88 research outputs found
Uterine Endoplasmic Reticulum Stress and Its Unfolded Protein Response May Regulate Caspase 3 Activation in the Pregnant Mouse Uterus
We have previously proposed that uterine caspase-3 may modulate uterine contractility in a gestationally regulated fashion. The objective of this study was to determine the mechanism by which uterine caspase-3 is activated and consequently controlled in the pregnant uterus across gestation. Utilizing the mouse uterus as our gestational model we examined the intrinsic and extrinsic apoptotic signaling pathways and the endoplasmic reticulum stress response as potential activators of uterine caspase-3 at the transcriptional and translational level. Our study revealed robust activation of the uterine myocyte endoplasmic reticulum stress response and its adaptive unfolded protein response during pregnancy coinciding respectively with increased uterine caspase-3 activity and its withdrawal to term. In contrast the intrinsic and extrinsic apoptotic signaling pathways remained inactive across gestation. We speculate that physiological stimuli experienced by the pregnant uterus likely potentiates the uterine myocyte endoplasmic reticulum stress response resulting in elevated caspase-3 activation, which is isolated to the pregnant mouse myometrium. However as term approaches, activation of an elevated adaptive unfolded protein response acts to limit the endoplasmic reticulum stress response inhibiting caspase-3 resulting in its decline towards term. We speculate that these events have the capacity to regulate gestational length in a caspase-3 dependent manne
RORα and 25-Hydroxycholesterol Crosstalk Regulates Lipid Droplet Homeostasis in Macrophages.
Nuclear hormone receptors have important roles in the regulation of metabolic and inflammatory pathways. The retinoid-related orphan receptor alpha (Rorα)-deficient staggerer (sg/sg) mice display several phenotypes indicative of aberrant lipid metabolism, including dyslipidemia, and increased susceptibility to atherosclerosis. In this study we demonstrate that macrophages from sg/sg mice have increased ability to accumulate lipids and accordingly exhibit larger lipid droplets (LD). We have previously shown that BMMs from sg/sg mice have significantly decreased expression of cholesterol 25-hydroxylase (Ch25h) mRNA, the enzyme that produces the oxysterol, 25-hydroxycholesterol (25HC), and now confirm this at the protein level. 25HC functions as an inverse agonist for RORα. siRNA knockdown of Ch25h in macrophages up-regulates Vldlr mRNA expression and causes increased accumulation of LDs. Treatment with physiological concentrations of 25HC in sg/sg macrophages restored lipid accumulation back to normal levels. Thus, 25HC and RORα signify a new pathway involved in the regulation of lipid homeostasis in macrophages, potentially via increased uptake of lipid which is suggested by mRNA expression changes in Vldlr and other related genes
AMI-LA radio continuum observations of Spitzer c2d small clouds and cores: Perseus region
We present deep radio continuum observations of the cores identified as
deeply embedded young stellar objects in the Perseus molecular cloud by the
Spitzer c2d programme at a wavelength of 1.8 cm with the Arcminute Microkelvin
Imager Large Array (AMI-LA). We detect 72% of Class 0 objects from this sample
and 31% of Class I objects. No starless cores are detected. We use the flux
densities measured from these data to improve constraints on the correlations
between radio luminosity and bolometric luminosity, infrared luminosity and,
where measured, outflow force. We discuss the differing behaviour of these
objects as a function of protostellar class and investigate the differences in
radio emission as a function of core mass. Two of four possible very low
luminosity objects (VeLLOs) are detected at 1.8 cm.Comment: 18 pages, 9 figures, accepted MNRA
Physical properties of Herschel selected galaxies in a semi-analytic galaxy formation model
[Abridged] We make use of a semi-analytic cosmological model that includes
simple prescriptions for dust attenuation and emission to make predictions for
the observable and physical properties of galaxies that may be detected by the
recently launched Herschel Space Observatory in deep fields such as
GOODS-Herschel. We compare our predictions for differential galaxy number
counts in the PACS (100 & 160) and SPIRE (250, 350, and 500 micron) bands with
available observations. We find very good agreement with the counts in the PACS
bands, for the overall counts and for galaxies binned by redshift at z< 2. At z
> 2 our model underpredicts the number of bright galaxies by a factor of ten.
The agreement is much worse for all three SPIRE bands, and becomes
progressively worse with increasing wavelength. We discuss a number of possible
reasons for these discrepancies, and hypothesize that the effect of blending on
the observational flux estimates is likely to be the dominant issue. We note
that the PACS number counts are relatively robust to changes in the dust
emission templates, while the predicted SPIRE number counts are more template
dependent. We present quantitative predictions for the relationship between the
observed PACS 160 and SPIRE 250 micron fluxes and physical quantities such as
halo mass, stellar mass, cold gas mass, star formation rate, and total infrared
(IR) luminosity, at different redshifts. We also present quantitative
predictions for the correlation between PACS 160 micron flux and the
probability that a galaxy has experienced a recent major or minor merger.
Although our models predict a strong correlation between these quantities, such
that more IR-luminous galaxies are more likely to be merger-driven, we find
that more than half of all high redshift IR-luminous galaxies detected by
Herschel are able to attain their high star formation rates without enhancement
by a merger.Comment: Accepted for publication in MNRA
AMI-LA radio continuum observations of Spitzer c2d small clouds and cores: Serpens region
We present deep radio continuum observations of the cores identified as
deeply embedded young stellar objects in the Serpens molecular cloud by the
Spitzer c2d programme at a wavelength of 1.8cm with the Arcminute Microkelvin
Imager Large Array (AMI-LA). These observations have a resolution of ~30arcsec
and an average sensitivity of 19microJy/beam. The targets are predominantly
Class I sources, and we find the detection rate for Class I objects in this
sample to be low (18%) compared to that of Class 0 objects (67%), consistent
with previous works. For detected objects we examine correlations of radio
luminosity with bolometric luminosity and envelope mass and find that these
data support correlations found by previous samples, but do not show any
indiction of the evolutionary divide hinted at by similar data from the Perseus
molecular cloud when comparing radio luminosity with envelope mass. We conclude
that envelope mass provides a better indicator for radio luminosity than
bolometric luminosity, based on the distribution of deviations from the two
correlations. Combining these new data with archival 3.6cm flux densities we
also examine the spectral indices of these objects and find an average spectral
index of 0.53+/-1.14, consistent with the canonical value for a partially
optically thick spherical or collimated stellar wind. However, we caution that
possible inter-epoch variability limits the usefulness of this value, and such
variability is supported by our identification of a possible flare in the radio
history of Serpens SMM 1.Comment: accepted MNRA
Why Has Personality Psychology Played an Outsized Role in the Credibility Revolution?
21 pages. Published at PsychOpen: 10.5964/ps.6001Personality is not the most popular subfield of psychology. But, in one way or another, personality psychologists have played an outsized role in the ongoing “credibility revolution” in psychology. Not only have individual personality psychologists taken on visible roles in the movement, but our field’s practices and norms have now become models for other fields to emulate (or, for those who share Baumeister’s (2016, https://doi.org/10.1016/j.jesp.2016.02.003) skeptical view of the consequences of increasing rigor, a model for what to avoid). In this article we discuss some unique features of our field that may have placed us in an ideal position to be leaders in this movement. We do so from a subjective perspective, describing our impressions and opinions about possible explanations for personality psychology’s disproportionate role in the credibility revolution. We also discuss some ways in which personality psychology remains less-than-optimal, and how we can address these flaws
Models of classroom assessment for course-based research experiences
Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment—(1) Assessing Laboratory Work and Scientific Thinking; (2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; (3) Appraising Forms of Scientific Communication; and (4) Metacognition of Learning—along with a set of practices for each aim. These aims and practices of assessment were then integrated with previously developed models of course-based research instruction to reveal an assessment program in which instructors provide extensive feedback to support productive student engagement in research while grading those aspects of research that are necessary for the student to succeed. Assessment conducted in this way delicately balances the need to facilitate students’ ongoing research with the requirement of a final grade without undercutting the important aims of a CRE education
Elevated Levels of Uterine Anti-Apoptotic Signaling May Activate NFKB and Potentially Confer Resistance to Caspase 3-Mediated Apoptotic Cell Death During Pregnancy in Mice1
Comparison of Primary Cultured Human Uterine Smooth Muscle Cells with a Telomerase Immortalized Human Myometrial Cell Line (hTERT-HM).
Analysis of the Effects of PFAS and Metallic Co-pollutants on Bacterial Respiration
Per- and polyfluoroalkyl substances are stable, man-made compounds that persist in the environment. We investigated perfluorooctanoic acid’s impact on bacterial respiration in activated sludge and potential co-toxicity with zinc and hexavalent chromium. During experimentation, the concentrations of heavy metals were varied on a gradient with a fixed concentration of PFOA to analyze patterns of growth or inhibition. We analyzed the mass of oxygen consumed over time to draw conclusions about the effects of PFOA, co-toxicity, and age of activated sludge. Our data generally supported the hypothesis of a negative correlation between pollutant levels and bacterial consumption of oxygen
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