978 research outputs found
Developing and Applying a User-friendly Web-based GIS for Participative Environmental Assessment
The strong spatial and temporal dimensions of development plans necessitate certain requirements in relation to the analytical tools applied to support Strategic Environmental
Assessment (SEA) processes. The nature of plans and, subsequently, spatial data requires presenting them in graphic format. Similarly, temporal variation can often be represented in visual form by spatially illustrating changes over-time. Furthermore, it is estimated that up to
85% of all data have a spatial component and, therefore, can be mapped using Geographic Information Systems (GIS) (Chan and Easa, 2000). In this context, the graphic display and analytical potential of GIS can significantly contribute to SEA of development plans by facilitating and enhancing the various stages of the process
The costs of accessible quality assured syphilis diagnostics: informing quality systems for rapid syphilis tests in a Tanzanian setting.
OBJECTIVES: To determine the costs of Rapid Syphilis Test (RSTs) as compared with rapid plasma reagin (RPR) when implemented in a Tanzanian setting, and to determine the relative impact of a quality assurance (QA) system on the cost of RST implementation. METHODS: The incremental costs for RPR and RST screening programmes in existing antenatal care settings in Geita District, Tanzania were collected for 9 months in subsequent years from nine health facilities that varied in size, remoteness and scope of antenatal services. The costs per woman tested and treated were estimated for each facility. A sensitivity analysis was constructed to determine the impact of parameter and model uncertainty. FINDINGS: In surveyed facilities, a total of 6362 women were tested with RSTs compared with 224 tested with RPR. The range of unit costs was 3.13 per woman screened and 32.67 per woman treated. Unit costs for the QA system came to $0.51 per woman tested, of which 50% were attributed to salaries and transport for project personnel. CONCLUSIONS: Our results suggest that rapid syphilis diagnostics are very inexpensive in this setting and can overcome some critical barriers to ensuring universal access to syphilis testing and treatment. The additional costs for implementation of a quality system were found to be relatively small, and could be reduced through alterations to the programme design. Given the potential for a quality system to improve quality of diagnosis and care, we recommend that QA activities be incorporated into RST roll-out
Inhibitory Control Processes and the Strategies That Support Them during Hand and Eye Movements
Background and Aims: Adaptive behavior depends on the ability to voluntarily
suppress context-inappropriate behaviors, a process referred to as response inhibition.
Stop Signal tests (SSTs) are the most frequently studied paradigm used to assess
response inhibition. Previous studies of SSTs have indicated that inhibitory control
behavior can be explained using a common model in which GO and STOP processes
are initiated independent from one and another, and the process that is completed first
determines whether the behavior is elicited (GO process) or terminated (STOP process).
Consistent with this model, studies have indicated that individuals strategically delay
their behaviors during SSTs in order to increase their stopping abilities. Despite being
controlled by distinct neural systems, prior studies have largely documented similar
inhibitory control performance across eye and hand movements. Though, no existing
studies have compared the extent to which individuals strategically delay behavior
across different effectors is not yet clear. Here, we compared the extent to which
inhibitory control processes and the cognitive strategies that support them during
oculomotor and manual motor behaviors.
Methods: We examined 29 healthy individuals who performed parallel oculomotor
and manual motor SSTs. Participants also completed a separate block of GO trials
administered prior to the Stop Signal tests to assess baseline reaction times for each
effector and reaction time increases during interleaved GO trials of the SST.
Results: Our results showed that stopping errors increased for both effectors as
the interval between GO and STOP cues was increased (i.e., stop signal delay), but
performance deteriorated more rapidly for eye compared to hand movements with
increases in stop signal delay. During GO trials, participants delayed the initiation
of their responses for each effector, and greater slowing of reaction times on GO
trials was associated with increased accuracy on STOP trials for both effectors.
However, participants delayed their eye movements to a lesser degree than their hand
movements, and strategic reaction time slowing was a stronger determinant of stopping
accuracy for hand compared to eye movements. Overall, stopping accuracies for eye
and hand movements were only modestly correlated, and the time it took individuals to
cancel a response was not related for eye and hand movements.
Discussion and Conclusion: Our findings that GO and STOP processes are
independent and that individuals strategically delay their behavioral responses to
increase stopping accuracy regardless of effector indicate that inhibitory control of
Frontiers in Psychology | www.frontiersin.org 1 December 2016 | Volume 7 | Article 1927
Schmitt et al. Inhibitory Control of Hand and Eye Movements
oculomotor and manual motor behaviors both follow common guiding principles.
Yet, our findings document that eye movements are more difficult to inhibit than
hand movements, and the timing, magnitude, and impact of cognitive control
strategies used to support voluntary response inhibition are less robust for eye
compared to hand movements. This suggests that inhibitory control systems also
show unique characteristics that are behavior-dependent. This conclusion is consistent
with neurophysiological evidence showing important differences in the architecture and
functional properties of the neural systems involved in inhibitory control of eye and hand
movements. It also suggests that characterizing inhibitory control processes in health
and disease requires effector-specific analysis.NIH Autism Center of Excellence P50HD055751; MH092696, and the Kansas Center for Autism Research and Training Research Investment Council Strategic Initiative Gran
Top-down control of visual sensory processing during an ocular motor response inhibition task
The study addressed whether top-down control of visual cortex supports volitional behavioral control in a novel antisaccade task. The hypothesis was that anticipatory modulations of visual cortex activity would differentiate trials on which subjects knew an anti- versus a pro-saccade response was required. Trials consisted of flickering checkerboards in both peripheral visual fields, followed by brightening of one checkerboard (target) while both kept flickering. Neural activation related to checkerboards before target onset (bias signal) was assessed using electroencephalography. Pretarget visual cortex responses to checkerboards were strongly modulated by task demands (significantly lower on antisaccade trials), an effect that may reduce the predisposition to saccade generation instigated by visual capture. The results illustrate how top-down sensory regulation can complement motor preparation to facilitate adaptive voluntary behavioral control
Resting-State Brain Network Dysfunctions Associated With Visuomotor Impairments in Autism Spectrum Disorder
This work is licensed under a Creative Commons Attribution 4.0 International License.Background: Individuals with autism spectrum disorder (ASD) show elevated levels of motor variability that are associated with clinical outcomes. Cortical–cerebellar networks involved in visuomotor control have been implicated in postmortem and anatomical imaging studies of ASD. However, the extent to which these networks show intrinsic functional alterations in patients, and the relationship between intrinsic functional properties of cortical–cerebellar networks and visuomotor impairments in ASD have not yet been clarified.
Methods: We examined the amplitude of low-frequency fluctuation (ALFF) of cortical and cerebellar brain regions during resting-state functional MRI (rs-fMRI) in 23 individuals with ASD and 16 typically developing (TD) controls. Regions of interest (ROIs) with ALFF values significantly associated with motor variability were identified for for patients and controls respectively, and their functional connectivity (FC) to each other and to the rest of the brain was examined.
Results: For TD controls, greater ALFF in bilateral cerebellar crus I, left superior temporal gyrus, left inferior frontal gyrus, right supramarginal gyrus, and left angular gyrus each were associated with greater visuomotor variability. Greater ALFF in cerebellar lobule VIII was associated with less visuomotor variability. For individuals with ASD, greater ALFF in right calcarine cortex, right middle temporal gyrus (including MT/V5), left Heschl's gyrus, left post-central gyrus, right pre-central gyrus, and left precuneus was related to greater visuomotor variability. Greater ALFF in cerebellar vermis VI was associated with less visuomotor variability. Individuals with ASD and TD controls did not show differences in ALFF for any of these ROIs. Individuals with ASD showed greater posterior cerebellar connectivity with occipital and parietal cortices relative to TD controls, and reduced FC within cerebellum and between lateral cerebellum and pre-frontal and other regions of association cortex.
Conclusion: Together, these findings suggest that increased resting oscillations within visuomotor networks in ASD are associated with more severe deficits in controlling variability during precision visuomotor behavior. Differences between individuals with ASD and TD controls in the topography of networks showing relationships to visuomotor behavior suggest atypical patterns of cerebellar–cortical specialization and connectivity in ASD that underlies previously documented visuomotor deficits.NIMH K23 (MH092696)NIMH R01 (MH112734)Kansas Center for Autism Research and Training (K-CART) Research Investment Council Strategic Initiative GrantNICHD U54 Kansas Intellectual and Developmental Disabilities Research Center Award (U54HD090216)National Natural Science Foundation of China Award (grant no. 81371527
Alterations in the functional neural circuitry supporting flexible choice behavior in autism spectrum disorders
Restricted and repetitive behaviors, and a pronounced preference for behavioral and environmental consistency, are distinctive characteristics of autism spectrum disorder (ASD). Alterations in frontostriatal circuitry that supports flexible behavior might underlie this behavioral impairment. In an functional magnetic resonance imaging study of 17 individuals with ASD, and 23 age-, gender- and IQ-matched typically developing control participants, reversal learning tasks were used to assess behavioral flexibility as participants switched from one learned response choice to a different response choice when task contingencies changed. When choice outcome after reversal was uncertain, the ASD group demonstrated reduced activation in both frontal cortex and ventral striatum, in the absence of task performance differences. When the outcomes of novel responses were certain, there was no difference in brain activation between groups. Reduced activation in frontal cortex and ventral striatum suggest problems in decision-making and response planning, and in processing reinforcement cues, respectively. These processes, and their integration, are essential for flexible behavior. Alterations in these systems may therefore contribute to a rigid adherence to preferred behavioral patterns in individuals with an ASD. These findings provide an additional impetus for the use of reversal learning paradigms as a translational model for treatment development targeting the domain of restricted and repetitive behaviors in ASD
Differentiation of 3-O-Sulfated Heparin Disaccharide Isomers: Identification of Structural Aspects of the Heparin CCL2 Binding Motif
The presence of 3-O-sulfated glucosamine residues in heparin or heparan sulfate plays a role in binding to antithrombin III and HSV infection. In this study, tandem mass spectrometry was used to differentiate between two heparin disaccharide isomers containing variable sulfate at C6 in a common disaccharide and C3 in a more rare one. The dissociation patterns shown by MS2 and MS3 were clearly distinguishable between the isomers, allowing their differentiation and quantitation. Using this technique, we show that an octasaccharide with 11 sulfate groups with high affinity for inflammatory chemokine CCL2 does not contain 3-O-sulfated disaccharides
The role of cerebellar circuitry alterations in the pathophysiology of autism spectrum disorders
The cerebellum has been repeatedly implicated in gene expression, rodent model and post-mortem studies of autism spectrum disorder (ASD). How cellular and molecular anomalies of the cerebellum relate to clinical manifestations of ASD remains unclear. Separate circuits of the cerebellum control different sensorimotor behaviors, such as maintaining balance, walking, making eye movements, reaching, and grasping. Each of these behaviors has been found to be impaired in ASD, suggesting that multiple distinct circuits of the cerebellum may be involved in the pathogenesis of patients' sensorimotor impairments. We will review evidence that the development of these circuits is disrupted in individuals with ASD and that their study may help elucidate the pathophysiology of sensorimotor deficits and core symptoms of the disorder. Preclinical studies of monogenetic conditions associated with ASD also have identified selective defects of the cerebellum and documented behavioral rescues when the cerebellum is targeted. Based on these findings, we propose that cerebellar circuits may prove to be promising targets for therapeutic development aimed at rescuing sensorimotor and other clinical symptoms of different forms of ASD
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