O autorretrato em literatura: ilustração e ruína

A aplicação ao caso literário do termo e do conceito de retrato, aqui incluindo a espécie mais tardia do autorretrato, não é hoje fluente, apesar da reconhecida permeabilidade do género a inúmeras linguagens artísticas e apesar de uma longa tradição de descrições de figura – particularmente no que toca a representação poético-retórica da beleza feminina – que recua à poesia clássica. Partindo de uma possível distinção entre autorretrato literário e variantes várias de escritas intimistas e autobiográficas com as quais delineia fronteiras nem sempre rigorosamente nítidas, é nosso propósito ilustrar, recorrendo a casos selecionados, modos de concretização verbal de autorretrato que se distanciam progressivamente de um paradigma representativo fundado na perceção e na semelhança, aproximando-se ao contrário de registos de rasura, apagamento, ruína, cegueira que questionam uma noção de identidade estabilizável em imagem (visual ou mental), encaminhando o gesto autorrepresentativo para uma meditação sobre a diferença e sobre o irreconhecimento; no limite, para uma condição fora do visível e porventura, arriscando os seus mais básicos pressupostos, para lá da representação.

Groundwater vulnerability and protection in County Tipperary (South Riding), Ireland

The aim of the project was to determine the extent and quality of the groundwater in Tipperary South Riding with a view to developing a groundwater protection plan which would allow the Local Authority to manage, protect and develop the groundwater as efficiently as possible. The geology of the area varies with topography. The low-lying areas of the county comprise mainly Carboniferous limestones while the elevated regions consist of sandstones and shales of Upper Carboniferous, Devonian and Silurian ages. Deformation of these rocks decreases in magnitude moving northwards over the area; the Southern Synclines having suffered the effects of the Hercynian orogeny and the northern region exhibiting Caledonian orogenic trends. Quaternary (subsoil) deposits are found throughout the area and are of variable thickness and permeability. Till is the most widespread deposit with discontinuous pockets of sand and gravel in various proportions, and some marl, alluvium and peat in places. The principal aquifers of the area are the Kiltorcan sandstone formation and various limestone units within the Carboniferous succession. 50 % of south Tipperary constitutes either regionally or locally important aquifers. Secondary permeabilities created by structural deformation, dolomitisation, karstification and weathering processes create high transmissivities and often have large well yields. Specific baseflow analysis highlighted the complexity of the aquifers and proved that the lower part of the Suir river system is a major groundwater resource region. The hydrochemistry and water quality of the local authority groundwater sources was examined briefly. The majority of south Tipperary is underlain by limestone or Quaternary deposits derived from limestone and, consequently, calcium/magnesium bicarbonate waters predominate. The quality of the groundwater in south Tipperary demonstrates that the main concern originates from the presence of E.coli, and Total coliforms. The primary sources of contamination are from farmyard wastes and septic tanks. The vulnerability of groundwater to diffuse and point sources of pollution has been found to be dependent on the overlying soil, subsoil and the thickness of the unsaturated zone. A conceptual rather than quantitative approach is used and it is found that approximately 60% of south Tipperary is designated as being extremely or highly vulnerable. The groundwater protection plan was devised subsequent to an understanding of the aquifer systems, an assessment of the vulnerability, and a review of the Irish planning system and environmental law. It is recommended that the plan be integrated into the county development plan for legislative purposes. A series of acceptability matrices were devised to restrict potentially polluting activities in vulnerable areas while maintaining a balance between protection of the groundwater resource and the need to site essential developments.

Influence of pore size distribution on drying behaviour of porous media by a continuous model

Bundle of capillaries, drying kinetics, continuous model, relative permeability, capillary pressure, control volume method

Um esquema geral para a discussão do movimento de materiais para as células vivas e tecidos

A generalized comprehensive scheme concerning the movement of materials into living cells and tissues is presented. It is designed for use by investigators and teachers who, is assumed, have a previous knowledge of the subject as well as familiarity with previously published literature on the subject. Footnotes to figure 2 X = a constituent component material, arising from extermal sources or through metabolism, capable of migration under favorable conditions. e, i, ec, ic, mc = subscripts indicating location. oC = oxidized cytoplasmic constituents specifically concerned in unidirectional (here invardly directed), diffetial translocation of a particular material X. rC = reduced cytoplasmic constituents specifically concerned. XF = specific free energy (2) of a constituent component in in external or internal phases or in cytoplasm. D = diffusion (4). EA = exchange adsorption (4). MA= metabolic accumulation (4), CI = differentially characteristic cytoplasmic interaction (4) between oC and X, determined by the genetic constitution of the biological species. ▬▬▬>= migration, where permeability to the material involved is relatively high; and ~~~~->, where relatively low. <▬▬▬>= chemical reactions. ▬▬▬>= energy changes of X; diffusion is characteristically with the direction in which the concentration or activity of the constituent decreases, exchange adsorption may be with or against the direction of concentration or activity decrease.

Imunidade e permeabilidade celular

After going through the more important theories on cellular permeability, researches were undertaken with the purpose of proving the actual influence of the various degrees of cellular permeability on the phenomena of organic resistance against infections, and on the production of antibodies. Three groups of substances known to have action on cellular permeability were used; the first consisting of the following permeable substances: testos-terona, acetylcholine, and the spreading-factor of the staphyloccocus. The second group included substances which help in developing low cellular permeability: atropin, adrenalin and calcium. Finally, the third group consisted of a substance which helps to maintain normal permeability: cortin (an extract of the suprarenal cortex). In order to study the process developed by these elements with regard to organic resistance against infections, adult mice were inoculated with the following germs: K. pneumoniae, P. aeruginosa, S. enteriditis and D. pneumoniae, in the smallest possible amount capable of starting a mortal sep infection in approximately 24 hours, exception made of D. pneumonias which causes death in 48 hours. The animals were divided into groups of 10, a before taking the injections containing the germs, they were given the sub lances under observation, through their peritoneum of intramuscularly. T. animals that died were autopsied and blood was taken from their hearts an aseptic process so as not to introduce extraneous organisms. For the purpose of determining the development of antibodies (hem lysins, precipitins and aglutinins), rabbits were used, which had been prep ously immunized by a treatment consisting of 6 intravenous injections of polyvolent antigen made of sheep blood cells, fresh human serum, and of suspension of S. enteriditis. It was concluded that: Cellular permeability plays a very important part in the development infections. Permeable substances help the development of germ infections. Substances helping to develop low permeability proved not to have any influence worth mentioning. Substances helping to maintain normal permeability, such as coffin, it crease resistance against infections. The different substances used which have action on cellular permeability had no influence worth mentioning on the development of certain ant bodies (hemolysins, precipitins and aglutinins). It was admitted that the phenomena under study relative to resistance against infections are closely connected to the dynamics of the cellular elements, which circumstance is basically dependent on the permeability of Citations of cells.

O potassio plasmático em infecções bacterianas experimentais

Arrangement of potassium in the tissues having been mentioned, as well as the rôle it plays in some pathological processes such as suprarenal insufficiency, anaphylactic shock and shock caused by hemorrhage or traumatism, experiences were undertaken to establish the rates of plasma potassium during bacteria infections artificially developed in rabbits by K. pneumoniae. P. aeruginosa and S. enteridits. It was concluded that during the period of the infections, the rate of potassium of the plasma increases almost immediately after the inoculation and stays high when the infections are of a serious or mortal character; the rate continue to increase until the death of the animal occurs. When these infections are not very serious, as in the cases of infections resulting from inoculations of bacteria as not recent — and consequently with attenuated virulence — K pneumoniae, or P aeruginosa and S enteriditis, to which rabbits are naturally very resistant, the rate of potassium of the plasma increases after an intravenous inoculation of germs according to the septicemic period of the infection; however, when, because of its natural resistance, the animal overcomes the infection, the amount of potassium gradually decreases and finally gets back to the normal rate. The action of cortin on potassium of the plasma was also tested on animals suffering from acute infections caused by K. pneumoniae, which, under normal conditions cause death of the rabbits, nor did it increase the rate of potassium of the plasma when a larger amount of bacteria (300,000,000) was inoculated. However, cortin inoculated several times prevented a higher rate of potassium in the plasma during the development of the infection when a smaller number of bacteria (150,000,000) was inoculated, which quantity, under normal conditions, always causes mortal infections. When cortin is discontinued 20 hours after the inoculation of germs, the infection increases fastly and the animal dies in a very short time. Now, if the injections of cortin continue to be given every hour until the 26th hour instead of only until the 20th hour, the amount of potassium in the plasma — very high if the hormones substance is no longer inoculated — gradually becomes smaller and finally comes back to the normal rate if the inoculations continue to be made; it will increase again only if the substance is no longer injected; after a few hours the injection is gone, potassium is found to come back to its former rate, and in consequence the animal is perfectly cured of an infection otherwise mortal. ln view of the results thus obtained, it was concluded that, during the development of those infections, the checking of the rate of potassium of the plasma provided a means of controlling the resistance of a body suffering from an infection, that rate increasing when the infection is developing and becoming more severe, or getting back to normal when the infection decreases. The checking of the rate of potassium of the plasma also made known the action of cortin on the tissues, which is found to control the permeability of the cells to potassium. Suggestions were made that potassium of the plasma be thereofre checked during infections in the human body, to make possible proving that the phenomena studied in those animals also take place in the human body. In case this is found to be true, we sould possess an important element to check organic vitality during infections.

Effect of high pressure processing on the microbiology of skin-vacuum packaged sliced meat products: cooked pork ham, dry cured pork ham and marinated beef loin

High hydrostatic pressure is being increasingly investigated in food processing. It causes microbial inactivation and therefore extends the shelf life and enhances the safety of food products. Yeasts, molds, and vegetative cells of bacteria can be inactivated by pressures in the range of 200 to 700 MPa. Microorganisms are more or less sensitive to pressure depending on several factors such as type, strain and the phase or state of the cells. In general, Gram-positive organisms are usually more resistant than Gram-negative. High pressure processing modifies the permeability of the cell membrane, the ion exchange and causes changes in morphology and biochemical reactions, protein denaturations and inhibition of genetic mechanisms. High pressure has been used successfully to extend the shelf life of high-acid foods such as refrigerated fruit juices, jellies and jams. There is now an increasing interest in the use of this technology to extend the shelf life of low-acid foods such as different types of meat products.

La résistance bactérienne aux antibiotiques.

50 years ago, the introduction of penicillin, followed by many other antibacterial agents, represented an often underestimated medical revolution. Indeed, until that time, bacterial infections were the prime cause of mortality, especially in children and elderly patients. The discovery of numerous new substances and their development on an industrial scale gave us the illusion that bacterial infections were all but vanquished. However, the widespread and sometimes uncontrolled use of these agents has led to the selection of bacteria resistant to practically all available antibiotics. Bacteria utilize three main resistance strategies: (1) modification of their permeability, (2) modification of target, and (3) modification of the antibiotic. Bacteria modify their permeability either by becoming impermeable to antibiotics, or by actively excreting the drug accumulated in the cell. As an alternative, they can modify the structure of the antibiotic's molecular target--usually an essential metabolic enzyme of the bacterium--and thus escape the drug's toxic effect. Lastly, they can produce enzymes capable of modifying and directly inactivating antibiotics. In addition, bacteria have evolved extremely efficient genetic transfer systems capable of exchanging and accumulating resistance genes. Some pathogens, such as methicillin-resistant Staphylococcus aureus and multiresistant Mycobacterium tuberculosis, have become resistant to almost all available antibiotics and there are only one or two substances still active against such organisms. Antibiotics are very precious drugs which must be administered to patients who need them. On the other hand, the development of resistance must be kept under control by a better comprehension of its mechanisms and modes of transmission and by abiding by the fundamental rules of anti-infectious chemotherapy, i.e.: (1) choose the most efficient antibiotic according to clinical and local epidemiological data, (2) target the bacteria according to the microbiological data at hand, and (3) administer the antibiotic in an adequate dose which will leave the pathogen no chance to develop resistance.

Diseño e implementación de un divisor de potencia en banda dual con estructuras metamateriales basadas en CSRRs

L'electromagnetisme és una branca de la física que està en continu estudi. Fins a mitjans de la dècada dels 60 es pensava que, per a la propagació de les ones electromagnètiques fos possible, els medis propagatius havien de presentar una permitivitat dielèctrica i una permeabilitat magnètica simultàniament positives. No obstant, Victor G. Veselago va revolucionar la teoria electromagnètica amb la idea dels medis amb ε i μ negatives i va donar amb això origen als medis metamaterials. En el present treball s'estudiaran els principis físics en els que es fonamenten els metamaterials. Es veuran algunes de les seves característiques que els converteixen en medis exòtics i com aquestes poden ser utilitzades en el desenvolupament de dispositius amb prestacions difícils d'obtenir amb les tecnologies convencionals. A continuació s'aplicaran els conceptes tractats en el disseny d'un inversor d'impedàncies implementat mitjançant ressonadors en anells oberts complementaris. Aquest dispositiu, que presentarà un funcionament en banda dual, serà utilitzat en el posterior disseny d'un divisor de potencia. Finalment es realitzarà la implementació física del divisor de potencia dissenyat i es verificarà el seu correcte funcionament amb les mesures pertinents.

In vitro engineering of human stratified urothelium: analysis of its morphology and function.

PURPOSE: Gastric or intestinal patches, commonly used for reconstructive cystoplasty, may induce severe metabolic complications. The use of bladder tissues reconstructed in vitro could avoid these complications. We compared cellular differentiation and permeability characteristics of human native with in vitro cultured stratified urothelium. MATERIALS AND METHODS: Human stratified urothelium was induced in vitro. Morphology was studied with light and electron microscopy and expression of key cellular proteins was assessed using immunohistochemistry. Permeability coefficients were determined by measuring water, urea, ammonia and proton fluxes across the urothelium. RESULTS: As in native urothelium the stratified urothelial construct consisted of basal membrane and basal, intermediate and superficial cell layers. The apical membrane of superficial cells formed villi and glycocalices, and tight junctions and desmosomes were developed. Immunohistochemistry showed similarities and differences in the expression of cytokeratins, integrin and cellular adhesion proteins. In the cultured urothelium cytokeratin 20 and integrin subunits alpha6 and beta4 were absent, and symplekin was expressed diffusely in all layers. Uroplakins were clearly expressed in the superficial umbrella cells of the urothelial constructs, however, they were also present in intermediate and basal cells. Symplekin and uroplakins were expressed only in the superficial cells of native bladder tissue. The urothelial constructs showed excellent viability, and functionally their permeabilities for water, urea and ammonia were no different from those measured in native human urothelium. Proton permeability was even lower in the constructs compared to that of native urothelium. CONCLUSIONS: Although the in vitro cultured human stratified urothelium did not show complete terminal differentiation of its superficial cells, it retained the same barrier characteristics against the principal urine components. These results indicate that such in vitro cultured urothelium, after being grown on a compliant degradable support or in coculture with smooth muscle cells, is suitable for reconstructive cystoplasty.

Surfactant protein-D and exposure to bioaerosols in wastewater and garbage workers.

PURPOSE: Bioaerosols and their constituents, such as endotoxins, are capable of causing an inflammatory reaction at the level of the lung-blood barrier, which becomes more permeable. Thus, it was hypothesized that occupational exposure to bioaerosols can increase leakage of surfactant protein-D (SP-D), a lung-specific protein, into the bloodstream. METHODS: SP-D was determined by ELISA in 316 wastewater workers, 67 garbage collectors, and 395 control subjects. Exposure was assessed with four interview-based indicators and by preliminary endotoxin measurements using the Limulus amoebocyte lysate assay. Influence of exposure on serum SP-D was assessed by multiple linear regression considering smoking, glomerular function, lung diseases, obesity, and other confounders. RESULTS: Overall, mean exposure levels to endotoxins were below 100 EU/m(3). However, special tasks of wastewater workers caused higher endotoxin exposure. SP-D concentration was slightly increased in this occupational group and associated with the occurrence of splashes and contact to raw sewage. No effect was found in garbage collectors. Smoking increased serum SP-D. No clinically relevant correlation between spirometry results and SP-D concentrations appeared. CONCLUSIONS: These results support the hypothesis that inhalation of bioaerosols, even at low concentrations, has a subclinical effect on the lung-blood barrier, the permeability of which increases without associated spirometric changes.

Comparison of time-lapse GPR data collected under natural and forced infiltration conditions to estimate vadose zone hydraulic parameters

Time-lapse crosshole ground-penetrating radar (GPR) data, collected while infiltration occurs, can provide valuable information regarding the hydraulic properties of the unsaturated zone. In particular, the stochastic inversion of such data provides estimates of parameter uncertainties, which are necessary for hydrological prediction and decision making. Here, we investigate the effect of different infiltration conditions on the stochastic inversion of time-lapse, zero-offset-profile, GPR data. Inversions are performed using a Bayesian Markov-chain-Monte-Carlo methodology. Our results clearly indicate that considering data collected during a forced infiltration test helps to better refine soil hydraulic properties compared to data collected under natural infiltration conditions

Derivation of soil-specific streaming potential electrical parameters from hydrodynamic characteristics of partially saturated soils

Water movement in unsaturated soils gives rise to measurable electrical potential differences that are related to the flow direction and volumetric fluxes, as well as to the soil properties themselves. Laboratory and field data suggest that these so-called streaming potentials may be several orders of magnitudes larger than theoretical predictions that only consider the influence of the relative permeability and electrical conductivity on the self potential (SP) data. Recent work has improved predictions somewhat by considering how the volumetric excess charge in the pore space scales with the inverse of water saturation. We present a new theoretical approach that uses the flux-averaged excess charge, not the volumetric excess charge, to predict streaming potentials. We present relationships for how this effective excess charge varies with water saturation for typical soil properties using either the water retention or the relative permeability function. We find large differences between soil types and the predictions based on the relative permeability function display the best agreement with field data. The new relationships better explain laboratory data than previous work and allow us to predict the recorded magnitudes of the streaming potentials following a rainfall event in sandy loam, whereas previous models predict values that are three orders of magnitude too small. We suggest that the strong signals in unsaturated media can be used to gain information about fluxes (including very small ones related to film flow), but also to constrain the relative permeability function, the water retention curve, and the relative electrical conductivity function.

Comment on "Streaming potential dependence on water-content in Fontainebleau sand" by V. Allegre, L. Jouniaux, F. Lehmann and P. Sailhac

Allegre et al. recently presented new experimental data regarding the dependence of the streaming potential coupling coefficient with the saturation of the water phase. Such experiments are important to model the self-potential response associated with the flow of water in the vadose zone and the electroseismic/seismoelectric conversions in unsaturated porous media. However, the approach used to interpret the data is questionable and the conclusions reached by Allegre et al. likely incorrect

Early antibiotic administration affects the gut barrier function and the immune response to oral antigen in suckling rats

Abstract: The increasingly high hygienic standards characterizing westernized societies correlate with an increasingly high prevalence of allergic disease. Initially based on these observations, the hygiene hypothesis postulates that reduced microbial stimulation during infancy impairs the immune system development and increases the risk of allergy. Moreover, there is increasing evidence that the crosstalk existing between the intestine and the resident microbiota is crucial for gut homeostasis. In particular, bacterial colonization of the gut affects the integrity of the gut barrier and stimulates the development of the gut associated immune tissue, both phenomena being essential for the immune system to mount a controlled response to food antigens. Therefore, alterations in the microbial colonization process, by compromising the barrier homeostasis, may increase the risk of food allergy. In this context, antibiotic treatment, frequently prescribed during infancy, affects gut colonization by bacteria. However, little is known about the impact of alterations in the colonization process on the maturation of the gut barrier and on the immunological response to oral antigens. The objective of this work was to determine the impact of a commercial antibiotic preparation employed in pediatric settings on the gut barrier status at the critical period of the suckling/weaning transition and to evaluate the physiological consequences of this treatment in terms of immune response to food antigens. We established an antibiotic-treated suckling rat model relevant to the pediatric population in terms of type, dose and route of administration of the antibiotic and of changes in the patterns of microbial colonization. Oral tolerance to a novel luminal antigen (ovalbumin) was impaired when the antigen was introduced during antibiotic treatment. These results paralleled to alterations in the intestinal permeability to macromolecules and reduced intestinal expression of genes coding for the major histocomptatibility complex II molecules, which suggest a reduced capacity of antigen handling and presentation in the intestine of the antibiotic-treated animals. In addition, low luminal IgA levels and reduced intestinal expression of genes coding for antimicrobial proteins suggest that protection against pathogens was reduced under antibiotic treatment. In conclusion, we observed in suckling rats that treatment with abroad-spectrum antibiotic commonly used in pediatric practices reduced the capacity of the immune system to develop tolerance. The impact of the antibiotic treatment on the immune response to the antigen-was likely mediated by the alterations of the gut microbiota, through impairment in the mechanisms of antigen handling and presentation. This work reinforces the body of data supporting a key role of the intestinal microbiota modulating the risk of allergy development and leads us to propose that the introduction of new food antigens should be avoided during antibiotic treatment in infants. Résumé: L'augmentation du niveau d'hygiène caractérisant les sociétés occidentales semble être fortement corrélée avec l'augmentation des cas d'allergie dans ces pays. De cette observation est née l'hypothèse qu'une diminution des stimuli microbiens pendant l'enfance modifie le développement du système immunitaire augmentant ainsi le risque d'allergie. En ce sens, un nombre croissant de données indiquent que les interactions existant entre l'intestin et les bactéries résidantes sont cruciales pour l'équilibre du système. En effet, la présence de bactéries dans l'intestin affecte l'intégrité de sa fonction de barrière et stimule le développement du système immunitaire intestinal. Ces deux paramètres étant essentiels à la mise en place d'une réponse contrôlée vis à vis d'un antigène reçu oralement, toute modification du processus naturel de colonisation compromettant l'équilibre intestinal pourrait augmenter le risque d'allergie. Les traitements aux antibiotiques, fréquemment prescrits en pédiatrie, modifient de façon conséquente le processus de colonisation bactérienne. Cependant peu de données existent concernant l'impact d'une altération du processus de colonisation sur la maturation de la barrière intestinale et de la réponse immunitaire dirigée contre un antigène. L'objectif de ce travail était de déterminer l'impact d'un antibiotique commercial et employé en pédiatrie sur l'état de la barrière intestinale au moment critique du sevrage et d'évaluer les conséquences physiologiques d'un tel traitement sur la réponse immune à un antigène alimentaire. Nous avons mis en place un modèle de rats allaités, traités à l'antibiotique, le plus proche possible des pratiques pédiatriques, en terme de nature, dose et voie d'administration de l'antibiotique. Nous avons constaté que l'établissement de la tolérance orale à un nouvel antigène (l'ovalbumine) est altéré quand celui-ci est donné pour la première fois au cours du traitement antibiotique. Ces résultats coïncident avec une diminution de la perméabilité intestinale aux macromolécules, ainsi qu'avec une diminution de l'expression des gènes codant pour les molécules du complexe majeur d'histocomptatibilité de classe II, suggérant une modification de l'apprêtement et de la présentation de l'antigène au niveau intestinal chez les rats traités à l'antibiotique. De plus, un faible taux d'IgA et une diminution de l'expression des gènes codant pour des protéines antimicrobiennes, observés après l'administration d'antibiotique, laissent à penser que la protection contre un pathogène est diminuée lors d'un traitement antibiotique. En conclusion, nous avons observé qu'un traitement antibiotique à large spectre d'activité, couramment utilisé en pédiatrie, réduit la capacité d'induction de la tolérance orale chez le rat allaité. L'impact du traitement antibiotique sur la réponse immune semble induite par l'altération de la flore intestinale via son effet sur les mécanismes d'apprêtement et de présentation de l'antigène. Ce travail renforce l'ensemble des données existantes qui accorde à la flore intestinale un rôle clef dans la modulation du risque de développement d'allergie et nous amène à recommander d'éviter l'introduction d'un nouvel aliment lorsqu'un enfant est traité aux antibiotiques.