328 research outputs found
Effect of water temperature on cattle performance
When average outside air temperature was about 40 F, water temperatures of 40, 60, Of\u27 80 F had little effect on water intakes of yearling steers and heifers. In addition, there were no significant differences in average daily feed or efficiency. No electrical energy was required to maintain water at 40 F, and it took about twice as much electricity to maintain water at 80 F instead of 60 F
Magnetic Flux Cancellation as the Trigger Mechanism of Solar Coronal Jets
Coronal jets are narrow eruptions in the solar corona, and are often observed in extreme ultraviolet (EUV) and X-Ray images. They occur everywhere on the solar disk: in active regions, quiet regions, and coronal holes (Raouafi et al. 2016). Recent studies indicate that most coronal jets in quiet regions and coronal holes are driven by the eruption of a minifilament (Sterling et al. 2015), and that this eruption follows flux cancellation at the magnetic neutral line under the pre-eruption minifilament (Panesar et al. 2016). We confirm this picture for a large sample of jets in quiet regions and coronal holes using multithermal extreme ultraviolet (EUV) images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and line-of-sight magnetograms from the SDO/Helioseismic and Magnetic Imager (HMI). We report observations of 60 randomly selected jet eruptions. We have analyzed the magnetic cause of these eruptions and measured the base size and the duration of each jet using routines in SolarSoft IDL. By examining the evolutionary changes in the magnetic field before, during, and after jet eruption, we found that each of these jets resulted from minifilament eruption triggered by flux cancellation at the neutral line. In agreement with the above studies, we found our jets to have an average base diameter of 7600 +/- 2700 km and an average jet-growth duration of 9.0 +/- 3.6 minutes. These observations confirm that minifilament eruption is the driver and that magnetic flux cancellation is the primary trigger mechanism for nearly all coronal hole and quiet region coronal jet eruptions
Global MHD Simulations of the Time-Dependent Corona
We describe, test, and apply a technique to incorporate full-sun, surface
flux evolution into an MHD model of the global solar corona. Requiring only
maps of the evolving surface flux, our method is similar to that of Lionello et
al. (2013), but we introduce two ways to correct the electric field at the
lower boundary to mitigate spurious currents. We verify the accuracy of our
procedures by comparing to a reference simulation, driven with known flows and
electric fields. We then present a thermodynamic MHD calculation lasting one
solar rotation driven by maps from the magnetic flux evolution model of
Schrijver & DeRosa (2003). The dynamic, time-dependent nature of the model
corona is illustrated by examining the evolution of the open flux boundaries
and forward modeled EUV emission, which evolve in response to surface flows and
the emergence and cancellation flux. Although our main goal is to present the
method, we briefly investigate the relevance of this evolution to properties of
the slow solar wind, examining the mapping of dipped field lines to the
topological signatures of the "S-Web" and comparing charge state ratios
computed in the time-dependently driven run to a steady state equivalent.
Interestingly, we find that driving on its own does not significantly improve
the charge states ratios, at least in this modest resolution run that injects
minimal helicity. Still, many aspects of the time-dependently driven model
cannot be captured with traditional steady-state methods, and such a technique
may be particularly relevant for the next generation of solar wind and CME
models
Reflection Spectroscopy of the Black Hole Binary XTE J1752-223 in its Long-Stable Hard State
We present a detailed spectral analysis of the Black Hole Binary XTE
J1752-223 in the hard state of its 2009 outburst. Regular monitoring of this
source by RXTE provided high signal-to-noise spectra along the outburst rise
and decay. During one full month this source stalled at 30\% of its peak
count rate at a constant hardness and intensity. By combining all the data in
this exceptionally-stable hard state, we obtained an aggregate PCA spectrum
(3-45 keV) with 100 million counts, and a corresponding HEXTE spectrum (20-140
keV) with 5.8 million counts. Implementing a version of our reflection code
with a physical model for Comptonization, we obtain tight constraints on
important physical parameters for this system. In particular, the inner
accretion disk is measured very close in, at .
Assuming , we find a relatively high black hole
spin (). Imposing a lamppost geometry, we obtain a low
inclination ( deg), which agrees with the upper limit found in the
radio ( deg). However, we note that this model cannot be statistically
distinguished from a non-lamppost model with free emissivity index, for which
the inclination is markedly higher. Additionally, we find a relatively cool
corona ( keV), and large iron abundance ( solar). We further
find that properly accounting for Comptonization of the reflection emission
improves the fit significantly and causes an otherwise low reflection fraction
() to increase by an order of magnitude, in line with geometrical
expectations for a lamppost corona. We compare these results with similar
investigations reported for GX 339-4 in its bright hard state.Comment: Accepted for publication in ApJ. 11 pages, 7 figure
Measuring and predicting reservoir heterogeneity in complex deposystems: the Late Cambrian Rose Run sandstone of Eastern Ohio and Western Pennsylvania
A cooperative two-year multidisciplinary research program, conducted by the Ohio Division of Geological Survey (ODGS) and the Pennsylvania Bureau of Topographic and Geologic Survey (PTGS), designed to measure and predict reservoir heterogeneity in the Upper Cambrian Rose Run sandstone in those two states.257 pages, 125 figures (including numerous maps, cross sections, seismic lines, and photographs of rock thin sections), 6 tables, and five case studies of Rose Run oil and gas fields.Prepared for U.S. Department of Energy, Assistant Secretary for Fossil Energy. Work performed under Contract No. DE-AC22-90BC14657.This two-year investigation of the Upper Cambrian Rose Run sandstone in Eastern Ohio and Western Pennsylvania was conducted by the Ohio and Pennsylvania Geological Surveys in a cost-sharing agreement with the U.S. Department of Energy under the auspices of the Appalachian Oil and Natural Gas Research Consortium, which consists of West Virginia University and the state geological surveys of Kentucky, Ohio, Pennsylvania, and West Virginia
Efficacy and safety of tafamidis doses in the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) and long-term extension study.
Aims Tafamidis is an effective treatment for transthyretin amyloid cardiomyopathy (ATTR-CM) in the Tafamidis in
Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT). While ATTR-ACT was not designed for a dose-specific
assessment, further analysis from ATTR-ACT and its long-term extension study (LTE) can guide determination of the
optimal dose.
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Methods
and results
In ATTR-ACT, patients were randomized (2:1:2) to tafamidis 80 mg, 20mg, or placebo for 30months. Patients
completing ATTR-ACT could enrol in the LTE (with placebo-treated patients randomized to tafamidis 80 or
20 mg; 2:1) and all patients were subsequently switched to high-dose tafamidis. All-cause mortality was assessed
in ATTR-ACT combined with the LTE (median follow-up 51 months). In ATTR-ACT, the combination of all-cause
mortality and cardiovascular-related hospitalizations over 30 months was significantly reduced with tafamidis 80mg
(P = 0.0030) and 20mg (P = 0.0048) vs. placebo. All-cause mortality vs. placebo was reduced with tafamidis 80mg
[Cox hazards model (95% confidence interval (CI): 0.690 (0.487–0.979), P = 0.0378] and 20mg [0.715 (0.450–1.137),
P = 0.1564]. The mean (standard error) change in N-terminal pro-B-type natriuretic peptide from baseline to Month
30 was −1170.51 (587.31) (P = 0.0468) with tafamidis 80 vs. 20 mg. In ATTR-ACT combined with the LTE there
was a significantly greater survival benefit with tafamidis 80 vs. 20 mg [0.700 (0.501–0.979), P = 0.0374]. Incidence
of adverse events in both tafamidis doses were comparable to placebo.
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Conclusion Tafamidis, both 80 and 20mg, effectively reduced mortality and cardiovascular-related hospitalizations in patients
with ATTR-CM. The longer-term survival data and the lack of dose-related safety concerns support tafamidis 80mg
as the optimal dose.
Clinical Trial Registration: ClinicalTrials.gov NCT01994889; NCT02791230post-print369 K
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