Testing Choice Experiment for Benefit Transfer

Benefit transfer is a cost-effective method for estimating the value of environmental goods that relies on information obtained in previous studies. The multi-attribute approach of choice experiment should provide advantages in terms of benefit transfer allowing differences in environmental improvements between sites as well as differences in socio-economic and attitude characteristics between respondent populations. Furthermore, choice experiment allows the estimation of implicit prices and the welfare change for many scenarios. If the transferability of these values is confirmed, that would be good news for benefit transfer practitioners. This paper investigates the capability of choice experiment method to be used in environmental benefit transfer.choice experiment, benefit transfer, soil erosion, Research Methods/ Statistical Methods, Q30,

Saber hacer, saber usar: reflexiones a partir de una experiencia didáctica con armas prehispánicas

En los últimos años, los autores de este trabajo llevaron a cabo diferentes aproximaciones a algunos sistemas de armas prehispánicas, como lanzadera y boleadora. El estudio de estas tecnologías fue considerado a partir de sus cadenas operativas, para lo cual se integraron los datos aportados por la replicación experimental y los registros material y documental. En base a esta experiencia previa, en el transcurso del VI Congreso de Arqueología de la Región Pampeana Argentina los autores fueron invitados a coordinar un taller de uso de armas prehispánicas. A partir de la experiencia práctica en el empleo de la lanzadera y las boleadoras se buscó que los participantes tuvieran un acercamiento inicial a estas tecnologías del pasado, con la intención de evaluar los posibles alcances y limitaciones de la experimentación sobre sistemas de armas en función de su uso; así como también su potencial para la interpretación del registro material en diferentes contextos arqueológicos.In recent years, the authors carried out different approaches to some prehispanic weapons systems such as shuttles and bolas. The study of these technologies was considered from its chaînes opératoires. To do so, data provided by experimental replication, written sources and material records were integrated. From this previous experience, during the VI Congreso de Arqueología de la Región Pampeana Argentina, authors were invited to organize a workshop on the use of prehispanic weapons. Through practice in the use of the shuttle and the bolas it sought that participants to have an initial approach to these past technologies, in order to assess the potential scope and limitations of experimentation on weapons systems in terms of their use; as well as its potential for interpreting material record in archaeological contexts.Fil: Colombo, Mariano Jorge. Provincia de Buenos Aires. Municipalidad de Necochea. Museo de Ciencias Naturales de Necochea; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vecchi, Rodrigo Javier. Universidad Nacional del Sur. Departamento de Humanidades; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

On the origin of the jet-like radio/X-ray morphology of G290.1-0.8

The origin and evolution of supernova remnants of the mixed-morphology class is not well understood. Several remnants present distorted radio or X-ray shells with jet-like structures. G290.1-0.8 (MSH 11-61A) belongs to this class. We aim to investigate the nature of this supernova remnant in order to unveil the origin of its particular morphology. We based our work on the study of the X-ray emitting plasma properties and the conditions imposed by the cold interstellar medium where the remnant expanded. We use archival radio, HI line data and X-ray observations from XMM-Newton and Chandra observatories, to study G290.1-0.8 and its surrounding medium. Spatially resolved spectral analysis and mean photon energy maps are used to obtain physical and geometrical parameters of the source. Radio continuum and HI line maps give crucial information to understand the radio/X-ray morphology. The X-ray images show that the remnant presents two opposite symmetric bright spots on a symmetry axis running towards the NW-SE direction. Spectral analysis and mean photon energy maps confirm that the physical conditions of the emitting plasma are not homogeneous throughout the remnant. In fact, both bright spots have higher temperatures than the rest of the plasma and its constituents have not reached ionization equilibrium yet. HI line data reveal low density tube-like structures aligned along the same direction. This evidence supports the idea that the particular X-ray morphology observed is a direct consequence of the structure of the interstellar medium where the remnant evolved. However, the possibility that an undetected point-like object, as a neutron star, exists within the remnant and contributes to the X-ray emission cannot be discarded. Finally, we suggest that a supernova explosion due to the collapse of a high-mass star with a strong bipolar wind can explain the supernova remnant morphology.Comment: 8 pages, 6 figures. Accepted for publication in A&

A statistical criterion to establish normal ranges for age in a contrast sensitivity function test

In a previous work (Optica Applicata 39(2)) we established the characteristics that a computer based CSF measurement system has to have to be used in the opthalmological clinic. In order to obtain a generalized use of CSF in clinics and as a screening tool, the necessity to incorporate a normality range by age was also suggested. It will also be important to establish how many reference curves are necessary, because in the last decades, different ranges have been presented in the literature. In the present work, our purpose was to show how to distribute the observers in terms of the statistical variations of CSF as a function of age in a normal population of healthy eyes. We then evaluated the utility of these curves in the detection of vision problems and, finally, the possibility of using them as screening tool considering a reduced number of spatial frequencies. We used a computer-based CSF measurement system to present sinusoidal gratings whose values range from 1 to 24 cycles per degree. Three groups of subjects were considered. Group 1 consisted of 55 subjects grouped in five age ranges: 20-29 (M=25, SD=3.5), 20 eyes; 30-39 (M=34, SD=1.7), 20 eyes; 40-49 (M=44, SD=3.6), 22 eyes; 50-59 (M=55, SD=2.9), 20 eyes; and 60-69 (M=66, SD=2.8), 21 eyes and served as a normal reference and its measurements were performed in a vision laboratory. Group 2 was made up of 29 subjects between the ages of 20 and 50 (M= 32, SD=9.2) who voluntarily attended the Ophthalmology Service of the local Medical School for the first time because they recognized having some difficulty with their vision. Measurements were performed in a consulting room. Group 3 consisted of 56 subjects between the ages of 20 and 50 (M=31, SD=8.1) who were visitors to a Technology Fair, a noisy and visually polluted environment. From the statistical analysis we obtained two ranges of normality, based on significant differences that appear around the age of 50. As we were interested in evaluating if this separation could increase the sensitivity of the test, we also performed a series of measurements in a clinical environment. As an interesting possibility of usage of a vision test is screening, we also measured people in conditions relatively different to those found in laboratories or clinics. We observed that this division into two ranges allows a better discrimination, especially for young adults. Measurements show an improvement of 22% in the detection of vision anomalies.Fil: Santillán, Javier Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucuman. Instituto de Investigacion En Luz, Ambiente y Vision; Argentina. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnologia. Departamento de Luminotecnia, Luz y Vision; ArgentinaFil: Issolio, Luis Alberto. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnologia. Departamento de Luminotecnia, Luz y Vision; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucuman. Instituto de Investigacion En Luz, Ambiente y Vision; ArgentinaFil: Colombo, Elisa Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucuman. Instituto de Investigacion En Luz, Ambiente y Vision; Argentina. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnologia. Departamento de Luminotecnia, Luz y Vision; Argentin

New insights into enterocin CRL35: mechanism of action and immunity revealed by heterologous expression in Escherichia coli

The role of the class IIa bacteriocin membrane receptor protein remains unclear, and the following two different mechanisms have been proposed: the bacteriocin could interact with the receptor changing it to an open conformation or the receptor might act as an anchor allowing subsequent bacteriocin insertion and membrane disruption. Bacteriocin-producing cells synthesize an immunity protein that forms an inactive bacteriocin–receptor–immunity complex. To better understand the molecular mechanism of enterocin CRL35, the peptide was expressed as the suicidal probe EtpM-enterocin CRL35 in Escherichia coli, a naturally insensitive microorganism since it does not express the receptor. When the bacteriocin is anchored to the periplasmic face of the plasma membrane through the bitopic membrane protein, EtpM, E. coli cells depolarize and die. Moreover, co-expression of the immunity protein prevents the deleterious effect of EtpM-enterocin CRL35. The binding and anchoring of the bacteriocin to the membrane has demonstrated to be a sufficient condition for its membrane insertion. The final step of membrane disruption by EtpM-enterocin CRL35 is independent from the receptor, which means that the mannose PTS might not be involved in the pore structure. In addition, the immunity protein can protect even in the absence of the receptor.Fil: Barraza, Daniela Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Ríos Colombo, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Galván, Adriana Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Acuña, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Minahk, Carlos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Bellomio, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Chalon, Miriam Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin

Evidence of thermal transport anisotropy in stable glasses of vapour deposited organic molecules

Vapour-deposited organic glasses are currently in use in many optoelectronic devices. Their operation temperature is limited by the glass transition temperature of the organic layers and thermal management strategies become increasingly important to improve the lifetime of the device. Here we report the unusual finding that molecular orientation heavily influences heat flow propagation in glassy films of small molecule organic semiconductors. The thermal conductivity of vapour-deposited thin-film semiconductor glasses is anisotropic and controlled by the deposition temperature. We compare our data with extensive molecular dynamics simulations to disentangle the role of density and molecular orientation on heat propagation. Simulations do support the view that thermal transport along the backbone of the organic molecule is strongly preferred with respect to the perpendicular direction. This is due to the anisotropy of the molecular interaction strength that limit the transport of atomic vibrations. This approach could be used in future developments to implement small molecule glassy films in thermoelectric or other organic electronic devices.Comment: main manuscript: 17 pages and 7 figures; supplementary material: 6 pages and 7 figure

An energy-momentum method for ordinary differential equations with an underlying kk-polysymplectic manifold

This work presents a comprehensive review of the $k$-polysymplectic Marsden-Weinstein reduction theory, rectifying prior errors and inaccuracies in the literature while introducing novel findings. It also emphasises the genuine practical significance of seemingly minor technical details. On this basis, we introduce a novel $k$-polysymplectic energy-momentum method, new related stability analysis techniques, and apply them to Hamiltonian systems of ordinary differential equations relative to a $k$-polysymplectic manifold. We provide detailed examples of both physical and mathematical significance, including the study of complex Schwarz equations related to the Schwarz derivative, a series of isotropic oscillators, integrable Hamiltonian systems, quantum oscillators with dissipation, affine systems of differential equations, and polynomial dynamical systems.Comment: 40 page

X-ray emission from stellar jets by collision against high-density molecular clouds: an application to HH 248

We investigate the plausibility of detecting X-ray emission from a stellar jet that impacts against a dense molecular cloud. This scenario may be usual for classical T Tauri stars with jets in dense star-forming complexes. We first model the impact of a jet against a dense cloud by 2D axisymmetric hydrodynamic simulations, exploring different configurations of the ambient environment. Then, we compare our results with XMM-Newton observations of the Herbig-Haro object HH 248, where extended X-ray emission aligned with the optical knots is detected at the edge of the nearby IC 434 cloud. Our simulations show that a jet can produce plasma with temperatures up to 10 MK, consistent with production of X-ray emission, after impacting a dense cloud. We find that jets denser than the ambient medium but less dense than the cloud produce detectable X-ray emission only at the impact onto the cloud. From the exploration of the model parameter space, we constrain the physical conditions (jet density and velocity, cloud density) that reproduce well the intrinsic luminosity and emission measure of the X-ray source possibly associated with HH 248. Thus, we suggest that the extended X-ray source close to HH 248 corresponds to the jet impacting on a dense cloud.Comment: Accepted for publication in ApJ. (12 pages, 12 figures

What characteristics a clinical CSF system has to have?

We discuss the characteristics a system to measure the contrast sensitivity function (CSF) in the ophthalmologic clinic has to have. We propose that this system should be computer based in order to assure flexibility and precision. Besides the original calibration, this equipment needs an auxiliary system to keep the working conditions allowing periodical gamma corrections. We try a calibration method based on visual comparisons and show that it is valid and simple. We propose to use an adaptive psychophysical method to obtain contrast thresholds that assure a good compromise between precision and duration of the whole test. Finally, we propose that the system has to have its own normality curves for the different age ranges allowing the practitioner to perform clinical evaluations. Summing up, we can say that taking into account the above issues, the fidelity of the stimuli will be guaranteed and the challenges entailed in its transference to the clinic will be overcome.Fil: Colombo, Elisa Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Luminotecnia, Luz y Visión; ArgentinaFil: Issolio, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Luminotecnia, Luz y Visión; ArgentinaFil: Santillán, Javier Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Luminotecnia, Luz y Visión; ArgentinaFil: Rolando Aguirre. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentin

Virtual reality for anxiety and stress-related disorders: A SWOT analysis

Virtual Reality (VR) Therapy has emerged in the 90s as an appealing way of delivering exposure treatment. Throughout these years, ample evidence has been published. Although there is an agreed consensus regarding its efficacy, currently a quick shift in the field is being experienced, especially due to the advent of off-the-shelf technology that is greatly facilitating its dissemination. In this context, theoretical discussions of the field appear as an important action in order to take stock of the mounting evidence that has been produced and the main challenges for the coming future. To stimulate the discussion in a burgeoning field, a SWOT analysis is proposed, which may help to map the field of VR therapy for anxiety and stress-related disorders. Overall, it is undoubted that VR appears as a well-established technology for the treatment of ASRD and the main challenges are in line with the possibility of hurdling the same obstacles that the whole field of clinical psychology and psychotherapy has to deal with: How to bridge the gap between research and clinical practice