Showing papers by "Polytechnic University of Valencia published in 2009"
TL;DR: PYR/PYLs are ABA receptors functioning at the apex of a negative regulatory pathway that controls ABA signaling by inhibiting PP2Cs, illustrating the power of the chemical genetic approach for sidestepping genetic redundancy.
Abstract: Type 2C protein phosphatases (PP2Cs) are vitally involved in abscisic acid (ABA) signaling. Here, we show that a synthetic growth inhibitor called pyrabactin functions as a selective ABA agonist. Pyrabactin acts through PYRABACTIN RESISTANCE 1 (PYR1), the founding member of a family of START proteins called PYR/PYLs, which are necessary for both pyrabactin and ABA signaling in vivo. We show that ABA binds to PYR1, which in turn binds to and inhibits PP2Cs. We conclude that PYR/PYLs are ABA receptors functioning at the apex of a negative regulatory pathway that controls ABA signaling by inhibiting PP2Cs. Our results illustrate the power of the chemical genetic approach for sidestepping genetic redundancy.
2,336 citations
TL;DR: Magnusson expansion as discussed by the authors provides a power series expansion for the corresponding exponent and is sometimes referred to as Time-Dependent Exponential Perturbation Theory (TEPT).
1,013 citations
17 Jun 2009
TL;DR: This article explored the influence of different mechanisms in lowering barriers related to the orientation of universities and to the transactions involved in working with university partners, and explored the effects of collaboration experience, breadth of interaction, and inter-organizational trust on lowering different types of barriers.
Abstract: Although the literature on university–industry links has begun to uncover the reasons for, and types of, collaboration between universities and businesses, it offers relatively little explanation of ways to reduce the barriers in these collaborations. This paper seeks to unpack the nature of the obstacles to collaborations between universities and industry, exploring influence of different mechanisms in lowering barriers related to the orientation of universities and to the transactions involved in working with university partners. Drawing on a large-scale survey and public records, this paper explores the effects of collaboration experience, breadth of interaction, and inter-organizational trust on lowering different types of barriers. The analysis shows that prior experience of collaborative research lowers orientation-related barriers and that greater levels of trust reduce both types of barriers studied. It also indicates that breadth of interaction diminishes the orientation-related, but increases transaction-related barriers. The paper explores the implications of these findings for policies aimed at facilitating university–industry collaboration.
858 citations
TL;DR: This work analyzes experimentally the behaviour of 18 different performance metrics in several scenarios, identifying clusters and relationships between measures and makes a comprehensive analysis of the relationships between metrics, and a taxonomy and arrangement of them according to the previous traits.
637 citations
TL;DR: This paper identifies the key steps in model design and diverse problems, formulations, levels of integration, spatial and temporal scales, and solution techniques addressed and used by over 80 hydro-economic modeling efforts dating back 45 years from 23 countries.
617 citations
TL;DR: Applications described include process monitoring, shelf-life investigation, freshness evaluation, authenticity assessment, as well as other general aspects of the utilization of electronic noses in food control.
527 citations
TL;DR: The overall efficiency of (Zn/Cr)LDH for visible light oxygen generation was found to be 1.6 times higher than that of WO(3) under the same conditions.
Abstract: Oxygen generation through photocatalytic water splitting under visible light irradiation is a challenging process. In this work we have synthesized a series of Zn/Ti, Zn/Ce, and Zn/Cr layered double hydroxides (LDH) at different Zn/metal atomic ratio (from 4:2 to 4:0.25) and tested them for the visible light photocatalytic oxygen generation. The most active material was found to be (Zn/Cr)LDH with an atomic ratio of 4:2 that exhibits two absorption bands in the visible region at λmax of 410 and 570 nm. It was found that the efficiency of these chromium layered double oxides for oxygen generation increases asymptotically with the Cr content. Using iron oxalate as chemical actinometer we have determined that the apparent quantum yields for oxygen generation (Φapparent = 4 × mol oxygen/mol incident photons) are of 60.9% and 12.2% at 410 and 570 nm, respectively. These quantum yields are among the highest values ever determined with visible light for solid materials in the absence of light harvesting dye. The...
484 citations
TL;DR: The crystal structure of Arabidopsis thaliana PYR1 is presented, which consists of a dimer in which one of the subunits is bound to ABA, indicating that conformational changes in these loops have a critical role in the stabilization of the hormone–receptor complex.
Abstract: The plant hormone abscisic acid (ABA) has a central role in coordinating the adaptive response in situations of decreased water availability as well as the regulation of plant growth and development. Recently, a 14-member family of intracellular ABA receptors, named PYR/PYL/RCAR, has been identified. These proteins inhibit in an ABA-dependent manner the activity of a family of key negative regulators of the ABA signalling pathway: the group-A protein phosphatases type 2C (PP2Cs). Here we present the crystal structure of Arabidopsis thaliana PYR1, which consists of a dimer in which one of the subunits is bound to ABA. In the ligand-bound subunit, the loops surrounding the entry to the binding cavity fold over the ABA molecule, enclosing it inside, whereas in the empty subunit they form a channel leaving an open access to the cavity, indicating that conformational changes in these loops have a critical role in the stabilization of the hormone-receptor complex. By providing structural details on the ABA-binding pocket, this work paves the way for the development of new small molecules able to activate the plant stress response.
483 citations
TL;DR: In situ magnetic measurements following guest vapor injection show that most guest molecules transform 1 from the low-spin state to the high-spin (HS) state, whereas CS(2) uniquely causes the reverse HS-to-LS transition.
Abstract: The ins and outs of spin: Using the microporous coordination polymer {Fe(pz)[Pt(CN)(4)]} (1, pz=pyrazine), incorporating spin-crossover subunits, two-directional magnetic chemo-switching is achieved at room temperature. In situ magnetic measurements following guest vapor injection show that most guest molecules transform 1 from the low-spin (LS) state to the high-spin (HS) state, whereas CS(2) uniquely causes the reverse HS-to-LS transition.
446 citations
TL;DR: Substrate degradation is strongly diminished and the catalyst life increased by performing the reaction in two temperature steps, and the absence of metal leaching is verified.
Abstract: 5-hydroxymethyl-2-furfural is selectively converted into 2,5-furandicarboxylic acid (99 mol % yield) in water, under mild conditions (65-130 degrees C, 10 bar air) with gold nanoparticles supported on nanoparticulate ceria (Au-CeO(2)) and on titania (Au-TiO(2)); the former being more active and selective. A reaction mechanism is established and the rate-limiting step of the reaction is the alcohol oxidation of 5-hydroxymethyl-2-furancarboxylic acid into 2,5-furandicarboxylic acid. The effects of pressure, temperature, substrate-to-catalyst ratio, and amount of base are studied to find the most suitable reaction conditions. The absence of metal leaching is verified by chemical analysis of the reaction solution and by confirming that the reaction does not occur after catalyst removal by filtration in hot water. Substrate degradation is strongly diminished and the catalyst life increased by performing the reaction in two temperature steps.
442 citations
TL;DR: In this article, a state of the art of microporous adsorbents in the frame of NG treating is given, including reference and advanced zeolites, carbon based materials and Metal-Organic Frameworks (MOFs).
TL;DR: A new nanoscopic molecular movable gate-like functional hybrid system consisting of nanoscopic MCM-41-based material functionalized onto pore outlets with a saccharide derivative capable of interacting with boronic acid functionalized gold nanoparticles (AuNPs) acting as nanoscopic caps.
Abstract: This paper proposes a new nanoscopic molecular movable gate-like functional hybrid system consisting of nanoscopic MCM-41-based material functionalized onto pore outlets with a saccharide derivative capable of interacting with boronic acid functionalized gold nanoparticles (AuNPs) acting as nanoscopic caps. The gating mechanism involves the reversible reaction between polyalcohols and boronic acids to form boronate esters. Functionalized AuNPs thus act as a suitable nanoscopic cap via the reversible formation of the corresponding boroester bonds with the saccharide derivative anchored on the external surface of the mesoporous silica-based solid. The developed platform operates in aqueous solution and can be triggered by two simple external stimuli such as pH changes or light. The hydrolysis of the boroester bond takes place at pH 3, which results in rapid delivery of the safranine cargo from the pore voids into the aqueous solution. However, at pH 5 the pores are capped with nanoparticles and the delivery is strongly inhibited. The kinetics of the delivery was studied at pH = 3, assuming a simple diffusion process and that the kinetics of guest release from the pore voids of the hybrid material can be explained by the Higuchi model. It is possible to deliver the cargo in small portions by carrying out on-off aperture cycles via changing the pH from 3 to 5. AuNPs also open the possibility of employing light as a suitable stimulus for release procedures using the AuNPs' capacity for raising their temperature locally by absorption of laser light. The plasmonic heating using a Nd:YAG laser at 1064 nm results in the cleavage of the boronic ester linkage that anchors the nanoparticles to the surface of the mesoporous silica-based material, allowing the release of the entrapped guests. Further studies also demonstrated that it is possible to fine-tune the amount of cargo delivered by simply controlling the laser irradiation opening the possibility to designing laser-induced pulsatile release supports.
TL;DR: In this article, the authors present empirical evidence on the effects of external knowledge-sourcing strategies on the development of both product and process innovations, and assesses the degree to which such effects are influenced by the firm's internal technological capacities.
Abstract: This article presents empirical evidence on the effects of external knowledge-sourcing strategies on the development of both product and process innovations, and assesses the degree to which such effects are influenced by the firm's internal technological capacities. In our analysis, we consider two strategies for acquiring external knowledge (buying and cooperating) and two types of external sources (industrial agents and scientific agents). The analysis is based on a sample of 1329 manufacturing firms active in innovation activities taken from the Spanish Survey of Technological Innovation 2004. We find that the effects of the knowledge-sourcing strategies differ significantly across innovation types (product or process innovation). In addition, our results indicate that although internal R&D activities are associated with a greater use of external scientific knowledge sources (through cooperation), they do not seem to promote their exploitation for innovation development, that is, to say, they do not have synergistic effects. Copyright 2009 The Author 2009. Published by Oxford University Press on behalf of Associazione ICC. All rights reserved., Oxford University Press.
TL;DR: In this paper, the main aim of this work was to determine creep and shrinkage variations experienced in recycled concrete, made by replacing the main fraction of the natural aggregate with a recycled aggregate coming from waste concrete and comparing it to a control concrete.
TL;DR: An implementation of the extended finite element method for fracture problems within the finite element software ABAQUSTM is introduced and several numerical examples in fracture mechanics are presented to demonstrate the benefits of the proposed implementation.
TL;DR: The excellent balance between absorption, energy transfer, and emission rate of the Eu ITQMOF-3-Eu allowed the fabrication of a miniaturized pH sensor prototype that functions in the biologically interesting range (5–7.5) and a linear photoluminescence response, which allows the self-calibration of the emitting signal within this pH range, was achieved.
Abstract: The field of lanthanide-based metal–organic frameworks (LnMOFs) with twoor three-dimensional structures is rapidly growing because of the discovery of new crystalline structures that exhibit interesting properties and have potential applications in catalysis, sensors, contrast agents, non-linear optics, 22] displays, and electroluminescent devices. For photoluminescence applications, it is necessary to prepare lanthanide-containing materials with high quantum efficiencies, in order to achieve the required miniaturization and reduce energy losses from undesirable quenching processes. Moreover, it is highly desirable to combine the properties of ligands and antennae in one organic moiety. A well-known powerful sensitizing ligand for Eu ions in solution is 1,10-phenanthroline-2,9-dicarboxylic acid (H2PhenDCA), in which both carboxylic and phenanthroline moieties may coordinate to the metal center. 27] The proximity between the coordinative parts means that this chelating agent has the tendency to form zero-dimensional (molecular) complexes that are useful in some solution-based analytical applications, but cannot be applied as solid sensors or light-emitting materials. Thus, it is of interest to obtain the twoor three-dimensional insoluble counterparts of these zero-dimensional water-soluble complexes. To achieve this goal, we have used hydrothermal synthesis, which is a powerful technique for the preparation of metastable compounds that may not be accessible by using conventional methods. 29] Hydrothermal synthesis also allows the use of chelating agents that are sparingly soluble in water at temperatures below 373 K, thus enhancing the lanthanidecoordinating ability of the ligand. Herein, we report the synthesis, structure, and sensing properties of a new Eu metal–organic framework ITQMOF-3-Eu (ITQMOF = Instituto de Tecnologia Quimica Metal Organic Framework) that contains the ligand 1,10-phenanthroline-2,9-dicarboxylic acid. The excellent balance between absorption, energy transfer, and emission rate of the Eu ITQMOF-3 (ITQMOF-3-Eu) allowed the fabrication of a miniaturized pH sensor prototype that functions in the biologically interesting range (5–7.5). By combining this material and an optical fiber, a linear photoluminescence response, which also allows the self-calibration of the emitting signal within this pH range, was achieved. The ITQMOF-3Eu material was obtained by reacting the H2PhenDCA ligand and the Eu salt or oxide under hydrothermal conditions (see the Supporting Information). The crystal has a strong red luminescence under ultraviolet light (see Figure 1 a). Chemical and elemental analyses showed that the formula of the material is [Eu3(C14H6N2O4)4(OH)(H2O)4]·2 H2O.
TL;DR: The design, research and development of a wireless multisensor network which mixes sensors with IP cameras in a wireless network in order to detect and verify fire in rural and forest areas of Spain and the test performance given by a test bench formed by four wireless IP cameras is shown and the energy consumed when they are transmitting.
Abstract: Forest and rural fires are one of the main causes of environmental degradation in Mediterranean countries. Existing fire detection systems only focus on detection, but not on the verification of the fire. However, almost all of them are just simulations, and very few implementations can be found. Besides, the systems in the literature lack scalability. In this paper we show all the steps followed to perform the design, research and development of a wireless multisensor network which mixes sensors with IP cameras in a wireless network in order to detect and verify fire in rural and forest areas of Spain. We have studied how many cameras, sensors and access points are needed to cover a rural or forest area, and the scalability of the system. We have developed a multisensor and when it detects a fire, it sends a sensor alarm through the wireless network to a central server. The central server selects the closest wireless cameras to the multisensor, based on a software application, which are rotated to the sensor that raised the alarm, and sends them a message in order to receive real-time images from the zone. The camera lets the fire fighters corroborate the existence of a fire and avoid false alarms. In this paper, we show the test performance given by a test bench formed by four wireless IP cameras in several situations and the energy consumed when they are transmitting. Moreover, we study the energy consumed by each device when the system is set up. The wireless sensor network could be connected to Internet through a gateway and the images of the cameras could be seen from any part of the world.
TL;DR: Results indicate that ABA response is finely tuned by the integrated action of these genes, which is required to prevent a constitutive response to endogenous ABA that might have a deleterious effect on growth and development in the absence of environmental stress.
Abstract: The phytohormone abscisic acid (ABA) is a key regulator of plant growth and development as well as plant responses to situations of decreased water availability. Protein phosphatases type 2C (PP2Cs) from group A, which includes the ABI1/HAB1 and PP2CA branches, are key negative regulators of ABA signaling. Specifically, HAB1, ABI1, ABI2, and PP2CA have been shown to affect both seed and vegetative responses to ABA. To further understand their contribution to ABA signaling and to unravel possible genetic interactions and functional redundancy among them, we have generated different combinations of double and triple mutants impaired in these PP2Cs. Interestingly, hab1-1pp2ca-1 and abi1-2pp2ca-1 double mutants showed reduced water loss and enhanced resistance to drought stress, which further supports the role of PP2CA in vegetative responses to ABA. Two triple hab1-1abi1-2abi2-2 and hab1-1abi1-2pp2ca-1 mutants were generated, which showed an extreme response to exogenous ABA, impaired growth, and partial constitutive response to endogenous ABA. Thus, transcriptomic analysis revealed a partial up-regulation/down-regulation of a subset of ABA-responsive genes in both triple mutants in the absence of exogenous ABA. Comparison of ABA responses in the different pp2c mutants showed that a progressive increase in ABA sensitivity could be obtained through combined inactivation of these PP2Cs. These results indicate that ABA response is finely tuned by the integrated action of these genes, which is required to prevent a constitutive response to endogenous ABA that might have a deleterious effect on growth and development in the absence of environmental stress.
TL;DR: In this paper, a review of the work carried out within the EU Network of Excellence ISIS on radio-over-fiber systems for the support of current and emerging wireless networks is reviewed.
Abstract: Some of the work carried out within the EU Network of Excellence ISIS on radio-over-fiber systems for the support of current and emerging wireless networks is reviewed. Direct laser modulation and externally modulated links have been investigated, and demonstrations of single-mode fiber and multimode fiber systems are presented. The wireless networks studied range from personal area networks (such as ZigBee and ultrawideband) through wireless local area networks to wireless metropolitan area networks (WiMAX) and third-generation mobile communications systems. The performance of the radio-over-fiber transmission is referenced to the specifications of the relevant standard, protocol operation is verified, and complete network demonstrations are implemented.
TL;DR: In this article, a high molecular weight chitosan (CH) and different concentrations of oleic acid (OA) were used to evaluate the properties of FFD particles in terms of rheological properties, surface tension, particle size distribution and potential.
TL;DR: A review of the literature related to supply chain planning methods under uncertainty is presented in this paper, where the main objective is to provide the reader with a starting point for modelling supply chain under uncertainty applying quantitative approaches.
Abstract: Managing uncertainty is a main challenge within supply chain management. Therefore, it is expected that those supply chain planning methods which do not include uncertainty obtain inferior results if compared with models that formalise it implicitly. This article presents a review of the literature related to supply chain planning methods under uncertainty. The main objective is to provide the reader with a starting point for modelling supply chain under uncertainty applying quantitative approaches. We have defined a taxonomy to classify models from 103 bibliographic references dated 1988–2007. Finally, some conclusions about the works analysed have been drawn and future lines of research have been identified.
TL;DR: The results suggest that temperature regulates hypocotyl growth by individually impinging on several elements of a pre-existing network of signaling pathways involving auxin, BRs, GAs, and PIF4.
Abstract: Successful plant survival depends upon the proper integration of information from the environment with endogenous cues to regulate growth and development. We have investigated the interplay between ambient temperature and hormone action during the regulation of hypocotyl elongation, and we have found that gibberellins (GAs) and auxin are quickly and independently recruited by temperature to modulate growth rate, whereas activity of brassinosteroids (BRs) seems to be required later on. Impairment of GA biosynthesis blocked the increased elongation caused at higher temperatures, but hypocotyls of pentuple DELLA knockout mutants still reduced their response to higher temperatures when BR synthesis or auxin polar transport were blocked. The expression of several key genes involved in the biosynthesis of GAs and auxin was regulated by temperature, which indirectly resulted in coherent variations in the levels of accumulation of nuclear GFP-RGA (repressor of GA1) and in the activity of the DR5 reporter. DNA microarray and genetic analyses allowed the identification of the transcription factor PIF4 (phytochrome-interacting factor 4) as a major target in the promotion of growth at higher temperature. These results suggest that temperature regulates hypocotyl growth by individually impinging on several elements of a pre-existing network of signaling pathways involving auxin, BRs, GAs, and PIF4.
TL;DR: A fuzzy mathematical programming model for supply chain planning which considers supply, demand and process uncertainties, formulated as a fuzzy mixed-integer linear programming model where data are ill-known and modelled by triangular fuzzy numbers is proposed.
TL;DR: The state-of-the-art of SGAW biosensors for the detection of pathogens are described, being this topic an issue of extremely importance for the human health.
Abstract: This review presents a deep insight into the Surface Generated Acoustic Wave (SGAW) technology for biosensing applications, based on more than 40 years of technological and scientific developments. In the last 20 years, SGAWs have been attracting the attention of the biochemical scientific community, due to the fact that some of these devices - Shear Horizontal Surface Acoustic Wave (SH-SAW), Surface Transverse Wave (STW), Love Wave (LW), Flexural Plate Wave (FPW), Shear Horizontal Acoustic Plate Mode (SH-APM) and Layered Guided Acoustic Plate Mode (LG-APM) - have demonstrated a high sensitivity in the detection of biorelevant molecules in liquid media. In addition, complementary efforts to improve the sensing films have been done during these years. All these developments have been made with the aim of achieving, in a future, a highly sensitive, low cost, small size, multi-channel, portable, reliable and commercially established SGAW biosensor. A setup with these features could significantly contribute to future developments in the health, food and environmental industries. The second purpose of this work is to describe the state-of-the-art of SGAW biosensors for the detection of pathogens, being this topic an issue of extremely importance for the human health. Finally, the review discuses the commercial availability, trends and future challenges of the SGAW biosensors for such applications.
TL;DR: In this article, gold nanoparticles on nanoparticulated ceria have been used to selectively convert 5-Hydroxymethyl-2-furfural (HMF) into DMF under mild conditions (65-130°C, 10 bar O 2 ) in the absence of any base, by using gold nano-articles.
TL;DR: In this article, the impact of the incorporation of TTO into the HPMC matrix, the water sorption isotherms, water vapour permeability (WVP), mechanical and optical properties of the dry films were evaluated.
10 Aug 2009
TL;DR: This tutorial shows the reader how to use Maude-NPA, and how it works, and also gives some of the theoretical background behind the tool.
Abstract: In this tutorial, we give an overview of the Maude-NRL Protocol Analyzer (Maude-NPA), a tool for the analysis of cryptographic protocols using functions that obey different equational theories. We show the reader how to use Maude-NPA, and how it works, and also give some of the theoretical background behind the tool.
TL;DR: This paper describes the design of new controlled delivery systems consisting of a mesoporous support functionalized on the pore outlets with a certain hapten able to interact with an antibody that acts as a nanoscopic cap.
Abstract: This paper describes the design of new controlled delivery systems consisting of a mesoporous support functionalized on the pore outlets with a certain hapten able to interact with an antibody that acts as a nanoscopic cap. The opening protocol and delivery of the entrapped guest is related by a displacement reaction involving the presence in the solution of the antigen to which the antibody is selective. As a proof-of-the-concept, the solid MCM-41 was selected as support and was loaded with the dye [Ru(bipy)3]Cl2. Then a suitable derivative of the hapten 4-(4-aminobenzenesulfonylamino)benzoic acid was anchored on the outer surface of the mesoporous support (solid S1). Finally the pores were capped with a polyclonal antibody for sulfathiazole (solid S1-AB). Delivery of the dye in the presence of a family of sulfonamides was studied in phosphate-buffered saline (PBS; pH 7.5). A selective uncapping of the pores and dye delivery was observed for sulfathiazole. This delivery behavior was compared with that sh...
TL;DR: Five illustrative examples of SCO systems, published during the past twelve months, showing new aspects of the unique and very appealing behaviour of these molecular switches, which may find interesting applications in the near future.
Abstract: Over the past five years, the spin-crossover (SCO) phenomenon has experienced a clear new lease of interest from the scientific community coinciding with the recent publication of remarkable new advances. This perspective paper describes five illustrative examples of SCO systems, published during the past twelve months, showing new aspects of the unique and very appealing behaviour of these molecular switches, which may find interesting applications in the near future.