Search results for "transition"
showing 10 items of 3988 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…
Minimum detection limits and applications of proton and helium induced X-ray emission using transition-edge sensor array
2017
Abstract We have determined minimum detection limits, MDLs, for elements 14 ⩽ Z ⩽ 86 using a transition-edge sensor array, TES array, and as a comparison using an Amptek X-123SDD silicon drift detector, SDD. This was done using a 3 MeV proton beam and a 5.1 MeV helium beam. MDLs were determined for a thin film sample on top of C substrate, and for a bulk sample containing mostly Al. Due to the higher peak-to-background ratio, lower detection limits were obtainable using the TES array for most of the elements. However, for elements 30 ⩽ Z ⩽ 45 the performance of the TES array was not as good as the SDD performance. This is due to the limitations of the TES used at energies >10 keV. The great…
Reduction and catalytic behaviour of heterobimetallic copper–lanthanide oxides
2008
Abstract The reduction of the heterobimetallic copper–lanthanide oxides 2CuO·CeO2 and 3CuO·Ln2CuO4 (Ln = La, Pr, Nd) was studied by H2-TG/DTA and H2-TPR. All systems exhibit two main reduction steps accompanied by mass losses in the temperature range 20–1000 °C. The first step was attributed to CuO reduction, whereas the second step is due either to copper reduction in the Ln2CuO4 phase with the concomitant formation of Ln2O3 or to the surface reduction of CeO2. The products were characterized by XRD, SEM, EDX, and BET techniques and are better described as supported copper type materials. They were active for the mesityl oxide (4-methyl-2-penten-2-one) gas phase hydrogenation.
Interplay of acidity and ionic liquid structure on the outcome of a heterocyclic rearrangement reaction
2021
The study of suitable probe reactions is a powerful tool to investigate the properties of nonconventional solvents such ionic liquids (ILs). In particular, we studied the acid-catalyzed mononuclear rearrangement of heterocycles (MHR) of the Z-phenylhydrazone of 5-amino-3-benzoyl-1,2,4-oxadiazole into the relevant 1,2,3-triazole, in solution of ILs by means of kinetic measurements. We chose as solvents six ILs differing both in the cation and anion, in the presence of five carboxylic and sulfonic acids as catalysts. For a useful comparison, the reaction was also performed in 1,4-dioxane and methanol. In general, the reaction occurs faster in ILs, compared to conventional solvents, according …
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 …
Administration of care to older patients in transition from hospital to home care services: Home nursing leaders' experiences
2013
Published version of an article in the journal: Journal of Multidisciplinary Healthcare. Also available from the Publisher at: http://dx.doi.org/10.2147/JMDH.S51947 Open access Background: Older persons in transition between hospital and home care services are in a particularly vulnerable situation and risk unfortunate consequences caused by organizational inefficiency. The purpose of the study reported here was to elucidate how home nursing leaders experience the administration of care to older people in transition from hospital to their own homes. Methods: A qualitative study design was used. Ten home nursing leaders in two municipalities in southern Norway participated in individual inte…