Integrating receptor interactions and dynamics and Interference with endocrine disruptors in the mechanisms of action of PPAR nuclear receptors

Abstract Peroxisome Proliferator-Activated Receptors (PPARs) form a family of three nuclear receptors regulating important cellular and metabolic functions. PPARs control gene expression by directly binding to target promoters as heterodimers with the Retinoid X Receptor (RXR), and their transcriptional activity is enhanced upon activation by natural or pharmacological ligands. The binding of PPAR/RXR heterodimers on target promoters allows the anchoring of a series of coactivators and corepressors involved in promoter remodeling and the recruitment of the transcription machinery. The transcriptional output finally depends on a complex interplay between (i) the respective expression levels of PPARs, RXRs and of other nuclear receptors competing for DNA binding and RXR recruitment, (ii) the availability and the nature of PPAR and RXR ligands, (iii) the expression levels and the nature of the different coactivators and corepressors and (iv) the sequence and the epigenetic status of the promoter. Understanding how all these factors and signals integrate and fine-tune transcription remains a challenge but is necessary to understand the specificity of the physiological functions regulated by PPARs. The work presented herein focuses on the molecular mechanisms of PPAR action and aims at understanding how the interactions and mobility of the receptor modulate transcription in the physiological context of a living cell: Such observations in vivo rely on the use of engineered fluorescent protein chimeras and require the development and the application of complementary imaging techniques such as Fluorescence Recovery After Photobleaching (FRAP), Fluorescence Resonance Energy Transfer (FRET) and Fluorescence Correlation Spectroscopy (FCS). Using such techniques, PPARs are shown to reside solely in the nucleus where they are constitutively associated with RXR but transcriptional activation by ligand binding -does not promote the formation of sub-nuclear structures as observed with other nuclear receptors. In addition, the engagement of unliganded PPARs in large complexes of cofactors in living cells provides a molecular basis for their ligand-independent activity. Ligand binding reduces receptor diffusion by promoting the recruitment of coactivators which further enlarge the size of PPAR complexes to acquire full transcriptional competence. Using these molecular approaches, we deciphered the molecular mechanisms through which phthalates, a class of pollutants from the plastic industry, interfere with PPARγ signaling. Mono-ethyl-hexyl-phthalate (MEHP) binding induces the recruitment of a specific subset of cofactors and translates into the expression of a specific subset of target genes, the transcriptional output being strongly conditioned by the differentiation status of the cell. This selective PPARγ modulation induces limited adipogenic effects in cellular models while exposure to phthalates in animal models leads to protective effects on glucose tolerance and diet-induced obesity. These results demonstrate that phthalates influence lipid and carbohydrate metabolism through complex mechanisms which most likely involve PPARγ but also probably PPARα and PPAR��, Altogether, the molecular and physiological demonstration of the interference of pollutants with PPAR action outlines an important role of chemical exposure in metabolic regulations. R��sum�� Les PPARs (Peroxisome Proliferator-Activated Receptors) forment une famille de r��cepteurs nucl��aires qui r��gulent des fonctions cellulaires et m��taboliques importantes. Les PPARs contr��lent l'expression des g��nes en se liant directement �� leurs promoteurs sous forme d'h��t��rodim��res avec les r��cepteurs RXR (Retinoid X Receptor), et leur activit�� transcriptionnelle est stimul��e par la liaison de ligands naturels ou pharmacologiques. L'association des h��t��rodim��res PPAR/RXR avec les promoteurs des g��nes cibles permet le recrutement de coactivateurs et de cor��presseurs qui vont permettre le remodelage de la chromatine et le recrutement de la machinerie transcriptionnelle. Les actions transcriptionnelles du r��cepteur d��pendent toutefois d'interactions complexes qui sont r��gul��es par (i) le niveau d'expression des PPARs, des RXRs et d'autres r��cepteurs nucl��aires entrant en comp��tition pour la liaison �� l'ADN et l'association avec RXR, (ii) la disponibilit�� et la nature de ligands de PPAR et de RXR, (iii) les niveaux d'expression et la nature des diff��rents coactivateurs et cor��presseurs et (iv) la s��quence et le marquage ��pig��n��tique des promoteurs. La compr��hension des m��canismes qui permettent d'int��grer ces aspects pour assurer une r��gulation fine de l'activit�� transcriptionnelle est un d��fi qu'il est n��cessaire de relever pour comprendre la sp��cificit�� des fonctions physiologiques r��gul��es par les PPARs. Ce travail concerne l'��tude des m��canismes d'action mol��culaire des PPARs et vise �� mieux comprendre comment les interactions du r��cepteur avec d'autres prot��ines ainsi que la mobilit�� de ce dernier r��gulent son activit�� transcriptionnelle dans le contexte physiologique des cellules vivantes. De telles observations reposent sur l'emploi de prot��ines fusionn��es �� des prot��ines fluorescentes ainsi que sur le d��veloppement et l'utilisation de techniques d'imagerie compl��mentaires telles que le FRAP (Fluorescence Recovery After Photobleaching), le FRET (Fluorescence Resonance Energy Transfer) ou la FCS (Fluorescence Corr��lation Spectroscopy). En appliquant ces m��thodes, nous avons pu montrer que les PPARs r��sident toujours dans le noyau o�� ils sont associ��s de mani��re constitutive �� RXR, mais que l'ajout de ligand n'induit pas la formation de structures sub-nucl��aires comme cela a pu ��tre d��crit pour d'autres r��cepteurs nucl��aires. De plus, les PPARs sont engag��s dans de larges complexes prot��iques de cofacteurs en absence de ligand, ce qui procure une explication mol��culaire �� leur activit�� ligand-ind��pendante. La liaison du ligand r��duit la vitesse de diffusion du r��cepteur en induisant le recrutement de coactivateurs qui augmente encore plus la taille des complexes afin d'acqu��rir un potentiel d'activation maximal. En utilisant ces approches mol��culaires, nous avons pu caract��riser les m��canismes permettant aux phtalates, une classe de polluants provenant de l'industrie plastique, d'interf��rer avec PPARγ. La liaison du mono-ethyl-hexyl-phtalate (NERF) �� PPARγ induit un recrutement s��lectif de cofacteurs, se traduisant par l'induction sp��cifique d'un sous-ensemble de g��nes qui varie en fonction du niveau de diff��rentiation cellulaire. La modulation s��lective de PPARγ par le MEHP provoque une adipogen��se mod��r��e dans des mod��les cellulaires alors que l'exposition de mod��les animaux aux phtalates induit des effets b��n��fiques sur la tol��rance au glucose et sur le d��veloppement de l'ob��sit��. Toutefois, les phtalates ont une action complexe sur le m��tabolisme glucido-lipidique en faisant intervenir PPARγ mais aussi probablement PPARα et PPAR��. Cette d��monstration mol��culaire et physiologique de l'interf��rence des polluants avec les r��cepteurs nucl��aires PPAR souligne un r��le important de l'exposition �� de tels compos��s dans les r��gulations m��taboliques.

Is there an efficient trap or collection method for sampling Anopheles darlingi and other malaria vectors that can describe the essential parameters affecting transmission dynamics as effectively as human landing catches? - A Review

Distribution, abundance, feeding behaviour, host preference, parity status and human-biting and infection rates are among the medical entomological parameters evaluated when determining the vector capacity of mosquito species. To evaluate these parameters, mosquitoes must be collected using an appropriate method. Malaria is primarily transmitted by anthropophilic and synanthropic anophelines. Thus, collection methods must result in the identification of the anthropophilic species and efficiently evaluate the parameters involved in malaria transmission dynamics. Consequently, human landing catches would be the most appropriate method if not for their inherent risk. The choice of alternative anopheline collection methods, such as traps, must consider their effectiveness in reproducing the efficiency of human attraction. Collection methods lure mosquitoes by using a mixture of olfactory, visual and thermal cues. Here, we reviewed, classified and compared the efficiency of anopheline collection methods, with an emphasis on Neotropical anthropophilic species, especially Anopheles darlingi, in distinct malaria epidemiological conditions in Brazil.

Angiostrongylus cantonensis infection in molluscs in the municipality of S��o Gon��alo, a metropolitan area of Rio de Janeiro, Brazil: role of the invasive species Achatina fulica in parasite transmission dynamics

The aim of this study was to analyse the infection dynamics ofAngiostrongylus cantonensisin its possible intermediate hosts over two years in an urban area in the state of Rio de Janeiro where the presence ofA. cantonensis had been previously recorded in molluscs. Four of the seven mollusc species found in the study were exotic.Bradybaena similariswas the most abundant, followed byAchatina fulica, Streptaxissp., Subulina octona, Bulimulus tenuissimus, Sarasinula linguaeformisand Leptinaria unilamellata. Only A. fulicaand B. similariswere parasitised by A. cantonensis and both presented co-infection with other helminths. The prevalence of A. cantonensisin A. fulicawas more than 50% throughout the study. There was an inverse correlation between the population size ofA. fulicaand the prevalence of A. cantonensisand abundance of the latter was negatively related to rainfall. The overall prevalence of A. cantonensisin B. similariswas 24.6%. A. fulicawas the most important intermediary host of A. cantonensisin the studied area andB. similariswas secondary in importance for A. cantonensistransmission dynamics.

Yellow fever impact on brown howler monkeys (Alouatta guariba clamitans) in Argentina: a metamodelling approach based on population viability analysis and epidemiological dynamics

In South America, yellow fever (YF) is an established infectious disease that has been identified outside of its traditional endemic areas, affecting human and nonhuman primate (NHP) populations. In the epidemics that occurred in Argentina between 2007-2009, several outbreaks affecting humans and howler monkeys (Alouatta spp) were reported, highlighting the importance of this disease in the context of conservation medicine and public health policies. Considering the lack of information about YF dynamics in New World NHP, our main goal was to apply modelling tools to better understand YF transmission dynamics among endangered brown howler monkey (Alouatta guariba clamitans) populations in northeastern Argentina. Two complementary modelling tools were used to evaluate brown howler population dynamics in the presence of the disease: Vortex, a stochastic demographic simulation model, and Outbreak, a stochastic disease epidemiology simulation. The baseline model of YF disease epidemiology predicted a very high probability of population decline over the next 100 years. We believe the modelling approach discussed here is a reasonable description of the disease and its effects on the howler monkey population and can be useful to support evidence-based decision-making to guide actions at a regional level.

The NF-κB signaling protein Bcl10 regulates actin dynamics by controlling AP1 and OCRL-bearing vesicles.

The protein Bcl10 contributes to adaptive and innate immunity through the assembly of a signaling complex that plays a key role in antigen receptor and FcR-induced NF-κB activation. Here we demonstrate that Bcl10 has an NF-κB-independent role in actin and membrane remodeling downstream of FcR in human macrophages. Depletion of Bcl10 impaired Rac1 and PI3K activation and led to an abortive phagocytic cup rich in PI(4,5)P(2), Cdc42, and F-actin, which could be rescued with low doses of F-actin depolymerizing drugs. Unexpectedly, we found Bcl10 in a complex with the clathrin adaptors AP1 and EpsinR. In particular, Bcl10 was required to locally deliver the vesicular OCRL phosphatase that regulates PI(4,5)P(2) and F-actin turnover, both crucial for the completion of phagosome closure. Thus, we identify Bcl10 as an early coordinator of NF-κB-mediated immune response with endosomal trafficking and signaling to F-actin remodeling.

The dynamics of Brazilian protozoology over the past century

Brazilian scientists have been contributing to the protozoology field for more than 100 years with important discoveries of new species such asTrypanosoma cruzi and Leishmania spp. In this work, we used a Brazilian thesis database (Coordination for the Improvement of Higher Education Personnel) covering the period from 1987-2011 to identify researchers who contributed substantially to protozoology. We selected 248 advisors by filtering to obtain researchers who supervised at least 10 theses. Based on a computational analysis of the thesis databases, we found students who were supervised by these scientists. A computational procedure was developed to determine the advisors’ scientific ancestors using the Lattes Platform. These analyses provided a list of 1,997 researchers who were inspected through Lattes CV examination and allowed the identification of the pioneers of Brazilian protozoology. Moreover, we investigated the areas in which researchers who earned PhDs in protozoology are now working. We found that 68.4% of them are still in protozoology, while 16.7% have migrated to other fields. We observed that support for protozoology by national or international agencies is clearly correlated with the increase of scientists in the field. Finally, we described the academic genealogy of Brazilian protozoology by formalising the “forest” of Brazilian scientists involved in the study of protozoa and their vectors over the past century.

Two-sided learning in new keynesian models: dynamics, (lack of) convergence and the value of information

This paper investigates the role of learning by private agents and the central bank (two-sided learning) in a New Keynesian framework in which both sides of the economy have asymmetric and imperfect knowledge about the true data generating process. We assume that all agents employ the data that they observe (which may be distinct for different sets of agents) to form beliefs about unknown aspects of the true model of the economy, use their beliefs to decide on actions, and revise these beliefs through a statistical learning algorithm as new information becomes available. We study the short-run dynamics of our model and derive its policy recommendations, particularly with respect to central bank communications. We demonstrate that two-sided learning can generate substantial increases in volatility and persistence, and alter the behavior of the variables in the model in a signifficant way. Our simulations do not converge to a symmetric rational expectations equilibrium and we highlight one source that invalidates the convergence results of Marcet and Sargent (1989). Finally, we identify a novel aspect of central bank communication in models of learning: communication can be harmful if the central bank's model is substantially mis-specified

Social Dynamics in Paper Wasps: The case of nest-drifting in Polistes canadensis

Le passage de la vie solitaire �� la vie sociale repr��sente une des principales transitions ��volutives. La socialit�� a ��volu�� au sein de plusieurs taxons du r��gne animal et notamment chez les insectes sociaux qui ont atteint son niveau le plus ��lev�� : l'eusocialit��. Les colonies d'insectes sociaux se composent d'une reine, qui monopolise la reproduction, et d'ouvri��res, non-reproductrices ou parfois st��riles, qui aident �� ��lever la descendance de la reine. Selon la th��orie de la s��lection de parent��le, les ouvri��res augmentent leur fitness (succ��s reproducteur) non pas �� travers leur propre prog��niture, mais en aidant des individus apparent��s (leur reine) �� produire davantage de descendants. Cette th��orie pr��dit ainsi que les ouvri��res ont un int��r��t �� rester fid��les �� leur nid natal. Toutefois, chez la gu��pe tropicale Polistes canadensis, de nombreuse ouvri��res visitent d'autres nids que leur nid natal : un ph��nom��ne appel�� �� d��rive des ouvri��res ��. Le but de ce doctorat est ainsi de mieux comprendre les m��canismes impliqu��s dans ce comportement particulier des ouvri��res ainsi que ces implications pour la th��orie de la s��lection de parent��le. Nous avons examin�� le comportement de d��rive des ouvri��res �� travers une ��tude des dynamiques sociales chez la gu��pe tropicale P. canadensis. Mes r��sultats montrent que les populations de P. canadensis se composent en diff��rentes agr��gations de nids. Malgr�� de pr��c��dentes suggestions, on n'observe qu'une faible viscosit�� g��n��tique au sein des populations de P. canadensis ��tudi��es. On retrouve toutefois un degr�� d'apparentement entre nids d'une m��me agr��gation. Ceci sugg��re que les ouvri��res d��riveuses sont susceptibles de b��n��ficier de fitness indirect en aidant les nids proches g��ographiquement. De plus, ces ��changes d'ouvri��res ne semblent pas accidentels puisque l'on constate des variations de taux de d��rive et puisque les d��placements observ��s entre nids persistent sur plusieurs p��riodes de temps. La charge de travail, qui correspond aux diff��rences d'effort de fourragement entre nid visit��s et natals, est d��crite dans notre ��tude comme potentiel facteur expliquant le comportement de d��rive des ouvri��res chez P. canadensis. Nos exp��riences de retrait d'ouvri��res et de couvain ont r��v��l��es que les d��riveuses ne semblent pas r��pondre aux changements de besoins en aide des nids visit��s. Les ouvri��res d��riveuses biaisent leur effort en aidant leur propre nid, par lequel elles b��n��ficient le plus en termes de fitness indirect, avant de se consacrer �� tout autre nid. Dans l'ensemble, ces r��sultats sur la d��rive des ouvri��res chez P. canadensis sont coh��rents et sugg��rent que ce comportement est une importante strat��gie de reproduction alternative chez cette esp��ce qui contribue �� la fitness indirecte de ces ouvri��res non-reproductrices. De plus, ce doctorat apporte des informations sur la structure g��n��tique des populations de gu��pes Polistes et d��crit le r��le des ouvri��res inactives. Celles-ci semblent servir de r��serve en ouvri��res apportant du support �� la colonie dans l'��ventualit�� d'une perte d'individus. Plus g��n��ralement, ce travail met l'accent sur l'organisation complexe et l'adaptabilit�� des individus dans les soci��t��s d'insectes. - One major transition in evolution is the shift from solitary to social life. Sociality has evolved in a few taxa of the animal kingdom, most notably in the social insects which have achieved the highest level of sociality: eusociality. Colonies of social insects are formed by a reproductive queen, and many non-reproductive or sterile workers who help raise their mother queen's offspring. Kin selection theory explains worker behaviour in terms of the indirect fitness they gain from raising non-offspring kin. It therefore predicts that workers should stay faithful to their natal nests, to which they are the more related. However, in the tropical paper wasps Polistes canadensis, high levels of nest-drifting, whereby workers spend time on other neighbouring nests, has been reported. This PhD aimed at understanding the mechanisms involved in this peculiar behaviour as well as its implications for kin selection theory. I examined nest-drifting through the study of the social dynamics of the tropical paper wasp P. canadensis. My results showed that populations of this species of paper wasps are composed of different aggregations of nests. The studied populations showed little limited dispersal (viscosity), despite previous suggestion, but nests within these aggregations were more related to each other than nests outside of aggregations. This suggested that drifters may benefit from indirect fitness when helping on neighbouring nests. Drifting was unlikely to be accidental since we found drifting patterns at various rates and consistently over several time periods during monitoring. Workload (differences in colony-level foraging effort) was also a potential factor explaining nest-drifting in P. canadensis. Worker and brood removal experiments revealed that drifters do not respond to any changes in the need for help in the non-natal nests they visit. Drifters thus bias their help in their natal nests, from which they may benefit the most in terms of indirect fitness, before investing in others. Altogether, these results on nest-drifting in P. canadensis are consistent and suggest that nest-drifting is an important alternative reproductive strategy, contributing to the indirect fitness benefits gained by non-reproductive wasps. Additionally, this PhD provides information on the genetic structure of paper wasps' populations and demonstrates the role of inactive or lazy wasps as a "reserve worker force", which provides resilience to the colony in the event of worker mortality. More generally, this work further highlights the complex organization and adaptability of individuals in insect societies.

Robust control of structures subject to uncertain disturbances and actuator dynamics

The objective the present research is try to ���nd some control design strategies, which must be e���ective and closed to the real operation conditions. As a novel contribution to structural control strategies, the theories of Interval Modal Arithmetic, Backstepping Control and QFT (Qualitative Feedback Theory) will be studied. The steps to follow are to develop ���rst new controllers based on the above theories and then to implement the proposed control strategies to di���erent kind of structures. The report is organized as follows. The Chapter 2 presents the state-of-the-art on structural control systems. The chapter 3 presents the most important open problems found in ���eld of structural control. The exploratory work made by the author, research proposal and working plan are given in the Chapter 4

Capitalism in the classroom : the impact of self-enhancement values and normative assessment on student motivation, goals and attitudes towards cheating

Abstract The neo-liberal capitalist ideology has come under heavy fire with anecdotal evidence indicating a link between these same values and unethical behavior. Academic institutions reflect social values and act as socializing agents for the young. Can this explain the high and increasing rates of cheating that currently prevail in education? Our first chapter examines the question of whether self-enhancement values of power and a��hievement, the individual level equivalent of neo-liberal capitalist values, predict positive attitudes towards cheating. Furthermore, we explore the mediating role of motivational factors. Results of four studies reveal that self-enhancement value endorsement predicts the adoption of performance-approach goals, a relationship mediated by introjected regulation, namely desire for social approval and that self-enhancement value endorsement also predicts the condoning of cheating, a relationship mediated by performance-approach goal adoption. However, self-transcendence values prescribed by a normatively salient source have the potential to reduce the link between self-enhancement value endors��ment and attitudes towards cheating. Normative assessment constitutes a key tool used by academic institutions to socialize young people to accept the competitive, meritocratic nature of a soci��ty driven by a neo-liberal capitalist ideology. As such, the manifest function of grades is to motivate students to work hard and to buy into the competing ethos. Does normative assessment fulfill these functions? Our second chapter explores the reward-intrinsic motivation question in the context of grading, arguably a high-stakes reward. In two experiments, the relative capacity of graded high performance as compared to the task autonomy experienced in an ungraded task to predict post-task intrinsic motivation is assessed. Results show that whilst the graded task performance predicts post-task appreciation, it fails to predict ongoing motivation. However, perceived autonomy experienced in non-graded condition, predicts both post-task appreciation and ongoing motivation. Our third chapter asks whether normative assessment inspires the spirit of competition in students. Results of three experimental studies reveal that expectation of a grade for a task, compared to no grade, induces greater adoption of performance-avoidance, but not performance-approach, goals. Experiment 3 provides an explanatory mechanism for this, showing that reduced autonomous motivation experienced in previous graded tasks mediates the relationship between grading and adoption of performance avoidance goals in a subsequent task. The above results, when combined, provide evidence as to the deleterious effects of self enhancement values and the associated practice of normative assessment in school on student motivation, goals and ethics. We conclude by using value and motivation theory to explore solutions to this problem.

Ab initio absorption spectrum of NiO combining molecular dynamics with the embedded cluster approach in a discrete reaction field

We developed a procedure that combines three complementary computational methodologies to improve the theoretical description of the electronic structure of nickel oxide. The starting point is a Car-Parrinello molecular dynamics simulation to incorporate vibrorotational degrees of freedom into the material model. By means ofcomplete active space self-consistent field second-order perturbation theory (CASPT2) calculations on embedded clusters extracted from the resulting trajectory, we describe localized spectroscopic phenomena on NiO with an efficient treatment of electron correlation. The inclusion of thermal motion into the theoretical description allowsus to study electronic transitions that, otherwise, would be dipole forbidden in the ideal structure and results in a natural reproduction of the band broadening. Moreover, we improved the embedded cluster model by incorporating self-consistently at the complete active space self-consistent field (CASSCF) level a discrete (or direct) reaction field (DRF) in the cluster surroundings. The DRF approach offers an efficient treatment ofelectric response effects of the crystalline embedding to the electronic transitions localized in the cluster. We offer accurate theoretical estimates of the absorption spectrum and the density of states around the Fermi level of NiO, and a comprehensive explanation of the source of the broadening and the relaxation of the charge transferstates due to the adaptation of the environment

An integrated approach for the assessment of HAB dynamics in two NW Mediterranean bays from a GEOHAB perspective

Alfacs and Fangar Bay in the Ebro Delta, NW Mediterranean are the major sites in Catalonia for shellfish cultivation. These bays are subject to occasional closures in shellfish harvesting due to the presence of phycotoxins. Fish kills have also been associated with harmful algal blooms. The comparison of phytoplankton dynamics in both bays offers the opportunity to reveal differences in bloom patterns of species known to be harmful for the ecosystem and aquaculture activities. Field research is underway under the GEOHAB framework within the Core Research Project on HABs in Fjords and Coastal Embayments. The overall objective of this study is to improve our understanding of HAB biogeographical patterns, and key elements driving bloom dynamics in time and space within these semi-constrained embayments. Via the comparative approach we aim to improve the prediction for monitoring purposes, with a focus on Karlodinium spp. associated with massive kills of aquaculture species. This objective is addressed by incorporating long-term time series of phytoplankton identification and enumeration with the first results of recent field work in both bays. The latter includes the application of optical sensors, to yield a complementary view with enhanced spatial and temporal resolution of bloom phenomena.

Avalanche dynamics of fiber bundle models

We present a detailed analytical and numerical study of the avalanche distributions of the continuous damage fiber bundle model CDFBM . Linearly elastic fibers undergo a series of partial failure events which give rise to a gradual degradation of their stiffness. We show that the model reproduces a wide range of mechanical behaviors. We find that macroscopic hardening and plastic responses are characterized by avalanche distributions, which exhibit an algebraic decay with exponents between 5/2 and 2 different from those observed in mean-field fiber bundle models. We also derive analytically the phase diagram of a family of CDFBM which covers a large variety of potential avalanche size distributions. Our results provide a unified view of the statistics of breaking avalanches in fiber bundle models

Implementaci�� d'una interf��cie per al control de tra��abilitat en el ERP Microsoft Dynamics AX

Implementaci�� d'una interf��cie per a dur un control de tra��abilitat de diversos productes, mitjan��ant el codi d'article i el n��mero de lot. Obtenint aix�� la hist��ria d'aquests, ��s a dir, obtenint informaci�� sobre l'origen, el dest�� i els processos de transformaci�� que han sofert.