76 research outputs found
Movement demands of elite rugby league players during Australian National Rugby League and European Super League matches
This is the authors' PDF version as accepted for publication of an article published in International Journal of Sports Physiology and Performance© 2014. The definitive version is available at http://journals.humankinetics.com/ijsppThis study compared the movement demands of players competing in matches from the elite Australian and European rugby league competitions
Mapping Exoplanets
The varied surfaces and atmospheres of planets make them interesting places
to live, explore, and study from afar. Unfortunately, the great distance to
exoplanets makes it impossible to resolve their disk with current or near-term
technology. It is still possible, however, to deduce spatial inhomogeneities in
exoplanets provided that different regions are visible at different
times---this can be due to rotation, orbital motion, and occultations by a
star, planet, or moon. Astronomers have so far constructed maps of thermal
emission and albedo for short period giant planets. These maps constrain
atmospheric dynamics and cloud patterns in exotic atmospheres. In the future,
exo-cartography could yield surface maps of terrestrial planets, hinting at the
geophysical and geochemical processes that shape them.Comment: Updated chapter for Handbook of Exoplanets, eds. Deeg & Belmonte. 17
pages, including 6 figures and 4 pages of reference
Neuropathological Similarities and Differences between Schizophrenia and Bipolar Disorder: A Flow Cytometric Postmortem Brain Study
Recent studies suggest that schizophrenia (SCH) and bipolar disorder (BPD) may share a similar etiopathology. However, their precise neuropathological natures have rarely been characterized in a comprehensive and quantitative fashion. We have recently developed a rapid, quantitative cell-counting method for frozen unfixed postmortem brains using a flow cytometer. In the present study, we not only counted stained nuclei, but also measured their sizes in the gray matter of frontopolar cortices (FPCs) and inferior temporal cortices (ITCs) from patients with SCH or BPD, as well as in that from normal controls. In terms of NeuN(+) neuronal nuclei size, particularly in the reduced densities of small NeuN(+) nuclei, we found abnormal distributions present in the ITC gray matter of both patient groups. These same abnormalities were also found in the FPCs of SCH patients, whereas in the FPCs of BPD patients, a reduction in oligodendrocyte lineage (olig2(+)) cells was much more common. Surprisingly, in the SCH FPC, normal left-greater-than-right asymmetry in neural nuclei densities was almost completely reversed. In the BPD FPC, this asymmetry, though not obvious, differed significantly from that in the SCH FPC. These findings indicate that while similar neuropathological abnormalities are shared by patients with SCH or BPD, differences also exist, mainly in the FPC, which may at least partially explain the differences observed in many aspects in these disorders
When climate science became climate politics: British media representations of climate change in 1988
Climate change has become a pressing environmental concern for scientists, social commentators and politicians. Previous social science research has explored media representations of climate change in various temporal and geographical contexts. Through the lens of Social Representations Theory, this article provides a detailed qualitative thematic analysis of media representations of climate change in the 1988 British broadsheet press, given that this year constitutes an important juncture in this transition of climate change from the domain of science to that of the socio-political sphere. The following themes are outlined: (i) “Climate change: a multi-faceted threat”; (ii) “Collectivisation of threat”; (iii) “Climate change and the attribution of blame”; and (iv) “Speculative solutions to a complex socio-environmental problem.” The article provides detailed empirical insights into the “starting-point” for present-day disputes concerning climate change and lays the theoretical foundations for tracking the continuities and discontinuities characterising social representations of climate change in the future
Identification of carbon dioxide in an exoplanet atmosphere
Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (that is, elements heavier than helium, also called ‘metallicity’)1–3, and thus the formation processes of the primary atmospheres of hot gas giants4–6. It is also one of the most promising species to detect in the secondary atmospheres of terrestrial exoplanets7–9. Previous photometric measurements of transiting planets with the Spitzer Space Telescope have given hints of the presence of CO2, but have not yielded definitive detections owing to the lack of unambiguous spectroscopic identification10–12. Here we present the detection of CO2 in the atmosphere of the gas giant exoplanet WASP-39b from transmission spectroscopy observations obtained with JWST as part of the Early Release Science programme13,14. The data used in this study span 3.0–5.5 micrometres in wavelength and show a prominent CO2 absorption feature at 4.3 micrometres (26-sigma significance). The overall spectrum is well matched by one-dimensional, ten-times solar metallicity models that assume radiative–convective–thermochemical equilibrium and have moderate cloud opacity. These models predict that the atmosphere should have water, carbon monoxide and hydrogen sulfide in addition to CO2, but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0 micrometres that is not reproduced by these models
Early Release Science of the exoplanetWASP-39b with JWST NIRISS
This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData Availability:
The raw data from this study are publicly available via the Space Science Telescope Institute's
Mikulski Archive for Space Telescopes (https://archive.stsci.edu/). The data which was used to
create all of the figures in this manuscript are freely available on Zenodo and GitHub (Zenodo
Link;https://github.com/afeinstein20/wasp39b_niriss_paper). All additional data is available upon
request.Code Availability:
The following are open-source pipelines written in Python that are available either through the
Python Package Index (PyPI) or GitHub that were used throughout this work:
Eureka! (https://github.com/kevin218/Eureka); nirHiss (https://github.com/afeinstein20/nirhiss);
supreme-SPOON (https://github.com/radicamc/supreme-spoon); transitspectroscopy
(https://github.com/nespinoza/transitspectroscopy/tree/dev); iraclis (https://github.com/uclexoplanets/Iraclis); juliet (https://github.com/nespinoza/juliet); chromatic
(https://github.com/zkbt/chromatic); chromatic_fitting
(https://github.com/catrionamurray/chromatic_fitting); ExoTiC-LD54, 121
(https://github.com/Exo-TiC/ExoTiC-LD); ExoTETHyS122 (https://github.com/uclexoplanets/ExoTETHyS); PICASO88,89 (https://github.com/natashabatalha/picaso); Virga94, 95
(https://github.com/natashabatalha/virga); CHIMERA (https://github.com/mrline/CHIMERA);
PyMultiNest (https://github.com/JohannesBuchner/PyMultiNest); MultiNest
(https://github.com/JohannesBuchner/MultiNest)The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality. Here, we present the transmission spectrum of WASP-39 b obtained using the SOSS mode of the NIRISS instrument on JWST. This spectrum spans 0.6–2.8m in wavelength and reveals multiple water absorption bands, the potassium resonance doublet, and signatures of clouds. The precision and broad wavelength coverage of NIRISS-SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39b, favouring a heavy element enhancement (“metallicity”) of ~10–30x the solar value, a sub-solar carbon-to-oxygen (C/O) ratio, and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-gray clouds with inhomogeneous coverage of the planet’s terminator.Leverhulme TrustUK Research and Innovatio
Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H
This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData Availability:
The data used in this paper are associated with JWST program ERS 1366 (observation #4) and
are available from the Mikulski Archive for Space Telescopes (https://mast.stsci.edu). Science
data processing version (SDP_VER) 2022_2a generated the uncalibrated data that we
downloaded from MAST. We used JWST Calibration Pipeline software version (CAL_VER)
1.5.3 with modifications described in the text. We used calibration reference data from context
(CRDS_CTX) 0916, except as noted in the text. All the data and models presented in this
publication can be found at 10.5281/zenodo.7185300.Code Availability:
The codes used in this publication to extract, reduce and analyze the data are as follows;
STScI JWST Calibration pipeline45 (https://github.com/spacetelescope/jwst), Eureka!53
(https://eurekadocs.readthedocs.io/en/latest/), ExoTiC-JEDI47 (https://github.com/ExoTiC/ExoTiC-JEDI), juliet71 (https://juliet.readthedocs.io/en/latest/), Tiberius15,49,50,
transitspectroscopy51 (https://github.com/nespinoza/transitspectroscopy). In addition, these
made use of batman65 (http://lkreidberg.github.io/batman/docs/html/index.html), celerite86
(https://celerite.readthedocs.io/en/stable/), chromatic (https://zkbt.github.io/chromatic/),
Dynesty72 (https://dynesty.readthedocs.io/en/stable/index.html), emcee69
(https://emcee.readthedocs.io/en/stable/), exoplanet83 (https://docs.exoplanet.codes/en/latest/),
ExoTEP75–77, ExoTHETyS79 (https://github.com/ucl-exoplanets/ExoTETHyS), ExoTiCISM57 (https://github.com/Exo-TiC/ExoTiC-ISM), ExoTiC-LD58 (https://exoticld.readthedocs.io/en/latest/), george68 (https://george.readthedocs.io/en/latest/) JAX82
(https://jax.readthedocs.io/en/latest/), LMFIT70 (https://lmfit.github.io/lmfit-py/),
Pylightcurve78 (https://github.com/ucl-exoplanets/pylightcurve), Pymc3138
(https://docs.pymc.io/en/v3/index.html) and Starry84 (https://starry.readthedocs.io/en/latest/),
each of which use the standard python libraries astropy139,140, matplotlib141, numpy142,
pandas143, scipy64 and xarray144. The atmospheric models used to fit the data can be found at
ATMO[Tremblin2015,Drummond2016,Goyal2018,Goyal2020]88–91, PHOENIX92–94,
PICASO98,99 (https://natashabatalha.github.io/picaso/), Virga98,107
(https://natashabatalha.github.io/virga/), and gCMCRT115
(https://github.com/ELeeAstro/gCMCRT).Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems. Access to an exoplanet’s chemical inventory requires high precision observations, often inferred from individual molecular detections with low-resolution space-based and high-resolution ground-based facilities. Here we report the medium-resolution (R≈600) transmission spectrum of an exoplanet atmosphere between 3–5 μm covering multiple absorption features for the Saturn-mass exoplanet WASP-39b, obtained with JWST NIRSpec G395H. Our observations achieve 1.46×
photon precision, providing an average transit depth uncertainty of 221 ppm per spectroscopic bin, and present minimal impacts from systematic effects. We detect significant absorption from CO2 (28.5σ
) and H2O (21.5σ
), and identify SO2 as the source of absorption at 4.1 μ
m (4.8σ
). Best-fit atmospheric models range between 3×
and 10×
solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2, underscore the importance of characterising the chemistry in exoplanet atmospheres, and showcase NIRSpec G395H as an excellent mode for time series observations over this critical wavelength range.Science and Technology Facilities Council (STFC)UKR
Effects of cottonseed meal and cereal grain supplements on intake and utilisation of alkali-treated wheat straw by cattle
Effect on milk production of adding bentonite and reactive limestone to maize grain supplements for grazing cows
Responses to protein meal supplements by lactating beef cattle given a low-quality pasture hay
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