Search results for "Excursion"
showing 10 items of 33 documents
Detailed record of the mid-Oxfordian (Late Jurassic) positive carbon-isotope excursion in two hemipelagic sections (France and Switzerland): A plate …
2007
14 pages; International audience; The Oxfordian (Late Jurassic) was a time of widespread change in Jurassic marine (carbonate) sedimentation patterns. A marked positive excursion in δ13C is dated as Middle Oxfordian in age. In this study we investigate if changes in carbonate sedimentation coincided with altered carbon cycling and climate. We use C-isotope records as a proxy for the evolution of the carbon cycle and compare δ13C-trends with the evolution of sedimentation in a segment of the opening Tethys seaway. One of the studied sections is located in the Subalpine basin of France (Trescléoux and Oze), the other in the Swiss Jura mountains (Liesberg). Carbon-isotope stratigraphy of carbo…
The Valanginian isotope event: a complex suite of palaeoenvironmental perturbations.
2011
17 pages; International audience; The Valanginian records a severe crisis of carbonate systems, both on platforms and in the pelagic realm. This crisis is roughly concomitant with the Weissert Event, characterized by a positive δ13C excursion of about 2‰in marine carbonates. However, it is unclear if the response of these two carbonate systems to the global perturbations is contemporaneous, or if they react differently. For this purpose, accumulation rates of pelagic carbonates produced by nannofossils and of platform-derived carbonates have been quantified in a hemipelagic environment (the Vocontian Basin, SE France) that has the potential to record the reaction of both shallow-water and p…
La Institución Libre de Enseñanza como iniciadora de la Educación Patrimonial en España
2012
El objetivo principal de este trabajo es mostrar y la vez reivindicar el papel de la Institución Libre de Enseñanza como el primer centro educativo en España que otorgaba una importancia fundamental a la Educación Patrimonial. De esta manera, entre las actividades que se llevaban a cabo podemos encontrar tanto excursiones a museos y sitios históricos como a espacios naturales, con el afán de que los alumnos consideraran lo visitado como una seña de identidad propia. Pero con esta presentación también queremos conseguir hacer comprender al público que la Educación Patrimonial es de gran valor porque del conocimiento del patrimonio surge una identificación con él, que conlleva al interés por …
Paleoclimate variability during the Blake geomagnetic excursion (MIS 5d) deduced from a speleothem record
2014
To evaluate possible connections between climate and the Earth's magnetic field, we examine paleoclimate proxies in a stalagmite (PA-8) recording the Blake excursion (∼112–∼116.4 ka) from Cobre cave (N Spain). Trace element, δ13C, δ18O, δ234U, fluorescent lamination, growth rate, and paleomagnetic records were synchronized using a floating lamina-counted chronology constrained by U–Th dates, providing a high-resolution multi-proxy paleoclimate record for MIS 5d. The alpine cave setting and the combination of proxies contributed to improve the confidence of the paleoclimatic interpretation. Periods of relatively warm and humid climate likely favored forest development and resulted in high sp…
Glycemic Variability Assessment with a 14-Day Continuous Glucose Monitoring System: When and How Long to Measure MAGE (Mean Amplitude of Glucose Excu…
2021
Mean amplitude of glucose excursion (MAGE) is considered as the “gold standard” for assessing the short-term within-day glycemic variability (GV), which is an important component of overall glycemic control. A 14-day continuous glucose monitoring system is now widely used and allows easier assessment of GV. However, it is still unknown whether MAGE, usually calculated on a 48-hour period is identical whatever the time during the 14-day lifespan of the sensor and whether a longer time period might give additional information. We evaluated in 68 patients with type 1 diabetes, MAGE during three 2-day periods (day1-day3; day6-day8; day11-day13) and during periods of 3 days and 4 days. MAGE cal…
Extension of The Stochastic Differential Calculus To Complex Processes
1996
In structural engineering complex processes arise to predict the first excursion failure, fatigue failure, etc. Indeed to solve these problems the envelope function, which is the modulus of a complex process, is usually introduced. In this paper the statistics of the complex response process related to the envelope statistics of linear systems subjected to parametric stationary normal white noise input are evaluated by using extensively the properties of stochastic differential calculus.
‘Tour me onshore’: understanding cruise tourists’ evaluation of shore excursions through text mining
2018
ABSTRACTThe aim of this paper is to shed light on the elements underlying cruise tourists’ evaluation of shore excursions, approaching them as an interaction of expressive and instrumental components.To fulfil the aim of the investigation, a thematic content analysis of 1296 online reviews was conducted using the text-mining software Leximancer. The results of the study revealed that cruise visitors with different overall satisfaction with their guided tour focus the narrative of their opinion on different tour attributes. Thus, the dominant themes of the cruise passengers delighted with their tour included the performance of the tour guide, the arrangement of the tour, as well as the cruis…
Authenticity in Extra-curricular Mathematics Activities: Researching Authenticity as a Social Construct
2015
In this chapter I study authentic aspects in mathematics education, in particular with respect to mathematical modelling. I define ‘authenticity’ as a social construct, building on the French sociologist Emile Durkheim. For an aspect to be authentic, it needs to have: (1) an out-of-school origin and (2) a certification of originality. The study validates this definition, asking: what authentic aspects can be identified within mathematics education? Data were collected from the excursion Railway Timetable Dynamics. During the excursion secondary school students were exposed to research carried out by university mathematicians on behalf of the National Railway Company. The authentic aspects w…
Positive Sulfate Sulfur Isotope Excursion Indicates Large-Scale Pyrite Burial and Marine Anoxia during the End–Triassic Mass Extinction
2020
The late Rhaetian–early Hettangian transition is characterised by the emplacement of Central Atlantic magmatic province and associated climatic effects, coincident with a severe biotic crisis (~201.5 Ma). The oxygen deficiency in the ocean realm is possibly linked to this significant loss in marine biodiversity. However, direct evidence of contemporaneous development of marine anoxia on a global scale has been lacking and the relationship between oxygen and extinction is unclear. Here we report carbonate-associated sulfate δ34S data from three sections across the Late Triassic–Early Jurassic transition. We find synchronous large positive δ34S shifts with a magnitude of >10‰ in the latest…
Geochemical and sedimentological evidence of productivity cycles recorded in Toarcian black shales from the Belluno Basin, Southern Alps, northern It…
1999
ABSTRACT Organic-carbon-rich black shales cyclically alternating with bioturbated limestones and gray marlstones, which crop out in the Belluno Trough (Southern Alps, Italy), are expression of the early Toarcian anoxic event in the Tethys basin. Sedimentological and geochemical features such as well-developed lamination, common very small ( A negative 13C excursion at the middle part of the studied interval is correlative to maxima in TOC, V/Rb, and Ba/Rb values, identifying, within the Toarcian anoxic event, a stage of more intense bottom-water anoxia coupled with high surface fertility.