Clinical Practice Variability in Temperature Correction of Arterial Blood Gas Measurements and Outcomes in Hypothermia-Treated Patients After Cardiac Arrest

Mechanical ventilation in patients treated with mild therapeutic hypothermia (MTH) for the postcardiac arrest syndrome may be challenging given changes in solubility of arterial blood gases (ABGs) with cooling. Whether ABG measurements should be temperature corrected (TC) remain unknown. We sought to describe practice variability in TC at a single institution and explored the association between TC and neurological outcome. We conducted a retrospective cohort study reviewing electronic health records of all patients treated with MTH after cardiac arrest. We examined whether the percentage of TC ABGs relative to total number of ABGs drawn for each subject during hypothermia was associated with the neurological outcome at hospital discharge and 6?12-month follow-up. The cerebral performance category of 1?2 was defined as a favorable outcome in the logistic regression models. 1223 ABGs were obtained during MTH on 122 subjects over 6 years. TC was never used in 72 subjects (59%; no TC group), made available in 1?74% of ABGs in 17 subjects (14%; intermediate TC group), and made available in ≥75% of ABGs in 33 subjects (27%; mostly TC group). Groups differed in the proportion of subjects with shockable presenting rhythms (47% vs. 47% vs. 76%, p=0.02) and admitting ICU (p=0.005). Favorable 6-month outcomes were more common in the mostly TC than no TC group (48% vs. 25%; OR [95% CI]: 2.9 [1.2?7.1]), but not after adjustment (OR 1.5, 95% CI 0.33?6.9). There was substantial practice variability in the temperature correction strategy. Availability of temperature-corrected ABGs was not associated with improved neurological outcomes after adjusting for covariates.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140256/1/ther.2014.0029.pd

The Evolution of the Fractions of Quiescent and Star-forming Galaxies as a Function of Stellar Mass Since z=3: Increasing Importance of Massive, Dusty Star-forming Galaxies in the Early Universe

Using the UltraVISTA DR1 and 3D-HST catalogs, we construct a stellar-mass-complete sample, unique for its combination of surveyed volume and depth, to study the evolution of the fractions of quiescent galaxies, moderately unobscured star-forming galaxies, and dusty star-forming galaxies as a function of stellar mass over the redshift interval $0.2 \le z \le 3.0$. We show that the role of dusty star-forming galaxies within the overall galaxy population becomes more important with increasing stellar mass, and grows rapidly with increasing redshift. Specifically, dusty star-forming galaxies dominate the galaxy population with $\log{(M_{\rm star}/M_{\odot})} \gtrsim 10.3$ at $z\gtrsim2$. The ratio of dusty and non-dusty star-forming galaxies as a function of stellar mass changes little with redshift. Dusty star-forming galaxies dominate the star-forming population at $\log{(M_{\rm star}/M_{\odot})} \gtrsim 10.0-10.5$, being a factor of $\sim$3-5 more common, while unobscured star-forming galaxies dominate at $\log{(M_{\rm star}/M_{\odot})} \lesssim 10$. At $\log{(M_{\rm star}/M_{\odot})} > 10.5$, red galaxies dominate the galaxy population at all redshift $z<3$, either because they are quiescent (at late times) or dusty star-forming (in the early universe).Comment: 7 pages, 4 figures, 1 table. Accepted by Astrophysical Journal Letters after minor revisio

Electrically driven photon emission from individual atomic defects in monolayer WS2.

Quantum dot-like single-photon sources in transition metal dichalcogenides (TMDs) exhibit appealing quantum optical properties but lack a well-defined atomic structure and are subject to large spectral variability. Here, we demonstrate electrically stimulated photon emission from individual atomic defects in monolayer WS2 and directly correlate the emission with the local atomic and electronic structure. Radiative transitions are locally excited by sequential inelastic electron tunneling from a metallic tip into selected discrete defect states in the WS2 bandgap. Coupling to the optical far field is mediated by tip plasmons, which transduce the excess energy into a single photon. The applied tip-sample voltage determines the transition energy. Atomically resolved emission maps of individual point defects closely resemble electronic defect orbitals, the final states of the optical transitions. Inelastic charge carrier injection into localized defect states of two-dimensional materials provides a powerful platform for electrically driven, broadly tunable, atomic-scale single-photon sources

PAID TO PUMP: How a tax credit could discourage conservation of the High Plains Aquifer

In 1965’s United States v. Shurbet case, an irrigator from Texas asserted his claim for a depletion tax deduction for groundwater pumped from the High Plains Aquifer. He argued that the unique conditions of the southern High Plains region - a plateau where the shallow aquifer is recharged only through precipitation at a slow rate - meant the groundwater resource would be depleted in time. The state argued that groundwater was not fundamentally an exhaustible natural deposit, but the Supreme Court concluded the tax deduction was appropriate given the “peculiar” conditions in the area. It was stated the decision was not meant to establish a precedent regarding cost depletion of groundwater. The findings of the Shurbet case were intended to be limited to the southern High Plains region. However, in a 1980 lawsuit against the IRS, the Gigot brothers of Kansas sought to expand the deduction to allow depletion of the aquifer beneath their 30,000 acre farm in Kansas. The case was settled in the district court with a ruling allowing the brothers’ deductions to continue, thereby extending the Shurbet decision to include all landowners extracting from the approximately 174,000 square miles of land overlying the High Plains Aquifer. Currently, the estimated value of the credit is highest in parts of northern Texas, eastern Colorado, western Kansas, and south central Nebraska

Characterizing the Cool KOIs. VI. H- and K-band Spectra of Kepler M Dwarf Planet-Candidate Hosts

We present H- and K-band spectra for late-type Kepler Objects of Interest (the "Cool KOIs"): low-mass stars with transiting-planet candidates discovered by NASA's Kepler Mission that are listed on the NASA Exoplanet Archive. We acquired spectra of 103 Cool KOIs and used the indices and calibrations of Rojas-Ayala et al. to determine their spectral types, stellar effective temperatures and metallicities, significantly augmenting previously published values. We interpolate our measured effective temperatures and metallicities onto evolutionary isochrones to determine stellar masses, radii, luminosities and distances, assuming the stars have settled onto the main-sequence. As a choice of isochrones, we use a new suite of Dartmouth predictions that reliably include mid-to-late M dwarf stars. We identify five M4V stars: KOI-961 (confirmed as Kepler 42), KOI-2704, KOI-2842, KOI-4290, and the secondary component to visual binary KOI-1725, which we call KOI-1725 B. We also identify a peculiar star, KOI-3497, which has a Na and Ca lines consistent with a dwarf star but CO lines consistent with a giant. Visible-wavelength adaptive optics imaging reveals two objects within a 1 arc second diameter; however, the objects' colors are peculiar. The spectra and properties presented in this paper serve as a resource for prioritizing follow-up observations and planet validation efforts for the Cool KOIs, and are all available for download online using the "data behind the figure" feature.Comment: Accepted for publication in the Astrophysical Journal Supplement Series (ApJS). Data and table are available in the sourc

Leveraging the Health and Retirement Study To Advance Palliative Care Research

Background: The critical need to expand and develop the palliative care evidence base was recently highlighted by the Journal of Palliative Medicine's series of articles describing the Research Priorities in Geriatric Palliative Care. The Health and Retirement Study (HRS) is uniquely positioned to address many priority areas of palliative care research. This nationally representative, ongoing, longitudinal study collects detailed survey data every 2 years, including demographics, health and functional characteristics, information on family and caregivers, and personal finances, and also conducts a proxy interview after each subject's death. The HRS can also be linked with Medicare claims data and many other data sources, e.g., U.S. Census, Dartmouth Atlas of Health Care. Setting: While the HRS offers innumerable research opportunities, these data are complex and limitations do exist. Therefore, we assembled an interdisciplinary group of investigators using the HRS for palliative care research to identify the key palliative care research gaps that may be amenable to study within the HRS and the strengths and weaknesses of the HRS for each of these topic areas. Conclusion: In this article we present the work of this group as a potential roadmap for investigators contemplating the use of HRS data for palliative care research.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140117/1/jpm.2013.0648.pd

Effect of Intubation Timing on the Outcome of Patients With Severe Respiratory Distress Secondary to COVID-19 Pneumonia.

Background: The optimal timing of intubation for critically ill patients with severe respiratory illness remains controversial among healthcare providers. The coronavirus disease 2019 (COVID-19) pandemic has raised even more questions about when to implement this life-saving therapy. While one group of providers prefers early intubation for patients with respiratory distress because these patients may deteriorate rapidly without it, other providers believe that intubation should be delayed or avoided because of its associated risks including worse outcomes. Research question: Our objective was to assess whether the timing of intubation in patients with severe COVID-19 pneumonia was associated with differences in mortality or other outcomes. Study design and methods: This was a single-center retrospective observational cohort study. We analyzed outcomes of patients who were intubated secondary to COVID-19 pneumonia between March 13, 2020, and December 12, 2020, at Henry Ford Hospital in Detroit, Michigan. Patients were categorized into two groups: early intubated (intubated within 24 hours of the onset of severe respiratory distress) and late intubated (intubated after 24 hours of the onset of severe respiratory distress). Demographics, comorbidities, respiratory rate oxygenation (ROX) index, sequential organ failure assessment (SOFA) score, and treatment received were compared between groups. The primary outcome was mortality. Secondary outcomes were ventilation time, intensive care unit stay, hospital length of stay, and discharge disposition. Post hoc and Kaplan-Meier survival analyses were performed. Results: A total of 110 patients were included: 55 early intubated and 55 late intubated. We did not observe a significant difference in overall mortality between the early intubated (43%) and the late intubated groups (53%) (p = 0.34). There was no statistically significant difference in patients\u27 baseline characteristics including SOFA scores (the early intubation group had a mean score of 7.5 compared to 6.7 in the late intubation group). Based on the ROX index, the early intubation group had significantly more patients with a reduced risk of intubation (45%) than the late group (27%) (p = 0.029). The early intubation group was treated with a high-flow nasal cannula at a significantly lower rate (47%) than the late intubation group (83%) (p \u3c 0.001). Significant differences in patient baseline characteristics, treatment received, and other outcomes were not observed. Post hoc analysis adjusting for SOFA score between 0 and 9 revealed significantly higher mortality in the late intubation group (49%) than in the early intubation group (26%) (p = 0.03). Patients in the 0 to 9 SOFA group who were intubated later had 2.7 times the odds of dying during hospital admission compared to patients who were intubated early (CI, 1.09-6.67). Interpretation: The timing of intubation for patients with severe COVID-19 pneumonia was not significantly associated with overall mortality or other patient outcomes. However, within the subgroup of patients with SOFA scores of 9 or lower at the time of intubation, patients intubated after 24 hours of the onset of respiratory distress had a higher risk of death than those who were intubated within 24 hours of respiratory distress. Thus, patients with COVID-19 pneumonia who are not at a high level of organ dysfunction may benefit from early mechanical ventilation

New M, L, and T Dwarf Companions to Nearby Stars from the Wide-field Infrared Survey Explorer

We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar

The pattern of xylan acetylation suggests xylan may interact with cellulose microfibrils as a twofold helical screw in the secondary plant cell wall of Arabidopsis thaliana.

The interaction between xylan and cellulose microfibrils is important for secondary cell wall properties in vascular plants; however, the molecular arrangement of xylan in the cell wall and the nature of the molecular bonding between the polysaccharides are unknown. In dicots, the xylan backbone of β-(1,4)-linked xylosyl residues is decorated by occasional glucuronic acid, and approximately one-half of the xylosyl residues are O-acetylated at C-2 or C-3. We recently proposed that the even, periodic spacing of GlcA residues in the major domain of dicot xylan might allow the xylan backbone to fold as a twofold helical screw to facilitate alignment along, and stable interaction with, cellulose fibrils; however, such an interaction might be adversely impacted by random acetylation of the xylan backbone. Here, we investigated the arrangement of acetyl residues in Arabidopsis xylan using mass spectrometry and NMR. Alternate xylosyl residues along the backbone are acetylated. Using molecular dynamics simulation, we found that a twofold helical screw conformation of xylan is stable in interactions with both hydrophilic and hydrophobic cellulose faces. Tight docking of xylan on the hydrophilic faces is feasible only for xylan decorated on alternate residues and folded as a twofold helical screw. The findings suggest an explanation for the importance of acetylation for xylan-cellulose interactions, and also have implications for our understanding of cell wall molecular architecture and properties, and biological degradation by pathogens and fungi. They will also impact strategies to improve lignocellulose processing for biorefining and bioenergy.The work conducted by TT and NN was supported by a grant from the BBSRC: BB/G016240/1 BBSRC Sustainable Energy Centre Cell Wall Sugars Programme (BSBEC) to PD and DNB. The work of PD was supported by the European Community’s Seventh Framework Programme SUNLIBB (FP7/2007-2013) under the grant agreement #251132. The NMR facility infrastructure was supported by the BBSRC and the Wellcome Trust. TCFG thanks CNPq (Brazil) for a graduate fellowship (grant # 140978/2009-7). MSS thanks CEPROBIO (grant # 490022/2009- 0) and FAPESP for funding (grant #2013/08293-7).This is the accepted version of the following article: "Busse-Wicher, M; Gomes, T.C.F; Tryfona, T; Nikolovski, N; Stott, K; Grantham, N.J; Bolam, D.N; Skaf, M.S; Dupree, P. (2014) "The pattern of xylan acetylation suggests xylan may interact with cellulose microfibrils as a two-fold helical screw in the secondary plant cell wall of Arabidopsis thaliana." The Plant Journal. Accepted article [electronic] 10.1111/tpj.12575", which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/tpj.12575/abstrac