9 research outputs found

    Lorentz-Shaped Comet Dust Trail Cross Section from New Hybrid Visual and Video Meteor Counting Technique - Implications for Future Leonid Storm Encounters

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    A new hybrid technique of visual and video meteor observations was developed to provide high precision near real-time flux measurements for satellite operators from airborne platforms. A total of 33,000 Leonids. recorded on video during the 1999 Leonid storm, were watched by a team of visual observers using a video head display and an automatic counting tool. The counts reveal that the activity profile of the Leonid storm is a Lorentz profile. By assuming a radial profile for the dust trail that is also a Lorentzian, we make predictions for future encounters. If that assumption is correct, we passed 0.0003 AU deeper into the 1899 trailet than expected during the storm of 1999 and future encounters with the 1866 trailet will be less intense than. predicted elsewhere

    The 1999 Leonid Multi-Instrument Aircraft Campaign - An Early Review

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    The Leonid meteor storm of 1999 was observed from two B707-type research aircraft by a team of 35 scientists of seven nationalities over the Mediterranean Sea on Nov. 18, 1999. The mission was sponsored by various science programs of NASA, and offered the best possible observing conditions, free of clouds and at a prime location for viewing the storm. The 1999 mission followed a similar effort in 1998, improving upon mission strategy and scope. As before, spectroscopic and imaging experiments targeted meteors and persistent trains, but also airglow, aurora, elves and sprites. The research aimed to address outstanding questions in Planetary Science, Astronomy, Astrobiology and upper atmospheric research, including Aeronornie. In addition, near real-time flux measurements contributed to a USAF sponsored program for space weather awareness. An overview of the first results is given, which are discussed in preparation for future missions

    Cost-effectiveness of an intervention to reduce fear of cancer recurrence: the ConquerFear randomized controlled trial

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    Alongside a randomised controlled trial (RCT) evaluating the efficacy of the ConquerFear intervention for reducing fear of cancer recurrence in cancer survivors, the cost-effectiveness of this novel intervention was assessed, primarily from the health sector perspective, with broader societal productivity impacts assessed.Healthcare resource use was collected by a tailored cost diary. Incremental costs were calculated as the difference in total costs between the intervention and control groups. Incremental cost-effectiveness ratios (ICERs) were estimated by cost-effectiveness and cost-utility analyses, comparing incremental costs with incremental outcomes measured. Non-parametric bootstrap analysis was performed to evaluate uncertainty in costs and outcomes.Cancer survivors were randomised into ConquerFear (n= 121), or an active control group receiving relaxation training (n=101). Participants received on average 3.69 sessions, incurring an average cost of 297perperson,withnogroupdifference.TheITTanalysisresultsindicatedameanICER297 per person, with no group difference. The ITT analysis results indicated a mean ICER 34,300/QALY with average incremental cost 488andhealthgainof0.0142QALYs,fromthehealthcaresectorperspective.Bootstrapanalysisshowed30488 and health gain of 0.0142 QALYs, from the healthcare sector perspective. Bootstrap analysis showed 30% of iterations were dominant and overall 53% ICERs were cost-effective as judged by the commonly used 50,000/QALY threshold.The ConquerFear intervention is associated with a modest cost and may provide good value for money, but further evidence is needed. Long-term cost-effectiveness needs further investigation to capture full benefits from the intervention beyond the trial follow-up

    Trajectories of fear of recurrence in women with breast cancer

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    PurposeAlthough fear of recurrence (FCR) is common among cancer survivors, it remains unclear what factors predict initial levels (e.g., prior to surgery) or changes in FCR in the post-treatment period. Among women treated for breast cancer, this study evaluated the effects of demographic, clinical, symptom, and psychosocial adjustment characteristics on the initial (preoperative) levels of FCR and trajectories of FCR over 6 months following surgery.MethodsPrior to and for 6 months following breast cancer surgery, 396 women were assessed for demographic and clinical (disease and treatment) characteristics, symptoms, psychological adjustment characteristics, and quality of life (QOL). FCR was assessed using a four-item subscale from the QOL instrument. Hierarchical linear modeling was used to examine changes in FCR scores and to identify predictors of inter-individual differences in preoperative FCR levels and trajectories over 6 months.ResultsFrom before surgery to 6 months post-operatively, women with breast cancer showed a high degree of inter-individual variability in FCR. Preoperatively, women who lived with someone, experienced greater changes in spiritual life, had higher state anxiety, had more difficulty coping, or experienced more distress due to diagnosis or distress to family members reported higher FCR scores. Patients who reported better overall physical health and higher FCR scores at enrollment demonstrated a steeper decrease in FCR scores over time.ConclusionsThese findings highlight inter-individual heterogeneity in initial levels and changes in FCR over time among women undergoing breast cancer surgery. Further work is needed to identify and provide interventions for women experiencing FCR during and after breast cancer treatment

    Polygenic risk scores for prediction of breast cancer and breast cancer subtypes

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    Abstract Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57–1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628–0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs

    Identification of six new susceptibility loci for invasive epithelial ovarian cancer.

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