Astronomical Handbooks and Tables from the Islamic World (750-1900): an Interim Report

The purpose of this paper is to present an overview of the current state of research on the medieval Islamic astronomical handbook known as zijes in particular, and astronomical tables in general

Transcutaneous Electrical Neuromodulation of the Cervical Spinal Cord Depends Both on the Stimulation Intensity and the Degree of Voluntary Activity for Training. A Pilot Study

Electrical enabling motor control (eEmc) through transcutaneous spinal cord stimulation offers promise in improving hand function. However, it is still unknown which stimulus intensity or which muscle force level could be better for this improvement. Nine healthy individuals received the following interventions: (i) eEmc intensities at 80%, 90% and 110% of abductor pollicis brevis motor threshold combined with hand training consisting in 100% handgrip strength; (ii) hand training consisting in 100% and 50% of maximal handgrip strength combined with 90% eEmc intensity. The evaluations included box and blocks test (BBT), maximal voluntary contraction (MVC), F wave persistency, F/M ratio, spinal and cortical motor evoked potentials (MEP), recruitment curves of spinal MEP and cortical MEP and short-interval intracortical inhibition. The results showed that: (i) 90% eEmc intensity increased BBT, MVC, F wave persistency, F/M ratio and cortical MEP recruitment curve; 110% eEmc intensity increased BBT, F wave persistency and cortical MEP and recruitment curve of cortical MEP; (ii) 100% handgrip strength training significantly modulated MVC, F wave persistency, F/M wave and cortical MEP recruitment curve in comparison to 50% handgrip strength. In conclusion, eEmc intensity and muscle strength during training both influence the results for neuromodulation at the cervical level

Cervical electrical neuromodulation effectively enhances hand motor output in healthy subjects by engaging a use-dependent intervention

Electrical enabling motor control (eEmc) through transcutaneous spinal cord stimulation is a non-invasive method that can modify the functional state of the sensory-motor system. We hypothesize that eEmc delivery, together with hand training, improves hand function in healthy subjects more than either intervention alone by inducing plastic changes at spinal and cortical levels. Ten voluntary participants were included in the following three interventions: (i) hand grip training, (ii) eEmc, and (iii) eEmc with hand training. Functional evaluation included the box and blocks test (BBT) and hand grip maximum voluntary contraction (MVC), spinal and cortical motor evoked potential (sMEP and cMEP), and resting motor thresholds (RMT), short interval intracortical inhibition (SICI), and F wave in the abductor pollicis brevis muscle. eEmc combined with hand training retained MVC and increased F wave amplitude and persistency, reduced cortical RMT and facilitated cMEP amplitude. In contrast, eEmc alone only increased F wave amplitude, whereas hand training alone reduced MVC and increased cortical RMT and SICI. In conclusion, eEmc combined with hand grip training enhanced hand motor output and induced plastic changes at spinal and cortical level in healthy subjects when compared to either intervention alone. These data suggest that electrical neuromodulation changes spinal and, perhaps, supraspinal networks to a more malleable state, while a concomitant use-dependent mechanism drives these networks to a higher functional state

Buscando a C19n: el potencial de la Formación Mendiorotz (cuenca de Jaca-Pamplona, Pirineos occidentales) para el GSSP del Bartoniense

El cron C19n es el principal marcador del límite Luteciense/Bartoniense, cuyo GSSP está todavía pendiente de ser determi- nado debido a la ausencia de secciones idóneas a nivel mundial. Aunque el Pirineo occidental alberga numerosas cuencas sedimentarias con formaciones marinas de edad Luteciense y Bartoniense, intentos anteriores de encontrar secciones poten- cialmente interesantes en dicha zona no han dado resultados satisfactorios (Payros et al., 2014). En este resumen se presenta el trabajo de campo que se ha realizado en la parte occidental de la cuenca de Jaca-Pamplona con el objetivo de identificar series estratigráficas susceptibles de ser datadas mediante magnetobioestratigráfía y posicionar el límite Luteciense/Bar- toniense. Fruto de este trabajo se ha explorado el sinclinal de Izaga, en cuya parte oriental afloran series de la Formación Mendiorotz, de edad Luteciense superior/Bartoniense inferior (Payros et al., 1999), caracterizadas por una sedimentación pelágica dominante y una exposición y continuidad estratigráfica idóneas para encontrar el marcador del límite, el cron C19n. Chron C19n is the main marker of the Lutetian/Bartonian boundary, whose GSSP is still to be defined due to the lack of suitable sections worldwide. Although the Western Pyrenees host a number of sedimentary basins with marine formations of Lutetian and Bartonian age, previous attempts of finding prospective sections in the area have resulted in an unsuccess- ful outcome (Payros et al., 2014). Here we present the results of a fieldwork study conducted in the western sector of the Jaca-Pamplona basin with the aim of identifying sedimentary successions where the Lutetian/Bartonian boundary can be found through magnetobiostratigraphic dating. As a result of this search, we have focused our attention on the eastern sector of the Izaga syncline, where dominantly pelagic sediments of the Mendiorotz Formation, upper Lutetian/lower Bartonian in age (Payros et al., 1999), crop out with enough exposure and stratigraphic continuity to allow identification of Chron C19n

Flux regulation of cardiac ryanodine receptor channels

The cardiac type 2 ryanodine receptor (RYR2) is activated by Ca2+-induced Ca2+ release (CICR). The inherent positive feedback of CICR is well controlled in cells, but the nature of this control is debated. Here, we explore how the Ca2+ flux (lumen-to-cytosol) carried by an open RYR2 channel influences its own cytosolic Ca2+ regulatory sites as well as those on a neighboring channel. Both flux-dependent activation and inhibition of single channels were detected when there were super-physiological Ca2+ fluxes (>3 pA). Single-channel results indicate a pore inhibition site distance of 1.2 ± 0.16 nm and that the activation site on an open channel is shielded/protected from its own flux. Our results indicate that the Ca2+ flux mediated by an open RYR2 channel in cells (∼0.5 pA) is too small to substantially regulate (activate or inhibit) the channel carrying it, even though it is sufficient to activate a neighboring RYR2 channel

Analizando la cinética de las remagnetizaciones por enterramiento. El caso de la Cuenca turbidítica de Jaca (Pirineos occidentales).

X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - GasteizLas remagnetizaciones químicas regionales relacionadas con procesos de enterramiento y diagénesis son un proceso ampliamente extendido en cuñas orogénicas y cuencas sedimentarias. Este proceso conlleva la neoformación autigénica de minerales ferromagnéticos s.l. en relación con el aumento de temperatura asociado al enterramiento. Sin embargo, todavía no se conoce bien la cinética de estos procesos, debido en parte a que la mayoría de las remagnetizaciones de este tipo descritas en la literatura científica se produjeron durante supercrones magnéticos. Los materiales turbidíticos eocenos de la Cuenca de Jaca (Pirineos Occidentales) muestran una remagnetización química de doble polaridad, registrando varios crones a lo largo de la secuencia sedimentaria remagnetizada. Dentro del proyecto UKRIA4D (PID2019-104693GB-I00/CTA), se va a realizar un estudio multidisciplinar para relacionar temperatura de enterramiento, mineralogía magnética y edad de la remagnetización con la que evaluar de manera empírica las relaciones cinéticas entre los distintos factores

Astronomical Handbooks and Tables from the Islamic World (750-1900): an Interim Report

The purpose of this paper is to present an overview of the current state of research on the medieval Islamic astronomical handbook known as zijes in particular, and astronomical tables in general