Search

The Variables and Slow Transients Survey (VAST) on the Australian Square Kilometre Array Pathfinder (ASKAP) is designed to detect highly variable and transient radio sources on timescales from 5 s to$\sim\!5$yr. In this paper, we present the survey description, observation strategy and initial results from the VAST Phase I Pilot Survey. This pilot survey consists of$\sim\!162$h of observations conducted at a central frequency of 888 MHz between 2019 August and 2020 August, with a typical rms sensitivity of$0.24\ \mathrm{mJy\ beam}^{-1}$and angular resolution of$12-20$arcseconds. There are 113 fields, each of which was observed for 12 min integration time, with between 5 and 13 repeats, with cadences between 1 day and 8 months. The total area of the pilot survey footprint is 5 131 square degrees, covering six distinct regions of the sky. An initial search of two of these regions, totalling 1 646 square degrees, revealed 28 highly variable and/or transient sources. Seven of these are known pulsars, including the millisecond pulsar J2039–5617. Another seven are stars, four of which have no previously reported radio detection (SCR J0533–4257, LEHPM 2-783, UCAC3 89–412162 and 2MASS J22414436–6119311). Of the remaining 14 sources, two are active galactic nuclei, six are associated with galaxies and the other six have no multi-wavelength counterparts and are yet to be identified.

We search NANOGrav's 12.5-year data set for evidence of a gravitational wave background (GWB) with all the spatial correlations allowed by general metric theories of gravity. We find no substantial evidence in favor of the existence of such correlations in our data. We find that scalar-transverse (ST) correlations yield signal-to-noise ratios and Bayes factors that are higher than quadrupolar (tensor transverse, TT) correlations. Specifically, we find ST correlations with a signal-to-noise ratio of 2.8 that are preferred over TT correlations (Hellings and Downs correlations) with Bayesian odds of about 20:1. However, the significance of ST correlations is reduced dramatically when we include modeling of the Solar System ephemeris systematics and/or remove pulsar J0030$+$0451 entirely from consideration. Even taking the nominal signal-to-noise ratios at face value, analyses of simulated data sets show that such values are not extremely unlikely to be observed in cases where only the usual TT modes are present in the GWB. In the absence of a detection of any polarization mode of gravity, we place upper limits on their amplitudes for a spectral index of $\gamma = 5$ and a reference frequency of $f_\text{yr} = 1 \text{yr}^{-1}$. Among the upper limits for eight general families of metric theories of gravity, we find the values of $A^{95\%}_{TT} = (9.7 \pm 0.4)\times 10^{-16}$ and $A^{95\%}_{ST} = (1.4 \pm 0.03)\times 10^{-15}$ for the family of metric spacetime theories that contain both TT and ST modes., Comment: 24 pages, 18 figures, 3 appendices. Please send any comments/questions to Nima Laal (laaln@oregonstate.edu)

The NANOGrav Collaboration reported strong Bayesian evidence for a common-spectrum stochastic process in its 12.5-yr pulsar timing array dataset, with median characteristic strain amplitude at periods of a year of $A_{\rm yr} = 1.92^{+0.75}_{-0.55} \times 10^{-15}$. However, evidence for the quadrupolar Hellings \& Downs interpulsar correlations, which are characteristic of gravitational wave signals, was not yet significant. We emulate and extend the NANOGrav dataset, injecting a wide range of stochastic gravitational wave background (GWB) signals that encompass a variety of amplitudes and spectral shapes, and quantify three key milestones: (I) Given the amplitude measured in the 12.5 yr analysis and assuming this signal is a GWB, we expect to accumulate robust evidence of an interpulsar-correlated GWB signal with 15--17 yrs of data, i.e., an additional 2--5 yrs from the 12.5 yr dataset; (II) At the initial detection, we expect a fractional uncertainty of $40\%$ on the power-law strain spectrum slope, which is sufficient to distinguish a GWB of supermassive black-hole binary origin from some models predicting more exotic origins;(III) Similarly, the measured GWB amplitude will have an uncertainty of $44\%$ upon initial detection, allowing us to arbitrate between some population models of supermassive black-hole binaries. In addition, power-law models are distinguishable from those having low-frequency spectral turnovers once 20~yrs of data are reached. Even though our study is based on the NANOGrav data, we also derive relations that allow for a generalization to other pulsar-timing array datasets. Most notably, by combining the data of individual arrays into the International Pulsar Timing Array, all of these milestones can be reached significantly earlier., 15 pages, 7 figures

When galaxies merge, the supermassive black holes in their centers may form binaries and emit low-frequency gravitational radiation in the process. In this paper, we consider the galaxy 3C 66B, which was used as the target of the first multimessenger search for gravitational waves. Due to the observed periodicities present in the photometric and astrometric data of the source, it has been theorized to contain a supermassive black hole binary. Its apparent 1.05-year orbital period would place the gravitational-wave emission directly in the pulsar timing band. Since the first pulsar timing array study of 3C 66B, revised models of the source have been published, and timing array sensitivities and techniques have improved dramatically. With these advances, we further constrain the chirp mass of the potential supermassive black hole binary in 3C 66B to less than (1.65 ± 0.02) × 109 M ⊙ using data from the NANOGrav 11-year data set. This upper limit provides a factor of 1.6 improvement over previous limits and a factor of 4.3 over the first search done. Nevertheless, the most recent orbital model for the source is still consistent with our limit from pulsar timing array data. In addition, we are able to quantify the improvement made by the inclusion of source properties gleaned from electromagnetic data over “blind” pulsar timing array searches. With these methods, it is apparent that it is not necessary to obtain exact a priori knowledge of the period of a binary to gain meaningful astrophysical inferences.

The mergers of supermassive black hole binaries (SMBHBs) promise to be incredible sources of gravitational waves (GWs). While the oscillatory part of the merger gravitational waveform will be outside the frequency sensitivity range of pulsar timing arrays (PTAs), the non-oscillatory GW memory effect is detectable. Further, any burst of gravitational waves will produce GW memory, making memory a useful probe of unmodeled exotic sources and new physics. We searched the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 11-year data set for GW memory. This dataset is sensitive to very low frequency GWs of $\sim3$ to $400$ nHz (periods of $\sim11$ yr $-$ $1$ mon). Finding no evidence for GWs, we placed limits on the strain amplitude of GW memory events during the observation period. We then used the strain upper limits to place limits on the rate of GW memory causing events. At a strain of $2.5\times10^{-14}$, corresponding to the median upper limit as a function of source sky position, we set a limit on the rate of GW memory events at $, Comment: 10 pages, 6 figures, submitted to ApJ

We extract interstellar scintillation parameters for pulsars observed by the NANOGrav radio pulsar timing program. Dynamic spectra for the observing epochs of each pulsar were used to obtain estimates of scintillation timescales, scintillation bandwidths, and the corresponding scattering delays using a stretching algorithm to account for frequency-dependent scaling. We were able to measure scintillation bandwidths for 28 pulsars at 1500 MHz and 15 pulsars at 820 MHz. We examine scaling behavior for 17 pulsars and find power-law indices ranging from $-0.7$ to $-3.6$, though these may be biased shallow due to insufficient frequency resolution at lower frequencies. We were also able to measure scintillation timescales for six pulsars at 1500 MHz and seven pulsars at 820 MHz. There is fair agreement between our scattering delay measurements and electron-density model predictions for most pulsars. We derive interstellar scattering-based transverse velocities assuming isotropic scattering and a scattering screen halfway between the pulsar and earth. We also estimate the location of the scattering screens assuming proper motion and interstellar scattering-derived transverse velocities are equal. We find no correlations between variations in scattering delay and either variations in dispersion measure or flux density. For most pulsars for which scattering delays were measurable, we find that time of arrival uncertainties for a given epoch are larger than our scattering delay measurements, indicating that variable scattering delays are currently subdominant in our overall noise budget but are important for achieving precisions of tens of ns or less., Comment: Accepted to ApJ

We present a new analysis of the profile data from the 47 millisecond pulsars comprising the 12.5-year data set of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), which is presented in a parallel paper (Alam et al. 2021a; NG12.5). Our reprocessing is performed using "wideband" timing methods, which use frequency-dependent template profiles, simultaneous time-of-arrival (TOA) and dispersion measure (DM) measurements from broadband observations, and novel analysis techniques. In particular, the wideband DM measurements are used to constrain the DM portion of the timing model. We compare the ensemble timing results to NG12.5 by examining the timing residuals, timing models, and noise model components. There is a remarkable level of agreement across all metrics considered. Our best-timed pulsars produce encouragingly similar results to those from NG12.5. In certain cases, such as high-DM pulsars with profile broadening, or sources that are weak and scintillating, wideband timing techniques prove to be beneficial, leading to more precise timing model parameters by 10-15%. The high-precision, multi-band measurements of several pulsars indicate frequency-dependent DMs. Compared to the narrowband analysis in NG12.5, the TOA volume is reduced by a factor of 33, which may ultimately facilitate computational speed-ups for complex pulsar timing array analyses. This first wideband pulsar timing data set is a stepping stone, and its consistent results with NG12.5 assure us that such data sets are appropriate for gravitational wave analyses., Comment: 62 pages, 55 figures, 5 tables, 3 appendices. Data available at http://nanograv.org/data/ and via DOI 10.5281/zenodo.4312887

We present time-of-arrival (TOA) measurements and timing models of 47 millisecond pulsars (MSPs) observed from 2004 to 2017 at the Arecibo Observatory and the Green Bank Telescope by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). The observing cadence was three to four weeks for most pulsars over most of this time span, with weekly observations of six sources. These data were collected for use in low-frequency gravitational wave searches and for other astrophysical purposes. We detail our observational methods and present a set of TOA measurements, based on "narrowband" analysis, in which many TOAs are calculated within narrow radio-frequency bands for data collected simultaneously across a wide bandwidth. A separate set of "wideband" TOAs will be presented in a companion paper. We detail a number of methodological changes compared to our previous work which yield a cleaner and more uniformly processed data set. Our timing models include several new astrometric and binary pulsar measurements, including previously unpublished values for the parallaxes of PSRs J1832-0836 and J2322+2057, the secular derivatives of the projected semi-major orbital axes of PSRs J0613-0200 and J2229+2643, and the first detection of the Shapiro delay in PSR J2145-0750. We report detectable levels of red noise in the time series for 14 pulsars. As a check on timing model reliability, we investigate the stability of astrometric parameters across data sets of different lengths. We report flux density measurements for all pulsars observed. Searches for stochastic and continuous gravitational waves using these data will be subjects of forthcoming publications., Comment: 54 pages, 52 figures, 7 tables, 1 appendix. Data are available at http://nanograv.org/data/ and via the DOI 10.5281/zenodo.4312297

We search for extrasolar planets around millisecond pulsars using pulsar timing data and seek to determine the minimum detectable planetary masses as a function of orbital period. Using the 11-year data set from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), we look for variations from our models of pulse arrival times due to the presence of exoplanets. No planets are detected around the millisecond pulsars in the NANOGrav 11-year data set, but taking into consideration the noise levels of each pulsar and the sampling rate of our observations, we develop limits that show we are sensitive to planetary masses as low as that of the moon. We analyzed potential planet periods, P, in the range 7 days < P < 2000 days, with somewhat smaller ranges for some binary pulsars. The planetary mass limit for our median-sensitivity pulsar within this period range is 1 M_moon (P / 100 days)^(-2/3)., Revised and accepted by ApJ Letters

SCOPE The polyphenol xanthohumol (XN) improves dysfunctional glucose and lipid metabolism in diet-induced obesity animal models. Because XN changes intestinal microbiota composition, the study hypothesizes that XN requires the microbiota to mediate its benefits. METHODS AND RESULTS To test the hypothesis, the study feeds conventional and germ-free male Swiss Webster mice either a low-fat diet (LFD, 10% fat derived calories), a high-fat diet (HFD, 60% fat derived calories), or a high-fat diet supplemented with XN at 60 mg kg-1 body weight per day (HXN) for 10 weeks, and measure parameters of glucose and lipid metabolism. In conventional mice, the study discovers XN supplementation decreases plasma insulin concentrations and improves Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). In germ-free mice, XN supplementation fails to improve these outcomes. Fecal sample 16S rRNA gene sequencing analysis suggests XN supplementation changes microbial composition and dramatically alters the predicted functional capacity of the intestinal microbiota. Furthermore, the intestinal microbiota metabolizes XN into bioactive compounds, including dihydroxanthohumol (DXN), an anti-obesogenic compound with improved bioavailability. CONCLUSION XN requires the intestinal microbiota to mediate its benefits, which involves complex diet-host-microbiota interactions with changes in both microbial composition and functional capacity. The study results warrant future metagenomic studies which will provide insight into complex microbe-microbe interactions and diet-host-microbiota interactions.

The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project has the primary goal of detecting and characterizing low-frequency gravitational waves through high-precision pulsar timing. The mitigation of interstellar effects is crucial to achieve the necessary precision for gravitational wave detection. Effects like dispersion and scattering are more influential at lower observing frequencies, with the variation of these quantities over week-month timescales requiring high-cadence multi-frequency observations for pulsar timing projects. In this work, we utilize the dual-frequency observing capability of the Giant Metrewave Radio Telescope (GMRT) and evaluate the potential decrease in dispersion measure (DM) uncertainties when combined with existing pulsar timing array data. We present the timing analysis for four millisecond pulsars observed with the GMRT simultaneously at 322 and 607 MHz, and compare the DM measurements with those obtained through NANOGrav observations with the Green Bank Telescope (GBT) and Arecibo Observatory at 1400 to 2300 MHz frequencies. Measured DM values with the GMRT and NANOGrav program show significant offsets for some pulsars, which could be caused by pulse profile evolution in the two frequency bands. In comparison to the predicted DM uncertainties when incorporating these low-frequency data into the NANOGrav dataset, we find that higher-precision GMRT data is necessary to provide improved DM measurements. Through the detection and analysis of pulse profile baseline ripple in data on test pulsar B1929+10, we find that, while not important for this data, it may be relevant for other timing datasets. We discuss the possible advantages and challenges of incorporating GMRT data into NANOGrav and International Pulsar Timing Array datasets., 14 pages, 8 figures. Accepted to The Astrophysical Journal

To date, much research has been devoted to understanding how anxiety can affect sport performance, both in practice and in competitive settings. It is well known that sport has the potential for high levels of stress and anxiety, and that practicing and employing a range of psychological strategies can be beneficial in anxiety management. Equally, growing evidence also suggests that anxiety can play a role in sport injury prevention, occurrence, rehabilitation, and the return to sport process. The purpose of this paper is to provide current insights into sport-related anxiety. More specifically, it will provide the reader with definitions and theoretical conceptualizations of sport-related anxiety. This will be followed by making a case for considering the term “performance” to be broader than activities associated with sport-related performance in practice and competition, by including performance activities associated with sport injury prevention, rehabilitation, and the return to sport process. The paper will then highlight the importance of recognizing early signs and symptoms of anxiety, and the potential need for referral. Finally, the conclusions will emphasize the need for appropriate, client-specific, and practitioner competent care for athletes experiencing sport-related anxiety., Video abstract

Despite its importance to our understanding of physics at supranuclear densities, the equation of state (EoS) of matter deep within neutron stars remains poorly understood. Millisecond pulsars (MSPs) are among the most useful astrophysical objects in the Universe for testing fundamental physics, and place some of the most stringent constraints on this high-density EoS. Pulsar timing - the process of accounting for every rotation of a pulsar over long time periods - can precisely measure a wide variety of physical phenomena, including those that allow the measurement of the masses of the components of a pulsar binary system (Lorimer & Kramer 2005). One of these, called relativistic Shapiro delay (Shapiro 1964), can yield precise masses for both an MSP and its companion; however, it is only easily observed in a small subset of high-precision, highly inclined (nearly edge-on) binary pulsar systems. By combining data from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 12.5-year data set with recent orbital-phase-specific observations using the Green Bank Telescope, we have measured the mass of the MSP J0740+6620 to be $\mathbf{2.14^{+0.10}_{-0.09}}$ solar masses (68.3% credibility interval; 95.4% credibility interval is $\mathbf{2.14^{+0.20}_{-0.18}}$ solar masses). It is highly likely to be the most massive neutron star yet observed, and serves as a strong constraint on the neutron star interior EoS., 12 pages, 3 figures, 1 table, published in Nature Astronomy (2019)

The nearby galaxy NGC 3115 contains a known radio-emitting, low-luminosity active galactic nucleus (AGN), and was recently claimed to host a candidate AGN displaced 14.3 pc from the galaxy's optical photocenter. Our goal is to understand whether this represents a single offset AGN, an AGN in orbit around a central black hole, or something else. We present a new, sensitive (RMS = 4.4 $��$Jy beam$^{-1}$) 10 GHz image, which finds evidence for only one AGN. We place a stringent limit on the radio luminosity of any secondary supermassive black hole of $L_{10~\rm{GHz}}, Accepted to ApJ

We search for an isotropic stochastic gravitational-wave background (GWB) in the $12.5$-year pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves. Our analysis finds strong evidence of a stochastic process, modeled as a power-law, with common amplitude and spectral slope across pulsars. The Bayesian posterior of the amplitude for an $f^{-2/3}$ power-law spectrum, expressed as the characteristic GW strain, has median $1.92 \times 10^{-15}$ and $5\%$--$95\%$ quantiles of $1.37$--$2.67 \times 10^{-15}$ at a reference frequency of $f_\mathrm{yr} = 1 ~\mathrm{yr}^{-1}$. The Bayes factor in favor of the common-spectrum process versus independent red-noise processes in each pulsar exceeds $10,000$. However, we find no statistically significant evidence that this process has quadrupolar spatial correlations, which we would consider necessary to claim a GWB detection consistent with general relativity. We find that the process has neither monopolar nor dipolar correlations, which may arise from, for example, reference clock or solar system ephemeris systematics, respectively. The amplitude posterior has significant support above previously reported upper limits; we explain this in terms of the Bayesian priors assumed for intrinsic pulsar red noise. We examine potential implications for the supermassive black hole binary population under the hypothesis that the signal is indeed astrophysical in nature., Comment: 25 pages, 14 figures, 5 tables, 3 appendices. Published in The Astrophysical Journal Letters. Please send any comments/questions to Joseph Simon (joe.simon@nanograv.org). Jupyter notebook tutorials and some MCMC chain files are available at https://github.com/nanograv/12p5yr_stochastic_analysis

Radio emission propagating over an Earth-pulsar line of sight provides a unique probe of the intervening ionized interstellar medium (ISM). Variations in the integrated electron column density along this line of sight, or dispersion measure (DM), have been observed since shortly after the discovery of pulsars. As early as 2006, frequency-dependent dispersion measures have been observed and attributed to several possible causes. Ray-path averaging over different effective light-cone volumes through the turbulent ISM contributes to this effect as will DM misestimation due to radio propagation across compact lensing structures such as those caused by "extreme scattering events". We present methods to assess the variations in frequency-dependent dispersion measures due to the turbulent ISM versus these compact lensing structures along the line of sight. We analyze recent Low-Frequency Array (LOFAR) observations of PSR J2219+4754 to test the underlying physical mechanism of the observed frequency-dependent DM. Previous analyses have indicated the presence of strong lensing due to compact overdensities halfway between the Earth and pulsar. Instead we find the frequency dependence of the DM timeseries for PSR J2219+4754 is consistent with being due solely to ISM turbulence and there is no evidence for any extreme scattering event or small-scale lensing structure. The data show possible deviations from a uniform turbulent medium, suggesting that there may be an enhanced scattering screen near one of the two ends of the line of sight. We present this analysis as an example of the power of low-frequency observations to distinguish the underlying mechanisms in frequency-dependent propagation effects., Comment: 16 pages, 7 figures, accepted by ApJ

The frequency dependence of radio pulse arrival times provides a probe of structures in the intervening media. Demorest et al. 2013 was the first to show a short-term (~100-200 days) reduction in the electron content along the line of sight to PSR J1713+0747 in data from 2008 (approximately MJD 54750) based on an apparent dip in the dispersion measure of the pulsar. We report on a similar event in 2016 (approximately MJD 57510), with average residual pulse-arrival times of approximately 3.0,-1.3, and -0.7 microseconds at 820, 1400, and 2300 MHz, respectively. Timing analyses indicate possible departures from the standard nu^-2 dispersive-delay dependence. We discuss and rule out a wide variety of potential interpretations. We find the likeliest scenario to be lensing of the radio emission by some structure in the interstellar medium, which causes multiple frequency-dependent pulse arrival-time delays., 9 pages, 3 figures, published in ApJ

Gravitational wave (GW) detection with pulsar timing arrays (PTAs) requires accurate noise characterization. The noise of our Galactic-scale GW detector has been systematically evaluated by the Noise Budget and Interstellar Medium Mitigation working groups within the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration. Intrinsically, individual radio millisecond pulsars (MSPs) used by NANOGrav can have some degree of achromatic red spin noise, as well as white noise due to pulse phase jitter. Along any given line-of-sight, the ionized interstellar medium contributes chromatic noise through dispersion measure (DM) variations, interstellar scintillation, and scattering. These effects contain both red and white components. In the future, with wideband receivers, the effects of frequency-dependent DM will become important. Having anticipated and measured these diverse sources of detector noise, the NANOGrav PTA remains well-poised to detect low-frequency GWs., 5 pages, 3 figures, submitted to Journal of Physics: Conference Series as Proceedings of Amaldi 12

We present high-precision timing data over time spans of up to 11 years for 45 millisecond pulsars observed as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project, aimed at detecting and characterizing low-frequency gravitational waves. The pulsars were observed with the Arecibo Observatory and/or the Green Bank Telescope at frequencies ranging from 327 MHz to 2.3 GHz. Most pulsars were observed with approximately monthly cadence, with six high--timing-precision pulsars observed weekly, and all were observed at widely separated frequencies at each observing epoch in order to fit for time-variable dispersion delays. We describe our methods for data processing, time-of-arrival (TOA) calculation, and the implementation of a new, automated method for removing outlier TOAs. We fit a timing model for each pulsar that includes spin, astrometric, and, if necessary, binary parameters, in addition to time-variable dispersion delays and parameters that quantify pulse-profile evolution with frequency. The new timing solutions provide three new parallax measurements, two new Shapiro delay measurements, and two new measurements of large orbital-period variations. We fit models that characterize sources of noise for each pulsar. We find that 11 pulsars show significant red noise, with generally smaller spectral indices than typically measured for non-recycled pulsars, possibly suggesting a different origin. Future papers will use these data to constrain or detect the signatures of gravitational-wave signals., Published in the Astrophysical Journal Supplement Series

The developing fetus requires substantial amounts of fatty acids to support rapid cellular growth and activity. Although the fatty acid composition delivered to the fetus is largely determined by maternal circulating levels, the placenta preferentially transfers physiologically important long-chain polyunsaturated fatty acids (LC-PUFAs), particularly omega-3 (n-3) PUFAs. Maternal dietary supplementation with n-3 PUFAs during pregnancy has been shown to increase gestation length, enhance fetal growth, and reduce the risk of pregnancy complications, although the precise mechanisms governing these effects remain uncertain. Omega-3 PUFAs are involved in several physiological pathways which could account for these effects, including anti-inflammatory, pro-resolving, and anti-oxidative pathways. Recent studies have shown that maternal dietary n-3 PUFA supplementation during rat pregnancy can reduce placental oxidative damage and increase placental levels of pro-resolving mediators, effects associated with enhanced fetal and placental growth. Because several placental disorders, such as intrauterine growth restriction, preeclampsia, and gestational diabetes mellitus, are associated with heightened placental inflammation and oxidative stress, there is considerable interest in the potential for dietary n-3 PUFAs as a therapeutic intervention for these disorders. In this study, we review the impact of dietary n-3 PUFAs on placental function, with particular focus on placental inflammation, inflammatory resolution, and oxidative stress.

To investigate if oral glucose tolerance test (OGTT) associates with changes in maternal symptoms (ie, flushing, sweating), blood nonenzymatic advanced glycation end products (AGE), acute-phase reactive inflammatory markers, and oxidative stress.Prospective case-control study of patients screened for gestational diabetes mellitus (GDM). One hundred nonfasting, second-trimester consecutive pregnant women allocated to either 50 g OGTT or water. Five women who had a 3-hour fasting 100 g OGTT also enrolled. Maternal serum glucose, AGE, soluble receptor for AGE (sRAGE), interleukin (IL)-6, and C-reactive protein (CRP) were immunoassayed. Total radical-trapping antioxidant parameter (TRAP) estimated with antioxidant capacity-peroxyl assay. Data corrected for gestational age and maternal body mass index.During 50 g OGTT there was a decrease in systolic blood pressure not accompanied by the onset of adverse clinical symptoms. There was a decrease in serum glucose levels 1 hour after water ( P = .019) but not glucose ingestion. Serum CRP ( P = .001) but not IL-6 was increased. The AGE, sRAGE, and TRAP levels remained unchanged. Similar results were seen during 100 g OGTT, except serum glucose was significantly elevated after 1 hour.Results suggest screening tools for gestational diabetes are safe and clinically well tolerated during pregnancy. Clinical Trial Registration: ClinicalTrials.gov NCT03029546.

Placental infl ammation is associated with several pregnancy disorders. Infl ammation is limited by anti-infl am- matory and proresolving mechanisms, the latter partly me- diated by resolvins and protectins derived from omega-3 polyunsaturated fatty acids (n-3PUFA). We examined effects of dietary n-3PUFAs on levels of resolvins, protectins, and lipoxygenase (ALOX) enzymes in the rat placenta. Rats con- sumed standard (Std) or high n-3PUFA (Hn3) diets from day 1 of pregnancy; tissues were collected on day 17 or 22 (term = day 23). Maternal Hn3 diet increased resolvin and protectin precursors, 18R/S-HEPE ( P < 0.001), and 17R/ S-HDHA ( P < 0.01) at both days. Resolvins (17R-RvD1 and RvD1) increased at day 22 ( P < 0.001) after Hn3 consump- tion, coincident with higher Alox15b and Alox5 mRNA ex- pression, while RvD2 increased at both days ( P < 0.05). Protectins, PD1, and 10S,17S-DiHDHA increased over late gestation ( P < 0.001), coincident with higher Alox15 mRNA expression ( P < 0.001) and further increased with Hn3 diet ( P < 0.05). Maternal systemic and placental proinfl amma- tory mediators were not suppressed by Hn3 diet; systemic IL1 , placental Il1 , and Il6 mRNA expression increased marginally with Hn3 at day 22 ( P < 0.001), while Ptgs1 ( Cox1 ) expression increased both days ( P < 0.05). Our data indi- cate that maternal n-3PUFA supplementation enhances ex- pression of enzymes in the n-3PUFA metabolic pathway and increases placental levels of resolvins and protectins. — Jones, M. L., P. J. Mark, J. A. Keelan, A. Barden, E. Mas, T. A. Mori, and B. J. Waddell. Maternal dietary omega-3 fatty acid intake increases resolvin and protectin levels in the rat pla- centa. J. Lipid Res. 2013. 54: 2247-2254.

Inflammation plays central roles in key aspects of successful reproduction: ovulation, implantation and parturition. In this study we characterised the inflammatory profile of the rat placenta in late gestation with and without maternal glucocorticoid (dexamethasone) treatment.Placentas (n = 6/group) were collected from untreated (Con) rats at days 16 and 22 (term = day 23) and from dexamethasone-treated (Dex) rats at day 22. mRNA and protein expression was determined for enzymes of prostaglandin synthesis and metabolism (Ptgs-1, Ptgs-2, 15-Pgdh), pro-inflammatory cytokines (Tnf-α, Il-1β, Il-6), and the macrophage marker Emr-1 in the junctional (JZ) and labyrinth (LZ) zones of the placenta.Tnf-α, Il-1β and Il-6 mRNAs all increased (2- to 4-fold) in both placental zones between days 16 and 22 (P0.01). Ptgs-2 mRNA (30-fold; P0.01) and PTGS-2 protein (2.4-fold; P0.05) similarly increased in LZ. In contrast, 15-Pdgh expression increased in JZ but decreased in LZ; these changes were accompanied by decreased levels of PGE2 in the JZ and a trend towards increased LZ levels. Dex treatment inhibited fetal and placental growth, but had minimal effects on expression of Ptgs-1, Ptgs-2 or 15-Pdgh. Nevertheless, Dex treatment increased LZ PGE2 levels (5-fold, P0.01) at the end of gestation. Dex treatment increased Tnf-α mRNA expression in LZ (40%; P0.05), but modestly suppressed cytokine protein expression in JZ.These data demonstrate that the inflammatory state of the LZ increases near term coincident with the known increase in local glucocorticoid levels. This suggests the classic anti-inflammatory actions of glucocorticoids do not occur in the placental LZ.