Search results for " transition"
showing 10 items of 2751 documents
Timing the Mesolithic-Neolithic Transition in the Iberian Peninsula: The Radiocarbon Dataset
2019
In this paper, we describe the radiocarbon dataset compiled in the context of the project HAR2015-68962 EVOLPAST: Dinamicas evolutivas y patrones de variabilidad cultural de los ultimos cazadores-recolectores y el primer Neolitico en el este peninsular (7000–4500 cal. BC) funded by the Spanish government. The dataset offers the most complete and public radiocarbon dataset focus on the Neolithic Transition in the Iberian Peninsula. Funding statement: The data collection was funded by the Spanish Ministry of Economy, Industry and Competitiveness grant HAR2015-68962-P to Oreto Garcia Puchol & Joan Bernabeu. SPG is supported by Spanish Ministry of Economy, Industry and Competitiveness, Postdoct…
Kompleksy metali przejściowych z zasadami Lewisa jako prekursory katalizatorów polimeryzacji olefin. Cz. I. Postęp w komputerowym modelowaniu procesu…
2001
A review with 35 references covering molecular modeling in coordination polymerization over homogeneous and heterogeneous Ziegler-Natta catalysts. The study includes supports, cocatalysts, Lewis bases and solvents. Recent progress in elucidating the mechanisrn of elementary polymerization steps is presented against the background of rapidly deveIoping computational methods and available computational power. Theoretical studies on polymerization mcchanisms and structure of active centers are described (egns. 1-4). Authors own calculations are used to compare [MtC14(THF)2] complex-based (Mt = Ti, Hf or Zr) heterogeneous catalysts. The geometrical characteristics of precursors is presented (Ta…
Appropriate management of growth hormone deficiency during the age of transition: an Italian Delphi consensus statement
2022
Growth hormone deficiency (GHD) describes the impairment of growth hormone (GH) secretion by the pituitary somatotroph cells. GHD may be congenital, with causes, including genetic alterations and structural brain malformations, or acquired, including midline tumours, cranial irradiation, traumatic brain injury, central nervous system infections and inflammatory conditions. GHD in children is characterised by short stature, delayed bone maturation and abnormalities in substrate metabolism, body composition, physical and psychosocial functioning, all of which improve with recombinant human GH (rhGH) therapy. The diagnosis of GHD is based on clinical signs and symptoms, biochemistry and imagin…
Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups☆
2013
Background Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. Objectives To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. Material and methods Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glut…
Participation for just governance of food-system transition
2022
Sustainability transitions governance needs to be inclusive and participatory and the question of justice is crucial for making effective and acceptable changes possible. But how do we ensure adequate participation in governance processes and enable reconciliation between competing goals in relation to sustainability transitions? Transition management highlights the need for participatory and reflexive governance processes to enable sustainability transitions. However, due to participant selection and limitations in chosen approaches, deliberative and participatory forums may have difficulties ensuring justice and legitimacy. A systemic and practice-oriented perspective on deliberation poin…
Responsibilities for just transition to low-carbon societies : a role-based framework
2022
Low-carbon transitions in industrialised societies will have significant social, economic and environmental impacts, raising concerns of justice. Calls for urgent transitions evoke a question about the roles of different actors in advancing transitions and ensuring they are just. While the responsibilities for emission mitigation have been long discussed, responsibilities for making a just transition have not. The question about responsibilities is particularly pressing because of the diverse constellation of actors involved in climate action, including diverse forms of non-state actors from city-level and business alliances to grassroots activists. We examine the responsibilities of state …
Nitrated Fatty Acids Modulate the Physical Properties of Model Membranes and the Structure of Transmembrane Proteins
2017
Nitrated fatty acids (NO2 -FAs) act as anti-inflammatory signal mediators, albeit the molecular mechanisms behind NO2 -FAs' influence on diverse metabolic and signaling pathways in inflamed tissues are essentially elusive. Here, we combine fluorescence measurements with surface-specific sum frequency generation vibrational spectroscopy and coarse-grained computer simulations to demonstrate that NO2 -FAs alter lipid organization by accumulation at the membrane-water interface. As the function of membrane proteins strongly depends on both, protein structure as well as membrane properties, we consecutively follow the structural dynamics of an integral membrane protein in presence of NO2 -FAs. …
A neutron diffraction study of the glass transition in (KBr)0.47(KCN)0.53
1985
Abstract The molecular crystal (KBr) 0.47 (KCN) 0.53 has been investigated by elastic neutron diffraction at the transition from the paraelastic to the orientational glass state. The freezing temperature is characterized by the onset of a momentum transfer dependent broadening of the diffraction lines indicating the transition from a crystalline to an amorphous state.
Determination of the Boron/Lead Ratio in Ceramic Materials Based on Electrochemical Quartz Crystal Microbalance
2004
A method for quantitatively determining the relationship boron/lead in ceramic materials is presented. It is based on the attachment of microsamples of ceramic frits to an electrochemical quartz crystal microbalance (EQCM). After a reductive deposition step in the � 0.25 to � 0.85 V (vs. AgCl/Ag) potential range, well-defined stripping peaks are recorded in 0.10 M NaCl plus 0.10 M mannitol. The deposition of boron and lead from suspensions of solid materials, and its subsequent oxidative dissolution can be monitorized at the EQCM. The quotient between the maximum mass gain and the corresponding charge passed enables for a direct quantitation of the boron/lead molar ratio in ceramic material…
Hydration dependence of myoglobin dynamics studied with elastic neutron scattering, differential scanning calorimetry and broadband dielectric spectr…
2014
In this work we present a thorough investigation of the hydration dependence of myoglobin dynamics. The study is performed on D2O-hydrated protein powders in the hydration range 0<h<0.5 (h≡gr[D2O]/gr[protein]) and in the temperature range 20-300K. The protein equilibrium fluctuations are investigated with Elastic Neutron Scattering using the spectrometer IN13 at ILL (Grenoble), while the relaxations of the protein + hydration water system are investigated with Broadband Dielectric Spectroscopy; finally, Differential Scanning Calorimetry is used to obtain a thermodynamic description of the system. The effect of increasing hydration is to speed up the relaxations of the myoglobin + hydration …