Effect of types and anatomic arrangement of painful stimuli on conditioned pain modulation

Reduced pain perception during painful stimulation to another body region (ie, conditioned pain modulation [CPM]) is considered important for pain modulation and development of pain disorders. The various methods used to study CPM limit comparison of findings. We investigated the influence of key methodologic variations on CPM and the properties of CPM when the back is used for the test stimulus or the conditioning stimulus (CS). Two different test stimuli (pressure pain threshold and pain response to suprathreshold heat [Pain-45, ie, pain rated at 45 on a 0–100 numeric rating scale]) were assessed before and during application of a noxious or non-noxious (sham) CS. Eight blocks of trials varied the anatomic location (back and forearms) and arrangement (body side) of the stimuli. Pressure pain threshold (as the test stimulus) increased during application of noxious, but not non-noxious, CS when stimuli were applied to opposite body sides or heterotopic sites on one body side. Inconsistent with pain-induced CPM, Pain-45 decreased during both noxious and non-noxious CS. These findings indicate that 1) pressure pain threshold can be more confidently interpreted with respect to CPM evoked by a painful stimulus than Pain-45, 2) the back and forearm are equally effective as sites for stimuli, and 3) stimuli arrangement does not influence CPM, except for identical anatomic regions on the same body side. Perspective: This study indicates that pressure pain threshold as the test stimulus provides a more valid measure of pain-induced CPM than pain response to a suprathreshold heat stimulus. Induction and magnitude of CPM is independent of stimuli arrangement, as long as ipsilateral homotopic sites are avoided. These findings clarify methods to study CPM

Effect of types and anatomic arrangement of painful stimuli on conditioned pain modulation

Reduced pain perception during painful stimulation to another body region (ie, conditioned pain modulation [CPM]) is considered important for pain modulation and development of pain disorders. The various methods used to study CPM limit comparison of findings. We investigated the influence of key methodologic variations on CPM and the properties of CPM when the back is used for the test stimulus or the conditioning stimulus (CS). Two different test stimuli (pressure pain threshold and pain response to suprathreshold heat [Pain-45, ie, pain rated at 45 on a 0–100 numeric rating scale]) were assessed before and during application of a noxious or non-noxious (sham) CS. Eight blocks of trials varied the anatomic location (back and forearms) and arrangement (body side) of the stimuli. Pressure pain threshold (as the test stimulus) increased during application of noxious, but not non-noxious, CS when stimuli were applied to opposite body sides or heterotopic sites on one body side. Inconsistent with pain-induced CPM, Pain-45 decreased during both noxious and non-noxious CS. These findings indicate that 1) pressure pain threshold can be more confidently interpreted with respect to CPM evoked by a painful stimulus than Pain-45, 2) the back and forearm are equally effective as sites for stimuli, and 3) stimuli arrangement does not influence CPM, except for identical anatomic regions on the same body side. Perspective: This study indicates that pressure pain threshold as the test stimulus provides a more valid measure of pain-induced CPM than pain response to a suprathreshold heat stimulus. Induction and magnitude of CPM is independent of stimuli arrangement, as long as ipsilateral homotopic sites are avoided. These findings clarify methods to study CPM

Music SOFA: An architecture for semantically informed recomposition of Digital Music Objects

We describe the design and implementation of a semantic music system which illustrates the assembly of a music composition using semantically annotated music fragments. The system, which we call SOFA (SOFA Ontological Fragment Assembler), demonstrates architectural design principles which may have more general applicability in the semantic music domain, notably the adoption of the Linked Data Platform to realise service components of the end-to-end pipeline so that data specialisation takes the place of service specialisation. The prototype builds upon two existing tools developed by the authors: Music Encoding and Linked Data (MELD), which augments and extends MEI structures with semantic Web Annotations capable of addressing musically meaningful score sections, and Numbers Into Notes, an algorithmic composition tool that acts as a 'semantic signal generator' to drive the tool chain. The system demonstrates the concept of Digital Musical Objects (DMOs), and in particular DMO processing and recomposition

Music SOFA: An architecture for semantically informed recomposition of Digital Music Objects

We describe the design and implementation of a semantic music system which illustrates the assembly of a music composition using semantically annotated music fragments. The system, which we call SOFA (SOFA Ontological Fragment Assembler), demonstrates architectural design principles which may have more general applicability in the semantic music domain, notably the adoption of the Linked Data Platform to realise service components of the end-to-end pipeline so that data specialisation takes the place of service specialisation. The prototype builds upon two existing tools developed by the authors: Music Encoding and Linked Data (MELD), which augments and extends MEI structures with semantic Web Annotations capable of addressing musically meaningful score sections, and Numbers Into Notes, an algorithmic composition tool that acts as a 'semantic signal generator' to drive the tool chain. The system demonstrates the concept of Digital Musical Objects (DMOs), and in particular DMO processing and recomposition

Plans and performances: Parallels in the production of science and music

Whether in the science lab or the music studio, we go in with a plan, we perform, and we make a record of that performance for distribution, consumption, and reuse. Both domains are increasingly data-intensive, with the adoption of new technology, and also socially intensive with democratised and growing citizen engagement. The music industry has embraced digital technology throughout the lifecycle from composition to consumption; scientific practice, and scholarly communication, are also undergoing transformation. Is the music industry more digital than science? We suggest that comparing and contrasting these two systems will provide insights of mutual benefit. Our investigation explores the notion of the Digital Music Object, analogous to the Research Object, for rich capture, sharing and reuse of both process and content

Poor sleep versus exercise: A duel to decide whether pain resolves or persists after injury.

Poor sleep is thought to enhance pain via increasing peripheral and/or central sensitization. Aerobic exercise, conversely, relives pain via reducing sensitization, among other mechanisms. This raises two clinical questions: (1) does poor sleep contribute to the transition from acute-to-persistent pain, and (2) can exercise protect against this transition? This study tested these questions and explored underlying mechanisms in a controlled injury model. Twenty-nine adult female Sprague-Dawley rats performed an intensive lever-pulling task for 4 weeks to induce symptoms consistent with clinical acute-onset overuse injury. Rats were then divided into three groups and exposed for 4 weeks to either: voluntary exercise via access to a running wheel, sleep disturbance, or both. Pain-related behaviours (forepaw mechanical sensitivity, reflexive grip strength), systemic levels of brain derived neurotrophic factor (BDNF), estradiol and corticosterone, and white blood cells (WBC) were assessed pre-injury, post-injury and post-intervention. Mechanical sensitivity increased post-injury and remained elevated with sleep disturbance alone, but decreased to pre-injury levels with exercise both with and without sleep disturbance. Reflexive grip strength decreased post-injury but recovered post-intervention-more with exercise than sleep disturbance. BDNF increased with sleep disturbance alone, remained at pre-injury levels with exercise regardless of sleep, and correlated with mechanical sensitivity. WBCs and estradiol increased with exercise alone and together with sleep disturbance, respectively. Corticosterone was not impacted by injury/intervention. Findings provide preliminary evidence for a role of poor sleep in the transition from acute-to-persistent pain, and the potential for aerobic exercise to counter these effects. BDNF might have a role in these relationships