1,137 research outputs found
TriG - A GNSS Precise Orbit and Radio Occultation Space Receiver
The GPS radio occultation (RO) technique [1] produces
measurements in the ionosphere and neutral atmosphere
[2] that contribute to monitoring space weather and climate
change; and improving operational weather prediction.
The high accuracy of RO soundings, traceable to SI standards,
makes them ideal climate benchmark observations. For
weather applications, RO observations improve the accuracy
of weather forecasts by providing temperature and moisture
profiles of sub-km vertical resolution, over land and ocean
and in the presence of clouds.
JPL is currently flying a handful of RO instruments [3] on
various satellites in Low Earth Orbit (LEO). Although these
receivers have served to pioneer occultation measurements,
various advances in technology and understanding of the RO
technique along with availability of new signals from GPS and
other GNSS satellites allow us to design an improved next
generation space-based Precise Orbit Determination (POD)
and RO receiver, the TriG receiver. The paper describes the
architecture and implementation of the JPL TriG receiver as
well as results obtained with a prototype receiver demonstrating
key technologies necessary for a next-generation space
science receiver
The Effects of Two Planning Interventions on the Oral Health Behavior of Iranian Adolescents: A Cluster Randomized Controlled Trial.
PURPOSE: The aim of this study was to investigate the effectiveness of a planning intervention (specifying when, where, and how to act) and an implementation intention intervention (specifying the same in the format of an if-then plan) in increasing self-reported brushing in adolescents.
METHODS: The study adopted a cluster randomized controlled trial design, and 1158 students in 48 schools were randomized to planning, implementation intention, or active control conditions. After baseline assessment, all participants received a leaflet containing information and recommendations on oral health and instructions on correct brushing behavior. After reading the leaflets, they were provided with a toothbrush and toothpaste plus a calendar in which to record their brushing. Participants in the planning condition and in the implementation intention condition also received instructions to form specific plans regarding brushing behavior. Self-reported brushing, perceived behavioral control, self-monitoring, intention, frequency of planning, oral health-related quality of life, and dental plaque and periodontal status were measured 1 and 6 months later.
RESULTS: Both intervention conditions showed a significant improvement in the frequency of self-reported brushing, self-monitoring, frequency of planning, intention, perceived behavioral control, plaque index, periodontal health, and oral health-related quality of life compared to the control condition at both follow-ups. Comparing the two intervention conditions revealed that adolescents who received the implementation intention intervention had significantly greater improvement in the frequency of self-reported brushing, intention, frequency of planning, and periodontal health than those in planning condition.
CONCLUSIONS: Taken together, the findings suggest that forming implementation intentions as well as planning has the potential to increase dental self-reported brushing rates in adolescents, but that forming implementation intentions has the strongest impact on dental hygiene behavior and is, therefore, recommended.
TRIAL REGISTRATION NUMBER: The trial was registered with the ClinicalTrials.gov database (NCT02066987) https://www.clinicaltrials.gov/ct2/show/NCT02066987
Swimming with captive dolphins: current debates and post-experience dissonance
Dolphins have widespread contemporary appeal and anthropomorphic social representations of dolphins have fuelled a growing desire in tourist populations to seek interaction with them. This paper is concerned with the staged performance of swim-with-dolphin interaction programmes in aquaria. Qualitative interviews with tourists who have swum with captive dolphins identified their immediate recollections and stressed the grace, size and power of dolphins, but also a belief that the experience was too staged, too short and too expensive. Post-purchase dissonance focused on concerns with the size of enclosures and about captivity, too many tricks, limited interpretation and unfulfilled expectations of a quality interaction
Effects of lanreotide Autogel primary therapy on symptoms and quality-of-life in acromegaly : data from the PRIMARYS study
To evaluate the effects of lanreotide Autogel on patient-reported outcomes and association with biochemical control, using PRIMARYS data. PRIMARYS was a 1-year, open-label study of lanreotide Autogel (Depot in USA) 120 mg every 4 weeks in 90 treatment-naïve patients with acromegaly. Symptoms were assessed using Patient-assessed Acromegaly Symptom Questionnaire (PASQ) and health-related quality of life (HRQoL) using the AcroQoL questionnaire. Correlations between PASQ and AcroQoL scores, and between PASQ/AcroQoL and growth hormone (GH)/insulin-like growth factor-1 (IGF-1) levels were also evaluated (post hoc). Acromegaly symptoms and HRQoL significantly improved from week 12 to week 48, with modest correlations at week 48 between PASQ total score (R = -0.55, p 50 % of baseline standard deviation) in PASQ total score and >40 % achieved a MID in AcroQoL global score (post hoc). Changes in PASQ scores were similar in biochemically controlled (GH levels ≤2.5 μg/L and normal IGF-1 levels) and uncontrolled groups, while changes in global and psychological AcroQoL scores were greater in the controlled group. There was no correlation between changes in PASQ or AcroQoL scores and changes in GH or IGF-1 levels. Primary treatment with lanreotide Autogel over 1 year was associated with rapid and sustained improvements in clinical signs and symptoms and HRQoL in patients with acromegaly. Improvements in HRQoL, but not symptoms, were greater in those achieving biochemical control (ClinicalTrials.gov: NCT00690898; EudraCT: 2007-000155-34). The online version of this article (doi:10.1007/s11102-015-0693-y) contains supplementary material, which is available to authorized users
Liver Function Test Abnormalities in Experimental and Clinical Plasmodium vivax Infection
Liver transaminase elevations after treatment in malaria volunteer infection studies (VISs) have raised safety concerns. We investigated transaminase elevations from two human Plasmodium vivax VISs where subjects were treated with chloroquine (n = 24) or artefenomel (n = 8) and compared them with studies in Thailand (n = 41) and Malaysia (n = 76). In the VISs, alanine transaminase (ALT) increased to ≥ 2.5 × upper limit of normal (ULN) in 11/32 (34%) volunteers, peaking 5–8 days posttreatment. Transaminase elevations were asymptomatic, were not associated with elevated bilirubin, and resolved by day 42. The risk of an ALT ≥ 2.5 × ULN increased more than 4-fold (odds ratio [OR] 4.28; 95% CI: 1.26–14.59; P = 0.02) for every log10 increase in the parasite clearance burden (PCB), defined as the log-fold reduction in parasitemia 24 hours post-treatment. Although an elevated ALT ≥ 2.5 × ULN was more common after artefenomel than after chloroquine (5/8 [63%] versus 6/24 [25%]; OR 5.0; 95% CI: 0.91–27.47; P = 0.06), this risk disappeared when corrected for parasite clearance burden (PCB). Peak ALT also correlated with peak C-reactive protein (R = 0.44; P = 0.012). Elevations in ALT (≥ 2.5 × ULN) were less common in malaria-endemic settings, occurring in 1/41 (2.5%) Thai patients treated with artefenomel, and in none of 76 Malaysians treated with chloroquine or artemisinin combination therapy. Post-treatment transaminase elevations are common in experimental P. vivax infection but do not appear to impact on participant safety. Although the mechanism of these changes remains uncertain, host inflammatory response to parasite clearance may be contributory
Analysis of complete mitochondrial genomes from extinct and extant rhinoceroses reveals lack of phylogenetic resolution
<p>Abstract</p> <p>Background</p> <p>The scientific literature contains many examples where DNA sequence analyses have been used to provide definitive answers to phylogenetic problems that traditional (non-DNA based) approaches alone have failed to resolve. One notable example concerns the rhinoceroses, a group for which several contradictory phylogenies were proposed on the basis of morphology, then apparently resolved using mitochondrial DNA fragments.</p> <p>Results</p> <p>In this study we report the first complete mitochondrial genome sequences of the extinct ice-age woolly rhinoceros (<it>Coelodonta antiquitatis</it>), and the threatened Javan (<it>Rhinoceros sondaicus</it>), Sumatran (<it>Dicerorhinus sumatrensis</it>), and black (<it>Diceros bicornis</it>) rhinoceroses. In combination with the previously published mitochondrial genomes of the white (<it>Ceratotherium simum</it>) and Indian (<it>Rhinoceros unicornis</it>) rhinoceroses, this data set putatively enables reconstruction of the rhinoceros phylogeny. While the six species cluster into three strongly supported sister-pairings: (i) The black/white, (ii) the woolly/Sumatran, and (iii) the Javan/Indian, resolution of the higher-level relationships has no statistical support. The phylogenetic signal from individual genes is highly diffuse, with mixed topological support from different genes. Furthermore, the choice of outgroup (horse <it>vs </it>tapir) has considerable effect on reconstruction of the phylogeny. The lack of resolution is suggestive of a hard polytomy at the base of crown-group Rhinocerotidae, and this is supported by an investigation of the relative branch lengths.</p> <p>Conclusion</p> <p>Satisfactory resolution of the rhinoceros phylogeny may not be achievable without additional analyses of substantial amounts of nuclear DNA. This study provides a compelling demonstration that, in spite of substantial sequence length, there are significant limitations with single-locus phylogenetics. We expect further examples of this to appear as next-generation, large-scale sequencing of complete mitochondrial genomes becomes commonplace in evolutionary studies.</p> <p><it>"The human factor in classification is nowhere more evident than in dealing with this superfamily (Rhinocerotoidea)." G. G. Simpson (1945)</it></p
The Influence of Surface Roughness on Nucleate Pool Boiling Heat Transfer
The effect of surface roughness on pool boiling heat transfer is experimentally explored over a wide range of roughness values in water and Fluorinert™ FC-77, two fluids with different thermal properties and wetting characteristics. The test surfaces ranged from a polished surface (Ra between 0.027 micrometer and 0.038 micrometer) to electrical discharge machined (EDM) surfaces with a roughness Ra ranging from 1.08 micrometer to 10.0 micrometer. Different trends were observed in the heat transfer coefficient with respect to the surface roughness between the two fluids on the same set of surfaces. For FC-77, the heat transfer coefficient was found to continually increase with increasing roughness. For water, on the other hand, EDM surfaces of intermediate roughness displayed similar heat transfer coefficients that were higher than for the polished surface, while the roughest surface showed the highest heat transfer coefficients. The heat transfer coefficients were more strongly influenced by surface roughness with FC-77 than with water. For FC-77, the roughest surface produced 210% higher heat transfer coefficients than the polished surface while for water, a more modest 100% enhancement was measured between the same set of surfaces. Although the results highlight the inadequacy of characterizing nucleate pool boiling data using Ra, the observed effect of roughness was correlated using hRa m as has been done in several prior studies. The experimental results were compared with predictions from several widely used correlations in the literature
Aortic Annulus Diameter Determination by Multidetector Computed Tomography Reproducibility, Applicability, and Implications for Transcatheter Aortic Valve Implantation
ObjectivesThis study sought to determine the most reproducible multidetector computed tomography (MDCT) measurements of the aortic annulus and to determine methods to improve the applicability of these measurements for transcatheter aortic valve implantation.BackgroundThe reproducibility and applicability of MDCT annular measurements to guide transcatheter aortic valve implantation remain unclear.MethodsAnnular measurements were performed in 50 patients planed for transcatheter aortic valve implantation in multiple planes: basal ring (short- and long-axis, mean diameter, area-derived diameter), coronal, sagittal, and 3-chamber projections. A theoretical model was developed taking into account the differences between the most reproducible MDCT measurements and transesophageal echocardiography to guide valve size choice.ResultsThe most reproducible measurements were the area-derived diameter and basal ring average diameter (inter-reader intraclass correlation coefficient: 0.87 [95% confidence interval: 0.81 to 0.92] and 0.80 [95% confidence interval: 0.70 to 0.87]; respectively; intrareader >0.90 for all readers). These were generally larger than transesophageal echocardiography diameters (mean difference of 1.5 ± 1.6 mm and 1.1 ± 1.7 mm, respectively). When a strategy of valve-sizing is undertaken using these CT measurements using an echocardiographic sizing scale, a different THV size would be selected in 44% and 40% of cases, respectively. When adjusting the sizing cutoffs to account for the differences in observed diameters, this was reduced to 10% to 12% (p < 0.01 for both, respectively).ConclusionsThe most reproducible MDCT measurements of the annulus are the area-derived diameter and basal ring average diameter, with derived values generally larger than those obtained with echocardiography. If MDCT is used for valve sizing, a strategy incorporating these differences may be important. MDCT using these easily derived measurements may be ideally suited to sizing transcatheter aortic valves as they account for the eccentricity of the aortic annulus, are reproducible, and are noninvasive
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