Suppressing sensorimotor activity modulates the discrimination of auditory emotions but not speaker identity

Our ability to recognize the emotions of others is a crucial feature of human social cognition. Functional neuroimaging studies indicate that activity in sensorimotor cortices is evoked during the perception of emotion. In the visual domain, right somatosensory cortex activity has been shown to be critical for facial emotion recognition. However, the importance of sensorimotor representations in modalities outside of vision remains unknown. Here we use continuous theta-burst transcranial magnetic stimulation (cTBS) to investigate whether neural activity in the right postcentral gyrus (rPoG) and right lateral premotor cortex (rPM) is involved in nonverbal auditory emotion recognition. Three groups of participants completed same-different tasks on auditory stimuli, discriminating between the emotion expressed and the speakers' identities, before and following cTBS targeted at rPoG, rPM, or the vertex (control site). A task-selective deficit in auditory emotion discrimination was observed. Stimulation to rPoG and rPM resulted in a disruption of participants' abilities to discriminate emotion, but not identity, from vocal signals. These findings suggest that sensorimotor activity may be a modality-independent mechanism which aids emotion discrimination. Copyright © 2010 the authors

Dynamics of photo-induced ferromagnetism in oxides with orbital degeneracy

By using intense coherent electromagnetic radiation, it may be possible to manipulate the properties of quantum materials very quickly, or even induce new and potentially useful phases that are absent in equilibrium. For instance, ultrafast control of magnetic dynamics is crucial for a number of proposed spintronic devices and can also shed light on the possible dynamics of correlated phases out of equilibrium. Inspired by recent experiments on spin-orbital ferromagnet YTiO3 we consider the nonequilibrium dynamics of Heisenberg ferromagnetic insulator with low-lying orbital excitations. We model the dynamics of the magnon excitations in this system following an optical pulse which resonantly excites infrared-active phonon modes. As the phonons ring down they can dynamically couple the orbitals with the low-lying magnons, leading to a dramatically modified effective bath for the magnons. We show this transient coupling can lead to a dynamical acceleration of the magnetization dynamics, which is otherwise bottlenecked by small anisotropy. Exploring the parameter space more we find that the magnon dynamics can also even completely reverse, leading to a negative relaxation rate when the pump is blue-detuned with respect to the orbital bath resonance. We therefore show that by using specially targeted optical pulses, one can exert a much greater degree of control over the magnetization dynamics, allowing one to optically steer magnetic order in this system. We conclude by discussing interesting parallels between the magnetization dynamics we find here and recent experiments on photo-induced superconductivity, where it is similarly observed that depending on the initial pump frequency, an apparent metastable superconducting phase emerges

The Relationship between Arthritis and Muscular Strength in Older Women with Symptoms of Sarcopenia

Background: Sarcopenia classification is important for prevention or intervention of sarcopenia in the elderly. However, measures used for the current sarcopenia criteria, including muscular strength, could be impacted by forms of arthritis. Thus, it is crucial to understand the impact arthritis has on sarcopenia status. Objectives: The aim was to investigate if arthritis relates to sarcopenia classification via grip strength or single chair stand in older women. A secondary aim was to assess the relationship between grip strength and upper and lower body strength in those with arthritis. Design: A cross-sectional analysis. Setting and participants: Sixty-one community-dwelling older women (71.9±4.6 years) from Rhode Island. Measurements: Sarcopenia status was classified using established working definitions. Grip strength was measured using a hand grip dynamometer, chair stands were measured via a single chair stand test, and gait speed was assessed using a four-meter walk test. A segmental multifrequency bioelectrical impedance analysis assessed body composition and arthritis status was based on self-report. Upper and lower body muscular strength were measured using a chest press and leg press one repetition maximum. Results: No associations were observed between arthritis and sarcopenia status (p=0.36) nor arthritis and upper or lower body muscular strength and grip strength. Conclusions: The results of this study may indicate that arthritis is not associated with sarcopenia status but may affect other measures of muscular strength

Objectively measured physical activity is associated with dorsolateralprefrontal cortex volume in older adults

Background: Epidemiological studies suggest physical activity (PA) can slow or prevent both cognitive decline and age-related atrophy in frontal and hippocampal gray matter volumes. However, much of this evidence is based on self-reported measures of PA. Methods: PA was measured objectively with a SenseWear™ Armband to examine the cross-sectional associations between the duration of light, moderate and vigorous intensity PA with gray matter volume in the dorsolateral prefrontal cortex (DLPFC) and hippocampus in 167 (female: 43%) cognitively healthy older adults aged 73 to 78. Results: The duration of objective moderate to vigorous intensity physical activity (MVPA) was associated with a greater volume of the right DLPFC (β ​= ​0.16; p ​= ​0.04). In addition, objective moderate-intensity PA alone was also associated with greater volume of the left (β ​= ​0.17; p ​= ​0.03) and right (β ​= ​0.19; p ​= ​0.01) DLPFC after controlling for covariates and adjustment for multiple comparisons. In contrast, there were no significant associations between light- or vigorous-intensity PA and gray matter volumes (all p ​> ​0.05). No associations between PA and cognitive performance were detected, and self-reported PA was not associated with any of the outcomes investigated. Conclusions: These findings suggest that an intensity-dependent relationship may exist, whereby a greater duration of MVPA, perhaps driven by moderate-intensity PA, is associated with preserved gray matter volume in frontal regions of the brain. Future research should investigate the mechanisms of this dose-effect and determine whether greater brain volumes associated with objective PA convey protective effects against cognitive decline

Comparison of Current Sarcopenia Classification Criteria in Older New England Women

Objectives: To evaluate the prevalence of sarcopenia in a sample of older, sedentary women using criteria from the European Working Group on Sarcopenia in Older People (EWGSOP), the International Working Group (IWG), and the Foundation for the National Institutes of Health Sarcopenia Project (FNIHSP). Design: Cross-sectional analysis. Setting and Participants: Community-dwelling women (n = 61) aged 71.9 ± 4.6 years (mean±SD) with a BMI 27.3 ± 6.0 kg/m2 who by self-report were healthy and did not exercise were recruited and evaluated for sarcopenia. Measurements: Height, weight, grip strength, gait speed, and appendicular lean mass (via segmental multi-frequency bioelectrical impedance analysis: SMF-BIA) were measured. Prevalence was reported using descriptive statistics and a Fisher’s exact test was used to analyze the distribution frequency of sarcopenia classification by different criteria. Results: In this sample 14.8% met EWGSOP criteria, 6.6% met FNIHSP criteria, and 3.3% met IWG criteria. There was a borderline significant difference in distribution frequency between EWGSOP and IWG classification criteria (p=0.053). Conclusion: The variation in sarcopenia prevalence depending on the diagnostic criteria used is consistent with previous research and there are borderline significant differences between classification criteria in this population. These data suggest the need for additional examination to determine current cut points for ALM measured by SMF-BIA, as well as which established definition of sarcopenia is appropriate for this population

Genetic evidence for SecY translocon-mediated import of two 3 contact-dependent growth inhibition (CDI) toxins

The C-terminal (CT) toxin domains of contact-dependent growth inhibition (CDI) CdiA proteins target Gram-negative bacteria and must breach both the outer and inner membranes of target cells to exert growth inhibitory activity. Here, we examine two CdiA-CT toxins that exploit the bacterial general protein secretion machinery after delivery into the periplasm. A Ser281Phe amino acid substitution in transmembrane segment 7 of SecY, the universally conserved channel-forming subunit of the Sec translocon, decreases the cytotoxicity of the membrane depolarizing orphan10 toxin from enterohemorrhagic Escherichia coli EC869. Target cells expressing secY(S281F) and lacking either PpiD or YfgM, two SecY auxiliary factors, are fully protected from CDI-mediated inhibition either by CdiA-CTo10EC869 or by CdiA-CTGN05224, the latter being an EndoU RNase CdiA toxin from Klebsiella aerogenes GN05224 that has a related cytoplasm entry domain. RNase activity of CdiA-CTGN05224 was reduced in secY(S281F) target cells and absent in secY(S281F) Delta ppiD or secY(S281F) Delta yfgM target cells during competition co-cultures. Importantly, an allele-specific mutation in secY (secY(G313W)) renders DppiD or Delta yfgM target cells specifically resistant to CdiA-CTGN05224 but not to CdiA-CTo10EC869, further suggesting a direct interaction between SecY and the CDI toxins. Our results provide genetic evidence of a unique confluence between the primary cellular export route for unfolded polypeptides and the import pathways of two CDI toxins. IMPORTANCE Many bacterial species interact via direct cell-to-cell contact using CDI systems, which provide a mechanism to inject toxins that inhibit bacterial growth into one another. Here, we find that two CDI toxins, one that depolarizes membranes and another that degrades RNA, exploit the universally conserved SecY translocon machinery used to export proteins for target cell entry. Mutations in genes coding for members of the Sec translocon render cells resistant to these CDI toxins by blocking their movement into and through target cell membranes. This work lays the foundation for understanding how CDI toxins interact with the protein export machinery and has direct relevance to development of new antibiotics that can penetrate bacterial cell envelopes