A Cepheid Distance to NGC 4603 in Centaurus

In an attempt to use Cepheid variables to determine the distance to the Centaurus cluster, we have obtained images of NGC 4603 with the Hubble Space Telescope on 9 epochs using WFPC2 and the F555W and F814W filters. This galaxy has been suggested to lie within the ``Cen30'' portion of the cluster and is the most distant object for which this method has been attempted. Previous distance estimates for Cen30 have varied significantly and some have presented disagreements with the peculiar velocity predicted from redshift surveys, motivating this investigation. Using our observations, we have found 61 candidate Cepheid variable stars; however, a significant fraction of these candidates are likely to be nonvariable stars whose magnitude measurement errors happen to fit a Cepheid light curve of significant amplitude for some choice of period and phase. Through a maximum likelihood technique, we determine that we have observed 43 +/- 7 real Cepheids and that NGC 4603 has a distance modulus of 32.61 +0.11/-0.10 (random, 1 sigma) +0.24/-0.25 (systematic, adding in quadrature), corresponding to a distance of 33.3 Mpc. This is consistent with a number of recent estimates of the distance to NGC 4603 or Cen30 and implies a small peculiar velocity consistent with predictions from the IRAS 1.2 Jy redshift survey if the galaxy lies in the foreground of the cluster.Comment: Accepted for publication in the Astrophysical Journal. 17 pages with 17 embedded figures and 3 tables using emulateapj.sty. Additional figures and images may be obtained from http://astro.berkeley.edu/~marc/n4603

The flexibility and dynamics of protein disulphide-isomerase

We have studied the mobility of the multi-domain folding catalyst, protein disulphide-isomerase (PDI), by a coarse-graining approach based on exibility. We analyse our simulations of yeast PDI (yPDI) using measures of backbone movement, relative positions and orientations of domains, and distances between functional sites. We nd that there is interdomain exibility at every interdomain junction but these show very di erent characteristics. The extent of interdomain exibility is such that yPDI's two active sites can approach much more closely than is found in crystal structures | and indeed hinge motion to bring these sites into proximity is the lowest energy normal mode of motion of the protein. The exibility predicted for yPDI (based on one structure) includes the other known conformation of yPDI and is consistent with (i) the mobility observed experimentally for mammalian PDI and (ii) molecular dynamics. We also observe intradomain exibility and clear di erences between the domains in their propensity for internal motion. Our results suggest that PDI exibility enables it to interact with many di erent partner molecules of widely di erent sizes and shapes, and highlights considerable similarities of yPDI and mammalian PDI

Oral ondansetron administration to nondehydrated children with diarrhea and associated vomiting in emergency departments in Pakistan: A randomized controlled trial

Study objective: We determine whether single-dose oral ondansetron administration to children with vomiting as a result of acute gastroenteritis without dehydration reduces administration of intravenous fluid rehydration.Methods: In this 2-hospital, double-blind, placebo-controlled, emergency department–based, randomized trial conducted in Karachi Pakistan, we recruited children aged 0.5 to 5.0 years, without dehydration, who had diarrhea and greater than or equal to 1 episode of vomiting within 4 hours of arrival. Patients were randomly assigned (1:1), through an Internet-based randomization service using a stratified variable-block randomization scheme, to single-dose oral ondansetron or placebo. The primary endpoint was intravenous rehydration (administration of 20 mL/kg of an isotonic fluid during 4 hours) within 72 hours of randomization.Results: Participant median age was 15 months (interquartile range 10 to 26) and 59.4% (372/626) were male patients. Intravenous rehydration use was 12.1% (38/314) and 11.9% (37/312) in the placebo and ondansetron groups, respectively (odds ratio 0.98; 95% confidence interval [CI] 0.60 to 1.61; difference 0.2%; 95% CI of the difference –4.9% to 5.4%). Bolus fluid administration occurred within 72 hours of randomization in 10.8% (34/314) and 10.3% (27/312) of children administered placebo and ondansetron, respectively (odds ratio 0.95; 95% CI 0.56 to 1.59). A multivariable regression model fitted with treatment group and adjusted for antiemetic administration, antibiotics, zinc prerandomization, and vomiting frequency prerandomization yielded similar results (odds ratio 0.91; 95% CI 0.55 to 1.53). There was no interaction between treatment group and age, greater than or equal to 3 stools in the preceding 24 hours, or greater than or equal to 3 vomiting episodes in the preceding 24 hours.Conclusion: Oral administration of a single dose of ondansetron did not result in a reduction in intravenous rehydration use. In children without dehydration, ondansetron does not improve clinical outcomes

Data for 'Something in the way she moves': the functional significance of flexibility in the multiple roles of protein disulfide isomerase (PDI)

Protein disulfide isomerase (PDI) has diverse functions in the endoplasmic reticulum as catalyst of redox transfer, disulfide isomerization and oxidative protein folding, as molecular chaperone and in multi-subunit complexes. It interacts with an extraordinarily wide range of substrate and partner proteins, but there is only limited structural information on these interactions. Extensive evidence on the flexibility of PDI in solution is not matched by any detailed picture of the scope of its motion. A new rapid method for simulating the motion of large proteins provides detailed molecular trajectories for PDI demonstrating extensive changes in the relative orientation of its four domains, great variation in the distances between key sites and internal motion within the core ligand-binding domain. The review shows that these simulations are consistent with experimental evidence and provide insight into the functional capabilities conferred by the extensive flexible motion of PDI

The Non-SUSY Baryonic Branch: Soft Supersymmetry Breaking of N=1 Gauge Theories

We study a non-supersymmetric deformation of the field theory dual to the baryonic branch of Klebanov-Strassler. Using a combination of analytical (series expansions) and numerical methods we construct non-supersymmetric backgrounds that smoothly interpolate between the desired UV and IR behaviors. We calculate various observables of the field theory and propose a picture of soft breaking by gaugino masses that is consistent with the various calculations on the string side.Comment: 32 pages plus many appendixes. One figur

Do we really need Confidence Intervals in the new statistics?

This paper compares the use of confidence intervals (CIs) and a sensitivity analysis called the number needed to disturb (NNTD), in the analysis of research findings expressed as ‘effect’ sizes. Using 1,000 simulations of randomised trials with up to 1,000 cases in each, the paper shows that both approaches are very similar in outcomes, and each one is highly predictable from the other. CIs are supposed to be a measure of likelihood or uncertainty in the results, showing a range of possible effect sizes that could have been produced by random sampling variation alone. NNTD is supposed to be a measure of the robustness of the effect size to any variation, including that produced by missing data. Given that they are largely equivalent and interchangeable under the conditions tested here, the paper suggests that both are really measures of robustness. It concludes that NNTD is to be preferred because it requires many fewer assumptions, is more tolerant of missing data, is easier to explain, and directly addresses the key question of whether the underlying effect size is zero or not

The Absolute Magnitude of RRc Variables From Statistical Parallax

We present the first definitive measurement of the absolute magnitude of RR Lyrae c-type variable stars (RRc) determined purely from statistical parallax. We use a sample of 247 RRc selected from the All Sky Automated Survey (ASAS) for which high-quality light curves, photometry and proper motions are available. We obtain high-resolution echelle spectra for these objects to determine radial velocities and abundances as part of the Carnegie RR Lyrae Survey (CARRS). We find that M_(V,RRc) = 0.52 +/- 0.11 at a mean metallicity of [Fe/H] = -1.59. This is to be compared with previous estimates for RRab stars (M_(V,RRab) = 0.75 +/- 0.13 and the only direct measurement of an RRc absolute magnitude (RZ Cephei, M_(V, RRc) = 0.27 +/- 0.17). We find the bulk velocity of the halo to be (W_pi, W_theta, W_z) = (10.9,34.9,7.2) km/s in the radial, rotational and vertical directions with dispersions (sigma_(W_pi), sigma_(W_theta), sigma_(W_z)) = (154.7, 103.6, 93.8) km/s. For the disk, we find (W_pi, W_theta, W_z) = (8.5, 213.2, -22.1) km/s with dispersions (sigma_(W_pi), sigma_(W_theta), sigma_(W_z)) = (63.5, 49.6, 51.3) km/s. Finally, we suggest that UCAC2 proper motion errors may be overestimated by about 25%Comment: Submitted to ApJ. 11 pages including 6 figure

Molecular Pathways Underlying Adaptive Repair of the Injured Kidney: Novel Donation After Cardiac Death and Acute Kidney Injury Platforms

International audienceObjective: To test the hypothesis that gene expression profiling in peripheral blood from patients who have undergone kidney transplantation (KT) will provide mechanistic insights regarding graft repair and regeneration.Background: Renal grafts obtained from living donors (LD) typically function immediately, whereas organs from donation after cardiac death (DCD) or acute kidney injury (AKI) donors may experience delayed function with eventual recovery. Thus, recipients of LD, DCD, and AKI kidneys were studied to provide a more complete understanding of the molecular basis for renal recovery.Methods: Peripheral blood was collected from LD and DCD/AKI recipients before transplant and throughout the first 30 days thereafter. Total RNA was isolated and assayed on whole genome microarrays.Results: Comparison of longitudinal gene expression between LD and AKI/DCD revealed 2 clusters, representing 141 differentially expressed transcripts. A subset of 11 transcripts was found to be differentially expressed in AKI/DCD versus LD. In all recipients, the most robust gene expression changes were observed in the first day after transplantation. After day 1, gene expression profiles differed depending upon the source of the graft. In patients receiving LD grafts, the expression of most genes did not remain markedly elevated beyond the first day post-KT. In the AKI/DCD groups, elevations in gene expression were maintained for at least 5 days post-KT. In all recipients, the pattern of coordinate gene overexpression subsided by 28 to 30 days.Conclusions: Gene expression in peripheral blood of AKI/DCD recipients offers a novel platform to understand the potential mechanisms and timing of kidney repair and regeneration after transplantation

Multicenter Trial of a Combination Probiotic for Children with Gastroenteritis.

Background Gastroenteritis accounts for approximately 1.7 million visits to the emergency department (ED) by children in the United States every year. Data to determine whether the use of probiotics improves outcomes in these children are lacking. Methods We conducted a randomized, double-blind trial involving 886 children 3 to 48 months of age with gastroenteritis who presented to six pediatric EDs in Canada. Participants received a 5-day course of a combination probiotic product containing Lactobacillus rhamnosus R0011 and L. helveticus R0052, at a dose of 4.0×10 Results Moderate-to-severe gastroenteritis within 14 days after enrollment occurred in 108 of 414 participants (26.1%) who were assigned to probiotics and 102 of 413 participants (24.7%) who were assigned to placebo (odds ratio, 1.06; 95% confidence interval [CI], 0.77 to 1.46; P=0.72). After adjustment for trial site, age, detection of rotavirus in stool, and frequency of diarrhea and vomiting before enrollment, trial-group assignment did not predict moderate-to-severe gastroenteritis (odds ratio, 1.06; 95% CI, 0.76 to 1.49; P=0.74). There were no significant differences between the probiotic group and the placebo group in the median duration of diarrhea (52.5 hours [interquartile range, 18.3 to 95.8] and 55.5 hours [interquartile range, 20.2 to 102.3], respectively; P=0.31) or vomiting (17.7 hours [interquartile range, 0 to 58.6] and 18.7 hours [interquartile range, 0 to 51.6], P=0.18), the percentages of participants with unscheduled visits to a health care provider (30.2% and 26.6%; odds ratio, 1.19; 95% CI, 0.87 to 1.62; P=0.27), and the percentage of participants who reported an adverse event (34.8% and 38.7%; odds ratio, 0.83; 95% CI, 0.62 to 1.11; P=0.21). Conclusions In children who presented to the emergency department with gastroenteritis, twice-daily administration of a combined L. rhamnosus-L. helveticus probiotic did not prevent the development of moderate-to-severe gastroenteritis within 14 days after enrollment. (Funded by the Canadian Institutes of Health Research and others; PROGUT ClinicalTrials.gov number, NCT01853124 .)