Alienígenas na sala: o que fazer com espécies exóticas em trabalhos de taxonomia, florística e fitossociologia?

A presença cada vez mais disseminada de organismos exóticos (muitos dos quais se tornam invasores) nas diferentes regiões do planeta levou ao surgimento de uma linha de pesquisa na ecologia voltada às invasões biológicas. E para permitir a comunicação entre autores também foi desenvolvido um arcabouço terminológico. Mas, apesar disso, a terminologia relativa às bioinvasões tem sido ignorada por boa parte dos botânicos no Brasil. Há uma boa dose de confusão entre botânicos sobre o que seja uma espécie exótica, naturalizada, invasora, daninha e ruderal, levando ao uso inconsistente da terminologia. Além disso, diferentes autores têm adotado posturas praticamente opostas ao lidar com espécies exóticas em suas áreas de estudo, seja na preparação de tratamentos taxonômicos, seja na publicação de levantamentos florísticos e fitossociológicos. Enquanto alguns pesquisadores incluem em floras mesmo espécies cultivadas que não se reproduzem, outros excluem plantas invasoras comuns e conspícuas. Nós apresentamos aqui, em português, os principais conceitos relativos ao tema da bioinvasão e chamamos a atenção dos autores brasileiros para a necessidade de utilizar de modo consistente o arcabouço terminológico já existente na literatura. Também propomos a adoção de rótulos claros para informar quais espécies são exóticas na área estudada, diferenciando-as das nativas, e sugerimos critérios para ajudar botânicos a decidirem quando uma planta exótica deve ou não ser incluída em tratamentos taxonômicos ou levantamentos de florística.

OPTIMIZATION AND CONTROL OF A CONTINUOUS POLYMERIZATION REACTOR

This work studies the optimization and control of a styrene polymerization reactor. The proposed strategy deals with the case where, because of market conditions and equipment deterioration, the optimal operating point of the continuous reactor is modified significantly along the operation time and the control system has to search for this optimum point, besides keeping the reactor system stable at any possible point. The approach considered here consists of three layers: the Real Time Optimization (RTO), the Model Predictive Control (MPC) and a Target Calculation (TC) that coordinates the communication between the two other layers and guarantees the stability of the whole structure. The proposed algorithm is simulated with the phenomenological model of a styrene polymerization reactor, which has been widely used as a benchmark for process control. The complete optimization structure for the styrene process including disturbances rejection is developed. The simulation results show the robustness of the proposed strategy and the capability to deal with disturbances while the economic objective is optimized.

Mixed-valence state of symmetric diruthenium complexes: synthesis, characterization, and electron transfer investigation

Complexes of the type {[(pyS)Ru(NH3)(4)](2)-mu-L}(n), where pyS = 4-mercaptopyridine, L = 4,4'-dithiodipyridine (pySSpy), pyrazine (pz) and 1,4-dicyanobenzene (DCB), and n = +4 and +5 for fully reduced and mixed-valence complexes, respectively, were synthesized and characterized. Electrochemical data showed that there is electron communication between the metal centers with comproportionation constants of 33.2, 1.30 x 10(8) and 5.56 x 10(5) for L = pySSpy, pz and DCB, respectively. It was also observed that the electronic coupling between the metal centers is affected by the p-back-bonding interaction toward the pyS ligand. Raman spectroscopy showed a dependence of the intensity of the vibrational modes on the exciting radiations giving support to the assignments of the electronic transitions. The degree of electron communication between the metal centers through the bridging ligands suggests that these systems can be molecular wire materials.

Analysis of the biofilm proteome of Xylella fastidiosa

Abstract Background Xylella fastidiosa is limited to the xylem of the plant host and the foregut of insect vectors (sharpshooters). The mechanism of pathogenicity of this bacterium differs from other plant pathogens, since it does not present typical genes that confer specific interactions between plant and pathogens (avr and/or hrp). The bacterium is injected directly into the xylem vessels where it adheres and colonizes. The whole process leads to the formation of biofilms, which are considered the main mechanism of pathogenicity. Cells in biofilms are metabolically and phenotypically different from their planktonic condition. The mature biofilm stage (phase of higher cell density) presents high virulence and resistance to toxic substances such as antibiotics and detergents. Here we performed proteomic analysis of proteins expressed exclusively in the mature biofilm of X. fastidiosa strain 9a5c, in comparison to planktonic growth condition. Results We found a total of 456 proteins expressed in the biofilm condition, which correspond to approximately 10% of total protein in the genome. The biofilm showed 37% (or 144 proteins) different protein than we found in the planktonic growth condition. The large difference in protein pattern in the biofilm condition may be responsible for the physiological changes of the cells in the biofilm of X. fastidiosa. Mass spectrometry was used to identify these proteins, while real-time quantitative polymerase chain reaction monitored expression of genes encoding them. Most of proteins expressed in the mature biofilm growth were associated with metabolism, adhesion, pathogenicity and stress conditions. Even though the biofilm cells in this work were not submitted to any stress condition, some stress related proteins were expressed only in the biofilm condition, suggesting that the biofilm cells would constitutively express proteins in different adverse environments. Conclusions We observed overexpression of proteins related to quorum sensing, proving the existence of communication between cells, and thus the development of structuring the biofilm (mature biofilm) leading to obstruction of vessels and development of disease. This paper reports a first proteomic analysis of mature biofilm of X. fastidiosa, opening new perspectives for understanding the biochemistry of mature biofilm growth in a plant pathogen.

Atendimento online em bibliotecas: a experiência da Universidade de São Paulo

Os serviços de informação aliados às tecnologias evoluíram em sua forma de atuação à medida que oferecem, em menor tempo possível, informação segura de alcance maior aos usuários das bibliotecas. São inúmeros os conceitos de Serviço de Referência Virtual (SRV) que compartilham a ideia de que o uso das tecnologias de informação facilitam a comunicação entre bibliotecários e usuários. As Bibliotecas do Sistema Integrado de Bibliotecas da Universidade de São Paulo (SIBi/USP), detectaram a relevância de modernizar o Serviço de Atendimento ao Usuário, utilizando novos meios de comunicação e melhorando a interação com os usuários por meio de recursos que são de domínio e uso cotidiano dos mesmos. A Biblioteca da Faculdade de Medicina Veterinária e Zootecnia (FMVZ) da Universidade de São Paulo (USP) implantou o serviço de Atendimento Online por chat, disponibilizando aos seus usuários um novo canal de comunicação que permite o esclarecimento de dúvidas e solicitações em tempo real com atendentes. A experiência foi extremamente positiva convergindo para a implantação do sistema em outras quatro bibliotecas da USP

Atendimento online em bibliotecas: a experiência da Universidade de São Paulo

Os serviços de informação aliados às tecnologias evoluíram em sua forma de atuação à medida que oferecem, em menor tempo possível, informação segura de alcance maior aos usuários das bibliotecas. São inúmeros os conceitos de Serviço de Referência Virtual (SRV) que compartilham a ideia de que o uso das tecnologias de informação facilitam a comunicação entre bibliotecários e usuários. As Bibliotecas do Sistema Integrado de Bibliotecas da Universidade de São Paulo (SIBi/USP), detectaram a relevância de modernizar o Serviço de Atendimento ao Usuário, utilizando novos meios de comunicação e melhorando a interação com os usuários por meio de recursos que são de domínio e uso cotidiano dos mesmos. A Biblioteca da Faculdade de Medicina Veterinária e Zootecnia (FMVZ) da Universidade de São Paulo (USP) implantou o serviço de Atendimento Online por chat, disponibilizando aos seus usuários um novo canal de comunicação que permite o esclarecimento de dúvidas e solicitações em tempo real com atendentes. A experiência foi extremamente positiva convergindo para a implantação do sistema em outras quatro bibliotecas da USP

Optimization and control of a continuous polymerization reactor

This work studies the optimization and control of a styrene polymerization reactor. The proposed strategy deals with the case where, because of market conditions and equipment deterioration, the optimal operating point of the continuous reactor is modified significantly along the operation time and the control system has to search for this optimum point, besides keeping the reactor system stable at any possible point. The approach considered here consists of three layers: the Real Time Optimization (RTO), the Model Predictive Control (MPC) and a Target Calculation (TC) that coordinates the communication between the two other layers and guarantees the stability of the whole structure. The proposed algorithm is simulated with the phenomenological model of a styrene polymerization reactor, which has been widely used as a benchmark for process control. The complete optimization structure for the styrene process including disturbances rejection is developed. The simulation results show the robustness of the proposed strategy and the capability to deal with disturbances while the economic objective is optimized.

Web orientada a dispositivos móviles que comunican con otro sistema a través de Web Services

[ES] El proyecto consiste en establecer la comunicación entre dos portales web a través de servicios web Restful implementados en PHP. Ambos portales están relacionados con el mundo del cine. El segundo de estos es, a grandes rasgos, una interfaz simplificada del anterior. El primer portal web está construido sobre Drupal 7, en este instalamos una serie de módulos que nos permiten gestionar el contenido que se quiere mostrar a los usuarios. Un usuario que no se identifica podrá navegar por todas las páginas del portal, identificarse y registrarse. Los privilegios que se le conceden a un usuario cuando se identifica son los de participar en el sistema de votación de las películas e interactuar con otros usuarios identificados a través de un sistema de comentarios. El usuario administrador, además, puede gestionar el contenido y a los usuarios identificados. El segundo portal está orientado al disfrute de la página a través de dispositivos móviles. Un usuario que no se ha identificado puede navegar por todas las áreas de éste del mismo modo que un usuario identificado. En este portal, a diferencia del anterior, no es posible registrarse para este tipo de actores. La diferencia entre el usuario no identificado y el identificado, en este caso, es que este último al visualizar el catálogo observará un descuento sobre cada película. Los servicios web, a través de peticiones GET y POST, proporcionarán a los usuarios una rica experiencia de navegación. Gracias a estos, en el segundo portal, podrán identificarse, obtener el catálogo de películas (además de ordenarlo y establecer filtros de búsqueda por género), y visualizar la ficha de las películas y directores. Todo esto sin necesidad de crear otra base de datos, tan solo intercambiando datos con el servidor.

Las lenguas de extremo oriente y el español: los diccionarios y gramáticas como primeros instrumentos para la comunicación en Filipinas y China

[ES]En este trabajo mostraremos cómo desde los inicios de la Edad Moderna la lexicografía española se constituyó en uno de los vínculos que unían Europa, América y el Extremo Oriente. La modernización de la lexicografía en el continente europeo vino de la mano de Nebrija. Y, así, las nuevas gramáticas y diccionarios escritos para favorecer la comunicación entre los españoles y los pueblos del Extremo Oriente (Filipinas y China) llevaron más allá de las fronteras de España el modelo de Nebrija. Asimismo, ofrecemos un panorama de estas obras desde el siglo XVI hasta comienzos del siglo XX.

Presa di decisione in situazioni rischiose: effetto della rabbia

The current studies assessed the role of trait anger and anger expression styles on risk decision-making in adulthood, adolescence and childhood. In the first experiment 158 adults completed the STAXI-2 and an inventory consisting of a battery of hypothetical everyday decision-making scenarios. Participants were also asked to evaluate the perception of risk for each chosen option and some contextual characteristics, that are familiarity and salience for each scenario. The study provides evidence for a relationship between individual differences in the tendency to feel and express anger and risky decisions and for mediation effects of familiarity and salience appraisals. Moreover, results indicated that trait anger was predictive of risk perception and they provide evidence for a positive relationship between risk decision-making and risk perception. In the second study, we examined the relationship between specific components of anger (i.e., cognitive, affective and behavioural) and risk decision-making in adolescents. 101 subjects completed specific tasks, measuring risk decision-making, assessed using hypothetical choice scenarios, and anger, evaluated through the STAXI-CA and the MSAI-R. Results showed that adolescents higher on hostility, anger experience and destructive expression, make more risky decisions in everyday life situations. Moreover, regression analyses indicated that destructive expression of anger and hostility were predictive of adolescents’ risky decisions. In the third experiment, 104 children completed three tasks: the STAXI-CA, the MSAI-R and a task measuring risk decision-making in everyday situations. Subjects were also asked to evaluate the degree of danger, benefit, fun and fear perceived for each risky choice. Analyses indicated that: (a) risk decision-making was predicted by both trait anger and outward expression of anger; (b) destructive expression o anger was predictive of children’s risky decisions; (c) appraisal of danger fully mediated the relation between trait anger and risk; (d) perceptions of benefit, scare and fun partially mediated the relationship between trait anger and risk; and (e) appraisal of danger partially mediated the relationship between outward expression of anger and risk decision-making. The results provide evidence for a relationship between dispositional anger and risk decision-making during childhood, suggesting a possible explanation of the mechanisms below. In particular, risk decision-making can be viewed as the output of cognitive and emotive processes, linked to dispositional anger that leads children to be amused, optimistic and fearless in potentially risky situations. These findings substantiate the importance of incorporating cognitive and emotive factors in theories that seek to explain the relationship between personality traits and risk decision making across a broad range of age.

Studio e sviluppo di sistemi RFID in banda UHF

The recent widespread diffusion of radio-frequency identification (RFID) applications operating in the UHF band has been supported by both the request for greater interrogation ranges and greater and faster data exchange. UHF-RFID systems, exploiting a physical interaction based on Electromagnetic propagation, introduce many problems that have not been fully explored for the previous generations of RFID systems (e.g. HF). Therefore, the availability of reliable tools for modeling and evaluating the radio-communication between Reader and Tag within an RFID radio-link are needed. The first part of the thesis discuss the impact of real environment on system performance. In particular an analytical closed form formulation for the back-scattered field from the Tag antenna and the formulation for the lower bound of the BER achievable at the Reader side will be presented, considering different possible electromagnetic impairments. By means of the previous formulations, of the analysis of the RFID link operating in near filed conditions and of some electromagnetic/system-level co-simulations, an in-depth study of the dimensioning parameters and the actual performance of the systems will be discussed and analyzed, showing some relevant properties and trade-offs in transponder and reader design. Moreover a new low cost approach to extend the read range of the RFID UHF passive systems will be discussed. Within the scope to check the reliability of the analysis approaches and of innovative proposals, some reference transponder antennas have been designed and extensive measurement campaign has been carried out with satisfactory results. Finally, some commercial ad-hoc transponder for industrial application have been designed within the cooperation with Datalogic s.p.a., some guidelines and results will be briefly presented.

Role of BDNF secretion and signaling in the activity-dependent refinement of synaptic connections

Neuronal networks exhibit diverse types of plasticity, including the activity-dependent regulation of synaptic functions and refinement of synaptic connections. In addition, continuous generation of new neurons in the “adult” brain (adult neurogenesis) represents a powerful form of structural plasticity establishing new connections and possibly implementing pre-existing neuronal circuits (Kempermann et al, 2000; Ming and Song, 2005). Neurotrophins, a family of neuronal growth factors, are crucially involved in the modulation of activity-dependent neuronal plasticity. The first evidence for the physiological importance of this role evolved from the observations that the local administration of neurotrophins has dramatic effects on the activity-dependent refinement of synaptic connections in the visual cortex (McAllister et al, 1999; Berardi et al, 2000; Thoenen, 1995). Moreover, the local availability of critical amounts of neurotrophins appears to be relevant for the ability of hippocampal neurons to undergo long-term potentiation (LTP) of the synaptic transmission (Lu, 2004; Aicardi et al, 2004). To achieve a comprehensive understanding of the modulatory role of neurotrophins in integrated neuronal systems, informations on the mechanisms about local neurotrophins synthesis and secretion as well as ditribution of their cognate receptors are of crucial importance. In the first part of this doctoral thesis I have used electrophysiological approaches and real-time imaging tecniques to investigate additional features about the regulation of neurotrophins secretion, namely the capability of the neurotrophin brain-derived neurotrophic factor (BDNF) to undergo synaptic recycling. In cortical and hippocampal slices as well as in dissociated cell cultures, neuronal activity rapidly enhances the neuronal expression and secretion of BDNF which is subsequently taken up by neurons themselves but also by perineuronal astrocytes, through the selective activation of BDNF receptors. Moreover, internalized BDNF becomes part of the releasable source of the neurotrophin, which is promptly recruited for activity-dependent recycling. Thus, we described for the first time that neurons and astrocytes contain an endocytic compartment competent for BDNF recycling, suggesting a specialized form of bidirectional communication between neurons and glia. The mechanism of BDNF recycling is reminiscent of that for neurotransmitters and identifies BDNF as a new modulator implicated in neuro- and glio-transmission. In the second part of this doctoral thesis I addressed the role of BDNF signaling in adult hippocampal neurogenesis. I have generated a transgenic mouse model to specifically investigate the influence of BDNF signaling on the generation, differentiation, survival and connectivity of newborn neurons into the adult hippocampal network. I demonstrated that the survival of newborn neurons critically depends on the activation of the BDNF receptor TrkB. The TrkB-dependent decision regarding life or death in these newborn neurons takes place right at the transition point of their morphological and functional maturation Before newborn neurons start to die, they exhibit a drastic reduction in dendritic complexity and spine density compared to wild-type newborn neurons, indicating that this receptor is required for the connectivity of newborn neurons. Both the failure to become integrated and subsequent dying lead to impaired LTP. Finally, mice lacking a functional TrkB in the restricted population of newborn neurons show behavioral deficits, namely increased anxiety-like behavior. These data suggest that the integration and establishment of proper connections by newly generated neurons into the pre-existing network are relevant features for regulating the emotional state of the animal.

Correlazioni tra proprietá reologiche, struttura e processabilitá di blend di LLDPE/LDPE

Polymer blends constitute a valuable way to produce relatively low cost new materials. A still open question concerns the miscibility of polyethylene blends. Deviations from the log-additivity rule of the newtonian viscosity are often taken as a signature of immiscibility of the two components. The aim of this thesis is to characterize the rheological behavior in shear and elongation of five series of LLDPE/LDPE blends whose parent polymers have been chosen with different viscosity and SCB content and length. Synergistic effects have been measured for both zero shear viscosity and melt strength. Both SCB length and viscosity ratio between the components have been found to be key parameters for the miscibility of the pure polymers. In particular the miscibility increases with increasing SCB length and with decreasing the LDPE molecular weight and viscosity. This rheological behavior has significant effects on the processability window of these blends when the uni or biaxial elongational flows are involved. The film blowing is one of the processes for which the synergistic effects above mentioned can be crucial. Small scale experiments of film blowing performed for one of the series of blends has demonstrated that the positive deviation of the melt strength enlarges the processability window. In particular, the bubble stability was found to improve or disappear when the melt strength of the samples increased. The blending of LDPE and LLDPE can even reduce undesired melt flow instability phenomena widening, as a consequence, the processability window in extrusion. One of the series of blends has been characterized by means of capillary rheometry in order to allow a careful morphological analysis of the surface of the extruded polymer jets by means of Scanning Electron Microscopy (SEM) with the aim to detect the very early stages of the small scale melt instabilty at low shear rates (sharksin) and to follow its subsequent evolution as long as the shear rate was increased. With this experimental procedure it was possible to evaluate the shear rate ranges corresponding to different flow regions: smooth extrudate surface (absence of instability), sharkskin (small scale instability produced at the capillary exit), stick-slip transition (instability involving the whole capillary wall) and gross melt fracture (i.e. a large scale "upstream" instability originating from the entrance region of the capillary). A quantitative map was finally worked out using which an assessment of the flow type for a given shear rate and blend composition can be predicted.

A hybrid technology for parallel recording of single ion channels

Hybrid technologies, thanks to the convergence of integrated microelectronic devices and new class of microfluidic structures could open new perspectives to the way how nanoscale events are discovered, monitored and controlled. The key point of this thesis is to evaluate the impact of such an approach into applications of ion-channel High Throughput Screening (HTS)platforms. This approach offers promising opportunities for the development of new classes of sensitive, reliable and cheap sensors. There are numerous advantages of embedding microelectronic readout structures strictly coupled to sensing elements. On the one hand the signal-to-noise-ratio is increased as a result of scaling. On the other, the readout miniaturization allows organization of sensors into arrays, increasing the capability of the platform in terms of number of acquired data, as required in the HTS approach, to improve sensing accuracy and reliabiity. However, accurate interface design is required to establish efficient communication between ionic-based and electronic-based signals. The work made in this thesis will show a first example of a complete parallel readout system with single ion channel resolution, using a compact and scalable hybrid architecture suitable to be interfaced to large array of sensors, ensuring simultaneous signal recording and smart control of the signal-to-noise ratio and bandwidth trade off. More specifically, an array of microfluidic polymer structures, hosting artificial lipid bilayers blocks where single ion channel pores are embededed, is coupled with an array of ultra-low noise current amplifiers for signal amplification and data processing. As demonstrating working example, the platform was used to acquire ultra small currents derived by single non-covalent molecular binding between alpha-hemolysin pores and beta-cyclodextrin molecules in artificial lipid membranes.

Functional photoactive and electroactive nanodevices

Most of current ultra-miniaturized devices are obtained by the top-down approach, in which nanoscale components are fabricated by cutting down larger precursors. Since this physical-engineering method is reaching its limits, especially for components below 30 nm in size, alternative strategies are necessary. Of particular appeal to chemists is the supramolecular bottom-up approach to nanotechnology, a methodology that utilizes the principles of molecular recognition to build materials and devices from molecular components. The subject of this thesis is the photophysical and electrochemical investigation of nanodevices obtained harnessing the principles of supramolecular chemistry. These systems operate in solution-based environments and are investigated at the ensemble level. The majority of the chemical systems discussed here are based on pseudorotaxanes and catenanes. Such supramolecular systems represent prototypes of molecular machines since they are capable of performing simple controlled mechanical movements. Their properties and operation are strictly related to the supramolecular interactions between molecular components (generally photoactive or electroactive molecules) and to the possibility of modulating such interactions by means of external stimuli. The main issues addressed throughout the thesis are: (i) the analysis of the factors that can affect the architecture and perturb the stability of supramolecular systems; (ii) the possibility of controlling the direction of supramolecular motions exploiting the molecular information content; (iii) the development of switchable supramolecular polymers starting from simple host-guest complexes; (iv) the capability of some molecular machines to process information at molecular level, thus behaving as logic devices; (v) the behaviour of molecular machine components in a biological-type environment; (vi) the study of chemically functionalized metal nanoparticles by second harmonic generation spectroscopy.