The use of antimicrobials in food-producing animals has been linked with the emergence of antimicrobial resistance in bacterial populations, with consequences for animal and public health. This study ...explored the underpinning drivers, motivators and reasoning behind prescribing decisions made by veterinary surgeons working in the UK pig industry.
A qualitative interview study was conducted with 21 veterinary surgeons purposively selected from all UK pig veterinary surgeons. Thematic analysis was used to analyse transcripts.
Ensuring optimum pig health and welfare was described as a driver for antimicrobial use by many veterinary surgeons and was considered a professional and moral obligation. Veterinary surgeons also exhibited a strong sense of social responsibility over the need to ensure that antimicrobial use was responsible. A close relationship between management practices, health and economics was evident, with improvements in management commonly identified as being potential routes to reduce antimicrobial usage; however, these were not always considered economically viable. The relationship with clients was identified as being a source of professional stress for practitioners due to pressure from farmers requesting antimicrobial prescriptions, and concern over poor compliance of antimicrobial administration by some farmers.
The drivers behind prescribing decisions by veterinary surgeons were complex and diverse. A combination of education, improving communication between veterinary surgeons and farmers, and changes in regulations, in farm management and in consumer/retailer demands may all be needed to ensure that antimicrobial prescribing is optimal and to achieve significant reductions in use.
Increasing levels of antimicrobial resistance in human and veterinary medicine have raised concerns around the issue of overprescribing and the indiscriminate use of antimicrobials. Their use in food ...producing animals is under scrutiny due to the perceived risk from the zoonotic transfer of resistant pathogens from animals to humans. This study aimed to explore UK veterinary surgeons antimicrobial prescribing behaviours, their attitudes to antimicrobial resistance and their perceptions of responsibility of antimicrobial use in pigs through a questionnaire study on a census sample of 261 veterinary surgeons in England, Wales and Scotland who had a clinical caseload which included commercial pigs. The questionnaire had a useable response rate of 34.1% (n = 61/179) in eligible veterinary surgeons.
Overall, veterinary surgeons reported personal confidence that their prescribing decisions were responsible however, there was concern that the prescribing behaviours of other veterinary surgeons and physicians in human medicine may be less responsible; a sociological concept known as ‘othering’. In parallel, veterinary surgeons seldom identified that treatment failure was a consequence of antimicrobial resistance in their own clinical caseload, however they considered it an issue for other veterinary surgeons and for human prescribers. Veterinary surgeons consulted a wide spectrum of resources on antimicrobial use in pigs which, on occasion, contained conflicting guidance on what was defined as responsible prescribing. The decision over whether or not to prescribe an antimicrobial was influenced by numerous factors relating to the veterinary surgeons’ experience and the clinical situation presented, but maintaining pig welfare was a high priority. There was a shared desire to seek alternative methods to prevent disease to antimicrobial use, however the use of diagnostics to support prescribing decisions was an infrequently reported behaviour and could play a more significant role in prescriber decisions if more cost effective and rapid tests were available.
Future interventions to optimise antimicrobial use in pigs needs to focus on the evolution of antimicrobial use practices in a changing political and scientific landscape whilst also considering individual motivations and justifications for use.
We present the discovery and characterization of two sub-Neptunes in close orbits, as well as a tentative outer planet of a similar size, orbiting TOI-1260 – a low metallicity K6 V dwarf star. ...Photometry from Transiting Exoplanet Survey Satellite(TESS) yields radii of R(b) = 2.33 ± 0.10 and R(c) = 2.82 ± 0.15 Rꚛ, and periods of 3.13 and 7.49 d for TOI-1260 b and TOI-1260 c, respectively. We combined the TESS data with a series of ground-based follow-up observations to characterize the planetary system. From HARPS-N high-precision radial velocities we obtain M(b) = 8.6(+1.4,−1.5) and M(c) = 11.8(+3.4,−3.2) Mꚛ. The star is moderately active with a complex activity pattern, which necessitated the use of Gaussian process regression for both the light-curve detrending and the radial velocity modelling, in the latter case guided by suitable activity indicators. We successfully disentangle the stellar-induced signal from the planetary signals, underlining the importance and usefulness of the Gaussian process approach. We test the system’s stability against atmospheric photoevaporation and find that the TOI-1260 planets are classic examples of the structure and composition ambiguity typical for the 2–3 Rꚛ range.
The Transiting Exoplanet Survey Satellite, TESS, is currently carrying out an all-sky search for small planets transiting bright stars. In the first year of the TESS survey, a steady progress was ...made in achieving the mission’s primary science goal of establishing bulk densities for 50 planets smaller than Neptune. During that year, the TESS’s observations were focused on the southern ecliptic hemisphere, resulting in the discovery of three mini-Neptunes orbiting the star TOI-125, a V = 11.0 K0 dwarf. We present intensive HARPS radial velocity observations, yielding precise mass measurements for TOI-125b, TOI-125c, and TOI-125d. TOI-125b has an orbital period of 4.65 d, a radius of 2.726 ± 0.075 R(E), a mass of 9.50 ± 0.88 M(E), and is near the 2:1 mean motion resonance with TOI-125c at 9.15 d. TOI-125c has a similar radius of 2.759 ± 0.10 R(E) and a mass of 6.63 ± 0.99 M(E), being the puffiest of the three planets. TOI-125d has an orbital period of 19.98 d and a radius of 2.93 ± 0.17 R(E) and mass 13.6 ± 1.2 M(E). For TOI-125b and d, we find unusual high eccentricities of 0.19 ± 0.04 and 0.17(sup +0.08, sub −0.06), respectively. Our analysis also provides upper mass limits for the two low-SNR planet candidates in the system; for TOI-125.04 (R(P) = 1.36 R(E), P = 0.53 d), we find a 2σ upper mass limit of 1.6 M(E), whereas TOI-125.05 (R(P) = 4.2(sup +2.4, sub −1.4 R(E), P = 13.28 d) is unlikely a viable planet candidate with an upper mass limit of 2.7 M(E). We discuss the internal structure of the three confirmed planets, as well as dynamical stability and system architecture for this intriguing exoplanet system.
Context. Transiting sub-Neptune-type planets, with radii approximately between 2 and 4R⊕, are of particular interest as their study allows us to gain insight into the formation and evolution of a ...class of planets that are not found in our Solar System. Aims. We exploit the extreme radial velocity (RV) precision of the ultra-stable echelle spectrograph ESPRESSO on the VLT to unveil the physical properties of the transiting sub-Neptune TOI-130 b, uncovered by the TESS mission orbiting the nearby, bright, late F-typestar HD 5278 (TOI-130) with a period of Pb=14.3 days. Methods. We used 43 ESPRESSO high-resolution spectra and broad-band photometry information to derive accurate stellar atmospheric and physical parameters of HD 5278. We exploited the TESS light curve and spectroscopic diagnostics to gauge the impact of stellar activity on the ESPRESSO RVs. We performed separate as well as joint analyses of the TESS photometry and the ESPRESSORVs using fully Bayesian frameworks to determine the system parameters. Results. Based on the ESPRESSO spectra, the updated stellar parameters of HD 5278 are Teff=6203±64K, logg=4.50±0.11dex, Fe/H =−0.12±0.04dex,M?=1.126+0.036−0.035M, and R?=1.194+0.017−0.016R. We determine HD 5278 b’s mass and radius to be Mb=7.8+1.5−1.4M⊕ and Rb=2.45±0.05R⊕. The derived mean density, %b=2.9+0.6−0.5g cm−3, is consistent with the bulk composition of a sub-Neptune with a substantial (∼30%) water mass fraction and with a gas envelope comprising ∼17% of the measured radius. Given the host brightness and irradiation levels, HD 5278 b is one of the best targets orbiting G-F primaries for follow-up atmospheric characterization measurements with HST and JWST. We discover a second, non-transiting companion in the system, with a period of Pc=40.87+0.18−0.17days and a minimum mass of Mcsinic=18.4+1.8−1.9M⊕. We study emerging trends in parameters space (e.g., mass, radius, stellar insolation, and mean density) of the growing population of transiting sub-Neptunes, and provide statistical evidence for a low occurrence of close-in,10−15M⊕companions around G-F primaries withTeff&5500K.
Sentinel species are increasingly used by disease managers to detect and monitor the prevalence of zoonotic diseases in wildlife populations. Characterizing home-range movements of sentinel hosts is ...thus important for developing improved disease surveillance methods, especially in systems where multiple host species co-exist. We studied ranging activity of major hosts of bovine tuberculosis (TB) in an upland habitat of New Zealand: we compared home-range coverage by ferrets (Mustela furo), wild deer (Cervus elaphus), feral pigs (Sus scrofa), brushtail possums (Trichosurus vulpecula) and free-ranging farmed cattle (Bos taurus). We also report in detail the proportional utilization of a seasonal (4-monthly) range area for the latter four species. Possums covered the smallest home range (<30 ha), ferrets covered ∼100 ha, pigs ∼4 km2, deer and cattle both >30 km2. For any given weekly period, cattle, deer and pigs were shown to utilize 37–45% of their estimated 4-month range, while possums utilized 62% during any weekly period and 85% during any monthly period of their estimated 4-month range. We suggest that present means for estimating TB detection kernels, based on long-term range size estimates for possums and sentinel species, probably overstate the true local surveillance coverage per individual.
We report the discovery and characterization of two transiting planets around the bright M1 V star LP 961-53 (TOI-776,
J
= 8.5 mag,
M
= 0.54 ± 0.03
M
⊙
) detected during Sector 10 observations of the ...Transiting Exoplanet Survey Satellite (TESS). Combining the TESS photometry with HARPS radial velocities, as well as ground-based follow-up transit observations from the MEarth and LCOGT telescopes, for the inner planet, TOI-776 b, we measured a period of
P
b
= 8.25 d, a radius of
R
b
= 1.85 ± 0.13
R
⊕
, and a mass of
M
b
= 4.0 ± 0.9
M
⊕
; and for the outer planet, TOI-776 c, a period of
P
c
= 15.66 d, a radius of
R
c
= 2.02 ± 0.14
R
⊕
, and a mass of
M
c
= 5.3 ± 1.8
M
⊕
. The Doppler data shows one additional signal, with a period of ~34 d, associated with the rotational period of the star. The analysis of fifteen years of ground-based photometric monitoring data and the inspection of different spectral line indicators confirm this assumption. The bulk densities of TOI-776 b and c allow for a wide range of possible interior and atmospheric compositions. However, both planets have retained a significant atmosphere, with slightly different envelope mass fractions. Thanks to their location near the radius gap for M dwarfs, we can start to explore the mechanism(s) responsible for the radius valley emergence around low-mass stars as compared to solar-like stars. While a larger sample of well-characterized planets in this parameter space is still needed to draw firm conclusions, we tentatively estimate that the stellar mass below which thermally-driven mass loss is no longer the main formation pathway for sculpting the radius valley is between 0.63 and 0.54
M
⊙
. Due to the brightness of the star, the TOI-776 system is also an excellent target for the
James Webb
Space Telescope, providing a remarkable laboratory in which to break the degeneracy in planetary interior models and to test formation and evolution theories of small planets around low-mass stars.
Context . Long-period transiting exoplanets bridge the gap between the bulk of transit- and Doppler-based exoplanet discoveries, providing key insights into the formation and evolution of planetary ...systems. The wider separation between these planets and their host stars results in the exoplanets typically experiencing less radiation from their host stars; hence, they should maintain more of their original atmospheres, which can be probed during transit via transmission spectroscopy. Although the known population of long-period transiting exoplanets is relatively sparse, surveys performed by the Transiting Exoplanet Survey Satellite (TESS) and the Next Generation Transit Survey (NGTS) are now discovering new exoplanets to fill in this crucial region of the exoplanetary parameter space. Aims . This study aims to characterise a new long-period transiting exoplanet by following up on a single-transit candidate found in the TESS mission. Methods . The TOI-4862 system was monitored using a combination of photometric instruments (TESS, NGTS, and EulerCam) and spectroscopic instruments (CORALIE, FEROS, HARPS, and PFS) in order to determine the period, radius, and mass of the long-period transiting exoplanet NGTS-30 b/TOI-4862 b. These observations were then fitted simultaneously to determine precise values for the properties and orbital parameters of the exoplanet, as well as the refined stellar parameters of the host star. Results . We present the discovery of a long-period ( P = 98.29838 ± 0.00010 day) Jupiter-sized (0.928 ± 0.032 R J ; 0.960 ± 0.056 M J ) planet transiting a 1.1 Gyr old G-type star, one of the youngest warm Jupiters discovered to date. NGTS-30 b/TOI-4862 b has a moderate eccentricity (0.294 −0.010 +0.014 ), meaning that its equilibrium temperature can be expected to vary from 274 −46 +30 K to 500 −84 +55 K over the course of its orbit. Through interior modelling, NGTS-30 b/TOI-4862b was found to have a heavy element mass fraction of 0.23 −0.06 +0.05 and a heavy element enrichment ( Z p / Z ★ ) of 20 −6 +5 , making it metal-enriched compared to its host star. Conclusions . NGTS-30 b/TOI-4862 b is one of the youngest well-characterised long-period exoplanets found to date and will therefore be important in the quest to understanding the formation and evolution of exoplanets across the full range of orbital separations and ages.
The GAPS programme with HARPS-N at TNG Malavolta, L.; Nascimbeni, V.; Piotto, G. ...
Astronomy and astrophysics (Berlin),
4/2016, Letnik:
588
Journal Article
ABSTRACT
Transiting exoplanets orbiting young nearby stars are ideal laboratories for testing theories of planet formation and evolution. However, to date only a handful of stars with age <1 Gyr have ...been found to host transiting exoplanets. Here we present the discovery and validation of a sub-Neptune around HD 18599 , a young (300 Myr), nearby (d = 40 pc) K star. We validate the transiting planet candidate as a bona fide planet using data from the TESS , Spitzer , and Gaia missions, ground-based photometry from IRSF , LCO , PEST , and NGTS , speckle imaging from Gemini, and spectroscopy from CHIRON , NRES , FEROS , and Minerva-Australis . The planet has an orbital period of 4.13 d , and a radius of 2.7 R⊕ . The RV data yields a 3-σ mass upper limit of 30.5 M⊕ which is explained by either a massive companion or the large observed jitter typical for a young star. The brightness of the host star (V∼9 mag) makes it conducive to detailed characterization via Doppler mass measurement which will provide a rare view into the interior structure of young planets.