Applicability of the langley method for non-geostationary in-orbit satellite effective isotropic radiated power estimation

The Effective Isotropic Radiated Power (EIRP) is a crucial parameter characterizing the transmitting antennas of a radiofrequency satellite link. During the satellite commissioning phase, the requirements compliance of communication subsystems is tested. One of the required tests concerns the EIRP of the satellite transmitting antenna. Ground-based power measurements of the satellite-emitted signal are collected to measure EIRP, provided that an estimate of the atmospheric losses is available from independent ancillary measurements or model data. This paper demonstrates the applicability of the so-called Langley method to infer EIRP and atmospheric attenuation simultaneously from ground-based power measurements, with no need for ancillary measurements. It is shown that the proposed method gives results similar to more traditional methods, without prior information on atmospheric attenuation. Thus, the proposed method can be applied to monitor EIRP throughout the satellite life-time from ground-based power measurements alone

Second and third trimester estimation of gestational age using ultrasound or maternal symphysis-fundal height measurements: A systematic review.

Background Accurate assessment of gestational age (GA) is important for managing pregnancies at an individual level and monitoring preterm birth rates at a population level. Objectives As many women first seek antenatal care in late pregnancy, our aim was to assess the methodology of studies reporting equations for estimating GA after 20 weeks’ gestation using ultrasound or symphysis-fundal height (SFH) measurements. Search strategy Six electronic databases were searched for studies published from January 1970 to April 2021. Selection criteria Studies were included if they contained a formula using SFH or ultrasound-measured biometry to estimate GA after 20 weeks in healthy singleton pregnancies. Data collection and analysis Two reviewers and a statistician reviewed study design, statistical methods, and reporting methods using 29 criteria. Each article was awarded an overall quality score, predefined as the percentage of the 29 criteria scored at low risk of bias. 95% prediction intervals were calculated for studies that used recommended first trimester dating to confirm true GA. Main results The search yielded 4209 results. Ninety-seven full-text articles were included in the analysis. The mean quality score was 32% (range 7%–97%). Only 10 articles scored low risk in 18 or more criteria. Their formulas estimated GA using one or more ultrasound-measured biometry parameters and SFH measurements. Twenty-three articles used recommended first trimester dating. A single-parameter formula using transcerebellar diameter (TCD) gave the lowest 95% prediction interval. Conclusions There is considerable methodological heterogeneity in studies developing equations for estimating GA. Formulas using ultrasound-based measurements more accurately estimated GA after 20 weeks than formulas using SFH measurement. While the clinical priority remains promotion of early engagement with antenatal care, we suggest unified standards for GA and growth assessment

Reporting guidelines used varying methodology to develop recommendations

Background and Objectives We investigated the developing methods of reporting guidelines in the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) Network's database. Methods In October 2018, we screened all records and excluded those not describing reporting guidelines from further investigation. Twelve researchers performed duplicate data extraction on bibliometrics, scope, development methods, presentation, and dissemination of all publications. Descriptive statistics were used to summarize the findings. Results Of the 405 screened records, 262 described a reporting guidelines development. The number of reporting guidelines increased over the past 3 decades, from 5 in the 1990s and 63 in the 2000s to 157 in the 2010s. Development groups included 2–151 people. Literature appraisal was performed during the development of 56% of the reporting guidelines; 33% used surveys to gather external opinion on items to report; and 42% piloted or sought external feedback on their recommendations. Examples of good reporting for all reporting items were presented in 30% of the reporting guidelines. Eighteen percent of the reviewed publications included some level of spin. Conclusion Reporting guidelines have been developed with varying methodology. Reporting guideline developers should use existing guidance and take an evidence-based approach, rather than base their recommendations on expert opinion of limited groups of individuals

Evaluation of clinical prediction models (part 1):from development to external validation

Evaluating the performance of a clinical prediction model is crucial to establish its predictive accuracy in the populations and settings intended for use. In this article, the first in a three part series, Collins and colleagues describe the importance of a meaningful evaluation using internal, internal-external, and external validation, as well as exploring heterogeneity, fairness, and generalisability in model performance

Evaluation of clinical prediction models (part 1): from development to external validation

Evaluating the performance of a clinical prediction model is crucial to establish its predictive accuracy in the populations and settings intended for use. In this article, the first in a three part series, Collins and colleagues describe the importance of a meaningful evaluation using internal, internal-external, and external validation, as well as exploring heterogeneity, fairness, and generalisability in model performance

Reminding peer reviewers of reporting guideline items to improve completeness in published articles: primary results of 2 randomized trials

Importance:  Numerous studies have shown that adherence to reporting guidelines is suboptimal. Objective:  To evaluate whether asking peer reviewers to check if specific reporting guideline items were adequately reported would improve adherence to reporting guidelines in published articles. Design, Setting, and Participants:  Two parallel-group, superiority randomized trials were performed using manuscripts submitted to 7 biomedical journals (5 from the BMJ Publishing Group and 2 from the Public Library of Science) as the unit of randomization, with peer reviewers allocated to the intervention or control group. Interventions:  The first trial (CONSORT-PR) focused on manuscripts that presented randomized clinical trial (RCT) results and reported following the Consolidated Standards of Reporting Trials (CONSORT) guideline, and the second trial (SPIRIT-PR) focused on manuscripts that presented RCT protocols and reported following the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guideline. The CONSORT-PR trial included manuscripts that described RCT primary results (submitted July 2019 to July 2021). The SPIRIT-PR trial included manuscripts that contained RCT protocols (submitted June 2020 to May 2021). Manuscripts in both trials were randomized (1:1) to the intervention or control group; the control group received usual journal practice. In the intervention group of both trials, peer reviewers received an email from the journal that asked them to check whether the 10 most important and poorly reported CONSORT (for CONSORT-PR) or SPIRIT (for SPIRIT-PR) items were adequately reported in the manuscript. Peer reviewers and authors were not informed of the purpose of the study, and outcome assessors were blinded. Main Outcomes and Measures:  The difference in the mean proportion of adequately reported 10 CONSORT or SPIRIT items between the intervention and control groups in published articles. Results:  In the CONSORT-PR trial, 510 manuscripts were randomized. Of those, 243 were published (122 in the intervention group and 121 in the control group). A mean proportion of 69.3% (95% CI, 66.0%-72.7%) of the 10 CONSORT items were adequately reported in the intervention group and 66.6% (95% CI, 62.5%-70.7%) in the control group (mean difference, 2.7%; 95% CI, −2.6% to 8.0%). In the SPIRIT-PR trial, of the 244 randomized manuscripts, 178 were published (90 in the intervention group and 88 in the control group). A mean proportion of 46.1% (95% CI, 41.8%-50.4%) of the 10 SPIRIT items were adequately reported in the intervention group and 45.6% (95% CI, 41.7% to 49.4%) in the control group (mean difference, 0.5%; 95% CI, −5.2% to 6.3%). Conclusions and Relevance:  These 2 randomized trials found that it was not useful to implement the tested intervention to increase reporting completeness in published articles. Other interventions should be assessed and considered in the future. Trial Registration:  ClinicalTrials.gov Identifiers: NCT05820971 (CONSORT-PR) and NCT05820984 (SPIRIT-PR

Review and assessment of latent and sensible heat flux accuracy over the global oceans

For over a decade, several research groups have been developing air-sea heat flux information over the global ocean, including latent (LHF) and sensible (SHF) heat fluxes over the global ocean. This paper aims to provide new insight into the quality and error characteristics of turbulent heat flux estimates at various spatial and temporal scales (from daily upwards). The study is performed within the European Space Agency (ESA) Ocean Heat Flux (OHF) project. One of the main objectives of the OHF project is to meet the recommendations and requirements expressed by various international programs such as the World Research Climate Program (WCRP) and Climate and Ocean Variability, Predictability, and Change (CLIVAR), recognizing the need for better characterization of existing flux errors with respect to the input bulk variables (e.g. surface wind, air and sea surface temperatures, air and surface specific humidities), and to the atmospheric and oceanic conditions (e.g. wind conditions and sea state). The analysis is based on the use of daily averaged LHF and SHF and the asso- ciated bulk variables derived from major satellite-based and atmospheric reanalysis products. Inter-comparisons of heat flux products indicate that all of them exhibit similar space and time patterns. However, they also reveal significant differences in magnitude in some specific regions such as the western ocean boundaries during the Northern Hemisphere winter season, and the high southern latitudes. The differences tend to be closely related to large differences in surface wind speed and/or specific air humidity (for LHF) and to air and sea temperature differences (for SHF). Further quality investigations are performed through comprehensive comparisons with daily-averaged LHF and SHF estimated from moorings. The resulting statistics are used to assess the error of each OHF product. Consideration of error correlation between products and observations (e.g., by their assimilation) is also given. This reveals generally high noise variance in all products and a weak signal in common with in situ observations, with some products only slightly better than others. The OHF LHF and SHF products, and their associated error characteristics, are used to compute daily OHF multiproduct-ensemble (OHF/MPE) estimates of LHF and SHF over the ice-free global ocean on a 0.25° × 0.25° grid. The accuracy of this heat multiproduct, determined from comparisons with mooring data, is greater than for any individual product. It is used as a reference for the anomaly characterization of each individual OHF product

Completeness of Reporting in Diet- and Nutrition-Related Randomized Controlled Trials and Systematic Reviews With Meta-Analysis:Protocol for 2 Independent Meta-Research Studies

Background: Journal articles describing randomized controlled trials (RCTs) and systematic reviews with meta-analysis of RCTs are not optimally reported and often miss crucial details. This poor reporting makes assessing these studies’ risk of bias or reproducing their results difficult. However, the reporting quality of diet- and nutrition-related RCTs and meta-analyses has not been explored. Objective: We aimed to assess the reporting completeness and identify the main reporting limitations of diet- and nutrition-related RCTs and meta-analyses of RCTs, estimate the frequency of reproducible research practices among these RCTs, and estimate the frequency of distorted presentation or spin among these meta-analyses. Methods: Two independent meta-research studies will be conducted using articles published in PubMed-indexed journals. The first will include a sample of diet- and nutrition-related RCTs; the second will include a sample of systematic reviews with meta-analysis of diet- and nutrition-related RCTs. A validated search strategy will be used to identify RCTs of nutritional interventions and an adapted strategy to identify meta-analyses in PubMed. We will search for RCTs and meta-analyses indexed in 1 calendar year and randomly select 100 RCTs (June 2021 to June 2022) and 100 meta-analyses (July 2021 to July 2022). Two reviewers will independently screen the titles and abstracts of records yielded by the searches, then read the full texts to confirm their eligibility. The general features of these published RCTs and meta-analyses will be extracted into a research electronic data capture database (REDCap; Vanderbilt University). The completeness of reporting of each RCT will be assessed using the items in the CONSORT (Consolidated Standards of Reporting Trials), its extensions, and the TIDieR (Template for Intervention Description and Replication) statements. Information about practices that promote research transparency and reproducibility, such as the publication of protocols and statistical analysis plans will be collected. There will be an assessment of the completeness of reporting of each meta-analysis using the items in the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and collection of information about spin in the abstracts and full-texts. The results will be presented as descriptive statistics in diagrams or tables. These 2 meta-research studies are registered in the Open Science Framework. Results: The literature search for the first meta-research retrieved 20,030 records and 2182 were potentially eligible. The literature search for the second meta-research retrieved 10,918 records and 850 were potentially eligible. Among them, random samples of 100 RCTs and 100 meta-analyses were selected for data extraction. Data extraction is currently in progress, and completion is expected by the beginning of 2023. Conclusions: Our meta-research studies will summarize the main limitation on reporting completeness of nutrition- or diet-related RCTs and meta-analyses and provide comprehensive information regarding the particularities in the reporting of intervention studies in the nutrition field