Cortical cross-modal plasticity following deafness measured using functional near-infrared spectroscopy

Evidence from functional neuroimaging studies suggests that the auditory cortex can become more responsive to visual and somatosensory stimulation following deafness, and that this occurs predominately in the right hemisphere. Extensive cross-modal plasticity in prospective cochlear implant recipients is correlated with poor speech outcomes following implantation, highlighting the potential impact of central auditory plasticity on subsequent aural rehabilitation. Conversely, the effects of hearing restoration with a cochlear implant on cortical plasticity are less well understood, since the use of most neuroimaging techniques in CI recipients is either unsafe or problematic due to the electromagnetic artefacts generated by CI stimulation. Additionally, techniques such as functional magnetic resonance imaging (fMRI) are confounded by acoustic noise produced by the scanner that will be perceived more by hearing than by deaf individuals. Subsequently it is conceivable that auditory responses to acoustic noise produced by the MR scanner may mask auditory cortical responses to non-auditory stimulation, and render inter-group comparisons less significant. Uniquely, functional near-infrared spectroscopy (fNIRS) is a silent neuroimaging technique that is non-invasive and completely unaffected by the presence of a CI. Here, we used fNIRS to study temporal-lobe responses to auditory, visual and somatosensory stimuli in thirty profoundly-deaf participants and thirty normally-hearing controls. Compared with silence, acoustic noise stimuli elicited a significant group fNIRS response in the temporal region of normally-hearing individuals, which was not seen in profoundly-deaf participants. Visual motion elicited a larger group response within the right temporal lobe of profoundly-deaf participants, compared with normally-hearing controls. However, bilateral temporal lobe fNIRS activation to somatosensory stimulation was comparable in both groups. Using fNIRS these results confirm that auditory deprivation is associated with cross-modal plasticity of visual inputs to auditory cortex. Although we found no evidence for plasticity of somatosensory inputs, it is possible that our recordings may have included activation of somatosensory cortex that masked any group differences in auditory cortical responses due to the limited spatial resolution associated with fNIRS

Facilitating access to higher education for people seeking asylum in Australia: Institutional and community responses

Higher education remains unattainable for many people seeking asylum in Australia, where temporary visa status renders individuals ineligible for a range of government services including assistance with financing tertiary study. Many universities have responded by offering scholarships and other essential supports; however, our research indicates the challenges associated with studying while living on a temporary visa can affect the success of educational assistance. Here we highlight the importance of scholarships and other supports for facilitating access to tertiary study, particularly given the continuation of restrictive government policies, and identify the need for people seeking asylum to inform institutional and community responses

The F-box protein Cdc4/Fbxw7 is a novel regulator of neural crest development in Xenopus laevis.

BACKGROUND: The neural crest is a unique population of cells that arise in the vertebrate ectoderm at the neural plate border after which they migrate extensively throughout the embryo, giving rise to a wide range of derivatives. A number of proteins involved in neural crest development have dynamic expression patterns, and it is becoming clear that ubiquitin-mediated protein degradation is partly responsible for this. RESULTS: Here we demonstrate a novel role for the F-box protein Cdc4/Fbxw7 in neural crest development. Two isoforms of Xenopus laevis Cdc4 were identified, and designated xCdc4alpha and xCdc4beta. These are highly conserved with vertebrate Cdc4 orthologs, and the Xenopus proteins are functionally equivalent in terms of their ability to degrade Cyclin E, an established vertebrate Cdc4 target. Blocking xCdc4 function specifically inhibited neural crest development at an early stage, prior to expression of c-Myc, Snail2 and Snail. CONCLUSIONS: We demonstrate that Cdc4, an ubiquitin E3 ligase subunit previously identified as targeting primarily cell cycle regulators for proteolysis, has additional roles in control of formation of the neural crest. Hence, we identify Cdc4 as a protein with separable but complementary functions in control of cell proliferation and differentiation

The distribution of satellites around massive galaxies at 1<z<3 in ZFOURGE/CANDELS: dependence on star formation activity

We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1<z<3 using imaging from the FourStar Galaxy Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). The deep near-IR data select satellites down to $\log(M/M_\odot)>9$ at z<3. The radial satellite distribution around centrals is consistent with a projected NFW profile. Massive quiescent centrals, $\log(M/M_\odot)>10.78$, have $\sim$2 times the number of satellites compared to star-forming centrals with a significance of 2.7$\sigma$ even after accounting for differences in the centrals' stellar-mass distributions. We find no statistical difference in the satellite distributions of intermediate-mass quiescent and star-forming centrals, $10.48<\log(M/M_\odot)<10.78$. Comparing to the Guo2011 semi-analytic model, the excess number of satellites indicates that quiescent centrals have halo masses 0.3 dex larger than star-forming centrals, even when the stellar-mass distributions are fixed. We use a simple toy model that relates halo mass and quenching, which roughly reproduces the observed quenched fractions and the differences in halo mass between star-forming and quenched galaxies only if galaxies have a quenching probability that increases with halo mass from $\sim$0 for $\log(M_h/M_\odot)\sim$11 to $\sim$1 for $\log(M_h/M_\odot)\sim$13.5. A single halo-mass quenching threshold is unable to reproduce the quiescent fraction and satellite distribution of centrals. Therefore, while halo quenching may be an important mechanism, it is unlikely to be the only factor driving quenching. It remains unclear why a high fraction of centrals remain star-forming even in relatively massive halos.Comment: 19 pages, 17 figures, accepted by ApJ. Information on ZFOURGE can be found at http://zfourge.tamu.ed

ElrA binding to the 3′UTR of cyclin E1 mRNA requires polyadenylation elements

The early cell divisions of Xenopus laevis and other metazoan embryos occur in the presence of constitutively high levels of the cell cycle regulator cyclin E1. Upon completion of the 12th cell division, a time at which many maternal proteins are downregulated by deadenylation and destabilization of their encoding mRNAs, maternal cyclin E1 protein is downregulated while its mRNA is polyadenylated and stable. We report here that stable polyadenylation of cyclin E1 mRNA requires three cis-acting elements in the 3′ untranslated region; the nuclear polyadenylation sequence, a contiguous cytoplasmic polyadenylation element and an upstream AU-rich element. ElrA, the Xenopus homolog of HuR and a member of the ELAV gene family binds the cyclin E1 3′UTR with high affinity. Deletion of these elements dramatically reduces the affinity of ElrA for the cyclin E1 3′UTR, abolishes polyadenylation and destabilizes the mRNA. Together, these findings provide compelling evidence that ElrA functions in polyadenylation and stabilization of cyclin E1 mRNA via binding these elements

To what extent can behaviour change techniques be identified within an adaptable implementation package for primary care? A prospective directed content analysis

Interpreting evaluations of complex interventions can be difficult without sufficient description of key intervention content. We aimed to develop an implementation package for primary care which could be delivered using typically available resources and could be adapted to target determinants of behaviour for each of four quality indicators: diabetes control, blood pressure control, anticoagulation for atrial fibrillation and risky prescribing. We describe the development and prospective verification of behaviour change techniques (BCTs) embedded within the adaptable implementation packages

Multiple mechanistically distinct modes of endocannabinoid mobilization at central amygdala glutamatergic synapses.

The central amygdala (CeA) is a key structure at the limbic-motor interface regulating stress responses and emotional learning. Endocannabinoid (eCB) signaling is heavily implicated in the regulation of stress-response physiology and emotional learning processes; however, the role of eCBs in the modulation of synaptic efficacy in the CeA is not well understood. Here we describe the subcellular localization of CB1 cannabinoid receptors and eCB synthetic machinery at glutamatergic synapses in the CeA and find that CeA neurons exhibit multiple mechanistically and temporally distinct modes of postsynaptic eCB mobilization. These data identify a prominent role for eCBs in the modulation of excitatory drive to CeA neurons and provide insight into the mechanisms by which eCB signaling and exogenous cannabinoids could regulate stress responses and emotional learning