139,719 research outputs found
A Bibliometric Study of Authorship and Collaboration Trends Over the Past 30 Years in Four Major Musculoskeletal Science Journals
This study explored changes in bibliometric variables over the last 30 years for four major musculoskeletal science journals (BONE®), Calcified Tissue International® (CTI®), Journal of Bone and Mineral Research® (JBMR®), and Journal of Orthopaedic Research® (JOR®), with a specific focus on author gender. Bibliometric data were collected for all manuscripts in 1985 (BONE®, CTI®, JOR®), 1986 (JBMR®), 1995, 2005, and 2015; 2776 manuscripts met inclusion criteria. Manuscripts from Europe were more often published in BONE® or CTI®, while those from North America in JBMR® or JOR®. All journals demonstrated an increase over time in the number of authors (3.67–7.3), number of countries (1.1–1.4), number of institutions (1.4–3.1), and number of references (25.1–45.4). The number of manuscript pages increased (6.6–8.9) except for JOR® which showed a decline. CTI® had the lowest number of authors (4.9 vs. 5.6–6.8). There was a change in the corresponding author position from first to last for all journals; this change was highest for CTI® (35%) and lowest for BONE® (14.0%). All journals demonstrated an increase over time in female authors; however, CTI® was the highest amongst these four journals. The percentage of female first authors rose from 24.6 to 44.3% (CTI® 29.1–52.3%). The percentage of corresponding female authors rose from 17.5 to 33.6% (CTI® 22.9–40.0%). The proportion of female authors is increasing, likely reflecting the increasing number of women obtaining doctorates in science, medicine, and engineering
Mitigating Charge Transfer Inefficiency in the Chandra X-ray Observatory's ACIS Instrument
The ACIS front-illuminated CCDs onboard the Chandra X-ray Observatory were
damaged in the extreme environment of the Earth's radiation belts, resulting in
enhanced charge transfer inefficiency (CTI). This produces a row dependence in
gain, event grade, and energy resolution. We model the CTI as a function of
input photon energy, including the effects of de-trapping (charge trailing),
shielding within an event (charge in the leading pixels of the 3X3 event island
protect the rest of the island by filling traps), and non-uniform spatial
distribution of traps. This technique cannot fully recover the degraded energy
resolution, but it reduces the position dependence of gain and grade
distributions. By correcting the grade distributions as well as the event
amplitudes, we can improve the instrument's quantum efficiency. We outline our
model for CTI correction and discuss how the corrector can improve
astrophysical results derived from ACIS data.Comment: Accepted by ApJ Letters; see
http://www.astro.psu.edu/users/townsley/cti
An Approach to Catheter Ablation of Cavotricuspid Isthmus Dependent Atrial Flutter
Much of our understanding of the mechanisms of macro re-entrant atrial tachycardia comes from study of cavotricuspid isthmus (CTI) dependent atrial flutter. In the majority of cases, the diagnosis can be made from simple analysis of the surface ECG. Endocardial mapping during tachycardia allows confirmation of the macro re-entrant circuit within the right atrium while, at the same time, permitting curative catheter ablation targeting the critical isthmus of tissue located between the tricuspid annulus and the inferior vena cava. The procedure is short, safe and by demonstration of an electrophysiological endpoint - bidirectional conduction block across the CTI - is associated with an excellent outcome following ablation. It is now fair to say that catheter ablation should be considered as a first line therapy for patients with documented CTI-dependent atrial flutter
Care Transitions: Empowering Older Adults with Post-Hospital Interventions
Educational Objectives
1. Understand how Care Transitions Interventions® (CTI®) can decrease hospital readmission rates among older adults, ages 60 and over.
2. Recognize how CTI® services assist older adults to stay in their homes after hospitalization for 30 days or more without unnecessary readmissions.
3. Appreciate examples of ways Senior Connections, The Capital Area Agency on Aging, collaborates with community partners.
4. Identify how Senior Connections refers older adults and caregivers to community resources for effective utilization and outcomes
Sacrificial charge and the spectral resolution performance of the Chandra Advanced CCD Imaging Spectrometer
Soon after launch, the Advanced CCD Imaging Spectrometer (ACIS), one of the
focal plane instruments on the Chandra X-ray Observatory, suffered radiation
damage from exposure to soft protons during passages through the Earth's
radiation belts. The ACIS team is continuing to study the properties of the
damage with an emphasis on developing techniques to mitigate charge transfer
inefficiency (CTI) and spectral resolution degradation. A post-facto CTI
corrector has been developed which can effectively recover much of the lost
resolution. Any further improvements in performance will require knowledge of
the location and amount of sacrificial charge - charge deposited along the
readout path of an event which fills electron traps and changes CTI. We report
on efforts by the ACIS Instrument team to characterize which charge traps cause
performance degradation and the properties of the sacrificial charge seen
on-orbit. We also report on attempts to correct X-ray pulseheights for the
presence of sacrificial charge.Comment: 9 pages, 7 figures to be published in Proc. SPIE 485
Radiation Hardness Studies in a CCD with High-Speed Column Parallel Readout
Charge Coupled Devices (CCDs) have been successfully used in several high
energy physics experiments over the past two decades. Their high spatial
resolution and thin sensitive layers make them an excellent tool for studying
short-lived particles. The Linear Collider Flavour Identification (LCFI)
collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex
detector of the International Linear Collider (ILC). The CPCCDs can be read out
many times faster than standard CCDs, significantly increasing their operating
speed. The results of detailed simulations of the charge transfer inefficiency
(CTI) of a prototype CPCCD are reported and studies of the influence of gate
voltage on the CTI described. The effects of bulk radiation damage on the CTI
of a CPCCD are studied by simulating the effects of two electron trap levels,
0.17 and 0.44 eV, at different concentrations and operating temperatures. The
dependence of the CTI on different occupancy levels (percentage of hit pixels)
and readout frequencies is also studied. The optimal operating temperature for
the CPCCD, where the effects of the charge trapping are at a minimum, is found
to be about 230 K for the range of readout speeds proposed for the ILC. The
results of the full simulation have been compared with a simple analytic model.Comment: 3 pages, 6 figures; presented at IEEE'07, ALCPG'07, ICATPP'0
Modeling of Charge Transfer Inefficiency in a CCD with High Speed Column Parallel Readout
Charge Coupled Devices (CCDs) have been successfully used in several high
energy physics experiments over the past two decades. Their high spatial
resolution and thin sensitive layers make them an excellent tool for studying
short-lived particles. The Linear Collider Flavour Identification (LCFI)
collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex
detector of a future Linear Collider. The CPCCDs can be read out many times
faster than standard CCDs, significantly increasing their operating speed. An
Analytic Model has been developed for the determination of the charge transfer
inefficiency (CTI) of a CPCCD. The CTI values determined with the Analytic
Model agree largely with those from a full TCAD simulation. The Analytic Model
allows efficient study of the variation of the CTI on parameters like readout
frequency, operating temperature and occupancy.Comment: 5 pages, 13 figures, presented on behalf of the LCFI Collaboration,
proceedings IEEE 2008 Nuclear Science Symposium, Dresden, Germany, and 11th
Topical Seminar on Innovative Particle and Radiation Detectors (IPRD08) 2008,
Siena, Ital
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