45 research outputs found
Electron Micro Bursts as a Mechanism of Electron Loss Via Wave-Particle Interactions
Electron microbursts are rapid fluctuations of electron fluxes occurring on time scales of milliseconds. They are thought be due to scattering into the loss cone by plasma waves of various types from chorus to the recently observed large amplitude whistlers. They may be a major process of loss of realtivistic electrons from the Earth's outer radiation belts. One of the key issues that new mission s such as RBSP will address is to understand the loss of relativistic electrons. The SAMPEX mission launched in 1992 and still collecting data has the HILT sensor onboard with the capability of measuring> 1 MeV electrons with a high time resolution of 20 milliseconds suited admirably for the study of microbursts. We will use the data collected by the HILT for over a decade to characterize the relationship between electron microbursts and macroscopic electron decay lifetimes. With the launch of RBSP it is expected that SAMPEX will continue to collect data and overlap with RBSP. The latter will provide valuable information regarding plasma waves which coupled with low altitude measurements of microbursts may help elucidate details of the physics of electron loss from the radiation belt
Antipsychotic Prescribing Pathways, Polypharmacy, and Clozapine Use in Treatment of Schizophrenia
Objective
To ensure optimal care for patients with schizophrenia, antipsychotic medications must be appropriately prescribed and used. Therefore, the primary objectives of this study were to identify and describe pathways for antipsychotic prescribing, assess the consistency of observed pathways with treatment guidelines, and describe variability across facilities.
Methods
Data from Veterans Affairs administrative data sets from fiscal year (FY) 2003 to FY 2007 were gathered for analysis in this retrospective cohort study of antipsychotic prescribing pathways among 13 facilities across two regional networks. Patients with a new episode of care for schizophrenia or schizoaffective disorder in FY 2005 were identified, and antipsychotic prescribing history was obtained for two years before and after the index diagnosis. Demographic characteristics and distribution of comorbidities were assessed. Median medical center rates of polypharmacy were calculated and compared with Fisher’s exact test.
Results
Of 1,923 patients with a new episode of schizophrenia care, 1,003 (52%) had complete data on prescribing pathways. A majority (74%) of patients were prescribed antipsychotic monotherapy, and 19% received antipsychotic polypharmacy. Of patients receiving antipsychotic polypharmacy, 65% began polypharmacy within 90 days of starting any antipsychotic treatment. There was a fourfold difference in polypharmacy across facilities. Antipsychotic polypharmacy was not associated with geographic location or medical center patient volume. Clozapine utilization was low (0%–2%).
Conclusions
Retrospective examination of longitudinal prescribing patterns identified multiple antipsychotic prescribing pathways. Although most patients received guideline-concordant care, antipsychotic polypharmacy was commonly used as initial treatment, and there was substantial variability among facilities. Study findings suggest the utility of secondary data to assess treatment adaptation or switching for practical clinical trials
Antipsychotic Prescribing Pathways, Polypharmacy, and Clozapine Use in Treatment of Schizophrenia
Dichomitus squalens partially tailors its molecular responses to the composition of solid wood
White-rot fungi, such as Dichomitus squalens, degrade all wood components and inhabit mixed-wood forests containing both soft- and hardwood species. In this study, we evaluated how D. squalens responded to the compositional differences in softwood [guaiacyl (G) lignin and higher mannan content] and hardwood [syringyl/guaiacyl (S/G) lignin and higher xylan content] using semi-natural solid cultures. Spruce (softwood) and birch (hardwood) sticks were degraded by D. squalens as measured by oxidation of the lignins using 2D-NMR. The fungal response as measured by transcriptomics, proteomics and enzyme activities showed a partial tailoring to wood composition. Mannanolytic transcripts and proteins were more abundant in spruce cultures, while a proportionally higher xylanolytic activity was detected in birch cultures. Both wood types induced manganese peroxidases to a much higher level than laccases, but higher transcript and protein levels of the manganese peroxidases were observed on the G-lignin rich spruce. Overall, the molecular responses demonstrated a stronger adaptation to the spruce rather than birch composition, possibly because D. squalens is mainly found degrading softwoods in nature, which supports the ability of the solid wood cultures to reflect the natural environment.Peer reviewe
Prevalence of dual sensory impairment and its association with traumatic brain injury and blast exposure in OEF/OIF Veterans
Background: Many service members deployed to the Afghanistan and Iraq theatre of
operations are returning with multiple injuries, including traumatic brain injury (TBI) and
sensory impairment. Studies of sensory impairment among patients with TBI have focused
either on the auditory or visual modality. However, their co-prevalence, termed dual sensory
impairment (DSI), is not well-documented. We examined self-reported rates of auditory and
visual impairment in Afghanistan and Iraq war Veterans receiving TBI evaluations
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1631The Impact of Obesity of Clostidium difficile Recurrence
Determinants of Utilization and Cost of VHA Care by OEF/OIF Veterans Screened for Mild Traumatic Brain Injury
The article of record as published may be found at http://dx.doi.org/10.7205/MILMED-D-13-00559Objective: To determine the demographic and service characteristics that differentially impact utilization
and cost of Veterans Health Administration (VHA) services for Operation Enduring Freedom and Operation Iraq Freedom
(OEF/OIF) Veterans screened or evaluated for traumatic brain injury (TBI). Setting: We examined Department of Defense
(DoD) and VHA administrative records of OEF/OIF Veterans who were screened or evaluated for TBI. Participants: Our
study population was OEF/OIF Veterans who separated from DoD in Fiscal Years 2003–2009 and who were screened or
evaluated in VHA for TBI between October 2008 and July 2009. Design: We describe the demographics and service
characteristics of separated Veterans and those who accessed the VHA. We report the cost of VHA utilization and estimate
a probit regression model to assess determinants of VHA utilization and costs by OEF/OIF Veterans screened and
evaluated for TBI by VHA. Results: Females and Veterans older than 37 years utilize VHA services more intensely.
Across all services, the Reserve Components utilize health services more than the Active Components placing more
demand on VHA for services. Conclusion: VHA utilization and costs is impacted by the demographic and service
characteristics of Veterans. The variation in Veteran groups incurring higher costs and utilization indicates different usage
patterns of VHA services by each group with implications for patient load as the DoD deploys higher numbers of females
and the Reserve Components.Office of Research and DevelopmentHealth Services R&D ServiceDepartment of Veterans AffairsServices Career Development Award (CDA 10-029)Department of Veterans Affairs SDR 08-405
Concordance of clinician judgment of mild traumatic brain injury history with a diagnostic standard
The article of record as published may be located at http://dx.doi.org/10.1682/JRRD.2013.05.0115The concordance of Department of Veterans Affairs
(VA) clinician judgment of mild traumatic brain injury (mTBI)
history with American Congress of Rehabilitation Medicine
(ACRM)-based criteria was examined for Operation Iraqi Freedom
(OIF) and Operation Enduring Freedom (OEF) Veterans. In
order to understand inconsistencies in agreement, we also examined
the associations between evaluation outcomes and conceptually
relevant patient characteristics, deployment-related events,
current self-reported health symptoms, and suspected psychiatric
conditions. The Veteran sample comprised 14,026 OIF/OEF VA
patients with deployment-related mTBI history (n = 9,858) or no
history of mTBI (n = 4,168) as defined by ACRM-based criteria.
In the majority of cases (76.0%), clinician judgment was in agreement
with the ACRM-based criteria. The most common inconsistency
was between clinician judgment (no) and ACRM-based
criteria (yes) for 21.3% of the patients. Injury etiology, current
self-reported health symptoms, and suspected psychiatric conditions
were additional factors associated with clinician diagnosis
and ACRM-based criteria disagreement. Adherence to established
diagnostic guidelines is essential for accurate determination
of mTBI history and for understanding the extent to which mTBI
symptoms resolve or persist over time in OIF/OEF Veterans
Concordance of clinician judgment of mild traumatic brain injury history with a diagnostic standard
The article of record as published may be located at http://dx.doi.org/10.1682/JRRD.2013.05.0115The concordance of Department of Veterans Affairs
(VA) clinician judgment of mild traumatic brain injury (mTBI)
history with American Congress of Rehabilitation Medicine
(ACRM)-based criteria was examined for Operation Iraqi Freedom
(OIF) and Operation Enduring Freedom (OEF) Veterans. In
order to understand inconsistencies in agreement, we also examined
the associations between evaluation outcomes and conceptually
relevant patient characteristics, deployment-related events,
current self-reported health symptoms, and suspected psychiatric
conditions. The Veteran sample comprised 14,026 OIF/OEF VA
patients with deployment-related mTBI history (n = 9,858) or no
history of mTBI (n = 4,168) as defined by ACRM-based criteria.
In the majority of cases (76.0%), clinician judgment was in agreement
with the ACRM-based criteria. The most common inconsistency
was between clinician judgment (no) and ACRM-based
criteria (yes) for 21.3% of the patients. Injury etiology, current
self-reported health symptoms, and suspected psychiatric conditions
were additional factors associated with clinician diagnosis
and ACRM-based criteria disagreement. Adherence to established
diagnostic guidelines is essential for accurate determination
of mTBI history and for understanding the extent to which mTBI
symptoms resolve or persist over time in OIF/OEF Veterans