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551.
Ana Sofia C. Marçal Bruno Celso C. de Freitas Felipe S. Furtado Soares Maria Elizabeth S. Furtado Teresa M. Maciel Arnaldo D. Belchior 《Innovations in Systems and Software Engineering》2008,4(1):17-29
Software development organizations that have been employing capability maturity models, such as SW-CMM or CMMI for improving their processes are now increasingly interested in the possibility of adopting agile development methods. In the context of project management, what can we say about Scrum’s alignment with CMMI? The aim of our paper is to present the mapping between CMMI and the agile method Scrum, showing major gaps between them and identifying how organizations are adopting complementary practices in their projects to make these two approaches more compliant. This is useful for organizations that have a plan-driven process based on the CMMI model and are planning to improve the agility of processes or to help organizations to define a new project management framework based on both CMMI and Scrum practices. 相似文献
552.
Tibor Y. Stigter Marta Varanda Sofia Bento João Pedro Nunes Rui Hugman 《Water Resources Management》2017,31(2):609-628
A combined assessment of the potential impacts from climate change (CC) and socio-economic development (SED) on water resources is presented for the most important aquifer in the south of Portugal. The goal is to understand how CC and SED affect the currently large pressures from water consuming and contaminating activities, predominantly agriculture. Short-term (2020–2050) and long-term (2070–2100) CC scenarios were developed and used to build aquifer recharge and crop water demand scenarios, using different methods to account for uncertainty. SED scenarios were developed using bottom-up and top-down methods, and discussed at workshops with farmers and institutional stakeholders in the water sector. Groundwater use was quantified for each scenario. Together with the recharge scenarios, these were run through a calibrated groundwater flow model, to study their individual and joint impacts on groundwater levels and discharge rates into a coastal estuary. Recharge scenarios show clear negative long-term trends and short-term increase in temporal variability of recharge, though short-term model uncertainties are higher. SED scenario 1 (SED1), predicting intensification and decline of small farms, considered the most likely by all workshop participants, shows a large drop in agricultural area and water demand. SED2, a most desired scenario by farmers, foresees growth and modernization of agriculture, but proves unsustainable in combination with predicted CC without efficient adaptation measures. The results thus reveal that CC in the region will dynamically interact with economic factors, and going one step beyond, CC could be directly integrated as a constraint in the development of SED scenarios. Exercises involving the integration of CC and SED regionally based scenarios, constructed in both bottom-up and top- down fashion and discussed in participatory contexts are still rarely used for adaptation, and specifically adaptation of agriculture to water scarcity. The joint analysis of CC and SED revealed challenging, as it involved the use of different methods across the border between natural and social sciences. In our view this method contributes in an encouraging manner to a more holistic and transdisciplinary water management, by allowing a more plausible identification of what (and if) adaptation measures are needed. 相似文献
553.
Résumé La réduction électrochimique de AlCl3 dans les mélanges NaCl-KCl-LiCl et NaCl-KCl-LiCl-LiF fondus à 450°C, a été étudiée par chronopotentiométrie et chronoamperométrie sur électrode d'argent. Les chronopotentiogrammes et les chronoamperogrammes obtenus, sont interpretés comme un processus simple, regi par la diffusion, entre espèces solubles qui met en jeu l'échange d'un nombre apparentn d'électrons dont la valeur décroit, tout en restant cependant voisine de 2, au fur et a mesure que la densité du courant imposé diminue.Nous avons également étudié le profil de diffusion du dépôt formé à l'intérieur de l'électrode d'argent à l'aide de la microsonde électronique et calculé en utilisant les courbes chronoamperométriquesI = f(t), une valeur approximative du coefficient de diffusion de l'aluminium,
, réduit sur cette même électrode, qui est du même ordre de grandeur dans les deux électrolytes étudiés.
10 × 10–12 cm2s–1 pourn=3.
The electrochemical reduction of AlCl3 in the molten electrolytes NaCl-KCl-LiCl and NaCl-KCl-LiCl-LiF at 450°C was studied by means of chronopotentiometry and chronoamperometry on a silver electrode. We interpreted the obtained chronopotentiometric and chronoamperometric curves by means of a simple, diffusion-controlled reaction between soluble species involving the exchange ofn electrons. The calculated apparent value ofn decreased as the applied current density was reduced, but it remained always approximately equal to 2.We also investigated the diffusion profile of the deposit in the bulk of the silver electrode by means of a microprobe analyser and calculated, using theI=f(t) curves, an approximate value of the diffusion coefficient , of aluminium reduced on this electrode. This value is approximately the same for both electrolytic melts used, i.e. 10×10–12 cm2s–1, assuming thatn=3.相似文献
554.
Ethanol combined with heparin as a locking solution for the prevention of catheter related blood stream infections in hemodialysis patients: A prospective randomized study
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Sofia Sofroniadou Ioanna Revela Alexandros Kouloubinis Ioanna Makriniotou Sinodi Zerbala Despina Smirloglou Petros Kalocheretis Apostolos Drouzas George Samonis Christos Iatrou 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(4):498-506
Introduction: Ethanol lock solution has been mainly administered in paediatric and home parenteral nutrition patients in order to prevent catheter related blood stream infections (CRBSI). Its utility in hemodialysis (HD) patients with non‐tunneled‐uncuffed catheter (NTC) has been poorly explored. Methods: We conducted a prospective randomized study in chronic HD patients requiring a newly inserted NTC‐while awaiting for the maturation of an already established arteriovenous fistula (AVF) or arteriovenous graft (AVG) or tunneled‐cuffed catheter insertion. Patients were randomized in two groups: Group A, where the lock solution was ethanol 70% + unfractionated heparin 2000 U/mL and group B, that received only unfractionated heparin 2000 U/mL. Primary end point was CRBSIs whereas exit site infections, thrombotic and bleeding episodes were the secondary end points. Findings: One hundred three HD patients were enrolled in the study (group A, n = 52; group B, n = 51). The median number of catheter days was 32 for group A (range: 23–39) and 34 (range: 27–40) for group B with no statistically significant difference between the two groups. Group A (ethanol + heparin) demonstrated 4/52 episodes (7.69%) of CRBSI whereas Group B (heparin) 11/51 episodes (21.57%) (P = 0.04). CRBSI rates per 1000 catheter days were 2.53/1000 catheter days for group A and 6.7/1000 catheter days for group B (P = 0.04). Mean cumulative infection‐free catheter survival in the ethanol group did not differ significantly compared to the heparin group (log‐rank test = 2.99, P = 0.08). Thrombotic episodes did not differ between the two groups. Discussion: Locking of NTCs in HD patients with ethanol 70% + unfractionated heparin reduces CRBSI rates without increasing the thrombotic episodes. 相似文献
555.
Albert Gevorkian Sofia M. Morozova Sina Kheiri Nancy Khuu Heyu Chen Edmond Young Ning Yan Eugenia Kumacheva 《Advanced functional materials》2021,31(17):2010743
Polymer hydrogels exhibit actuation properties that result in reversible shape transformations and have promising applications in soft robotics, drug delivery systems, sensors, and microfluidic devices. Actuation occurs due to differential hydrogel swelling and is generally achieved by modulating hydrogel composition. Here a different approach to hydrogel actuation that originates solely from its structural anisotropy is reported. For 3D-printed single-layer hydrogels formed by cellulose nanocrystals (CNCs) and gelatin methacryloyl it is shown that shear-induced orientation of CNCs results in anisotropic mechanical and swelling properties of the hydrogel. Upon swelling in water, planar hydrogels acquire multiple complex 3D shapes that are achieved by i) varying CNC orientation with respect to the shape on the hydrogel sheet and ii) patterning the hydrogel with the regions of shear-mediated and random CNC orientation. This study shows the capability to generate multiple shapes from the same hydrogel actuator based on the degree of its structural anisotropy. In addition, it introduces a biocompatible nanocolloidal ink with shear-thinning and self-healing properties for additive manufacturing of hydrogel actuators. 相似文献
556.
Cybersecurity investments with nonlinear budget constraints and conservation laws: variational equilibrium,marginal expected utilities,and Lagrange multipliers
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Gabriella Colajanni Patrizia Daniele Sofia Giuffrè Anna Nagurney 《International Transactions in Operational Research》2018,25(5):1443-1464
In this paper, we propose a new cybersecurity investment supply chain game theory model, assuming that the demands for the product are known and fixed and, hence, the conservation law of each demand market is fulfilled. The model is a generalized Nash equilibrium model with nonlinear budget constraints for which we define the variational equilibrium, which provides us with a variational inequality formulation. We construct an equivalent formulation, enabling the analysis of the influence of the conservation laws and the importance of the associated Lagrange multipliers. We find that the marginal expected transaction utility of each retailer depends on this Lagrange multiplier and its sign. Finally, numerical examples with reported equilibrium product flows, cybersecurity investment levels, and Lagrange multipliers, along with individual firm vulnerability and network vulnerability, illustrate the obtained results. 相似文献
557.
Raul Martin Victoria de Juan Guadalupe Rodriguez Sofia Martin Soraya Fonseca 《Contact lens & anterior eye》2007,30(1):23-28
PURPOSE: To compare the initial comfort afforded by silicone hydrogel lenses (lotrafilcon A) versus the comfort afforded by conventional hydrogel lenses (etafilcon A) in extended wear (EW). DESIGN: Prospective, double-masked and randomized controlled trial. METHODS: Lotrafilcon A and etafilcon A contact lenses were eye randomly fitted on an EW basis for 7 days and nights in 20 subjects. A forced-choice subject preference questionnaire was made. Subjects were comfort, dryness, red eye and visual quality after night wear and at the end of the day. Subjective scored satisfaction (scale: 1-5) and lens preference were assessed. RESULTS: Lotrafilcon A proved more comfortable after night wear (60%, CI95% 38-82%) and at the end of the day (70%, CI95% 49-90%) than etafilcon A after night wear (10%, CI95% 0-23%, P<0.05) and at the end of the day (20%, CI95% 2-38%, P<0.05). The feeling of dryness was more marked with etafilcon A after night wear (50%, CI95% 27-72%) and at the end of the day (50%, CI95% 27-72%) than it was with lotrafilcon A (15%, CI95% 0%-31%) after night wear (P>0.05) and at the end of the day (25%, CI95% 5%-44%, P<0.05). General satisfaction with the lotrafilcon A lens was 3.65 points (CI95% 3-4.2) and with etafilcon A 2.95 points (CI95% 2.5-3.3, P<0.05). Eighty percent (CI95% 62%-98%) of subjects preferred lotrafilcon A (P<0.05) for EW. CONCLUSIONS: In EW, lotrafilcon A contact lenses were more comfortable and led to less dryness after night wear and at the end of the day than etafilcon A contact lenses. 相似文献
558.
Maria Fernanda Nascimento Neves Carvalho Jan Cermák Anabela Catarino Fernandes Ana Sofia Ferreira Adelino Moura Galvão Inês Matos Maria Mercês Marques 《Polymer International》2007,56(5):613-620
The properties of [NiX(PR2CH2C(But)?NN?C(But)CH2PR2)]+ complexes (where X = Br, and R = cyclohexyl (Cy), isopropyl (Pri), tert‐butyl (But), phenyl (Ph); X = Cl or I, and R = cyclohexyl) as catalysts for the polymerisation of ethylene were evaluated with or without the co‐catalysts methylaluminoxane (MAO), diethylaluminium chloride, trimethylaluminium or tri(isobutyl)aluminium. Their efficiency depends on the characteristics of the halogen (X) and the R group of the diphosphine azine ligand. Bromide (X) strongly enhances the catalytic properties of the complexes within the R order Cy > Pri > Ph > But. Temperature, co‐catalyst ratio (Al/Ni) and complex concentration also influence the catalytic activity. The best results were obtained with [NiBr{PCy2CH2C(But)?NN?C(But)CH2PCy2}]Br activated by MAO (A = 25.8 kg (mol Ni)?1 bar?1 h?1). The polymers were characterised using NMR and differential scanning calorimetry as branched polyethylenes, the number of branches increasing with the temperature of polymerisation. The molecular weights of the polymers were estimated using NMR. A proposal for the catalyst active precursor is made on the basis of experimental data and molecular orbital calculations. Copyright © 2007 Society of Chemical Industry 相似文献
559.
Gemma Di Pompo Margherita Cortini Roberto Palomba Valentina Di Francesco Elena Bellotti Paolo Decuzzi Nicola Baldini Sofia Avnet 《International journal of molecular sciences》2021,22(11)
In the tumor microenvironment, mesenchymal stromal cells (MSCs) are key modulators of cancer cell behavior in response to several stimuli. Intratumoral acidosis is a metabolic trait of fast-growing tumors that can induce a pro-tumorigenic phenotype in MSCs through the activation of the NF-κB-mediated inflammatory pathway, driving tumor clonogenicity, invasion, and chemoresistance. Recent studies have indicated that curcumin, a natural ingredient extracted from Curcuma longa, acts as an NF-κB inhibitor with anti-inflammatory properties. In this work, highly proliferating osteosarcoma cells were used to study the ability of curcumin to reduce the supportive effect of MSCs when stimulated by acidosis. Due to the poor solubility of curcumin in biological fluids, we used spherical polymeric nanoparticles as carriers (SPN-curc) to optimize its uptake by MSCs. We showed that SPN-curc inhibited the release of inflammatory cytokines (IL6 and IL8) by acidity-stimulated MSCs at a higher extent than by free curcumin. SPN-curc treatment was also successful in blocking tumor stemness, migration, and invasion that were driven by the secretome of acid-stressed MSCs. Overall, these data encourage the use of lipid–polymeric nanoparticles encapsulating NF-κB inhibitors such as curcumin to treat cancers whose progression is stimulated by an activated mesenchymal stroma. 相似文献
560.