHANGS-ALMA CO(2-1) intensity maps and tracers of star formation. The interarm regions and discs without strong spirals dominate in area, whereas molecular gas and star formation are quite evenly distributed among the five basic environments. We reproduce the molecular Kennicutt-Schmidt relation with a slope compatible with unity within the uncertainties, without significant slope differences among environments. In contrast to early studies, we find that bars are not always deserts devoid of gas and star formation, but instead they show large diversity. Similarly, spiral arms do not account for most of the gas and star formation in disc galaxies, and they do not have shorter depletion times than the interarm regions. Spiral arms accumulate gas and star formation, without systematically boosting the star formation efficiency. Centres harbour remarkably high surface densities and on average shorter depletion times than other environments. Centres of barred galaxies show higher surface densities and wider distributions compared to the outer disc; yet, depletion times are similar to unbarred galaxies, suggesting highly intermittent periods of star formation when bars episodically drive gas inflow, without enhancing the central star formation efficiency permanently. In conclusion, we provide quantitative evidence that stellar structures in galaxies strongly affect the organisation of molecular gas and star formation, but their impact on star formation efficiency is more subtle., 28 pages, 11 figures, accepted for publication in A&A