Export 9213 results:
Sort by: Author Title Type [ Year  (Desc)]
2011
Pinheiro, Carla, Carla Antonio, Maria Fernanda Ortuno, Petre I. Dobrev, Wolfram Hartung, Jane Thomas-Oates, Candido Pinto Ricardo, Radomira Vankova, Manuela M. Chaves, and Julie C. Wilson. "Initial water deficit effects on Lupinus albus photosynthetic performance, carbon metabolism, and hormonal balance: metabolic reorganization prior to early stress responses." Journal of Experimental Botany. 62 (2011): 4965-4974. AbstractWebsite

The early (2-4 d) effects of slowly imposed soil water deficit on Lupinus albus photosynthetic performance, carbon metabolism, and hormonal balance in different organs (leaf blade, stem stele, stem cortex, and root) were evaluated on 23-d-old plants (growth chamber assay). Our work shows that several metabolic adjustments occurred prior to alteration of the plant water status, implying that water deficit is perceived before the change in plant water status. The slow, progressive decline in soil water content started to be visible 3 d after withholding water (3 DAW). The earliest plant changes were associated with organ-specific metabolic responses (particularly in the leaves) and with leaf conductance and only later with plant water status and photosynthetic rate (4 DAW) or photosynthetic capacity (according to the Farquhar model; 6 DAW). Principal component analysis (PCA) of the physiological parameters, the carbohydrate and the hormone levels and their relative values, as well as leaf water-soluble metabolites full scan data (LC-MS/MS), showed separation of the different sampling dates. At 6 DAW classically described stress responses are observed, with plant water status, ABA level, and root hormonal balance contributing to the separation of these samples. Discrimination of earlier stress stages (3 and 4 DAW) is only achieved when the relative levels of indole-3-acetic acid (IAA), cytokinins (Cks), and carbon metabolism (glucose, sucrose, raffinose, and starch levels) are taken into account. Our working hypothesis is that, in addition to single responses (e.g. ABA increase), the combined alterations in hormone and carbohydrate levels play an important role in the stress response mechanism. Response to more advanced stress appears to be associated with a combination of cumulative changes, occurring in several plant organs. The carbohydrate and hormonal balance in the leaf (IAA to bioactive-Cks; soluble sugars to IAA and starch to IAA; relative abundances of the different soluble sugars) flag the initial responses to the slight decrease in soil water availability (10-15% decrease). Further alterations in sucrose to ABA and in raffinose to ABA relative values (in all organs) indicate that soil water availability continues to decrease. Such alterations when associated with changes in the root hormone balance indicate that the stress response is initiated. It is concluded that metabolic balance (e.g. IAA/bioactive Cks, carbohydrates/IAA, sucrose/ABA, raffinose/ABA, ABA/IAA) is relevant in triggering adjustment mechanisms.

Pinheiro, Carla, Carla Antonio, Maria Fernanda Ortuno, Petre I. Dobrev, Wolfram Hartung, Jane Thomas-Oates, Candido Pinto Ricardo, Radomira Vankova, Manuela M. Chaves, and Julie C. Wilson. "Initial water deficit effects on Lupinus albus photosynthetic performance, carbon metabolism, and hormonal balance: metabolic reorganization prior to early stress responses." Journal of Experimental Botany. 62 (2011): 4965-4974. AbstractWebsite
n/a
Valtchev, S., R. Medeiros, S. Valtchev, and B. Klaassens. "An instantaneous regulation for the wired and wireless super-resonant converters." INTELEC, International Telecommunications Energy Conference (Proceedings) (2011). Abstract
n/a
Carvalho, H., and V. Cruz-Machado. "Integrating lean, agile, resilience and green paradigms in supply chain management." Supply Chain Management. Pengzhong Li ed. {InTech}, 2011. 27-48. Abstract
n/a
Cardoso, Alberto, M. & S. Vieira, and P. Gil. "Integration of a Remote and Virtual Control Lab in an Intelligent Tutoring System." REV 2011. n/a 2011. Abstract
n/a
Mollegaard, Karen Mai, Karen Duus, Sofie Dietz Traeholt, Morten Thaysen-Andersen, Yan Liu, Angelina S. Palma, Ten Feizi, Paul R. Hansen, Peter Hojrup, and Gunnar Houen. "The interactions of calreticulin with immunoglobulin G and immunoglobulin Y." Biochimica Et Biophysica Acta-Proteins and Proteomics. 1814 (2011): 889-899. Abstract
n/a
Santos, J. P., A. M. Costa, M. C. Martins, P. Indelicato, and F. Parente. "K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions." Journal of Physics: Conference Series. Accepted (2011).
Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by X-ray Fluorescence and Electrothermal Atomic Absorption Spectrometry." X-Ray Spectrometry. In press (2011). Abstract
n/a
Antunes, R., F. Coito, and H. Duarte-Ramos. "A Linear Approach towards Modeling Human Behavior." Technological Innovation for Sustainability (2011): 305-314. Abstract
n/a
Sena, C., M. H. Godinho, Cristiano Luis Pinto de Oliveira, and AM Figueiredo Neto. "Liquid crystalline cellulosic elastomers: free standing anisotropic films under stretching." Cellulose. 18.5 (2011): 1151. Abstract
n/a
Timoteo, C. G., AS Pereira, C. E. Martins, S. G. Naik, A. G. Duarte, JJG Moura, P. Tavares, BH HUYNH, and I. Moura. "Low-Spin Heme b(3) in the Catalytic Center of Nitric Oxide Reductase from Pseudomonas nautica." Biochemistry. 50 (2011): 4251-4262. AbstractWebsite

Respiratory nitric oxide reductase (NOR) was purified from membrane extract of Pseudomonas (Ps.) nautica cells to homogeneity as judged by polyacrylamide gel electrophoresis. The purified protein is a heterodimer with subunits of molecular masses of 54 and 18 kDa. The gene encoding both subunits was cloned and sequenced. The amino acid sequence shows strong homology with enzymes of the cNOR class. Iron/heme determinations show that one heme c is present in the small subunit (NORC) and that approximately two heme b and one non-heme iron are associated with the large subunit (NORB), in agreement with the available data for enzymes of the cNOR class. Mossbauer characterization of the as-purified, ascorbate-reduced, and dithionite-reduced enzyme confirms the presence of three heme groups (the catalytic heme b(3) and the electron transfer heme b and heme c) and one redox-active non-heme Fe (Fe-B). Consistent with results obtained for other cNORs, heme c and heme b in Ps. nautica cNOR were found to be low-spin while FeB was found to be high-spin. Unexpectedly, as opposed to the presumed high-spin state for heme b(3), the Mossbauer data demonstrate unambiguously that heme b(3) is, in fact, low-spin in both ferric and ferrous states, suggesting that heme b(3) is six-coordinated regardless of its oxidation state. EPR spectroscopic measurements of the as-purified enzyme show resonances at the g similar to 6 and g similar to 2-3 regions very similar to those reported previously for other cNORs. The signals at g = 3.60, 2.99, 2.26, and 1.43 are attributed to the two charge-transfer low-spin ferric heme c and heme b. Previously, resonances at the g similar to 6 region were assigned to a small quantity of uncoupled high-spin Fe-III heme b(3). This assignment is now questionable because heme b(3) is low-spin. On the basis of our spectroscopic data, we argue that the g = 6.34 signal is likely arising from a spin spin coupled binuclear center comprising the low-spin Fe-III heme b(3) and the high-spin Fe-B(III). Activity assays performed under various reducing conditions indicate that heme b(3) has to be reduced for the enzyme to be active. But, from an energetic point of view, the formation of a ferrous heme-NO as an initial reaction intermediate for NO reduction is disfavored because heme [FeNO](7) is a stable product. We suspect that the presence of a sixth ligand in the Fe-II-heme b(3) may weaken its affinity for NO and thus promotes, in the first catalytic step, binding of NO at the Fe-B(II) site. The function of heme b(3) would then be to orient the Fe-B-bound NO molecules for the formation of the N-N bond and to provide reducing equivalents for NO reduction.

Duarte, Susana, and Cruz} {V. Machado. "Manufacturing paradigms in supply chain management." International Journal of Management Science and Engineering Management. 6 (2011): 328-342. Abstract

This paper intends to determine whether the lean, agile, resilient and green paradigms are applied and combined in the actual environment of supply-chain management. A structured literature review on the state of the art was carried out, thus providing a comprehensive understanding on supply-chain management. A classification scheme of supply-chain paradigms was developed where five databases were used to find how these paradigms were being integrated. The research developed provided the confirmation that papers combining more than two paradigms were rare. To date, academicians have not studied the merging of these paradigms in supply-chain management at significant depth.

Xavier, J., J. Morais, N. Dourado, and M. F. S. F. de Moura. "Measurement of mode I and mode II fracture properties of wood-bonded joints." Journal of Adhesion Science and Technology. 25 (2011): 2881-2895. Abstract
n/a
Valtchev, Stanimir. "Medium concentration system HSUN: demonstration results and application of diverse silicon cells." 26th European Photovoltaic Solar Energy Conference and Exhibition (PVSEC). 2011. Abstract
n/a
Alves, M., P. Chicau, H. Matias, J. Passarinho, C. Pinheiro, and C. P. Ricardo. "Metabolic analysis revealed altered amino acid profiles in Lupinus albus organs as a result of boron deficiency." Physiologia Plantarum. 142 (2011): 224-232. AbstractWebsite

We analysed the changes in the metabolites of Lupinus albus organs (leaf-blades, petioles, apexes, hypocotyls and roots) as a consequence of B deficiency. The deficiency did not affect malate concentration and induced only minor changes in the sugar content, suggesting that the carbohydrate metabolism is little affected by the deficiency. Contrarily, marked changes in the content of free amino acids were observed, with some specific variations associated with the different organs. These changes indicate that various aspects of metabolism implicated in the amino acid accumulation were affected by B deficiency. Most of the detected changes appear to have implications with some stress responses or signalling processes. Asparagine and proline that increase in many stresses also accumulated in petioles, apexes and hypocotyls. Accumulation of gamma-aminobutyric acid shunt amino acids, indicative of production of reactive oxygen species, occurs in the same three organs and also the roots. The increase in the branched-chain amino acids, observed in all organs, suggests the involvement of B with the cytoskeleton, whereas glycine decrease in leaf-blades and active growing organs (apexes and roots) could be associated with the proposed role of this amino acids in plant signalling in processes that might be associated with the decreased growth rates observed in B deficiency. Despite the admitted importance of free amino acids in plant metabolism, the available information on this matter is scarce. So our results bring new information concerning the effects of B deficiency in the metabolism of the several L. albus organs.

Alves, M., P. Chicau, H. Matias, J. Passarinho, C. Pinheiro, and C. P. Ricardo. "Metabolic analysis revealed altered amino acid profiles in Lupinus albus organs as a result of boron deficiency." Physiologia Plantarum. 142 (2011): 224-232. AbstractWebsite
n/a
Águas, H., I. Bernacka-Wojcik, T. Busani, E. Fortunato, R. Martins, P. Lopes, P. Simões, M. Ferreira, and L. Hilliou. "Microplat project: development status." III Annual Meeting of the I3N–Institute of Nanostructures, Nanomodelling and Nanofabrication, 2011. 2011. 9. Abstract
n/a
Araújo, João, Michael Kinyon, and Janusz Konieczny. "Minimal paths in the commuting graphs of semigroups." European J. Combin.. 32 (2011): 178-197. AbstractWebsite
n/a
Silva, Tiago A. N., and M. A. R. Loja Minimization of Thermal Residual Stresses on Functionally Graded Sandwich Structures Using Differential Evolution. Eds. Marques V. A Madureira C. Reis. 2nd International Symposium on Computational Intelligence for Engineering Systems (ISCIES 2011)., 2011. Abstract
n/a
Gil, P., A. Paulo, L. Palma, A. Santos, and Alberto Cardoso. "Model Based Predictive Control over Wireless Sensor and Actuator Networks." The 37th Annual Conference of the IEEE Industrial Electronics Society (IECON 2011). n/a 2011. Abstract
n/a
Gomes, Maria Isabel, Ana Paula Barbosa-povoa, and Augusto Q. Novais. "Modelling a recovery network for WEEE: A case study in Portugal." Waste Management. 31 (2011): 1645-1660. AbstractWebsite

The European Union directive for electric and electronic waste, published in 2003, enforced all European countries to meet some targets concerning the recycling and recovery of these products. This directive was transposed to the Portuguese legislation in 2004. Following this, a group of EEE producers set up an organization (Amb3e) whose mission was to design and manage a nationwide recovery network for WEEE, which will be the subject matter of this work. A generic MILP model is proposed to represent this network, which is applied to its design and planning, where the best locations for collection and sorting centres are chosen simultaneously with the definition of a tactical network planning. Several analyses are performed to provide further insights regarding the selection of these alternative locations. The results gave support to the company strategic expansion plans for a high number of centres to be opened and to their location near the major WEEE sources.

Guerra, M., F. Parente, P. Indelicato, and J. P. Santos. "Modified binary encounter Bethe model for electron-impact ionization." International Journal of Mass Spectrometry. Accepted (2011). Abstract

Theoretical expressions for ionization cross sections by electron impact based on the binary encounter Bethe (BEB) model, valid from ionization threshold up to relativistic energies, are proposed.The new modified BEB (MBEB) and its relativistic counterpart (MRBEB) expressions are simpler than the BEB (nonrelativistic and relativistic) expressions because they require only one atomic parameter, namely the binding energy of the electrons to be ionized, and use only one scaling term for the ionization of all sub-shells.The new models are used to calculate the K-, L- and M-shell ionization cross sections by electron impact for several atoms with Z from 6 to 83.Comparisons with all, to the best of our knowledge, available experimental data show that this model is as good or better than other models, with less complexity.

Garcia-Alvarez, Begona, Roberto Melero, Fernando M. V. Dias, Jose A. M. Prates, Carlos M. G. A. Fontes, Steven P. Smith, Maria Joao Romao, Ana Luisa Carvalho, and Oscar Llorca. "Molecular Architecture and Structural Transitions of a Clostridium thermocellum Mini-Cellulosome." Journal of Molecular Biology. 407 (2011): 571-580. Abstract
n/a
Nunes, G. N. N. V., Alberto Cardoso, A. Santos, and P. Gil. "Multi-agent Topologies over WSANs in the Context of Fault Tolerant Supervision." DoCEIS 2011 - 2nd Edition of the Doctoral Conference on Computing, Electrical and Industrial Systems. n/a 2011. Abstract
n/a