Exposicion economica al tipo de cambio de las sociedades anonimas chilenas

68 p.Las empresas chilenas, en este caso las sociedades anónimas abiertas, independientes de si tienen o no operaciones de comercio exterior tienen de una u otra forma dependencia de las variaciones en el tipo de cambio. Sin embargo existe una limitada gama de estudios relativos al tema en el ámbito local, y la evidencia disponible proviene en su mayoría de economías desarrolladas. En un reciente estudio, Chen et al. (2004) encuentra para Nueva Zelanda, economía pequeña y abierta, evidencia que indicaría que para este país los movimientos del tipo de cambio afectan el valor de las empresas transadas en bolsa. Basándose en la similitud con la economía Neo Zelandesa, nace la inquietud de replicar ese estudio en Chile. Esta investigación se justifica en el hecho de que a entender del autor no existen estudios relacionados con el tema en Chile, siendo relevante por al menos dos razones: la alta volatilidad que ha presentado el tipo de cambio desde que se adoptó la paridad flotante a mediados del año 1999 (ver apéndice 1) y por el poco desarrollo del mercado de instrumentos de cobertura. El propósito fundamental de esta memoria es determinar el nivel de exposición de las sociedades anónimas chilenas a variaciones en el tipo de cambio, y analizar algunos factores potenciales que influyen en la magnitud de esta exposición. Bajo la hipótesis de los mercados eficientes, el efecto del tipo de cambio debería ser reflejado en el precio de acciones. Las empresas que cumplen con los criterios de selección son 105, de las cuales alrededor del 40% presenta un nivel significativo de exposición al riesgo de cambio. El grado de exposición de las empresas en forma global es de carácter inverso, es decir, a medida que aumenta el valor del tipo de cambio, el valor de las empresas disminuye. Cabe destacar que la significancia económica es importante, esto se grafica en los montos que las empresas ganan o pierden de su capitalización bursátil ante una variación del dólar. A modo de ejemplo, la empresa menos afectada perdería aproximadamente 351 millones de pesos ante la subida de un 1% del valor de la divisa

VO2 indirect maximum and fitness age of sedentary and non-sedentary

El objetivo es: comparar la edad cronológica con la edad fitness obtenida por medio del VO2 máximo indirecto, de un grupo de personas sedentarias y no sedentarias. Método: 253 personas fueron evaluadas respecto a masa corporal, estatura, perímetro de cintura, frecuencia cardiaca basal y un cuestionario del modelo web "Fitness Calculator". Los resultados demostraron diferencias significativas en las variables antropométricas y fisiológicas entre personas sedentarias y no sedentarias (P<,001). Las personas no sedentarias tienen un mayor VO2máx en comparación con las personas sedentarias. Las personas sedentarias indican que presentan una edad fitness que se encuentra sobre 12 años cronológicos promedio de lo esperado. Conclusión: Las personas sedentarias tienen una mayor edad fitness, esto permite establecer que su cuerpo se deteriora más rápido que los no sedentarios. El bajo VO2 máx es un potente predictor de la capacidad cardiorrespiratoria y se establece como un predictor de enfermedades cardiovascularesThe purpose was to compare chronological age with fitness age obtained through indirect VO2max in a group of sedentary and non-sedentary people. Method: 253 people were evaluated for body mass, height, waist circumference, basal heart rate and a web model questionnaire "Fitness Calculator". The results: showed significant differences in anthropometric and physiological variables between sedentary and non-sedentary people (P <.001). Non- Sedentary people have a greater higher VO2máx group compared to sedentary people. This indicates that sedentary people have a fitness age 12 years over their expected chronological average age. Conclusion: Sedentary people have a higher fitness age; therefore your body deteriorates faster than the nonsedentary people. A low level of VO2máx is a powerful predictor of cardiorespiratory capacity and of cardiovascular diseasesEl estudio fue financiado por la Escuela de Kinesiología de la Universidad Bernardo O`higgin

Cyrhetrenylaniline and new organometallic phenylimines derived from 4- and 5-nitrothiophene: Synthesis, characterization, X-Ray structures, electrochemistry and in vitro anti-T. brucei activity

A novel series of cyrhetrenyl (3a-4a) and ferrocenyl (3b-4b) Schiff bases were synthesized through a condensation reaction, between the known 4-ferrocenylaniline (2b) or the unreported 4-cyhretrenylaniline (2a) with 4- or 5-nitrothiophenecarboxaldehyde. The structure of 2a and the new Schiff bases have been elucidated using conventional spectroscopic techniques (FT-IR, 1H and 13C NMR), mass spectrometry, and single-crystal X-ray diffraction analysis of compounds 2a, 4a and 3b. Cyclic voltammetry of organometallic phenylimines derived from 5-nitrothiophene showed NO2 group reduction potentials (E1/2z 0.575 V) that were more anodic than those registered for their 4-nitro analogues (E1/2z 0.981 V). All organometallic imines were tested against the bloodstream form of Trypanosoma brucei. Evaluation indicated that the most active complexes are the 5-nitrothiophene derivatives, 4a, which were remarkably more active than nifurtimox. In addition, complex 4b resulted in less toxicity to host L6 cells than nifurtimox. The results revealed that the electronic effects of cyrhetrene and ferrocene are not an influential factor in E1/2 and anti-Trypanosoma brucei activity for these new imines, which is probably due to the non-coplanarity of the [(h5-C5H4)-C6H4-N=CH-(C4H2S)] system

Correlation effects in ionic crystals: I. The cohesive energy of MgO

High-level quantum-chemical calculations, using the coupled-cluster approach and extended one-particle basis sets, have been performed for (Mg2+)n (O2-)m clusters embedded in a Madelung potential. The results of these calculations are used for setting up an incremental expansion for the correlation energy of bulk MgO. This way, 96% of the experimental cohesive energy of the MgO crystal is recovered. It is shown that only 60% of the correlation contribution to the cohesive energy is of intra-ionic origin, the remaining part being caused by van der Waals-like inter-ionic excitations.Comment: LaTeX, 20 pages, no figure

Ecohydrology and ecosystem services of a natural and an artificial bofedal wetland in the central Andes

High-altitude wetlands of the Central Andes, locally known as bofedales, provide important ecosystem services, particularly carbon storage, forage provisioning, and water regulation. Local communities have artificially expanded bofedales by irrigating surrounding grasslands to maximise areas for alpaca grazing. Despite their importance, biophysical processes of both natural and artificial bofedales are still poorly studied, which hinders the development of adequate management and conservation strategies. We analyse and compare the vegetation composition, hydrological variables, groundwater chemistry, and soil characteristics of a natural and an artificial bofedal of at least 10 years old in southern Peru, to understand their interrelations and the consequences for ecosystem service provisioning. We do not find statistically significant differences in the soil, water, and vegetation characteristics. Soil organic carbon (SOC) content, which we use as a proxy for carbon storage, is negatively correlated to dissolved oxygen, pH, and soil water temperature. In addition, Non-Metric Multidimensional Scaling analysis shows a positive relation between plant community composition, SOC content, and water electric conductivity. Our results suggest a three-way interaction between hydrological, soil, and vegetation characteristics in the natural bofedal, which also holds for the artificial bofedal. Vegetation cover of two of the most highly nutritious species for alpaca, Lachemilla diplophylla and Lilaeopsis macloviana with 19-22% of crude protein, are weakly or not correlated to environmental variables, suggesting grazing might be obscuring these potential relationships. Given the high economic importance of alpaca breeding for local communities, expanding bofedales artificially appears an effective strategy to enhance their ecosystem services with minimal impact on the ecohydrological properties of bofedales

Enteric infection with an obligate intracellular parasite, Encephalitozoon cuniculi, in an experimental model.

Rabbits were intrarectally infected with 3 doses (5 x 10(3), 5 x 10(5), and 5 x 10(7] of an obligate intracellular parasite, Encephalitozoon cuniculi, with or without prior colonic lavages. Although chronic administration of enemas seems to interfere to some degree with the intestinal translocation of the parasite, systemic infection was observed in both manipulated and nonmanipulated animals. The animals responded with antibodies of immunoglobulin A (IgA) and IgG isotypes, reflecting the route of infection. They also produced significant amounts of circulating immune complexes composed of IgA and IgG antibodies and E. cuniculi antigens. Lesions compatible with encephalitozoonosis were seen in the liver, kidney, lung, and brain. In all instances, nonmanipulated animals had more severe lesions than manipulated rabbits given the same dose of parasites. Levels of serum antibodies, circulating immune complexes, and histopathologic changes were associated with the infection dose. The presented data suggest that human microsporidiosis may also be transmitted via the rectal route. It is, therefore, of clinical relevance in view of several reports of microsporidian infections in patients with acquired immunodeficiency

Ab initio many-body calculations on infinite carbon and boron-nitrogen chains

In this paper we report first-principles calculations on the ground-state electronic structure of two infinite one-dimensional systems: (a) a chain of carbon atoms and (b) a chain of alternating boron and nitrogen atoms. Meanfield results were obtained using the restricted Hartree-Fock approach, while the many-body effects were taken into account by second-order M{\o}ller-Plesset perturbation theory and the coupled-cluster approach. The calculations were performed using 6-31$G^{**}$ basis sets, including the d-type polarization functions. Both at the Hartree-Fock (HF) and the correlated levels we find that the infinite carbon chain exhibits bond alternation with alternating single and triple bonds, while the boron-nitrogen chain exhibits equidistant bonds. In addition, we also performed density-functional-theory-based local density approximation (LDA) calculations on the infinite carbon chain using the same basis set. Our LDA results, in contradiction to our HF and correlated results, predict a very small bond alternation. Based upon our LDA results for the carbon chain, which are in agreement with an earlier LDA calculation calculation [ E.J. Bylaska, J.H. Weare, and R. Kawai, Phys. Rev. B 58, R7488 (1998).], we conclude that the LDA significantly underestimates Peierls distortion. This emphasizes that the inclusion of many-particle effects is very important for the correct description of Peierls distortion in one-dimensional systems.Comment: 3 figures (included). To appear in Phys. Rev.

GC Insights: Lessons from participatory water quality research in the upper Santa River basin, Peru

Here we share four key lessons from an inter-disciplinary project (Nuestro Rio) that gathered community perspectives on local water quality in the Santa River basin (Peru) utilising a digital technological approach where we collected data via a novel photo elicitation app, supported by a field work campaign. The lessons explored in this article provide insights into challenges and opportunities for researchers considering developing technological tools for encouraging participation and engagement in marginalised communities