4,522 research outputs found
A dynamical model of the local cosmic expansion
We combine the equations of motion that govern the dynamics of galaxies in
the local volume with Bayesian techniques in order to fit orbits to published
distances and velocities of galaxies within Mpc. We find a Local Group
(LG) mass that is consistent with the
combined dynamical masses of M31 and the Milky Way, and a mass ratio
that rules out models where our Galaxy is more massive
than M31 with confidence. The Milky Way's circular velocity at the
solar radius is relatively high, km/s, which helps to reconcile the
mass derived from the local Hubble flow with the larger value suggested by the
`timing argument'. Adopting {\it Planck}'s bounds on yields a
(local) Hubble constant km/s/Mpc which is consistent with the
value found on cosmological scales. Restricted N-body experiments show that
substructures tend to fall onto the LG along the Milky Way-M31 axis, where the
quadrupole attraction is maximum. Tests against mock data indicate that
neglecting this effect slightly overestimates the LG mass without biasing the
rest of model parameters. We also show that both the time-dependence of the LG
potential and the cosmological constant have little impact on the observed
local Hubble flow.Comment: 22 pages, 14 figures. Accepted to MNRAS. An error in the apex
calculation (Appendix A) was found and has been fixed. The new constraints
favour models where the Milky Way is less massive than M31. The rest of model
parameters and conclusions remain unchange
Edscottite, Fe_5C_2, a New Iron Carbide Mineral from the Wedderburn Iron Meteorite
The Wedderburn iron meteorite, found as a single 210-g mass in Victoria, Australia in 1951, is a
Ni-rich ataxite belonging to subgroup sLH of the IAB complex (Low-Au, High-Ni subgroup). It is one of the most
Ni-rich irons known (23.4 wt.% Ni [1]), initially classified as group IIID. During a re-investigation of a polished thick
section of Wedderburn, we identified a new iron-carbide mineral, Fe5C2 with the C2/c Pd5B2-type structure, named
âedscottiteâ (Fig. 1). Field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron
back-scatter diffraction (EBSD) and electron probe microanalysis (EPMA) were used to characterize edscottite and
associated phases. This mineral was first identified in Wedderburn [2,3]; synthetic Fe_5C_2 was previously known (e.g.,
[4-6]). We report here the first natural occurrence of Fe_5C_2 in an iron meteorite as a new carbide mineral. Edscottite
(IMA 2018-086a) was approved by the IMA-CNMNC [7]. The mineral name is in honor of Edward (Ed) R. D. Scott,
University of Hawaiâi, USA, for his seminal contributions to meteorite research. He discovered haxonite, (Fe,Ni)_(23)C_6
[8] as well as this new iron carbide [2,3]
Multi-Context Attention for Human Pose Estimation
In this paper, we propose to incorporate convolutional neural networks with a
multi-context attention mechanism into an end-to-end framework for human pose
estimation. We adopt stacked hourglass networks to generate attention maps from
features at multiple resolutions with various semantics. The Conditional Random
Field (CRF) is utilized to model the correlations among neighboring regions in
the attention map. We further combine the holistic attention model, which
focuses on the global consistency of the full human body, and the body part
attention model, which focuses on the detailed description for different body
parts. Hence our model has the ability to focus on different granularity from
local salient regions to global semantic-consistent spaces. Additionally, we
design novel Hourglass Residual Units (HRUs) to increase the receptive field of
the network. These units are extensions of residual units with a side branch
incorporating filters with larger receptive fields, hence features with various
scales are learned and combined within the HRUs. The effectiveness of the
proposed multi-context attention mechanism and the hourglass residual units is
evaluated on two widely used human pose estimation benchmarks. Our approach
outperforms all existing methods on both benchmarks over all the body parts.Comment: The first two authors contribute equally to this wor
RGS10 shapes the hemostatic response to injury through its differential effects on intracellular signaling by platelet agonists.
Platelets express â„2 members of the regulators of G protein signaling (RGS) family. Here, we have focused on the most abundant, RGS10, examining its impact on the hemostatic response in vivo and the mechanisms involved. We have previously shown that the hemostatic thrombi formed in response to penetrating injuries consist of a core of fully activated densely packed platelets overlaid by a shell of less-activated platelets responding to adenosine 5\u27-diphosphate (ADP) and thromboxane A2 (TxA2). Hemostatic thrombi formed in RGS10-/- mice were larger than in controls, with the increase due to expansion of the shell but not the core. Clot retraction was slower, and average packing density was reduced. Deleting RGS10 had agonist-specific effects on signaling. There was a leftward shift in the dose/response curve for the thrombin receptor (PAR4) agonist peptide AYPGKF but no increase in the maximum response. This contrasted with ADP and TxA2, both of which evoked considerably greater maximum responses in RGS10-/- platelets with enhanced Gq- and Gi-mediated signaling. Shape change, which is G13-mediated, was unaffected. Finally, we found that free RGS10 levels in platelets are actively regulated. In resting platelets, RGS10 was bound to 2 scaffold proteins: spinophilin and 14-3-3Îł. Platelet activation caused an increase in free RGS10, as did the endothelium-derived platelet antagonist prostacyclin. Collectively, these observations show that RGS10 serves as an actively regulated node on the platelet signaling network, helping to produce smaller and more densely packed hemostatic thrombi with a greater proportion of fully activated platelets
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Do Outcomes of Arthroscopic Subscapularis Tendon Repairs Depend on Rotator Cuff Fatty Infiltration?
Background:Rotator cuff fatty infiltration has been correlated with poorer radiographic and clinical outcomes in supraspinatus and infraspinatus tendon repairs, but this has not been well-studied in subscapularis tendon repairs. Purpose:To evaluate the influence of preoperative rotator cuff fatty infiltration on postoperative outcomes for patients undergoing arthroscopic subscapularis tendon repair. Study Design:Cohort study; Level of evidence, 3. Methods:Patients who underwent arthroscopic subscapularis repair between 2010 and 2016 were retrospectively identified, and demographic data and surgical findings were recorded. The extent of fatty infiltration was determined on preoperative magnetic resonance imaging by the Fuchs modification of the Goutallier classification. At the most recent follow-up, patients completed the Patient-Reported Outcomes Measurement Information System for Upper Extremity (PROMIS-UE) computer adaptive test and a postoperative visual analog scale for pain. The distribution of fatty infiltration was compared between patients undergoing subscapularis tendon repair versus subscapularis tendon repair combined with a posterior cuff repair. Outcomes were compared for patients using Goutallier grade 0-1 versus grade â„2 changes in each rotator cuff muscle. Multivariate linear regression analysis was performed to evaluate the influence of muscle quality, as well as demographic factors, on PROMIS-UE scores. Significance was defined as P < .05. Results:There were 140 shoulders included (mean age, 61.8 years; 42.1% female; mean follow-up, 51.7 months). The prevalence of Goutallier grade 2 changes or higher was significantly greater in patients with multitendon repair relative to isolated subscapularis tendon repair. For the overall group of all patients undergoing subscapularis tendon repair, whether in isolation or as part of a multitendon repair, PROMIS-UE scores were significantly lower for patients with infraspinatus muscle grade 2 or higher Goutallier changes relative to grade 0 or 1. After adjustment for age, body mass index, patient sex, and fatty infiltration in other rotator cuff muscles, poor infraspinatus muscle quality remained the only significant predictor for lower PROMIS-UE scores. Conclusion:Patients undergoing arthroscopic subscapularis tendon repair with poor infraspinatus muscle quality had worse patient-reported outcomes. This was true whether subscapularis tendon repair was isolated or was performed in conjunction with supraspinatus and infraspinatus tendon repairs
Diskursus Khilafah dalam Media Televisi Indonesia (Studi Analisis Wacana Kritis Program Acara Aiman episode âMendadak Khilafahâ di KompasTV)
In Indonesian case, media used to be a tool of government to dominate the universe of discourse, so the discourse that considered as an opposition and threaten the existence of political sturcture, will not have any space. In this reformation era, the media freely rise again with many kinds of importance. Includes KompasTV media, when which appoint khilafah theme that shown on the television program called Aiman, in Monday, 12th of June 2017. Aiman talked about khilafah theme, which is hot topic in society life. In critisism paradigm, the using of language in media it is not a natural and not neutral, but it is intentionally done with some purpose behind it. By looking in this case, the writer interests to know khilafah discourse that will be constructed in KompasTV by the mentioned television program. This analytical unit in form of spoken text and the written text in Aiman, which entittled âMendadak Khilafah.â The writer uses discourse theory by Michel Foucault to uncover how is the dominance practical doing. By using critical discourse analysis technique, by Norman Fairclough which has result that KompasTV constructs khilafah discourse considered as negative ideology, dangerous, and positioned as forbiden idea which can be threatening the unity of nation. This discourse also shows that KompasTV is the part of media member to prepatuate dominant ideolgy that embraced by this nation. KompasTV practicing discrimination and excision to khilafah ideology, because the struggle of enforcement of khilafah in Indonesia assumed as confrontanting and threatening the structure of nation authority which exist
HoxA9 binds and represses the Cebpa +8 kb enhancer
C/EBPα plays a key role in specifying myeloid lineage development. HoxA9 is expressed in myeloid progenitors, with its level diminishing during myeloid maturation, and HOXA9 is over-expressed in a majority of acute myeloid leukemia cases, including those expressing NUP98-HOXD13. The objective of this study was to determine whether HoxA9 directly represses Cebpa gene expression. We find 4-fold increased HoxA9 and 5-fold reduced Cebpa in marrow common myeloid and LSK progenitors from Vav-NUP98-HOXD13 transgenic mice. Conversely, HoxA9 decreases 5-fold while Cebpa increases during granulocytic differentiation of 32Dcl3 myeloid cells. Activation of exogenous HoxA9-ER in 32Dcl3 cells reduces Cebpa mRNA even in the presence of cycloheximide, suggesting direct repression. Cebpa transcription in murine myeloid cells is regulated by a hematopoietic-specific +37 kb enhancer and by a more widely active +8 kb enhancer. ChIP-Seq analysis of primary myeloid progenitor cells expressing exogenous HoxA9 or HoxA9-ER demonstrates that HoxA9 localizes to both the +8 kb and +37 kb Cebpa enhancers. Gel shift analysis demonstrates HoxA9 binding to three consensus sites in the +8 kb enhancer, but no affinity for the single near-consensus site present in the +37 kb enhancer. Activity of a Cebpa +8 kb enhancer/promoter-luciferase reporter in 32Dcl3 or MOLM14 myeloid cells is increased ~2-fold by mutation of its three HOXA9-binding sites, suggesting that endogenous HoxA9 represses +8 kb Cebpa enhancer activity. In contrast, mutation of five C/EBPα-binding sites in the +8 kb enhancer reduces activity 3-fold. Finally, expression of a +37 kb enhancer/promoter-hCD4 transgene reporter is reduced ~2-fold in marrow common myeloid progenitors when the Vav-NUP98-HOXD13 transgene is introduced. Overall, these data support the conclusion that HoxA9 represses Cebpa expression, at least in part via inhibition of its +8 kb enhancer, potentially allowing normal myeloid progenitors to maintain immaturity and contributing to the pathogenesis of acute myeloid leukemia associated with increased HOXA9
Non-Deterministic Abstract Machines
We present a generic design of abstract machines for non-deterministic programming languages, such as process calculi or concurrent lambda calculi, that provides a simple way to implement them. Such a machine traverses a term in the search for a redex, making non-deterministic choices when several paths are possible and backtracking when it reaches a dead end, i.e., an irreducible subterm. The search is guaranteed to terminate thanks to term annotations the machine introduces along the way.
We show how to automatically derive a non-deterministic abstract machine from a zipper semantics - a form of structural operational semantics in which the decomposition process of a term into a context and a redex is made explicit. The derivation method ensures the soundness and completeness of the machines w.r.t. the zipper semantics
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