3,127 research outputs found
Management of Mechanical Ventilation in Decompensated Heart Failure.
Mechanical ventilation (MV) is a life-saving intervention for respiratory failure, including decompensated congestive heart failure. MV can reduce ventricular preload and afterload, decrease extra-vascular lung water, and decrease the work of breathing in heart failure. The advantages of positive pressure ventilation must be balanced with potential harm from MV: volutrauma, hyperoxia-induced injury, and difficulty assessing readiness for liberation. In this review, we will focus on cardiac, pulmonary, and broader effects of MV on patients with decompensated HF, focusing on practical considerations for management and supporting evidence
Hubble Space Telescope High Resolution Imaging of Kepler Small and Cool Exoplanet Host Stars
High resolution imaging is an important tool for follow-up study of exoplanet
candidates found via transit detection with the Kepler Mission. We discuss here
HST imaging with the WFC3 of 23 stars that host particularly interesting Kepler
planet candidates based on their small size and cool equilibrium temperature
estimates. Results include detections, exclusion of background stars that could
be a source of false positives for the transits, and detection of
physically-associated companions in a number of cases providing dilution
measures necessary for planet parameter refinement. For six KOIs, we find that
there is ambiguity in which star hosts the transiting planet(s), with
potentially strong implications for planetary characteristics. Our sample is
evenly distributed in G, K, and M spectral types. Albeit with a small sample
size, we find that physically-associated binaries are more common than expected
at each spectral type, reaching a factor of 10 frequency excess at M. We
document the program detection sensitivities, detections, and deliverables to
the Kepler follow-up program archive.Comment: Accepted for the Astronomical Journal; 13 pages with 9 figure
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Improved chemistry restraints for crystallographic refinement by integrating the Amber force field into Phenix.
The refinement of biomolecular crystallographic models relies on geometric restraints to help to address the paucity of experimental data typical in these experiments. Limitations in these restraints can degrade the quality of the resulting atomic models. Here, an integration of the full all-atom Amber molecular-dynamics force field into Phenix crystallographic refinement is presented, which enables more complete modeling of biomolecular chemistry. The advantages of the force field include a carefully derived set of torsion-angle potentials, an extensive and flexible set of atom types, Lennard-Jones treatment of nonbonded interactions and a full treatment of crystalline electrostatics. The new combined method was tested against conventional geometry restraints for over 22 000 protein structures. Structures refined with the new method show substantially improved model quality. On average, Ramachandran and rotamer scores are somewhat better, clashscores and MolProbity scores are significantly improved, and the modeling of electrostatics leads to structures that exhibit more, and more correct, hydrogen bonds than those refined using traditional geometry restraints. In general it is found that model improvements are greatest at lower resolutions, prompting plans to add the Amber target function to real-space refinement for use in electron cryo-microscopy. This work opens the door to the future development of more advanced applications such as Amber-based ensemble refinement, quantum-mechanical representation of active sites and improved geometric restraints for simulated annealing
Epigenetic aging signatures in mice livers are slowed by dwarfism, calorie restriction and rapamycin treatment
Background: Global but predictable changes impact the DNA methylome as we age, acting as a type of molecular
clock. This clock can be hastened by conditions that decrease lifespan, raising the question of whether it can also
be slowed, for example, by conditions that increase lifespan. Mice are particularly appealing organisms for studies of
mammalian aging; however, epigenetic clocks have thus far been formulated only in humans.
Results: We first examined whether mice and humans experience similar patterns of change in the methylome with
age. We found moderate conservation of CpG sites for which methylation is altered with age, with both species
showing an increase in methylome disorder during aging. Based on this analysis, we formulated an epigenetic-aging
model in mice using the liver methylomes of 107 mice from 0.2 to 26.0 months old. To examine whether epigenetic
aging signatures are slowed by longevity-promoting interventions, we analyzed 28 additional methylomes from mice
subjected to lifespan-extending conditions, including Prop1df/df dwarfism, calorie restriction or dietary rapamycin. We
found that mice treated with these lifespan-extending interventions were significantly younger in epigenetic age than
their untreated, wild-type age-matched controls.
Conclusions: This study shows that lifespan-extending conditions can slow molecular changes associated with an
epigenetic clock in mice livers
Efficiency Strategies for Facilitating Computerized Clinical Documentation in Ambulatory Care
Most providers have experienced increased documentation demands with the use of electronic health records (EHRs). We sought to identify efficiency strategies that providers use to complete clinical documentation tasks in ambulatory care. Two observers performed ethnographic observations and interviews with 22 ambulatory care providers in a U.S. Veterans Affairs Medical Center. Observation notes and interview transcripts were coded for recurrent strategies relating to completion of the EHR progress notes. Findings included: the use of paper artifacts for handwritten notations; electronic templates for automation of certain parts of the note; use of shorthand and phrases rather than narrative writing; copying and pasting from previous EHR notes; directly entering information into the EHR note during the patient encounter; reliance on memory; and pre-populating an EHR note prior to seeing the patient. We discuss the findings in the context of distributed cognition to understand how clinical information is propagated and represented toward completion of a progress note. The study findings have important implications for improving and streamlining clinical documentation related to human factors workload management strategies
LEND ME YOUR EAAR: ENHANCING THE AFTER ACTION REVIEW TO INCREASE TACTICAL LEARNING
Leaders need more opportunities to train with their units to hone their skills. Leaders use After Action Reviews to improve themselves and their units. The After Action Review has existed since the 1970s and has not substantially changed in that time. New technological advancements in the last several years offer the opportunity to enhance the efficacy of the After Action Review for future leaders and units. One of these new technologies is virtual reality. Virtual reality presents trainers the ability to control all aspects of the training environment. It also enables thorough data collection and the ability to rapidly run through a scenario again.
This project sought to identify the information gaps in live training and determine whether virtual reality enables tactical learning at the individual level. Using surveys and experimentation, the team concluded that virtual reality scenarios in concert with After Action Reviews can be used for tactical learning at the individual level. Through the course of the experiment, the team also discovered that servicemembers take advantage of opportunities to improve themselves regardless of their performance.Major, United States ArmyMajor, United States ArmyCaptain, United States ArmyMajor, United States ArmyMajor, United States ArmyApproved for public release. Distribution is unlimited
Multimessenger search for sources of gravitational waves and high-energy neutrinos: Initial results for LIGO-Virgo and IceCube
The Deuterium to Hydrogen Abundance Ratio Towards a Fourth QSO: HS0105+1619
We report the measurement of the primordial D/H abundance ratio towards QSO
\object. The column density of the hydrogen in the Lyman limit
system is high, \lnhi \cmm, allowing for the deuterium to
be seen in 5 Lyman series transitions. The measured value of the D/H ratio
towards QSO \object is found to be D/H. The
metallicity of the system showing D/H is found to be solar,
indicating that the measured D/H is the primordial D/H within the measurement
errors. The gas which shows D/H is neutral, unlike previous D/H systems which
were more highly ionized. Thus, the determination of the D/H ratio becomes more
secure since we are measuring it in different astrophysical environments, but
the error is larger because we now see more dispersion between measurements.
Combined with prior measurements of D/H, the best D/H ratio is now D/H, which is 10% lower than the previous value. The new
values for the baryon to photon ratio, and baryonic matter density derived from
D/H are and \ob
respectively.Comment: Minor text and reference changes. To appear in the May 10, 2001 issue
of the Astrophysical Journa
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