80 research outputs found
High efficiency CCD detectors at UV wavelengths
The Faint Intergalactic Redshifted Emission Balloon (FIREBall) is a NASA/CNES balloon-borne ultraviolet
multi-object spectrograph designed to observe the diffuse gas around galaxies (the circumgalactic medium) via
line emission redshifted to ~ 205 nm. FIREBall uses a ultraviolet-optimized delta doped e2v CCD201 with a
custom designed high efficiency five layer anti-re
ection coating. This combination achieves very high quantum
efficiency (QE) and photon-counting capability, a first for a CCD detector in this wavelength range. We also present new work on red blocking mirror coatings to reduce red leak
The GALFA-HI Compact Cloud Catalog
We present a catalog of 1964 isolated, compact neutral hydrogen clouds from
the Galactic Arecibo L-Band Feed Array Survey Data Release One (GALFA-HI DR1).
The clouds were identified by a custom machine-vision algorithm utilizing
Difference of Gaussian kernels to search for clouds smaller than 20'. The
clouds have velocities typically between |VLSR| = 20-400 km/s, linewidths of
2.5-35 km/s, and column densities ranging from 1 - 35 x 10^18 cm^-2. The
distances to the clouds in this catalog may cover several orders of magnitude,
so the masses may range from less than a Solar mass for clouds within the
Galactic disc, to greater than 10^4 Solar Masses for HVCs at the tip of the
Magellanic Stream. To search for trends, we separate the catalog into five
populations based on position, velocity, and linewidth: high velocity clouds
(HVCs); galaxy candidates; cold low velocity clouds (LVCs); warm, low
positive-velocity clouds in the third Galactic Quadrant; and the remaining warm
LVCs. The observed HVCs are found to be associated with previously-identified
HVC complexes. We do not observe a large population of isolated clouds at high
velocities as some models predict. We see evidence for distinct histories at
low velocities in detecting populations of clouds corotating with the Galactic
disc and a set of clouds that is not corotating.Comment: 34 Pages, 9 Figures, published in ApJ (2012, ApJ, 758, 44), this
version has the corrected fluxes and corresponding flux histogram and masse
A Maternal High-Fat, High-Sucrose Diet Has Sex-Specific Effects on Fetal Glucocorticoids with Little Consequence for Offspring Metabolism and Voluntary Locomotor Activity in Mice
Maternal overnutrition and obesity during pregnancy can have long-term effects on offspring physiology and behaviour. These developmental programming effects may be mediated by fetal exposure to glucocorticoids, which is regulated in part by placental 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and 2. We tested whether a maternal high-fat, high-sucrose diet would alter expression of placental 11β-HSD1 and 2, thereby increasing fetal exposure to maternal glucocorticoids, with downstream effects on offspring physiology and behaviour. C57BL/6J mice were fed a high-fat, high-sucrose (HFHS) diet or a nutrient-matched low-fat, no-sucrose control diet prior to and during pregnancy and lactation. At day 17 of gestation, HFHS dams had ~20% lower circulating corticosterone levels than controls. Furthermore, there was a significant interaction between maternal diet and fetal sex for circulating corticosterone levels in the fetuses, whereby HFHS males tended to have higher corticosterone than control males, with no effect in female fetuses. However, placental 11β-HSD1 or 11β-HSD2 expression did not differ between diets or show an interaction between diet and sex. To assess potential long-term consequences of this sex-specific effect on fetal corticosterone, we studied locomotor activity and metabolic traits in adult offspring. Despite a sex-specific effect of maternal diet on fetal glucocorticoids, there was little evidence of sex-specific effects on offspring physiology or behaviour, although HFHS offspring of both sexes had higher circulating corticosterone at 9 weeks of age. Our results suggest the existence of as yet unknown mechanisms that mitigate the effects of altered glucocorticoid exposure early in development, making offspring resilient to the potentially negative effects of a HFHS maternal diet
Searches After Gravitational-waves Using ARizona Observatories (SAGUARO): System Overview and First Results from Advanced LIGO/Virgo's Third Observing Run
We present Searches After Gravitational-waves Using ARizona Observatories
(SAGUARO), a comprehensive effort dedicated to the discovery and
characterization of optical counterparts to gravitational wave (GW) events.
SAGUARO utilizes ground-based facilities ranging from 1.5m to 10m in diameter,
located primarily in the Northern Hemisphere. We provide an overview of
SAGUARO's telescopic resources, pipeline for transient detection, and database
for candidate visualization. We describe SAGUARO's discovery component, which
utilizes the ~deg field-of-view optical imager on the Mt. Lemmon 1.5m
telescope, reaching limits of ~AB mag while rapidly tiling large
areas. We also describe the follow-up component of SAGUARO, used for rapid
vetting and monitoring of optical candidates. With the onset of Advanced
LIGO/Virgo's third observing run, we present results from the first three
SAGUARO searches following the GW events S190408an, S190425z and S190426c,
which serve as a valuable proof-of-concept of SAGUARO. We triggered and
searched 15, 60 and 60 deg respectively, 17.6, 1.4 and 41.8 hrs after the
initial GW alerts. We covered 7.8, 3.0 and 5.1\% of the total probability
within the GW event localizations, reaching 3 limits of 19.8, 21.3 and
20.8 AB mag, respectively. Although no viable counterparts associated with
these events were found, we recovered 6 known transients and ruled out 5
potential candidates. We also present Large Binocular Telescope spectroscopy of
PS19eq/SN2019ebq, a promising kilonova candidate that was later determined to
be a supernova. With the ability to tile large areas and conduct detailed
follow-up, SAGUARO represents a significant addition to GW counterpart
searches.Comment: 16 pages, 7 figures, 1 table. Accepted to ApJ
Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid
BACKGROUND: Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption
Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic
BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.
METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation.
FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p\u3c0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p\u3c0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile.
INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
The association among cytochrome P450 3A, progesterone receptor polymorphisms, plasma 17-alpha hydroxyprogesterone caproate concentrations, and spontaneous preterm birth
Background Infants born <37 weeks’ gestation are of public health concern since complications associated with preterm birth are the leading cause of mortality in children <5 years of age and a major cause of morbidity and lifelong disability. The administration of 17-alpha hydroxyprogesterone caproate reduces preterm birth by 33% in women with history of spontaneous preterm birth. We demonstrated previously that plasma concentrations of 17-alpha hydroxyprogesterone caproate vary widely among pregnant women and that women with 17-alpha hydroxyprogesterone caproate plasma concentrations in the lowest quartile had spontaneous preterm birth rates of 40% vs rates of 25% in those women with higher concentrations. Thus, plasma concentrations are an important factor in determining drug efficacy but the reason 17-alpha hydroxyprogesterone caproate plasma concentrations vary so much is unclear. Predominantly, 17-alpha hydroxyprogesterone caproate is metabolized by CYP3A4 and CYP3A5 enzymes. Objective We sought to: (1) determine the relation between 17-alpha hydroxyprogesterone caproate plasma concentrations and single nucleotide polymorphisms in CYP3A4 and CYP3A5; (2) test the association between progesterone receptor single nucleotide polymorphisms and spontaneous preterm birth; and (3) test whether the association between plasma concentrations of 17-alpha hydroxyprogesterone caproate and spontaneous preterm birth varied by progesterone receptor single nucleotide polymorphisms. Study Design In this secondary analysis, we evaluated genetic polymorphism in 268 pregnant women treated with 17-alpha hydroxyprogesterone caproate, who participated in a placebo-controlled trial to evaluate the benefit of omega-3 supplementation in women with history of spontaneous preterm birth. Trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were measured between 25-28 weeks of gestation after a minimum of 5 injections of 17-alpha hydroxyprogesterone caproate. We extracted DNA from maternal blood samples and genotyped the samples using TaqMan (Applied Biosystems, Foster City, CA) single nucleotide polymorphism genotyping assays for the following single nucleotide polymorphisms: CYP3A4*1B, CYP3A4*1G, CYP3A4*22, and CYP3A5*3; and rs578029, rs471767, rs666553, rs503362, and rs500760 for progesterone receptor. We adjusted for prepregnancy body mass index, race, and treatment group in a multivariable analysis. Differences in the plasma concentrations of 17-alpha hydroxyprogesterone caproate by genotype were evaluated for each CYP single nucleotide polymorphism using general linear models. The association between progesterone receptor single nucleotide polymorphisms and frequency of spontaneous preterm birth was tested using logistic regression. A logistic model also tested interaction between 17-alpha hydroxyprogesterone caproate concentrations with each progesterone receptor single nucleotide polymorphism for the outcome of spontaneous preterm birth. Results The association between CYP single nucleotide polymorphisms *22, *1G, *1B, and *3 and trough plasma concentrations of 17-alpha hydroxyprogesterone caproate was not statistically significant (P =.68,.44,.08, and.44, respectively). In an adjusted logistic regression model, progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 were not associated with the frequency of spontaneous preterm birth (P =.29,.10,.76,.09, and.43, respectively). Low trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were statistically associated with a higher frequency of spontaneous preterm birth (odds ratio, 0.78; 95% confidence ratio, 0.61–0.99; P =.04 for trend across quartiles), however no significant interaction with the progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 was observed (P =.13,.08,.10,.08, and.13, respectively). Conclusion The frequency of recurrent spontaneous preterm birth appears to be associated with trough 17-alpha hydroxyprogesterone caproate plasma concentrations. However, the wide variation in trough 17-alpha hydroxyprogesterone caproate plasma concentrations is not attributable to polymorphisms in CYP3A4 and CYP3A5 genes. Progesterone receptor polymorphisms do not predict efficacy of 17-alpha hydroxyprogesterone caproate. The limitations of this secondary analysis include that we had a relative small sample size (n = 268) and race was self-reported by the patients
- …