49 research outputs found

    Accretion, Outflows, and Winds of Magnetized Stars

    Full text link
    Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can take to flow onto the star. These paths are different in stars with different magnetospheres and periods of rotation. External field lines of the magnetosphere may inflate and produce favorable conditions for outflows from the disk-magnetosphere boundary. Outflows can be particularly strong in the propeller regime, wherein a star rotates more rapidly than the inner disk. Outflows may also form at the disk-magnetosphere boundary of slowly rotating stars, if the magnetosphere is compressed by the accreting matter. In isolated, strongly magnetized stars, the magnetic field can influence formation and/or propagation of stellar wind outflows. Winds from low-mass, solar-type stars may be either thermally or magnetically driven, while winds from massive, luminous O and B type stars are radiatively driven. In all of these cases, the magnetic field influences matter flow from the stars and determines many observational properties. In this chapter we review recent studies of accretion, outflows, and winds of magnetized stars with a focus on three main topics: (1) accretion onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and (3) winds from isolated massive magnetized stars. We show results obtained from global magnetohydrodynamic simulations and, in a number of cases compare global simulations with observations.Comment: 60 pages, 44 figure

    How do patient-reported outcome measures affect treatment intensification and patient satisfaction in the management of psoriatic arthritis? A cross sectional study of 503 patients

    Get PDF
    Objectives The AsseSSing Impact in pSoriatic Treatment (ASSIST) study investigated prescribing in routine PsA care and whether the patient-reported outcome—PsA Impact of Disease questionnaire (PsAID-12)—impacted treatment. This study also assessed a range of patient and clinician factors and their relationship to PsAID-12 scoring and treatment modification. Methods Patients with PsA were selected across the UK and Europe between July 2021 and March 2022. Patients completed the PsAID questionnaire and the results were shared with their physician. Patient characteristics, disease activity, current treatment methods, treatment strategies, medication changes and patient satisfaction scores were recorded. Results A total of 503 patients were recruited. Some 36.2% had changes made to treatment, and 88.8% of these had treatment escalation. Overall, the mean PsAID-12 score was higher for patients with treatment escalation; increase in PSAID-12 score is associated with increased odds of treatment escalation (odds ratio 1.58; P < 0.0001). However, most clinicians reported that PsAID-12 did not impact their decision to escalate treatment, instead supporting treatment reduction decisions. Physician’s assessment of disease activity had the most statistically significant effect on likelihood of treatment escalation (odds ratio 2.68, per 1-point score increase). Escalation was more likely in patients not treated with biologic therapies. Additional factors associated with treatment escalation included: patient characteristics, physician characteristics, disease activity and disease impact. Conclusion This study highlights multiple factors impacting treatment decision-making for individuals with PsA. PsAID-12 scoring correlates with multiple measures of disease severity and odds of treatment escalation. However, most clinicians reported that the PsAID-12 did not influence treatment escalation decisions. Psoriatic Arthritis Impact of Disease (PsAID) scoring could be used to increase confidence in treatment de-escalation

    A joint Fermi-GBM and Swift-BAT analysis of gravitational-wave candidates from the third gravitational-wave observing run

    Get PDF
    We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers

    Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

    Get PDF
    The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

    Constraints on the cosmic expansion history from GWTC–3

    Get PDF
    We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H(z), including its current value, the Hubble constant H0. Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H(z). The source mass distribution displays a peak around 34 M⊙, followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H(z) measurement, yielding H0=688+12km  s1Mpc1{H}_{0}={68}_{-8}^{+12}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1} (68% credible interval) when combined with the H0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+, statistically marginalizing over the redshifts of each event's potential hosts. Assuming a fixed BBH population, we estimate a value of H0=686+8km  s1Mpc1{H}_{0}={68}_{-6}^{+8}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1} with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H0) is the well-localized event GW190814

    GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

    Get PDF
    We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

    A joint Fermi-GBM and Swift-BAT analysis of gravitational-wave candidates from the third gravitational-wave observing run

    Get PDF
    We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers

    Altered MicroRNA Expression Profile in Human Pituitary GH Adenomas: Down-Regulation of miRNA Targeting HMGA1, HMGA2, and E2F1

    No full text
    Context: MicroRNA (miRNA) are an important class of regulators of gene expression. Altered miRNA expression has been constantly found in human neoplasias and plays an important role in the process of carcinogenesis. Objective: The aim of this study was to identify specific miRNA whose expression is altered in GH-secreting pituitary adenomas. Design: Using a miRNACHIP microarray, we have analyzed the miRNA expression profile of human GH adenomas vs. normal pituitary gland. Results: We report the identification of a set of miRNA, including miR-34b, miR-326, miR-432, miR-548c-3p, miR-570, and miR-603, drastically and constantly down-regulated in GH adenomas. Wedemonstrate that thesemiRNAtarget genes such as high-mobility groupA1(HMGA1),HMGA2, and E2F1, whose overexpression and/or activation plays a critical role in pituitary tumorigenesis. We also show that the enforced expression of the down-regulated miRNA has a negative role on the growth regulation of pituitary adenoma cells. Finally, an inverse correlation is found between the expression of these miRNA and HMGA1 and HMGA2 protein levels in GH adenomas. Conclusion: Our study identifies a specific subset of miRNA, whose down-regulation might contribute to pituitary tumorigenesis

    Hipogonadismo e função tireoidiana em ratas hipertireóideas e eutireóideas Hypogonadism and thyroid function in hyper and euthyroid rats

    No full text
    A influência do hipogonadismo sobre a função tireoidiana de ratas hipertireóideas e eutireóideas foi medida com base no perfil sérico dos hormônios tireoidianos, dos esteróides ovarianos e do TSH e na histomorfometria da tireóide. Ratas Wistar, com cinco meses de idade, castradas, foram mantidas em estado eutireóideo ou hipertireóideo por períodos de 30, 60 e 90 dias. Um grupo não castrado foi mantido nas mesmas condições e serviu como controle. O hipertireoidismo foi induzido mediante a administração diária 50µg de L-tiroxina, por sonda gástrica. Ao final de cada período, nove ratas por grupo tiveram suas tireóides inspecionadas, pesadas e processadas para avaliação histomorfométrica e o plasma sangüíneo colhido para dosagem de estradiol, progesterona, T4 total, T4 livre, T3 total e TSH. O hipogonadismo não alterou os valores de T3 total e de TSH, mas aumentou significativamente as concentrações de T4 livre, independente do estado hipertireóideo ou eutireóideo. As concentrações de T4 total sofreram influência da castração apenas no grupo hipertireóideo. O peso das tireóides não sofreu influência do hipogonadismo, mas a altura do epitélio folicular nos animais eutireóideos variou ao longo do experimento, apresentando-se maior aos 30 e 90 dias e menor aos 60 dias. Não se observou correlação entre os níveis de estrógeno e as variáveis estudadas, mas os níveis de progesterona foram inversamente proporcionais à elevação dos níveis de T4 total e T4 livre. Concluiu-se que o hipogonadismo altera a histomorfometria da tireoide em indivíduos eutireóideos, aumenta os valores plasmáticos de T4 livre independentemente do estado funcional da tireóide e potencializa a elevação de T4 total no hipertireoidismo, provavelmente sob influência do hipoprogesteronismo e não do hipoestrogenismo.<br>The effects of hypogonadism on thyroid function of hyper and euthyroid rats were measured based on plasmatic profile of thyroid hormones, ovarian steroids, TSH and thyroid histomorphometry. A group of five-month-old ovariectomized Wistar rats were maintained at hyper or euthyroid state for 30, 60 and 90 days. A group of non castrated was used as control. The hyperthyroidism was induced by gastric infusion of L-tiroxin 50µg daily. At the end of each period nine rats of each group were sacrificed, the blood plasma collected and the thyroid inspected, measured and processed for histomorphometric analyses. In blood plasma the concentrations of estradiol, progesterone, total and free tiroxin, total and free T3 and TSH were determined. The hypogonadism did not alter the values of free T3 and TSH but was able to rise free tiroxin in both hyper and euthyroid states. Total tiroxin levels were affected by castration, but only in the hyperthyroid state. Folicular epithelium height presented variations along the experiment in euthyroid individuals although these did not influence thyroid weight. No correlations between estrogen and any other variables were observed, but the progesterone levels were conversely proportional to the total and free tiroxin levels. It was concluded that hypogonadism alter the histomorphometric patterns of thyroid gland in euthyroid individuals, rise the plasmatic levels of free tiroxin regardless the functional state of thyroid gland and powered the total tyroxin rise in hyperthyroidism, probably due to the influence of hypoprogesteronism but not to the hypoestrogenism
    corecore