5,619 research outputs found
Determiniation of Flouride Ion in Well Waters of Eastwood School District, Wood, County, Ohio
Author Institution: Eastwood Local Schools ; Chemistry Department, University of ToledoThe purpose of this investigation was to determine the amount of fluoride ion present in the well water of Eastwood Local School District, Wood County, Ohio. Ninety-two water samples were gathered from separate wells in the district and analyzed for fluoride content. Fluoride determination was made with a fluoride ion-selective electrode using a direct potentiometric method. pH measurements were also made upon the samples. Fluoride levels were found to range from 0.6 to 3.8 parts per million. pH measurements varied from 6.91 to 8.30
Transcriptomes of parents identify parenting strategies and sexual conflict in a subsocial beetle
This work was funded by UK NERC grants to M.G.R. and A.J.M. an NERC studentship to D.J.P. the University of Georgia and a US NSF grant to A.J.M. and M.G.R.Parenting in the burying beetle Nicrophorus vespilloides is complex and, unusually, the sex and number of parents that can be present is flexible. Such flexibility is expected to involve specialized behaviour by the two sexes under biparental conditions. Here, we show that offspring fare equally well regardless of the sex or number of parents present. Comparing transcriptomes, we find a largely overlapping set of differentially expressed genes in both uniparental and biparental females and in uniparental males including vitellogenin, associated with reproduction, and takeout, influencing sex-specific mating and feeding behaviour. Gene expression in biparental males is similar to that in non-caring states. Thus, being ‘biparental’ in N. vespilloides describes the family social organization rather than the number of directly parenting individuals. There was no specialization; instead, in biparental families, direct male parental care appears to be limited with female behaviour unchanged. This should lead to strong sexual conflict.Publisher PDFPeer reviewe
Health Care Use and Costs Among Patients With Nonalcoholic Steatohepatitis With Advanced Fibrosis Using the Fibrosis-4 Score
Limited evidence exists on the clinical and economic burden of advanced fibrosis in patients with nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) due to the invasiveness of liver biopsies for accurately staging liver disease. The fibrosis-4 (FIB-4) score allows for noninvasive assessment of liver fibrosis by using clinical and laboratory data alone. This study aimed to characterize the comorbidity burden, health care resource use (HCRU), and costs among patients with NAFLD/NASH with FIB-4-defined F3 (bridging fibrosis) and F4 (compensated cirrhosis) fibrosis. Using the Optum Research Database, a retrospective cohort study was conducted among 251,725 commercially insured adult patients with ≥1 NAFLD/NASH diagnosis from January 1, 2008, to August 31, 2016, and laboratory data required to calculate FIB-4 scores. Five criteria using varying FIB-4 score cutoffs were identified based on expert clinical opinion and published literature. Date of the first valid FIB-4 score marked the index date. Mean annual HCRU and costs were calculated during the pre-index and post-index periods. The prevalence of FIB-4-based F3 and F4 fibrosis was 0.40%-2.72% and 1.03%-1.61%, respectively. Almost 50% of patients identified with FIB-4-based F3 or F4 had type 2 diabetes, cardiovascular disease, or renal impairment. Total all-cause health care costs increased significantly from pre-index to post-index for patients with FIB-4-based F3 fibrosis across most criteria (17%-29% increase) and patients with FIB-4-based F4 fibrosis across all criteria (47%-48% increase). Inpatient costs were the primary drivers of this increment
Cumulative mutagenesis of the basic residues in the 201-218 region of insulin-like growth factor (IGF)-binding protein-5 results in progressive loss of both IGF-I binding and inhibition of IGF-I biological action
We have reported previously that mutation of two conserved nonbasic amino acids (G203 and Q209) within the highly basic 201–218 region in the C-terminal domain of IGF-binding protein-5 (IGFBP-5) decreases binding to IGFs. This study reveals that cumulative mutagenesis of the 10 basic residues in this region, to create the C-Term series of mutants, ultimately results in a 15-fold decrease in the affinity for IGF-I and a major loss in heparin binding. We examined the ability of mutants to inhibit IGF-mediated survival of MCF-7 cells and were able to demonstrate that this depended not only upon the affinity for IGF-I, but also the kinetics of this interaction, because IGFBP-5 mutants with similar affinity constants (KD) values, but with different association (Ka) and dissociation (Kd) rate values, had markedly different inhibitory properties. In contrast, the affinity for IGF-I provided no predictive value in terms of the ability of these mutants to enhance IGF action when bound to the substratum. Instead, these C-Term mutants appeared to enhance the actions of IGF-I by a combination of increased dissociation of IGF-IGFBP complexes from the substratum, together with dissociation of IGF-I from IGFBP-5 bound to the substratum. These effects of the IGFBPs were dependent upon binding to IGF-I, because a non-IGF binding mutant (N-Term) was unable to inhibit or enhance the actions of IGF-I. These results emphasize the importance of the kinetics of association/dissociation in determining the enhancing or inhibiting effects of IGFBP-5 and demonstrate the ability to generate an IGFBP-5 mutant with exclusively IGF-enhancing activity
Long-range vibrational dynamics are directed by Watson-Crick base-pairing in duplex DNA
Ultrafast two-dimensional infrared (2D-IR) spectroscopy of a 15-mer A-T DNA duplex in solution has revealed structure-dependent vibrational coupling and energy transfer processes linking bases with the sugar-phosphate backbone. Duplex melting induces significant changes in the positions of off-diagonal peaks linking carbonyl and ring-stretching vibrational modes of the adenine and thymine bases with vibrations of the phosphate group and phosphodiester linkage. These indicate that Watson-Crick hydrogen bonding and helix formation leads to a unique vibrational coupling arrangement of base vibrational modes with those of the phosphate unit. Based on observations from time-resolved 2D-IR data, we conclude that rapid energy transfer processes occur between base and backbone, mediated by additional modes located on the deoxyribose moiety within the same nucleotide. These relaxation dynamics are insensitive to duplex melting, showing that efficient intramo-lecular energy relaxation to the solvent via the phosphate groups is the key to excess energy dissipation in both single and double-stranded DNA
Emission-line stars discovered in the UKST H-alpha survey of the Large Magellanic Cloud; Part 1: Hot stars
We present new, accurate positions, spectral classifications, radial and
rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes
for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud
which include 469 new discoveries. Candidate emission line stars were
discovered using a deep, high resolution H-alpha map of the central 25 deg2 of
the LMC obtained by median stacking a dozen 2 hour H-alpha exposures taken with
the UK Schmidt Telescope. Spectroscopic follow-up observations on the AAT,
UKST, VLT, the SAAO 1.9m and the MSSSO 2.3m telescope have established the
identity of these faint sources down to magnitude R~23 for H-alpha (4.5 x
10^-17 ergs cm^2 s^-1 Ang). Confirmed emission-line stars have been assigned an
underlying spectral classification through cross-correlation against 131
absorption line template spectra covering the range O1 to F8. We confirm 111
previously identified emission line stars and 64 previously known variable
stars with spectral types hotter than F8. The majority of hot stars identified
(518 stars or 89%) are class B. Of all the hot emission-line stars in classes
B-F, 130 or 22% are type B[e], characterised by the presence of forbidden
emission lines such as [SII], [NII] and [OII]. We report on the physical
location of these stars with reference to possible contamination from ambient
HII emission. Along with flux calibration of the H-alpha emission we provide
the first H-alpha luminosity function for selected sub-samples after correction
for any possible nebula or ambient contamination. We find a moderate
correlation between the intensity of H-alpha emission and the V magnitude of
the central star based on SuperCOSMOS magnitudes and OGLE-II photometry where
possible. Cool stars from classes G-S, with and without strong H-alpha
emission, will be the focus of part 2 in this series.Comment: 24 pages (main paper) 36 figures, 6 tables; Appendix Tables: 22
pages, MNRAS, 201
SPITZER SAGE Observations of Large Magellanic Cloud Planetary Nebulae
We present IRAC and MIPS images and photometry of a sample of previously
known planetary nebulae (PNe) from the SAGE survey of the Large Magellanic
Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in
the survey field, 185 objects were detected in at least two of the IRAC bands,
and 161 detected in the MIPS 24 micron images. Color-color and color-magnitude
diagrams are presented using several combinations of IRAC, MIPS, and 2MASS
magnitudes. The location of an individual PN in the color-color diagrams is
seen to depend on the relative contributions of the spectral components which
include molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), infrared
forbidden line emission from the ionized gas, warm dust continuum, and emission
directly from the central star. The sample of LMC PNe is compared to a number
of Galactic PNe and found to not significantly differ in their position in
color-color space. We also explore the potential value of IR PNe luminosity
functions (LFs) in the LMC. IRAC LFs appear to follow the same functional form
as the well-established [O III] LFs although there are several PNe with
observed IR magnitudes brighter than the cut-offs in these LFs.Comment: 18 pages, 10 figures, 3 tables, to be published in the Astronomical
Journal. Additional online data available at
http://www.cfa.harvard.edu/irac/publications
Predictors of British Isles Lupus Assessment Group-based outcomes in patients with systemic lupus erythematosus:Analysis from the Systemic Lupus International Collaborating Clinics Inception Cohort
BackgroundWe aimed to identify factors associated with a significant reduction in SLE disease activity over 12 months assessed by the BILAG Index.MethodsIn an international SLE cohort, we studied patients from their 'inception enrolment' visit. We also defined an 'active disease' cohort of patients who had active disease similar to that needed for enrolment into clinical trials. Outcomes at 12 months were; Major Clinical Response (MCR: reduction to classic BILAG C in all domains, steroid dose of ≤7.5 mg and SLEDAI ≤ 4) and 'Improvement' (reduction to ≤1B score in previously active organs; no new BILAG A/B; stable or reduced steroid dose; no increase in SLEDAI). Univariate and multivariate logistic regression with Least Absolute Shrinkage and Selection Operator (LASSO) and cross-validation in randomly split samples were used to build prediction models.Results'Inception enrolment' (n = 1492) and 'active disease' (n = 924) patients were studied. Models for MCR performed well (ROC AUC = .777 and .732 in the inception enrolment and active disease cohorts, respectively). Models for Improvement performed poorly (ROC AUC = .574 in the active disease cohort). MCR in both cohorts was associated with anti-malarial use and inversely associated with active disease at baseline (BILAG or SLEDAI) scores, BILAG haematological A/B scores, higher steroid dose and immunosuppressive use.ConclusionBaseline predictors of response in SLE can help identify patients in clinic who are less likely to respond to standard therapy. They are also important as stratification factors when designing clinical trials in order to better standardize overall usual care response rates
On the Formation of Silacyclopropenylidene (c-SiC2H2) and its Role in the Organosilicon Chemistry in the Interstellar Medium
Organosilicon species such as silicon carbide and silicon dicarbide are considered as key molecular building blocks in the chemical evolution of the interstellar medium and are associated with the formation of silicon-carbide dust grains in the outflow of circumstellar envelopes of carbon-rich asymptotic giant branch (AGB) stars. However, the formation mechanisms of even the simplest silicon-bearing organic molecules have remained elusive for decades. Here, we demonstrate in crossed molecular beam experiments combined with ab initio calculations that the silacyclopropenylidene molecule (c-SiCH) can be synthesized in the gas phase under single-collision conditions via the reaction of the silylidyne radical (SiH) with acetylene (CH). This system denotes the simplest representative of a previously overlooked reaction class, in which the formation of an organosilicon molecule can be initiated via barrierless and exoergic reactions of silylidyne radicals with hydrocarbon molecules in circumstellar envelopes of evolved carbon stars such as IRC+10216. Since organosilicon molecules like silacyclopropenylidene can be eventually photolyzed to carbon-silicon clusters such as silicon dicarbide (c-SiC), silacyclopropenylidene might even represent the missing link between simple molecular precursors and silicon-carbide-rich interstellar grains.Interstellar matter and star formatio
- …