220 research outputs found
Environmental Impact on the Southeast Limb of the Cygnus Loop
We analyze observations from the Chandra X-ray Observatory of the southeast
knot of the Cygnus Loop supernova remnant. In this region, the blast wave
propagates through an inhomogeneous environment. Extrinsic differences and
subsequent multiple projections along the line of sight rather than intrinsic
shock variations, such as fluid instabilities, account for the apparent
complexity of the images. Interactions between the supernova blast wave and
density enhancements of a large interstellar cloud can produce the
morphological and spectral characteristics. Most of the X-ray flux arises in
such interactions, not in the diffuse interior of the supernova remnant.
Additional observations at optical and radio wavelengths support this account
of the existing interstellar medium and its role in shaping the Cygnus Loop,
and they demonstrate that the southeast knot is not a small cloud that the
blast wave has engulfed. These data are consistent with rapid equilibration of
electron and ion temperatures behind the shock front, and the current blast
wave velocity v_{bw} approx 330 km/s. Most of this area does not show strong
evidence for non-equilibrium ionization conditions, which may be a consequence
of the high densities of the bright emission regions.Comment: To appear in ApJ, April 1, 200
Somatic symptom disorder in dermatology
Somatic symptom disorder (SSD) is defined by the prominence of somatic symptoms associated with abnormal thoughts, feelings, and behaviors related to the symptoms, resulting in significant distress and impairment. Individuals with these disorders are more commonly encountered in primary care and other medical settings, including dermatology practice, than in psychiatric and other mental health settings. What defines the thoughts, feelings, and behaviors as abnormal is that they are excessive, that is, out of proportion to other patients with similar somatic symptoms, and that they result in significant distress and impairment. SSD may occur with or without the presence of a diagnosable dermatologic disorder. When a dermatologic disorder is present, SSD should be considered when the patient is worrying too much about his or her skin, spending too much time and energy on it, and especially if the patient complains of many nondermatologic symptoms in addition. The differential diagnosis includes other psychiatric disorders, including depression, anxiety disorders, delusions of parasitosis, and body dysmorphic disorder
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Physiological, behavioral and subjective sadness reactivity in frontotemporal dementia subtypes.
Frontotemporal dementia (FTD), a neurodegenerative disease broadly characterized by socioemotional impairments, includes three clinical subtypes: behavioral variant FTD (bvFTD), semantic variant primary progressive aphasia (svPPA) and non-fluent variant primary progressive aphasia (nfvPPA). Emerging evidence has shown emotional reactivity impairments in bvFTD and svPPA, whereas emotional reactivity in nfvPPA is far less studied. In 105 patients with FTD (49 bvFTD, 31 svPPA and 25 nfvPPA) and 27 healthy controls, we examined three aspects of emotional reactivity (physiology, facial behavior and subjective experience) in response to a sad film. In a subset of the sample, we also examined the neural correlates of diminished aspects of reactivity using voxel-based morphometry. Results indicated that all three subtypes of FTD showed diminished physiological responding in respiration rate and diastolic blood pressure; patients with bvFTD and svPPA also showed diminished subjective experience, and no subtypes showed diminished facial behavior. Moreover, there were differences among the clinical subtypes in brain regions where smaller volumes were associated with diminished sadness reactivity. These results show that emotion impairments extend to sadness reactivity in FTD and underscore the importance of considering different aspects of sadness reactivity in multiple clinical subtypes for characterizing emotional deficits and associated neurodegeneration in FTD
Comorbidity, Pain, Utilization, and Psychosocial Outcomes in Older versus Younger Sickle Cell Adults: The PiSCES Project
Background. Patients with SCD now usually live well into adulthood. Whereas transitions into adulthood are now often studied, little is published about aging beyond the transition period. We therefore studied age-associated SCD differences in utilization, pain, and psychosocial variables. Methods. Subjects were 232 adults in the Pain in Sickle Cell Epidemiology Study (PiSCES). Data included demographics, comorbidity, and psychosocial measures. SCD-related pain and health care utilization were recorded in diaries. We compared 3 age groups: 16â25 (transition), 26â36 (younger adults), and 37â64 (older adults) years. Results. Compared to the 2 adult groups, the transition group reported fewer physical challenges via comorbidities, somatic complaints, and pain frequency, though pain intensity did not differ on crisis or noncrisis pain days. The transition group utilized opioids less often, made fewer ambulatory visits, and had better quality of life, but these differences disappeared after adjusting for pain and comorbidities. However, the transition group reported more use of behavioral coping strategies. Conclusion. We found fewer biological challenges, visits, and better quality of life, in transition-aged versus older adults with SCD, but more behavioral coping. Further study is required to determine whether age-appropriate health care, behavioral, or other interventions could improve age-specific life challenges of patients with SCD
Poor caregiver mental health predicts mortality of patients with neurodegenerative disease.
Dementia and other neurodegenerative diseases cause profound declines in functioning; thus, many patients require caregivers for assistance with daily living. Patients differ greatly in how long they live after disease onset, with the nature and severity of the disease playing an important role. Caregiving can also be extremely stressful, and many caregivers experience declines in mental health. In this study, we investigated the role that caregiver mental health plays in patient mortality. In 176 patient-caregiver dyads, we found that worse caregiver mental health predicted greater patient mortality even when accounting for key risk factors in patients (i.e., diagnosis, age, sex, dementia severity, and patient mental health). These findings highlight the importance of caring for caregivers as well as patients when attempting to improve patients' lives
The Rest-Frame Optical Spectrum of MS 1512-cB58
Moderate resolution, near-IR spectroscopy of MS1512-cB58 is presented,
obtained during commissioning of the the Near IR Spectrometer (NIRSPEC) on the
Keck II telescope. The strong lensing of this z=2.72 galaxy by the foreground
cluster MS1512+36 makes it the best candidate for detailed study of the
rest-frame optical properties of Lyman Break Galaxies.
A redshift of z=2.7290+/-0.0007 is inferred from the emission lines, in
contrast to the z=2.7233 calculated from UV observations of interstellar
absorption lines. Using the Balmer line ratios, we find an extinction of
E(B-V)=0.27. Using the line strengths, we infer an SFR=620+/-18 Msun/yr
(H_0=75, q_0=0.1, Lambda =0), a factor of 2 higher than that measured from
narrow-band imaging observations of the galaxy, but a factor of almost 4 lower
than the SFR inferred from the UV continuum luminosity. The width of the Balmer
lines yields a mass of M_vir=1.2x10^10 Msun. We find that the oxygen abundance
is 1/3 solar, in good agreement with other estimates of the metallicity.
However, we infer a high nitrogen abundance, which may argue for the presence
of an older stellar population.Comment: 14 pages, including 3 figures. Accepted for publication in ApJ
Letter
About AGN ionization echoes, thermal echoes, and ionization deficits in low redshift Lyman-alpha blobs
We report the discovery of 14 Lyα blobs (LABs) at z ⌠0.3, existing at least 4â7 billion years later in the Universe than all other LABs known. Their optical diameters are 20â70 kpc, and GALEX data imply Lyα luminosities of (0.4â6.3) Ă 1043 erg sâ1. Contrary to high-z LABs, they live in low-density areas. They are ionized by AGN, suggesting that cold accretion streams as a power source must deplete between z = 2 and 0.3. We also show that transient AGN naturally explain the ionization deficits observed in many LABs. Their Lyα and X-ray fluxes decorrelate below âČ106 years because of the delayed escape of resonantly scattering Lyα photons. High Lyα luminosities do not require currently powerful AGN, independent of obscuration. Chandra X-ray data reveal intrinsically weak AGN, confirming the luminous optical nebulae as impressive ionization echoes. For the first time, we also report mid-infrared thermal echoes from the dusty tori. We conclude that the AGN have faded by three to four orders of magnitude within the last 104â5 years, leaving fossil UV, optical and thermal radiation behind. The host galaxies belong to the group of previously discovered Green Bean galaxies (GBs). Gemini optical imaging reveals smooth spheres, mergers, spectacular outflows and ionization cones. Because of their proximity and high flux densities, GBs are perfect targets to study AGN feedback, mode switching and the Lyα escape. The fully calibrated, co-added optical FITS images are publicly available
Evaluation of intramuscular olanzapine and ziprasidone in the medically ill
Introduction: Despite the paucity of studies evaluating short-acting parenteral second-generation antipsychotics in the medically ill, their use in this population has increased. The purpose of this study was to characterize the use of IM olanzapine and ziprasidone in the medically ill at an academic medical center.
Methods: This is a retrospective medical record review of all patients who received IM olanzapine or ziprasidone on nonpsychiatric inpatient units at a large academic medical center from August 1, 2015 to July 31, 2017. The primary endpoint characterized the indication for use. Secondary endpoints included safety, effectiveness, and prescribing patterns.
Results: After exclusion criteria, a total of 100 patients were included in this study, predominantly white males with a mean age of 56 years. Seventy-four percent of patients received IM ziprasidone and 26% received IM olanzapine. The most common indications for use were agitation of nonpsychotic origin (40%) and delirium (33%). Patients received IM olanzapine and ziprasidone when their use was contraindicated (26.9% vs 9.5%, respectively).
Discussion: Intramuscular second-generation antipsychotics are increasingly being used in the medically ill for delirium and agitation. Our study confirms these were the most common indications for IM second-generation antipsychotic use in this population. Additionally, their use appeared to be well-tolerated, and no patient developed Torsades de Pointes even when combined with other agents that putatively increase QTc. Given the retrospective, single-center, nonrandomized design of this study, the safety and effectiveness of these parenteral second-generation antipsychotics in common causes of acute agitation should continue to be further evaluated
Health related quality of life in sickle cell patients: The PiSCES project
BACKGROUND: Sickle cell disease (SCD) is a chronic disease associated with high degrees of morbidity and increased mortality. Health-related quality of life (HRQOL) among adults with sickle cell disease has not been widely reported. METHODS: We administered the Medical Outcomes Study 36-item Short-Form to 308 patients in the Pain in Sickle Cell Epidemiology Study (PiSCES) to assess HRQOL. Scales included physical function, physical and emotional role function, bodily pain, vitality, social function, mental health, and general health. We compared scores with national norms using t-tests, and with three chronic disease cohorts: asthma, cystic fibrosis and hemodialysis patients using analysis of variance and Dunnett's test for comparison with a control. We also assessed whether SCD specific variables (genotype, pain, crisis and utilization) were independently predictive of SF-36 subscales, controlling for socio-demographic variables using regression. RESULTS: Patients with SCD scored significantly worse than national norms on all subscales except mental health. Patients with SCD had lower HRQOL than cystic fibrosis patients except for mental health. Scores were similar for physical function, role function and mental health as compared to asthma patients, but worse for bodily pain, vitality, social function and general health subscales. Compared to dialysis patients, sickle cell disease patients scored similarly on physical role and emotional role function, social functioning and mental health, worse on bodily pain, general health and vitality and better on physical functioning. Surprisingly, genotype did not influence HRQOL except for vitality. However, scores significantly decreased as pain levels increased. CONCLUSION: SCD patients experience health related quality of life worse than the general population, and in general, their scores were most similar to patients undergoing hemodialysis. Practitioners should regard their HRQOL as severely compromised. Interventions in SCD should consider improvements in health related quality of life as important outcomes
SPIRE imaging of M82: cool dust in the wind and tidal streams
M82 is a unique representative of a whole class of galaxies, starbursts with
superwinds, in the Very Nearby Galaxy Survey with Herschel. In addition, its
interaction with the M81 group has stripped a significant portion of its
interstellar medium from its disk. SPIRE maps now afford better
characterization of the far-infrared emission from cool dust outside the disk,
and sketch a far more complete picture of its mass distribution and energetics
than previously possible. They show emission coincident in projection with the
starburst wind and in a large halo, much more extended than the PAH band
emission seen with Spitzer. Some complex substructures coincide with the
brightest PAH filaments, and others with tidal streams seen in atomic hydrogen.
We subtract the far-infrared emission of the starburst and underlying disk from
the maps, and derive spatially-resolved far-infrared colors for the wind and
halo. We interpret the results in terms of dust mass, dust temperature, and
global physical conditions. In particular, we examine variations in the dust
physical properties as a function of distance from the center and the wind
polar axis, and conclude that more than two thirds of the extraplanar dust has
been removed by tidal interaction, and not entrained by the starburst wind.Comment: accepted in A&A Herschel special issu
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