344 research outputs found
EXPRES IV: Two Additional Planets Orbiting Coronae Borealis Reveal Uncommon System Architecture
Thousands of exoplanet detections have been made over the last twenty-five
years using Doppler observations, transit photometry, direct imaging, and
astrometry. Each of these methods is sensitive to different ranges of orbital
separations and planetary radii (or masses). This makes it difficult to fully
characterize exoplanet architectures and to place our solar system in context
with the wealth of discoveries that have been made. Here, we use the EXtreme
PREcision Spectrograph (EXPRES) to reveal planets in previously undetectable
regions of the mass-period parameter space for the star Coronae
Borealis. We add two new planets to the previously known system with one hot
Jupiter in a 39-day orbit and a warm super-Neptune in a 102-day orbit. The new
detections include a temperate Neptune planet ( M)
in a 281.4-day orbit and a hot super-Earth ( M) in a
12.95-day orbit. This result shows that details of planetary system
architectures have been hiding just below our previous detection limits; this
signals an exciting era for the next generation of extreme precision
spectrographs.Comment: Accepted to AJ; 20 pages, 13 figures, 5 Table
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Expression of SMARCD1 interacts with age in association with asthma control on inhaled corticosteroid therapy.
BackgroundGlobal gene expression levels are known to be highly dependent upon gross demographic features including age, yet identification of age-related genomic indicators has yet to be comprehensively undertaken in a disease and treatment-specific context.MethodsWe used gene expression data from CD4+ lymphocytes in the Asthma BioRepository for Integrative Genomic Exploration (Asthma BRIDGE), an open-access collection of subjects participating in genetic studies of asthma with available gene expression data. Replication population participants were Puerto Rico islanders recruited as part of the ongoing Genes environments & Admixture in Latino Americans (GALA II), who provided nasal brushings for transcript sequencing. The main outcome measure was chronic asthma control as derived by questionnaires. Genomic associations were performed using regression of chronic asthma control score on gene expression with age in years as a covariate, including a multiplicative interaction term for gene expression times age.ResultsThe SMARCD1 gene (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 1) interacted with age to influence chronic asthma control on inhaled corticosteroids, with a doubling of expression leading to an increase of 1.3 units of chronic asthma control per year (95% CI [0.86, 1.74], p = 6 × 10- 9), suggesting worsening asthma control with increasing age. This result replicated in GALA II (p = 3.8 × 10- 8). Cellular assays confirmed the role of SMARCD1 in glucocorticoid response in airway epithelial cells.ConclusionFocusing on age-dependent factors may help identify novel indicators of asthma medication response. Age appears to modulate the effect of SMARCD1 on asthma control with inhaled corticosteroids
Measured Spin-Orbit Alignment of Ultra-Short Period Super-Earth 55 Cancri e
A planet's orbital alignment places important constraints on how a planet
formed and consequently evolved. The dominant formation pathway of ultra-short
period planets ( day) is particularly mysterious as such planets most
likely formed further out, and it is not well understood what drove their
migration inwards to their current positions. Measuring the orbital alignment
is difficult for smaller super-Earth/sub-Neptune planets, which give rise to
smaller amplitude signals. Here we present radial velocities across two
transits of 55 Cancri e, an ultra-short period Super-Earth, observed with the
Extreme Precision Spectrograph (EXPRES). Using the classical
Rossiter-McLaughlin (RM) method, we measure 55 Cnc e's sky-projected stellar
spin-orbit alignment (i.e., the projected angle between the planet's orbital
axis and its host star's spin axis) to be with an unprojected angle of . The best-fit RM model to the EXPRES data has a radial velocity
semi-amplitude of just . The spin-orbit
alignment of 55 Cnc e favors dynamically gentle migration theories for
ultra-short period planets, namely tidal dissipation through low-eccentricity
planet-planet interactions and/or planetary obliquity tides.Comment: 12 pages, 4 figures, published in Nature Astronom
Mixture models as a method for comparative sociality: social networks and demographic change in resident killer whales
In studies of social behaviour, social bonds are usually inferred from rates of interaction or association. This approach has revealed many important insights into the proximate formation and ultimate function of animal social structures. However, it remains challenging to compare social structure between systems or time-points because extrinsic factors, such as sampling methodology, can also influence the observed rate of association. As a consequence of these methodological challenges, it is difficult to analyse how patterns of social association change with demographic processes, such as the death of key social partners. Here we develop and illustrate the use of binomial mixture models to quantitatively compare patterns of social association between networks. We then use this method to investigate how patterns of social preferences in killer whales respond to demographic change. Resident killer whales are bisexually philopatric, and both sexes stay in close association with their mother in adulthood. We show that mothers and daughters show reduced social association after the birth of the daughter’s first offspring, but not after the birth of an offspring to the mother. We also show that whales whose mother is dead associate more with their opposite sex siblings and with their grandmother than whales whose mother is alive. Our work demonstrates the utility of using mixture models to compare social preferences between networks and between species. We also highlight other potential uses of this method such as to identify strong social bonds in animal populations
Episodic Therapy for Genital Herpes in Sub-Saharan Africa: A Pooled Analysis from Three Randomized Controlled Trials
BACKGROUND: A randomized controlled trial in South Africa found a beneficial effect of acyclovir on genital ulcer healing, but no effect was seen in trials in Ghana, Central African Republic and Malawi. The aim of this paper is to assess whether the variation in impact of acyclovir on ulcer healing in these trials can be explained by differences in the characteristics of the study populations. METHODOLOGY/PRINCIPAL FINDINGS: Pooled data were analysed to estimate the impact of acyclovir on the proportion of ulcers healed seven days after randomisation by HIV/CD4 status, ulcer aetiology, size and duration before presentation; and impact on lesional HIV-1. Risk ratios (RR) were estimated using Poisson regression with robust standard errors. Of 1478 patients with genital ulcer, most (63%) had herpetic ulcers (16% first episode HSV-2 ulcers), and a further 3% chancroid, 2% syphilis, 0.7% lymphogranuloma venereum and 31% undetermined aetiology. Over half (58%) of patients were HIV-1 seropositive. The median duration of symptoms before presentation was 6 days. Patients on acyclovir were more likely to have a healed ulcer on day 7 (63% vs 57%, RR = 1.08, 95% CI 0.98-1.18), shorter time to healing (p = 0.04) and less lesional HIV-1 RNA (p = 0.03). Small ulcers (<50 mm(2)), HSV-2 ulcers, first episode HSV-2 ulcers, and ulcers in HIV-1 seropositive individuals responded best but the better effectiveness in South Africa was not explained by differences in these factors. CONCLUSIONS/SIGNIFICANCE: There may be slight benefit in adding acyclovir to syndromic management in settings where most ulcers are genital herpes. The stronger effect among HIV-1 infected individuals suggests that acyclovir may be beneficial for GUD/HIV-1 co-infected patients. The high prevalence in this population highlights that genital ulceration in patients with unknown HIV status provides a potential entry point for provider-initiated HIV testing
Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets
Mass, radius, and age measurements of young (<100 Myr) planets have the power
to shape our understanding of planet formation. However, young stars tend to be
extremely variable in both photometry and radial velocity, which makes
constraining these properties challenging. The V1298 Tau system of four ~0.5
Rjup planets transiting a pre-main sequence star presents an important, if
stress-inducing, opportunity to directly observe and measure the properties of
infant planets. Su\'arez-Mascare\~no et al. (2021) published
radial-velocity-derived masses for two of the V1298 Tau planets using a
state-of-the-art Gaussian Process regression framework. The planetary densities
computed from these masses were surprisingly high, implying extremely rapid
contraction after formation in tension with most existing planet formation
theories. In an effort to further constrain the masses of the V1298 Tau
planets, we obtained 36 RVs using Keck/HIRES, and analyzed them in concert with
published RVs and photometry. Through performing a suite of cross validation
tests, we found evidence that the preferred model of SM21 suffers from
overfitting, defined as the inability to predict unseen data, rendering the
masses unreliable. We detail several potential causes of this overfitting, many
of which may be important for other RV analyses of other active stars, and
recommend that additional time and resources be allocated to understanding and
mitigating activity in active young stars such as V1298 Tau.Comment: 26 pages, 12 figures; published in A
Internet-based treatment for PTSD reduces distress and facilitates the development of a strong therapeutic alliance: a randomized controlled clinical trial
BACKGROUND: The present study was designed to evaluate the efficacy of an internet-based therapy (Interapy) for Posttraumatic Stress Disorder (PTSD) in a German speaking population. Also, the quality of the online therapeutic relationship, its development and its relevance as potential moderator of the treatment effects was investigated. METHOD: Ninety-six patients with posttraumatic stress reactions were allocated at random to ten sessions of Internet-based cognitive behavioural therapy (CBT) conducted over a 5-week period or a waiting list control group. Severity of PTSD was the primary outcome. Secondary outcome variables were depression, anxiety, dissociation and physical health. Follow-up assessments were conducted at the end of treatment and 3 months after treatment. RESULTS: From baseline to post-treatment assessment, PTSD severity and other psychopathological symptoms were significantly improved for the treatment group (intent-to-treat group x time interaction effect size d = 1.40). Additionally, patients of the treatment condition showed significantly greater reduction of co-morbid depression and anxiety as compared to the waiting list condition. These effects were sustained during the 3-months follow-up period. High ratings of the therapeutic alliance and low drop-out rates indicated that a positive and stable therapeutic relationship could be established online. Significant improvement of the online working alliance in the course of treatment and a substantial correlation between the quality of the online relationship at the end of treatment and treatment outcome emerged. CONCLUSION: Interapy proved to be a viable treatment alternative for PTSD with large effect sizes and sustained treatment effects. A stable and positive online therapeutic relationship can be established through the Internet which improved during the treatment process. TRIAL REGISTRATION: Australian Clinical Trials Registry ACTRN012606000401550
International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe
In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible
The possibility of critical realist randomised controlled trials.
BACKGROUND: Some realists have criticised randomised controlled trials for their inability to explain the causal relations that they identify; to take into account the influence of the social context of the interventions they evaluate; and to account for individual difference. However, among realists, there is controversy over whether it is possible to improve trials by making them realist, or whether realism and the philosophical assumptions underlying trials are incompatible. This paper contributes to the debate in Trials on this issue. The debate thus far has concentrated on the possibility of combining trial methodology with that of realist evaluation. MAIN BODY: We concur with the contention that it is not feasible to combine randomised controlled trial design with the realist evaluation approach. However, we argue that a different variant of realism, critical realism, provides a more appropriate theoretical grounding for realist trials. In contrast to realist evaluation, which regards social mechanisms as an amalgam of social resources and people's reasoning, critical realism insists on their distinction. It does so on the basis of its assertion of the need to distinguish between social structures (in which resources lie) and human agency (which is at least partly guided by reasoning). From this perspective, conceiving of social mechanisms as external to participants can be seen as a valid methodological strategy for supplementing the exclusive concentration of trials on outcomes. While accepting realist evaluation's insistence that causality in open systems involves a configuration of multiple generative mechanisms, we adopt the critical realist interpretation of the experimental method, which sees it as creating artificial closure in order to identify the effects of specific causal mechanisms. If randomised controlled trials can be regarded as epidemiological proxies that substitute probabilistic controls over extraneous factors for closed experiments, their examination of the powers of discrete mechanisms through observation of the variation of outcomes is appropriate. CONCLUSION: While there are still issues to be resolved, critical realist randomised controlled trials are possible and have the potential to overcome some of the difficulties faced by traditional trial designs in accounting for the influence of social context and individual interpretation
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