12,954 research outputs found
Enhancing the Prognostic Value of Cardiac Imaging With Multimodal Risk AssessmentââEditorials published in JACC: Cardiovascular Imaging reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Imaging or the American College of Cardiology.
SATMC: Spectral Energy Distribution Analysis Through Markov Chains
We present the general purpose spectral energy distribution (SED) fitting
tool SED Analysis Through Markov Chains (SATMC). Utilizing Monte Carlo Markov
Chain (MCMC) algorithms, SATMC fits an observed SED to SED templates or models
of the user's choice to infer intrinsic parameters, generate confidence levels
and produce the posterior parameter distribution. Here we describe the key
features of SATMC from the underlying MCMC engine to specific features for
handling SED fitting. We detail several test cases of SATMC, comparing results
obtained to traditional least-squares methods, which highlight its accuracy,
robustness and wide range of possible applications. We also present a sample of
submillimetre galaxies that have been fitted using the SED synthesis routine
GRASIL as input. In general, these SMGs are shown to occupy a large volume of
parameter space, particularly in regards to their star formation rates which
range from ~30-3000 M_sun yr^-1 and stellar masses which range from
~10^10-10^12 M_sun. Taking advantage of the Bayesian formalism inherent to
SATMC, we also show how the fitting results may change under different
parametrizations (i.e., different initial mass functions) and through
additional or improved photometry, the latter being crucial to the study of
high-redshift galaxies.Comment: 17 pages, 11 figures, MNRAS accepte
A critical review of anti-adrenergic therapy in patients with heart failure and diabetes mellitus
Anti-adrenergic therapy has been widely accepted as an important therapeutic intervention in patients with chronic heart failure. However, there has been continuing controversy regarding the risks and clinical significance of metabolic effects of different anti-adrenergic drugs. This review summarizes what has been learned from clinical trial evidence regarding the benefits of anti-adrenergic drugs in diabetic patients with chronic heart failure
Agonist/Inosital Trisphosphate-Induced Release of Calcium from Murine Keratinocytes: A Possible Link with Keratinocyte Differentiation
Extracellular calcium concentrations markedly affect the pattern of proliferation and differentiation in cultured keratinocytes. When medium contains 0.1 mM calcium or above, the cells lose their proliferative ability, rapidly stratify, and terminally differentiate. Because 1,25(OH)2D3 (a modulator of Ca++ homeostasis) enhances the differentiation of keratinocytes, we investigated whether a link exists between 1 ,25(OH)2D3-induced release of inositol-1,4,5-trisphosphate (Ins(1,4,5)P3) from Ptdlns 4,5-P2 and intracellular calcium [Ca++]i release from keratinocytes. Specifically, primary culture of keratinocytes were loaded with fluorescence dye Fura-2AM (10 ÎŒM) and changes in fluorescence intensity were monitored at the excitation wavelengths of 340 and 380 nm and emission wavelength of 505 nm. Additions of two agonists, 1,25(OH)2D3 (1.2 Ă 10-9 M) and 13-Cis retinoic acid (0.2 Ă 10-9 M), to dye-loaded keratinocytes induced rapid release of [Ca++]i, respectively, followed by gradual return to the prestimulated state. Addition of Ins(1,4,5)P3 (10) to saponin-treated (leaky) keratinocytes also resulted in a rapid release of [Ca]. In contrast, the addition of inositrol-1,3,4,5-tetrakisphosphate. Ins(1,3,4,5)P at similar concentration exerted negligible effect. Taken together, these results support the view that 1,25(OH)2D3-induced [Ca++]i release in keratinocytes may be via the Ins(1,4,5)P3 induced early release of intracellular [Ca++]. This may explain, at least in part, 1,25(Oh)2D3-enhanced keratinocyte differentiatin
THEMIS Observations of the Magnetopause Electron Diffusion Region: Large Amplitude Waves and Heated Electrons
We present the first observations of large amplitude waves in a well-defined
electron diffusion region at the sub-solar magnetopause using data from one
THEMIS satellite. These waves identified as whistler mode waves, electrostatic
solitary waves, lower hybrid waves and electrostatic electron cyclotron waves,
are observed in the same 12-sec waveform capture and in association with
signatures of active magnetic reconnection. The large amplitude waves in the
electron diffusion region are coincident with abrupt increases in electron
parallel temperature suggesting strong wave heating. The whistler mode waves
which are at the electron scale and enable us to probe electron dynamics in the
diffusion region were analyzed in detail. The energetic electrons (~30 keV)
within the electron diffusion region have anisotropic distributions with
T_{e\perp}/T_{e\parallel}>1 that may provide the free energy for the whistler
mode waves. The energetic anisotropic electrons may be produced during the
reconnection process. The whistler mode waves propagate away from the center of
the 'X-line' along magnetic field lines, suggesting that the electron diffusion
region is a possible source region of the whistler mode waves
Cardiotonic Modulation in Heart Failure Insights From Traditional Chinese Medicineâ
Medicinal herbs have been used over the past centuries for restoring the body's homeostatic balance. Contemporary use of herbal supplements remains widespread in many cultures as treatment for specific ailments. Many possess cardiovascular actions, and some interact with cardiac medications. However, there is variable scientific evidence with respect to their safety and efficacy, and few have been subjected to the same rigorous evaluation processes and regulations as contemporary pharmaceuticals (1). In the field of heart failure, we have also witnessed the failure of promising naturopathic therapies like hawthorn extract in translating their potential benefits in rigorous clinical trials (2,3)
Improved Tissue-Based Analytical Test Methods for Orellanine, a Biomarker of Cortinarius Mushroom Intoxication.
Orellanine (OR) toxin is produced by mushrooms of the genus Cortinarius which grow in North America and in Europe. OR poisoning is characterized by severe oliguric acute renal failure, with a mortality rate of 10%-30%. Diagnosis of OR poisoning currently hinges on a history of ingestion of Cortinarius mushrooms and histopathology of renal biopsies. A key step in the diagnostic approach is analysis of tissues for OR. Currently, tissue-based analytical methods for OR are nonspecific and lack sensitivity. The objectives of this study were: (1) to develop definitive HPLC and LC-MS/MS tissue-based analytical methods for OR; and (2) to investigate toxicological effects of OR in mice. The HPLC limit of quantitation was 10 ”g/g. For fortification levels of 15 ”g/g to 50 ”g/g OR in kidney, the relative standard deviation was between 1.3% and 9.8%, and accuracy was within 1.5% to 7.1%. A matrix-matched calibration curve was reproduced in this range with a correlation coefficient (r) of 0.97-0.99. The limit of detection was 20 ng/g for LC-MS/MS. In OR-injected mice, kidney OR concentrations were 97 ± 51 ”g/g on Day 0 and 17 ± 1 ”g/g on termination Day 3. Splenic and liver injuries were novel findings in this mouse model. The new tissue-based analytical tests will improve diagnosis of OR poisoning, while the mouse model has yielded new data advancing knowledge on OR-induced pathology. The new tissue-based analytical tests will improve diagnosis of OR poisoning, while the mouse model has yielded new data advancing knowledge on OR-induced pathology
Comparison of Rotational Energies and Rigidity of OCS-paraH_2 and OCS-4He complexes
We analyze the nature of the rotational energy level structure of the OCS-He
and OCS-H_2 complexes with a comparison of exact calculations to several
differentdynamical approximations. We compare with the clamped coordinate
quasiadiabatic approximation that introduces an effective potential for each
asymmetric rotor level, with an effective rotation Hamiltonian constructed from
ground state averages of the inverse of the inertial matrix, and investigate
the usefulness of the Eckart condition to decouple rotations and vibrations of
these weakly bound complexes between linear OCS and 4He or H_2. Comparison with
exact results allows an assessment of the accuracies of the different
approximate methods and indicates which approaches are suitable for larger
clusters of OCS with 4He and with H_2. We find the OCS-H_2 complex is
considerably more rigid than the OCS-4He complex, suggesting that semi-rigid
models are useful for analysis of larger clusters of H_2 with OCS.Comment: accepted by Chem. Phys., 200
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