969 resultados para on-disk data layout
Resumo:
The aim of the project was to gauge the extent to which the so-called ‘Barcelona Model’ of urban transformation has been ‘exported’ to Britain and whether Barcelona has learned from British cities. We engage with the literature on successive British governments’ strategies for cities, focused on collecting data on contemporary policy initiatives and debates in the UK, did interviews in Manchester, London Barcelona and participated in the official visit of Leeds to Barcelona in March. Our research findings to date suggest that there is a good deal of mobility and interaction between Barcelona and the UK. However, it is by no means certain that this has resulted in definite instances of policy transfer. While the ‘Barcelona model’ has indeed featured in oficial discourse on urban regeneration in the UK, it does not appear to be the preferred best practice ‘model’ – other North American and European cities figure discursively as much, if not more. Where Barcelona does feature in official discourse, it is usually as an example of good design and an appealing urban aesthetic, rather than in terms of economic or social policy best practice. Our research suggests that the Barcelona model is seen as non-transferable to the UK due to the relatively more centralised governance structure therein.In contrast, evidence collected suggests that the Barcelona model is not influenced by UK British cities experiences but there is small evidence of being influenced by UK-based professionals.
Resumo:
L’objectiu del treball és ajudar a la descripció del fenomen del canvi en els itineraris formatius superiors dels estudiants. L’anàlisi es realitza a partir de dades empíriques generades a la UAB durant l’any 2012 i en base als factors contextuals – socio-demogràfics, de perfil i context de l’estudiant – i motivacionals – de vocació acadèmica, vocació laboral, resultats acadèmics, condicions facilitadores, condicions d’empleabilitat, condicions econòmiques, influència de les amistats, estratègies adaptatives o d’oportunitat – que influeixen en les decisions de canvi dels estudiants. En les conclusions es reflexiona sobre les polítiques orientades a mantenir l’equitat en l’accés i en la permanència dels estudiants.
Resumo:
Models incorporating more realistic models of customer behavior, as customers choosing froman offer set, have recently become popular in assortment optimization and revenue management.The dynamic program for these models is intractable and approximated by a deterministiclinear program called the CDLP which has an exponential number of columns. However, whenthe segment consideration sets overlap, the CDLP is difficult to solve. Column generationhas been proposed but finding an entering column has been shown to be NP-hard. In thispaper we propose a new approach called SDCP to solving CDLP based on segments and theirconsideration sets. SDCP is a relaxation of CDLP and hence forms a looser upper bound onthe dynamic program but coincides with CDLP for the case of non-overlapping segments. Ifthe number of elements in a consideration set for a segment is not very large (SDCP) can beapplied to any discrete-choice model of consumer behavior. We tighten the SDCP bound by(i) simulations, called the randomized concave programming (RCP) method, and (ii) by addingcuts to a recent compact formulation of the problem for a latent multinomial-choice model ofdemand (SBLP+). This latter approach turns out to be very effective, essentially obtainingCDLP value, and excellent revenue performance in simulations, even for overlapping segments.By formulating the problem as a separation problem, we give insight into why CDLP is easyfor the MNL with non-overlapping considerations sets and why generalizations of MNL posedifficulties. We perform numerical simulations to determine the revenue performance of all themethods on reference data sets in the literature.
Resumo:
A cidade foi sendo perspetivada como um lugar masculino em que as mulheres (e, em particular, as mulheres imigrantes) não eram cidadãs plenas no sentido em que não adquiriram o acesso integral e livre às ruas e sobreviveram nos interstícios da cidade. Apesar de todas as conquistas das mulheres e do aparente cosmopolitismo das cidades europeias, as cidades continuam a ser espaços genderizados, espaços de conflito e de discriminação, contextos plenos de ameaças e interdições. Neste artigo apresentaremos algumas reflexões sobre a forma como as mulheres imigrantes brasileiras, cabo-verdianas e ucranianas se relacionam com o espaço - cidade de Lisboa - com base nos dados do projeto de investigação da autora financiado pelo Observatório da Imigração “Mulheres imigrantes em Portugal. Memórias, dificuldades de integração e projetos de vida”.
Resumo:
A Method is offered that makes it possible to apply generalized canonicalcorrelations analysis (CANCOR) to two or more matrices of different row and column order. The new method optimizes the generalized canonical correlationanalysis objective by considering only the observed values. This is achieved byemploying selection matrices. We present and discuss fit measures to assessthe quality of the solutions. In a simulation study we assess the performance of our new method and compare it to an existing procedure called GENCOM,proposed by Green and Carroll. We find that our new method outperforms the GENCOM algorithm both with respect to model fit and recovery of the truestructure. Moreover, as our new method does not require any type of iteration itis easier to implement and requires less computation. We illustrate the methodby means of an example concerning the relative positions of the political parties inthe Netherlands based on provincial data.
Resumo:
We present an exact test for whether two random variables that have known bounds on their support are negatively correlated. The alternative hypothesis is that they are not negatively correlated. No assumptions are made on the underlying distributions. We show by example that the Spearman rank correlation test as the competing exact test of correlation in nonparametric settings rests on an additional assumption on the data generating process without which it is not valid as a test for correlation.We then show how to test for the significance of the slope in a linear regression analysis that invovles a single independent variable and where outcomes of the dependent variable belong to a known bounded set.
Resumo:
We propose an alternative method for measuring intergenerational mobility. Measurements obtained fromtraditional methods (based on panel data) are scarce, difficult to compare across countries and almost impossible to get across time. In particular, this means that we do not know how intergenerational mobility is correlated with growth, income or the degree of inequality.Our proposal is to measure the informative content of surnames in one census. The more information thesurname has on the income of an individual, the more important is her background in determining her outcomes; and thus, the less mobility there is.The reason is that surnames provide information about family relationships because the distribution ofsurnames is necessarily very skewed. A large percentage of the population is bound to have a very unfrequent surname. For them the partition generated by surnames is very informative on family linkages.First, we develop a model whose endogenous variable is the joint distribution of surnames and income.There, we explore the relationship between mobility and the informative content of surnames. We allow for assortative mating to be a determinant of both.Second, we use our methodology to show that in large Spanish region the informative content of surnamesis large and consistent with the model. We also show that it has increased over time, indicating a substantial drop in the degree of mobility. Finally, using the peculiarities of the Spanish surname convention we show that the degree of assortative mating has also increased over time, in such a manner that might explain the decrease in mobility observed.Our method allows us to provide measures of mobility comparable across time. It should also allow us tostudy other issues related to inheritance.
Resumo:
Pineus boerneri Annand, 1928 (Hemiptera, Adelgidae) _ a new species to Brazil: morphology of eggs, nymphs and adults. Pineus boerneri represents the first Adelgidae species recorded in Brazil. This aphid species forms extensive colonies on branches and trunk of Pinus spp., with apterous oviparous females, eggs and nymphs covered with white wax. The aim of this research is to study the morphology of eggs, nymphs, and adults to provide useful data for species identification in order to solve taxonomic issues. The study was based on morphometric data and optical and scanning electron microscopy images. First instar nymphs are active and can be easily distinguished from the others by their elongate minute yellowish body; well developed legs bearing a pair of sensorial setae at the apex of the second tarsomere; and antenna with three segments with a large rhinarium and distinct apical setae on the last segment. From the second to the fourth instar, nymphs are sessile, with round red body; they loose the third antennal segment and its sensorial structures, as well as the setae on the second tarsomere. The oviparous female is reddish-brown, with round body with about 0.76 mm diameter; legs reduced; antennae one-segmented; ovipositor distinct; numerous wax glands are present, mainly on the head. Accurate characterization of the species and distinction of the nymphal instars of P. boerneri were made possible by canonical analysis of morphometric data and morphological characters.
Resumo:
In this article we show that in the presence of trading constraints, such as short sale constraints, the standard definition of a Rational Expectations Equilibrium allows for equilibrium prices that reveal information unknown to any active trader in the market. We propose a new definition of the Rational Expectations Equilibrium that incorporates a stronger measurability condition than measurability with respect to the join of the information sets of the agents and give an example of non-existence of equilibrium. The example is robust to perturbations on the data of the economy and the introduction of new assets.
Resumo:
When did overseas trade start to matter for living standards? Traditional real-wage indices suggest that living standards in Europe stagnated before 1800. In this paper, we argue thatwelfare rose substantially, but surreptitiously, because of an influx of new goods as a result ofoverseas trade. Colonial luxuries such as tea, coffee, and sugar transformed European diets afterthe discovery of America and the rounding of the Cape of Good Hope. These goods became household items in many countries by the end of the 18th century. We use three different methodsto calculate welfare gains based on price data and the rate of adoption of these new colonialgoods. Our results suggest that by 1800, the average Englishman would have been willing to forego 10% or more of his income in order to maintain access to sugar and tea alone. These findings are robust to a wide range of alternative assumptions, data series, and valuation methods.
Resumo:
Designing an efficient sampling strategy is of crucial importance for habitat suitability modelling. This paper compares four such strategies, namely, 'random', 'regular', 'proportional-stratified' and 'equal -stratified'- to investigate (1) how they affect prediction accuracy and (2) how sensitive they are to sample size. In order to compare them, a virtual species approach (Ecol. Model. 145 (2001) 111) in a real landscape, based on reliable data, was chosen. The distribution of the virtual species was sampled 300 times using each of the four strategies in four sample sizes. The sampled data were then fed into a GLM to make two types of prediction: (1) habitat suitability and (2) presence/ absence. Comparing the predictions to the known distribution of the virtual species allows model accuracy to be assessed. Habitat suitability predictions were assessed by Pearson's correlation coefficient and presence/absence predictions by Cohen's K agreement coefficient. The results show the 'regular' and 'equal-stratified' sampling strategies to be the most accurate and most robust. We propose the following characteristics to improve sample design: (1) increase sample size, (2) prefer systematic to random sampling and (3) include environmental information in the design'
Resumo:
El calamar gigante Dosidicus gigas (d'Orbigny, 1835) es un depredador importante en el ecosistema del Perú. Se postula que el papel del calamar gigante varía teniendo en cuenta la talla, tiempo, hora, temperatura y distribución espacial. Para comprobar esta hipótesis se aplicó un modelo aditivo generalizado (GAM) en datos biológicos de alimentación de 4178 calamares gigantes capturados por la flota industrial pesquera a lo largo del litoral peruano (3ºS a 18ºS) desde 2 a 299 millas náuticas (mn) de distancia a la costa desde el año 2004 a 2009 realizados por el Laboratorio de Ecología Trófica del Instituto del Mar del Perú (IMARPE). La talla de los calamares estudiados fluctuó entre 14 y 112 cm de longitud de manto (LM). En total 43 item-presa fueron registrados, los grupos más importantes fueron los cefalópodos (Dosidicus gigas), Teleosteii (Photichthyidae, Myctophidae y Nomeidae) y Malacostraca crustáceos (Euphausiidae). Las presas principales fueron D. gigas (indicando canibalismo) en términos gravimétricos (% W=35.4), los otros cephalopodos en frecuencia de ocurrencia (FO=14.4), y los eufáusidos en términos de abundancia relativa (% N=62.2). Estos resultados reflejan una alta variabilidad de la dieta, y un espectro trófico similar en comparación con otras latitudes en ambos hemisferios (México y Chile). Los modelos GAM muestran que todas las variables predictoras fueron significativas en relación a la variable respuesta llenura estomacal (p <0.0001). La llenura estomacal fue mayor en los individuos juveniles, también durante la noche hubo mayor consumo, mientras no se reflejaron tendencias en la alimentación con relación a la temperatura superficial del mar (TSM), pero espacialmente se observan cambios en la dieta, aumentando el porcentaje de llenura a medida que esta especie se aleja de la costa. Por lo tanto se concluye que la dieta del calamar gigante depende de la talla y su distribución espacio-temporal.
Resumo:
In this study we have characterized intra-patient length polymorphism in V4 by cloning and sequencing a C2-C4 fragment from HIV plasma RNA in patients at different stages of HIV disease. Clonal analysis of clade B, G, and CRF02 isolates during early infection shows extensive intra-patient V4 variability, due to the presence of indel-associated polymorphism. Indels, coupled to amino acid substitution events, affect the number and distribution of potential N-glycosylation sites, resulting in the coexistence, within the same patient, of V4 subsets, each characterized by different sizes, amino acid sequences, and potential N-glycosylation patterns. In contrast, V3 appears to be relatively homogeneous, with similar V3 associated to significantly different V4 within the same clinical specimen. Based on these data, we propose that during early chronic infection V4 is present as a highly divergent quasispecies, enabling the virus to adopt different conformational structures according to immune constrains and other selective pressures
Resumo:
TEXTABLE est un nouvel outil open source de programmation visuelle pour l'analyse de données textuelles. Les implications de la conception de ce logiciel du point de vue de l'interopérabilité et de la flexibilité sont abordées, ainsi que la question que son adéquation pour un usage pédagogique. Une brève introduction aux principes de la programmation visuelle pour l'analyse de données textuelles est également proposée.
Resumo:
Background: Acute Myeloid Leukemia (AML) in the elderly is notoriously difficult to treat and has a low remission rate with very few long term survivors when using standard treatment approaches. Azacytidine, a hypomethylating agent, has been shown to induce remission and prolong survival in patients with myelodysplastic syndromes; studying this approach to patients with AML is therefore warranted. We present results of an ongoing phase II trial treating elderly or frail AML patients with Azacytidine. Methods: AML elderly or frail patients, and therefore unfit for an intensive chemotherapy regimens, with a WHO performance status 3 were considered for this trial. Trial therapy consisted of 100mg/m2 of Azacytidine injected subcutaneously on 5 consecutive days every 28 days up to 6 cycles, stopping at 6 months if no hematological improvement achieved, or earlier in the case of progression or complications. Treatment was continued beyond 6 months in responding patients. Trial therapy was considered uninteresting if the response rate (CR + PR) within 6 months of therapy initiation was 15% or less and promising if 34% or more. Using the exact single-stage phase II design by A'Hern with a 5% significance level and 90% power, 43 patients were required: If 10 or fewer achieved a response within 6 months the trial therapy should not be considered for further investigation in its current format for this indication and patient population. Results: Between September 2008 and January 2010, 45 evaluable patients across 10 Swiss centers were accrued with a median follow-up of 7 months (range: 0 - 13). 27 (60%) were male, median age was 74 (range: 55 - 86) years and 35 (78.8%) had performance status 0-1. Patients had been excluded from more intensive chemotherapy regimens because of age (n = 37) or due to comorbidities or patient refusal (n=8). Five patients had therapy related AML. Patients received a median of 3 (range: 1 - 10) cycles. Treatment was stopped for not achieving a response by the 6th cycle in 2 patients and earlier in 26 patients (for disease progression in 5, toxicity in 3, patient refusal in 2, recurrent infections in 1, and death in 8). Seventeen patients remain on therapy. The median time spent in the hospital was 12 days (1 - 30) in 24/38 patients hospitalized during the first treatment cycle and 13 days (2 - 28) in 15/31 patients hospitalized during subsequent cycles. Adverse events of grade III or higher most frequently reported were constitutional or hematologic, i.e. fatigue in 5, febrile neutropenia in 8, infections in 6, dyspnea in 6, anemia in 3, neutropenia in 12 and thrombocytopenia in 10, hemorrhage in 2 and retinal detachment in 5. Based on available data on 38 patients, CR/CRi or hematologic improvement or stable disease within 6 months of trial registration was observed in a proportion of patients. Final and mature data, determining whether the predefined proportion of responding patients has been reached or not, will be presented at the conference. Up to now there were a total of 26 deaths. Median overall survival time was 5.7 months (95% CI: 3.1, 8.7). Conclusions: The current results of this slightly modified Azacytidine schedule demonstrate a feasible new therapy option for elderly or frail AML patients in an outpatient setting with moderate, mainly hematologic toxicity.