1,353 research outputs found
A Comparison of Machine-Learning Methods to Select Socioeconomic Indicators in Cultural Landscapes
Cultural landscapes are regarded to be complex socioecological systems that originated as a result of the interaction between humanity and nature across time. Cultural landscapes present complex-system properties, including nonlinear dynamics among their components. There is a close relationship between socioeconomy and landscape in cultural landscapes, so that changes in the socioeconomic dynamic have an effect on the structure and functionality of the landscape. Several numerical analyses have been carried out to study this relationship, with linear regression models being widely used. However, cultural landscapes comprise a considerable amount of elements and processes, whose interactions might not be properly captured by a linear model. In recent years, machine-learning techniques have increasingly been applied to the field of ecology to solve regression tasks. These techniques provide sound methods and algorithms for dealing with complex systems under uncertainty. The term ‘machine learning’ includes a wide variety of methods to learn models from data. In this paper, we study the relationship between socioeconomy and cultural landscape (in Andalusia, Spain) at two different spatial scales aiming at comparing different regression models from a predictive-accuracy point of view, including model trees and neural or Bayesian networks
The Role of Cultural Landscapes in the Delivery of Provisioning Ecosystem Services in Protected Areas
The aim of this paper is to assess and highlight the significance of cultural landscapes in protected areas, considering both biodiversity and the delivery of provisioning ecosystem services. In order to do that, we analyzed 26 protected areas in Andalusia (Spain), all of them Natural or National Parks, regarding some of their ecosystem services (agriculture, livestock grazing, microclimate regulation, environmental education and tourism) and diversity of the four terrestrial vertebrate classes: amphibians, reptiles, mammals, and birds. A cluster analysis was also run in order to group the 26 protected areas according to their dominant landscape. The results show that protected areas dominated by dehesa (a heterogeneous system containing different states of ecological maturity), or having strong presence of olive groves, present a larger area of delivery of provisioning ecosystem services, on average. These cultural landscapes play an essential role not only for biodiversity conservation but also as providers of provisioning ecosystem services
Analyzing Uncertainty in Complex Socio-Ecological Networks
Socio-ecological systems are recognized as complex adaptive systems whose multiple interactions might change as a response to external or internal changes. Due to its complexity, the behavior of the system is often uncertain. Bayesian networks provide a sound approach for handling complex domains endowed with uncertainty. The aim of this paper is to analyze the impact of the Bayesian network structure on the uncertainty of the model, expressed as the Shannon entropy. In particular, three strategies for model structure have been followed: naive Bayes (NB), tree augmented network (TAN) and network with unrestricted structure (GSS). Using these network structures, two experiments are carried out: (1) the impact of the Bayesian network structure on the entropy of the model is assessed and (2) the entropy of the posterior distribution of the class variable obtained from the different structures is compared. The results show that GSS constantly outperforms both NB and TAN when it comes to evaluating the uncertainty of the entire model. On the other hand, NB and TAN yielded lower entropy values of the posterior distribution of the class variable, which makes them preferable when the goal is to carry out predictions
Wt1 is involved in pancreas development and adult pancreatic homeostasis
The embryonic mesothelium lining the visceral organs gives rise to mesenchymal cells through a localized epithelial-mesenchymal transition (EMT). This has been extensively studied in some cases, such as the heart, where the epicardium gives rise to epicardial-derived cells that contribute to the cardiac vascular and connective tissues. In other organs, such as the lungs, liver and gut, the developmental fate of the mesothelial-derived mesenchyme and their importance for visceral morphogenesis has also been demonstrated (reviewed in Ariza et al., Dev Dyn, 2016, 245:307-22).
Hepatic stellate cells (HSC) are located in the perisinusoidal space of the liver. It has been described that cells derived from the liver mesothelium through an EMT contributes to the HSC population and also to the sinusoidal endothelium during development (IJpenberg et al. Dev Biol, 2007, 312: 157–170; Asahina et al., Hepatology, 2011, 53:983-95). Thus, we checked is a similar developmental origin accounts for pancreatic stellate cells (PSC), a population of pancreatic stromal cells that share many features with HSC. In normal adult pancreas, PSC are quiescent, star-shaped cells with a periacinar distribution. When activated by profibrogenic stimuli such as inflammatory cytokines or oxidative stress, PSC transform into myofibroblast-like cells. Thus, PSC are the major source of extracellular matrix in the adult pancreas, but their embryonic origin remains unknown.
The Wilms’ tumor suppressor gene (Wt1) is highly expressed in the embryonic mesothelium. For this reason, we have used two lines of transgenic mice for lineage tracing of mesothelial-derived cells, systemic (Wt1Cre; R26REYFP), tamoxifen-inducible (Wt1ERT2; R26REYFP) and we have also used the inducible driver for conditional deletion of Wt1 (Wt1ERT2; Wt1 flox) in adult mice.
Our results confirm that WT1 protein is only expressed in the mesothelium of the developing pancreas, allowing for reliable tracing of the mesothelial-derived cells. During the early stages of pancreas morphogenesis, its mesothelium shows the typical features of EMT. Mesothelial-derived cells, identified by constitutive YFP expression, differentiate into a major part of the PSCs and also contribute to other connective and vascular cell type, including endothelium. Thus, mesothelial-derived cells originated by EMT seem to constitute an important subpopulation of mesodermal cells during pancreas development, contributing to its morphogenesis.
On the other hand, systemic deletion of Wt1 in adult mice causes a severe atrophy of the pancreas, although this factor is only expressed in the pancreatic mesothelium. In addition, we have observed that adult PSC express Wt1 in the caerulein-induced pancreatitis model. Our results suggest that: 1) normal pancreatic function is maintained by a Wt1-dependent signaling mechanism acting from the mesothelium and 2) Wt1 plays a role in PSC activation in adult mice. These observations point to a relevant function of the Wt1 gene in pancreatic development and function.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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Translating Hiromi Kawakami’s “Tread on a snake”
textThis report includes my translation of the short story “Tread on a Snake” (Hebi o Fumu) by Kawakami Hiromi, which is presented here as a significant contribution to modern Japanese literature in translation. The story received the prestigious Akutagawa Prize in 1996, although support for it was not unanimous as seen in my translation of the judges’ comments offered here as well. Following the translation of the story itself is an essay that discusses my personal experiences translating the story. I discuss elements that may be unique to the experience of translating Kawakami’s works, but also many that are applicable more broadly to issues of translation that go beyond her works and even Japanese literature as well. Challenges included maintaining the author’s tone and voice, the appropriate use of notes to provide cultural background, and the deliberate use of non-translated terms in a translation.Asian Studie
Penalized functional spatial regression
This paper is focus on spatial functional variables whose observa- tions are realizations of a spatio-temporal functional process. In this context, a new smoothing method for functional data presenting spa- tial dependence is proposed. This approach is based on a P-spline estimation of a functional spatial regression model. As alternative to other geostatistical smoothing methods (kriging and kernel smooth- ing, among others), the proposed P-spline approach can be used to estimate the functional form of a set of sample paths observed only at a finite set of time points, and also to predict the corresponding func- tional variable at a new location within the plane of study. In order to test the good performance of the proposed method, two simulation studies and an application with real data will be developed and the results will be compared with functional kriging.Financial support from the project P11-FQM-8068 from Consejería de Innovación, Ciencia y Empresa. Junta de Andalucía, Spain and the projects MTM2013-47929-P and MTM 2011-28285-C02-C2 from Secretaría de Estado Investigación, Desarrollo e
Innovación, Ministerio de Economía y Competitividad, Spain
Las mujeres en la imprenta catalana de los siglos XVI al XVIII
Treballs Finals de Grau en Història, Facultat de Geografia i Història, Universitat de Barcelona, Curs: 2016-2017, Tutor: Jaume Dantí i Riu[spa] A mediados del siglo XV se introdujo en España una nueva técnica en el arte de la edición de libros: la imprenta. Desde entonces, y a lo largo de toda la Edad Moderna, una de las zonas con destacada producción de textos impresos fue Cataluña, donde surgieron importantes familias de impresores y libreros como los Cormellas, los Martí o los Piferrer. Dentro de este gremio, eminentemente familiar, las mujeres también participaron desempeñando diversas tareas, -de forma discreta en los siglos XVI y XVII, pero de manera más activa en el siglo XVIII-. En este sentido, el presente trabajo pretende ser un estado de la cuestión que nos permita conocer, a través de diferentes casos, el papel real que las impresoras y libreras tuvieron en el desarrollo de este negocio y, por tanto, en el desarrollo de la imprenta y la cultura en la Cataluña de los siglos XVI al XVIII.[eng] In the middle of the fifteenth century a new technique was introduced in Spain in the art of book publishing: the printing press. Since then, and throughout the Modern Age, Catalonia was one of the areas with a big production of printed texts, where important families of printers and booksellers like Cormellas, Martí or Piferrer emerged. Within this eminently familiar guild, women also participated in various task, -discreetly in the sixteenth and seventeenth centuries, but more actively in the eighteenth century-. For this reason, the present work pretends to be a state of the issue that allow us to know, though different cases, the real role that women had in the development of this business and in the development of the printing and culture in Catalonia from the sixteenth to the eighteenth centuries
Basis expansion approaches for functional analysis of variance with repeated measures
The methodological contribution in this paper is motivated by biomechanical
studies where data characterizing human movement are waveform curves
representing joint measures such as flexion angles, velocity, acceleration, and
so on. In many cases the aim consists of detecting differences in gait patterns
when several independent samples of subjects walk or run under different
conditions (repeated measures). Classic kinematic studies often analyse
discrete summaries of the sample curves discarding important information and
providing biased results. As the sample data are obviously curves, a Functional
Data Analysis approach is proposed to solve the problem of testing the equality
of the mean curves of a functional variable observed on several independent
groups under different treatments or time periods. A novel approach for
Functional Analysis of Variance (FANOVA) for repeated measures that takes into
account the complete curves is introduced. By assuming a basis expansion for
each sample curve, two-way FANOVA problem is reduced to Multivariate ANOVA for
the multivariate response of basis coefficients. Then, two different approaches
for MANOVA with repeated measures are considered. Besides, an extensive
simulation study is developed to check their performance. Finally, two
applications with gait data are developed
Comparative study of different B-spline approaches for functional data
The sample observations of a functional variable are functions that come from the
observation of a statistical variable in a continuous argument that in most cases is the
time. But in practice, the sample functions are observed in a finite set of points. Then, the
first step in functional data analysis is to reconstruct the functional form of sample curves
from discrete observations. The sample curves are usually represented in terms of basis
functions and the basis coefficients are fitted by interpolation, when data are observed
without error, or by least squares approximation, in the other case. The main purpose of
this paper is to compare three different approaches for estimating smooth sample curves
observed with error in terms of B-spline basis: regression splines (non-penalized least
squares approximation), smoothing splines (continuous roughness penalty) and P-splines
(discrete roughness penalty). The performance of these spline smoothing approaches is
studied via a simulation study and several applications with real data. Cross-validation and
generalized cross-validation are adapted to select a common smoothing parameter for all
sample curves with the roughness penalty approaches. From the results, it is concluded
that both penalized approaches drastically reduced the mean squared errors with respect
to the original smooth sample curves with P-splines giving the best approximations with
less computational cost.Project MTM2010-20502 from Dirección General de Investigación, Ministerio de Educación y Ciencia SpainProject P11-FQM-8068 from Consejería de Innovación, Ciencia y Empresa. Junta de Andalucía, Spai
Yra1-bound RNA–DNA hybrids cause orientation-independent transcription– replication collisions and telomere instability
R loops are an important source of genome instability, largely due to their negative impact on replication progression. Yra1/ALY is an abundant RNA-binding factor conserved from yeast to humans and required for mRNA export, but its excess causes lethality and genome instability. Here, we show that, in addition to ssDNA and ssRNA, Yra1 binds RNA–DNA hybrids in vitro and, when artificially overexpressed, can be recruited to chromatin in an RNA– DNA hybrid-dependent manner, stabilizing R loops and converting them into replication obstacles in vivo. Importantly, an excess of Yra1 increases R-loop-mediated genome instability caused by transcription–replication collisions regardless of whether they are codirectional or head-on. It also induces telomere shortening in telomerase-negative cells and accelerates senescence, consistent with a defect in telomere replication. Our results indicate that RNA–DNA hybrids form transiently in cells regardless of replication and, after stabilization by excess Yra1, compromise genome integrity, in agreement with a two-step model of R-loop-mediated genome instability. This work opens new perspectives to understand transcription-associated genome instability in repair-deficient cells, including tumoral cells.European Research Council ERC2014 AdG669898 TARLOOPMinisterio de Economía y Competitividad BFU2016-75058-PJunta de Andalucía PA12- BIO123
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