834 resultados para Habit
Resumo:
There is a widespread reporting habit of combining the outcomes for patients with rest pain (Fontaine III) and tissue loss (Fontaine IV) under the single category of critical leg ischaemia (CLI). This study focused on patients with ischaemic tissue loss treated with infrainguinal bypass surgery (IBS). All patients included in the study were treated at Helsinki University Central Hospital in 2000-2007. First, ulcer healing time after IBS and factors influencing healing time were prospectively assessed in 2 studies including 148 and 110 patients, respectively. Second,the results of redo IBS were retrospectively evaluated in 593 patients undergoing primary IBS for CLI with tissue loss . Third,long-term outcome were retrospectively analysed in 636 patients who underwent IBS for CLI with tissue loss . Fourth, the outcome of IBS was retrospectively compared with endovascular treatment (PTA) of the infrapopliteal arteries in 1023 CLI patients. Fifth, the influence multidrug resistant Pseudomans aeruginosa (MDR Pa) bacteria contamination in CLI patients treated with IBS was retropectively assessed. Sixty-four patients with positive MDR Pa -culture were matched with 64 MDR Pa - negative controls. Complete ulcer healing rate, including the ischemic ulcers and incisional wounds, was 40% at 6 months after IBS and 75% at one year. Diabetes was a risk factor for prolonged complete ulcer healing time. Ischaemic tissue lesions located in mid-and hindfoot healed poorly. At one year after IBS 50% of the patients were alive with salvaged leg and completely healed ulcers. The absence of gap between tertiary graft patency and leg salvage rates indicates the importance of a patent infrainguinal graft to save a leg with ischaemic tissue loss. Long-term survival for patients with ischaemic tissue loss was poor, 38% at 5 years. Only 30% of the patients were alive without amputation at 5 years. Several of the patient comorbidities increased independently the mortality risk; coronary artery disease, renal insufficiency, chronic obstructive lung disease and high age. When both PTA and bypass is feasible, infrapopliteal PTA as a first-line strategy is expected to achieve similar long-term results to bypass surgery in CLI when redo surgery is actively utilized. MDR Pa in a patient with CLI should be considered as a serious event with increased risk of early major amputation or death. Conclusion: Despite a successful infrainguinal bypass healing of the ischaemic ulcers and incisional wounds ulcer healing is a slow process especially in diabetics. Bypass surgery and PTA improve the outcome of the ischaemic leg but the mortality rate of the patients is high due to their severe comorbidities.
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Phlebiopsis gigantea has been for a long time known as a strong competitor against Heterobasidion annosum and intensively applied as a biological control agent on stump surfaces of Picea abies in Fennoscandia. However, the mechanism underlying its antagonistic activity is still unknown. A primary concern is the possible impact of P. gigantea treatment on resident non-target microbial biota of conifer stumps. Additional risk factor is the potential of P. gigantea to acquire a necrotrophic habit through adaptation to living wood tissues. This study focused on the differential screening of several P. gigantea isolates from diverse geographical sources as well as the use of breeding approach to enhance the biocontrol efficacy against H. annosum infection. The results showed a significant positive correlation between growth rate in wood and high biocontrol efficacy. Furthermore, with aid of breeding approach, several progeny strains were obtained that had better growth rate and control efficacy than parental isolates. To address the issue of the potential of P. gigantea to acquire necrotrophic capability, a combination of histochemical, molecular and transcript profiling (454 sequencing) were used to investigate the interactions between these two fungi and ten year old P. sylvestris seedlings. The results revealed that both P. gigantea and H. annosum provoked strong necrotic lesions, but after prolonged incubation, P. gigantea lesions shrank and ceased to expand further. Tree seedlings pre-treated with P. gigantea further restricted H. annosum-induced necrosis and had elevated transcript levels of genes important for lignification, cell death regulation and jasmonic acid signalling. These suggest that induced localized resistance is a contributory factor for the biocontrol efficacy of P.gigantea, and it has a comparatively limited necrotrophic capability than H. annosum. Finally, to investigate the potential impact of P. gigantea on the stump bacterial biota, 16S rDNA isolated from tissue samples from stumps of P. abies after 1-, 6- and 13-year post treatment was sequenced using bar-coded 454 Titanium pyrosequencing. Proteobacteria were found to be the most abundant at the initial stages of stump decay but were selectively replaced by Acidobacteria at advanced stages of the decay. Moreover, P. gigantea treatment significantly decreased the bacterial richness at initial decay stage in the stumps. Over time, the bacterial community in the stumps gradually recovered and the negative effects of P. gigantea was attenuated.
Resumo:
The habit of "drinking smoke" , meaning tobacco smoking, caused a true controversy in early modern England. The new substance was used both for its alleged therapeutic properties as well as its narcotic effects. The dispute over tobacco continues the line of written controversies which were an important means of communication in the sixteenth and seventeenth century Europe. The tobacco controversy is special among medical controversies because the recreational use of tobacco soon spread and outweighed its medicinal use, ultimately causing a social and cultural crisis in England. This study examines how language is used in polemic discourse and argumentation. The material consists of medical texts arguing for and against tobacco in early modern England. The texts were compiled into an electronic corpus of tobacco texts (1577 1670) representing different genres and styles of writing. With the help of the corpus, the tobacco controversy is described and analyzed in the context of early modern medicine. A variety of methods suitable for the study of conflict discourse were used to assess internal and external text variation. The linguistic features examined include personal pronouns, intertextuality, structural components, and statistically derived keywords. A common thread in the work is persuasive language use manifested, for example, in the form of emotive adjectives and the generic use of pronouns; the latter is especially pronounced in the dichotomy between us and them. Controversies have not been studied in this manner before but the methods applied have supplemented each other and proven their suitability in the study of conflictive discourse. These methods can also be applied to present-day materials.
Resumo:
Nurmiheinien merkitys maailmanlaajuisesti on merkittävä, sillä noin 69 % maapallon peltopinta-alasta on pysyvää laidunmaata tai niittyä. Suomessa nurmien osuus on noin 29 %, ja tuotanto perustuu pääosin intensiiviseen säilörehuntuotantoon. Yleisin nurmiheinälaji Suomessa on timotei (Phleum pratense ssp. pratense L.). Timotei on talvenkestävä ja soveltuu siksi pohjoisiin kasvuoloihin. Timoteilajikkeita jalostettaessa pohjoista alkuperää olevia vanhempaislinjoja käytetään hyvän talvenkestävyyden varmistamiseksi, eteläisiä tavoiteltaessa nopeaa kasvurytmiä. Ilmaston muutoksen ennustetaan lisäävän erilaisia äärioloja kuten myrskyjä ja sateita. Vuorokauden keskilämpötila nousee ja kasvukausi pidentyy. Lisäksi talvet muuttuvat sateisemmiksi. Muutokset näkyvät erityisesti pohjoisissa kasvuympäristöissä. Tutkimuksessa haluttiinkin selvittää eri alkuperää edustavien timoteilajikkeiden ja linjojen kylmänkestävyyttä, kasvu-, ja kehitysnopeutta sekä vernalisaation vaikutusta. Lisäksi tutkittiin syysviljojen vernalisaatiovasteen mittaamiseen käytettyjen menetelmien soveltuvuutta nurmille. Tutkimukseen kuului kaksivuotinen peltokoe sekä kasvatuskaappikoe. Vernalisaatio nopeutti timotein kasvua ja kehitystä. Tutkimuksen perusteella eteläistä alkuperää olevilla lajikkeilla kasvu- ja kukintavalmius oli olemassa ilman vernalisaatiota. Pohjoisilla lajikkeilla oli suurempi vernalisaatiovaste ja niiden kukkiminen ja kasvu nopeutui vernalisaation myötä. Vernalisaatiolla oli vaikutusta myös kasvuston rakenteeseen. Generatiivisten versojen määrä lisääntyi vernalisaation myötä, kun taas vegetatiivisten versojen määrä väheni. Kylmänkestävyys oli tutkimuksen perusteella riippuvainen syksyn karaistumisjakson pituudesta sekä jakson lämpösummasta (FH-COLD). Korkea keskilämpötila ja lyhyt karaistumisjakso heikensivät kylmänkestävyyttä. Vastaavasti karaistumiskauden lämpötilan ollessa välillä 0 °C:ta ja + 5 °C:ta ja jakson pituuden kasvaessa kylmänkestävyys lisääntyi. Tutkimuksen perusteella vernalisaatiolla oli selvä vaikutus timotein kasvuun ja kehitykseen. Pohjoista alkuperää olevat timoteit reagoivat vernalisaatioon eteläisiä enemmän. Osa pohjoisista linjoista vaati vernalisaation generatiivisten versojen muodostumiseen. Syysviljojen vernalisaatiovasteen mittausmenetelmät soveltuvat osin myös puhtaiden timoteilajikkeiden vernalisaation seurantaan.
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Potassium titanyl phosphate (KTP) is a relatively new nonlinear optical material with excellent combination of physical properties. This paper presents the combined etching and X-ray topographic studies carried out on KTP crystals with a view to characterizing their defects. KTP crystals employed in this investigation were grown from flux. Optical microscopic study of habit faces revealed growth layers and growth hillocks on (100) and (011) faces respectively. Etching of (011) habit faces proved that growth hillocks corresponded to the emergence point of dislocation out crops on these faces. The suitability of the new etchant to reveal dislocation was confirmed by etching the matched pairs obtained by cleaving. The defects present in the crystal were also studied by X-ray topography. The defect configuration in these crystals is characteristic of crystals grown from solution. The dislocations arc predominantly linear with their origin either at the nucleation centre or inclusions. In general, grown crystals were found to have low dislocation density and often large volumes of crystals free from dislocation could be obtained.
Resumo:
Plate-shaped products resulting from martensitic, diffusional, and mixed mode transformations in zirconium-base alloys are compared. in the present study. These alloys are particularly suitable for the comparison in view of the fact that the lattice correspondence between the parent beta (bcc) and the product alpha (hcp) or gamma-hydride (fct) phases are remarkably similar for different types of transformations. Crystallographic features such as orientation relations, habit planes, and interface structures associated with these transformations have been compared:, with a view toward examining whether the transformation mechanisms have characteristic imprints on these experimental observables. Martensites exhibiting dislocated lath, internally twinned plate, and self-accommodating three-plate cluster morphologies have been encountered in Zr-2.5Nb alloy. Habit planes corresponding to all these morphologies have been found to be consistent with the predictions based on the invariant plane strain (IFS) criterion. Different morphologies have been found to reflect the manner in which the neighboring martensite variants are assembled. Lattice-invariant shears (LISs) for all these cases have been identified to be either {10 (1) over bar 1}(alpha) ((1) over bar 123)(alpha) slip or twinning on (10 (1) over bar 1)(alpha) planes. Widmanstatten alpha precipitates, forming in a step-quenching treatment, have been shown to have a lath morphology, the alpha/beta interface being decorated with a periodic array of (c + a) dislocations at a spacing of 8 to 10 nm. The line vectors of these dislocations are nearly parallel to the invariant lines. The alpha precipitates, forming in the retained beta phase on aging, exhibit an internally twinned structure with a zigzag habit plane. Average habit planes for the morphologies have been found to lie near the {103}(beta) - {113}(beta) poles, which are close to the specific variant of the {112}(beta) plane, which transforms into a prismatic plane of the type {1 (1) over bar 00}(alpha). The crystallography of the formation of the gamma-hydride phase (fct) from both the alpha and beta phases is seen to match the IFS predictions. While the beta-gamma transformation can be treated approximately as a simple shear on the basal plane involving a change in the stacking sequence, the alpha-gamma transformation call be conceptually broken into a alpha --> beta transformation following the Burgers correspondence and the simple beta-gamma shear process. The active eutectoid decomposition in the Zr-Cu system, beta --> alpha + beta', has been described in terms of cooperative growth of the alpha phase from the beta phase through the Burgers correspondence and of the partially ordered beta' (structurally similar to the equilibrium Zr2Cu phase) through an ordering process. Similarities and differences in crystallographic features of these transformations have been discussed. and the importance of the invariant line vector in deciding the geometry of the corresponding habit planes has been pointed out.
Resumo:
Lantana camara, a shrub of Central and South American origin, has become invasive across dry forests worldwide. The effect of the thicket-forming habit of L. camara as a dispersal and recruitment barrier in a community of native woody seedlings was examined in a 50-ha permanent plot located in the seasonally dry forest of Mudumalai, southern India. Sixty 100-m(2) plots were enumerated for native woody seedlings between 10-100 cm in height. Of these, 30 plots had no L. camara thickets, while the other 30 had dense thickets. The frequency of occurrence and abundance of seedlings were modelled as a function of dispersal mode (mammal, bird or mechanical) and affinities to forest habitats (dry forest, moist forest or ubiquitous) as well as presence or absence of dense L. camara thickets. Furthermore, frequency of occurrence and abundance of individual species were also compared between thickets and no L. camara. At the community level, L. camara density, dispersal mode and forest habitat affinities of species determined both frequency of occurrence and abundance of seedlings, with the abundance of dry-forest mammal-dispersed species and ubiquitous mechanically dispersed species being significantly lower under L. camara thickets. Phyllanthus emblica and Kydia calycina were found to be significantly less abundant under L. camara, whereas most other species were not affected by the presence of thickets. It was inferred that, by affecting the establishment of native tree seedlings, L. camara thickets could eventually alter the community composition of such forests.
Resumo:
Defending a large social insect colony containing several thousands of workers requires the simultaneous action of many individuals. Ideally this action involves communication between the workers, enabling coordinated action and a fast response. The Asian dwarf honeybee, Apis florea, is a small honeybee with an open nesting habit and a comparatively small colony size, features that leave them particularly exposed to predators. We describe here a novel defence response of these bees in which the emission of an initial warning signal from one individual (“piping”) is followed 0.3 to 0.7 seconds later by a general response from a large number of bees (“hissing”). Piping is audible to the human ear, with a fundamental frequency of 384 ± 31Hz and lasting for 0.82 ± 0.35 seconds. Hissing is a broad band, noisy signal, clearly audible to the human observer and produced by slight but visible movements of the bees' wings. Hissing begins in individuals close to the piping bee, spreads rapidly to neighbours and results in an impressive coordinated crescendo occasionally involving the entire colony. Piping and hissing are accompanied by a marked decrease, or even cessation, of worker activities such as forager dancing and departures from the colony. We show that whereas hissing of the colony can be elicited without piping, the sequential and correlated piping and hissing response is specific to the presence of potential predators close to the colony. We suggest that the combined audio-visual effect of the hissing might deter small predators, while the cessation of flight activity could decrease the risk of predation by birds and insects which prey selectively on flying bees.
Resumo:
he crystallographic and morphological aspect associated with the formation of γ hydride phase (fct) from the β phase in β abilized Zr-20%Nb alloy has been reported. In this paper the βto γ transformation has been considered in the terms of the phenomenological theory of martensitic crystallography in order to predict the crystallographic features of the γ hydride in the β to γ transformation. The prediction made in the present analysis has been found to match very closely to the experimentally observed habit plane. The possibility of the α to γ transition through the formation of a transient β configuration has been examined.
Resumo:
Electrodeposition of nickel/barium hexa-aluminate (Ni/BHA) composite coatings has been carried out from a Watt's bath on mild steel substrate. BHA powders with plate habit were synthesized by solution combustion synthesis followed by heat treatment to ensure complete conversion to the hexa-aluminate phase. Heat treated material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with X-ray analysis. The dispersion behaviour and stability of BHA suspensions with cationic and anionic surfactants at room temperature were studied by dynamic light scattering under different pH. The influence of BHA concentration in the electrolytic bath, deposition temperature, pH, current density and duty cycle on particle incorporation in the coatings were studied and conditions for maximum particle incorporation were established. Coatings with a roughness of about 0 center dot 4 mu m were produced by using this technique. Effect of BHA content on microhardness was also investigated. A reasonably good thickness of the coatings was achieved in a given set of conditions.
Resumo:
Single crystals of lithium D-isoascorbate monohydrate (LDAM), (C6H7O6Li center dot H2O), are grown by a solution growth method. The crystal structure of LDAM is solved using single crystal X-ray diffraction. The space group is orthorhombic P2(1)2(1)2(1) with four formula units per unit cell and lattice parameters a = 7.7836(3) angstrom, b = 8.7456(3) angstrom, and c = 11.0368(4) angstrom. Solubility of the material in water is determined thermogravimetrically and found to have a positive temperature coefficient of solubility. Large optical quality single crystals are subsequently grown from aqueous solution by a slow cooling method. The crystal has a bulky prismatic habit and among the prominent faces the c face appears as the only principal morphological face. The crystal exhibits a (010) cleavage. Dielectric spectroscopy reveals a nearly Debye type Cole-Cole behavior with anisotropy in relaxation. Optical transmission range is found to be from 300 to 1400 nm. The principal refractive indices of this biaxial crystal, measured using Brewster's angle method, at wavelengths 405, 543, and 632.8 nm, show high dispersion. The crystal is negative biaxial with 2V(z) = 107.8 degrees (405 nm) and belongs to the Hobden class 3. Theoretically generated type 1 and type 2 second order phase matching curves match very well with the experimental results. The second-order nonlinear coefficient d(14) was determined to be 7 x 10(-13) m/V. For the optimum phase matching direction (type 2), the second-order effective nonlinear coefficient and the walk off angle are determined to be 0.84 times d(14) and 3.5 degrees respectively. The crystal possesses high multiple surface damage thresholds of 18 GW/cm(2) and 8 GW/cm(2) at laser wavelengths 1064 and 532 nm, respectively.
Resumo:
Lithium L-Ascorbate dihydrate (LLA) is a new metal organic nonlinear optical crystal belonging to the saccharide family. Single crystals of LLA were grown from aqueous solution. Solubility of the crystal has a positive temperature coefficient facilitating growth by slow cooling. Rietveld refinement was used to confirm the phase formation. The crystal has prismatic habit with (010), (001) and (10-1) prominent faces. Thermal analysis shows that the crystal is stable up to 102 degrees C. Transmission spectrum of the crystal extends from 302 nm to 1600 nm. Dielectric spectroscopic analysis revealed Cole Cole behaviour and prominent piezoelectric resonance peaks were observed in the range of 100-200 kHz. Second harmonic generation (SHG) conversion efficiency of up to 2.56 times that of a phase matched KDP crystal was achieved when the (010) plate of LLA single crystal was rotated about the +ve c axis, by 9.4 degrees in the clockwise direction. We also observed SHG conical sections which were attributed to noncollinear phase matching. The observation of the third conical section suggests very high birefringence and large nonlinear coefficients. A detailed study of surface laser damage showed that the crystal has high multiple damage thresholds of 9.7 GW cm(-2) and 42 GW cm(-2) at 1064 nm and 532 nm radiation respectively. (C) 2012 Elsevier B.V. All rights reserved.
Resumo:
Resumen: El autor aborda un tema que a veces pasa inadvertido aun para muchos adherentes al iusnaturalismo: el conocimiento de la ley natural. Mientras abundan estudios que centran sus argumentos en la existencia de esta normativa supra positiva o que ahondan su ontología y extensión, sin embargo a veces no se repara en una cuestión liminar que resulta necesario dilucidar: ¿cómo se conocen los principios y las conclusiones de la ley natural?, ¿es naturalmente conocida?, ¿qué se entiende por “naturalmente”? Sobre el contenido de la ley natural el documento afirma que “no es un conjunto cerrado y completo de normas morales, sino la fuente de inspiración constante, presente y operativa de las diversas etapas de la economía de la salvación”. El término “percepción” hace referencia a una “experiencia” y que por tanto es exterior. Se concluye entonces que consiste en un conocimiento objetivo (no innato) de los preceptos morales, más allá de la presencia natural de un hábito que permite su captación (sindéresis).
Resumo:
Este trabajo intenta presentar una respuesta desde el Personalismo ontológico a la Bioética principista, fundándose en una ética de las virtudes que apela a la clásica noción de virtud moral como hábito operativo bueno que hace buena la obra y bueno al que obra. Se analizan así, antropológica y éticamente, las virtudes de la prudencia, de la justicia, de la fortaleza y de la templanza, mostrando la aplicación de cada una de ellas al campo bioético.
Resumo:
Integran este número de la revista ponencias presentadas en Studia Hispanica Medievalia VIII: Actas de las IX Jornadas Internacionales de Literatura Española Medieval, 2008, y de Homenaje al Quinto Centenario de Amadis de Gaula.