9,937 research outputs found
Interleukin 1 Signaling Is Regulated by Leukemia Inhibitory Factor (LIF) and Is Aberrant in Lif−/− Mouse Uterus
This study addresses the regulation of the interleukin 1 (IL1) system in the murine uterine luminal epithelium (LE) and stroma by leukemia inhibitory factor (LIF). Using RT-PCR we compared expression of Il1a, Il1b, Il1rn, Il1r1, and Il1r2 during the pre- and peri-implantation periods of pregnancy in wild-type (WT) and LIF-null LE and stroma. In WT LE, Il1a transcripts were down-regulated on Day 4 of pregnancy (D4), with renewed expression by the evening of D4 (D4 pm). In Lif−/− LE there was a gradual decrease in expression on D2, and expression became undetectable by D6. Il1b and Il1r1 expression were similar in WT and null mice, but Il1rn expression was almost completely lost during the peri-implantation period in Lif−/− LE. In the stroma, Il1a was sharply down-regulated on D4 and reappeared on D4 pm but was only expressed from D3 to D5 in the null mice. Stromal Il1r1 and Il1r2 were also misregulated. Il1rn showed constitutive expression in null stroma in contrast to the loss of expression on D4 in the WT mouse. In Lif-deficient mice, immunostaining indicated a reduction of endometrial IL1A at the time of implantation and of IL1B in stroma. LE-stromal coculture revealed that LIF stimulated the apical secretion of both IL1A and PTGES2 by LE cells without affecting basal secretion of IL1A and with only a small effect on basal PTGES2 secretion. We conclude that Il1a and Il1rn in LE and Il1a, Il1rn, and Il1r1 in stroma are regulated by LIF, which stimulates apical secretion of IL1A by LE
User interaction and uptake challenges to successfully deploying Semantic Web technologies
The Semantic Web community could benefit greatly from 'eating its own dog food' in order to better understand the challenges and opportunities of a Semantic Web from the user perspective. In this paper we describe the deployment of Semantic Web applications and services at the 3rd European Semantic Web Conference (ESWC2006), before presenting results of an evaluation into how these technologies were experienced by delegates. Based on themes identified in the evaluation we highlight seven user interaction and uptake challenges raised by the conference experience, and discuss how these may generalize to the widespread deployment of Semantic Web technologies
Environments and Morphologies of Red Sequence Galaxies with Residual Star Formation in Massive Clusters
We present a photometric investigation into recent star formation in galaxy
clusters at z ~ 0.1. We use spectral energy distribution templates to quantify
recent star formation in large X-ray selected clusters from the LARCS survey
using matched GALEX NUV photometry. These clusters all have signs of red
sequence galaxy recent star formation (as indicated by blue NUV-R colour),
regardless of cluster morphology and size. A trend in environment is found for
these galaxies, such that they prefer to occupy low density, high cluster
radius environments. The morphology of these UV bright galaxies suggests that
they are in fact red spirals, which we confirm with light curves and Galaxy Zoo
voting percentages as morphological proxies. These UV bright galaxies are
therefore seen to be either truncated spiral galaxies, caught by ram pressure
in falling into the cluster, or high mass spirals, with the photometry
dominated by the older stellar population.Comment: Accepted for publication in MNRAS, 11 pages, 11 figure
A New Star-Formation Rate Calibration from Polycyclic Aromatic Hydrocarbon Emission Features and Application to High Redshift Galaxies
We calibrate the integrated luminosity from the polycyclic aromatic
hydrocarbon (PAH) features at 6.2\micron, 7.7\micron\ and 11.3\micron\ in
galaxies as a measure of the star-formation rate (SFR). These features are
strong (containing as much as 5-10\% of the total infrared luminosity) and
suffer minimal extinction. Our calibration uses \spitzer\ Infrared Spectrograph
(IRS) measurements of 105 galaxies at , infrared (IR) luminosities
of 10^9 - 10^{12} \lsol, combined with other well-calibrated SFR indicators.
The PAH luminosity correlates linearly with the SFR as measured by the
extinction-corrected \ha\ luminosity over the range of luminosities in our
calibration sample. The scatter is 0.14 dex comparable to that between SFRs
derived from the \paa\ and extinction-corrected \ha\ emission lines, implying
the PAH features may be as accurate a SFR indicator as hydrogen recombination
lines. The PAH SFR relation depends on gas-phase metallicity, for which we
supply an empirical correction for galaxies with 0.2 < \mathrm{Z} \lsim
0.7~\zsol. We present a case study in advance of the \textit{James Webb Space
Telescope} (\jwst), which will be capable of measuring SFRs from PAHs in
distant galaxies at the peak of the SFR density in the universe () with
SFRs as low as ~10~\sfrunits. We use \spitzer/IRS observations of the PAH
features and \paa\ emission plus \ha\ measurements in lensed star-forming
galaxies at to demonstrate the ability of the PAHs to derive
accurate SFRs. We also demonstrate that because the PAH features dominate the
mid-IR fluxes, broad-band mid-IR photometric measurements from \jwst\ will
trace both the SFR and provide a way to exclude galaxies dominated by an AGN.Comment: Accepted for publication in Ap
Patterns in participation: Factors influencing parent attendance at two, centre-based early childhood interventions
Interventions training parents of at-risk children have received considerable empirical support but their effectiveness is undermined by low attendance rates. This research sought to clarify why parents, even with the best of intentions, fail to follow through to full participation in workshop programs; and to provide insight into ways to improve parental engagement. We examined participation in Parents as Partners, a school-based, early childhood intervention. Demographic and ongoing educational, social, emotional and behavioural data for 136 parent-child dyads were gathered from parents, teachers and children. Mitigation of a wide range of factors previously identified as barriers to attendance was also attempted. A post-intervention survey was conducted to examine parents’ insights into their attendance patterns. Overall, 91 parents attended and 44 failed to attend any workshops. Higher parent education and SEI, and better child language skills were good predictors of attendance (87%), but poor predictors of nonattendance (42%). Additionally, parent-child dyad profiles suggested that children of nonattending parents were more likely to benefit from workshop content than attenders’ children. Survey data suggested that attenders organised their schedules to facilitate follow-through but nonattenders were unable to do so. Family characteristics and practical reasons were central, interacting factors affecting attendance. Parental self-organisation appeared to moderate follow-through and to stem from lifestyle constraints related to lower SEI and parent education. This produced high nonattendance rates in parents of children who most needed support. It is urgent to discover to what extent innovative delivery platforms currently being explored (e.g., internet/social media) can improve parental engagement
Fast nonlinear ion transport via field-induced hydrodynamic slip in sub-20-nm hydrophilic nanofluidic transistors
Electrolyte transport through an array of 20 nm wide, 20 μm long SiO_2 nanofluidic transistors is described. At sufficiently low ionic strength, the Debye screening length exceeds the channel width, and ion transport is limited by the negatively charged channel surfaces. At source−drain biases >5 V, the current exhibits a sharp, nonlinear increase, with a 20−50-fold conductance enhancement. This behavior is attributed to a breakdown of the zero-slip condition. Implications for energy conversion devices are discussed
Small heat-shock proteins: important players in regulating cellular proteostasis
Small heat-shock proteins (sHsps) are a diverse family of intra-cellular molecular chaperone proteins that play a critical role in mitigating and preventing protein aggregation under stress conditions such as elevated temperature, oxidation and infection. In doing so, they assist in the maintenance of protein homeostasis (proteostasis) thereby avoiding the deleterious effects that result from loss of protein function and/or protein aggregation. The chaperone properties of sHsps are therefore employed extensively in many tissues to prevent the development of diseases associated with protein aggregation. Significant progress has been made of late in understanding the structure and chaperone mechanism of sHsps. In this review, we discuss some of these advances, with a focus on mammalian sHsp hetero-oligomerisation, the mechanism by which sHsps act as molecular chaperones to prevent both amorphous and fibrillar protein aggregation, and the role of post-translational modifications in sHsp chaperone function, particularly in the context of disease.SM was supported by a Royal Society Dorothy Hodgkin Fellowship, HE is supported by an Australian Research Council Future Fellowship (FT110100586) and JC is supported by a National Health and Medical Research Council Project Grant (#1068087)
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