BlindBuilder : a new encoding to evolve Lego-like structures

This paper introduces a new representation for assemblies of small Lego-like elements: structures are indirectly encoded as construction plans. This representation shows some interesting properties such as hierarchy, modularity and easy constructibility checking by definition. Together with this representation, efficient GP operators are introduced that allow efficient and fast evolution, as witnessed by the results on two construction problems that demonstrate that the proposed approach is able to achieve both compactness and reusability of evolved components

Central excitability contributes to supramaximal volitional contractions in human incomplete spinal cord injury

Individuals with a motor incomplete spinal cord injury (SCI) present clinically with partial control of muscles below the site of the injury, but experience profound weakness which can limit the ability to perform functional tasks such as walking. Interestingly, when individuals with an incomplete SCI are asked to maximally and repeatedly contract their quadriceps muscles, they demonstrate an increase in the peak force generated; individuals without SCI experience a decline in force, or ‘fatigue’. Following these repeated maximal efforts, reflex responses to electrical stimulation over the quadriceps muscle elicited amplified and prolonged, involuntary motor activity. Such responses were not observed prior to the maximal contractions, and were not observed in neurologically intact subjects. This finding suggests that increases in spinal excitability following these maximal efforts may enhance force generating capacity, and provides insight into possible novel therapeutic interventions to restore function following SCI

Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI

Spinal cord injury (SCI) is a debilitating disorder, which produces profound deficits in volitional motor control. Following medical stabilization, recovery from SCI typically involves long term rehabilitation. While recovery of walking ability is a primary goal in many patients early after injury, those with a motor incomplete SCI, indicating partial preservation of volitional control, may have the sufficient residual descending pathways necessary to attain this goal. However, despite physical interventions, motor impairments including weakness, and the manifestation of abnormal involuntary reflex activity, called spasticity or spasms, are thought to contribute to reduced walking recovery. Doctrinaire thought suggests that remediation of this abnormal motor reflexes associated with SCI will produce functional benefits to the patient. For example, physicians and therapists will provide specific pharmacological or physical interventions directed towards reducing spasticity or spasms, although there continues to be little empirical data suggesting that these strategies improve walking ability

Substance P in the Dorsal Motor Nucleus of the Vagus Evokes Gastric Motor Inhibition via Neurokinin 1 Receptor in Rat 1

ABSTRACT Many gastrointestinal stimuli result in gastric fundic relaxation. This information is integrated at the interface of vagal afferents and efferents in the dorsal vagal complex. Substance P (SP) is present in this region, and the neurokinin 1 receptor (NK 1 R) is highly expressed in preganglionic neurons of the dorsal motor nucleus of the vagus (DMN). However, its functional effects on vagal motor output to the stomach have not been investigated. Therefore, we determined the gastric motor effects of stereotaxic microinjection of SP and selective tachykinin receptor agents into the DMN of anesthetized rats. Dose-related decreases in intragastric pressure and antral motility were obtained on the microinjection of SP (135 and 405 pmol) into the DMN, without cardiovascular changes. Similar decreases in intragastric pressure were noted after the microinjection of [Sar 9 ,Met(O 2 ) 11 ]SP (NK 1 R agonist; 135 pmol) but not senktide (NK 3 R agonist; 135 pmol) or vehicle. The gastric motor inhibition evoked by SP (135 pmol) was attenuated by prior microinjection of 2-methoxy-5-tetrazol-1-yl-benzyl-(2-phenyl-piperidin-3-yl)-amine (GR203040; 1 nmol; NK 1 R antagonist). Vagotomy or hexamethonium (15 mg/kg i.v.) completely abolished the gastric relaxation evoked by SP (135 pmol) microinjected into the DMN. We conclude that SP acts on NK 1 R preganglionic cholinergic vagal neurons in the DMN, which control enteric nonadrenergic noncholinergic motor inhibition of the fundus. The potential relevance is that an antiemetic site of action of NK 1 R antagonists may be in the DMN to prevent excitation of neurons controlling fundic relaxation, which is an essential prodromal component of emesis. Many stimuli to the gastrointestinal tract result in hormonal ("endoneurocrine") or neuronal feedback to other regions of the gut, and the vagus nerve is intimately involved in conveying this information to the upper gastrointestinal tract. Integration of "long-loop" vagal afferent-efferent pathways from the gut occurs in the dorsal vagal complex of the hindbrain medulla. This complex comprises the dorsal motor nucleus of the vagus (DMN), where preganglionic motor neurons innervating the gastrointestinal tract are located, and the nucleus tractus solitarius, where primary visceral afferents terminate. Preganglionic neurons in the DMN target the stomach One candidate neurotransmitter in the dorsal vagal complex that could mediate fundic relaxation is substance P (SP). The microinjection of SP into the nucleus tractus solitarius evokes gastric relaxatio

Celebrating is remembering: OUTing the Past as a study in the reflective and transformative potential of small events

Since its emergence in the latter half of the twentieth century, public history has engendered ongoing transformations in the creation and dissemination of knowledge. Its aims, as well as efforts undertaken as part of its praxis, are reminders that collaborative engagements with individuals and communities can simultaneously serve to commemorate, educate and empower. Recent scholarship that examines pop-up events underscores both their significance to public history and the innovative potential they represent in celebrating LGBT+ lives and experiences. In particular, the extent to which they encourage considerations of space that are more attentive to localities and pluralities is indicative of the disruptive significance of small-scale events. Among other possibilities that lend themselves to expanding the reach of public history, particularly by adopting new modes of interpretation that place a premium on active engagement, creative arts programming provides a pathway to stimulating interest in exploring and understanding the past. The work of OUTing the Past, a UK-based organisation, effectively reflects aspirations associated with public history, with the logistical benefits of pop-up events and the contributions of creative productions finding purchase in its programming. Documenting the commitments it makes to re/centring history and the frameworks it has strategically developed in realising these provides the impetus for this critical study of a multifaceted approach to promoting small-scale LGBT+ celebrations

A Physiologically Based Clinical Measure for Spastic Reflexes in Spinal Cord Injury

Objective: To test the validity of the Spinal Cord Assessment Tool for Spastic reflexes (SCATS), a clinical tool intended to rate spastic motor behavior after spinal cord injury (SCI). Design: By using correlational analyses, the SCATS was validated using concurrent measurements of kinematics and electromyograms and traditional assessments of spasms and spastic hypertonia. Setting: Research laboratory (kinematics and electromyography) and outpatient medical clinic (traditional measures of spastic hypertonia). Participants: Eleven people with SCI were used for kinematic and electromyographic measurements. Seventeen people with SCI were used for comparison with other clinical scales. Interventions: Not applicable. Main outcome measures: Kinematic and surface electromyographic measurements of the tested lower extremity were used to quantify magnitude and/or duration of motor behaviors, and the Penn Spasm Frequency Scale (PSFS) and the Ashworth Scale were used to measure spasm frequency and resistance to joint movement for the hip flexors, knee flexors, and ankle plantarflexors, respectively. Concurrently, the SCATS was used to assess the clonus response to an imposed ankle dorsiflexion, the flexion response to a stimulus to the foot, and the knee extensor activity in response to an imposed leg extension. Each component of the SCATS was compared with the Ashworth Scale, the PSFS, and kinematic and electromyographic measurements by using the Spearman rank correlation test. Results:Clonus, flexor spasm, and extensor spasm responses measured by using the SCATS correlated significantly with kinematic and electromyographic recordings (PP\u3c.05). Conclusions: The SCATS produced a valid measure of 3 distinct types of spastic motor behaviors in SCI and may provide a complementary tool for measuring spastic hypertonia. Such a measure is valuable because current assessment tools do not differentiate between the different types of spastic motor behaviors that manifest after SCI. Distinguishing the 3 spastic reactions using an efficient and valid clinical tool may help guide management of spastic hypertonia in SCI

Repetitive fracturing during spine extrusion at Unzen volcano, Japan

Rhythmic seismicity associated with spine extrusion is a well-documented phenomenon at a number of dome-forming volcanic systems. At Unzen volcano, Japan, a 4-year dome-forming eruption concluded with the emplacement of a spine from October 1994 to February 1995, offering a valuable opportunity to further investigate seismogenic processes at dome-forming volcanoes. Using continuous data recorded at a seismic station located close to the dome, this study explores trends in the seismic activity during the extrusion of the spine. We identify a total of 12 208 volcano-seismic events in the period between October 1994 and February 1995. Hourly event counts indicate cyclic activity with periods of ∼ 40 to ∼ 100 h, attributed to pulsatory ascent defined by strain localisation and faulting at the conduit margins. Waveform correlation revealed two strong clusters (a.k.a. multiplets, families) which are attributed to fracturing along the margins of the shallow, ascending spine. Further analysis indicates variable seismic velocities during the spine extrusion as well as migration of the cluster sources along the spine margins. Our interpretation of the results from seismic data analyses is supported by previously published field and experimental observations, suggesting that the spine was extruded along an inclined conduit with brittle and ductile deformation occurring along the margins. We infer that changes in stress conditions acting on the upper and lower spine margins led to deepening and shallowing of the faulting sources, respectively. We demonstrate that the combination of geophysical, field and experimental evidence can help improve physical models of shallow conduit processes

Global distributed evolution of L-systems fractals

Internet based parallel genetic programming (GP) creates fractal patterns like Koch’s snow flake. Pfeiffer, http://www.cs.ucl.ac.uk/staff/W.Langdon/pfeiffer.html, by analogy with seed/embryo development, uses Lindenmayer grammars and LOGO style turtle graphics written in Javascript and Perl. 298 novel pictures were produced. Images are placed in animated snow globes (computerised snowstorms) by www web browsers anywhere on the planet. We discuss artificial life (Alife) evolving autonomous agents and virtual creatures in higher dimensions from a free format representation in the context of neutral networks, gene duplication and the evolution of higher order genetic operators