Experimental muscle hyperalgesia modulates sensorimotor cortical excitability, which is partially altered by unaccustomed exercise

Impaired corticomotor function is reported in patients with lateral epicondylalgia, but the causal link to pain or musculotendinous overloading is unclear. In this study, sensorimotor cortical changes were investigated using a model of persistent pain combined with an overloading condition. In 24 healthy subjects, the effect of nerve growth factor (NGF)-induced pain, combined with delayed-onset muscle soreness (DOMS), was examined on pain perception, pressure pain sensitivity, maximal force, and sensorimotor cortical excitability. Two groups (NGF alone and NGF + DOMS) received injections of NGF into the extensor carpi radialis brevis (ECRB) muscle at day 0, day 2, and day 4. At day 4, the NGF + DOMS group undertook wrist eccentric exercise to induce DOMS in the ECRB muscle. Muscle soreness scores, pressure pain thresholds over the ECRB muscle, maximal grip force, transcranial magnetic stimulation mapping of the cortical ECRB muscle representation, and somatosensory-evoked potentials from radial nerve stimulation were recorded at day 0, day 4, and day 6. Compared with day 0, day 4 showed in both groups: (1) increased muscle soreness (P < 0.01); (2) reduced pressure pain thresholds (P < 0.01); (3) increased motor map volume (P < 0.01); and (4) decreased frontal N30 somatosensory-evoked potential. At day 6, compared with day 4, only the DOMS + NGF group showed: (1) increased muscle soreness score (P < 0.01); (2) decreased grip force (P < 0.01); and (3) decreased motor map volume (P < 0.05). The NGF group did not show any difference on the remaining outcomes from day 4 to day 6. These data suggest that sustained muscle pain modulates sensorimotor cortical excitability and that exercise-induced DOMS alters pain-related corticomotor adaptation

High frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex modulates sensorimotor cortex function in the transition to sustained muscle pain

Based on reciprocal connections between the dorsolateral prefrontal cortex (DLPFC) and basal-ganglia regions associated with sensorimotor cortical excitability, it was hypothesized that repetitive transcranial magnetic stimulation (rTMS) of the left DLPFC would modulate sensorimotor cortical excitability induced by muscle pain. Muscle pain was provoked by injections of nerve growth factor (end of Day-0 and Day-2) into the right extensor carpi radialis brevis (ECRB) muscle in two groups of 15 healthy participants receiving 5 daily sessions (Day-0 to Day-4) of active or sham rTMS. Muscle pain scores and pressure pain thresholds (PPTs) were collected (Day-0, Day-3, Day-5). Assessment of motor cortical excitability using TMS (mapping cortical ECRB muscle representation) and somatosensory evoked potentials (SEPs) from electrical stimulation of the right radial nerve were recorded at Day-0 and Day-5. At Day-0 versus Day-5, the sham compared to active group showed: Higher muscle pain scores and reduced PPTs (P < 0.04); decreased frontal N30 SEP (P < 0.01); increased TMS map volume (P < 0.03). These results indicate that muscle pain exerts modulatory effects on the sensorimotor cortical excitability and left DLPFC rTMS has analgesic effects and modulates pain-induced sensorimotor cortical adaptations. These findings suggest an important role of prefrontal to basal-ganglia function in sensorimotor cortical excitability and pain processing

Behavioral abnormalities in wild birds and reptiles and use of enrichment proposal

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Chemistry, antioxidant, antibacterial and antifungal activities of volatile oils and their components.

The present paper reports the chemical composition, antioxidant and antibacterial activities of several essential oils and their components. Analysis showed that three oils (Carum carvi L., Verbena officinalis L. and Majorana hortensis L.) contained predominantly oxygenated monoterpenes, while others studied (Pimpinella anisum L., Foeniculum vulgare Mill.) mainly contained anethole. C. carvi, V. officinalis and M. hortensis oils exhibited the most potent antioxidant activity, due their contents of carvacrol, anethole and estragol. Antibacterial action was assessed against a range of pathogenic and useful bacteria and fungi of agro-food interest. V. officinalis and C. carvi oils proved the most effective, in particular against Bacillus cereus and Pseudomonas aeruginosa. Carvacrol proved most active against Escherichia coli, and completely inhibited the growth of Penicillium citrinum. The oils proved inactive towards some Lactobacilli strains, whereas single components showed an appreciable activity. These results may be important for use of the essential oils as natural preservatives for food products

Nondimensional Shape Optimization of Nonprismatic Beams with Sinusoidal Lateral Profile

The present paper deals with the optimal design of nonprismatic beams, i.e., beams with variable cross section. To set the optimization problem, Euler-Bernoulli unshearable beam theory is considered and the elastica equation expressing the transverse displacement as a function of the applied loads is reformulated into a system of four differential equations involving kinematic components and internal forces. The optimal solution (in terms of volume) must satisfy two constraints: the maximum Von Mises equivalent stress must not exceed an (ideal) strength, and the maximum vertical displacement is limited to a fraction of beam length. To evaluate the maximum equivalent stress in the beam, normal and shear stresses have been considered. The former was evaluated through the Navier formula, and the latter through a formula derived from Jourawsky and holding for straight and untwisted beams with bisymmetric variable cross sections. The optimal solutions as function of material unit weight, maximum strength, and applied load are presented and discussed. It is shown that the binding constraint is usually represented by the maximum stress in the beam, and that applied load and strength affect the solution more than material unit weight. To maintain the generality of the solution, the nondimensionalization according to Buckingham pi-theorem is implemented and a design abacus is proposed

Chiral interface states in p-n graphene junctions

We present a theoretical analysis of unidirectional interface states which form near p−n junctions in a graphene monolayer subject to a homogeneous magnetic field. The semiclassical limit of these states corresponds to trajectories propagating along the p−n interface by a combined skipping-snaking motion. Studying the two-dimensional Dirac equation with a magnetic field and an electrostatic potential step, we provide and discuss the exact and essentially analytical solution of the quantum-mechanical eigenproblem for both a straight and a circularly shaped junction. The spectrum consists of localized Landau-like and unidirectional snaking-skipping interface states, where we always find at least one chiral interface state. For a straight junction and at energies near the Dirac point, when increasing the potential step height, the group velocity of this state interpolates in an oscillatory manner between the classical drift velocity in a crossed electromagnetic field and the semiclassical value expected for a purely snaking motion. Away from the Dirac point, chiral interface states instead resemble the conventional skipping (edge-type) motion found also in the corresponding Schrödinger case. We also investigate the circular geometry, where chiral interface states are predicted to induce sizable equilibrium ring currents

Las nuevas formas de gobierno poblacional: sobre individualización e ingeniería social

Los años 90 han sido consignados como un período de grandes transformaciones en la matriz de protección social y los dispositivos de intervención sociopolítica. Estos años se caracterizan por su fertilidad con relación a la implementación de nuevas políticas sociales y a la legislación relativa a temáticas vinculadas a la infancia, la familia y a la condición de la mujer. Son sumamente significativos si tenemos en cuenta la incidencia de los organismos internacionales en lo que respecta a las politicas sociales en general y a la Reforma del Estado en particular. Las décadas analizadas conforman un período altamente productivo desde el punto de vista de la elaboración de diagnóstico y recomendaciones que como señala Midaglia fueron fundamentales a la hora de redefinir las formas de gestión de la pobreza y los agentes públicos y privados participantes en ella. A la hora de colectivizar hallazgos se hace necesario encontrar el equilibrio entre capacidad de síntesis y claridad conceptual y, además, seleccionar aquellos que consideramos más pertinentes para expresar el espíritu de una época. Dados los límites del trabajo se presenta una selección de los resultados producto de las investigaciones recientemente desarrolladas por sus autoras, que contribuyen al análisis de la emergencia y consolidación de nuevas formas de gobierno poblacional materializadas en propuestas de protección social dirigidas a la infancia y la familia, así como su fuerte relación con los procesos de individualización social característicos de la modernidad tardía

User Value in Modern Payment Platforms: A Graph Approach

Payment platforms have significantly evolved in recent years to keep pace with the proliferation of online and cashless payments. These platforms are increasingly aligned with online social networks, allowing users to interact with each other and transfer small amounts of money in a Peer-to-Peer fashion. This poses new challenges for analysing payment data, as traditional methods are only user-centric or business-centric and neglect the network users build during the interaction. This paper proposes a first methodology for measuring user value in modern payment platforms. We combine quantitative user-centric metrics with an analysis of the graph created by users’ activities and its topological features inspired by the evolution of opinions in social networks. We showcase our approach using a dataset from a large operational payment platform and show how it can support business decisions and marketing campaign design, e.g., by targeting specific users

The generic Hanna Neumann conjecture and post correspondence problem

"Vegeu el resum a l'inici del document del fitxer adjunt"