Origin, ore forming fluid evolution and timing of the Logrosán Sn-(W) ore deposits (Central Iberian Zone, Spain)

The Logrosán Sn–(W) ore deposits in the metallogenic Sn–W province of the European Variscan Belt consist of endo- and exogranitic greisen-type and quartz–cassiterite veins associated with a S-type granite. Mineral characterization, fluid inclusion study, isotope geochemistry and Ar–Ar geochronology have been combined in order to reconstruct the conditions for Sn–(W) mineralization. The endo- and exogranitic mineralization must have been developed in a relatively long-lived system (~ 308–303 Ma), during or soon after the emplacement of the Logrosán related-granite (at ca. 308 Ma). The mineralizing fluids are characterized by complex aqueous and volatile (H2O–N2–CO2–CH4–NaCl) fluid inclusions. Microthermometry and Raman analyses indicate that fluid composition evolved from N2–CH4 to N2-rich, followed by CO2-rich fluids, with varying amounts of H2O. The presence of N2 and CH4 suggests the interaction with fluids derived from the nearby metasedimentary host rocks. A model of host-rock interaction, assimilation, and mixing of metamorphic and magmatic fluids, resulting in change of the redox conditions, is proposed for tin deposition. Later sulfide minerals were precipitated as a result of pressure and temperature release

Hepcidin Response to Exercise: A Review.

Given the multiple functions of iron in the body, any state of iron deficiency will induce a series of secondary effects that could compromise sports performance. Low serum iron levels are commonly observed in athletes during the course of a training period, especially in those performing aerobic exercises and resistance training. Sometimes, body iron levels will even fall below those detected in sedentary individuals, and we could go as far as to say that iron deficiency is the most frequently observed nutrition disorder among athletes of any sport. Hepcidin, a hormone secreted by hepatocytes whose principal mechanism of action is the degradation of ferroportin (the main iron exporter from macrophages and the basolateral membrane of duodenal enterocytes), has been proposed as the main regulator of the body’s iron reserves. Thus, elevated serum hepcidin levels lead to diminished iron absorption and recycling, while lower levels of the hormone will cause greater iron absorption. Among the factors that affect the hepcidin response produced, we should highlight an individual’s total iron levels, erythropoietic demands, state of hypoxia, dietary iron, inflammation and physical exercise. Given the important role played by iron regulatory mechanisms in physical performance, this report reviews our current understanding of the physiological response of hepcidin to different sports intensities and modalities.post-print98 K

Effects of age, sex, sweat rate and environmental conditions on heart rate and perceived exertion in indoor cycling.

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Effects of active vs. passive interset rest among physiological and perceptual outcomes in bench press exercise.

Objectives The aim of this study was to compare the effects between 2-min active and 2-min passive interset rest among intra and interset velocity and power loss, blood lactate level, and effort perception in young resistance-trained male during bench press exercise. Equipment and methods Nineteen volunteers completed a maximal power test for bench press to determine the optimal load for maximum power production. Separated by, unless, 72 hours all participants realised two resistance training bouts consisting of 2 × 8 repetitions at maximal velocity using the optimal load for maximal power, and a 3rd set until muscle failure, with 2-min interset rest passive or active, where participants completed repetitions in vertical chest press at a controlled velocity during active protocol. We measured power and velocity for each repetition using a lineal encoder, and we calculate intraset loss for both outcomes with two different equations. We also measured blood lactate levels and rate of perceived exertion before and after each set, and during recovery period after the last set. Results There was a lower intraset velocity and power loss for active interset rest compared to passive, being these differences statistically significant for the 1st set (P < 0.05) as confirmed by Student's t-test for independent measures. We also found only for the passive protocol a significant increase in blood lactate levels when comparing the values post set and before the consecutive set (P < 0.01), showing a significant increase during the interset rest period (post-set 1–pre-set 2; and post-set 2–pre-set 3). Moreover, blood lactate levels were significantly higher in passive compared to active before starting the 3rd set (P < 0.05). There were no significant differences for rate of perceived exertion between both protocols.pre-print430 K

Heart rate recovery normality data recorded in response to a maximal exercise test in physically active men.

Background. Despite a growing clinical interest in determining the heart rate recovery (HRR) response to exercise, the limits of a normal HRR have not yet been well established. Purpose. This study was designed to examine HRR following a controlled maximal exercise test in healthy, physically active adult men. Methods. The subjects recruited (n=789) performed a maximal stress test on a treadmill. HRR indices were calculated by subtracting the 1st and 3rd minute heart rates during recovery from the maximal heart rate obtained during stress testing and designated these as HRR-1 and HRR-3, respectively. The relative change in HRR was determined as the decrease in HR produced at the time points 1 min and 3 min after exercise as a percentage of the peak HR (%HRR-1/HRpeak and %HRR-3/HRpeak, respectively). Percentile values of HRR-1 and HRR-3 were generated for the study population. Results. Mean HHR-1 and HHR-3 were 15.24±8.36 bpm and 64.58±12.17 bpm, respectively and %HRR-1/HRpeak and %HRR-3/HRpeak were 8.60±4.70% and 36.35±6.79%, respectively. Significant correlation was detected between Peak VO2 and HRR-3 (r=0.36; p<0.001) or %HRR-3/HRpeak (r=0.23; p<0.001). Conclusions. Our study provides normality data for heart rate recovery following a maximal ergometry test obtained in a large population of physically active men.pre-print166 K

OOFDM signal transmission using a single optical broadband source

[EN] In this letter, optical OFDM signal transmission is demonstrated by using a broadband optical source over a 10 km fiber link. OFDM signal transmission usually employs lasers to generate the optical carrier since the chromatic fiber dispersion prevents the use of broadband optical sources. However, an interferometric system is introduced to allow signal transmission at a given RF band when a broadband optical source is employed. Optical sources with different optical bandwidths have been employed to explore the limitations of the system. OFDM transmission at 2 Gb/s using both QPSK and 16QAM modulation is demonstrated over 10 km.This work was supported in part by the National Project MINECO under Grant TEC2014-60378-C2-1-R MEMES and in part the Regional GVA funded Prometeo 2013/012 Project on Next Generation Microwave Photonic technologies.Chicharro López, FI.; Ortega Tamarit, B.; Diego Antón, MD.; Mora Almerich, J. (2017). OOFDM signal transmission using a single optical broadband source. IEEE Photonics Technology Letters. 29(7):563-566. https://doi.org/10.1109/LPT.2017.2668464S56356629

Broadband optical sources for low-cost WDM-MB-OFDM networks

[EN] Multiband OFDM signal transmission through a 10 km optical fiber link is experimentally demonstrated by using a broadband source. We propose the use of optical broadband sources in multiband OFDM signal transmitters as a low-cost and power fading free solution. The OFDM band is dynamically selected in the receiver by means of an MZI. Therefore, MB-OFDM is demonstrated at 1.5 Gb/s per band in access networks, supporting up to 20 ONUs.Chicharro López, FI.; Ortega Tamarit, B.; Diego Antón, MD.; Mora Almerich, J. (2017). Broadband optical sources for low-cost WDM-MB-OFDM networks. IEEE Communications Letters. 21(8):1759-1762. doi:10.1109/LCOMM.2017.2702175S1759176221

Efectos de la recuperación activa versus pasiva en press de banca.

La recuperación entre series en ejercicios de fuerza es una de las variables de las que depende el rendimiento físico y sobre la que no se ha investigado demasiado. La mayoría de las investigaciones al respecto se han centrado en el estudio de diferentes intervalos de recuperación, es decir, en la variable duración; sin embargo, nuestro objetivo es analizar si la recuperación activa podría minimizar la pérdida de potencia en comparación con la recuperación pasiva tradicional, manteniendo la duración constante entre ambos protocolos. Para ello, 14 voluntarios jóvenes entrenados realizaron dos series de ocho repeticiones y una tercera serie hasta el fallo muscular en press de banca con la carga óptima para el desarrollo de la potencia máxima separando cada serie con dos minutos de recuperación pasiva, sin actividad, o activa, realizando 60 segundos de press vertical de pecho a una velocidad de ejecución lenta y con una carga baja. La recuperación activa logró que la pérdida de potencia intraseries fuera menor en comparación con la recuperación pasiva, siendo esta diferencia estadísticamente significativa en la primera y la tercera serie (13.34% vs. 18.84%, p=.006; y 13.38% vs. 17.53%, p=.001; respectivamente). Además, observamos una discreta pero significativa mayor percepción del esfuerzo en la segunda serie (4.5 vs. 5.0, p=.033). En conclusión, la recuperación activa podría ser un estímulo adecuado para minimizar la pérdida del rendimiento intrasesión y mejorar la percepción del esfuerzo en ejercicios de fuerza.post-print354 K

Zircon U-Pb and Hf isotopic constraints on the genesis of a post-kinematic S-type Variscan tin granite: the Logrosán cupola (Central Iberian Zone)

The Variscan orogeny produced widespread granites along the European Variscan belt. In relation to crustal thickening, post-collisional multiple tin-bearing highly fractionated S-type leucogranites were emplaced. The Logrosán granite represents one of those granitic bodies and is a focus of this study. The Logrosán granite is located in the Central Extremadura Batholith (CEB), within the Central Iberian Zone (CIZ) and was emplaced during post kinematic stages of the Variscan orogeny at ca. 308 Ma, as determined by combined ID-TIMS U–Pb and LA-ICPMS geochronology. The granitic body intruded the metasedimentary Schist Greywacke Complex (SGC) of Neoproterozoic age. A moderately evolved medium- to coarse-grained two mica leucogranite (Main unit) and some highly evolved aplitic or microporphyritic units (evolved units) are distinguishable on the basis of their petrography and whole rock geochemistry.  Initial 87Sr/86Sr ratios vary from 0.7134 to 0.7311, whereas initial εNd shows a restricted range from -4.3 to -4.0 and εHf(t) ranges from  +2.0 to -4.6 for Variscan-age zircons. Inherited zircons exhibit mostly Neoproterozoic ages and juvenile Hf-isotope composition (eHf up to +14.6), analogous to that of zircons from the SGC metasediments. The available geological, geochronological, geochemical and isotopic data allow to propose the partial melting of heterogeneous Neoproterozoic metasedimentary material, similar to the outcropping SGC, for the genesis of the Logrosán granite.La orogenia Varisca produjo una gran cantidad de granitos a lo largo del Cinturón Varisco Europeo. En relación con el engrosamiento cortical se emplazaron tardíamente granitos de tipo-S, muy fraccionados y ricos en Sn. El presente estudio se centra en uno de esos cuerpos graníticos, el granito de Logrosán. El plutón de Logrosán forma parte del Batolito de Extremadura Central (BEC), en la Zona Centroibérica (ZCI), y se emplazó durante las etapas tardías de la orogenia Varisca, a los ca. 308 Ma, según los datos combinados de geocronología de U-Pb por ID-TIMS y por LA-ICPMS. El cuerpo granítico intruyó los metasedimentos del Complejo Esquisto Grauváquico (CEG) de edad fundamentalmente Neoproterozoica. En el plutón se distinguen, de acuerdo a la petrografía y a la geoquímica de roca total, un leucogranito de dos micas de tamaño de grano medio-grueso moderadamente evolucionado (Main Unit) y varias unidades aplíticas o microporfídicas altamente evolucionadas (Evolved Units). Las relaciones isotópicas iniciales de 87Sr/86Sr varían de 0.7125 a 0.7286, mientras que el εNd inicial muestra un rango restringido de -4.3 a -4.0 y el εHf(t) en circones variscos oscila de +5.7 a -10.5. Los circones heredados del granito de Logrosán muestran edades principalmente Neoproterozoicas y composiciones isotópicas de Hf juveniles (εHf &gt; +14.7), análogas a las encontradas en los circones del CEG. Los datos geológicos, geoquímicos, geocronológicos e isotópicos de los que se dispone sugieren que el granito de Logrosán se originó por la fusión parcial de materiales metasedimentarios Neoproterozoicos similares a los del CEG

Upper extremity deep vein thrombosis in a triathlete: Again intense endurance exercise as a thrombogenic risk.

Triathlon followers increase each year and long-distance events have seen major growth worldwide. In the cycling phase, athletes must maintain an aerodynamic posture on the bike for long periods of time. We report a case of a 38-year-old triathlete with symptoms of an axillary vein thrombosis 48 h after a long triathlon competition. After 3 days of hospitalizationwith a treatment consisted on enoxaparin anticoagulant and acenocumarol, the patient was discharged with instructions to continue treatment under home hospitalization with acetaminophen. Four weeks after the process, the patient was asymptomatic and the diameter of his armwas near normality. Due to the growing popularity of events based on endurance exercise, it is necessary more research to determine the etiopathogeny of deep venous thrombosis in athletes.pre-print274 K