Methodology for informed design of sustainable tourism accommodation in Chile’s 9th Region the Gateway to Patagonia

AbstractLying between Chile's agricultural Central Valley and the wilds of Patagonia, the micro region of Araucanía Andina, is seeing a rise in both national and international tourism. With its snow-capped volcanoes, national parks, native forests and indigenous Mapuche culture, the region offers a wide range of activities to the Special Interest Tourist. The development of winter sports facilities and the growth in Northern Hemisphere visitors during the austral winter is extending the season, in what was previously predominantly a destination for Chilean summer holidaymakers. The tourism infrastructure must therefore respond to provide comfortable, energy efficient, sustainable accommodation during both the cold wet winters and short hot summers, meeting the expectations of an ever more demanding international market. The government funded research project “Sustainable Construction System and Energy Efficiency for Special Interest Tourist Infrastructure in the Araucanía Andina,” FONDEF Regional D10R1003, aims to provide the knowledge needed by the local tourist industry to achieve this goal. This paper presents the methodology and outcomes of the project, including the study of local vernacular architecture, post occupation evaluation of existing infrastructure, bioclimatic analysis, environmental and technical assessment of insulation and construction materials, digital simulation of proposals and the construction of physical test cells. The resulting proposal is a system of timber-framed walls, insulated with sheep's wool, finished externally with a ventilated façade. It is hoped that this prefabricated system, in conjunction with best practice guidelines for construction and management, should enable a sustainable future for the region's tourism. At the same time, the methodology provides a replicable template that has already been applied in other regions of the country

Space and time averaged quantum stress tensor fluctuations

We extend previous work on the numerical diagonalization of quantum stress tensor operators in the Minkowski vacuum state, which considered operators averaged in a finite time interval, to operators averaged in a finite spacetime region. Since real experiments occur over finite volumes and durations, physically meaningful fluctuations may be obtained from stress tensor operators averaged by compactly supported sampling functions in space and time. The direct diagonalization, via a Bogoliubov transformation, gives the eigenvalues and the probabilities of measuring those eigenvalues in the vacuum state, from which the underlying probability distribution can be constructed. For the normal-ordered square of the time derivative of a massless scalar field in a spherical cavity with finite degrees of freedom, analysis of the tails of these distributions confirms previous results based on the analytical treatment of the high moments. We find that the probability of large vacuum fluctuations is reduced when spatial averaging is included, but the tail still decreases more slowly than exponentially as the magnitude of the measured eigenvalues increases, suggesting vacuum fluctuations may not always be subdominant to thermal fluctuations and opening up the possibility of experimental observation under the right conditions.We extend previous work on the numerical diagonalization of quantum stress tensor operators in the Minkowski vacuum state, which considered operators averaged in a finite time interval, to operators averaged in a finite spacetime region. Since real experiments occur over finite volumes and durations, physically meaningful fluctuations may be obtained from stress tensor operators averaged by compactly supported sampling functions in space and time. The direct diagonalization, via a Bogoliubov transformation, gives the eigenvalues and the probabilities of measuring those eigenvalues in the vacuum state, from which the underlying probability distribution can be constructed. For the normal-ordered square of the time derivative of a massless scalar field in a spherical cavity with finite degrees of freedom, analysis of the tails of these distributions confirms previous results based on the analytical treatment of the high moments. We find that the probability of large vacuum fluctuations is reduced when spatial averaging is included, but the tail still decreases more slowly than exponentially as the magnitude of the measured eigenvalues increases, suggesting vacuum fluctuations may not always be subdominant to thermal fluctuations and opening up the possibility of experimental observation under the right conditions.Peer reviewe

Frequency Spectra Analysis of Space and Time Averaged Quantum Stress Tensor Fluctuations

Observing physical effects of large quantum stress tensor fluctuations requires knowledge of the interaction between the probe and the particles of the underlying quantum fields. The quantum stress tensor operators must first be averaged in time alone or space and time to confer meaningful results, the details of which may correspond to the physical measurement process. We build on prior results to characterize the particle frequencies associated with quantum fluctuations of different magnitudes. For the square of time derivatives of the massless scalar field in a spherical cavity, we find that these frequencies are bounded above in a power law behavior. Our findings provide a way identify the largest quantum fluctuation that may be probed in experiments relying on frequency-dependent interactions.Comment: 23 pages, 4 figures, 1 tabl

Vacuum Quantum Stress Tensor Fluctuations : A Diagonalization Approach

Large vacuum fluctuations of a quantum stress tensor can be described by the asymptotic behavior of its probability distribution. Here we focus on stress tensor operators which have been averaged with a sampling function in time. The Minkowski vacuum state is not an eigenstate of the time-averaged operator, but can be expanded in terms of its eigenstates. We calculate the probability distribution and the cumulative probability distribution for obtaining a given value in a measurement of the time-averaged operator taken in the vacuum state. In these calculations, we use the normal ordered square of the time derivative of a massless scalar field in Minkowski spacetime as an example of a stress tensor operator. We analyze the rate of decrease of the tail of the probability distribution for different temporal sampling functions, such as compactly supported functions and the Lorentzian function. We find that the tails decrease relatively slowly, as exponentials of fractional powers, in agreement with previous work using the moments of the distribution. Our results lead additional support to the conclusion that large vacuum stress tensor fluctuations are more probable than large thermal fluctuations, and may have observable effects

Gamma knife radiosurgery for arteriovenous malformations: general principles and preliminary results in a Swiss cohort.

Arteriovenous malformations (AVMs) are a type of vascular malformation characterised by an abnormal connection between arteries and veins, bypassing the capillary system. This absence of capillaries generates an elevated pressure (hyperdebit), in both the AVM and the venous drainage, increasing the risk of rupture. Management modalities are: observation, microsurgical clipping, endovascular treatment and radiosurgery. The former can be used alone or in the frame of a multidisciplinary approach. We review our single-institution experience with gamma knife radiosurgery (GKR) over a period of 5 years. The study was open-label, prospective and nonrandomised. Fifty-seven consecutive patients, benefitting from 64 GKR treatments, were included. All were treated with Leksell Gamma Knife Perfexion (Elekta Instruments, AB, Sweden) between July 2010 and August 2015. All underwent stereotactic multimodal imaging: standard digital subtraction angiography, magnetic resonance imaging and computed tomography angiography. We report obliteration rates, radiation-induced complications and haemorrhages during follow-up course. The mean age was 46 years (range 13-79 years). The mean follow-up period was 36.4 months (median 38, range 12-75 months). Most common pretherapeutic clinical presentation was haemorrhage (50%). The most common Pollock-Flickinger score was between 1.01 and 1.5 (46%) and Spetzler-Martin grade III (46%). In 39 (60.1%) of cases, GKR was performed as upfront therapeutic option. The mean gross target volume (GTV) was 2.3 ml (median 1.2, range 0.03-11.3 ml). Mean marginal dose was 22.4 Gy (median 24, range 18-24 Gy). The mean prescription isodose volume (PIV) was 2.9 ml (median 1.8, range 0.065-14.6 ml). The overall obliteration rates (all treatments combined) at 12, 24, 36, 48 and 60 months were 4.8, 16.9%, 37.4, 63.6 and 78.4%, respectively. The main predictive factors for complete obliteration were: higher mean marginal dose (23.3 vs 21.0 Gy), lower GTV (mean 1.5 vs 3.5 ml) and absence of previous embolisation (at 60 months 61.8% prior embolisation compared with 82.4% without prior embolisation) (for all p <0.05). Eight (14%) patients experienced complications after GKR. Overall definitive morbidity rate was 3.1%. No patient died from causes related to GKR. However, during the obliteration period, one case of extremely rare fatal haemorrhage occurred. Radiosurgery is a safe and effective treatment modality for intracranial AVMs in selected cases. It can be used as upfront therapy or in the frame of a combined management. Obliteration rates are high, with minimal morbidity. The treatment effect is progressive and subsequent and regular clinical and radiological follow-up is needed to evaluate this effect

Preserving normal facial nerve function and improving hearing outcome in large vestibular schwannomas with a combined approach: planned subtotal resection followed by gamma knife radiosurgery.

To perform planned subtotal resection followed by gamma knife surgery (GKRS) in a series of patients with large vestibular schwannoma (VS), aiming at an optimal functional outcome for facial and cochlear nerves. Patient characteristics, surgical and dosimetric features, and outcome were collected prospectively at the time of treatment and during the follow-up. A consecutive series of 32 patients was treated between July 2010 and June 2016. Mean follow-up after surgery was 29 months (median 24, range 4-78). Mean presurgical tumor volume was 12.5 cm3 (range 1.47-34.9). Postoperative status showed normal facial nerve function (House-Brackmann I) in all patients. In a subgroup of 17 patients with serviceable hearing before surgery and in which cochlear nerve preservation was attempted at surgery, 16 (94.1%) retained serviceable hearing. Among them, 13 had normal hearing (Gardner-Robertson class 1) before surgery, and 10 (76.9%) retained normal hearing after surgery. Mean duration between surgery and GKRS was 6.3 months (range 3.8-13.9). Mean tumor volume at GKRS was 3.5 cm3 (range 0.5-12.8), corresponding to mean residual volume of 29.4% (range 6-46.7) of the preoperative volume. Mean marginal dose was 12 Gy (range 11-12). Mean follow-up after GKRS was 24 months (range 3-60). Following GKRS, there were no new neurological deficits, with facial and hearing functions remaining identical to those after surgery in all patients. Three patients presented with continuous growth after GKRS, were considered failures, and benefited from the same combined approach a second time. Our data suggest that large VS management, with planned subtotal resection followed by GKRS, might yield an excellent clinical outcome, allowing the normal facial nerve and a high level of cochlear nerve functions to be retained. Our functional results with this approach in large VS are comparable with those obtained with GKRS alone in small- and medium-sized VS. Longer term follow-up is necessary to fully evaluate this approach, especially regarding tumor control

Chemistry in Context for engineering students at UCT: Transformation from a villain to a princess

The Universidad Católica de Temuco (Araucanía region, Chile) has experienced substantial changes in recent years: today, young people with a poor academic background, who are also digital natives, are enrolled in it. In this scenario, fostering deep learning in all students, the teachers have been given the task of implementing active learning methodologies with ICT incorporation. Specifically, the faculty that teaches “Chemistry in Context” to engineering students decided to transform (re-design) of this course, which included the implementation of active learning strategies such as the flipped classroom, instead of traditional lectures, and guided inquiry to change the laboratory work. This article explains how the new strategies were implemented, and it shows results which were obtained by contrasting students’ performance (based on the grades) before and after the transformation process. After the transformation, the approval rate nearly doubled and the dropout rate reduced from 40% to 17% in 2017. In the case of the laboratory work, although the tasks were more complex guided inquiry showed much better grades. These results can be attributed to the students working to build their learning, to the fact that the laboratory grade had a more significant percentage of the final grade and to the fact that students had to do all the experimental work as a mandatory activity otherwise they would fail the course. It was found that the flipped classroom will be successful if students value autonomous work and act accordingly. La Universidad Católica de Temuco (Araucanía, Chile) ha experimentado fuertes cambios en los años recientes: hoy, ingresan a ella jóvenes con un bajo capital académico, que, además, son “nativos digitales”. En este escenario, en pos de generar aprendizajes significativos en sus estudiantes, los docentes han debido implementar metodologías de aprendizaje activo con uso de las TIC. Este fue el caso de los profesores que imparten “Química en Contexto” a estudiantes de ingeniería. El año 2013 decidieron hacer una transformación de la asignatura, implementando Flipped Classroom para el trabajo en aula e indagación guiada para el trabajo de laboratorio. Este artículo explica cómo fue implementada la transformación y presenta un análisis comparado de los resultados, en el que se contrasta el desempeño de los estudiantes (basado en notas) en los períodos anterior y posterior. Con la transformación, la tasa de aprobación se duplicó y la tasa de deserción disminuyó sistemáticamente desde un 40% (en 2014) a un 17% (en 2017). En general, hubo una mejora de los resultados en los diferentes tipos de evaluaciones. La mejora más importante se observó en el trabajo de laboratorio, aun cuando el nivel de exigencia fue mayor, lo que se atribuyó a los siguientes hechos: (i) con la metodología indagación guiada, los estudiantes construyeron sus propios aprendizajes; (ii) la nota de laboratorio tuvo mayor peso en la nota final; y (iii) los estudiantes no tenían la posibilidad de no hacer, pues esto implicaba reprobación inmediata. Se constató que una implementación exitosa de Flipped Classroom depende de que el estudiante dé una máxima valoración al trabajo autónomo y actúe en consecuencia

Developing core sets for persons following amputation based on the International Classification of Functioning, Disability and Health as a way to specify functioning

Amputation is a common late stage sequel of peripheral vascular disease and diabetes or a sequel of accidental trauma, civil unrest and landmines. The functional impairments affect many facets of life including but not limited to: Mobility; activities of daily living; body image and sexuality. Classification, measurement and comparison of the consequences of amputations has been impeded by the limited availability of internationally, multiculturally standardized instruments in the amputee setting. The introduction of the International Classification of Functioning, Disability and Health (ICF) by the World Health Assembly in May 2001 provides a globally accepted framework and classification system to describe, assess and compare function and disability. In order to facilitate the use of the ICF in everyday clinical practice and research, ICF core sets have been developed that focus on specific aspects of function typically associated with a particular disability. The objective of this paper is to outline the development process for the ICF core sets for persons following amputation. The ICF core sets are designed to translate the benefits of the ICF into clinical routine. The ICF core sets will be defined at a Consensus conference which will integrate evidence from preparatory studies, namely: (a) a systematic literature review regarding the outcome measures of clinical trails and observational studies, (b) semi-structured patient interviews, (c) international experts participating in an internet-based survey, and (d) cross-sectional, multi-center studies for clinical applicability. To validate the ICF core sets field-testing will follow. Invitation for participation: The development of ICF Core Sets is an inclusive and open process. Anyone who wishes to actively participate in this process is invited to do so