Measuring Consumer Acceptance and Willingness-To-Pay for Specialty Tomatoes: Impact of Product, Taste, and Health Features

The increasing public health awareness and the promotion given to healthy eating habits as a measure to prevent obesity and chronic diseases have pushed consumer’s attention towards differentiated products. Many of the differentiated products, such as those with environmental, local, and other health and quality claims, are categorized as credence goods. Credence attributes, such as nutritional characteristics, are unobserved by consumers even after consumption, making the use of information crucial for marketing the benefits of such products. While there have been numerous studies examining the potential impacts of these attributes on consumer demand, few studies combine consumer valuation of credence attributes with sensory analysis of products and information treatments. This study attempts to shed more light on this area by considering both the impact of various attributes on consumer demand and the consistency in consumer valuation under different information treatments. The information treatments refer to tasting, health information, and the location of origin and production system of the products. A non-hypothetical second-price Vickrey auction was conducted in the Bryan-College Station area of Texas in order to collect the data. Several econometric models were developed to estimate consumers’ willingness-to-pay (WTP); however, special attention was paid to the random parameters tobit model as it accounts for unobserved individual heterogeneity as well as bid-censoring. Results show that knowledge of location of origin of tomatoes does have an impact on consumer valuation. The same holds true for the taste attribute (experience) and the health attribute (credence). Each information treatment was applied to several products and some treatments had contradictory results between products which prevented generalizing the effects of that treatment. In addition, estimates indicate there exists unobserved heterogeneity in valuations across individuals. Finally, using a Latent Class Analysis, consumers were segmented based on health-related behaviors, and the differences in the valuation of products and information treatments among those classes were measured using random parameters tobit models. Two latent classes were found and characterized as: “Health Conscious”, and “Health Redeemers”. The findings indicate that the classes differed significantly in terms of their preferences, willingness to pay, socio-economic profile, and health-driven motivations

Shaping plasmon beams via the controlled illumination of finite-size plasmonic crystals

Plasmonic crystals provide many passive and active optical functionalities, including enhanced sensing, optical nonlinearities, light extraction from LEDs and coupling to and from subwavelength waveguides. Here we study, both experimentally and numerically, the coherent control of SPP beam excitation in finite size plasmonic crystals under focussed illumination. The correct combination of the illuminating spot size, its position relative to the plasmonic crystal, wavelength and polarisation enables the efficient shaping and directionality of SPP beam launching. We show that under strongly focussed illumination, the illuminated part of the crystal acts as an antenna, launching surface plasmon waves which are subsequently filtered by the surrounding periodic lattice. Changing the illumination conditions provides rich opportunities to engineer the SPP emission pattern. This offers an alternative technique to actively modulate and control plasmonic signals, either via micro- and nano-electromechanical switches or with electro- and all-optical beam steering which have direct implications for the development of new integrated nanophotonic devices, such as plasmonic couplers and switches and on-chip signal demultiplexing. This approach can be generalised to all kinds of surface waves, either for the coupling and discrimination of light in planar dielectric waveguides or the generation and control of non-diffractive SPP beams

Dynamic Behavior of Thermally Coupled Distillation Configurations for the Separation of Multicomponent Mixtures

Control properties of thermally coupled distillation arrangements for the separation of multicomponent mixtures were compared to those of conventional distillation sequences. Seven thermally coupled schemes were investigated. The preliminary steady – state design of complex schemes was obtained by starting from a conventional distillation sequences and then optimizing for minimum energy consumption (energy-efficient designs). The dynamic behavior of the sequences considered were obtained by using the singular value decomposition technique at zero frequency. It was found that, in general, the complex schemes present theoretical control properties similar or better to those of conventional distillation sequences. This result is significant because it lets one establish that the energy savings predicted for thermally coupled distillation sequences are achieved without introducing additional control problems

Advanced therapies for the treatment of hemophilia: future perspectives

Monogenic diseases are ideal candidates for treatment by the emerging advanced therapies, which are capable of correcting alterations in protein expression that result from genetic mutation. In hemophilia A and B such alterations affect the activity of coagulation factors VIII and IX, respectively, and are responsible for the development of the disease. Advanced therapies may involve the replacement of a deficient gene by a healthy gene so that it generates a certain functional,structural or transport protein (gene therapy); the incorporation of a full array of healthy genes and proteins through perfusion or transplantation of healthy cells (cell therapy); or tissue transplantation and formation of healthy organs (tissue engineering). For their part, induced pluripotent stem cells have recently been shown to also play a significant role in the fields of cell therapy and tissue engineering.Hemophilia is optimally suited for advanced therapies owing to the fact that, as a monogenic condition, it does not require very high expression levels of a coagulation factor to reach moderate disease status. As a result, significant progress has been possible with respect to these kinds of strategies, especially in the fields of gene therapy (by using viral and non-viral vectors) and cell therapy (by means of several types of target cells). Thus, although still considered a rare disorder, hemophilia is now recognized as a condition amenable to gene therapy, which can be administered in the form of lentiviral and adeno-associated vectors applied to adult stem cells, autologous fibroblasts, platelets and hematopoietic stem cells; by means of non-viral vectors; or through the repair of mutations by chimeric oligonucleotides. In hemophilia, cell therapy approaches have been based mainly on transplantation of healthy cells (adult stem cells or induced pluripotent cell-derived progenitor cells)in order to restore alterations in coagulation factor expression

Boundary effects in finite size plasmonic crystals: Focusing and routing of plasmonic beams for optical communications

Plasmonic crystals, which consist of periodic arrangements of surface features at a metal-dielectric interface, allow the manipulation of optical information in the form of surface plasmon polaritons. Here we investigate the excitation and propagation of plasmonic beams in and around finite size plasmonic crystals at telecom wavelengths, highlighting the effects of the crystal boundary shape and illumination conditions. Significant differences in broad plasmonic beam generation by crystals of different shapes are demonstrated, while for narrow beams, the propagation onto the smooth metal film is less sensitive to the crystal boundary shape. We show that by controlling the boundary shape, the size and the excitation beam parameters, directional control of propagating plasmonic modes and associated beam parameters such as angular beam splitting, focusing power and beam width can be efficiently achieved. This provides a promising route for robust and alignment-independent integration of plasmonic crystals with optical communication components

Induced Pluripotent Stem Cells: Therapeutic Applications in Monogenic and Metabolic Diseases, and Regulatory and Bioethical Considerations

Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasTRUEpu

Memoria de la Federación de Sindicatos Agrícolas Católicos de la Diócesis de Segovia, leída por el secretario D. Antonio Sanz, en la asamblea celebrada por esta Federación el día 25 de noviembre de 1921

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Comment on `Renormalization-Group Calculation of the Dependence on Gravity of the Surface Tension and Bending Rigidity of a Fluid Interface'

It is shown that the interface model introduced in Phys. Rev. Lett. 86, 2369 (2001) violates fundamental symmetry requirements for vanishing gravitational acceleration $g$, so that its results cannot be applied to critical properties of interfaces for $g\to 0$.Comment: A Comment on a recent Letter by J.G. Segovia-L\'opez and V. Romero-Roch\'{\i}n, Phys. Rev. Lett.86, 2369 (2001). Latex file, 1 page (revtex