266 research outputs found
Innovativeness and network competence : an integration and empirical examination
This paper reports a study of the interdependence of network competence and
innovativeness in a product innovation context. Based on a systematic review on
innovation literature, authors define two review constructs for innovativeness and
network competence. The dimensions of both concepts were validated through a sample
of 164 manufacturing Portuguese firms, which provides interesting results concerning the behavior of Portuguese manufacturing companies at the level of network innovation
The dimensions of purchasing competence: a synthesis from literature
Organizational buying behavior has been dramatically changing due to transformations on the nature of industrial competition. This changing environment implies great demands to companies to remain competitive. As firms
recognize the purchasing function as an important resource for obtaining high
quality levels, fast deliveries and cost savings, it reveals opportunities for the
purchasing management to become a business key contributor. This paper
presents a critical literature review concerning the new strategic role for
purchasing. We develop a construct of purchasing competence using three
dimensions identified from literature: purchasing interaction, purchasing
importance, and purchasing task execution
The dimensions of purchasing competence
As firms recognize the purchasing function as an important resource for obtaining high
quality levels, fast deliveries and cost savings, it reveals opportunities for the purchasing management to become a key contributor. The new product development is one example where acquisition capabilities may confirm to be particularly critical. This paper presents a construct of purchasing competence using three dimensions identified from literature: purchasing interaction, purchasing importance, and purchasing task execution. We discuss the dimensions based on a critical literature review concerning the new strategic role for purchasing. The dimensions of our purchasing competence construct were validated through a sample of 164 manufacturing Portuguese firms
Comparação entre diferentes formas de fornecer micronutrientes às sementes de feijão.
O presente trabalho teve como objetivo comparar diferentes formas de aplicação dos micronutrientes: Boro (B), Cobalto (Co) e Molibdênio (Mo) em sementes de feijão. As formas de aplicação avaliadas foram: recobrimento de sementes em leito de jorro, recobrimento em sacos plásticos e o fornecimento via sulco
Flooding tolerance and cell wall alterations in maize mesocotyl during hypoxia.
ABSTRACT - This research aimed to characterize the tolerance to flooding and alterations in pectic and hemicellulose fractions from mesocotyl of maize tolerant to flooding when submitted to hypoxia. In order to characterize tolerance seeds from maize cultivars Saracura BRS-4154 and BR 107 tolerant and sensitive to low oxygen levels, respectively, were set to germinate. Plantlet survival was evaluated during five days after having been submitted to hypoxia. After fractionation with ammonium oxalate 0.5% (w/v) and KOH 2M and 4M, Saracura BRS-4154 cell wall was obtained from mesocotyl segments with different damage intensities caused by oxygen deficiency exposure. The cell wall fractions were analyzed by gel filtration and gas chromatography, and also by Infrared Spectrum with Fourrier Transformation (FTIR). The hypoxia period lasting three days or longer caused cell lysis and in advanced stages plant death. The gelic profile from pectic, hemicellulose 2M and 4M fractions from samples with translucid and constriction zone showed the appearance of low molecular weight compounds, similar to glucose. The main neutral sugars in pectic and hemicellulose fractions were arabinose, xilose and mannose. The FTIR spectrum showed a gradual decrease in pectic substances from mesocotyl with normal to translucid and constriction appearance respectively RESUMO - Objetivou-se caracterizar a tolerancia ao alagamento e alteracoes nas fracoes pecticas e hemicelulosicas de mesocotilos de milho submetidos a hipoxia. Sementes de milho cultivar Saracura BRS-4154 e BR 107, tolerante e sensivel a hipoxia, respectivamente, foram submetidas a germinacao e a sobrevivencia das plantulas em condicoes de hipoxia, foi avaliada durante cinco dias. O material de parede celular, obtido de segmentos de mesocotilos da cultivar Saracura BRS-4154 com diferentes intensidades de danos causados por hipoxia, foi submetido a fracionamento com oxalato de amonio 0,5% e KOH 2M e 4M. As fracoes de parede celular obtidas foram analisadas por cromatografia em gel, cromatografia gasosa e espectro de infravermelho com transformacao dos dados pela serie de Fourrier (FTIR). Periodos de hipoxia superiores a tres dias causaram a lise celular (aparencia translucida),e, em estadios mais avancados, a morte das plantas. O perfil gelico das fracoes pecticas, hemicelulose 2M e 4M das amostras de mesocotilos translucidos e com constricao apresentaram compostos de baixos pesos moleculares semelhantes a glicose. Os principais acucares neutros nas fracoes pecticas e hemicelulosicas foram arabinose, xilose e manose. O espectro de FTIR mostrou um decrescimo gradual nas substancias pecticas do mesocotilo com aparencia normal, para translucido e constricao respectivamente
Three-Dimensional Simulations of Jets from Keplerian Disks: Self--Regulatory Stability
We present the extension of previous two-dimensional simulations of the
time-dependent evolution of non-relativistic outflows from the surface of
Keplerian accretion disks, to three dimensions. The accretion disk itself is
taken to provide a set of fixed boundary conditions for the problem. The 3-D
results are consistent with the theory of steady, axisymmetric, centrifugally
driven disk winds up to the Alfv\'en surface of the outflow. Beyond the
Alfv\'en surface however, the jet in 3-D becomes unstable to non-axisymmetric,
Kelvin-Helmholtz instabilities. We show that jets maintain their long-term
stability through a self-limiting process wherein the average Alfv\'enic Mach
number within the jet is maintained to order unity. This is accomplished in at
least two ways. First, poloidal magnetic field is concentrated along the
central axis of the jet forming a ``backbone'' in which the Alfv\'en speed is
sufficiently high to reduce the average jet Alfv\'enic Mach number to unity.
Second, the onset of higher order Kelvin-Helmholtz ``flute'' modes (m \ge 2)
reduce the efficiency with which the jet material is accelerated, and transfer
kinetic energy of the outflow into the stretched, poloidal field lines of the
distorted jet. This too has the effect of increasing the Alfv\'en speed, and
thus reducing the Alfv\'enic Mach number. The jet is able to survive the onset
of the more destructive m=1 mode in this way. Our simulations also show that
jets can acquire corkscrew, or wobbling types of geometries in this relatively
stable end-state, depending on the nature of the perturbations upon them.
Finally, we suggest that jets go into alternating periods of low and high
activity as the disappearance of unstable modes in the sub-Alfv\'enic regime
enables another cycle of acceleration to super-Alfv\'enic speeds.Comment: 57 pages, 22 figures, submitted to Ap
Thermo-responsive microemulsions containing deep eutectic-based antibiotic formulations for improved treatment of resistant bacterial ocular infections
The rise of antibiotic resistant strains, as methicillin-resistant Staphylococcus aureus (MRSA), challenges the current treatment of infections. In the case of ocular infections, antibiotic eye drops are commonly prescribed. However, their efficacy is usually compromised by the low viscosity of these formulations and the eye drainage. To overcome these drawbacks, deep eutectic solvent (DES)-based microemulsions with thermo-responsive character, that increase their viscosity upon contact with the eye have been developed. Using betaine-based DES aqueous solutions, it is possible to increase up to 140-fold the water solubility of the antibiotic chloramphenicol, typically used in ocular infections. The DES solutions containing the antibiotic are applied as water phases in water-in-oil-in-water (w/o/w) microemulsions, being stable up to 3 months. Furthermore, a sustained-release and a higher permeation of the antibiotic through the cornea than that of commercialized eye drops is achieved, while presenting comparable cytotoxicity profiles (cell viabilities > 88%). Higher antimicrobial activity and faster action of the antibiotic in case of infection with MRSA is observed compared to the commercialized formulations (7 log10 of inactivation in 48Â h vs 72Â h). Overall, these microemulsions comprising DES are a promising strategy to achieve higher antibiotic effectiveness in the treatment of resistant bacterial infections.info:eu-repo/semantics/publishedVersio
Exploring the genetic origin of Brazilian locally adapted breeds: admixture, population history and relationship with Portuguese and indicine cattle.
The domestication of bovines has given rise to distinct phenotypes resulting in diverse breeds worldwide. Subsequent artificial selection has further enriched the complexity and diversity to cattle sub-species adapting them to their various purposes and evolving environment. Among these cattle sub-species, native Portuguese cattle breeds are considered a repository of biodiversity shaped by genetic and environmental effects accumulated over the years. In Brazil, taurine animals were introduced between the 16th and 17th centuries by the European conquerors to be used for food, leather, and animal traction. Through generations of casual crossings in diverse ecosystems, these animals became adapted to a wide range of environments and displaying varying levels of phenotypic variability and improved fitness to local conditions, hereafter recognized as Iberian-derived Locally Adapted breeds. Thus, we focused in assess 13 cattle breeds representing two geographic origins: Portuguese Iberian cattle and Brazilian Iberian-derived Locally Adapted breeds. The aim is to understand the genetic architecture of Brazilian Iberian-derived Locally Adapted breeds and their potential relationship with Portuguese Iberian cattle and Brazilian indicine breeds. In our study, we observed varying extents of linkage disequilibrium across the evaluated breeds, along with differences in effective population size. Runs of homozygosity analyses revealed different genes associated with common traits, even within a cluster group. For instance, genes related to immune response, such as MAVS (Mertolenga), DTX (Barrosa), ˜ ZBTB16 (Brava de Lide), DUSP22 (Pantaneiro), and IL7R (Caracu Dairy and Caracu Beef). Overall, our results highlight that both populations studied, with their specificities, are crucial sources of animal genetic resource of animal genetic resources for food and agriculture
"Sustainable Cellulose Nanofibers-Mediated Synthesis of Uniform Spinel Zn-Ferrites Nanocorals for High Performances in Supercapacitors"
Spinel ferrites are versatile, low-cost, and abundant metal oxides with remarkable electronic and magnetic properties, which find several applications. Among them, they have been considered part of the next generation of electrochemical energy storage materials due to their variable oxidation states, low environmental toxicity, and possible synthesis through simple green chemical processing. However, most traditional procedures lead to the formation of poorly controlled materials (in terms of size, shape, composition, and/or crystalline structure). Thus, we report herein a cellulose nanofibers-mediated green procedure to prepare controlled highly porous nanocorals comprised of spinel Zn-ferrites. Then, they presented remarkable applications as electrodes in supercapacitors, which were thoroughly and critically discussed. The spinel Zn-ferrites nanocorals supercapacitor showed a much higher maximum specific capacitance (2031.81 F g−1 at a current density of 1 A g−1) than Fe2O3 and ZnO counterparts prepared by a similar approach (189.74 and 24.39 F g−1 at a current density of 1 A g−1). Its cyclic stability was also scrutinized via galvanostatic charging/discharging and electrochemical impedance spectroscopy, indicating excellent long-term stability. In addition, we manufactured an asymmetric supercapacitor device, which offered a high energy density value of 18.1 Wh kg−1 at a power density of 2609.2 W kg−1 (at 1 A g−1 in 2.0 mol L−1 KOH electrolyte). Based on our findings, we believe that higher performances observed for spinel Zn-ferrites nanocorals could be explained by their unique crystal structure and electronic configuration based on crystal field stabilization energy, which provides an electrostatic repulsion between the d electrons and the p orbitals of the surrounding oxygen anions, creating a level of energy that determines their final supercapacitance then evidenced, which is a very interesting property that could be explored for the production of clean energy storage devices
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