Influenza di alcune proprietà chimiche e idrauliche sui processi di adsorbimento e movimento di glifosate in suoli di alta e bassa pianura veneta Influence of some chemical and hydraulic proprieties on the process of adsorption and movement of glyphosate in soils of the upper and lower Veneto plain

Among the ecosystem services delivered by the soil, the soil filtering against potential contaminants of the water resource -such as plant protection products- is of primary importance. Nevertheless, the multitude of exogenous substances on the market and their different physicochemical characteristics, as well as the strong site-specific variability of the soils, makes it difficult to accurately predict the environmental fate of such molecules that are released into the environment. With this thesis work, some hydraulic and chemical properties of different agricultural soils of the Veneto region were analyzed, with the aim of understanding the dynamics that regulate adsorption and transport phenomena of glyphosate, and determine the susceptibility of the territory to subsurface water contamination. Two soils were sampled in Colnù (Conegliano) and Settolo (Valdobbiadene) sites in the northern Veneto plain, and compared with a Cambisol soil, typical of the low-lying venetian plain and located at the Experimental Farm of the University of Padua in Legnaro (Padua), which usually has a shallow water table around 1 m depth. Chemical analyses at different depths were performed to determine Al and Fe oxide and hydroxide contents, whose quantification is crucial to better understand the adsorption of glyphosate to the soil. Also, the adsorption coefficients were experimentally determined and described according to Freundlich isotherms. As for the soil hydraulic properties, undisturbed samples at different depths were analyzed by determining the saturated water conductivity and the water retention curve. Finally, the HYDRUS-1D hydrological model was fed with the experimental data previously obtained and used to simulate the environmental fate of glyphosate across the soil in each site-specific context. Each simulation involved the application of glyphosate in pre-sowing conditions on a maize crop, repeated in three consecutive years. Results showed that Fe and Al oxides and hydroxides increased with the depth in Legnaro soil, where the extraction method with oxalate returned the greatest quantity of both Fe and Al oxides. In contrast, results from Colnù and Settolo did not follow the same trend as per Legnaro. In particular, the oxalate extraction method results in extracting greater quantities of oxides and hydroxides only in the Conegliano sites; in Valdobbiadene the oxides most extracted are those chelated to the organic matter. extracted with pyrophosphate. As regards the Kf, the highest values were found in Conegliano. Correlation analysis showed that the content of fine soil particles –silt and clay– and the SOM-chelated oxides determined an increase in Kf. Numerical simulations highlighted the pivotal role of a shallow water table in promoting the movement of glyphosate which, despite its affinity for the soil phase, partly moved towards the deep layers favored by high soil moisture and water conductivity. On the other hand, in high plain soils, or where the aquifer is deep, glyphosate tends to slow down its movement, to be adsorbed to soil particles, and therefore degrade before reaching the aquifer. In-depth site-specific investigations are required to provide to policy makers and local authorities useful 4 tools to define more precisely the areas more or less susceptible to possible environmental contamination, both for the surface and sub-surface waters, so as to identify safeguard and protection actions

Desenvolvimento de fontes laser, espectroscopia de alta resolução e resfriamento e aprisionamento magneto-óptico de átomos de cálcio

Orientador: Flavio Caldas da CruzTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb WataghinResumo: Neste trabalho, abordamos o desenvolvimento de um sistema experimental para resfriamento laser e aprisionamento magneto-óptico de átomos de cálcio, o desenvolvimento de fontes laser empregadas nesse sistema, bem como estudos espectroscópicos de transições desse elemento em descargas elétricas de catodo oco. No caso do cálcio, a transição óptica mais eficiente para a manipulação do movimento dos átomos por pressão de radiação é a 1 S0-1 P1 em 423 nm. Uma das fontes de radiação laser que desenvolvemos para esse comprimento de onda consiste de um laser de Ti:Safira estabilizado e duplicado em freqüência. A freqüência desse laser é travada à ressonância de uma cavidade de Fabry-Perot de referência. O segundo harmônico do laser é gerado por conversão não-linear em um cristal de niobato de potássio situado em uma cavidade externa de amplificação. Investigamos o uso de lâmpadas de catodo oco de cálcio como ferramentas espectroscópicas de alta resolução. A variação na impedância da descarga elétrica que ocorre com a excitação laser, o efeito optogalvânico, é uma técnica de alta sensibilidade que simplifica consideravelmente a detecção e a sintonia em transições atômicas muito fracas como a 1 S0-3 P1 em 657 nm. O sistema de resfriamento e aprisionamento de átomos de cálcio é o último tópico abordado neste trabalho. Nesse sistema, átomos provenientes de um feixe atômico térmico são resfriados pela técnica de desaceleração Zeeman e então capturados em uma armadilha magneto-óptica. Empregamos um esquema alternativo de desaceleração Zeeman que usa um feixe laser com a mesma freqüência dos feixes da armadilha. Estudamos a variação do número estacionário de átomos aprisionados com vários parâmetros, como o gradiente de campo magnético, a dessintonia e a intensidade dos feixes laser de aprisionamento e desaceleração. Analisamos também a evolução temporal do número de átomos aprisionados. Esse estudo mostrou que o tempo de armazenamento na armadilha é limitado por perdas devido ao bombeamento óptico de níveis metaestáveis do cálcio. Essas perdas por bombeamento óptico são muito maiores do que as perdas decorrentes de colisões binárias entre os átomos frios. Nesse regime, o comportamento não-exponencial do número de átomos torna-se muito difícil de ser observado. Todavia, constatamos que é possível extrair informações relativas à taxa de perdas por colisões frias comparando as constantes de tempo exponenciais das curvas de carga e descargaAbstract: In this work, we report on an experimental system for laser cooling and magneto-optical trapping of calcium atoms, the development of the laser sources for this system, and a spectroscopic analysis of calcium transitions in hollow cathode electric discharges. In the case of calcium, the most efficient optical transition for the atom motion manipulation by radiation pressure is the 1 S0- 1 P1 at 423 nm. One of the lasers sources that we developed at this wavelength consists on a frequency doubled and stabilized Ti:Sapphire laser. The frequency of this laser is locked to the resonance of a Fabry-Perot reference cavity. The second harmonic is generated by nonlinear conversion in a potassium niobate crystal inside an external power enhancement cavity. We investigate the use of calcium hollow cathode lamps as high resolution spectroscopic tools. The variation of the electrical discharge caused by the laser excitation, the optogalvanic effect, is a high sensitivity technique that greatly simplifies the detection and tuning on very weak atomic transitions, as the 1 S0-3 P1 at 657 nm. The system for cooling and trapping of calcium atoms is the last topic reported in this work. In this system, atoms from a thermal atomic beam are first cooled by the Zeeman deceleration technique and then trapped on a magneto-optical trap. We employed an alternative scheme for Zeeman deceleration which uses a laser beam at the same frequency of the trapping laser beams. We analyzed the variation of the steady state number of trapped atoms with several parameters, as magnetic field gradient, detuning and intensity of the trapping and decelerating laser beams. We also analyzed the time evolution of the number of trapped atoms. This analysis showed that the trap storage time is limited by losses related with the optical pumping of calcium metastable levels. These optical pumping losses are much larger than the losses caused by binary collisions between the cold atoms. In this regime, the non-exponential behavior of the atom number is very difficult to observe. However, we noticed that it is possible to extract information on the cold collision loss rate by comparing the exponential time constants of the trap load and the decay curvesDoutoradoFísicaDoutor em Ciência

A corpus analysis of online news comments using the Appraisal framework

We present detailed analyses of the distribution of Appraisal categories (Martin and White, 2005) in a corpus of online news comments. The corpus consists of just over one thousand comments posted in response to a variety of opinion pieces on the website of the Canadian newspaper The Globe and Mail. We annotated all the comments with labels corresponding to different categories of the Appraisal framework. Analyses of the annotations show that comments are overwhelmingly negative, and that they favour two of the subtypes of Attitude (Judgment and Appreciation) over the third, Affect. The paper contributes a methodology for annotating Appraisal, and results that show the interaction of Appraisal with negation, the constructive (or not) nature of comments, and the level of toxicity found in them. The results show that highly opinionated language is expressed as an objective opinion (Judgement and Appreciation) rather than an emotional reaction (Affect). This finding, together with the interplay of evaluative language with constructiveness and toxicity in the comments, can be applied to the automatic moderation of comments

Synthesis and characterization of multifunctional nanovesicles composed of POPC lipid molecules for nuclear imaging

The integration of nuclear imaging analysis with nanomedicine has tremendously grown and represents a valid and powerful tool for the development and clinical translation of drug delivery systems. Among the various types of nanostructures used as drug carriers, nanovesicles represent intriguing platforms due to their capability to entrap both lipophilic and hydrophilic agents, and their well-known biocompatibility and biodegradability. In this respect, here we present the development of a labelling procedure of POPC (1-palmitoyl-2-oleoyl-sn-glycero-3- phosphocholine)-based liposomes incorporating an ad hoc designed lipophilic NOTA (1, 4, 7- triazacyclononane-1, 4, 7-triacetic acid) analogue, derivatized with an oleic acid residue, able to bind the positron emitter gallium-68(III). Based on POPC features, the optimal conditions for liposome labelling were studied with the aim of optimizing the Ga(III) incorporation and obtaining a significant radiochemical yield. The data presented in this work demonstrate the feasibility of the labelling procedure on POPC liposomes co-formulated with the ad hoc designed NOTA analogue. We thus provided a critical insight into the practical aspects of the development of vesicles for theranostic approaches, which in principle can be extended to other nanosystems exploiting a variety of bioconjugation protocols

Dissociative Photoionization of Methyl Thiochloroformate, ClC(O)SCH3, following Sulfur 2p, Chlorine 2p, Carbon 1s and Oxygen 1s Excitations

The electronic transitions and the dissociativeionic photoionization mechanisms of gaseous ClC(O)SCH3have been investigated at the VUV and soft X-ray energyregions of S 2p, Cl 2p, C 1s, and O 1s core edges using tunablesynchrotron radiation and time-of-flight mass spectrometry.The relative abundances of the ionic fragments were obtainedfrom both PEPICO (photoelectron photoion coincidence)and PEPIPICO (photoelectron photoion photoion coincidence)spectra. The presence of a moderate site- and element-specific fragmentation effects and its implication regardingchemical reactions were analyzed. The relationship of the current results with the interstellar chemistry is also a goal of this pieceof work.Fil: Geronés, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Romano, Rosana Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Cavasso Filho, Reinaldo L.. Universidade Federal do ABC; BrasilFil: Della Védova, Carlos O.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Calcium magneto-optical trap loaded from a decelerated atomic beam

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOWe describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.332355362FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSem informaçãoSem informaçãoSem informaçãoWe would like to acknowledge the glass shop of the UNICAMP Physics Institute for the very well done work in the construction of the atomic beam and MOT glass chamber. We also would like to thank the machine shop and J.B.Rodrigues for the mechanical parts. This work was supported by FAPESP, CAPES and CNPq and FAEPUNICAMP, Brazilian government agencies. Support for RLCF was through CAPES graduate research scholarship and for DAM and DRO through FAPESP graduate and undergraduate scholarships respectively

Valence and inner electronic excitation, ionization, and fragmentation of perfluoropropionic acid

The photoexcitation, photoionization, and photofragmentation of gaseous CF3CF2C(O)OH were studied by means of synchrotron radiation in the valence and inner energy regions. Photofragmentation events were detected from 11.7 eV through formation of COH+, C2F4+, and the parent species M+. Because the vertical ionization potential has been reported at 11.94 eV, the starting energy used in this study, 11.7 eV, falls just inside of the tail of the ionization band in the photoelectron spectra. Information from the total ion yield spectra around the C 1s, O 1s, and F 1s ionization potentials allows the energies at which different resonance transitions take place in the molecule to be determined. These transitions have been assigned by comparison with the results of the analysis of similar compounds. In the inner energy region, both kinetic energy release (KER) values and the slope and shape of double coincidence islands obtained from photoelectron–photoion–photoion coincidence (PEPIPICO) spectra allow different photofragmentation mechanisms to be elucidated.Centro de Química Inorgánic

The antimicrobial peptide Magainin-2 interacts with BamA impairing folding of E. coli membrane proteins

: Antimicrobial peptides (AMPs) are a unique and diverse group of molecules endowed with a broad spectrum of antibiotics properties that are being considered as new alternative therapeutic agents. Most of these peptides are membrane-active molecules, killing bacteria by membrane disruption. However, recently an increasing number of AMPs was shown to enter bacterial cells and target intracellular processes fundamental for bacterial life. In this paper we investigated the mechanism of action of Maganin-2 (Mag-2), a well-known antimicrobial peptide isolated from the African clawed frog Xenopus laevis, by functional proteomic approaches. Several proteins belonging to E. coli macromolecular membrane complexes were identified as Mag-2 putative interactors. Among these, we focused our attention on BamA a membrane protein belonging to the BAM complex responsible for the folding and insertion of nascent β-barrel Outer Membrane Proteins (OMPs) in the outer membrane. In silico predictions by molecular modelling, in vitro fluorescence binding and Light Scattering experiments carried out using a recombinant form of BamA confirmed the formation of a stable Mag-2/BamA complex and indicated a high affinity of the peptide for BamA. Functional implications of this interactions were investigated by two alternative and complementary approaches. The amount of outer membrane proteins OmpA and OmpF produced in E. coli following Mag-2 incubation were evaluated by both western blot analysis and quantitative tandem mass spectrometry in Multiple Reaction Monitoring scan mode. In both experiments a gradual decrease in outer membrane proteins production with time was observed as a consequence of Mag-2 treatment. These results suggested BamA as a possible good target for the rational design of new antibiotics since this protein is responsible for a crucial biological event of bacterial life and is absent in humans

Charge-transfer interactions stabilize g-quadruplex-forming thrombin binding aptamers and can improve their anticoagulant activity

In the search for optimized thrombin binding aptamers (TBAs), we herein describe the synthesis of a library of TBA analogues obtained by end-functionalization with the electron-rich 1,5-dialkoxy naphthalene (DAN) and the electron-deficient 1,8,4,5-naphthalenetetra-carboxylic diimide (NDI) moieties. Indeed, when these G-rich oligonucleotides were folded into the peculiar TBA G-quadruplex (G4) structure, effective donor–acceptor charge transfer interactions between the DAN and NDI residues attached to the extremities of the sequence were induced, providing pseudo-cyclic structures. Alternatively, insertion of NDI groups at both extremities produced TBA analogues stabilized by π–π stacking interactions. All the doubly-modified TBAs were characterized by different biophysical techniques and compared with the analogues carrying only the DAN or NDI residue and unmodified TBA. These modified TBAs exhibited higher nuclease resistance, and their G4 structures were markedly stabilized, as evidenced by increased Tm values compared to TBA. These favorable properties were also associated with improved anticoagulant activity for one DAN/NDI-modified TBA, and for one NDI/NDI-modified TBA. Our results indicated that TBA pseudo-cyclic structuring by ad hoc designed end-functionalization represents an efficient approach to improve the aptamer features, while pre-organizing and stabilizing the G4 structure but allowing sufficient flexibility to the aptamer folding, which is necessary for optimal thrombin recognition