977 resultados para Over-complete Discretewavelet Transformation


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Inorganic phosphate (Pi) homeostasis in multi-cellular eukaryotes depends not only on Pi influx into cells, but also on Pi efflux. Examples in plants for which Pi efflux is crucial are transfer of Pi into the xylem of roots and release of Pi at the peri-arbuscular interface of mycorrhizal roots. Despite its importance, no protein has been identified that specifically mediates phosphate efflux either in animals or plants. The Arabidopsis thaliana PHO1 gene is expressed in roots, and was previously shown to be involved in long-distance transfer of Pi from the root to the shoot. Here we show that PHO1 over-expression in the shoot of A. thaliana led to a two- to threefold increase in shoot Pi content and a severe reduction in shoot growth. (31) P-NMR in vivo showed a normal initial distribution of intracellular Pi between the cytoplasm and the vacuole in leaves over-expressing PHO1, followed by a large efflux of Pi into the infiltration medium, leading to a rapid reduction of the vacuolar Pi pool. Furthermore, the Pi concentration in leaf xylem exudates from intact plants was more than 100-fold higher in PHO1 over-expressing plants compared to wild-type. Together, these results show that PHO1 over-expression in leaves leads to a dramatic efflux of Pi out of cells and into the xylem vessel, revealing a crucial role for PHO1 in Pi efflux.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The marsupial and placental mammals originated at a time when the pattern of geographical barriers (oceans, shallow seas and mountains) was very different from that of today, and climates were warmer. The sequence of changes in these barriers, and their effects on the dispersal of the mammal families and on the faunas of mammals in the different continents, are reviewed. The mammal fauna of South America changed greatly in the Pliocene/Pleistocene, when the newly-complete Panama Isthmus allowed the North American fauna to enter the continent and replace most of the former South American mammal families. Marsupial, but not placental, mammals reached Australia via Antarctica before Australia became isolated, while rats and bats are the only placentals that dispersed naturally from Asia to Australia in the late Cenozoic. Little is known of the early history of the mammal fauna of India. A few mammal families reached Madagascar from Africa in the early Cenozoic over a chain of islands. Africa was isolated for much of the early Cenozoic, though some groups did succeed in entering from Europe. Before the climate cooled in the mid-Cenozoic, the mammal faunas of the Northern Hemisphere were much richer than those of today.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

From an anthropological perspective, formal post-secondary schooling is not an abstractentity with an intrinsic value that everyone finds desirable, but rather one alternative among many that young people evaluate from their different positions in the social field. The problem discussed in this paper is the diverging life trajectories that young men and women in a concrete rural context, at the end of the 20th century, shape for themselves at the ages of 14-16, a moment of decision created by national legislation regarding mandatory education (LGE, 1970, General Education Law, and LOGSE, 1990, General Organic Law of the Education System). Despite a strong cultural norm of equal inheritance divided among all children, male and female, and despite the equal educational opportunities provided by the Spanish State, different meanings of possession and use-rights over land and the resulting culturally accepted gendered division of work converge to orient men and women differently towards post-secondary schooling. Observation of the age, gender, and civil status structure of the population led to the preliminary query: Why do men and women, in this town, behave differently with respect to migration and marriage? The main hypothesis was that women’s longer school trajectories and resulting migration and men’s anchoring in the town and their higher rates of celibacy were not drastic changes in values, in the positional-relational sense of Bourdieu (1988, 2002), but the current outcome of previously existing dissimilar relations to property that produce dissimilar mobility. Through their schooling and work choices, young men and women, at very early ages, locate themselves in, or decide to belong to, different contexts that later reveal very different possibilities of finding marriage partners. This paper is based on an ethnographic study of a small rural town (302 inhabitants in 1950; 193 in 2000) near Leon. Although this paper deals with the situation in the final decades of the 20th century, we must also consider the first half of the century, where some elements that shape this situation have their roots. Fieldwork was carried out between 1988 and 2001, in periods of differing length and intensity. The social subjects discussed here are the domestic unit and its component members. They were studied in conjunction, analyzing the life-trajectory decisions of specific persons in the framework of the domestic unit and the relations among people and property which comprise it. The tried-and-true methods of ethnographic research –participant observation, interviews, and life-histories, etc.- were employed. Archival research was also important for producing demographic data. Demographic analysis, the analysis of the composition and transformation of domestic units, and the creation of life trajectories were among the principal techniques used. The theoretical analysis was oriented by Bourdieu’s (2002) framework of the social field, habitus, and difference.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The major macromolecules on the surface of the parasitic protozoan Leishmania major appear to be down-regulated during transformation of the parasite from an insect-dwelling promastigote stage to an intracellular amastigote stage that invades mammalian macrophages. In contrast, the major parasite glycolipids, the glycoinositol phospholipids (GIPLs), are shown here to be expressed at near-constant levels in both developmental stages. The structures of the GIPLs from tissue-derived amastigotes have been determined by h.p.l.c. analysis of the deaminated and reduced glycan head groups, and by chemical and enzymic sequencing. The deduced structures appear to form a complete biosynthetic series, ranging from Man alpha 1-4GlcN-phosphatidylinositol (PI) to Gal alpha 1-3Galf beta 1-3Man alpha 1-3Man alpha 1-4GlcN-PI (GIPL-2). A small proportion of GIPL-2 was further extended by addition of a Gal residue in either alpha 1-6 or beta 1-3 linkage. From g.c.-m.s. analysis and mild base treatment, all the GIPLs were shown to contain either alkylacylglycerol or lyso-alkylglycerol lipid moieties, where the alkyl chains were predominantly C18:0, with lower levels of C20:0, C22:0 and C24:0. L. major amastigotes also contained at least two PI-specific phospholipase C-resistant glycolipids which are absent from promastigotes. These neutral glycolipids were resistant to both mild acid and mild base hydrolysis, contained terminal beta-Gal residues and were not lost during extensive purification of amastigotes from host cell membranes. It is likely that these glycolipids are glycosphingolipids acquired from the mammalian host. The GIPL profile of L. major amastigotes is compared with the profiles found in L. major promastigotes and L. donovani amastigotes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Un estudi observacional de pacients amb LES, atesos al University College de London Hospital entre 1976 i 2005, es va dur a terme per revisar les diferències entre homes i dones amb lupus pel que fa a les característiques clíniques, serologia i resultats. 439 dones i 45 homes van ser identificats. L'edat mitjana al diagnòstic va ser de 29,3 anys (12,6), sense diferències significatives entre homes i dones. El sexe femení es va associar significativament amb la presència d'úlceres orals i Ig M ACA. No hi va haver diferències significatives en la comparació de les altres variables. Durant aquest període de seguiment de trenta anys, relativament poques diferències han sorgit al comparar les freqüències de les característiques clíniques i serològiques en homes y dones amb lupus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The genes involved in the biosynthesis of biotin were identified in the hyphal fungus Aspergillus nidulans through homology searches and complementation of Escherichia coli biotin-auxotrophic mutants. Whereas the 7,8-diaminopelargonic acid synthase and dethiobiotin synthetase are encoded by distinct genes in bacteria and the yeast Saccharomyces cerevisiae, both activities are performed in A. nidulans by a single enzyme, encoded by the bifunctional gene bioDA. Such a bifunctional bioDA gene is a genetic feature common to numerous members of the ascomycete filamentous fungi and basidiomycetes, as well as in plants and oömycota. However, unlike in other eukaryota, the three bio genes contributing to the four enzymatic steps from pimeloyl-CoA to biotin are organized in a gene cluster in pezizomycotina. The A. nidulans auxotrophic mutants biA1, biA2 and biA3 were all found to have mutations in the 7,8-diaminopelargonic acid synthase domain of the bioDA gene. Although biotin auxotrophy is an inconvenient marker in classical genetic manipulations due to cross-feeding of biotin, transformation of the biA1 mutant with the bioDA gene from either A. nidulans or Aspergillus fumigatus led to the recovery of well-defined biotin-prototrophic colonies. The usefulness of bioDA gene as a novel and robust transformation marker was demonstrated in co-transformation experiments with a green fluorescent protein reporter, and in the efficient deletion of the laccase (yA) gene via homologous recombination in a mutant lacking non-homologous end-joining activity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The comparison of complete genomes has revealed surprisingly large numbers of conserved non-protein-coding (CNC) DNA regions. However, the biological function of CNC remains elusive. CNC differ in two aspects from conserved protein-coding regions. They are not conserved across phylum boundaries, and they do not contain readily detectable sub-domains. Here we characterize the persistence length and time of CNC and conserved protein-coding regions in the vertebrate and insect lineages. RESULTS: The persistence length is the length of a genome region over which a certain level of sequence identity is consistently maintained. The persistence time is the evolutionary period during which a conserved region evolves under the same selective constraints.Our main findings are: (i) Insect genomes contain 1.60 times less conserved information than vertebrates; (ii) Vertebrate CNC have a higher persistence length than conserved coding regions or insect CNC; (iii) CNC have shorter persistence times as compared to conserved coding regions in both lineages. CONCLUSION: Higher persistence length of vertebrate CNC indicates that the conserved information in vertebrates and insects is organized in functional elements of different lengths. These findings might be related to the higher morphological complexity of vertebrates and give clues about the structure of active CNC elements.Shorter persistence time might explain the previously puzzling observations of highly conserved CNC within each phylum, and of a lack of conservation between phyla. It suggests that CNC divergence might be a key factor in vertebrate evolution. Further evolutionary studies will help to relate individual CNC to specific developmental processes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La beca concedida ha anat destinada a desenvolupar la tesi doctoral que duu per nom "Les ciutats turístiques, les noves ciutats. Anàlisi de l'evolució del model turístic en destinacions de litoral madures a partir de l'anàlisi de paràmetres urbanístics". L’àrea d’estudi comprèn els municipis de Cambrils, Salou i La Pineda (Vila-seca) que conformen la Costa Daurada central, destinació madura de litoral mediterrani, que basa el seu desenvolupament d’acord el model turístic de sol i platja. Arribats en aquest punt de finalització de la beca, cal destacar que s’ha complert amb l'objectiu d'analitzar el procés de transformació de les ciutats turístiques, tot establint com el turisme litoral mediterrani s'ha convertit en un factor de creació de ciutat. Així mateix també s'han complert els objectius específics tals com: analitzar l'evolució de les destinacions turístiques consolidades del litoral mediterrani, recopilar informació per a la creació d'índexs i eines que serveixin per l'anàlisi del procés de tranformació de les ciutats turístiques a ciutats tradicionals a partir del tractament dels plans parcials, recopilar i analitzar les polítiques de planificació que han condicionat l'area d'estudi, modelitzar el procés de construcció de l'espai turístic a partir de l'establiment d'unes unitats bàsiques en la descripció i anàlisi territorial i paisatgístic, i crear un SIG per culminar el procés d'anàlisi tot creant una base de dades i la representació dels resultats en cartogradia temàtica. Pel que fa al disseny i l’execució de la metodologia, es poden considerar dos vessants, una vessant més qualitativa i una altra més quantitativa per al tractament de la informació recopilada. Igualment la generació de cartografia específica completa el procés amb la producció de cartografia específica, tal i com es desenvolupa en la present memòria. La tesi parteix del guió que contempla: un prier capítol d'introducció, un segon dedicat al marc teòric, un tercer apartat on s'exposaran les hipòtesis de les quals es parteix, i un quart dedicat a la metodologia. Pren especial importància l'apartat dedicat a l’ànalisi, així com el dedicat a la discussió dels resultats obtinguts, que es desenvoluparà en el sisè apartat. Per últim resta destacar el setè apartat dedicat a les conclusions a les que s'ha arribat.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

L'objectiu d'aquest projecte és que els nens i adolescents amb dolor crònic puguin gaudir d'una millor qualitat de vida. El projecte té dues línies de recerca complementàries. El primer objectiu específic és crear i adaptar instruments per avaluar l’experiència dolorosa a la població infantil. Dues són les mesures que s'han estudiat en escolars: l'escala numèrica verbal (vNRS-11) tant en paper com en format electrònic, i una versió modificada de la versió pediàtrica del Survey of Pain Attitudes (Peds-SOPA). El segon objectiu específic és avaluar els efectes de la teràpia cognitiva (TC) en una mostra de nens de 12 a 18 anys que pateixen dolor crònic. En concret, volem estudiar si algunes característiques personals i familiars dels joves (per exemple, creences relacionades amb la salut, intensitat del dolor, estratègies d'afrontament, expectatives del tractament) estan associades a l'adherència a les recomanacions terapèutiques i, en conseqüència, són variables que afavoreixen la recuperació d’aquests pacients. Un tractament de 10 sessions es porta a terme per aconseguir aquest objectiu. S’ofereix als pacients un conjunt d'habilitats i estratègies específiques per a què puguin exercir un major control dels seus símptomes i reduir l'impacte d'aquests en les seves vides. Els resultats d'aquests estudis seran de gran interès per millorar el maneig del dolor infantil. A més, els resultats determinaran quines són les variables associades amb l’adherència a les prescripcions terapèutiques. Aquest és un tema particularment d’interès pel fet de que un factor determinant de l’èxit clínic és el grau en què una persona s'adhereix a les recomanacions. D'altra banda, el desenvolupament de les mesures de dolor pediàtric és de gran rellevància tant per a clínics com per a investigadors, ja que moltes de les decisions clíniques es basen en allò que el pacient ha informat sobre el seu dolor.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Vegeu el resum a l'inici del document del fitxer adjunt"

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: To investigate the effect of the systematized use of intraluminal stents in Baerveldt shunts (BS) on early postoperative IOP control and complication rates. Methods: One hundred and twenty eyes with medically uncontrolled glaucoma were prospectively recruited to undergo BS implantation at Jules Gonin Eye Hospital, Switzerland. Baerveldt shunts were stented (full-length of the intraluminal tube) using a Supramid® 3.0 suture. A minority of shunts (37%) were also ligated intraoperatively and laser suture lysis performed postoperatively. Stent removals, either partial (retraction of 5mm) or complete, were carried out according to a predetermined protocol. Surgery was considered a success when IOP was ≤ 21mmHg and a minimum of 20% reduction from baseline was achieved with/without glaucoma medication (GMs). Hypotony related complications were defined as: choroidal effusions, shallow AC, hypotonous maculopathy or IOP≤5mmHg for over 2 weeks. Results: Mean age was 61.8 years (± standard deviation; ±21.5). Mean follow-up was 17.1 (±7.9) months. Mean preoperative IOP was 26.9 mmHg; mean IOP on the last visit 13.2 mmHg (p<0.001). At year one, the success rate was 87%. In 90% of eyes, IOP was ≤18 mmHg at last visit. Mean number of preoperatively GMs was 3.1; postoperatively 1.4 (p<0.001). Stent removals were performed in 87% of eyes (24% partial; 61% complete). 13% of eyes required no stent removal to reach target IOP. Complications were minor and infrequent (16%) and only 7% were hypotony related. Conclusions: Systematized use of intraluminal stents with Baerveldt aqueous shunts resulted in gradual and controlled IOP lowering with minimal hypotony-related complications. This may have important implications on clinical practice, given the rising rates of aqueous shunt implantation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Conference provided the opportunity for delegates to focus attention on issues of employment and retirement among older Irish people, issues such as preferences for work or retirement and barriers to staying in or returning to the workplace. It also afforded the opportunity to look at initiatives at the European level as well as recent developments in Ireland in relation to age discrimination, pension provision and lifelong learning initiatives Download the Report here

Relevância:

20.00% 20.00%

Publicador:

Resumo:

(Résumé de l'ouvrage) In 1953 the first fascicle of the first volume of the Corpus Christianorum was published. Now, fifty years later, this series has established itself as one of the great scientific enterprises in the field of patristic and medieval studies. We offer this birthday-present to ourselves, our old and new collaborators and our friends as a celebration of what has been achieved, as a survey of where we currently stand and as an insight into our future. The book opens with an essay on fifty years of the Corpus Christianorum. It tells the story of how the enterprise started as an ambitious yet limited project and how it developed into what it is today: a conglomerate of many different research projects located in different places all over the world. The second part presents a florilegium of patristic and medieval texts, all of which have been edited in the series, some only recently, others long ago. The selection has been made by a group of scholars representing the variety of interests reflected in the subseries of the Corpus Christianorum. At the end of the volume an Onomasticon has been added. It gives a complete survey of all the text-editions published to date. This "mini-clavis" will make it easier to find one's way in the library of the Corpus Christianorum.