Replication Studies
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2021 ◽  
Bryan Lougheed ◽  
Brett Metcalfe

Abstract. We use a single foraminifera enabled, holistic hydroclimate-to-sediment transient modelling approach to fundamentally evaluate the efficacy of discrete-depth individual foraminifera analysis (IFA) for reconstructing past sea surface temperature (SST) variability from deep-sea sediment archives, a method that has been used for, amongst other applications, reconstructing El Niño Southern Oscillation (ENSO). The computer model environment allows us to strictly control for variables such as sea surface temperature (SST), foraminifera species abundance response to SST, as well as depositional processes such as sediment accumulation rate (SAR) and bioturbation depth (BD), and subsequent laboratory processes such as sample size and machine error. Examining a number of best-case scenarios, we find that IFA-derived reconstructions of past SST variability are sensitive to all of the aforementioned variables. Running 100 ensembles for each scenario, we find that the influence of bioturbation upon IFA-derived SST reconstructions, combined with typical samples sizes employed in the field, produces noisy SST reconstructions with poor correlation to the original SST distribution in the water. This noise is especially apparent for values near the edge of the SST distribution, which is the distribution region of particular interest for, e.g., ENSO. The noise is further increased in the case of increasing machine error, decreasing SAR and decreasing sample size. We also find poor agreement between ensembles, underscoring the need for replication studies in the field to confirm findings at particular sites and time periods. Furthermore, we show that a species’ abundance response to SST could in theory bias IFA-derived SST reconstructions, which can have consequences when comparing IFA-derived SST from markedly different mean climate states. We provide a number of idealised simulations spanning a number of SAR, sample size, machine error and species abundance scenarios, which can help assist researchers in the field to determine under which conditions they could expect to retrieve significant results.

2021 ◽  
Aurélien Allard ◽  
Simine Vazire

The credibility revolution in social science has highlighted the importance of conducting replication studies. Despite this growing awareness, the value of direct replications is still hotly debated. In this article, we identify three main functions served by replication. We argue that replications are valuable when they target important or influential studies, when they provide a general estimate of the replicability rate of a population of published articles, and when they create incentives favoring replicable research. We therefore argue that the scientific community should organize systematic large-scale replication audits of two subsets of journals’ published articles: a subset of the most-cited articles, and a subset of randomly selected articles that would provide an estimate of the replicability of the journals' articles. These replicability audits should pave the way for more general quality audits of scientific journals.

Michael E. Morrell ◽  
Genevieve Fuji Johnson ◽  
Laura W Black

Scholars have increasingly urged researchers to evaluate prior findings through replication studies that can help test, refine, and extend claims made in previous research. We agree that this is an important aspect of social science that deliberative scholarship has underutilized. To help fill this lacunae, we test our previous findings from an analysis of data from Citizen Initiative Reviews (CIRs) in 2016 by replicating our methodology on data from CIRs in 2018. We set out to determine if the patterns we discovered earlier and developed into the Deliberative Procedures Frame theory appeared again in 2018 CIRs. We find repeating across the two sets of data, including consistent levels of enthusiasm, slow rising happiness, and the relationships between certain emotions on the final day and participants’ evaluations of deliberative quality, and these indicate that our theory remains a viable explanation for emotions in mini-public deliberation. We remain confident that the sources of anger and frustration identified in our previous analysis remains correct. On the basis of this replication, we clarify that what we call the Procedures Frame enables the identification of the most likely time points during deliberation when the threat to democratic legitimacy and the risk to quality deliberation will most likely arise and result in expressions of emotion. Finally, our study reinforces how important deliberative design is to the role of emotions in the success of mini-publics.

2021 ◽  
Jean Alexander ◽  
James A Green

Purpose: This research examined the evidential value of research in Speech, Language, and Hearing (SLH), and the extent to which there is publication bias in reported findings. We also looked at the prevalence of good research practices, including those that work to minimize publication bias.Method: We extracted statistical results from 51 articles reported in four meta-analyses. These were there analyzed with two recent tests for evidential value and publication bias —the p-curve and the Z-curve. These articles were also coded for pre-registration, data access statements, and whether they were replication studies. Results: P-curves were right-skewed indicating evidential value, ruling out selective reporting as the sole reason for the significant findings. The Z-curve similarly found evidential value but detected a relative absence of null results, suggesting there is some publication bias. No studies were pre-registered, no studies had a data access statement, and no studies were full replication studies (3 studies were partial replications).Conclusions: Findings indicate SLH research has evidential value. This means that decision-makers and clinicians can continue to rely on the SLH research evidence base to influence service and clinical decisions. However, the presence of publication bias means that meta-analytic estimates of effectiveness may be exaggerated. Thus, we encourage SLH researchers to engage in study pre-registration, make result data accessible, conduct replication studies, and document null findings.

2021 ◽  
Vol 10 (18) ◽  
pp. 4064
Maria Skibinska ◽  
Pawel Kapelski ◽  
Monika Dmitrzak-Weglarz ◽  
Natalia Lepczynska ◽  
Joanna Pawlak ◽  

Bipolar disorder (BD) is a chronic mental disorder that affects more than 1% of the population worldwide. Over 65% of patients experience early onset of the disease. Most cases of juvenile bipolar disorder begin with a depressed mood episode, and up to 50% of youth initially diagnosed with major depression go onto developing a BD. Our study aimed to find biomarkers of diagnosis conversion in young patients with mood disorders. We performed a two-year follow-up study on 79 adolescent patients diagnosed with MDD or BD, with a detailed clinical assessment at five visits. We monitored diagnosis change from MDD to BD. The control group consisted of 31 healthy youths. According to the neurodevelopmental and neuroimmunological hypotheses of mood disorders, we analyzed serum levels of brain-derived neurotrophic factor (BDNF), proBDNF, epidermal growth factor (EGF), migration inhibitory factor (MIF), stem cell factor (SCF), and correlations with clinical factors. We detected a significant disease-dependent increase in EGF level in MDD and BP patients at baseline exacerbation of depressive or hypomanic/manic episodes as well as in euthymic state compared to healthy controls. No potential biological predictors of disease conversion were found. Replication studies on a larger cohort of patients are needed.

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3085
Pamela A. Koch ◽  
Randi L. Wolf ◽  
Raynika J. Trent ◽  
Ian Yi Han Ang ◽  
Matthew Dallefeld ◽  

Wellness in the Schools (WITS) is a national non-profit organization partnering with public schools to provide healthy, scratch cooked, less processed meals (called an Alternative Menu), and active recess. This study examined the effects of WITS programming on school lunch consumption, including fruit and vegetable intake, in second and third grade students in New York City public schools serving a high proportion of students from low-income households. The intervention was evaluated with a quasi-experimental, controlled design with 14 elementary schools (7 that had initiated WITS programming in fall 2015 and were designated as intervention schools, and 7 matched Control schools). School lunch consumption was assessed by anonymous observation using the System of Observational Cafeteria Assessment of Foods Eaten (SOCAFE) tool in the fall of 2015 (Time 0, early intervention) and the spring of 2016 (Time 1) and 2017 (Time 2). There were no baseline data. Data were also collected on the types of entrées served in the months of October, January, and April during the two school years of the study. Across time points, and relative to students in the Control schools, students in WITS schools ate more fruits and vegetables (units = cups): Time 0: Control 0.18 vs. WITS 0.28; Time 1: Control 0.25 vs. WITS 0.31; and Time 2: Control 0.19 vs. WITS 0.27; p < 0.001. They also had more fruits and vegetables (cups) on their trays, which included more vegetables from the salad bar. However, students in the WITS schools ate fewer entrées (grain and protein) and drank less milk than students in the Control schools. Compared to the Control schools, WITS schools offered more homestyle entrées and fewer finger foods and sandwich entrees, i.e., less processed food. Students in WITS schools who received the Alternative menu and all of the WITS programming at all data collection time points selected and consumed more fruits and vegetables. Replication studies with randomized designs and true baseline data are needed to confirm these findings and to identify avenues for strengthening the effects of the program on other school lunch components.

2021 ◽  
Vol 50 (Supplement_1) ◽  
Thitiya Lukkunaprasit ◽  
Sasivimol Rattanasiri ◽  
Saowalak Turongkaravee ◽  
Atiporn Ingsathit ◽  
John Attia ◽  

Abstract Background Genome-wide association studies showed that rs2231142 (C421A) of ABCG2 gene has strong effects on gout and uric acid (UA). However, replication studies showed conflicting results. We aimed to pool effects of rs2231142 on gout, hyperuricemia, and UA across studies. Methods Studies were located from MEDLINE and Scopus until 17th June 2018. Data extractions were performed by two independent reviewers. Hardy-Weinberg equilibrium was checked. Genotype effects were pooled by ethnicity using mixed-effect logistic model for gout and hyperuricemia and multivariate meta-analysis for UA. Publication bias was assessed using funnel plots and Egger’s tests. Results Thirty studies were eligible; 21, 5, and 8 studies assessed association between rs2231142 and gout, hyperuricemia, and UA, respectively. Carrying AA and CA genotypes were 3.2 (2.4, 4.4) and 1.6 (1.5, 1.8) higher odds to develop gout in Caucasians. Likewise, in Asians, the ORs for corresponding genotypes were 4.5 (4.1, 5.0) and 2.1 (2.0, 2.3) for gout; 2.3 (1.8, 2.8) and 1.6 (1.4, 1.8) for hyperuricemia. Mean differences of UA in Caucasians carrying AA and CA were 50.4 (32.7, 68.2) and 19.5 (14.2, 24.7) µmol/l compared with those carrying CC genotype while in Asians, they were 18.4 (8.7, 28.1) and 11.5 (4.1, 18.9) µmol/l, respectively. Additive gene effects were suggested. Conclusions Significant effects of rs2231142 on gout, hyperuricemia, and elevated UA were confirmed. Our findings should be useful in personalized risk scores for prediction of gout and diseases related to high UA. Key messages rs2231142 increased the risk of gout and UA in Asians and Caucasians

2021 ◽  
Vol 17 (9) ◽  
pp. 20210319
Mariska E. Kret ◽  
Dianne Venneker ◽  
Bronwen Evans ◽  
Iliana Samara ◽  
Disa Sauter

Human adult laughter is characterized by vocal bursts produced predominantly during exhalation, yet apes laugh while exhaling and inhaling. The current study investigated our hypothesis that laughter of human infants changes from laughter similar to that of apes to increasingly resemble that of human adults over early development. We further hypothesized that the more laughter is produced on the exhale, the more positively it is perceived. To test these predictions, novice ( n = 102) and expert (phonetician, n = 15) listeners judged the extent to which human infant laughter ( n = 44) was produced during inhalation or exhalation, and the extent to which they found the laughs pleasant and contagious. Support was found for both hypotheses, which were further confirmed in two pre-registered replication studies. Likely through social learning and the anatomical development of the vocal production system, infants' initial ape-like laughter transforms into laughter similar to that of adult humans over the course of ontogeny.

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