187 research outputs found
Through a Smoother Lens: An expected absence of LCDM substructure detections from hydrodynamic and dark matter only simulations
A fundamental prediction of the cold dark matter cosmology is the existence
of a large number of dark subhalos around galaxies, most of which should be
entirely devoid of stars. Confirming the existence of dark substructures stands
among the most important empirical challenges in modern cosmology: if they are
found and quantified with the mass spectrum expected, then this would close the
door on a vast array of competing theories. But in order for observational
programs of this kind to reach fruition, we need robust predictions. Here we
explore substructure predictions for lensing using galaxy lens-like hosts at
z=0.2 from the Illustris simulations both in full hydrodynamics and dark matter
only. We quantify substructures more massive than ~ 10^9 M_sun, comparable to
current lensing detections derived from HST, Keck, and ALMA. The addition of
full hydrodynamics reduces the overall subhalo mass function by about a factor
of two. Even for the dark matter only runs, most (~ 85%) lines of sight through
projected cylinders of size close to an Einstein radius contain no
substructures larger than 10^9 M_sun. The fraction of empty sight lines rises
to ~ 95% in full physics simulations. This suggests we will likely need
hundreds of strong lensing systems suitable for substructure studies, as well
as predictions that include the effects of baryon physics on substructure, to
properly constrain cosmological models. Fortunately, the field is poised to
fulfill these requirements.Comment: 11 pages, 9 figure
A latent class analysis of parental bipolar disorder: examining associations with offspring psychopathology
Bipolar disorder (BD) is highly heterogeneous, and course variations are associated with patient outcomes. This diagnostic complexity challenges identification of patients in greatest need of intervention. Additionally, course variations have implications for offspring risk. First, latent class analysis (LCA) categorized parents with BD based on salient illness characteristics: BD type, onset age, polarity of index episode, pole of majority of episodes, rapid cycling, psychosis, anxiety comorbidity, and substance dependence. Fit indices favored three parental classes with some substantively meaningful patterns. Two classes, labeled “Earlier-Onset Bipolar-I” (EO-I) and “Earlier-Onset Bipolar-II” (EO-II), comprised parents who had a mean onset age in mid-adolescence, with EO-I primarily BD-I parents and EO-II entirely BD-II parents. The third class, labeled “Later-Onset BD” (LO) had an average onset age in adulthood. Classes also varied on probability of anxiety comorbidity, substance dependence, psychosis, rapid cycling, and pole of majority of episodes. Second, we examined rates of disorders in offspring (ages 4–33, Mage=13.46) based on parental latent class membership. Differences emerged for offspring anxiety disorders only such that offspring of EO-I and EO-II parents had higher rates, compared to offspring of LO parents, particularly for daughters. Findings may enhance understanding of BD and its nosologyThis study was funded by two Brain & Behavior Research Foundation (formerly NARSAD) Independent Investigator Awards (PI: Nierenberg), a Brain & Behavior Research Foundation Young Investigator Award (PI: Henin) generously supported in part by the SHINE Initiative, and an MGH Claflin Award (PI: Henin). We thank David A. Langer, Ph.D., Thomas M. Olino, Ph.D., and Meredith Lotz Wallace, Ph.D. for their consultation. (Brain & Behavior Research Foundation; Brain & Behavior Research Foundation Young Investigator Award; SHINE Initiative; MGH Claflin Award)Accepted manuscrip
Transdiagnostic treatment of bipolar disorder and comorbid anxiety using the Unified Protocol for Emotional Disorders: A pilot feasibility and acceptability trial
BACKGROUND
Comorbid anxiety in bipolar disorder (BD) is associated with greater illness severity, reduced treatment response, and greater impairment. Treating anxiety in the context of BD is crucial for improving illness course and outcomes. The current study examined the feasibility, acceptability and preliminary efficacy of the Unified Protocol (UP), a transdiagnostic cognitive behavioral therapy, as an adjunctive treatment to pharmacotherapy for BD and comorbid anxiety disorders.
METHODS
Twenty-nine patients with BD and at least one comorbid anxiety disorder were randomized to pharmacotherapy treatment-as-usual (TAU) or TAU with 18 sessions of the UP (UP+TAU). All patients completed assessments every four weeks to track symptoms, functioning, emotion regulation and temperament. Linear mixed-model regressions were conducted to track symptom changes over time and to examine the relationship between emotion-related variables and treatment response.
RESULTS
Satisfaction ratings were equivalent for both treatment groups. Patients in the UP+TAU group evidenced significantly greater reductions over time in anxiety and depression symptoms (Cohen's d's>0.80). Baseline levels of neuroticism, perceived affective control, and emotion regulation ability predicted magnitude of symptom change for the UP+TAU group only. Greater change in perceived control of emotions and emotion regulation skills predicted greater change in anxiety related symptoms.
LIMITATIONS
This was a pilot feasibility and acceptability trial; results should be interpreted with caution.
CONCLUSIONS
Treatment with the UP+TAU was rated high in patient satisfaction, and resulted in significantly greater improvement on indices of anxiety and depression relative to TAU. This suggests that the UP may be a feasible treatment approach for BD with comorbid anxiety.This work was supported by a Postdoctoral National Research Service Award from the National Institutes of Health [F32 MH098490] to K. Ellard. (F32 MH098490 - Postdoctoral National Research Service Award from the National Institutes of Health)Accepted manuscrip
Pushing the Limits of Detectability: Mixed Dark Matter from Strong Gravitational Lenses
One of the frontiers for advancing what is known about dark matter lies in
using strong gravitational lenses to characterize the population of the
smallest dark matter halos. There is a large volume of information in strong
gravitational lens images -- the question we seek to answer is to what extent
we can refine this information. To this end, we forecast the detectability of a
mixed warm and cold dark matter scenario using the anomalous flux ratio method
from strong gravitational lensed images. The halo mass function of the mixed
dark matter scenario is suppressed relative to cold dark matter but still
predicts numerous low-mass dark matter halos relative to warm dark matter.
Since the strong lens signal is a convolution over a range of dark matter halo
masses and since the signal is sensitive to the specific configuration of dark
matter halos, not just the halo mass function, degeneracies between different
forms of suppression in the halo mass function, relative to cold dark matter,
can arise. We find that, with a set of lenses with different configurations of
the main deflector and hence different sensitivities to different mass ranges
of the halo mass function, the different forms of suppression of the halo mass
function between the warm dark matter model and the mixed dark matter model can
be distinguished with lenses with Bayesian odds of 29.4:1.Comment: 8 pages, 7 figure
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Nutrition, Exercise, and Wellness Treatment in bipolar disorder: proof of concept for a consolidated intervention
Background: This pilot study examines the proof of concept of a consolidated Nutrition, Exercise, and Wellness Treatment (NEW Tx) for overweight individuals with bipolar disorder. Findings: Five participants completed NEW Tx, a 20-week individual cognitive behavioral therapy-based treatment comprising three modules: Nutrition teaches appropriate serving sizes and balanced diet; Exercise emphasizes increasing weekly physical activity; Wellness focuses on skills for healthy decision-making. Participants attended most sessions and reported high satisfaction with the treatment. Participants’ weight, cholesterol and trigyclerides decreased over the study duration as well as number of daily calories and sugar intake. We found that weekly exercise duration more than tripled over the study duration and depressive symptoms and functioning have improved. Conclusions: These results offer proof of concept that consolidated NEW Tx is feasible and acceptable and has the potential to improve nutrition, exercise, wellness, and mood symptoms in bipolar disorder. Future iterations of NEW Tx will reflect the strengths and lessons learned from this study
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Medication disposal practices: Increasing patient and clinician education on safe methods
Recent research suggests that the nation’s water supply is contaminated with trace pharmaceuticals that exert a negative environmental and public health impact. Incorrect medication disposal methods (e.g. flushing medications down the toilet or drain) are a significant factor contributing to the presence of medication compounds in the aquatic environment. In this commentary, we provide a summary of the existing data on pharmaceuticals in the nation’s water as well as the role of improper medication disposal methods on water contamination. We discuss statistics on improper medication disposal practices among patients and clinicians as well as recent advances in proper medication disposal methods as a solution to this problem. Currently, many patients and clinicians are not aware of proper medication disposal practices. We summarize the importance of patient and clinician education in advancing environmental-safe medication disposal methods
Stars made in outflows may populate the stellar halo of the Milky Way
We study stellar-halo formation using six Milky-Way-mass galaxies in FIRE-2 cosmological zoom simulations. We find that 5−40 per cent of the outer (50–300 kpc) stellar halo in each system consists of in-situ stars that were born in outflows from the main galaxy. Outflow stars originate from gas accelerated by superbubble winds, which can be compressed, cool, and form co-moving stars. The majority of these stars remain bound to the halo and fall back with orbital properties similar to the rest of the stellar halo at z = 0. In the outer halo, outflow stars are more spatially homogeneous, metal-rich, and alpha-element-enhanced than the accreted stellar halo. At the solar location, up to ∼10 per cent of our kinematically identified halo stars were born in outflows; the fraction rises to as high as ∼40 per cent for the most metal-rich local halo stars ([Fe/H] >−0.5). Such stars can be retrograde and create features similar to the recently discovered Milky Way ‘Splash’ in phase space. We conclude that the Milky Way stellar halo could contain local counterparts to stars that are observed to form in molecular outflows in distant galaxies. Searches for such a population may provide a new, near-field approach to constraining feedback and outflow physics. A stellar halo contribution from outflows is a phase-reversal of the classic halo formation scenario of Eggen, Lynden-Bell & Sandange, who suggested that halo stars formed in rapidly infalling gas clouds. Stellar outflows may be observable in direct imaging of external galaxies and could provide a source for metal-rich, extreme-velocity stars in the Milky Way
Behavioral Indicators on a Mobile Sensing Platform Predict Clinically Validated Psychiatric Symptoms of Mood and Anxiety Disorders
Background: There is a critical need for real-time tracking of behavioral indicators of mental disorders. Mobile sensing platforms that objectively and noninvasively collect, store, and analyze behavioral indicators have not yet been clinically validated or scalable.
Objective: The aim of our study was to report on models of clinical symptoms for post-traumatic stress disorder (PTSD) and depression derived from a scalable mobile sensing platform.
Methods: A total of 73 participants (67% [49/73] male, 48% [35/73] non-Hispanic white, 33% [24/73] veteran status) who reported at least one symptom of PTSD or depression completed a 12-week field trial. Behavioral indicators were collected through the noninvasive mobile sensing platform on participants’ mobile phones. Clinical symptoms were measured through validated clinical interviews with a licensed clinical social worker. A combination hypothesis and data-driven approach was used to derive key features for modeling symptoms, including the sum of outgoing calls, count of unique numbers texted, absolute distance traveled, dynamic variation of the voice, speaking rate, and voice quality. Participants also reported ease of use and data sharing concerns.
Results: Behavioral indicators predicted clinically assessed symptoms of depression and PTSD (cross-validated area under the curve [AUC] for depressed mood=.74, fatigue=.56, interest in activities=.75, and social connectedness=.83). Participants reported comfort sharing individual data with physicians (Mean 3.08, SD 1.22), mental health providers (Mean 3.25, SD 1.39), and medical researchers (Mean 3.03, SD 1.36).
Conclusions: Behavioral indicators passively collected through a mobile sensing platform predicted symptoms of depression and PTSD. The use of mobile sensing platforms can provide clinically validated behavioral indicators in real time; however, further validation of these models and this platform in large clinical samples is needed.United States. Defense Advanced Research Projects Agency (contract N66001-11-C-4094
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