A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect

We conducted a preregistered multilaboratory project (k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result (d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect (d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation.

Perceiving demographic diversity as a threat: Divergent effects of multiculturalism and polyculturalism

The growing racial/ethnic diversity in the United States can be perceived as threatening to White Americans. The present work examines how interethnic ideologies—different ways of framing ethnic diversity—moderate perceptions of threat and political conservatism among White Americans exposed to a passage about the US becoming a “majority-minority” nation. Across 3 studies, we found divergent effects of multiculturalism and polyculturalism within the context of growing diversity. Priming multiculturalism increased perceived threats to the ingroup’s power and status, which in turn led to greater endorsement of conservative political views (Studies 1 and 3) and warmer feelings toward a conservative political figure (i.e., Donald Trump; Studies 2 and 3); however, these relationships were attenuated and sometimes reversed among participants primed with polyculturalism. We discuss implications for how interethnic ideologies influence White Americans’ threatened responses to increasing diversity.

Impact of 5-HTTLPR on hippocampal subregional activation in older adults

Studies have shown that a functional polymorphism of the serotonin transporter gene (5-HTTLPR) impacts performance on memory-related tasks and the hippocampal structures that subserve these tasks. The short (s) allele of 5-HTTLPR has been linked to greater susceptibility for impaired memory and smaller hippocampal volume compared to the long allele (l). However, previous studies have not examined the associations between 5-HTTLPR allele and activation in subregions of the hippocampus. In this study, we used functional magnetic resonance imaging (fMRI) to measure activation in hippocampal and temporal lobe subregions in 36 elderly non-clinical participants performing a face-name encoding and recognition task. Although there were no significant differences in task performance between s allele carriers and l homozygotes, right CA1 and right parahippocampal activation during recognition errors was significantly greater in individuals bearing the s allele. In an exploratory analysis, we determined that these effects were more pronounced in s allele carriers with the apolipoprotein ɛ4 allele. Our results suggest that older individuals with the s allele inefficiently allocate neural resources while making errors in recognizing face-name associations, which could negatively impact memory performance during more challenging tasks.

Reconstruction of the transected cat spinal cord following NeuroGel implantation: axonal tracing, immunohistochemical and ultrastructural studies

This study examined the ability of NeuroGel, a biocompatible porous poly [N-(2-hydroxypropyl) methacrylamide] hydrogel, to establish a permissive environment across a 3 mm gap in the cat spinal cord in order to promote tissue reconstitution and axonal regeneration across the lesion. Animals with NeuroGel implants were compared to transection-only controls and observed for 21 months. The hydrogel formed a stable bridge between the cord segments. Six months after reconstructive surgery, it was densely infiltrated by a reparative tissue composed of glial cells, capillary vessels and axonal fibres. Axonal labelling and double immunostaining for neurofilaments and myelin basic protein, showed that descending supraspinal axons of the ventral funiculus and afferent fibres of the dorsal column regenerated across the reconstructed lesion. Fifteen months after reconstructive surgery, axons had grown, at least, 12 mm into the distal cord tissue, and in the rostral cord there was labelling of neurons of the intermediate gray matter. Electron microscopy showed that after 9 months, most of the regenerating axons were myelinated, principally by Schwann cells. Newly formed neurons presumably from precursor cells of the ependyma and/or migrating neurons were observed within the reparative tissue after 21 months. Results indicate that functional deficit, as assessed by treadmill training, and morphological changes following double transection of the spinal cord can be modified by the implantation of NeuroGel. This technology offers the potential to promote the formation of a neural tissue equivalent via a reparative neohistogenesis process, that facilitates and supports regenerative growth of axons.

[Histoplasmosis of the central nervous system. Report of 2 cases and review of the literature]

The involvement of the central nervous system by histoplasma is an infrequent complication. The clinical diagnosis is difficult because the microscopic examination and the culture of the spinal fluid are frequently negative. In this article we report two cases of meningitis by Histoplasma capsulatum in patients with acquired immunodeficiency syndrome. The first case is a meningitis without evidence of disseminated histoplasmosis in a patient who had been treated with amphotericin B. The histologic appearance was that of a granulomatous inflammation of the meninges and the underlying nervous tissue. The second case is a disseminated histoplasmosis with involvement of the central nervous system. This consists of macrophages filled with histoplasma invading the meninges and underlying nervous tissue without associated inflammation.

Tension fecal pneumothorax in a postpartum patient

A 20-year-old woman developed severe shortness of breath 4 h after a cesarean section. Chest roentgenogram showed a pleural effusion and tension pneumothorax; insertion of a chest tube drained liquid stool. At surgery she was found to have a left diaphragmatic defect with herniation, strangulation, and perforation of the transverse colon into the pleural cavity.