143 research outputs found
Time Spent in the Military as a Moderator of Endorsement of Traditional Masculinity Ideology Predicting Relationship Satisfaction
Objective: Military culture perpetuates traditional masculine norms (Alfred, Good, & Hammer, 2014). The internalization of traditional masculinity has been linked to reduced relationship satisfaction among heterosexual couples (McGraw, 2001). The present study investigated the role of military service as moderator of the relationship between masculinity ideology and relationship satisfaction. Method: 155 heterosexual male military personnel in romantic relationships recruited from the internet reported length of service, endorsement of traditional masculinity ideology, and relationship satisfaction. Hierarchical multiple regression was used to evaluate if length of military service moderated the relationship between masculinity and relationship satisfaction. Results: Results were not consistent with previous findings that endorsement of traditional masculinity ideology predicts relationship satisfaction for men (McGraw, 2001). In addition, length of military service did not act as a moderator as hypothesized. Conclusion: Additional research is needed to clarify these results which conflict with recent findings on traditional masculinity and intimate relationships. Possible influential factors and directions for future research are explored
NICMOS Observations of the Transiting Hot Jupiter XO-1b
We refine the physical parameters of the transiting hot Jupiter planet XO-1b
and its stellar host XO-1 using HST NICMOS observations. XO-1b has a radius
Rp=1.21+/-0.03 RJup, and XO-1 has a radius Rs=0.94+/-0.02 RSun, where the
uncertainty in the mass of XO-1 dominates the uncertainty of Rp and Rs. There
are no significant differences in the XO-1 system properties between these
broad-band NIR observations and previous determinations based upon ground-based
optical observations. We measure two transit timings from these observations
with 9 s and 15 s precision. As a residual to a linear ephemeris model, there
is a 2.0 sigma timing difference between the two HST visits that are separated
by 3 transit events (11.8 days). These two transit timings and additional
timings from the literature are sufficient to rule out the presence of an Earth
mass planet orbiting in 2:1 mean motion resonance coplanar with XO-1b. We
identify and correct for poorly understood gain-like variations present in
NICMOS time series data. This correction reduces the effective noise in time
series photometry by a factor of two, for the case of XO-1.Comment: 13 pages, 8 figures, submitted to Ap
Baseline Chromatin Modification Levels May Predict Interindividual Variability in Ozone-Induced Gene Expression
Traditional toxicological paradigms have relied on factors such as age, genotype, and disease status to explain variability in responsiveness to toxicant exposure; however, these are neither sufficient to faithfully identify differentially responsive individuals nor are they modifiable factors that can be leveraged to mitigate the exposure effects. Unlike these factors, the epigenome is dynamic and shaped by an individualâs environment. We sought to determine whether baseline levels of specific chromatin modifications correlated with the interindividual variability in their ozone (O3)-mediated induction in an airâliquid interface model using primary human bronchial epithelial cells from a panel of 11 donors. We characterized the relationship between the baseline abundance of 6 epigenetic markers with established roles as key regulators of gene expressionâhistone H3 lysine 4 trimethylation (H3K4me3), H3K27 acetylation (H3K27ac), pan-acetyl H4 (H4ac), histone H3K27 di/trimethylation (H3K27me2/3), unmodified H3, and 5-hydroxymethylcytosine (5-hmC)âand the variability in the O3-induced expression of IL-8, IL-6, COX2, and HMOX1. Baseline levels of H3K4me3, H3K27me2/3, and 5-hmC, but not H3K27ac, H4ac, and total H3, correlated with the interindividual variability in O3-mediated induction of HMOX1 and COX2. In contrast, none of the chromatin modifications that we examined correlated with the induction of IL-8 and IL-6. From these findings, we propose an âepigenetic seed and soilâ model in which chromatin modification states between individuals differ in the relative abundance of specific modifications (the âsoilâ) that govern how receptive the gene is to toxicant-mediated cellular signals (the âseedâ) and thus regulate the magnitude of exposure-related gene induction
Precise Estimates of the Physical Parameters for the Exoplanet System HD-17156 Enabled by HST FGS Transit and Asteroseismic Observations
We present observations of three distinct transits of HD 17156b obtained with
the Fine Guidance Sensors (FGS) on board the Hubble Space Telescope} (HST). We
analyzed both the transit photometry and previously published radial velocities
to find the planet-star radius ratio R_p/R_s = 0.07454 +/- 0.00035, inclination
i=86.49 +0.24/-0.20 deg, and scaled semi-major axis a/R = 23.19 +0.32/-0.27.
This last value translates directly to a mean stellar density determination of
0.522 +0.021/-0.018 g cm^-3. Analysis of asteroseismology observations by the
companion paper of Gilliland et al. (2009) provides a consistent but
significantly refined measurement of the stellar mean density. We compare
stellar isochrones to this density estimate and find M_s = 1.275 +/- 0.018
M_sun and a stellar age of $3.37 +0.20/-0.47 Gyr. Using this estimate of M_s
and incorporating the density constraint from asteroseismology, we model both
the photometry and published radial velocities to estimate the planet radius
R_p= 1.0870 +/- 0.0066 Jupiter radii and the stellar radius R_s = 1.5007 +/-
0.0076 R_sun. The planet radius is larger than that found in previous studies
and consistent with theoretical models of a solar-composition gas giant of the
same mass and equilibrium temperature. For the three transits, we determine the
times of mid-transit to a precision of 6.2 s, 7.6 s, and 6.9 s, and the transit
times for HD 17156 do not show any significant departures from a constant
period. The joint analysis of transit photometry and asteroseismology presages
similar studies that will be enabled by the NASA Kepler Mission.Comment: Accepted for publication to Ap
Asteroseismology of the Transiting Exoplanet Host HD 17156 with HST FGS
Observations conducted with the Fine Guidance Sensor on Hubble Space
Telescope (HST) providing high cadence and precision time-series photometry
were obtained over 10 consecutive days in December 2008 on the host star of the
transiting exoplanet HD 17156b. During this time 10^12 photons (corrected for
detector deadtime) were collected in which a noise level of 163 parts per
million per 30 second sum resulted, thus providing excellent sensitivity to
detection of the analog of the solar 5-minute p-mode oscillations. For HD 17156
robust detection of p-modes supports determination of the stellar mean density
of 0.5301 +/- 0.0044 g/cm^3 from a detailed fit to the observed frequencies of
modes of degree l = 0, 1, and 2. This is the first star for which direct
determination of the mean stellar density has been possible using both
asteroseismology and detailed analysis of a transiting planet light curve.
Using the density constraint from asteroseismology, and stellar evolution
modeling results in M_star = 1.285 +/- 0.026 solar, R_star = 1.507 +/- 0.012
solar, and a stellar age of 3.2 +/- 0.3 Gyr.Comment: Accepted by ApJ; 16 pages, 18 figure
Catheterârelated Infection and Septicemia: Impact of Seasonality and Modifiable Practices from the DOPPS
Hemodialysis (HD) catheterârelated infection (CRI) and septicemia contribute to adverse outcomes. The impact of seasonality and prophylactic dialysis practices during highârisk periods remain unexplored. This multicenter study analyzed DOPPS data from 12,122 HD patients (from 442 facilities) to determine the association between seasonally related climatic variables and CRI and septicemia. Climatic variables were determined by linkage to National Climatic Data Center of National Oceanic and Atmospheric Administration data. Catheter care protocols were examined to determine if they could mitigate infection risk during highârisk seasons. Survival models were used to estimate the adjusted hazard ratio (AHR) of septicemia by season and by facility catheter dressing protocol. The overall catheterârelated septicemia rate was 0.47 per 1000 catheter days. It varied by season, with an AHR for summer of 1.46 (95% CI: 1.19â1.80) compared with winter. Septicemia was associated with temperature (AHR = 1.07; 95% CI: 1.02â1.13; p  < 0.001). Dressing protocols using chlorhexidine (AHR of septicemia = 0.55; 95% CI: 0.39â0.78) were associated with fewest episodes of CRI or septicemia. Higher catheterârelated septicemia in summer may be due to seasonal conditions (e.g., heat, perspiration) that facilitate bacterial growth and compromise protective measures. Extra vigilance and use of chlorhexidineâbased dressing protocols may provide prophylaxis against CRI and septicemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102686/1/sdi12141.pd
Cytoplasmic BK\u3csub\u3eCa\u3c/sub\u3e channel intron-containing mRNAs contribute to the intrinsic excitability of hippocampal neurons
High single-channel conductance K+ channels, which respond jointly to membrane depolarization and micromolar concentrations of intracellular Ca2+ ions, arise from extensive cell-specific alternative splicing of pore-forming α-subunit mRNAs. Here, we report the discovery of an endogenous BKCa channel α-subunit intron-containing mRNA in the cytoplasm of hippocampal neurons. This partially processed mRNA, which comprises â10% of the total BKCa channel α-subunit mRNAs, is distributed in a gradient throughout the somatodendritic space. We selectively reduced endogenous cytoplasmic levels of this intron-containing transcript by RNA interference without altering levels of the mature splice forms of the BKCa channel mRNAs. In doing so, we could demonstrate that changes in a unique BKCa channel α-subunit introncontaining splice variant mRNA can greatly impact the distribution of the BKCa channel protein to dendritic spines and intrinsic firing properties of hippocampal neurons. These data suggest a new regulatory mechanism for modulating the membrane properties and ion channel gradients of hippocampal neurons
A novel pH-sensitive liposome formulation containing oleyl alcohol
AbstractpH-sensitive liposomes are designed to undergo acid-triggered destabilization. First generation pH-sensitive liposomes, based on the cone-shaped lipid dioleoylphosphatidylethanolamine (DOPE), have been shown to lose fusogenicity in the presence of serum. Here, we report the design and evaluation of novel serum-resistant pH-sensitive liposome formulations that are based on the composition of egg phosphatidylcholine (PC), cholesteryl hemisuccinate (CHEMS), oleyl alcohol (OAlc), and Tween-80 (T-80). When loaded with the fluorescent probe calcein, these liposomes exhibited excellent stability at pH 7.4 and underwent rapid destabilization upon acidification as shown by calcein dequenching and particle size increase. Adjusting the mole percentages of T-80 and OAlc in the formulation could regulate the stability and pH-sensitive properties of these liposomes. Liposomes with a higher T-80 content exhibited greater stability but were less sensitive to acid-induced destabilization. Meanwhile, formulations with a higher OAlc content exhibited greater content release in response to low pH. The pH-triggered liposomal destabilization did not produce membrane fusion according to an octadecylrhodamine B chloride (R18) lipid-mixing assay. Compared to DOPE-based pH-sensitive liposomes, the above formulations showed much better retention of their pH-sensitive properties in the presence of 10% serum. These liposomes were then evaluated for intracellular delivery of entrapped cytosine-ÎČ-d-arabinofuranoside (araC) in KB human oral cancer cells, which have elevated folate receptor (FR) expression. The FR, which is amplified in many types of human tumors, has been shown to mediate the internalization of folate-derivatized liposomes into an acidic intracellular compartment. FR-targeted OAlc-based pH-sensitive liposomes, entrapping 200 mM araC, showed âŒ17-times greater FR-dependent cytotoxicity in KB cells compared to araC delivered via FR-targeted non-pH-sensitive liposomes. These data indicated that pH-sensitive liposomes based on OAlc, combined with FR-mediated targeting, are promising delivery vehicles for membrane impermeable therapeutic agents
Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope
Exoplanetary transmission spectroscopy in the near-infrared using the Hubble Space Telescope (HST) NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial scanning with HST/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 spectroscopy of the giant planets HD 209458b and XO-1b in transit, using spatial scanning mode for maximum photon-collecting efficiency. We introduce an analysis technique that derives the exoplanetary transmission spectrum without the necessity of explicitly decorrelating instrumental effects, and achieves nearly photon-limited precision even at the high flux levels collected in spatial scan mode. Our errors are within 6% (XO-1) and 26% (HD 209458b) of the photon-limit at a resolving power of λ/Ύλ ~ 70, and are better than 0.01% per spectral channel. Both planets exhibit water absorption of approximately 200 ppm at the water peak near 1.38 ÎŒm. Our result for XO-1b contradicts the much larger absorption derived from NICMOS spectroscopy. The weak water absorption we measure for HD 209458b is reminiscent of the weakness of sodium absorption in the first transmission spectroscopy of an exoplanet atmosphere by Charbonneau et al. Model atmospheres having uniformly distributed extra opacity of 0.012 cm2 gâ1 account approximately for both our water measurement and the sodium absorption. Our results for HD 209458b support the picture advocated by Pont et al. in which weak molecular absorptions are superposed on a transmission spectrum that is dominated by continuous opacity due to haze and/or dust. However, the extra opacity needed for HD 209458b is grayer than for HD 189733b, with a weaker Rayleigh component
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