scholarly journals A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part II: Primary and Associated Analyses

2011 ◽  
Vol 50 (7) ◽  
pp. 1448-1458 ◽  
Author(s):  
Michael J. Manton ◽  
Loredana Warren
Keyword(s):  
Secondary Analysis ◽  
Maximum Level ◽  
Cloud Microphysics ◽  
Target Area ◽  
Primary Target ◽  
Primary Analysis ◽  
Significance Level ◽  
Southeastern Australia ◽  
Secondary Analyses ◽  
Seeding Material

AbstractThe Snowy Precipitation Enhancement Research Project (SPERP) was undertaken in winters from May 2005 to June 2009 in the Snowy Mountains region of southeastern Australia. Part I of this paper describes the design and implementation of the project, as well as the characteristics of the key datasets collected during the field phase. The primary analysis in this paper (Part II) shows an unequivocal impact on the targeting of seeding material, with the maximum level of silver in snow samples collected from the primary target area found to be significantly greater in seeded than unseeded experimental units (EUs). A positive but not statistically significant impact on precipitation was found. Further analysis shows that a substantial source of uncertainty in the estimation of the impacts of seeding on precipitation is associated with EUs where the seeding generators operated for relatively few hours. When the analysis is repeated using only EUs with more than 45 generator hours, the increase in precipitation in the primary target area is 14% at the 8% significance level. When applying that analysis to the overall target area, the precipitation increase is 14% at the 3% significance level. A secondary analysis of the ratio of silver to indium in snow supports the hypothesis that seeding material affected the cloud microphysics. Other secondary analyses reveal that seeding had an impact on virtually all of the physical variables examined in a manner consistent with the seeding hypothesis.

Abstract P533: Incidence and Outcomes of Thrombectomy Rescue Therapies in Acute Basilar Artery Occlusions

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Ronda Lun ◽  
Greg B Walker ◽  
David Weisenburger-Lile ◽  
Bertrand Lapergue ◽  
Adrien Guenego ◽  
...  
Keyword(s):  
Primary Outcome ◽  
Secondary Analysis ◽  
Hematoma Expansion ◽  
Primary Analysis ◽  
Predictive Values ◽  
Previous Definition ◽  
Secondary Analyses ◽  
Revised Definitions ◽  
Definition Of ◽  
Sensitivity Specificity

Background: Hematoma expansion (HE) is an important therapeutic target in intracerebral hemorrhage. Recently proposed HE definitions have not been validated, and no previous definition has accounted for withdrawal of care (WOC). Objective: To compare conventional and revised definitions of hematoma expansion (HE), while accounting for WOC. Methods: We analyzed data from the ATACH-2 trial, comparing revised definitions of HE incorporating intraventricular hemorrhage (IVH) expansion to the conventional definition of “≥6 mL or ≥33%”. The primary outcome was modified Rankin Scale of 4-6 at 90-days. We calculated the incidence, sensitivity, specificity, positive and negative predictive values, and c- statistic for all definitions of HE. Definitions were compared using non-parametric methods. Secondary analyses were performed after removing patients who experienced WOC. Results: Primary analysis included 948 patients. Using the conventional definition, the sensitivity was 37.1% and specificity was 83.2% for the primary outcome. Sensitivity improved with all three revised definitions (53.3%, 48.7%, and 45.3%, respectively), with minimal change to specificity (78.4%, 80.5%, and 81.0%, respectively). The greatest improvement was seen with the definition “≥6 mL or ≥33% or any IVH”, with increased c -statistic from 60.2% to 65.9% (p < 0.001). Secondary analysis excluded 46 participants who experienced WOC. The revised definitions outperformed the conventional definition in this population as well, with the greatest improvement in c -statistic using “≥6 mL or ≥33% or any IVH” (58.1% vs 64.1%, p < 0.001). Conclusions: HE definitions incorporating intraventricular expansion outperformed conventional definitions for predicting poor outcome, even after accounting for care limitations.

scholarly journals A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part I: Project Design and Response Variables

2011 ◽  
Vol 50 (7) ◽  
pp. 1432-1447 ◽  
Author(s):  
Michael J. Manton ◽  
Loredana Warren ◽  
Suzanne L. Kenyon ◽  
Andrew D. Peace ◽  
Shane P. Bilish ◽  
...  
Keyword(s):  
Supercooled Liquid ◽  
Field Studies ◽  
Control Area ◽  
Target Area ◽  
Fixed Target ◽  
Southeastern Australia ◽  
Seeding Material ◽  
Static Seeding ◽  
A Site ◽  
Precipitation Enhancement

AbstractThe Snowy Precipitation Enhancement Research Project (SPERP) was undertaken from May 2005 to June 2009 in the Snowy Mountains of southeastern Australia with the aim of enhancing snowfall in westerly flows associated with winter cold fronts. Building on earlier field studies in the region, SPERP was developed as a confirmatory experiment of glaciogenic static seeding using a silver-chloroiodide material dispersed from ground-based generators. Seeding of 5-h experimental units (EUs) was randomized with a seeding ratio of 2:1. A total of 107 EUs were undertaken at suitable times, based on surface and upper-air observations. Indium (III) oxide was released during all EUs for comparison of indium and silver concentrations in snow in seeded and unseeded EUs to test the targeting of seeding material. A network of gauges was deployed at 44 sites across the region to detect whether precipitation was enhanced in a fixed target area of 832 km2, using observations from a fixed control area to estimate the natural precipitation in the target. Additional measurements included integrated supercooled liquid water at a site in the target area and upper-air data from a site upwind of the target.

Effectiveness of bevacizumab (BV) beyond disease progression in metastatic colorectal cancer (mCRC): Analyses by sex in the ARIES observational cohort study (OCS).

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 514-514
Author(s):  
Allen Lee Cohn ◽  
Herbert Hurwitz ◽  
Tanios S. Bekaii-Saab ◽  
Johanna C. Bendell ◽  
Mark Kozloff ◽  
...  
Keyword(s):  
Disease Progression ◽  
Cox Regression ◽  
Secondary Analysis ◽  
Average Risk ◽  
Primary Analysis ◽  
Men And Women ◽  
Hazard Ratios ◽  
Secondary Analyses ◽  
Observational Cohort ◽  
Clinical Trial Information

514 Background: Randomized trials and OCSs have demonstrated that BV treatment in 1st-line (1L), in 2L, and across multiple lines is associated with longer survival in patients (pts) with mCRC. This analysis was aimed at comparing the effectiveness of BV after 1st disease progression (PD) between male and female mCRC pts who received 1L BV-containing therapy in a real-world setting. Methods: ARIES is a large, prospective OCS that enrolled pts who received BV and chemotherapy (CT) for 1L mCRC. Post-PD effectiveness was assessed for men and women characterizing BV use by cumulative and dichotomous approaches. The primary analysis treated BV exposure as cumulative BV doses after 1st PD and post-progression overall survival (ppOS) as the time from 1st PD to death. A time-dependent Cox regression model was fitted to assess the effect of cumulative BV exposure on ppOS, while controlling for potential confounders. A dichotomous secondary analysis characterized BV exposure as receipt of CT + BV (BBP) or CT alone (No BBP) within 2 months after PD and ppOS as time from 1st PD + 2 months to death. Results: Among the 1,550 1L mCRC pts enrolled, 1,199 (532 women) had PD. In the primary analysis, hazard ratios (HRs) for ppOS decreased, on average, by 1.2% with each additional BV dose. When stratified by sex, the average risk reduction per BV dose over 15 doses was 1.8% in women and 0.7% in men. In the secondary analysis that included 331 women (BBP, 180; No BBP, 151) and 417 men (BBP, 245, No BBP, 172) who received BV ± CT within 2 months post-PD, the HRs for ppOS with BBP treatment were 0.46 (95% CI, 0.35–0.59) in women and 0.52 (95% CI, 0.41–0.67) in men. Statistical interaction tests for differences in the effectiveness of BV between men and women were negative for primary and secondary analyses (P of 0.58 and 0.77). Protocol-specified adverse events occurred in 17.8% of women and 10.2% of men in the BBP population; this difference was largely related to rates of hypertension (8.3% vs 2.4%, respectively). Conclusions: In ARIES, the effectiveness of BV after first PD was not statistically different between women and men with mCRC. Clinical trial information: NCT00388206.

Hierarchical Modelling of Facial Perceptions: A Secondary Analysis of Aggressiveness Ratings

2020 ◽  
Author(s):  
Mark Christopher Adkins ◽  
Nataly Beribisky ◽  
Stephan Bonfield ◽  
Linda Farmus
Keyword(s):  
Factor Analysis ◽  
Mixed Model ◽  
Structural Information ◽  
Secondary Analysis ◽  
Specific Factor ◽  
Primary Analysis ◽  
Model Framework ◽  
Psychological Science ◽  
Individual Traits ◽  
Confirmatory Factor

The Psychological Science Accelerator’s (PSA) primary project tested for latent structure using exploratory factor analysis and confirmatory factor analysis but we decided to diverge from this approach and model individual traits separately. Our interest mainly was in examining the interplay between “stimulus ethnicity” and “stimulus sex” to discover how differing levels of these criterion differ across region, country, lab etc. While the necessary and prerequisite hierarchical structural information about each trait could certainly be found within the primary project’s dataset, we did not assume that any specific factor structure from the PSA’s primary analysis would necessarily hold, therefore we based our decision to model the data from each trait separately using a mixed model framework.

Has the SARS-CoV-2 outbreak had an impact on uptake of digital cessation support in UK smokers? An interrupted time series analysis (Preprint)

2020 ◽  
Author(s):  
Olga Perski ◽  
Aleksandra Herbec ◽  
Lion Shahab ◽  
Jamie Brown
Keyword(s):  
Time Series ◽  
Smoking Cessation ◽  
Secondary Analysis ◽  
Interrupted Time Series ◽  
Step Change ◽  
Outcome Variable ◽  
Primary Analysis ◽  
Increasing Trend ◽  
The Uk ◽  
Temporary Closure

BACKGROUND The SARS-CoV-2 outbreak may motivate smokers to attempt to stop in greater numbers. However, given the temporary closure of UK stop smoking services and vape shops, smokers attempting to quit may instead seek out digital support, such as websites and smartphone apps. OBJECTIVE We examined, using an interrupted time series approach, whether the SARS-CoV-2 outbreak has been associated with a step change or increasing trend in UK downloads of an otherwise popular smoking cessation app, Smoke Free. METHODS Data were from daily and non-daily adult smokers in the UK who had downloaded the Smoke Free app between 1 January 2020 and 31 March 2020 (primary analysis) and 1 January 2019 and 31 March 2020 (secondary analysis). The outcome variable was the number of downloads aggregated at the 12-hourly (primary analysis) or daily level (secondary analysis). The explanatory variable was the start of the SARS-CoV-2 outbreak, operationalised as 1 March 2020 (primary analysis) and 15 January 2020 (secondary analysis). Generalised Additive Mixed Models adjusted for relevant covariates were fitted. RESULTS Data were collected on 45,105 (primary analysis) and 119,881 (secondary analysis) users. In both analyses, there was no evidence for a step change or increasing trend in downloads attributable to the start of the SARS-CoV-2 outbreak. CONCLUSIONS In the UK, between 1 January 2020 and 31 March 2020, and between 1 January 2019 and 31 March 2020, there was no evidence that the SARS-CoV-2 outbreak has been associated with a surge in downloads of a popular smoking cessation app. CLINICALTRIAL osf.io/zan2s

Cultural variation in children's observation during a demonstration

2005 ◽  
Vol 29 (4) ◽  
pp. 282-291 ◽  
Author(s):  
Rebeca Mejía-Arauz ◽  
Barbara Rogoff ◽  
Ruth Paradise
Keyword(s):  
Secondary Analysis ◽  
Cultural Variation ◽  
Formal Schooling ◽  
Primary Analysis ◽  
Extensive Experience ◽  
Children’S Learning ◽  
Mexican Heritage ◽  
European Heritage ◽  
Us Children ◽  
Children's Learning

Ethnographic research indicates that in a number of cultural communities, children's learning is organised around observation of ongoing activities, contrasting with heavy use of explanation in formal schooling. The present research examined the extent to which first- to third-grade children observed an adult's demonstration of how to fold origami figures or observed the folding of two slightly older children who also were trying to make the figures, without requesting further information. In the primary analysis, 10 Mexican heritage US children observed without requesting additional information to a greater extent than 10 European heritage US children. Consistent with the ethnographic literature, these two groups differed in the extent of their family's involvement in schooling; hence, we explored the relationship with maternal schooling in a secondary analysis. An additional 11 children of Mexican heritage whose mothers had extensive experience in formal school (at least a high school education) showed a pattern more like that of the European heritage children, whose mothers likewise had extensive experience in school, compared with the Mexican heritage children whose mothers had only basic schooling (an average of 7.7 grades). The results suggest that a constellation of cultural traditions that organise children's learning experiences—including Western schooling—may play an important role in children's learning through observation and explanation.

Association between Number of Prior Cesareans and Early Preterm Delivery in Women with Abnormal Placentation

2020 ◽  
Author(s):  
Ayamo Oben ◽  
Elizabeth B. Ausbeck ◽  
Melissa N. Gazi ◽  
Akila Subramaniam ◽  
Lorie M. Harper ◽  
...  
Keyword(s):  
Preterm Delivery ◽  
Preterm Labor ◽  
Placenta Previa ◽  
Secondary Analysis ◽  
Blood Products ◽  
Primary Analysis ◽  
Logistic Regression Models ◽  
Placenta Accreta Spectrum ◽  
Nicu Admission ◽  
Early Preterm Birth

Objective Delivery timing at 34 to 36 weeks is nationally recommended for pregnancies complicated by placenta accreta spectrum (PAS). However, it has recently been suggested that those with ≥2 prior cesarean deliveries (CD) and PAS should be delivered earlier than 34 weeks because of a higher risk of unscheduled delivery and complications. We sought to evaluate whether the number of prior CD in women with PAS is associated with early preterm delivery (PTD) (<34 weeks). We also evaluated the same relationship in women with placenta previa alone (without PAS). Study Design This is a secondary analysis of a multicenter and observational study that included women with prior CD (maternal–fetal medicine unit cesarean registry). Women with a diagnosis of PAS (regardless of placenta previa) were included for our primary analysis, and women with known placenta previa (without a component of PAS) were independently analyzed in a second analysis. Two groups of patients from the registry were studied: patients with PAS (regardless of placenta previa) and patients with placenta previa without PAS. The exposure of interest was the number of prior CD: ≥2 CD compared with <2 CD. The primary outcome was PTD <34 weeks. Secondary outcomes included preterm labor requiring hospitalization or tocolysis, transfusion of blood products, composites of maternal and neonatal morbidities, and NICU admission. Outcomes by prior CD number groups were compared in both cohorts. Backward selection was used to identify parsimonious logistic regression models. Results There were 194 women with PAS, 97 (50%) of whom had <2 prior CD and 97 (50%) of whom had ≥2 prior CD. The rate of PTD <34 weeks in women with ≥2 prior CD compared with <2 in the setting of PAS was 23.7 versus 29.9%, p = 0.27; preterm labor requiring hospitalization was 24.7 versus 13.5%; p = 0.05. The rates of plasma transfusion were increased with ≥2 prior CD (29.9 vs. 17.5%, p = 0.04), but there were no differences in transfusion of other products or in composite maternal or neonatal morbidities. After multivariable adjustments, having ≥2 CDs was not associated with PTD <34 weeks in women with PAS (adjusted odds ratio (aOR): 0.73, 95% confidence interval [CI]: 0.39–13.8) despite an association with preterm labor requiring hospitalization (aOR: 2.69; 95% CI: 1.15–6.32). In our second analysis, there were 687 women with placenta previa, 633 (92%) with <2 prior CD, and 54 (8%) with ≥2 prior CD. The rate of PTD <34 weeks with ≥2 CD in the setting of placenta previa was not significantly increased (27.8 vs. 22.1%, aOR: 1.49; 95% CI: 0.77–2.90, p = 0.08); the maternal composite outcome (aOR: 4.85; 95% CI: 2.43–9.67) and transfusion of blood products (aOR: 6.41; 95% CI: 2.30–17.82) were noted to be higher in the group with ≥2 prior CD. Conclusion Women with PAS who have had ≥2 prior CD as compared with women with <2 prior CD did not appear to have a higher risk of complications leading to delivery prior to 34 weeks. As such, considering the associated morbidity with early preterm birth, we would not recommend scheduled delivery prior to 34 weeks in this population. Key Points

scholarly journals Endovascular thrombectomy time metrics in the era of COVID-19: observations from the Society of Vascular and Interventional Neurology Multicenter Collaboration

2021 ◽  
pp. neurintsurg-2020-017205
Author(s):  
Alexandra L Czap ◽  
Alicia M Zha ◽  
Jacob Sebaugh ◽  
Ameer E Hassan ◽  
Julie G Shulman ◽  
...  
Keyword(s):  
Care Delivery ◽  
Control Period ◽  
Secondary Analysis ◽  
Primary Analysis ◽  
Vessel Occlusion ◽  
Endovascular Thrombectomy ◽  
Final Multivariable Model ◽  
Multivariable Regression ◽  
Multi Center Study ◽  
Multivariable Adjustment

BackgroundUnprecedented workflow shifts during the coronavirus disease 2019 (COVID-19) pandemic have contributed to delays in acute care delivery, but whether it adversely affected endovascular thrombectomy metrics in acute large vessel occlusion (LVO) is unknown.MethodsWe performed a retrospective review of observational data from 14 comprehensive stroke centers in nine US states with acute LVO. EVT metrics were compared between March to July 2019 against March to July 2020 (primary analysis), and between state-specific pre-peak and peak COVID-19 months (secondary analysis), with multivariable adjustment.ResultsOf the 1364 patients included in the primary analysis (51% female, median NIHSS 14 [IQR 7–21], and 74% of whom underwent EVT), there was no difference in the primary outcome of door-to-puncture (DTP) time between the 2019 control period and the COVID-19 period (median 71 vs 67 min, P=0.10). After adjustment for variables associated with faster DTP, and clustering by site, there remained a trend toward shorter DTP during the pandemic (βadj=-73.2, 95% CI −153.8–7.4, Pp=0.07). There was no difference in DTP times according to local COVID-19 peaks vs pre-peak months in unadjusted or adjusted multivariable regression (βadj=-3.85, 95% CI −36.9–29.2, P=0.80). In this final multivariable model (secondary analysis), faster DTP times were significantly associated with transfer from an outside institution (βadj=-46.44, 95% CI −62.8 to – -30.0, P<0.01) and higher NIHSS (βadj=-2.15, 95% CI −4.2to – -0.1, P=0.05).ConclusionsIn this multi-center study, there was no delay in EVT among patients treated for intracranial occlusion during the COVID-19 era compared with the pre-COVID era.

071 Natalizumab extended interval dosing (EID) is associated with a significant reduction in progressive multifocal leukoencephalopathy (PML) risk compared with standard interval dosing (SID) in the touch® prescribing program

2018 ◽  
Vol 89 (6) ◽  
pp. A29.2-A29 ◽  
Author(s):  
Lana Zhovtis Ryerson ◽  
John Foley ◽  
Ih Chang ◽  
Ilya Kister ◽  
Gary Cutter ◽  
...  
Keyword(s):  
Cox Regression ◽  
Jc Virus ◽  
Secondary Analysis ◽  
Statistical Analysis Plan ◽  
Rank Test ◽  
Primary Analysis ◽  
Standard Interval ◽  
Kaplan Meier ◽  
Hazard Ratios ◽  
Dosing Intervals

IntroductionNatalizumab, approved for 300 mg intravenous every-4-weeks dosing, is associated with PML risk. Prior studies have been inconclusive regarding EID’s impact on PML risk. The US REMS program (TOUCH) offers the largest data source that can inform on PML risk in patients on EID. This analysis aimed to determine whether natalizumab EID is associated with reduced PML risk compared with SID.MethodsInvestigators developed SID and EID definitions and finalised the statistical analysis plan while blinded to PML events. Average dosing intervals (ADIs) were ≥3 to<5 weeks for SID and >5 to≤12 weeks for EID. The primary analysis assessed ADI in the last 18 months of infusion history. The secondary analysis identified any prolonged period of EID at any time in the infusion history. The tertiary analysis assessed ADI over the full infusion history. Only anti-JC virus antibody positive (JCV Ab+) patients with dosing intervals≥3 to≤12 weeks were included. PML hazard ratios (HRs) were compared using adjusted Cox regression models and Kaplan-Meier estimates.ResultsAnalyses included 13,132 SID and 1988 EID patients (primary), 15,424 SID and 3331 EID patients (secondary), and 23,168 SID and 815 EID patients (tertiary). In primary analyses, ADI (days) was 30 for SID and 37 for EID; median exposure (months) was 44 for SID and 59 for EID. Most EID patients received >2 years SID prior to EID. The PML HR (95% CI) was 0.06 (0.01–0.22; p<0.001) for primary analysis and 0.12 (0.05–0.29; p<0.001) for secondary analysis (both in favour of EID); no EID PML cases were observed in tertiary analyses (Kaplan-Meier log-rank test p=0.02).ConclusionIn JCV Ab +patients, natalizumab EID is associated with a clinically and statistically significant reduction in PML risk as compared with SID. As TOUCH does not collect effectiveness data, further studies are needed.Study supportBiogen

Abstract 66: Causal Associations Between Genetically-determined Smoking and Risk of Subarachnoid Hemorrhage

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Julian N Acosta ◽  
Cameron Both ◽  
Stacy Brown ◽  
Audrey Leasure ◽  
Kevin N Vanent ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Smoking Behavior ◽  
Population Based ◽  
European Ancestry ◽  
Ratio Method ◽  
Polygenic Risk Score ◽  
Primary Analysis ◽  
Increased Risk ◽  
Secondary Analyses ◽  
Genetically Determined

Introduction: Animal and observational studies indicate that smoking is a risk factor for aneurysm formation and rupture, leading to subarachnoid hemorrhage (SAH). However, a definitive causal relationship between smoking and SAH has not been established. We leveraged the causal properties of mutation-disease associations to test the hypothesis that smoking is causally linked to SAH. Methods: We conducted a one-sample Mendelian Randomization (MR) study within the UK Biobank, a prospective, population-based observational study. We restricted the analysis to study participants with genetically-confirmed European ancestry. SAH cases were ascertained using previously validated codes. As the instrument, we built a polygenic risk score (PRS) using independent (R2<0.1) genetic variants known to be associated (p<5x10-8) with smoking. For the primary MR analysis, we implemented the ratio method using the estimates obtained from testing the PRS for association with risk of SAH and smoking. In secondary analyses, we implemented the inverse-variance weighted (IVW) and weighted median (WM) methods. Pleiotropy was assessed via the MR-Egger approach. Results: We included a total of 408,622 individuals in this study (mean age 57 [SD 8], female sex 220,944 [54%]). Of these, 132,568 (32%) ever smoked regularly and 904 (0.22%) had an SAH. Each additional standard deviation of the smoking PRS was associated with a 9% increased risk of SAH (OR 1.09, 95%CI 1.03-1.17; p=0.006) and 21% increased risk of smoking (OR 1.21, 95%CI 1.2-1.21; p=1x10-16). In the primary analysis, genetically-determined smoking was associated with a 63% increase in risk of SAH (OR 1.63, 95%CI 1.15-2.30; p=0.006). Secondary analyses using the IVW method (OR 1.57, 95%CI 1.13-2.17; p=0.007) and the WM method (OR 1.74, 95%CI 1.06-2.86; p=0.028) yielded comparable results. There was no significant pleiotropy (MR-Egger intercept p=0.38). Conclusion: Genetically-determined smoking is strongly associated with the risk of SAH. These findings provide evidence for a causal link between smoking and the occurrence of this often-debilitating condition. Interventions aimed at reducing smoking behavior could offer significant benefits, especially to those at high risk of SAH.

Sign in / Sign up

Export Citation Format

Share Document