1,264 research outputs found
Comparison of Thermal and Microwave Paleointensity Estimates in Specimens Displaying NonâIdeal Behavior in ThellierâStyle Paleointensity Experiments
Determining the strength of the ancient geomagnetic field is vital to our understanding of the core and geodynamo but obtaining reliable measurements of the paleointensity is fraught with difficulties. Over a quarter of magnetic field strength estimates within the global paleointensity database from 0â5 Ma come from HawaiÊ»i. Two previous studies on the SOH1 drill core gave inconsistent, apparently methodâdependent paleointensity estimates, with an average difference of 30%. The paleointensity methods employed in the two studies differed both in demagnetization mechanism (thermal or microwave radiation) and Thellierâstyle protocol (perpendicular and Original Thellier protocols) â both variables that could cause the strong differences in the estimates obtained. Paleointensity experiments have therefore been conducted on 79 specimens using the previously untested combinations of ThermalâPerpendicular and MicrowaveâOriginal Thellier methods to analyze the effects of demagnetization mechanism and protocol in isolation. We find that, individually, neither demagnetization mechanism nor protocol entirely explains the differences in paleointensity estimates. Specifically, we found that nonâideal multiâdomainâlike effects are enhanced using the Original Thellier protocol (independent of demagnetization mechanism), often resulting in paleointensity overestimation. However, we also find evidence, supporting recent findings from the 1960 Kilauea lava flow, that MicrowaveâPerpendicular experiments performed without pTRM checks can produce underestimates of the paleointensity due to unaccountedâfor sample alteration at higher microwave powers. Together, these findings support that the true paleointensities fall between the estimates previously published and emphasize the need for future studies (thermal or microwave) to use protocols with both pTRM checks and a means of detecting nonâideal grain effects
Intrarater and Interrater Reliability of the Soong Classification for Distal Radius Volar Locking Plate Placement
Background: The purpose of this study was to analyze the intrarater and interrater reliability of the Soong classification for volar locking plate placement on a randomly selected, consecutive series of radiographs. Our hypothesis was that the classification would be reliable. Methods: Six physicians of differing levels of training (orthopedic surgery intern to fellowship-trained upper extremity staff) were asked to review 40 radiographs in a random order on 2 separate occasions, 4 weeks apart. All observers graded each image (0, 1, or 2) based on the corresponding Soong grade. A weighted Îș was used to determine the intrarater agreement. The interrater agreement was determined using an intraclass coefficient: Results: The intrarater reliability using a weighted Îș ranged from 0.229 (95% confidence interval [CI]: 0.048-0.411) to 0.946 (95% CI: 0.840-1.051). The interrater intraclass coefficient for Randomization 1 was 0.944 (95% 0.912-0.967) and Randomization 2 was 0.877 (95% CI: 0.797-0.930). Conclusion: The Soong classification is a reliable tool, both interrater and intrarater, for assessing distal radius volar locking plate placement. The classification system remained reliable despite a randomly selected, consecutive series of images and physician observers of varying levels of training
Using Multiple-hierarchy Stratification and Life Course Approaches to Understand Health Inequalities: The Intersecting Consequences of Race, Gender, SES, and Age
This study examines how the intersecting consequences of race-ethnicity, gender, socioeconomics status (SES), and age influence health inequality. We draw on multiple-hierarchy stratification and life course perspectives to address two main research questions. First, does racial-ethnic stratification of health vary by gender and/or SES? More specifically, are the joint health consequences of racial-ethnic, gender, and socioeconomic stratification additive or multiplicative? Second, does this combined inequality in health decrease, remain stable, or increase between middle and late life? We use panel data from the Health and Retirement Study (N = 12,976) to investigate between- and within-group differences in in self-rated health among whites, blacks, and Mexican Americans. Findings indicate that the effects of racial-ethnic, gender, and SES stratification are interactive, resulting in the greatest racial-ethnic inequalities in health among women and those with higher levels of SES. Furthermore, racial-ethnic/gender/SES inequalities in health tend to decline with age. These results are broadly consistent with intersectionality and aging-as-leveler hypotheses
Changes in Cardiovascular Health in the United States, 2003â2011
Background
Cardiovascular disease is the leading cause of death in the United States, making improving cardiovascular health a key population health goal. As part of efforts to achieve this, the American Heart Association has developed the first comprehensive cardiovascular health index (CVHI). Our objective was to investigate the changes in CVHI in US states from 2003 to 2011. Methods and Results
CVHI was examined using Behavioral Risk Factor Surveillance System data between 2003 and 2011 (oddânumbered years). Total CVHI decreased from 3.73±0.01 in 2003 to 3.65±0.01 in 2009. The majority of states (88%) experienced a decline in CVHI and an increase in the prevalence of âpoorâ CVHI between 2003 and 2009. Among CVHI components, the highest prevalence of âidealâ was observed for blood glucose followed by smoking, whereas the lowest prevalence of âidealâ was observed for physical activity and diet. Between 2003 and 2009, prevalence of âidealâ smoking and diet status increased, while âidealâ prevalence of blood pressure, cholesterol, blood glucose, body mass index, and physical activity status decreased. We observed statistically significant differences between 2009 and 2011, outside the scope of the 2003â2009 trend, which we hypothesize are partially attributable to differences in sample demographic characteristics related to changes in Behavioral Risk Factor Surveillance System methodology. Conclusions
Overall, CVHI decreased, most likely due to decreases in âidealâ blood pressure, body mass index, and cholesterol status, which may stem from low prevalence of âidealâ physical activity and diet status. These findings can be used to inform stateâspecific strategies and targets to improve cardiovascular health
Semiclassical quantization with bifurcating orbits
Bifurcations of classical orbits introduce divergences into semiclassical
spectra which have to be smoothed with the help of uniform approximations. We
develop a technique to extract individual energy levels from semiclassical
spectra involving uniform approximations. As a prototype example, the method is
shown to yield excellent results for photo-absorption spectra for the hydrogen
atom in an electric field in a spectral range where the abundance of
bifurcations would render the standard closed-orbit formula without uniform
approximations useless. Our method immediately applies to semiclassical trace
formulae as well as closed-orbit theory and offers a general technique for the
semiclassical quantization of arbitrary systems
The LARP1 La-Module recognizes both ends of TOP mRNAs
La-Related Protein 1 (LARP1) is an RNA-binding protein that regulates the stability and translation of mRNAs encoding the translation machinery, including ribosomal proteins and translation factors. These mRNAs are characterized by a 5Êč-terminal oligopyrimidine (TOP) motif that coordinates their temporal and stoichiometric expression. While LARP1 represses TOP mRNA translation via the C-terminal DM15 region, the role of the N-terminal La-Module in the recognition and translational regulation of TOP mRNAs remains elusive. Herein we show that the LARP1 La-Module also binds TOP motifs, although in a cap-independent manner. We also demonstrate that it recognizes poly(A) RNA. Further, our data reveal that the LARP1 La-Module can simultaneously engage TOP motifs and poly(A) RNA. These results evoke an intriguing molecular mechanism whereby LARP1 could regulate translation and stabilization of TOP transcripts
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Osteocyte dysfunction promotes osteoarthritis through MMP13-dependent suppression of subchondral bone homeostasis.
Osteoarthritis (OA), long considered a primary disorder of articular cartilage, is commonly associated with subchondral bone sclerosis. However, the cellular mechanisms responsible for changes to subchondral bone in OA, and the extent to which these changes are drivers of or a secondary reaction to cartilage degeneration, remain unclear. In knee joints from human patients with end-stage OA, we found evidence of profound defects in osteocyte function. Suppression of osteocyte perilacunar/canalicular remodeling (PLR) was most severe in the medial compartment of OA subchondral bone, with lower protease expression, diminished canalicular networks, and disorganized and hypermineralized extracellular matrix. As a step toward evaluating the causality of PLR suppression in OA, we ablated the PLR enzyme MMP13 in osteocytes while leaving chondrocytic MMP13 intact, using Cre recombinase driven by the 9.6-kb DMP1 promoter. Not only did osteocytic MMP13 deficiency suppress PLR in cortical and subchondral bone, but it also compromised cartilage. Even in the absence of injury, osteocytic MMP13 deficiency was sufficient to reduce cartilage proteoglycan content, change chondrocyte production of collagen II, aggrecan, and MMP13, and increase the incidence of cartilage lesions, consistent with early OA. Thus, in humans and mice, defects in PLR coincide with cartilage defects. Osteocyte-derived MMP13 emerges as a critical regulator of cartilage homeostasis, likely via its effects on PLR. Together, these findings implicate osteocytes in bone-cartilage crosstalk in the joint and suggest a causal role for suppressed perilacunar/canalicular remodeling in osteoarthritis
Does the use of store-and-forward telehealth systems improve outcomes for clinicians managing diabetic foot ulcers? A pilot study
Diabetic foot ulcers are one of the most hospitalised diabetes complications and contribute to many leg amputations.\ud
Trained diabetic foot teams and specialists managing diabetic foot ulcers have demonstrated reductions in amputations and hospitalisation by up to 90%. Few such teams exist in Australia. Thus, access is limited for all geographical populations and may somewhat explain the high rates of hospitalisation.\ud
Aim: This pilot study aims to analyse if local clinicians managing diabetic foot complications report improved access to diabetic foot specialists and outcomes with the introduction of a telehealth store-and-forward system.\ud
Method: A store-and-forward telehealth system was implemented in six different Queensland locations between August 2009 and February 2010. Sites were offered ad hoc and/or fortnightly telehealth access to a diabetic foot speciality service. A survey was sent six months following commencement of the trial to the 14 eligible clinicians involved in the trial to gauge clinical perception of the telehealth system.\ud
Results: Eight participants returned the surveys. The majority of responding clinicians reported that the telehealth system was easy to use (100%), improved their access to diabetic foot speciality services (75%), improved upskilling of local diabetes service staff (100%), and improved patient outcomes (100%).\ud
Conclusion: This pilot study suggests that clinicians found the use of a telehealth store-and-forward system very useful in improving access to speciality services, clinical skills and patient outcomes. This study supports the recommendation that telehealth systems should be made available for diabetic foot ulcer management
60 Validated Planets from K2 Campaigns 5-8
We present a uniform analysis of 155 candidates from the second year of
NASA's mission (Campaigns 5-8), yielding 60 statistically validated
planets spanning a range of properties, with median values of = 2.5
, = 7.1 d, = 811 K, and = 11.3 mag. The
sample includes 24 planets in 11 multi-planetary systems, as well as 18 false
positives, and 77 remaining planet candidates. Of particular interest are 18
planets smaller than 2 , five orbiting stars brighter than = 10
mag, and a system of four small planets orbiting the solar-type star EPIC
212157262. We compute planetary transit parameters and false positive
probabilities using a robust statistical framework and present a complete
analysis incorporating the results of an intensive campaign of high resolution
imaging and spectroscopic observations. This work brings the yield to over
360 planets, and by extrapolation we expect that will have discovered
600 planets before the expected depletion of its on-board fuel in late
2018.Comment: 33 pages, 13 figures, 5 tables, accepted for publication in A
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