Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes

Influence of Patterning in the Acid–Base Interfacial Properties of Homogeneously Mixed CH3- and COOH-Terminated Self-Assembled Monolayers

The acid/base interfacial behavior of mixed self-assembled monolayers (SAMs) of 1-decanethiol (DT) and 11-mercaptoundecanoic acid (MUA) formed on gold from a micellar medium has been characterized by electrochemical impedance spectroscopy (EIS) and infrared reflection-absorption spectroscopy (IRRAS) titration experiments as a function of their surface composition. The surface composition is determined from the interfacial capacitance of the SAMs that behave as a dielectric medium of the expected thickness for well-organized layers. The interaction parameter and the apparent and the intrinsic surface pKa values of these pH-responsive SAMs are obtained by fitting the EIS and IR titration curves to the 1-pK model. The shift in the surface pKa while decreasing the MUA surface fraction resembles the behavior of homogeneously mixed systems. The trends observed can be explained by the lowering of intermolecular in-plane repulsive interactions between neighboring MUA molecules and by the local solvation and hydrophobic effects when the MUA domains decrease below a critical size and the terminal groups are probably titrated at domain boundaries, small arrangements, or even isolated. The transition between both scenarios and the formation of hydrogen bonding interactions upon a structural reorganization are conditioned by the heterogeneity in the size distribution of MUA and DT molecular domains which depends on the formation conditions of the SAMs. All together it is demonstrated to play a role in the acid/base properties of these monolayers which has a direct implication in the proper design of interfacial devices based on organic molecular junctions or biomolecular assemblies

Time spent in retirement, health and well-being

IntroductionFrom a life-span developmental perspective, retirement can be considered a life event that entails a complex psychological challenge, including leaving one's professional life and organizing/enjoying the newly available free time. The literature about retirement identifies different stages and patterns of transition/adaption associated with time spent in retirement.ObjectivesTo analyze the association between time spent in retirement and subjective measures of mental health, depressive symptomatology, loneliness and satisfaction with life.MethodsQuantitative cross-sectional study with 641 participants (M = 74,86). The instruments included: sociodemographic questionnaire; mental health inventory (MHI-5); geriatric depression scale (GDS); UCLA loneliness scale; satisfaction with life scale (SWLS).ResultsStatistically significant differences in all the health and well-being variables addressed were found between subgroups of time spent in retirement (MHI-5: P = 0.001; GDS: P &lt; 0.001; UCLA: P = 0.038; SWLS: P = 0.022). Mental health and satisfaction with life increases in the first year after retirement, but during the second year, they decrease to the levels found in pre-retirement. Loneliness and depressive symptomatology follow an inverted pattern. With the passing of years, loneliness and depression tend to increase; mental health and satisfaction with life tend to decrease.ConclusionsThe results provide support to the hypotheses of honeymoon and disenchantment phases in the recently retired and to the existence of different patterns of transition/adaptation associated with time spent in retirement. They also highlight the relevance of devising intervention strategies that enable individuals to maintain the satisfaction levels with life and mental health achieved during the first phase of retirement.Disclosure of interestThe authors have not supplied their declaration of competing interest.</jats:sec

Pre-menstrual syndrome and pyridoxine. A therapeutic alternative? [SINDROME PREMENSTRUAL Y PIRIDOXINA: ALTERNATIVA TERAPEUTICA?]

[No abstract available