Últimos itens adicionados do Acervo: Universidade Católica de Temuco

A Universidade Católica de Temuco é uma institução privada confessional do Chile, fundada pelo bispo Alejandro Menchaca Lira em 1959.

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‣ Estimation of genetic relationships between Spanish and Creole goat breeds using microsatellite markers

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
We have analyzed three Creole goat populations from Peru, Mexico and Chile using microsatellite markers. We have also analyzed the genetic relationship between them and Murciano-Granadina and Malagueña Spanish goat breeds. The average number of alleles per locus was similar in all populations (7.3) except the Chilean Creole (5.1). This Creole goat population has presented the lowest value of observed (Ho) (0.53) and expected (He) heterozygosis (0.59). The Peruvian Creole has presented the highest values of Ho (0.70) and He (0.71). We have found a scarce level of genetic differentiation between goat populations (FST= 0.069) being more important the individual genetic differences due to crossbreed with several breeds. The Peruvian Creole was closed to analyzed Spanish breeds, followed by Mexican Creole. Finally the Chilean Creole was the most distant to the others populations.

‣ Chromosomes of the limpet Fissurellalimbata (Sowerby, 1835) from Northern Chile (Archaeogastropoda: Fissurellidae)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Fissurella limbata (Sowerby, 1835), presenta un número cromosómico diploide 2n = 32 similar al descrito previamente para otras especies del género Fissurella Reeve 1849. El juego cromosómico haploide deF limbata tiene siete cromosomas metacéntricos, seis submetacéntricos y tres subtelocéntricos. Los cromosomas son pequeños y no exceden de 4,0 mm en longitud.

‣ On the settling of a bidisperse suspension with particles having different sizes and densities

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The settling of a bidisperse suspension with small particles having different sizes and densities can be described by an initial value problem for a system of two non-linear, first-order conservation laws. Solutions to this problem are in general discontinuous and exhibit kinematic shocks that separate areas of different composition. The solution requires the construction of so-called elementary curves in phase space, which are determined from eigenvector fields of the Jacobian of the flux function. Differences in solution behavior to the previously analyzed equal-density case are due to an umbilic point, which appears for different densities only. The initial value problem is eventually solved by the front tracking method, which generates a series of Riemann problems. It turns out that the solution of the problem predicts a fairly complex process of sediment formation, and that the stationary solution can consist of non-constant smooth transitions. This observation is of interest for manufacturing of functionally graded materials.

‣ The use of null models to explain crustacean zooplankton associations in shallow water bodies of the Magellan region, Chile

Fonte: Crustacean Society Publicador: Crustacean Society
Tipo: Artículo de Revista
Português
Southern Patagonia is characterized by the presence of numerous shallow ponds with variable trophic and conductivity conditions, and a relatively high species richness of Crustacea. In the present study, published information and data collected in field work on shallow ponds in the Magellan region was reviewed and analysed using co-occurrence of null models, with the aim to determine potential random factors as regulators on crustacean zooplankton assemblages, using a presence-absence matrix. The results of C-score analysis revealed the existence of non-random effects mainly in data collected in 1989-1990 for Torres del Paine National Park, and in data on coastal shallow ponds close to Punta Arenas, collected in October 2006. A different situation is reported for shallow ponds located in other zones of the Magellan region, including also some in the Torres del Paine National Park collected in October 2001, and for shallow ponds close to Porvenir on Tierra del Fuego Island, collected in April 2007. The existence of non-random effects was probably due to markedly different zooplankton assemblages, assumed to be caused mainly by the conductivity gradient and trophic level. Random effects can probably be explained by the condition that a few species occur practically at all localities studied...

‣ Branchinecta gaini Daday, 1910 (Branchiopoda, Anostraca) as a bioindicator of oligotrophic and low conductivity shallow ponds in southern Chilean Patagonia

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The south of Patagonia is characterized by its semi-arid weather and numerous small, temporary and permanent shallow ponds. The aquatic crustaceans of these water bodies are characterized by their endemism and species richness. The present study was done in the surroundings of Punta Arenas (53°S, Chile), and included six shallow ponds. Samples for conductivity, total dissolved solids, chlorophyll, and crustacean zooplankton as well as littoral species of crustacea were collected. Our study revealed that Branchinecta gaini Daday, 1910 occurred at low conductivity (0.55 mS/cm), and low total dissolved solids (0.28 g/l) and chlorophyll (2.70 μg/l) concentrations, such compared to sites without fairy shrimp populations, that had significantly high conductivity (3.58 mS/cm), and high total dissolved solids (1.80 mg/l) and chlorophyll (12.80 μg/l) concentrations. The results partially agree with the first descriptions of Patagonian water bodies that indicated the presence of fairy shrimps in low conductivity waters. The observations of the presence of B. gaini and other associated microcrustaceans are similar to descriptions of unpolluted water bodies in Antarctica, and those results would support the observations of the present paper. Other reports on fairy shrimp habitats mentioned a wide range of both salinity and trophic status. Other ecological and biogeographical topics on fairy shrimps are also discussed.

‣ Populations of dwarf araucaria (Araucaria araucana) in the Nahuelbuta coastal range, Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Araucaria araucana (araucaria or pehuén) can normally reach > 20 m in height in most sites where it grows. However, two dwarf populations of A. Araucana were found at the top of the Nahuelbuta coastal range. This study had the goal of characterizing the structure, composition, ages and chemical and physical soil properties of both populations. These populations are dominated by A. araucana, with Nothofagus dombeyi as the main associated species. Dwarfism, is clear in both species. Individuals of A, araucana rarely exceeded 10 m. in height with a high diameter/height relationship compared with similarly-aged normal trees. The diameter annual growth is lower than 0.12 cm. for trees 300 years in age and basal diameters of 36 cm. The presence of short stems and extended and fine branches, like spider legs, confirms the dwarf features of the A. araucana trees. In N. dombeyi 36 to 37 years in age the diameter annual growth is between. 0.26 and 0.27 cm, where most individuals (60-75%) present basal diameters lower than. 15 cm and heights between 1 and 6.5 m. The location of these populations at the top of the Nahuelbuta coastal range over 1,000 m and openly exposed to the Pacific ocean, results from extreme weather conditions that combined with poor and thin soils determine the low tree growth...

‣ A hybrid ARIMA and artificial neural networks model to forecast particulate matter in urban areas: The case of Temuco, Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Air quality time series consists of complex linear and non-linear patterns and are difficult to forecast. Box-Jenkins Time Series (ARIMA) and multilinear regression (MLR) models have been applied to air quality forecasting in urban areas, but they have limited accuracy owing to their inability to predict extreme events. Artificial neural networks (ANN) can recognize non-linear patterns that include extremes. A novel hybrid model combining ARIMA and ANN to improve forecast accuracy for an area with limited air quality and meteorological data was applied to Temuco, Chile, where residential wood burning is a major pollution source during cold winters, using surface meteorological and PM10 measurements. Experimental results indicated that the hybrid model can be an effective tool to improve the PM10 forecasting accuracy obtained by either of the models used separately, and compared with a deterministic MLR. The hybrid model was able to capture 100% and 80% of alert and pre-emergency episodes, respectively. This approach demonstrates the potential to be applied to air quality forecasting in other cities and countries.

‣ Los colonos y la Escuela en la Araucanía : los inmigrantes europeos y el surgimiento de la educación privada laica y protestante en la región de la Araucanía (1887-1915)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The importance that had the European immigration in the period of the conformation of the regional society not indigenous in the Araucanian region at the end of the 19th century and the beginning of the 20th century demonstrate in a significant way in the educational sphere. Indeed, though demographically the presence of European immigrants was never majority population they played an important role in the emergence and development of private schools, especially Germans, Frenchmen, Swiss and English. Many of these immigrants were Protestants and Anglicans, a fact that undoubtedly affected in the creation of not catholic schools because the Franciscan and Capuchin missionaries had a great control on the educational system. In this article show data originated of an historical anthropological research on the flows of European immigration that supports the previous arguments.; La importancia que tuvo la inmigración europea en el período de la conformación de la sociedad regional no indígena de la Araucanía a fines del siglo XIX y principios del XX se manifiesta de manera significativa en la esfera educativa. En efecto, si bien demográficamente la presencia de inmigrantes europeos nunca fue mayoritaria, sí dejó sus huellas en el importante rol que desempeñaron las comunidades de inmigrantes en el surgimiento y desarrollo de escuelas privadas...

‣ Fairy shrimp (Branchiopoda: Anostraca) of Chile camarón duende (Branchiopoda: Anostraca) en Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Portions of Chile were surveyed for Anostraca. Including the two species of Anemia previously reported from Chile, we found 5 new localities and range extensions for 5 species of Branchinecta. Previous studies on Chilean Anostraca have focused on Artemia, and although Branchinecta was previously reported in Antarctica close to Chilean Air Force installations, and in a few temporal ponds in Southern Patagonia, the species were never determined. Brief habitat descriptions, as well as conservation status, and identification keys are presented and discussed. Additionally, we describe a new species from the Atacama Desert, Branchinecta papillata n. sp.

‣ New obsidian source in the araucania region (south central Chile): Chemical and archaeological context of the black riolitic obsidian from the Nevados de Sollipulli

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Un domo de obsidiana negra de composición riolítica aflora entre otras rocas volcánicas en la latitud 38.97716° sur y longitud 71.63528° oeste, en los Nevados de Sollipulli, al oeste del Volcán Sollipulli y al sur del pueblo de Melipeuco en el centro-sur de Chile. Se encuentran fragmentos trabajados de esta misma obsidiana en la superficie de varios sitios arqueológicos de la zona. Esta obsidiana es distinguible visual y químicamente de la obsidiana translúcida gris-verdosa derivada del Volcán Chaitén situado más al sur en la cadena Andina.; A dome of black rhyolite obsidian outcrops among other volcanic rocks at south latitude 38.97716° and west longitude 71.63528°, within the Nevados de Sollipulli, west of the Sollipulli volcano and south of the town of Melipeuco in south-central Chile. Worked fragments of this same obsidian are found at the surface in a number of archaeological sites in the área. This obsidian is both visually and chemically distinct from translucent grey-green derived from the Chaitén volcano further south in the Andean chain.

‣ Serum concentrations of triiodothyronine, thyroxine and lipid profile in dairy cows fed with a low selenium diet

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The aim of this study was to evaluate the effect of a low Selenium diet and its supplementation on the serum levels of T3, T4 and on the lipid profile in dairy cows under an induced oxidative stress. Twelve pregnant dairy Chilean-Friesian cows were selected and assigned to one of two groups, control (n = 6, Se-D) and treated (n = 6, Se-S) with barium selenate (BaSeO4), both receiving a Selenium-deficient diet (based on a 0.03 ppm Se-content of the DM in the diet before calving, and 0.05 ppm after calving) and oxidized tallow (0.5 kg/cow/day). The Se-S group was supplemented with selenium (1 mg/kg) in the form of BaSeO4 (1 mL/50 kg, s.c.). Prior to the supplementation and every 15 days, heparinized blood and plain blood samples were taken by venous puncture. The blood activity of glutathione peroxidase (GSH-Px, EC 1.15.1.9) was evaluated, also the serum concentrations of T3, T4, total cholesterol, lipoproteins (HDL, LDL and VLDL) and triacylglycerols (TAG). The differences were settled by means of a PROC MIXED of SAS, and the option REPEATED, significance was set at P < 0.05. The Se-supplementation with BaSeO4 did not produce changes in the milk yield (P > 0.05), and the blood activity of GSH-Px was higher in the group Se-S starting 45 days after supplementation (P < 0.05)...

‣ Maintenance of spatial distribution, density and size structure pattern of freshwater mussel Diplodon chilensis gray, 1828 (Bivalvia: Hyriidae) in the Panguipulli Lake, Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The purpose of the present study was to verify eventual changes in spatial distribution, density and size structure in a population of Diplodon chilensis inhabiting sandy and sand-gravel substrates in the Lake Panguipulli after 16 years of studies carried out in the mentioned population. Results indicate that mussels show in 2003 an aggregated spatial distribution in both substrates and a more aggregated distribution in sand - gravel than sandy substrate as in 1987. As in 1987, density was significantly higher in sand - gravel substratum in 2003 (P < 0.01). There were not significantly differences in density within the period elapsed in the same type of substratum. Size structure of population did not show much changes. Nonetheless, young were registered in both substrates in 2003, indicating that recruitment occurred. The results are discussed in relation to the role of these bivalves in the ecosystem and their potential use in ecological evaluation of lacustrine environments.; El propósito del presente estudio fue comprobar si han ocurrido cambios, después de 16 años, en los patrones de abundancia, distribución espacial y estructura de talla de la almeja de agua dulce Diplodon chilensis en sustratos arenosos y areno-pedregosos del sector Chauquén del Lago Panguipulli. Los resultados indican que las almejas en 1987 y 2003 presentan una distribución espacial agregada en ambos sustratos y con una mayor fuerza de la agregación en los sustratos areno-pedregosos que arenosos. La densidad fue significativamente mayor en sustrato areno-pedregoso...

‣ Nuclear DNA content in Galaxias maculatus (Teleostei: Osmeriformes: Galaxiidae)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
El contenido de ADN nuclear (valor 2C) fue determinado en el pez comercial Galaxias maculatus (Galaxiidae) usando microdensitometría de núcleos de eritrocitos sometidos a tinción de Feulgen, utilizando como estándar eritrocitos de trucha arco iris con un valor 2C conocido. El valor 2C de G. maculatus fue 2,21 ± 0,12 pg y su valor C es equivalente a 1,105 pg (1.082,9 pMb). Este valor C está dentro del rango registrado para otras especies de osmeriformes (0,62-3,2 pg). El diámetro promedio de la cabeza del espermatozoide de G. maculatus es menor al promedio descrito para la trucha arco iris utilizado como estándar, lo que coincide con las diferencias observadas en el contenido de ADN nuclear entre ambas especies. Estos datos contribuyen a ampliar los antecedentes genómicos disponibles para G. maculatus y podrían ser útiles en futuros programas tendientes a su manipulación genética.; The nuclear DNA content (2C value) was determined in the commercial fish Galaxias maculatus (Galaxiidae) was determined by microdensitometry of erythrocyte nuclei after Feulgen staining; rainbow trout erythrocytes with a known 2C value were used as a standard. The 2C value of G. maculatus was 2.21 ± 0.12 pg and its C value was equivalent to 1.105 pg (1...

‣ Karyotype study in the surf clam Mesodesma donacium Lamarck, 1818 (Bivalvia: Veneroida: Mesodesmatidae)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Português
Mesodesma donacium is a marine clam distributed from Sechura Bay (5°S) in northern Perú to Chiloé Island (43°S) in southern Chile. Due to the commercial importance of this species, their populations have been reduced in the later years. In this work the karyotype morphology of M. donacium is described for the first time, to be additional to taxonomical, ecological, morphological, and reproductive antecedents previously documented for the species. M. donacium shows a diploid karyotype 2n = 38 with one metacentric, fifteen submetacentric and three subtelocentric chromosome pairs. The total haploid set length was 42.4 μm, and the mean chromosome size was 2.2 μm. M. donacium showed similitude in chromosome number with other species of the Veneroida order, but differences were found in morphology and size of the chromosomes. The cytogenetic relationships between M. donacium and other species of Veneroida is also discussed.; Mesodesma donacium es un almeja distribuida desde Sechura Bay (5°S) en el Norte de Perú hasta la isla de Chiloé (43ºS) en el sur de Chile. Debido a la importancia económica de esta especie, su población ha sido reducida en los últimos años. En este trabajo se describe por primera vez la morfología cariotípica de M. donacium...

‣ Barycentric interpolation and exact integration formulas for the finite volume element method

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
This contribution concerns with the construction of a simple and effective technology for the problem of exact integration of interpolation polynomials arising while discretizing partial differential equations by the finite volume element method on simplicial meshes. It is based on the element-wise representation of the local shape functions through barycentric coordinates (barycentric interpolation) and the introducing of classes of integration formulas for the exact integration of generic monomials of barycentric coordinates over the geometrical shapes defined by a barycentric dual mesh. Numerical examples are presented that illustrate the validity of the technology

‣ Identification of piecewise linear diffusion function in convection-diffusion equation with overspecified boundary

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
In this contribution the identification of a piecewise linear diffusion function in a nonlinear convection-diffusion equation is presented. This inverse problem arises at the parameter identification for a sedimentation- consolidation process of flocculated suspensions in a batch settling experiment. The identification method avoids the minimization of a cost function with the method of least squares. Instead, in each computational time step of the finite difference scheme, the unknown diffusion function is extended by appending a new linear interval to the piecewise linear polygon. The required information is exclusively obtained from an overspecified boundary condition and by employing the discrete solution of the finite difference scheme for the direct problem. The advantage of the proposed approach is its low computational cost

‣ Diet of Lycalopex griseus (Gray, 1837) (Mammalia: Canidae) in the intermediate depression of southern Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
A study about food habits of chilla (Lycalopex griseus) was done in a sector of the intermediate depression of southern Chile, called Predio Rucamanque, Region de la Araucanía. Faeces were collected through three seasons of the year, identifying their diet composition. Results show a trend towards small mammals followed by birds, and in a lesser ratio, insects.

‣ Study on arsenic, mercury, lead and phenanthrene concentration in surf clam (Mesodesma donacium) : Food and toxicological implications

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The coastal environment around the Maipo river outlet in the proximity of San Antonio bay (Vth Region, Chile) it is one of the most contaminated zone of the country due to discharges of industrial wastes on the river that affect the marine environment. The surf clam (Mesodesma donacium, Lamarck 1818) a benthic organism that provides an important source of seafood for human consumption is caught in this area. The total arsenic and mercury, lead and phenanthrene concentrations in the soft body of the surf clam were measured. The concentration of the elements in the marine organism fluctuated between 1,23-1,33 μg/g As, 0,26-0,39 μg/g Hg, and 0,23-0,33 μg/g Pb (dry basis). Phenanthrene was not detected in the samples. In spite of the high concentration of the elements detected in the surf clam, only in the case of Hg their intake could imply a certain grade of risk for human health, especially for young humans. Chronic effects, such as personality changes, neurological damage and others, could exhibit in the medium term. Therefore, it is important to carry out regular food surveillance studies, especially oriented to the specie specific aspect of toxic elements and monitoring of polyaromatic hydrocarbons (PAH) in several marine food.

‣ Body dissatisfaction and body change behaviors in Chile : The role of sociocultural factors

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
With interest in body image and body change behaviors growing around the world, there has been surprisingly little research conducted in Latin America on these issues. In order to gain some understanding of them in this context, this study investigated body image and body change behaviors, and the sociocultural factors that may influence them, among 337 Chilean adolescents aged 12-18 years. Participants completed a questionnaire that assessed BMI, body dissatisfaction, strategies to lose weight and strategies to increase muscle bulk. In addition, perceived pressure from family, peers, and the media to change body shape was evaluated. Results were partially consistent with those reported in Western nations. Girls were found to report greater body dissatisfaction than boys, but no difference was found between males and females in perceived pressure from adults in the family or from older siblings/cousins to lose weight. However, girls experienced higher levels of perceived pressure to lose weight from the media than boys, and boys reported greater perceived pressure from peers to lose weight than girls, and more pressure than girls from all sources to increase muscle bulk. These findings are discussed in relation to research conducted in other contexts...

‣ Cultivation of whitebait (Galaxias maculatus) in Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The growth of commercial aquaculture in Chile generated an income of $2.300 million USD in exports in 2005. Currently, 15 different species are cultivated commercially, of which seven are native; these had returns of 185 million USD. Among these native species is Galaxias maculatus (whitebait), which is endemic to Chile and figures significantly in Chilean fishing statistics. Since the 1990s, the School of Aquaculture of the Universidad Catolica de Temuco has been developing cultivation of this native species. This work presents the state of the art of the cultivation of this fish.