Search results for "Planetary Science"
showing 10 items of 4367 documents
Monitoring barley and corn growth from remote sensing data at field scale
2004
Vegetation indices have been used for operational quantitative monitoring of vegetation. Here, corn and barley cultures have been used to relate meaningful biophysical parameters such as dry biomass and Crop Growth Rate (CGR) to the well-established Normalized Difference Vegetation Index (NDVI). We explain these relationships by means of the use of the Light Use Efficiency (LUE) models, based on the positive relation between primary production and Absorbed Photosynthetically Active Radiation (APAR). In these models we introduce NDVI as a linear estimator of f APAR. Experimental data over corn and barley show that dry biomass is linearly related to the Time-Integrated Value of the NDVI (TIND…
Distansescharella seguenzai Cipolla, 1921 (Bryozoa, Cheilostomata),nouvelles données morphologiques et écologiques tirées de spécimens fossiles (Mioc…
1989
The cribrimorph Distansescharella seguenzai Cipolla,,1921, described from the Pliocene of Sicily has been rediscovered in fossil deposits (Messinian of Western Algeria, and Lower Pliocene of Calabria, Southern Italy) and in Recent Mediterranean material (Straits of Gibraltar, Alboran Sea, Gulf of Tripoli). Its morphology is demonstrated by SEM study of living specimens. In spite of some differences with the type-species of Distansescharella D'Orbigny revealed by examination of its neotype, the generic status of D. seguenzai is confirmed. An ecological analysis of the Recent and fossil assemblages including D. seguenzai is made by considering the zoarial growth forms and the potential habita…
INTEGRAL/RXTE Observations of Cygnus X-1
2003
We present first results from contemporaneous observations of Cygnus X-1 with INTEGRAL and RXTE, made during INTEGRAL's performance verification phase in 2002 November and December. Consistent with earlier results, the 3-250 keV data are well described by Comptonization spectra from a Compton corona with a temperature of kT~50-90 keV and an optical depth of tau~1.0-1.3 plus reflection from a cold or mildly ionized slab with a covering factor of Omega/2pi~0.2-0.3. A soft excess below 10 keV, interpreted as emission from the accretion disk, is seen to decrease during the 1.5 months spanned by our observations. Our results indicate a remarkable consistency among the independently calibrated de…
The NHXM observatory
2011
Exploration of the X-ray sky has established X-ray astronomy as a fundamental astrophysical discipline. While our knowledge of the sky below 10 keV has increased dramatically (∼8 orders of magnitude) by use of grazing incidence optics, we still await a similar improvement above 10 keV, where to date only collimated instruments have been used. Also ripe for exploration is the field of X-ray polarimetry, an unused fundamental tool to understand the physics and morphology of X-ray sources. Here we present a novel mission, the New Hard X-ray Mission (NHXM) that brings together for the first time simultaneous high-sensitivity, hard-X-ray imaging, broadband spectroscopy and polarimetry. NHXM will…
Of Cockroaches and Symbionts: Recent Advances in the Characterization of the Relationship between Blattella germanica and Its Dual Symbiotic System
2022
This article belongs to the Collection Feature Review Papers for Life.
Determinants of Blockchain Technology Introduction in Organizations: an Empirical Study among Experienced Practitioners
2021
Abstract Blockchain is expected to enable new types of interorganizational relationships, new approaches to governance and new approaches to settlement and clearing processes. Neverthless, although the interest on blockchain is on the rise, there are not many blockchain implementations in organizations and there is limited empirical research investigating the reasons for this. This paper contributes to filling this gap by investigating the following research question: what are the impeding and motivating factors for organizational blockchain adoption? Data were collected through a survey based on pairwise comparisons of key factors identified in the literature. The data collected were analy…
Does Glycemic Control Modulate the Impairment of NLRP3 Inflammasome Activation in Type 2 Diabetes?
2019
Since mitochondrial dysfunction is associated with NOD-like receptor family protein 3 (NLRP3) activation in type 2 diabetes (T2D), which can eventually lead to an impaired immune response, we set out to determine if glycemic control modulates the effects of T2D on the NLRP3 inflammasome. We have studied leukocytes from 61 diabetic patients [25 with glycated hemoglobin (HbA(1c)) 7% and 36 with HbA(1c) 8%] and 40 healthy controls. Total and mitochondrial reactive oxygen species (ROS) production was enhanced in T2D patients, and mitochondrial ROS was more pronounced in those with poor glycemic control. Levels of gene and protein expression of NLRP3 were decreased in both diabetic groups and mo…
Hypothalamic Apelin/Reactive Oxygen Species Signaling Controls Hepatic Glucose Metabolism in the Onset of Diabetes
2014
Aims: We have previously demonstrated that central apelin is implicated in the control of peripheral glycemia, and its action depends on nutritional (fast versus fed) and physiological (normal versus diabetic) states. An intracerebroventricular (icv) injection of a high dose of apelin, similar to that observed in obese/diabetic mice, increase fasted glycemia, suggesting (i) that apelin contributes to the establishment of a diabetic state, and (ii) the existence of a hypothalamic to liver axis. Using pharmacological, genetic, and nutritional approaches, we aim at unraveling this system of regulation by identifying the hypothalamic molecular actors that trigger the apelin effect on liver gluc…
Emergence of blueschists on Earth linked to secular changes in oceanic crust composition
2015
The oldest blueschists—metamorphic rocks formed during subduction—are of Neoproterozoic age1, and 0.7–0.8 billion years old. Yet, subduction of oceanic crust to mantle depths is thought to have occurred since the Hadean, over 4 billion years ago2. Blueschists typically form under cold geothermal gradients of less than 400 °C GPa−1, so their absence in the ancient rock record is typically attributed to hotter pre-Neoproterozoic mantle prohibiting such low-temperature metamorphism; however, modern analogues of Archaean subduction suggest that blueschist-facies metamorphic conditions are attainable at the slab surface3. Here we show that the absence of blueschists in the ancient geological rec…
Horizontal contraction or horizontal extension? Heterogeneous Late Eocene and early Oligocene general shearing during blueschist and greenschist faci…
1995
Mylonitic structures related to two orogenic events are described from the upper and lower contacts of the Combin zone and the immediately overlying upper Austroalpine Dent Blanche nappe/Mont Mary klippe and the directly underlying lower Austroalpine Etirol-Levaz slice. The first event, Late Eocene in age, commenced during blueschist facies P-T conditions, but pre-dated the peak of subsequent greenschist facies overprint. The second event, Early Oligocene in age, took place during retrograde greenschist facies conditions. Most sense of shear indicators associated with the retrograde mylonites indicate top SE shearing, but subordinate top NW displacing shear sense indicators have also been m…