The origin of carbon isotope vital effects in coccolith calcite

Calcite microfossils are widely used to study climate and oceanography in Earth’s geological past. Coccoliths, readily preserved calcite plates produced by a group of single-celled surface-ocean dwelling algae called coccolithophores, have formed a significant fraction of marine sediments since the Late Triassic. However, unlike the shells of foraminifera, their zooplankton counterparts, coccoliths remain underused in palaeo-reconstructions. Precipitated in an intracellular chemical and isotopic microenvironment, coccolith calcite exhibits large and enigmatic departures from the isotopic composition of abiogenic calcite, known as vital effects. Here we show that the calcification to carbon fixation ratio determines whether coccolith calcite is isotopically heavier or lighter than abiogenic calcite, and that the size of the deviation is determined by the degree of carbon utilization. We discuss the theoretical potential for, and current limitations of, coccolith-based CO2 paleobarometry, that may eventually facilitate use of the ubiquitous and geologically extensive sedimentary archive

Constraints on the vital effect in coccolithophore and dinoflagellate calcite by oxygen isotopic modification of seawater

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 141 (2014): 612-627, doi:10.1016/j.gca.2014.05.002.In this study, we show that there are independent controls of 18O/16O and 13C/12C fractionation in coccolithophore and dinoflagellate calcite due to the contrasting kinetics of each isotope system. We demonstrate that the direction and magnitude of the oxygen isotope fractionation with respect to equilibrium is related to the balance between calcification rate and the replenishment of the internal pool of dissolved inorganic carbon (DIC). As such, in fast growing cells, such as those of Emiliania huxleyi and Gephyrocapsa oceanica (forming the so-called “heavy group”), calcification of the internal carbon pool occurs faster than complete isotopic re-adjustment of the internal DIC pool with H2O molecules. Hence, coccoliths reflect the heavy oxygen isotope signature of the CO2 overprinting the whole DIC pool. Conversely, in large and slow growing cells, such as Coccolithus pelagicus ssp. braarudii, complete re-equilibration is achieved due to limited influx of CO2 leading to coccoliths that are precipitated in conditions close to isotopic equilibrium (“equilibrium group”). Species exhibiting the most negative oxygen isotope composition, such as Calcidiscus leptoporus (“light group”), precipitate coccolith under increased pH in the coccolith vesicle, as previously documented by the “carbonate ion effect”. We suggest that, for the carbon isotope system, any observed deviation from isotopic equilibrium is only “apparent”, as the carbon isotopic composition in coccolith calcite is controlled by a Rayleigh fractionation originating from preferential incorporation of 12C into organic matter. Therefore, species with low PIC/POC ratios as E. huxleyi and G. oceanica are shifted towards positive carbon isotope values as a result of predominant carbon fixation into the organic matter. By contrast, cells with higher PIC/POC as C. braarudii and C. leptoporus maintain, to some extent, the original negative isotopic composition of the CO2. The calcareous dinoflagellate Thoracosphaera heimii exhibits different behaviour for both isotopic systems, in particular with respect to its very negative carbon isotope composition, owing to coeval intra and extracellular biomineralisation in this group. In this study, we also investigate the sensitivity of 18O/16O fractionation to varying ambient oxygen isotope composition of the medium for inorganic, coccolithophore, and dinoflagellate calcite precipitated under controlled laboratory conditions. The varying responses of different taxa to increased oxygen isotope composition of the growth medium may point to a potential bias in sea surface temperature reconstructions that are based on the oxygen isotopic compositions of sedimentary calcite, especially during times of changing seawater oxygen isotopic composition. Overall, this study represent an important step towards establishing a mechanistic understanding of the “vital effect” in coccolith and dinoflagellate calcite, and provides valuable information for interpreting the geochemistry of the calcareous nannofossils in the sedimentary record, at both monospecific and interspecies levels.MH is grateful to the Natural Environment Research Council (NERC) for funding through Postdoctoral Fellowship (NE/H015523/1). TJH is supported by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Doherty Foundation. REMR was supported through European Research Council (ERC) grant SP2-GA-2008-200915

Estudio epizootiológico de las dermatofitosis en perros y gatos

Se ha investigado la etiología de 141 casos de dermatitis en las especies canina (121 casos) y felina (17 casos). Mediante procedimientos dermatológicos de rutina, se comprobó la etiología micótica de veintisiete de ellos, encontrando una incidencia superior en gatos (58,82%) que en perros (13,71%). Las formas clínicas implicadas fueron: anular (60%), fávica (24%), kerion (12%) y onicomicosis (4%), no presentando una zona corporal específica de localización.A study was made of the aetiology of 141 cases of dermatitis in dogs (121 cases) and cats (17 cases). Rutine dermatological procedures revealed a mycotic aetiology in 27 animals, though it was more prevalent in cats (58,82%) than in dogs (13, 71%). Tbe clinicalforms involved uiere. annular (60%), favic (24%), kerion (12%) and onicomycosis (4%). No specific body site in the body was determined

Diferencias cinemáticas entre el revés a una y dos manos de tenis usando giróscopos. Un estudio exploratorio

The main objective of this article is to compare angular kinematics and intersegmental coordination of the upper limbs between one-handed and two handed backhands in a sample of 20 male competition players by using gyroscopes and compare ball speeds and accuracy obtained in both types of backhands. The angular kinematics, intersegmental coordination, ball speed and accuracy were compared during a specific stroke performance test using four inertial sensors (trunk, head, arm and forearm). We hypothesize that there will be significant differences in terms of ωpeak and intersegmental coordination in some of the segments measured between DH and SH by using gyroscopes, but the opposite will happen in the variables speed ball and accuracy. There are no significant differences between one-handed backhand and two-handed backhand in terms of speed and accuracy. Higher peaks angular speeds were found in the trunk and arm over the x axis in two-handed backhand which could indicate that this type of backhand generates greater trunk rotation and external rotation of the arm and forearm compared to one-handed backhand. The peak angular speeds were greater in the arm and forearm on the z axis in the case of one-handed backhand which is related to a greater extension of the forearm accompanied by a higher termination in the technical gesture. In conclusion, the proposed model of biomechanical analysis through the use of gyroscopes is especially useful for kinematic analysis of tennis strokes during field-based experimentation and could easily be adapted to other sports. It is also a low-cost and portable alternative that includes all instrumentation and data processing.El objetivo principal del presente estudio es comparar la cinemática angular y la coordinación intersegmentaria del tren superior entre el revés a una y dos manos de tenis en una muestra de 20 jugadores de nivel competición mediante el uso de giróscopos, y comparar las velocidades de pelota y la precisión obtenidas en ambos tipos de revés. La cinemática angular, la coordinación intersegmentaria, la velocidad de pelota y la precisión se obtuvieron de cada jugador mediante una prueba de golpeo realizada con cuatro sensores inerciales colocados (tronco, cabeza, brazo y antebrazo). Se sostiene la hipótesis de que se encontraran diferencias significativas en términos de ωpico y coordinación intersegmentaria en alguno de los segmentos intervinientes en el revés a una y dos manos, pero sucederá lo contrario en las variables velocidad de pelota y precisión. Tras el análisis de los resultados, no se encontraron diferencias significativas entre el revés a una y dos manos en velocidad de pelota y precisión. Sin embargo, se encontraron velocidades angulares pico significativamente más altas en el tronco y brazo sobre el eje x en el revés a dos manos, lo que podría indicar que este tipo de revés genera una rotación de tronco y una rotación externa de brazo y antebrazo mayores que las del revés a una mano. Las velocidades angulares pico fueron significativamente mayores en el brazo y antebrazo sobre el eje z en el caso del revés a una mano, lo cual está relacionado con una mayor extensión del antebrazo acompañada de una terminación más alta del gesto técnico. En conclusión, el modelo propuesto de análisis biomecánico a través del uso de giróscopos es especialmente útil para el análisis cinemático de los golpes de tenis en estudios de campo y podría adaptarse fácilmente a otros deportes, suponiendo una alternativa portable y de bajo coste que además incluye toda la instrumentación y procesamiento de los datos

Nursery location and potassium enrichment in Aleppo pine stock 1. Effect on nursery culture, growth, allometry and seedling quality

There is a need for a better understanding of the primary role of macronutrients in Aleppo pine stock quality and for producing larger nutrient-loaded stock, which may be challenging for inland nurseries. The influence of nursery location and fertilization on nursery culture, growth, allometry and seedling quality of Aleppo pine was studied in seedlings cultivated over the 2006 growing year. Fertilization treatments considered how a K enrichment performed over common programs currently being practiced and divided into three levels of K/N ratio: 0.63-0.89 (normal), 1.81-1.89 (high), and 2.25-2.53 (very high). Results showed that fertilization had a minor effect on seedling growth and allometry in comparison with location, which was the governing factor. However, fertilizing treatments significantly affected final seedling attributes, which has its origin on the early treatment differences that were kept up to the end of culture. Higher nutrient supply treatments produced the highest nutrient concentration in seedlings but they were associated with lower fertilization efficiencies. Fertilizer efficiency was approximately twofold in the coastal nursery for the three macronutrients, although concentration was higher in the inland nursery due to lower seedling growth. It is concluded that warmer regions are more suitable for producing large stock more efficiently. © Institute of Chartered Foresters, 2011. All rights reserved.This work was supported by the projects 'Improvement of reforestation in the province of Valencia through the definition of seedling quality standards' (20020995) and 'Establishment of protocols for seedling quality testing in nursery and field' (20080682), directed by the Polytechnic University of Valencia and the Valencian Regional Government (Generalitat Valenciana).Campo García, ADD.; Hermoso De Mena, J.; Ceacero, CJ.; Navarro Cerrillo, RM. (2011). Nursery location and potassium enrichment in Aleppo pine stock 1. Effect on nursery culture, growth, allometry and seedling quality. Forestry. 84(3):221-233. https://doi.org/10.1093/forestry/cpr008S22123384

RunScribe Sacral Gait Lab™ Validation for Measuring Pelvic Kinematics during Human Locomotion at Different Speeds

Optoelectronic motion capture systems are considered the gold standard for measuring walking and running kinematics parameters. However, these systems prerequisites are not feasible for practitioners as they entail a laboratory environment and time to process and calculate the data. Therefore, this study aims to evaluate the validity of the three-sensor RunScribe Sacral Gait Lab™ inertial measurement unit (IMU) in measuring pelvic kinematics in terms of vertical oscillation, tilt, obliquity, rotational range of motion, and the maximum angular rates during walking and running on a treadmill. Pelvic kinematic parameters were measured simultaneously using an eight-camera motion analysis system (Qualisys Medical AB, GÖTEBORG, Sweden) and the three-sensor RunScribe Sacral Gait Lab™ (Scribe Lab. Inc. San Francisco, CA, USA) in a sample of 16 healthy young adults. An acceptable level of agreement was considered if the following criteria were met: low bias and SEE ( 0.90), and good reliability (ICC > 0.81). The results obtained reveal that the three-sensor RunScribe Sacral Gait Lab™ IMU did not reach the validity criteria established for any of the variables and velocities tested. The results obtained therefore show significant differences between the systems for the pelvic kinematic parameters measured during both walking and runningThe State Research Agency (SRA)The European Regional Development Fund (ERDF) with the project EDUSPORT (REF: PID2020-115600RB-C21

Estudio clínico morfológico de la deformación del borde dorsal del cuello del burro de raza andaluza

The aim of this study was to a clinical, morphological of deformation dorsal neck edge on donkeys Andalusian in Bodonal de la Sierra, Extremadura, Spain. We studied a total of 31 donkeys. Clinical examination was performed and morphological considering weight and body condition was measured cervical perimeter. Deformation of the dorsal edge of the neck in all cases studied was evident. Morphological study was to consider the deformation of the dorsal edge of the neck considering the crest of the neck (score of 1 to 5) evidenced. 0 and 1 score-no donkey under these categories. Score 2 - 42 % Score. 3 - 32% score. 4 - 3 % and score 5 - 23%. The statistical results of the peso versus the cervical neck circumference showed a correlation coefficient of 0.773 and the score grade obese neck and body condition was 0.240. In conclusion lesions consistent with deformation of the dorsal edge of the neck in Andalusian breed donkeys were observed.Se plantea como objetivo un estudio clínico morfológico de la deformación del borde dorsal del cuello en burros de raza Andaluza en Bodonal de la Sierra, Extremadura-España. Fueron estudiados un total de 31 burros. Se practicó un examen clínico y morfológico considerando condición corporal peso y se midió el perímetro cervical. Se evidenció deformación del borde dorsal del cuello en todos los casos estudiados. El estudio morfológico para considerar la deformación del borde dorsal del cuello considerando la cresta de la nuca (puntuación del 1 al 5) evidencio: para Puntuación 0 y 1.- ningún burro bajo estas categorías. Puntuación 2.- 42%, Puntuación 3.- 32%, Puntuación 4.- 3% y Puntuación 5.- 23%. Los resultados estadísticos del peso versus el perímetro cervical del cuello presentaron un coeficiente de correlación de 0.773 y para el grado puntuación del cuello obeso y condición corporal fue de 0.240. En conclusión se observaron lesiones compatibles con la deformación del borde dorsal del cuello en burros de raza Andaluza