vgaraujov/thesis-chile huggingface dataset:
Ecological aspects of thermoregulation at high altitudes: the case of andean Liolaemus lizards in northern Chile

We document activity field temperatures, daily activity patterns, and extent of thermoregulation in four species of Liolaemus lizards inhabiting at high altitude (above 3500 m) in the Andes of northern Chile. These four species have similar activity field temperature (Tb near 29 C) despite their being distributed at different altitudinal belts. However, conspicuous differences exist between higher-altitude (L. alticolor and L. jamesi) and lower-altitude (L. islugensis and L. ornatus) lizards regarding extent of thermoregulation and activity period. Some differences in morphology, behavior, and patterns of microhabitat occupancy are also apparent among these four species and are seemingly related to the thermal environment to which they are subjected. In comparison to eight low-altitude Liolaemus species in central Chile (Tb near 35 C) the four high-altitude species in northern Chile have lower activity field temperature. The latter is apparently due to the constraints imposed by the harsh Andean thermal environment, a hypothesis supported by the fact that high-altitude Liolaemus lizards under laboratory conditions demonstrate body temperatures that exceed by 5 C or more, those recorded in the field.
Thermogravimetric analysis of polycarbonates and polythiocarbonates with chlorinated aromatic side-rings

The thermal stability and kinetics parameters of polycarbonates and polythiocarbonates derived from diphenols with chlorinated aromatic side-rings were studied. The polycarbonates exhibited a higher thermal stability than the polythiocarbonates, except for polythiocarbonate Ib, which displayed similar behaviour to that of the analogous polycarbonate. The kinetic parameters of the thermal decomposition were determined by using the Arrhenius relationship and a computer program. In the considered temperature range, all the polymers degraded in a single stage with first-order kinetics.
Catalytic activity and visible spectroscopy of [Rh(norbornadiene)Cl]2/p-RC6H4)3P system in methanol

The catalytic hydrogenation of hex-1-ene in methanolic solution with [Rh(norbornadiene)Cl]2/(p-RC6H4)3 P (R=H, Me or OMe) systems preparedin situ has been measured. The catalytic activity shows a dependence on the ageing of the catalyst precursor solution in the presence of air. A spectroscopic study (visible region) has been carried out for the system with triphenyl phosphine and shows degradation with the formation of [Rh(norbornadiene)PPh3Cl] as an intermediate. It was demonstrated that the spectral changes and the consequent catalytic activity are due to PPh3 loss because of the oxygen dissolved in the media.
Polymer conformation and viscometric behaviour:1. conformational transition in poly (benzyl methacrylate) in dilute solutions

The viscometric and refractometric behaviour of poly (benzyl methacrylate) (PBM) in isobutyl methyl ketone (IMK) as a function of the temperature was studied. The viscometric relations in IMK and toluene by membrane osmometry and GPC at 25ºC were established. The viscometric results show discontinuities in the intrinsic viscosity [?] in IMK and sharp changes in the conformational and thermodynamic parameters K? and B. The variation on the unperturbed dimensions of the polymer chain was attributed to a conformational transition. The influence of the side groups was analyzed. The conformational behaviour of this polymer was compared with the saturated corresponding poly (cyclohexyl methyl methacrylate).
Diolefin rhodium(I) complexes with tropolone and related ligands

Rhodium(I) tropolonate and salicylaldehydate complexes of the general formula Rh(A)(diolefin) (A = tropolonate, ?-iso-propyltropolonate, ?-methyltropolonate and salicylaldehydate; diolefin = 1,5-cyclooctadiene, 2,5-norbornadiene and tetrafluorobenzobarrelene) have been prepared by several routes. The ability of Rh(trop)(COD) to function as an intermediate for the synthesis of other neutral and cationic rhodium(I) complexes has been studied and its hydroformylation activity has been explored briefly.
Motor innervation of the bursalis muscle (nictitating membrane) in the lizard Callopistes maculatus

The motor neurones which innervate the bursalis muscle of the lizard Callopistes maculatus were identified by means of intra-axonal retrograde transport of horseradish peroxidase. These neurones were distributed in the oculomotor abducens and accessory abducens nuclei. In the oculomotor nucleus one group of neurones was located in the ventral subnucleus of the contralateral side while the other group was found in the dorsolateral subnucleus of the ipsilateral side. In the abducens and accessory abducens nuclei all the neurones were in the ipsilateral side. The accessory abducens cells, although less numerous, were larger and had a prominent dendritic field in close relationship with the nucleus descendens nervi trigemini.
Seasonality of conception in human populations in Chile

Seasonality of conceptions in human populations in Chile was studied for a period of 30 years (1945 1974). Clear seasonal conception courses exist in the country, exception made of the northern and southern extremes. Seasonal flux is concentrated mainly in January, but also secondary increases in April and June were observed. Along the 30-year period a general pattern of decreasing seasonality is observed. Conception is significantly related to temperature and photoperiod in this country, the maximum rates of conceptions being observed in coincidence with the maximum temperatures and photoperiods. Nonclimatic factors which may be affecting seasonality of conceptions are also discussed.
Polymer conformation and viscometric behaviour: 6. Synthesis, characterization and chain flexibility of (phenyl methacrylate-co-menthyl methacrylate) copolymers

Phenyl methacrylate-co-Menthyl methacrylate copolymers of different compositions were synthetized by radical polymerization in benzene at 298°K. Copolymers from three different compositions were fractionated by solubility. Number average molecular weights ¯Mn were obtained by osmometric measurements. The Mark-Houwink-Sakurada (MHS) equations were established in benzene at 298°K and the unperturbed dimensions determined by using the Stockmayer-Fixman extrapolation. From these results, the rigidity parameter σ was determined. The results show that the rigidity of the copolymers increase when the menthyl methacrylate content increase, and this is discussed in terms of specific interactions between the different units of the chain. The influence of the nature of the side group and their steric hindrance to rotation is also discussed.
Autoimmune thyroid disease in the puerperium. Predictive value of thyroid enlargement and related hormonal changes occurring during pregnancy

The incidence of goiter detected during pregnancy and its significance as an indicator of autoimmune thyroid disease after delivery was investigated in a sample of 707 pregnant women (81% in their 2ndtrimester of gestation). Goiter was detected in 106 subjects (15%). Blood T4, T3, TSH, free T4 index (FT4I), antimicrosomal antibodies (AMA) and urinary iodine excretion were measured in these women and in a control group of gravidas without goiter. These measurements were repeated at 1 and 3 months after delivery. Compared with controls during pregnancy, subjects with goiter had lower FT4I values (11.0 2.8 vs 9.0 1.8; p < 0.01) and higher TSH values (2.9 0.6 ?U/ml vs 4.2 2.1 ?U/ml; p < 0.01). In contrast, T4, T3, AMA and urinary iodine excretion values were similar in both groups. In subjects with goiter FT4I values increased over pregnancy levels at 1 month (11.2 2.0; p < 0.05) and 3 months (14.0 3.0; p < 0.05) after delivery; in 29% a biochemical hyperthyroidism (FT4I > 13.5) was detected. During the same period TSH values decreased significantly (1 month: 1.9 0.7 ?U/ml; p < 0.05; 3 months: 2.7 3.0 ?U/ml; p < 0.05). Frequency of positive AMA increased from 8.6% during pregnancy up to 32.1% in the post-delivery period (p < 0.01). In the control group no variation in the FT4I, TSH or AMA were observed after delivery. These results indicate that goiter during pregnancy is common in Chilean gravidas and that it has predictive value for the appearance of autoimmune thyroid disease after delivery.
Improved description of the small-x limit of deep inelastic scattering

In this paper we attempt to find, within the framework of perturbative QCD, an improved description of the small-x region of deep-inelastic scattering. Motivated by results on the Pomeron in QCD, we investigate diagrams with a system of an arbitrary number of ghion lines in thet-channel. The gluon lines are allowed to interact pairwise in all possible combinations. We find that the leading behaviour of these diagrams comes from configurations where the gluon lines arrange themselves into non interacting, non-forward ladders. We then analyse couplings between gluon ladders, in particular non-planar ones. We compare our results with a previous study of Gribov, Levin, and Ryskin. In agreement, with them we conclude that the sum of these diagrams leads to a tempered increase of the structure function in the small-x region.
Vegetation change in large clearings: Patterns in the Chilean matorral

Previous studies have shown that in Chile the so called mature matorral can have the form of either a continuous matrix of shrubs (wet sites) or of multispecific clumps of shrubs (dry sites). After clearing, sites are known to be initially covered by annuals and then byBaccharis spp. orAcacia caven shrubs. Further vegetation changes are still not documented. In the first part of this contribution we show evidence indicating that the ?seed rain? of plants dispersed by birds is important only around bird perches and that in general ?seed shadows? of mature matorral shrubs are small. These results suggest that late recolonization of cleared areas occurs by a slow diffusion process in which the presence of perching sites for birds plays a significant role. Then we exhibit results regarding the importance of seasonal droughts and European rabbits in explaining transitions between the various types of plant cover. Here we conclude that nursing by older shrubs and not by rocks or fallen branches, is a requirement to insure the survival of seedlings belonging to mature matorral shrubs. Nurses are important regarding both summer desiccation and herbivory. These nurse effects seem to be more important at dry sites where rabbits are also more numerous, than at wet sites where conditions seem somewhat milder and vegetation change could be faster. In the last part we discuss a scheme of vegetation change that incorporates these processes and explains the relation between them, the vegetation types and the recolonization of wet and dry areas. Finally, a brief mention is made to the difference between these processes and the comparable ones in the California chaparral.
Plants intruding Laretia acaulis (Umbelliferae) a high Andean cushion plant Vegetatio

Several plants invade the cushions of Laretia acaulis in the high Andean communities of central Chile. Humus develops among the rosettes, and 42 different species settle on the cushions. Most of these species are also found outside the cushions. Semi-woody chamaephytes, hemicryptophytes and cryptophytes have a similar cover on both substrates, while the cover of woody chamaephytes and therophytes is smaller on the cushions. The diversity and cover of invading plants, which vary with altitude, result from interactions among the environmental conditions, cushion morphology and the surrounding vegetation.
Seasonality of mortality in human populations of Chile as related to a climatic gradient

Mortality of human populations in Chile was studied from a latitudinal and seasonal perspective, and related to climate and main diseases. Approximately 3 mill. deaths were analyzed. Seasonality considered along a latitudinal and climatic gradient is almost absent in the northern portion of the country, in the central part peaks are evident in summer, at latitudes 40 S in winter and at 45 S in winter and spring. Seasonality along the years of analysis shows a different behaviour for the different zones of the country and no unique pattern is evident. A clear relationship between the air enthalpy and seasonality of mortality is detected. Circulatory diseases appear as the most important causes of deaths, exception made of latitude 40 where respiratory diseases are the significant causes of deaths. Age groups below one and above 65 years are mostly affected.
Ligninases fromChrysonilia sitophila (TFB-27441 strain)

Ligninase found in the extracellular medium of cultures ofChrysonilia sitophila was purifieded by ion exchange chromatography. Sodium dodecylsulfate/polyacrylamide gel electrophoresis allowed the determination of 68,000, 48,300, and 48,000 daltons for the molecular weights of ligninase I, II, and III, respectively. The absorption spectrum of the enzymes indicated the presence of a heme prosthetic group. The absorption maximum of the native enzyme II at 400 nm decreased in the presence of one equivalent of hydrogen peroxide. With an additional equivalent of phenol the maximum at 400 nm shifted to 417 nm. This spectrum is similar to horseradish peroxidase compound II. The pyridine hemochromogen absorption spectrum and iron content indicated that ligninases I, II, and III contained a Fe/heme ratio values of 0.8, 1.3, and 1.2 by a molecule of protein, respectively. These enzymes oxidize lignin efficiently, followed by the fluorescence technique and by the photon emission method.
Somatic embryogenesis from cell suspension cultures in Carica candamarcensis

Cell suspension cultures of Carica candamarcensis derived from hypocotyl calli were tested concerning their in vitro embryogenic capacity to improve asexual propagation rates in this species. Somatic embryos developed in culture from cells in suspension or from microcalli. Responses were affected by nutrient media and phytohormones used. Best results were obtained by growing the cells in suspension in Nitsch and Nitsch medium containing naphthaleneacetic acid and then plating them upon the same medium containing benzyladenine, or combinations of both hormones.
Food preferences by Octodon degus (Rodentia caviomorpha): Their role in the chilean matorral composition

The food preferences of Octodon degus are examined in laboratory test. Results indicate that degus prefer new rather than mature leaves of Chilean matorral shrubs, and that degus do not discriminate between new leaves (equivalents of shrub seedlings) of different shrub species. The significance of degus preferences in relation to matorral composition is discussed.
Preparation and properties of cationic trimethylphosphiterhodium(I) complexes with arene ligands

The preparation and properties of cationic arenerhodium(I) complexes of general formula [Rh {P(OMe)3}(?6-arene)]A [arene=C6H6?nMen (n=0, 1, 2, 3, 4 or 6); A=ClO 6? , PF 6? ] are described. The coordinated arene is dissociated in (CD3)2 CO or DCCl3 solution and this dissociation decreases with increased methyl substitution of the arene ligand. The ability of these cationic complexes to function as an intermediate for the synthesis of other rhodium(I) complexes by displacement of the coordinated arene with ? or ?-donor ligands has been studied.The preparation and properties of cationic arenerhodium(I) complexes of general formula [Rh {P(OMe)3}(?6-arene)]A [arene=C6H6?nMen (n=0, 1, 2, 3, 4 or 6); A=ClO 6? , PF 6? ] are described. The coordinated arene is dissociated in (CD3)2 CO or DCCl3 solution and this dissociation decreases with increased methyl substitution of the arene ligand. The ability of these cationic complexes to function as an intermediate for the synthesis of other rhodium(I) complexes by displacement of the coordinated arene with ? or ?-donor ligands has been studied.
Synthesis and reactivity of cationic trimethyltetrafluorobenzobarrelene rhodium(I) complexes

The preparation and properties of cationic rhodium(I) complexes of the types [Rh(Me3TFB)L2]PF6 (L=O. N. P, As or Sb-donor ligands, Me3TFB=trimethyltetrafluorobarrelene), [Rh(Me3TFB) (?6-arene)]PF6 (arene=C6Me6, C6H6Me3, C6H6 or C10H8) and [Rh(Me23TFB)(PPh3)L]PF6 (L=Me2CO or Me2SO) are described. Some complexes react with carbon monoxide at normal pressure with displacement of Me3TFB and formation of carbonyl derivatives. The arene-exchange behaviour for the new complex with naphthalene (C10H8) was examined in acetone solutions.
Effect ofStreptomyces viridosporus T7A on kraft lignin

The ability of the lignino-cellulolytic actinomyceteStreptomyces viridosporus T7A to attack purified fractions of kraft lignin was examined. In the presence of 0.3% yeast extract, high-molecular weight kraft lignin (MW>3000, ether-insoluble fraction) does not affect growth of this microorganism significantly, whereas low-molecular weight kraft lignin (MW<3000, ether-soluble fraction) inhibits its development. Accordingly, average molecular weight of the ether-insoluble fraction after bacterial growth remained unaltered, as measured by Sephadex G-50 gel permeation chromatography. Slight modifications were detected by high performance liquid chromatography in the ether-soluble fraction after incubation with the microorganism.S. viridosporus T7A partially decolorized Remazol Brilliant Blue R during growth on wheat lignocellulose. However, decolorization of either fraction of kraft lignin was not observed. These results suggest that the filamentous bacteriumS. viridosporus T7A is not suitable for pulp mill effluent treatment.
Patterns of interhemispheric and striate-peristriate connections in visual cortex of the South American marsupial Marmosa elegans (mouse opossum)

We have analyzed the distributions of inter-hemispheric and striate-peristriate connections in the South American marsupial, Marmosa elegans (mouse opossum). Following multiple injections of horseradish peroxidase (HRP) into one hemisphere, we found that anterogradely labeled terminations and retrogradely labeled perikarya are distributed unevenly in the contralateral hemisphere, forming a distinct tangential pattern in striate and peristriate cortex. This pattern delineates as many as eight peristriate areas relatively poor in commissural connections in lateral peristriate cortex, and in lateral and anterolateral portions of peristriate cortex. Single injections of HRP conjugated with wheat germ agglutinin into anterior or posterior regions of striate cortex produced as many as nine discrete ipsilateral fields of labeled perikarya, and terminations distributed over a broad cortical area in lateral and anterolateral peristriate cortex. Our observations of multiple areas with little or no HRP labeling in the interhemisferic pattern, and of multiple ipsilateral striate projection fields, indicate that the topography of visual cortex in Marmosa is highly elaborate, and suggest that extrastriate cortex is subdivided into several visual areas. Furthermore, by showing that the organization of visual cortex in this marsupial is as complex as in many placental mammals, our data support the view that a basic cortical plan, consisting of multiple visual areas, appeared early in mammalian evolution.
Oxytalan fibres in the epidermal basement membrane of Lineus atrocaeruleus (Nemertia)

The basement membrane of the epidermis in Lineus atrocaeruleus(Schmarda 1859) (Nemertia: Heteronemertea) is formed by a tight network of oxytalan fibres which send projections into the epidermis and branch towards the proximal dermis, in close association with the subepidermal musculature. The histophysiology of this relationship is discussed.
Hydrogen transfer reactions catalyzed by neutral rhodium(I) Schiff base complexes

Hydrogen transfer reactions from 2-propanol to acetophenone or cyclohexene are catalyzed by neutral rhodium(I) complexes of the type [Rh(COD)L] and [Rh2(COD)2L'] (where L and L' are Schiff base ligands and COD=cycloocta-1,5-diene). Some dependency of the catalytic activity on the electronic and steric properties of the ligands are discussed.
Landscape change under indirect effects of human use: the Savanna of Central Chile

The Chilean Intermediate Depression to the north of Santiago has experienced a physiognomical transformation from a Prosopis chilensis woodland to an Acacia caven savanna. Today P. chilensis trees are scarce and belong mostly to the larger size classes. By contrast A. caven seems to reproduce frequently and its populations consist of individuals of all size classes. In this paper we document these changes and report the results of tests aimed at determining the causes of these physiognomical changes. We found that livestock, leporids, introduced Mediterranean forbs and agriculture account for differences in seed dispersal and survival of A. caven and P. chilensis, which can explain the documented changes in the Chilean landscape.
Variation and persistence of the middle rocky intertidal community of central Chile with and without human harvesting

Humans are an important intertidal predator in central Chile. Following a five-year study we report on the effects of the exclusion of humans from the rocky intertidal at Las Cruces, central Chile. The middle intertidal of harvested and non-harvested areas diverged in species diversity and composition during the experiment. In harvested areas the middle intertidal rocky shore was dominated throughout the study by a monoculture of mussels, Perumytilus purpuratus. When humans were excluded, the middle intertidal community switched to one dominated by barnacles (predominantly Jehlius cirratus and Chthamalus scabrosus); this community has persisted for at least three years, despite the presence of forces e.g. mussel larvae, that have the potential to alter the community structure. Such changes were mediated by the muricid gastropod Concholepas concholepas, a key-stone predator. As a consequence of the above changes, the species diversity, H', (primary space occupiers) in the non-harvested area increased from H'=0 at the beginning of the study in 1983 (when the middle intertidal community was dominated by mussels), to values ca H'=2 toward the middle of the study in 1984 (which coincided with the maximum predatory impact of C. concholepas) and subsequently decreasing to ca H'=0.5 at the end of the study in 1987 (when the middle intertida community was dominated by barnacles).
Science in Latin America how much and along what lines?

Scientific output in the Caribbean and Latin American countries was studied examining the publications indexed by the Institute for Scientific Information which conform the mainstream literature. The growth patterns of first-authors-publishing-scientific-papers coming from the five most productive countries of the region were determined. In addition, the scientific publications from each country of the region, as indexed in 1981, were classified per field. It was found that most of the research was done in the life sciences area. However, the small scientific output observed in all fields appears insufficient to assure a positive role of science for the best overall development of each individual society. This situation may reflect a lack of support for the progress of science in these countries and therefore political commitment towards this purpose is considered to be of particular importance.
Interpretations into monadic algebras

In [3], O. C. García and W. Taylor make an in depth study of the lattice of interpretability types of varieties first introduced by W. Neumann [5]. In this lattice several varieties are identified so in order to distinguish them and understand the fine structure of the lattice, we propose the study of the interpretations between them, in particular, how many there are and what these are. We prove, among other things, that there are eight interpretations from the variety of Monadic algebras into itself.