6,771 research outputs found
Dissolution Arrest and Stability of Armored Bubbles
Dissolving armored bubbles stabilize with nonspherical shapes by jamming the
initially Brownian particles adsorbed on their interfaces. In a gas-saturated
solution, these shapes are characterized by planar facets or folds for
decreasing ratios of the particle to bubble radii. We perform numerical
simulations that mimic dissolution, and show that the faceted shape represents
a local minimum of energy during volume reduction. This minimum is marked by
the vanishing of the Laplace overpressure , which together with the
existence of a -interval where guarantees stability against
dissolution. The reduction of is due to the saddle-shape deformation
of most of the interface which accompanies the reduction in the mean curvature
of the interface.Comment: 5 pages, 3 figures. Submitted to PR
Emotional response inhibition in bipolar disorder: a functional magnetic resonance imaging study of trait- and state-related abnormalities
BACKGROUND:
Impaired response inhibition and poor impulse control are hallmarks of the manic phase of bipolar disorder but are also present during depressive and, to a lesser degree, euthymic periods. The neural mechanisms underlying these impairments are poorly understood, including how mechanisms are related to bipolar trait or state effects.
METHODS:
One-hundred four unmedicated participants with bipolar mania (BM) (n = 30), bipolar depression (BD) (n = 30), bipolar euthymia (BE) (n = 14), and healthy control subjects (n = 30) underwent functional magnetic resonance imaging during emotional and nonemotional go/no-go tasks. The go/no-go task requires participants to press a button for go stimuli, while inhibiting the response to no-go trials. In separate blocks, participants inhibited the response to happy faces, sad faces, or letters.
RESULTS:
The BE group had higher insula activity during happy face inhibition and greater activity in left inferior frontal gyrus during sad face inhibition, demonstrating bipolar trait effects. Relative to the BE group, BD and BM groups demonstrated lower insula activity during inhibition of happy faces, though the depressed sample had lower activity than manic patients. The BD and BM groups had a greater response to inhibiting sad faces in emotion processing and regulation regions, including putamen, insula, and lateral prefrontal cortex. The manic group also had higher activity in insula and putamen during neutral letter inhibition.
CONCLUSIONS:
These results suggest distinct trait- and state-related neural abnormalities during response inhibition in bipolar disorder, with implications for future research and treatment
Machine learning and structural analysis of Mycobacterium tuberculosis pan-genome identifies genetic signatures of antibiotic resistance.
Mycobacterium tuberculosis is a serious human pathogen threat exhibiting complex evolution of antimicrobial resistance (AMR). Accordingly, the many publicly available datasets describing its AMR characteristics demand disparate data-type analyses. Here, we develop a reference strain-agnostic computational platform that uses machine learning approaches, complemented by both genetic interaction analysis and 3D structural mutation-mapping, to identify signatures of AMR evolution to 13 antibiotics. This platform is applied to 1595 sequenced strains to yield four key results. First, a pan-genome analysis shows that M. tuberculosis is highly conserved with sequenced variation concentrated in PE/PPE/PGRS genes. Second, the platform corroborates 33 genes known to confer resistance and identifies 24 new genetic signatures of AMR. Third, 97 epistatic interactions across 10 resistance classes are revealed. Fourth, detailed structural analysis of these genes yields mechanistic bases for their selection. The platform can be used to study other human pathogens
Molecular interaction between natural IgG and ficolin - Mechanistic insights on adaptive-innate immune crosstalk
10.1038/srep03675Scientific Reports
Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen
The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for early dissemination and immune evasion has earned it the designation 'the stealth pathogen'. Despite the many hurdles to studying syphilis pathogenesis, most notably the inability to culture and to genetically manipulate T. pallidum, in recent years, considerable progress has been made in elucidating the structural, physiological, and regulatory facets of T. pallidum pathogenicity. In this Review, we integrate this eclectic body of information to garner fresh insights into the highly successful parasitic lifestyles of the syphilis spirochete and related pathogenic treponemes
Convicts and coolies : rethinking indentured labour in the nineteenth century
This article seeks to shift the frame of analysis within which discussions of Indian indentured migration take place. It argues that colonial discourses and practices of indenture are best understood not with regard to the common historiographical framework of whether it was 'a new system of slavery', but in the context of colonial innovations in incarceration and confinement. The article shows how Indian experiences of and knowledge about transportation overseas to penal settlements informed in important ways both their own understandings and representations of migration and the colonial practices associated with the recruitment of indentured labour. In detailing the connections between two supposedly different labour regimes, it thus brings a further layer of complexity to debates around their supposed distinctions
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