800 research outputs found
Abandon Statistical Significance
We discuss problems the null hypothesis significance testing (NHST) paradigm
poses for replication and more broadly in the biomedical and social sciences as
well as how these problems remain unresolved by proposals involving modified
p-value thresholds, confidence intervals, and Bayes factors. We then discuss
our own proposal, which is to abandon statistical significance. We recommend
dropping the NHST paradigm--and the p-value thresholds intrinsic to it--as the
default statistical paradigm for research, publication, and discovery in the
biomedical and social sciences. Specifically, we propose that the p-value be
demoted from its threshold screening role and instead, treated continuously, be
considered along with currently subordinate factors (e.g., related prior
evidence, plausibility of mechanism, study design and data quality, real world
costs and benefits, novelty of finding, and other factors that vary by research
domain) as just one among many pieces of evidence. We have no desire to "ban"
p-values or other purely statistical measures. Rather, we believe that such
measures should not be thresholded and that, thresholded or not, they should
not take priority over the currently subordinate factors. We also argue that it
seldom makes sense to calibrate evidence as a function of p-values or other
purely statistical measures. We offer recommendations for how our proposal can
be implemented in the scientific publication process as well as in statistical
decision making more broadly
Evidence of Low-Temperature Superparamagnetism in Mn_{4}$ Nanoparticle Ensembles
Please refer to the abstract within the main body of the paper
Lessons Learned from a Summer Melt Prevention Program
The overarching goal of CACAN is to increase college enrollment, with an emphasis on closing the existing gap between economically disadvantaged and non-economically disadvantaged students. The pilot of the summer melt prevention program accomplished that. Students who participated in the program were 1.4 times more likely to go to college the fall after high school graduation when compared to the matched comparison group and 3.4 times more likely to go when compared to students who disengaged from the program
Evidence of a biodiversity crisis documented on a peritidal carbonate succession from western Tethys (Sicily): new data on the End Triassic Mass Extinction
A biodiversity crisis was observed in the latest Triassic on both macro-and micro-benthic communities from a western Tethyan carbonate platform. The studied succession represented by the Monte Sparagio section consists of a continuous Upper Triassic to Lower Jurassic peritidal limestones organized in shallowing upward cycles. The subtidal facies in the lower part of this section (Unit A) contains very abundant and highly diverse fossiliferous assemblages consisting of very large megalodontoids (up to 40 cm). Up-section, a reduction of biodiversity, abundance and shell size of megalodontoids (up to 15 cm) tipifies Unit B. Similarly, in this last Unit, the average dimensions of the benthic foraminifer T. hantkeni decreases (ca. 30%). After a short interval marked by a bloom of the problematic alga T. parvovesiculifera, the overlying Unit C accounts for the recovery of the Jurassic benthic community. The geochemical analyses of stable isotopes (C, O and S) seem correlative to the drastic reduction in the Rhaetian biodiversity between Unit A and Unit B. These biodiversity crises in the Rhaetian horizons can be interpreted as a precursor of the End Triassic Extinction and provide new insights into the existence of two extinction pulses at the end of Triassic. These data are in accordance with the environmental parameters of survival in a modern tropical shallow water platform (T-factory). In particular, the sea surface temperature (SST) of a T-factory ranges from 18 degrees C to 30.5 degrees C representing respectively the minimum SST for the carbonate factory persistence and the maximum SST that a T-factory can tolerate
Recent Improvements to CALIOP Level 3 Aerosol Profile Product for Global 3-D Aerosol Extinction Characterization
No abstract availabl
Magnetodielectric coupling in Mn3O4
We have investigated the dielectric anomalies associated with spin ordering
transitions in the tetragonal spinel MnO, using thermodynamic,
magnetic, and dielectric measurements. We find that two of the three magnetic
ordering transitions in MnO lead to decreases in the temperature
dependent dielectric constant at zero applied field. Applying a magnetic field
to the polycrystalline sample leaves these two dielectric anomalies practically
unchanged, but leads to an increase in the dielectric constant at the
intermediate spin-ordering transition. We discuss possible origins for this
magnetodielectric behavior in terms of spin-phonon coupling. Band structure
calculations suggest that in its ferrimagnetic state, MnO corresponds
to a semiconductor with no orbital degeneracy due to strong Jahn-Teller
distortion.Comment: 6 pages, 7 figure
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