Search results for "Planetary Science"

In-flight calibration of the ROSAT HRI ultraviolet sensitivity

2000

Comparing measured and estimated count rates of a few selected sample stars, we confirm the validity and provide the in-flight calibration of the ROSAT HRI UV/visible effective area model in Zombeck et al. The count rate estimates for Betelgeuse derived with this model are in agreement with the measured HRI upper limit. This result is also confirmed in an erratum by Berghöfer et al. aimed at revising their previous calculation, which was overestimated by more than 2 orders of magnitude. Adopting this ROSAT HRI UV/visible effective area model and measured UV/visible spectra of a set of sample stars covering the range of Teff 3000-40,000 K, we have built the calibration curves to estimate UV/…

L'impacte d'Helene Deutsch: Psicologia de les dones, en l'àmbit feminista

2016

espanolEn este trabajo se ha analizado la obra de Helene Deutsch The psychology of women, con el objetivo de conocer su influencia en la Psicologia de la mujer. Asi por medio de una metodologia bibliometrica se ha elaborado una base de datos bibliograficos a partir del Social Sciences Citation Index (1956-2005). Los resultados indican que este libro ha sido citado un considerable numero de veces, lo cual muestra el impacto de la aproximacion psicoanalitica en el campo feminista. Los autores que mas lo citan pertenecen a aquella aproximacion psicoanalitica, a la Psicologia del desarrollo y al ambito feminista. Y entre las revistas, abundan las psicoanaliticas. Asimismo, los autores mas citad…

Bibliometric analysis of publications by South African viticulture and oenology research centres

2012

We analysed the production, impact factor of, and scientific collaboration involved in viticulture and oenology articles associated with South African research centres published in international journals during the period 1990–2009. The articles under scrutiny were obtained from the Science Citation Index database, accessed via the Web of Knowledge platform. The search strategy employed specific viticulture and oenology terms and was restricted to the field ‘topic’. The results showed that 406 articles were published during the review period, with the most number of publications being in the South African Journal of Enology and Viticulture (n = 34), American Journal of Enology and Vit…

Uncertainty on w from large-scale structure

2012

We find that if we live at the center of an inhomogeneity with total density contrast of roughly 0.1, dark energy is not a cosmological constant at 95% confidence level. Observational constraints on the equation of state of dark energy, w, depend strongly on the local matter density around the observer. We model the local inhomogeneity with an exact spherically symmetric solution which features a pressureless matter component and a dark-energy fluid with constant equation of state and negligible sound speed, that reaches a homogeneous solution at finite radius. We fit this model to observations of the local expansion rate, distant supernovae and the cosmic microwave background. We conclude …

Big Data Processing in the ATLAS Experiment: Use Cases and Experience

2015

Abstract The physics goals of the next Large Hadron Collider run include high precision tests of the Standard Model and searches for new physics. These goals require detailed comparison of data with computational models simulating the expected data behavior. To highlight the role which modeling and simulation plays in future scientific discovery, we report on use cases and experience with a unified system built to process both real and simulated data of growing volume and variety.

Beta-galactosidase activity assay for yeast

2019

Freshwater organisms that build stromatolites: a synopsis of biocrystallization by prokaryotic and eukaryotic algae

1998

In freshwater environments such as river and stream bottoms, rocks and submerged vegetation are covered with a biological felt (also called a periphyton, microbial mat, biofilm, etc.) that is susceptible to calcification. Compilation of an extensive bibliography and our own observations have allowed the identification of 44 species of Coccogonophyceae, 122 Hormogonophyceae, 2 Chrysophyceae, 35 Chlorophyceae, 3 Xanthophyceae, 2 diatoms, and 3 Rhodophyceae that grow on calcareous tufa and coat vegetation. Diverse genera include species that are also calcified but impossible to determine because they lack reproductive organs. Crystals have been described from 74 species in the literature and w…

Storage and release of fossil organic carbon related to weathering of sedimentary rocks

2007

International audience; The biogeochemical carbon cycle, which plays an undeniable role in global climate change, is defined both by the size of carbon reservoirs (such as the atmosphere, biomass, soil and bedrock) and the exchange between them of various mineral and organic carbon forms. Among these carbon forms, fossil organic carbon (FOC) (i.e., the ancient organic matter stored in sedimentary rocks) is widely observed in modern environments but is not included in the supergene carbon budget. Using a digitized map of the world and an existing model of CO2 consumption associated with rock weathering, we establish the global distribution of FOC stored in the first meter of sedimentary rock…

2016

Rivers carry large amounts of dissolved organic matter (DOM) to the oceans thereby connecting terrestrial and marine element cycles. Photo-degradation in conjunction with microbial turnover is considered a major pathway by which terrigenous DOM is decomposed. To reveal globally relevant patterns behind this process, we performed photo-degradation experiments and year-long bio-assays on DOM from ten of the largest world rivers that collectively account for more than one-third of the fresh water discharge to the global ocean. We furthermore tested the hypothesis that the terrigenous component in deep ocean DOM may be far higher than biomarker studies suggest, because of the selective photoche…

Retrieval and assessment of CO2 uptake by mediterranean ecosystems using remote sensing and

2014

Photosynthesis is a process by which carbon and energy enter ecosystems. The knowledge of where,when, and how carbon dioxide (CO2) is exchanged between terrestrial ecosystems and atmosphere is crucial to close the Earth's carbon budget and predict feedbacks in a likely warming climate. Gross photosynthesis (uptake of CO2) by vegetation is responsible for the gross primary production (GPP) of the ecosystem. Normally GPP refers to the sum of the photosynthesis by all leaves measured at the ecosystem scale. John Monteith proposed in 1972 a simple approach that has become the paradigm for understanding GPP. It considers GPP as proportional to the incident short wave radiation (PAR), the fractio…