268 research outputs found
The Trans-Pacific Partnership Agreement: Looking Ahead to the Next Steps
Pressure has been building for the conclusion of the 12-country Trans-Pacific Partnership (TPP) negotiations. Getting the deal done is important, but the TPP is not just another free trade agreement (FTA). It represents the chance to set a trade agenda for the future across a wide range of topics for countries throughout the Asia-Pacific region. This means that the agreement should not be settled in haste. More importantly, it also means that key decisions need to be reached about broader issues related to the institutional structure of the TPP. These decisions must be made now, before the deal is closed, on issues such as how to create the TPP as a living agreement, the formation of a TPP Secretariat, and the clarification of entry conditions for future members such as the People’s Republic of China (PRC). These choices must be made deliberately and carefully even while officials are struggling with reaching closure on the most highly sensitive issues still remaining in the agreement. It will not be easy, but wise decisions are necessary now to ensure the long-term success of the TPP
A Direct Comparison between the use of Double Gray and Multiwavelength Radiative Transfer in a General Circulation Model with and without Radiatively Active Clouds
Inhomogeneous cloud formation and wavelength-dependent phenomena are expected
to shape hot Jupiter atmospheres. We present a General Circulation Model (GCM)
with multiwavelength "picket fence" radiative transfer and radiatively active,
temperature dependent clouds, and compare the results to a double gray routine.
The double gray method inherently fails to model polychromatic effects in hot
Jupiter atmospheres, while picket fence captures these non-gray aspects and
performs well compared to fully wavelength-dependent methods. We compare both
methods with radiatively active clouds and cloud-free models, assessing the
limitations of the double gray method. Although there are broad similarities,
the picket fence models have larger day-night side temperature differences,
non-isothermal upper atmospheres, and multiwavelength effects in the presence
of radiatively active clouds. We model the well-known hot Jupiters HD 189733 b
and HD 209458 b. For the hotter HD 209458 b, the picket fence method prevents
clouds from thermostating dayside temperatures, resulting in hotter upper
atmospheres and the dissipation of dayside clouds. Differences in the
temperature structures are then associated with nuanced differences in the
circulation patterns and clouds. Models of the cooler HD 189733 b have global
cloud coverage, regardless of radiative transfer scheme, whereas there are
larger differences in the models of HD 209458 b, particularly in the extent of
the partial cloud coverage on its dayside. This results in minor changes to the
thermal and reflected light phase curves of HD 189733 b, but more significant
differences for the picket fence and double gray versions of HD 209458 b.Comment: Submitted to ApJ, 31 page
Atomistic Studies of Defect Nucleation during Nanoindentation of Au (001)
Atomistic studies are carried out to investigate the formation and evolution
of defects during nanoindentation of a gold crystal. The results in this
theoretical study complement the experimental investigations [J. D. Kiely and
J. E. Houston, Phys. Rev. B, v57, 12588 (1998)] extremely well. The defects are
produced by a three step mechanism involving nucleation, glide and reaction of
Shockley partials on the {111} slip planes noncoplanar with the indented
surface. We have observed that slip is in the directions along which the
resolved shear stress has reached the critical value of approximately 2 GPa.
The first yield occurs when the shear stresses reach this critical value on all
the {111} planes involved in the formation of the defect. The phenomenon of
strain hardening is observed due to the sessile stair-rods produced by the
zipping of the partials. The dislocation locks produced during the second yield
give rise to permanent deformation after retraction.Comment: 11 pages, 13 figures, submitted to Physical Review
A Lack of Variability Between Repeated Spitzer Phase Curves of WASP-43b
Though the global atmospheres of hot Jupiters have been extensively studied
using phase curve observations, the level of time variability in these data is
not well constrained. To investigate possible time variability in a planetary
phase curve, we observed two full-orbit phase curves of the hot Jupiter
WASP-43b at 4.5 microns using the Spitzer Space Telescope, and reanalyzed a
previous 4.5 micron phase curve from Stevenson et al. (2017). We find no
significant time variability between these three phase curves, which span
timescales of weeks to years. The three observations are best fit by a single
phase curve with an eclipse depth of 3907 +- 85 ppm, a dayside-integrated
brightness temperature of 1479 +- 13 K, a nightside-integrated brightness
temperature of 755 +- 46 K, and an eastward-shifted peak of 10.4 +- 1.8
degrees. To model our observations, we performed 3D general circulation model
simulations of WASP-43b with simple cloud models of various vertical extents.
In comparing these simulations to our observations, we find that WASP-43b
likely has a cloudy nightside that transitions to a relatively cloud-free
dayside. We estimate that any change in WASP-43bs vertical cloud thickness of
more than three pressure scale heights is inconsistent with our observed upper
limit on variation. These observations, therefore, indicate that WASP-43bs
clouds are stable in their vertical and spatial extent over timescales up to
several years. These results strongly suggest that atmospheric properties
derived from previous, single Spitzer phase curve observations of hot Jupiters
likely show us the equilibrium properties of these atmospheres.Comment: 24 pages, 9 figures, Published in the Astronomical Journal (AJ
Reply to “Programming may matter most.” Response to “Metabolic effects of two high-intensity circuit training protocols: Does sequence matter?”
We appreciate the interest that our study elicited and the comments from a reader. We commend the reader of our paper for critically evaluating the protocol and results of the study. Here, we would like to respond to the statement made in the letter. Indeed, the rest intervals were longer and time at VO2max was lower in our study than recommended by Bucheit and Larsen.1 However, because the reader is interested in the practical implications of our study, we ask that they consider the following
Attenuating posttraumatic distress with omega-3 polyunsaturated fatty acids among disaster medical assistance team members after the Great East Japan Earthquake: The APOP randomized controlled trial
Acetylcholine turnover in an autoactive molluscan neuron
1. We have studied acetylcholine (ACh) turnover at the cholinergic synapse between an identified motoneuron, the salivary burster (SB), and the muscle cells of the salivary duct (SD) in the terrestrial mollusk Limax maximus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44284/1/10571_2004_Article_BF00710939.pd
Insights into Eyestalk Ablation Mechanism to Induce Ovarian Maturation in the Black Tiger Shrimp
Eyestalk ablation is commonly practiced in crustacean to induce ovarian maturation in captivity. The molecular mechanism of the ablation has not been well understood, preventing a search for alternative measures to induce ovarian maturation in aquaculture. This is the first study to employ cDNA microarray to examine effects of eyestalk ablation at the transcriptomic level and pathway mapping analysis to identify potentially affected biological pathways in the black tiger shrimp (Penaeus monodon). Microarray analysis comparing between gene expression levels of ovaries from eyestalk-intact and eyestalk-ablated brooders revealed 682 differentially expressed transcripts. Based on Hierarchical clustering of gene expression patterns, Gene Ontology annotation, and relevant functions of these differentially expressed genes, several gene groups were further examined by pathway mapping analysis. Reverse-transcriptase quantitative PCR analysis for some representative transcripts confirmed microarray data. Known reproductive genes involved in vitellogenesis were dramatically increased during the ablation. Besides these transcripts expected to be induced by the ablation, transcripts whose functions involved in electron transfer mechanism, immune responses and calcium signal transduction were significantly altered following the ablation. Pathway mapping analysis revealed that the activation of gonadotropin-releasing hormone signaling, calcium signaling, and progesterone-mediated oocyte maturation pathways were putatively crucial to ovarian maturation induced by the ablation. These findings shed light on several possible molecular mechanisms of the eyestalk ablation effect and allow more focused investigation for an ultimate goal of finding alternative methods to replace the undesirable practice of the eyestalk ablation in the future
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