| 1. |
- Schweinsberg, Martin, et al.
(författare)
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Same data, different conclusions : Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis
- 2021
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Ingår i: Organizational Behavior and Human Decision Processes. - : Elsevier BV. - 0749-5978 .- 1095-9920. ; 165, s. 228-249
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Tidskriftsartikel (refereegranskat)abstract
- In this crowdsourced initiative, independent analysts used the same dataset to test two hypotheses regarding the effects of scientists' gender and professional status on verbosity during group meetings. Not only the analytic approach but also the operationalizations of key variables were left unconstrained and up to individual analysts. For instance, analysts could choose to operationalize status as job title, institutional ranking, citation counts, or some combination. To maximize transparency regarding the process by which analytic choices are made, the analysts used a platform we developed called DataExplained to justify both preferred and rejected analytic paths in real time. Analyses lacking sufficient detail, reproducible code, or with statistical errors were excluded, resulting in 29 analyses in the final sample. Researchers reported radically different analyses and dispersed empirical outcomes, in a number of cases obtaining significant effects in opposite directions for the same research question. A Boba multiverse analysis demonstrates that decisions about how to operationalize variables explain variability in outcomes above and beyond statistical choices (e.g., covariates). Subjective researcher decisions play a critical role in driving the reported empirical results, underscoring the need for open data, systematic robustness checks, and transparency regarding both analytic paths taken and not taken. Implications for orga-nizations and leaders, whose decision making relies in part on scientific findings, consulting reports, and internal analyses by data scientists, are discussed.
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| 2. |
- Fassnacht, Martin, et al.
(författare)
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Combination chemotherapy in advanced adrenocortical carcinoma
- 2012
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 366:23, s. 2189-2197
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Adrenocortical carcinoma is a rare cancer that has a poor response to cytotoxic treatment.METHODS:We randomly assigned 304 patients with advanced adrenocortical carcinoma to receive mitotane plus either a combination of etoposide (100 mg per square meter of body-surface area on days 2 to 4), doxorubicin (40 mg per square meter on day 1), and cisplatin (40 mg per square meter on days 3 and 4) (EDP) every 4 weeks or streptozocin (streptozotocin) (1 g on days 1 to 5 in cycle 1; 2 g on day 1 in subsequent cycles) every 3 weeks. Patients with disease progression received the alternative regimen as second-line therapy. The primary end point was overall survival.RESULTS:For first-line therapy, patients in the EDP-mitotane group had a significantly higher response rate than those in the streptozocin-mitotane group (23.2% vs. 9.2%, P<0.001) and longer median progression-free survival (5.0 months vs. 2.1 months; hazard ratio, 0.55; 95% confidence interval [CI], 0.43 to 0.69; P<0.001); there was no significant between-group difference in overall survival (14.8 months and 12.0 months, respectively; hazard ratio, 0.79; 95% CI, 0.61 to 1.02; P=0.07). Among the 185 patients who received the alternative regimen as second-line therapy, the median duration of progression-free survival was 5.6 months in the EDP-mitotane group and 2.2 months in the streptozocin-mitotane group. Patients who did not receive the alternative second-line therapy had better overall survival with first-line EDP plus mitotane (17.1 month) than with streptozocin plus mitotane (4.7 months). Rates of serious adverse events did not differ significantly between treatments.CONCLUSIONS:Rates of response and progression-free survival were significantly better with EDP plus mitotane than with streptozocin plus mitotane as first-line therapy, with similar rates of toxic events, although there was no significant difference in overall survival.
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| 3. |
- Silberzahn, Raphael, et al.
(författare)
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Many analysts, one dataset : Making transparent how variations in analytical choices affect results
- 2018
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Ingår i: Advances in Methods and Practices in Psychological Science. - : Sage Publications. - 2515-2459 .- 2515-2467. ; 1:3, s. 337-356
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-nine teams involving 61 analysts used the same dataset to address the same research question: whether soccer referees are more likely to give red cards to dark skin toned players than light skin toned players. Analytic approaches varied widely across teams, and estimated effect sizes ranged from 0.89 to 2.93 in odds ratio units, with a median of 1.31. Twenty teams (69%) found a statistically significant positive effect and nine teams (31%) observed a non-significant relationship. Overall 29 differentanalyses used 21 unique combinations of covariates. We found that neither analysts' prior beliefs about the effect, nor their level of expertise, nor peer-reviewed quality of analysis readily explained variation in analysis outcomes. This suggests that significant variation in the results of analyses of complex data may be difficult to avoid, even by experts with honest intentions. Crowdsourcing data analysis, a strategy by which numerous research teams are recruited to simultaneously investigate the same research question, makes transparent how defensible, yet subjective analytic choices influence research results.
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| 4. |
- Anderson, Christopher J., et al.
(författare)
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Response to Comment on "Estimating the reproducibility of psychological science"
- 2016
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 351:6277
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Gilbert et al. conclude that evidence from the Open Science Collaboration's Reproducibility Project: Psychology indicates high reproducibility, given the study methodology. Their very optimistic assessment is limited by statistical misconceptions and by causal inferences from selectively interpreted, correlational data. Using the Reproducibility Project: Psychology data, both optimistic and pessimistic conclusions about reproducibility are possible, and neither are yet warranted.
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| 5. |
- Coufalova, Eva, et al.
(författare)
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Low Voltage Mini TEM
- 2014
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Ingår i: Proceedings.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Demchyshyn, Stepan, et al.
(författare)
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Confining metal-halide perovskites in nanoporous thin films
- 2017
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Ingår i: Science Advances. - : AMER ASSOC ADVANCEMENT SCIENCE. - 2375-2548. ; 3:8
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Tidskriftsartikel (refereegranskat)abstract
- Controlling the size and shape of semiconducting nanocrystals advances nanoelectronics and photonics. Quantumconfined, inexpensive, solution-derived metal halide perovskites offer narrowband, color-pure emitters as integral parts of next-generation displays and optoelectronic devices. We use nanoporous silicon and alumina thin films as templates for the growth of perovskite nanocrystallites directly within device-relevant architectures without the use of colloidal stabilization. We find significantly blue-shifted photoluminescence emission by reducing the pore size; normally infrared-emitting materials become visibly red, and green-emitting materials become cyan and blue. Confining perovskite nanocrystals within porous oxide thin films drastically increases photoluminescence stability because the templates auspiciously serve as encapsulation. We quantify the template-induced size of the perovskite crystals in nanoporous silicon with microfocus high-energy x-ray depth profiling in transmission geometry, verifying the growth of perovskite nanocrystals throughout the entire thickness of the nanoporous films. Low-voltage electroluminescent diodes with narrow, blue-shifted emission fabricated from nanocrystalline perovskites grown in embedded nanoporous alumina thin films substantiate our general concept for next-generation photonic devices.
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| 7. |
- Goderis, Steven, et al.
(författare)
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Globally distributed iridium layer preserved within the Chicxulub impact structure
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- The Cretaceous-Paleogene (K-Pg) mass extinction is marked globally by elevated concentrations of iridium, emplaced by a hypervelocity impact event 66 million years ago. Here, we report new data from four independent laboratories that reveal a positive iridium anomaly within the peak-ring sequence of the Chicxulub impact structure, in drill core recovered by IODP-ICDP Expedition 364. The highest concentration of ultrafine meteoritic matter occurs in the post-impact sediments that cover the crater peak ring, just below the lowermost Danian pelagic limestone. Within years to decades after the impact event, this part of the Chicxulub impact basin returned to a relatively low-energy depositional environment, recording in unprecedented detail the recovery of life during the succeeding millennia. The iridium layer provides a key temporal horizon precisely linking Chicxulub to K-Pg boundary sections worldwide.
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| 8. |
- Hubicka, Zdenek, et al.
(författare)
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Reactive sputtering of Fe2O3 thin films by high power pulsed plasma systems
- 2012
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Konferensbidrag (refereegranskat)abstract
- Semiconductor oxide thin films of Fe2O3 were deposited by reactive sputtering in a high power pulse magnetron and in a pulsed hollow cathode plasma jet sputtering system. Properties of deposited Fe2O3 were investigated for photocatalytic water splitting applications. Fe2O3 provide a potential to capture a relatively significant portion of the available solar light due to lower band-gap energies. The first system used in this study was the high power pulsed magnetron sputtering system (HIPIMS) employing metallic target of pure iron with outer diameter 50 mm and working in a gas mixture of Ar and O2. Influence of different magnitudes of the applied pulsed power and pulsing frequency on the formation of crystalline structure, physical properties and photocatalytical properties was investigated. The maximum pulsed current density used in our reactive HIPIMS magnetron system was ≈ 5 A/cm2. Oxide Fe2O3 thin films were deposited also by a low pressure DC pulsed hollow cathode system. The metallic hollow cathode with internal diameter 5 mm and length 30 mm was sputtered in argon plasma flow and reactive gas oxygen was supplied directly to the reactor. The hollow cathode discharge was supplied from the DC pulsed power supplier working in high power pulsed mode. The maximum attained pulsed current density in our hollow cathode discharge was approximately ≈ 3 A/cm2. The main advantage of this system was the high deposition rate which was nearly independent on the amount of used oxygen in the plasma. A plasma diagnostics was carried out in all the investigated systems. The most important was measurement with various forms of quartz crystal microbalance QCM with several types systems of grids. These systems were used to determine ionization fraction of sputtered and reactively sputtered particle fluxes to the substrate under different deposition conditions of these oxide thin films. The higher ionization fraction of sputtered particles was found for higher current densities in the pulse. In the HIPIMS magnetron, the maximum of ionization fraction of reactively sputtered particles was found around ≈ 60-70% for 5% duty cycle of pulsing frequency. The maximum ionization fraction of sputtered particles in the reactive pulsed hollow cathode system was usually lower than in the investigated reactive HIPIMS magnetron system.
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| 9. |
- Kacerovsky, Marian, et al.
(författare)
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Amniotic fluid glucose level in PPROM pregnancies: a glance at the old friend.
- 2020
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Ingår i: The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. - : Informa UK Limited. - 1476-4954. ; 35:12, s. 2247-2259
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: To determine the amniotic fluid glucose levels in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) based on the presence of microbial invasion of the amniotic cavity and/or intra-amniotic inflammation.Methods of Study: A total of 142 women with singleton pregnancies complicated by PPROM between gestational ages 24+0 and 36+6weeks were included. Amniocentesis was performed at the time of admission. The assessments of microbial invasion of the amniotic cavity (using both cultivation and non-cultivation techniques) and intra-amniotic inflammation (amniotic fluid interleukin-6 levels ≥ 3000pg/mL) were performed on all the women. Based on the presence of microbial invasion of the amniotic cavity and/or intra-amniotic inflammation, the women were further categorized into the subgroups: (i) intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation); (ii) sterile intra-amniotic inflammation (the presence of intra-amniotic inflammation without microbial invasion of the amniotic cavity); (iii) colonization (the presence of microbial invasion of the amniotic cavity without intra-amniotic inflammation); and (iv) negative amniotic fluid (the absence of either microbial invasion of the amniotic cavity or intra-amniotic inflammation). Amniotic fluid glucose levels were assessed using enzymatic reference method with hexokinase.Results: There was a difference in the amniotic fluid glucose levels among the women with intra-amniotic infection, sterile intra-amniotic inflammation, colonization, and those with negative amniotic fluid (p<.0001). No difference was found in the amniotic fluid glucose levels between women with intra-amniotic infection and those with sterile intra-amniotic inflammation [infection: median 11.6mg/dL (0.7mmol/L) vs. sterile: median 6.3mg/dL (0.4mmol/L); p=.41] and between women with colonization and negative amniotic fluid [colonization: median 21.6mg/dL (1.2mmol/L) vs. negative: median 23.4mg/dL (1.3mmol/L; p=.67]. Women with intra-amniotic infection and sterile intra-amniotic inflammation had lower amniotic fluid glucose levels than women with colonization and with negative amniotic fluid in crude analysis as well as after adjustment for gestational age at sampling. Amniotic fluid glucose level of 10mg/dL (0.56mmol/L) was the optimal concentration for the identification of intra-amniotic inflammation in women with PPROM.Conclusions: The presence of intra-amniotic inflammation was associated with lower amniotic fluid glucose levels in singleton pregnancies complicated with PPROM. An amniotic fluid glucose level of 10mg/dL (0.56mmol/L) was the optimal concentration for the identification of intra-amniotic inflammation in PPROM pregnancies. In the absence of better amniotic fluid markers, amniotic glucose could be used as a marker of intra-amniotic inflammation, with very good specificity in PPROM pregnancies.
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| 10. |
- Kacerovsky, Marian, et al.
(författare)
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Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes.
- 2020
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Ingår i: American journal of obstetrics and gynecology. - : Elsevier BV. - 1097-6868 .- 0002-9378. ; 223:1
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Tidskriftsartikel (refereegranskat)abstract
- Preterm prelabor rupture of the membranes (PPROM) is frequently complicated by intraamniotic inflammatory processes such as intraamniotic infection and sterile intraamniotic inflammation. Antibiotic therapy is recommended to patients with PPROM to prolong the interval between this complication and delivery (latency period), reduce the risk of clinical chorioamnionitis, and improve neonatal outcome. However, there is a lack of information regarding whether the administration of antibiotics can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with PPROM.The first aim of the study was to determine whether antimicrobial agents can reduce the magnitude of the intraamniotic inflammatory response in patients with PPROM by assessing the concentrations of interleukin-6 in amniotic fluid before and after antibiotic treatment. The second aim was to determine whether treatment with intravenous clarithromycin changes the microbial load of Ureaplasma spp DNA in amniotic fluid.A retrospective cohort study included patients who had (1) a singleton gestation, (2) PPROM between 24+0 and 33+6 weeks, (3) a transabdominal amniocentesis at the time of admission, and (4) intravenous antibiotic treatment (clarithromycin for patients with intraamniotic inflammation and benzylpenicillin/clindamycin in the cases of allergy in patients without intraamniotic inflammation) for 7 days. Follow-up amniocenteses (7th day after admission) were performed in the subset of patients with a latency period lasting longer than 7 days. Concentrations of interleukin-6 were measured in the samples of amniotic fluid with a bedside test, and the presence of microbial invasion of the amniotic cavity was assessed with culture and molecular microbiological methods. Intraamniotic inflammation was defined as a bedside interleukin-6 concentration ≥745 pg/mL in the samples of amniotic fluid. Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presenceof intraamniotic inflammation without microbial invasion of the amniotic cavity.A total of 270 patients with PPROM were included in this study: 207 patients delivered within 7 days and 63 patients delivered after 7 days of admission. Of the 63 patients who delivered after 7 days following the initial amniocentesis, 40 underwent a follow-up amniocentesis. Patients with intraamniotic infection (n= 7) and sterile intraamniotic inflammation (n= 7) were treated with intravenous clarithromycin. Patients without either microbial invasion of the amniotic cavity or intraamniotic inflammation (n= 26) were treated with benzylpenicillin or clindamycin. Treatment with clarithromycin decreased the interleukin-6 concentration in amniotic fluid at the follow-up amniocentesis compared to the initial amniocentesis in patients with intraamniotic infection (follow-up: median, 295 pg/mL, interquartile range [IQR], 72-673 vs initial: median, 2973 pg/mL, IQR, 1750-6296; P= .02) and in those with sterile intraamniotic inflammation (follow-up: median, 221 pg/mL, IQR 118-366 pg/mL vs initial: median, 1446 pg/mL, IQR, 1300-2941; P= .02). Samples of amniotic fluid with Ureaplasma spp DNA had a lower microbial load at the time offollow-up amniocentesis compared to the initial amniocentesis (follow-up: median, 1.8× 104 copies DNA/mL, 2.9× 104 to 6.7× 108 vs initial: median, 4.7× 107 copies DNA/mL, interquartile range, 2.9× 103 to 3.6× 107; P= .03).Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation. Moreover, treatment with clarithromycin was related to a reduction in the load of Ureaplasma spp DNA in the amniotic fluid of patients with PPROM <34 weeks of gestation.
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