67 research outputs found

    Sensorimotor Modulations by Cognitive Processes During Accurate Speech Discrimination: An EEG Investigation of Dorsal Stream Processing

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    Internal models mediate the transmission of information between anterior and posterior regions of the dorsal stream in support of speech perception, though it remains unclear how this mechanism responds to cognitive processes in service of task demands. The purpose of the current study was to identify the influences of attention and working memory on sensorimotor activity across the dorsal stream during speech discrimination, with set size and signal clarity employed to modulate stimulus predictability and the time course of increased task demands, respectively. Independent Component Analysis of 64–channel EEG data identified bilateral sensorimotor mu and auditory alpha components from a cohort of 42 participants, indexing activity from anterior (mu) and posterior (auditory) aspects of the dorsal stream. Time frequency (ERSP) analysis evaluated task-related changes in focal activation patterns with phase coherence measures employed to track patterns of information flow across the dorsal stream. ERSP decomposition of mu clusters revealed event-related desynchronization (ERD) in beta and alpha bands, which were interpreted as evidence of forward (beta) and inverse (alpha) internal modeling across the time course of perception events. Stronger pre-stimulus mu alpha ERD in small set discrimination tasks was interpreted as more efficient attentional allocation due to the reduced sensory search space enabled by predictable stimuli. Mu-alpha and mu-beta ERD in peri- and post-stimulus periods were interpreted within the framework of Analysis by Synthesis as evidence of working memory activity for stimulus processing and maintenance, with weaker activity in degraded conditions suggesting that covert rehearsal mechanisms are sensitive to the quality of the stimulus being retained in working memory. Similar ERSP patterns across conditions despite the differences in stimulus predictability and clarity, suggest that subjects may have adapted to tasks. In light of this, future studies of sensorimotor processing should consider the ecological validity of the tasks employed, as well as the larger cognitive environment in which tasks are performed. The absence of interpretable patterns of mu-auditory coherence modulation across the time course of speech discrimination highlights the need for more sensitive analyses to probe dorsal stream connectivity

    Elite City-Deals For Economic Growth? Cardiff Capital Region, Devolution and the Positioning of Civil Society Actors

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    The concept of localism and spatial delineation of the ‘city region’ have seen a renaissance as the de facto spatial political units of governance for economic development. One articulation of this has seen the creation of Cardiff Capital Region (CCR) to potentially enhance Wales’s poor economic performance and secure democratic forms of social cohesion. City regions have been vaunted as the ‘spatial imaginary’ for engendering economic development, but there are considerable state spatial restructuring tensions. The paper discusses these by following the development of city-regionalism in Wales and specifically the unfolding of the ‘elite-led’ CCR City-Deal

    The insect, Galleria mellonella, is a compatible model for evaluating the toxicology of okadaic acid

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    The polyether toxin, okadaic acid, causes diarrhetic shellfish poisoning in humans. Despite extensive research into its cellular targets using rodent models, we know little about its putative effect(s) on innate immunity. We inoculated larvae of the greater waxmoth, Galleria mellonella, with physiologically relevant doses of okadaic acid by direct injection into the haemocoel (body cavity) and/or gavage (force-feeding). We monitored larval survival and employed a range of cellular and biochemical assays to assess the potential harmful effects of okadaic acid. Okadaic acid at concentrations >75 ng/larva (>242 µg/kg) led to significant reductions in larval survival (>65%) and circulating haemocyte (blood cell) numbers (>50%) within 24 h post-inoculation. In the haemolymph, okadaic acid reduced haemocyte viability and increased phenoloxidase activities. In the midgut, okadaic acid induced oxidative damage as determined by increases in superoxide dismutase activity and levels of malondialdehyde (i.e., lipid peroxidation). Our observations of insect larvae correspond broadly to data published using rodent models of shellfish poisoning toxidrome, including complementary LD50 values; 206–242 μg/kg in mice, ~239 μg/kg in G. mellonella. These data support the use of this insect as a surrogate model for the investigation of marine toxins, which offers distinct ethical and financial incentives

    Low Prevalence of Conjunctival Infection with Chlamydia trachomatis in a Treatment-Naïve Trachoma-Endemic Region of the Solomon Islands

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    Trachoma is endemic in several Pacific Island states. Recent surveys across the Solomon Islands indicated that whilst trachomatous inflammation-follicular (TF) was present at levels warranting intervention, the prevalence of trachomatous trichiasis (TT) was low. We set out to determine the relationship between chlamydial infection and trachoma in this population. We conducted a population-based trachoma prevalence survey of 3674 individuals from two Solomon Islands provinces. Participants were examined for clinical signs of trachoma. Conjunctival swabs were collected from all children aged 1-9 years. We tested swabs for Chlamydia trachomatis (Ct) DNA using droplet digital PCR. Chlamydial DNA from positive swabs was enriched and sequenced for use in phylogenetic analysis. We observed a moderate prevalence of TF in children aged 1-9 years (n = 296/1135, 26.1%) but low prevalence of trachomatous inflammation-intense (TI) (n = 2/1135, 0.2%) and current Ct infection (n = 13/1002, 1.3%) in children aged 1-9 years, and TT in those aged 15+ years (n = 2/2061, 0.1%). Ten of 13 (76.9%) cases of infection were in persons with TF or TI (p = 0.0005). Sequence analysis of the Ct-positive samples yielded 5/13 (38%) complete (>95% coverage of reference) genome sequences, and 8/13 complete plasmid sequences. Complete sequences all aligned most closely to ocular serovar reference strains. The low prevalence of TT, TI and Ct infection that we observed are incongruent with the high proportion of children exhibiting signs of TF. TF is present at levels that apparently warrant intervention, but the scarcity of other signs of trachoma indicates the phenotype is mild and may not pose a significant public health threat. Our data suggest that, whilst conjunctival Ct infection appears to be present in the region, it is present at levels that are unlikely to be the dominant driving force for TF in the population. This could be one reason for the low prevalence of TT observed during the study

    Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass

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    Lucerna, vol. 3, no. 1 (2008) Special Section: Sustainability

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    This section of Lucerna is dedicated to writings by UMKC undergraduate students about the interplay between humans and the environment. Chris Green's historical geography of the Hawaiian Islands provides a four-billion year perspective of environmental change, including the implications of human settlement; Tom Gault offers a review of key philosophical arguments about western society's relationship with nature; and the results of the 2007 Sustain UMKC Competition are presented to our readership. The top ten suggestions for improving the environmental sustainability of development and operations at the University of Missouri - Kansas City are excerpted, including the two ideas voted most practicable, Emily Monroe's description of a campus-based bicycle loan program, and James Ramirez's design concept for landscaped roofing.UMKC Honors College[Sustainability introduction], by Dustin Grey Jenson -- Gardens in the Sky, by James J. Ramirez - La Promesse de Velo'v: Creative Transportation -- by Emily Monroe - E.S.C.R.O.W. (Environmentally Sound Campus Renewing Our World), by Bruce Copeland -- Community-Wide Vinyl Billboard Recycling, by David Scott Goth -- Maximization of the use of Time and Energy: Two Irreplaceable Resources, by Chelsea Nicole Grigery - The Essence of Sustainability is Adaptability, by James E. Galvin -- Office of Sustainability, by Eric Salmon -- A Growing University: UMKC Community Gardens, by Jessica Farmer
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