Age-related changes in neural circuits, neural networks, and their plasticity are central to our understanding of age changes in cognition and brain structure and function. This paper summarizes ...selected findings on these topics presented at the Cognitive Aging Summit II. Specific areas discussed were synaptic vulnerability and plasticity, including the role of different types of synaptic spines, and hormonal effects in the dorsolateral prefrontal cortex of nonhuman primates, the impact of both compensatory processes and dedifferentiation on demand-dependent differences in prefrontal activation in relation to age and performance, the role of vascular disease, indexed by white matter signal abnormalities, on prefrontal activation during a functional magnetic resonance imaging-based cognitive control paradigm, and the influence of amyloid-β neuropathology on memory performance in older adults and the networks of brain activity underlying variability in performance. A greater understanding of age-related changes in brain plasticity and neural networks in healthy aging and in the presence of underlying vascular disease or amyloid pathology will be essential to identify new targets for intervention. Moreover, this understanding will assist in promoting the utilization of existing interventions, such as lifestyle and therapeutic modifiers of vascular disease.
This study examines issues in the measurement of HIV risk factors, using daily diaries to collect data on both alcohol use and sexual behavior. Seventy-nine adolescents and young adults recruited ...from an STD clinic and from a university campus were studied. Participants gave daily reports of their drinking, drug use, and sexual activities for 4 weeks. Respondents then completed a retrospective questionnaire asking about the frequencies of these behaviors during the preceding period. Diary reports of behavior were strongly correlated with retrospective reports. More frequent drinking was reported on the diary measure than the retrospective measure, and this discrepancy was larger for more frequent drinkers. Frequency of sexual activity was overreported on the retrospective measure only among adolescents. Errors in the measurement of alcohol use, sexual behavior, or their co-occurrence could affect estimations of the relationship of alcohol use to sexual behavior. The types of error inherent in these measures may differ, resulting in different tendencies toward over- or underreporting of alcohol use and sexual behavior, depending on frequency of the behavior and the characteristics of the subject population.
Urban geometry and materials combine to create complex spatial, temporal and directional patterns of longwave infrared (LWIR) radiation. Effective anisotropy (or directional variability) of thermal ...radiance causes remote sensing (RS) derived urban surface temperatures to vary with RS view angles. Here a new and novel method to resolve effective thermal anisotropy processes from LWIR camera observations is demonstrated at the Comprehensive Outdoor Scale MOdel (COSMO) test site. Pixel-level differences of brightness temperatures reach 18.4 K within one hour of a 24-h study period. To understand this variability, the orientation and shadowing of surfaces is explored using the Discrete Anisotropic Radiative Transfer (DART) model and Blender three-dimensional (3D) rendering software. Observed pixels and the entire canopy surface are classified in terms of surface orientation and illumination. To assess the variability of exitant longwave radiation (MLW) from the 3D COSMO surface (MLW3D), the observations are prescribed based on class. The parameterisation is tested by simulating thermal images using a camera view model to determine camera perspectives of MLW3D fluxes. The mean brightness temperature differences per image (simulated and observed) are within 0.65 K throughout a 24-h period. Pixel-level comparisons are possible with the high spatial resolution of MLW3D and DART camera view simulations. At this spatial scale (<0.10 m), shadow hysteresis, surface sky view factor and building edge effects are not completely resolved by MLW3D. By simulating apparent brightness temperatures from multiple view directions, effective thermal anisotropy of MLW3D is shown to be up to 6.18 K. The developed methods can be extended to resolve some of the identified sources of sub-facet variability in realistic urban settings. The extension of DART to the interpretation of ground-based RS is shown to be promising.
•Diurnal longwave infrared radiation observations of the COSMO urban canopy•Method for per-pixel dynamic classification of observations•Brightness temperature for all surfaces at high spatial and temporal resolution•Explanation of observed variability based on surface orientation and shading•Brightness temperatures used to model urban thermal anisotropy
The GUVI on board the NASA's TIMED satellite provides a new capability for monitoring equatorial electron density irregularities. The nighttime GUVI disk scan images of OI 135.6‐nm show numerous ...emission‐depleted dark features in the equatorial region. The dark features show typical equatorial bubble characteristics ‐ elongation in the north‐south direction, westward tilt, and season‐longitudinal variations in their distribution. Coincident in‐situ observations by ROCSAT‐1 satellite identify plasma depletions co‐located with the emission depletions. The individual bubble images are hardly distinguishable in the equatorial region owing to an occurrence of multiple bubbles and owing to the low background radiance at the ionization trough. Occasionally, a reversed “C”‐shaped bubble images appear on the GUVI swath of a single orbit. Those global bubble images corroborate the occurrence of plasma depletion in the whole magnetic flux tube and the presence of vertical shear of zonal bulk plasma flow in the topside ionosphere.
Impact of personalized report cards on nurses managing central lines Morrison, Theresa, PhD, CNS-BC; Raffaele, Jacqueline, DNP, RN; Brennaman, Laura, PhD, RN
American journal of infection control,
2017, 2017-01-01, 2017-01-00, 20170101, Letnik:
45, Številka:
1
Journal Article
Recenzirano
Highlights • Visual audits of central line dressings and intravenous tubing captured less than half (n = 291) of central line–associated bloodstream infection contributing factors. • Documentation ...audits of the lines that failed the visual audit captured an additional 54% (n = 337) of central line–associated bloodstream infection contributing factors. • Significant association between personalized nurse report card use and decrease in central line–associated bloodstream infection contributing factor frequency. • Unit case reports, which detailed both visual and documentation audit contributing factors and nurses' assigned to patients whose line failed the audits, are used to create the report cards and assist the manager is identifying patterns.
Mechanical testing of cadaveric lumbar motion segments.
To test the hypothesis that minor damage to a vertebral body can lead to progressive disruption of the adjacent intervertebral disc.
Disc ...degeneration involves gross structural disruption as well as cell-mediated changes in matrix composition, but there is little evidence concerning which comes first. Comparatively minor damage to a vertebral body is known to decompress the adjacent discs, and this may adversely affect both structure and cell function in the disc.
In this study, 38 cadaveric lumbar motion segments (mean age, 51 years) were subjected to complex mechanical loading to simulate typical activities in vivo while the distribution of compressive stress in the disc matrix was measured using a pressure transducer mounted in a needle 1.3 mm in diameter. "Stress profiles" were repeated after a controlled compressive overload injury had reduced motion segment height by approximately 1%. Moderate repetitive loading, appropriate for the simulation of light manual labor, then was applied to the damaged specimens for approximately 4 hours, and stress profilometry was repeated a third time. Discs then were sectioned and photographed.
Endplate damage reduced pressure in the adjacent nucleus pulposus by 25% +/- 27% and generated peaks of compressive stress in the anulus, usually posteriorly to the nucleus. Discs 50 to 70 years of age were affected the most. Repetitive loading further decompressed the nucleus and intensified stress concentrations in the anulus, especially in simulated lordotic postures. Sagittal plane sections of 15 of the discs showed an inwardly collapsing anulus in 9 discs, extreme outward bulging of the anulus in 11 discs, and complete radial fissures in 2 discs, 1 of which allowed posterior migration of nucleus pulposus. Comparisons with the results from tissue culture experiments indicated that the observed changes in matrix compressive stress would inhibit disc cell metabolism throughout the disc, and could lead to progressive deterioration of the matrix.
Minor damage to a vertebral body endplate leads to progressive structural changes in the adjacent intervertebral discs.
Health surveillance is the ongoing, systematic
use of routinely collected health
data to guide public health action in a
timely fashion.
This paper describes the creation and
growth of national ...surveillance systems
in Canada and their impact on chronic
disease and injury prevention.
In 2008, the authors started a review process
to retrace the history of the early development
of national chronic disease surveillance
in Canada from 1960 to 2000. A 1967
publication describes the history of the
development of the Laboratory of Hygiene
from 1921 to 1967. This review is a sequel
to that paper and describes the history of the
development of national chronic disease
surveillance in Canada before and after the
formation of the Laboratory Centre for
Disease Control (LCDC).
First Images of Asteroid 243 Ida Belton, M. J. S.; Chapman, C. R.; Veverka, J. ...
Science (American Association for the Advancement of Science),
09/1994, Letnik:
265, Številka:
5178
Journal Article
Recenzirano
The first images of the asteroid 243 Ida from Galileo show an irregular object measuring 56 kilometers by 24 kilometers by 21 kilometers. Its surface is rich in geologic features, including systems ...of grooves, blocks, chutes, albedo features, crater chains, and a full range of crater morphologies. The largest blocks may be distributed nonuniformly across the surface; lineaments and dark-floored craters also have preferential locations. Ida is interpreted to have a substantial regolith. The high crater density and size-frequency distribution (-3 differential power-law index) indicate a surface in equilibrium with saturated cratering. A minimum model crater age for Ida-and therefore for the Koronis family to which Ida belongs-is estimated at 1 billion years, older than expected.
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