1,095 research outputs found
Construction and Calibration of a Streaked Optical Spectrometer for Shock Temperature
Here we describe the implementation and calibration of a streaked visible
spectrometer (SVS) for optical pyrometry and emission/absorption spectroscopy
on light gas gun platforms in the UC Davis Shock Compression Laboratory. The
diagnostic consists of an optical streak camera coupled to a spectrometer to
provide temporally and spectrally-resolved records of visible emission from
dynamically-compressed materials. Fiber optic coupling to the sample enables a
small diagnostic footprint on the target face and flexibility of operation on
multiple launch systems without the need for open optics. We present the
details of calibration (time, wavelength and spectral radiance) for absolute
temperature determination and present benchmark measurements of system
performance.Comment: 6 pages, 3 figures Davies, E., et al. (accepted). In J. Lane, T.
Germann, and M. Armstrong (Eds.), 21st Biennial APS Conference on Shock
Compression of Condensed Matter (SCCM19). AIP Publishin
A Phenomenology of the Job-Related Experiences of Early Career Catholic Elementary School Principals
This qualitative phenomenology investigated the job-related experiences of early career Catholic elementary school principals (N = 13) in the Mideastern region of the United States. Data were collected from an introductory survey, semi-structured interviews, two focus groups, and a participant designed plan for professional development. The findings indicated that Catholic elementary principals in their early career are motivated by a calling to a vocation in Catholic school leadership as well as the ability to develop and implement a vision for their school. Principals reported being challenged by limited resources, balancing the demands of the position, and navigating relationships. Finally, principals believed they are supported by diocesan administrators in the areas of human resources and student issues, particularly if the concerns have legal implications
Upper Extremity Motor Learning among Individuals with Parkinson's Disease: A Meta-Analysis Evaluating Movement Time in Simple Tasks
Motor learning has been found to occur in the rehabilitation of individuals with Parkinson's disease (PD). Through repetitive structured practice of motor tasks, individuals show improved performance, confirming that motor learning has probably taken place. Although a number of studies have been completed evaluating motor learning in people with PD, the sample sizes were small and the improvements were variable. The purpose of this meta-analysis was to determine the ability of people with PD to learn motor tasks. Studies which measured movement time in upper extremity reaching tasks and met the inclusion criteria were included in the analysis. Results of the meta-analysis indicated that people with PD and neurologically healthy controls both demonstrated motor learning, characterized by a decrease in movement time during upper extremity movements. Movement time improvements were greater in the control group than in individuals with PD. These results support the findings that the practice of upper extremity reaching tasks is beneficial in reducing movement time in persons with PD and has important implications for rehabilitation
Children with ADD/ADHD: Survey results provide insights into effective optometric vision management of this special population
Optometric management of ADDI/DHD children is being done in both the primary vision care practice as well as the vision therapy and pediatric care practice. This is a special population which may pose unique examination or treatment challenges to the general practitioner. The role of the optometrist in the vision care of ADD/ADHD children is explored through an e-mail survey sent via the internet. The survey emphasized the elicitation of clinical pearls from optometrists currently working with this special population regarding their views and experiences on successful examination and management of the ADD/ADHD patient. Certain challenges presented by the process of medical diagnoses and pharmacological treatment of ADD/ADHD is explored. The goal is to enlighten the general practitioner about some of the issues surrounding this often misunderstood condition and provide a collection of clinical advice and optometric viewpoints which will assist the general practitioner in his or her optometric care of this population
Sirolimus-eluting versus uncoated stents in acute myocardial infarction.
BACKGROUND: Sirolimus-eluting stents reduce rates of restenosis and reintervention, as compared with uncoated stents. Data are limited regarding the safety and efficacy of such stents in primary percutaneous coronary intervention (PCI) for acute myocardial infarction with ST-segment elevation. METHODS: We performed a single-blind, multicenter, prospectively randomized trial to compare sirolimus-eluting stents with uncoated stents in primary PCI for acute myocardial infarction with ST-segment elevation. The trial included 712 patients at 48 medical centers. The primary end point was target-vessel failure at 1 year after the procedure, defined as target-vessel-related death, recurrent myocardial infarction, or target-vessel revascularization. A follow-up angiographic substudy was performed at 8 months among 174 patients from selected centers. RESULTS: The rate of the primary end point was significantly lower in the sirolimus-stent group than in the uncoated-stent group (7.3% vs. 14.3%, P=0.004). This reduction was driven by a decrease in the rate of target-vessel revascularization (5.6% and 13.4%, respectively; P<0.001). There was no significant difference between the two groups in the rate of death (2.3% and 2.2%, respectively; P=1.00), reinfarction (1.1% and 1.4%, respectively; P=1.00), or stent thrombosis (3.4% and 3.6%, respectively; P=1.00). The degree of neointimal proliferation, as assessed by the mean (+/-SD) in-stent late luminal loss, was significantly lower in the sirolimus-stent group (0.14+/-0.49 mm, vs. 0.83+/-0.52 mm in the uncoated stent group; P<0.001). CONCLUSIONS: Among selected patients with acute myocardial infarction, the use of sirolimus-eluting stents significantly reduced the rate of target-vessel revascularization at 1 year. (ClinicalTrials.gov number, NCT00232830 [ClinicalTrials.gov].)
Factors that Influence Teachersā Views on Standardized Tests
The central aim of this study was to explore K-12 teachersā (N = 183) attitudes about standardized tests as a function of experience, instructional level, student population, and type of school. The Teachersā Views on Standardized Tests Questionnaire was developed to assess teachersā perceptions of the impact of standardized tests on practice. All survey items were intended to measure a facet of teachersā attitudes regarding the necessity of standardized tests and their influence on best practices. Findings from this study indicated that special education and inclusion teachers viewed standardized tests as more negatively influencing instruction than general education teachers. There were also significant differences by instructional level and type of school (i.e., public vs. independent). Compared to elementary teachers, middle and high school teachersā views were more negative, and public school educators perceived standardized assessments as having a more negative influence on instruction than teachers in independent schools. Finally, elementary school teachers reported that the standards of learning were more appropriate in contrast to middle and high school teachers
Associations of Medicaid Expansion with Insurance Coverage, Stage at Diagnosis, and Treatment among Patients with Genitourinary Malignant Neoplasms
Importance: Health insurance coverage is associated with improved outcomes in patients with cancer. However, it is unknown whether Medicaid expansion through the Patient Protection and Affordable Care Act (ACA) was associated with improvements in the diagnosis and treatment of patients with genitourinary cancer. Objective: To assess the association of Medicaid expansion with health insurance status, stage at diagnosis, and receipt of treatment among nonelderly patients with newly diagnosed kidney, bladder, or prostate cancer. Design, Setting, and Participants: This case-control study included adults aged 18 to 64 years with a new primary diagnosis of kidney, bladder, or prostate cancer, selected from the National Cancer Database from January 1, 2011, to December 31, 2016. Patients in states that expanded Medicaid were the case group, and patients in nonexpansion states were the control group. Data were analyzed from January 2020 to March 2021. Exposures: State Medicaid expansion status. Main Outcomes and Measures: Insurance status, stage at diagnosis, and receipt of cancer and stage-specific treatments. Cases and controls were compared with difference-in-difference analyses. Results: Among a total of 340552 patients with newly diagnosed genitourinary cancers, 94033 (27.6%) had kidney cancer, 25770 (7.6%) had bladder cancer, and 220749 (64.8%) had prostate cancer. Medicaid expansion was associated with a net decrease in uninsured rate of 1.1 (95% CI, -1.4 to -0.8) percentage points across all incomes and a net decrease in the low-income population of 4.4 (95% CI, -5.7 to -3.0) percentage points compared with nonexpansion states. Expansion was also associated with a significant shift toward early-stage diagnosis in kidney cancer across all income levels (difference-in-difference, 1.4 [95% CI, 0.1 to 2.6] percentage points) and among individuals with low income (difference-in-difference, 4.6 [95% CI, 0.3 to 9.0] percentage points) and in prostate cancer among individuals with low income (difference-in-difference, 3.0 [95% CI, 0.3 to 5.7] percentage points). Additionally, there was a net increase associated with expansion compared with nonexpansion in receipt of active surveillance for low-risk prostate cancer of 4.1 (95% CI, 2.9 to 5.3) percentage points across incomes and 4.5 (95% CI, 0 to 9.0) percentage points among patients in low-income areas. Conclusions and Relevance: These findings suggest that Medicaid expansion was associated with decreases in uninsured status, increases in the proportion of kidney and prostate cancer diagnosed in an early stage, and higher rates of active surveillance in the appropriate, low-risk prostate cancer population. Associations were concentrated in population residing in low-income areas and reinforce the importance of improving access to care to all patients with cancer
Epidemiology of Staphylococcus aureus infections in patients admitted to freestanding pediatric hospitals, 2009-2016
HIV/AIDS among Inmates of and Releasees from US Correctional Facilities, 2006: Declining Share of Epidemic but Persistent Public Health Opportunity
Because certain groups at high risk for HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome) come together in correctional facilities, seroprevalence was high early in the epidemic. The share of the HIV/AIDS epidemic borne by inmates of and persons released from jails and prisons in the United States (US) in 1997 was estimated in a previous paper. While the number of inmates and releasees has risen, their HIV seroprevalence rates have fallen. We sought to determine if the share of HIV/AIDS borne by inmates and releasees in the US decreased between 1997 and 2006. We created a new model of population flow in and out of correctional facilities to estimate the number of persons released in 1997 and 2006. In 1997, approximately one in five of all HIV-infected Americans was among the 7.3 million who left a correctional facility that year. Nine years later, only one in seven (14%) of infected Americans was among the 9.1 million leaving, a 29.3% decline in the share. For black and Hispanic males, two demographic groups with heightened incarceration rates, recently released inmates comprise roughly one in five of those groups' total HIV-infected persons, a figure similar to the proportion borne by the correctional population as a whole in 1997. Decreasing HIV seroprevalence among those admitted to jails and prisons, prolonged survival and aging of the US population with HIV/AIDS beyond the crime-prone years, and success with discharge planning programs targeting HIV-infected prisoners could explain the declining concentration of the epidemic among correctional populations. Meanwhile, the number of persons with HIV/AIDS leaving correctional facilities remains virtually identical. Jails and prisons continue to be potent targets for public health interventions. The fluid nature of incarcerated populations ensures that effective interventions will be felt not only in correctional facilities but also in communities to which releasees return
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