Orientador: José Augusto Chinellato / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-20T02:47:46Z (GMT). No. of bitstreams: 1 Vicente_ElaineCristinaFarinchondePadua_M.pdf: 2256081 bytes, checksum: b35748a03035f4aa2a7be12161501597 (MD5) Previous issue date: 2012 / Resumo: Neste trabalho apresentamos a importância das câmaras de fotoemulsão que continuam, após décadas de uso, a oferecer atrativos para a física de partículas elementares. Citamos o detector OPERA (Oscillation Project with Emulsion-tRacking Apparatus), que é o maior detector de câmara de fotoemulsão-chumbo já construído (nove milhões de filmes de emulsão nuclear) como exemplo de sua aplicação na atualidade. Ele está presente no experimento de fluxo de neutrinos CNGS. Apresentamos também o detector CASTOR (Centauro And STrange Objects Research), que é um calorímetro hadrônico e eletromagnético de tungstênio e quartzo, desenvolvido para aprimorar o desempenho do experimento CMS (Compact Muon Solenoid) do LHC na região frontal. O CASTOR foi criado entre outras coisas, para o estudo de hádrons de longa penetração, observado em eventos de raios cósmicos ricos em hádrons. Estes foram identificados e chamados de strangelets. A proposta dos strangelets é que estes seriam produtos de decaimento de matéria de quarks rica em bárions, penetrariam grandes profundidades no chumbo e sairiam do detector quase não atenuados. Introduzimos os conceitos de chuveiros extensos atmosféricos e a técnica de câmara de fotoemulsão usada para o estudo destes. Ao mencionarmos o uso de câmaras de fotoemulsão em experimentos de montanha, não podemos deixar de citar a colaboração Brasil-Japão que detectou um evento exótico que passou a ser chamado de Centauro, por ter grande momento transversal. Além disso, a ausência de píons neutros é uma característica marcante deste tipo de evento. Vários outros eventos de mesmo tipo foram encontrados e a busca continua até hoje. Ainda falando sobre chuveiros atmosféricos, citamos como era feita a classificação de cascatas locais originadas pelas partículas da frente do chuveiro, na literatura das câmaras de fotoemulsões. O perfil longitudinal (em profundidade) de cada cascata local é usado para se determinar a energia da partícula incidente e também é um indicativo da sua natureza ¿ se faz parte da componente eletromagnética (elétron, pósitron ou gama) ou componente hadrônica. Cada cascata local observada é associada a um desses dois grupos. Apresentamos o software Geant como ferramenta de simulação deste trabalho. Originalmente desenvolvido no CERN para experimentos da física de altas energias, atualmente Geant é utilizado em outros campos como medicina e astrofísica. A versão mais recente (Geant4) também inclui tratamento de nêutrons de baixa energia (< 20 MeV) e de íons. Para a física de nêutrons, o Geant4 possui implementação de modelos de nêutrons de alta precisão que incluem os processos de colisões elásticas e inelásticas, captura e fissão. Para o tratamento de íons, foram implementados processos de colisão inelástica, decaimento radioativo e dissociação eletromagnética implementados para simulações. Apresentamos a geometria dos detectores tipo CBJ e tipo Pamir implementada com os recursos do Geant4. O detector tipo CBJ foi construído para o estudo de cascatas locais, produzidas em chumbo ou em carbono, no caso em que uma camada de ar serve como meio onde os secundários propagam-se e separam-se de modo a serem identificados a distâncias de centenas de micra ou mais; o perfil longitudinal é sempre usado para a análise. O detector tipo Pamir, composto somente de chumbo e filmes fotossensíveis, foi construído para o estudo de partículas de longa penetração e para analisar as profundidades em que os nêutrons podem iniciar cascatas em seu interior. Com os resultados obtidos, percebemos que há hádrons que podem interagir em grandes profundidades no chumbo, como o nêutron, em situações que poderiam ser erroneamente identificados como strangelets. Para determinar as características das cascatas assim produzidas, usamos o tratamento de colisões hadrônicas recentemente implantado no GEANT4. Este é um resultado importante deste trabalho ¿ mostramos que há uma probabilidade de identificação falsa de partículas / Abstract: This work introduces the importance of photoemulsion chambers that remain in use after decades and still offer many advantages for elementary particle physics. We cite OPERA (Oscillation Project with Emulsion-tRacking Apparatus) detector that is the greatest lead photoemulsion chamber detector ever constructed as an example of its application nowadays (nine million nuclear emulsion films). We also introduce the CASTOR detector (Centauro And STrange Objects Research) that is a hadronic and electromagnetic calorimeter of tungsten and quartz developed to improve the performance of CMS (Compact Muon Solenoid) experiment of LHC in its frontal region. One of most important features of Castor is its long dimension in the frontal region, which is suited to study long penetrating hadrons, as they appear in hadron-rich cosmic rays events. These hadrons were identified and called strangelets. The proposal of strangelets is that they were a result of baryon-rich quark matter decay and that they would penetrate great depth in lead and would leave the detector almost unattenuated. We presented the basic concepts of extensive air shower and the photoemulsion chamber technique used for its study. We introduce the use of photoemulsion chambers in mountain experiments and cited the Brasil-Japão Collaboration that detected an exotic event called Centauro for having large cross section. Besides, the absence of neutral pions is a remarkable feature of this type of event. Many other events of this type were detected and its search remains until today. Still talking about atmospheric showers, we cited how the classification of local cascades originated by frontal particles of shower were made in photoemulsion chamber literature. The longitudinal profile (in depth) of each local cascade is used to determine the energy of entering particle and it is also a signal of its nature ¿ if it is a part of electromagnetic component (electron, positron or gamma) or hadronic component. Each local cascade is observed is associated to one of these groups. We present Geant software as the simulation tool of this work. Originally developed at CERN for experiments of high energy physics, presently Geant is used in others fields as medicine and astrophysics. The most recent version of Geant is Geant4 and also includes low energy neutrons (< 20 MeV) and ion treatment. For neutron physics, Geant4 has the implementation of very high precision neutron models that include elastic and inelastic collision process, capture and fission. For ion treatment, we have inelastic collisions, radioactive decay and electromagnetic dissociation implemented for simulations. We introduce the CBJ and Pamir detectors geometry implemented with Geant4 resources. The CBJ detector was constructed to study local cascades produced in lead or carbon when an air layer is used as a mean where secondary particles propagates and are separated in distances of micra or greater. The longitudinal profile is always used for the analysis. The Pamir detector, made of only lead and photosensitive films, was constructed to study long penetrating particles and to study the depths that neutrons begins its cascade. The results obtained show that there are hadrons, for instance neutrons, interacting in great depths of lead in cases that it could be misidentified as strangelet. To determine the features of cascades produced this way, we used the hadronic collision treatment recently implemented in Geant4. This is an important result because we showed that there is a probability of false identification of particles / Mestrado / Física / Mestra em Física

The aim of the study was to assess the possibilities in using ground-penetrating radar to identify small-scale stratigraphy in the upper 1 m of a soil profile and to statistically identify differences in the stratigraphic units discovered using the GPR unit. The study area is ca 15 km southwest of Lycksele near a gravel pit on the banks of Örån. It was located on top of a large (&gt;5 m thick) glacifluvial deposit of indeterminate age overlayed by till from the latest deglaciation. The data sampled included 22 radargrams depicting a total length of &gt;1000 m as well as soil samples from three stratigraphic units from three different trenches (9 samples in total). Visual analysis of the stratigraphy took place via trenches as well as by studying the radar images. The radar images show that three stratigraphic units can be identified clearly (ablation till, S1, a transitional layer of mixed till and glacifluvium, S2, and the underlying glacifluvium, S3) but that the border between the two lower units can be opaque at times. Field observations showed this to be due to the genesis of the topmost unit, the ablation till. Observations in the field also showed relict podsolization in a kettle in the northern part of the study area. Grain-size comparison of the three stratigraphic units identified was performed via sieving. Calculations of the weight percentage were then used for statistical analysis to identify any differences between the strata. Results show that there are differences regarding fine material (ø &lt;0.074 mm, p=0.038), gravel (ø &gt; 2 mm, p&lt;0.0001) and sand (p=0.027) within these three stratigraphic units.

In a periglacial environment it is important to know the thickness, orientation and structureof sediments when assessing the landscape and its hydrological pathways. Using a groundpenetratingradar (GPR) I have profiled large areas of the subsurface in a catchment area to alake on western Greenland. Post-processing and calculations of the gathered data has revealedthat the sediment thickness is maximum 15 meters in the valleys. Due to the fact that nocorrelation data is available, such as boreholes or pits, this estimation has large error limits butthe profiles gathered reveals the structure in the subsurface to a great extent.

Les peptides pénétrants (CPP) se caractérisent par deux propriétés : ils pénètrent dans l'espace intracellulaire et favorisent l'internalisation de cargaisons moléculaires auxquelles ils sont associés. Si les CPP sont très utilisés comme vecteurs en recherche fondamentale, la méconnaissance des mécanismes de pénétration et de leurs distributions intracellulaires limite leur utilisation thérapeutique. Il est admis que les CPP et leurs cargaisons sont internalisés par transport actif (endocytose) et par transport passif (translocation directe). J'ai étudié la translocation directe à l'échelle moléculaire en utilisant des membranes modèles. Les CPP usuels sont internalisés et permettent l'accumulation de cargaisons dans des vésicules unilamellaires. J'ai alors démontré que la translocation directe se déroule via la formation de complexes neutres et hydrophobes CPP-phospholipides.La pénétration intracellulaire des CPP est le plus souvent étudiée par microscopie confocale. J'ai démontré que des fortes concentrations locales de CPP induit une auto-inhibition de leur fluorophore. Cet artefact a conduit à des erreurs d'interprétation dans la littérature quant à la localisation des CPP. Un protocole permettant de révéler la fluorescence éteinte a été proposé et conduit à réévaluer la localisation subcellulaire des CPP ainsi que l'importance relative des mécanismes d'internalisation.Ces résultats ont permis de développer rationnellement de nouveaux vecteurs pénétrants : les oligoarginines acylées par des chaînes grasses dont des insaturations sont de stéréochimie cis. Leur internalisation passive particulièrement importante conduit à la libération de la cargaison dans le cytosol. / Cell penetrating peptides (CPPs) are short cationic sequences capable of shuttling bioactive cargoes into eukaryotic cells. If CPPs are common delivery tools in basic research, their therapeutic use is currently limited because their internalization mechanisms and intracellular distributions remain to be elucidated. In living cells there is evidence for both endocytosis of the CPPs and for “direct translocation”, an energy-independent uptake pathway. I analyzed the direct translocation phenomenon at the molecular level with model membranes. CPPs are internalized into large unilamellar vesicles and trigger the internalization of various cargoes. I then demonstrated that direct translocation occurs through membranes via the formation of a neutral and hydrophobic CPP-anionic phospholipids complex. CPPs internalization is mostly analyzed by confocal microscopy. I demonstrated that fluorescence self-quenching occurs if fluorescently labeled CPPs are locally too concentrated. This severe artifact led to misinterpretation of the subcellular distribution of CPPs. I developed a reliable procedure to avoid this artifact and ranked subcellular regions of living cells depending on their CPP concentration. As a result, I was able to rationalize the subcellular distribution of CPPs and to deduce their penetration mechanisms. The studies that I performed provided valuable information that I used to design a new family of delivery vectors: minimalist oligoarginines peptides acylated by unsaturated fatty acids (cis unsaturations). The direct translocation of these lipopeptides is particularly important yielding to an efficient delivery of a cargo inside the cytosol of living cells.

L’objectif du projet est de comprendre l’effet du peptide vecteur (R/W)9 sur les cellules tumorales EF, modèles du sarcome d’Ewing. En effet, ce peptide a la capacité de remodeler le cytosquelette d’actine dans ces cellules, ainsi que de réduire leur motilité et leur aptitude à croître en indépendance d’ancrage (Delaroche D. JBC 2010).La première étape de ce travail a été la caractérisation in vitro de l’interaction directe avec l’actine par cross-linking chimique et spectrométrie de masse (Clavier S. EuProt 2014). Ensuite, pour avancer dans la compréhension de l’effet du peptide (R/W)9, deux approches ont été développées.La première approche, basée sur du photocross-linking in cellulo ou in lysat, vise à identifier des partenaires intracellulaires du peptide vecteur. Pour cela, nous avons mis au point et validé biologiquement une version photoactivable du peptide (R/W)9. Puis, avant de passer sur cellules entières, nous nous sommes assurés de la faisabilité de la réaction de photocross-linking in vitro sur un système d’interaction modèle que nous avons également utilisé pour développer un logiciel capable d’interpréter les spectres MS/MS d’espèces photocross-linkées (Xlink-Identifier, Collaboration Dr Du X). Des expériences de purification d’affinité ont également été menées en immobilisant le peptide (R/W)9 sur des billes de streptavidine ensuite mises en présence de lysat cellulaire. Les protéines capturées ont été identifiées par spectrométrie de masse haut-débit. La seconde approche est de la protéomique différentielle avec un marquage SILAC et a pour objectif de mettre en évidence l’influence du peptide vecteur sur l’expression des protéines. / The aim of the project is to understand the effect of (R/W)9 cell penetrating peptide (CPP) on EF tumoral cells, an Ewing sarcoma model cell line. Actually, this peptide is able to remodel the actin cytoskeleton of these cells, to decrease their motility as well as their ability to grow without anchorage (Delaroche D. JBC 2010).The first step of this work was to characterize the in vitro interaction with actin using chemical cross-linking and mass spectrometry (Clavier S. Euprot 2014). Then, in order to get a deeper understanding of (R/W)9 peptide effect, two approaches were developed. The goal of the first approach based on in cellulo or in lysate photocross-linking is to identify (R/W)9 CPP’s partners. To do this, we designed and biologically validated a photoactivable version of (R/W)9 peptide. Then, before starting to work with living cells, we checked the feasibility of in vitro photocross-linking on a model interacting system that we also used to develop a software able to interpret MS/MS spectra of photocross-linked species. (Xlink-Identifier, Collaboration with Dr. X. Du.). Affinity purification experiments were also performed by incubating streptavidin magnetic beads bearing (R/W)9 peptide with cell lysates. Captured proteins were identified using high-throughput mass spectrometry. The second approach is differential proteomic with SILAC labelling and aims at assessing the influence of (R/W)9 CPP on proteins expression.

Master of Science / Department of Civil Engineering / Eric J. Fitzsimmons / The rail industry's recent shift towards larger and heavier railcars has influenced Class III / short line railroad operation and track maintenance costs. Class III railroads earn less than $38.1 million in in annual revenue and generally operate first and last leg shipping for their customers. In Kansas, Class III railroads operate approximately 40 percent of the roughly 2,800 miles (4,500 km) of rail; however, due to the current Class III track condition they move lighter railcars at lower speeds than Class I railroads. The State of Kansas statutorily allots $5 million to support rail improvement projects, primarily for Class III railroads. Therefore, the objective of this study was to conduct an inventory of Kansas’s Class III rail network to identify the track segments in need of this support that would be most beneficial to the rail system. Representatives of each railroad were contacted and received a survey requesting information regarding the operational and structural status of their systems. The data collected were organized and processed to determine the sections of track that can accommodate the heavier axle load cars that are currently being utilized by Class I railroads. This study identified that Class III railroads shipped over 155,000 carloads of freight in 2016 and 30 percent of Kansas’s Class III track can currently accommodate heavy axle cars. The increased load from the increased railcar size has also increased the risk of damage to railroad’s track structure. Railroad ballast is the free draining granular material that supports the track structure. As the track ages, small particles can fill the voids of the granular material which is a process known as fouling. Established methods for determining the fouling of a section of ballast are destructive tests that usually require the railroad to restrict or reroute traffic on its network. Ground Penetrating Radar (GPR) is a nondestructive geophysical surveying method that measures the time required for electromagnetic wave impulses to reflect off differing subsurface interfaces. Historically, GPR surveys of track structures primarily determine the depth of ballast and track geometry. The objective of this study was to determine the viability of utilizing the laboratory’s existing GPR equipment to develop a methodology of measuring ballast fouling nondestructively. A 48 x 48 x 48 in (1.2 x 1.2 x 1.2 m) test box was built. The test box was filled with 48 in (1.2 m) of clean and ballast. Tests were run on dry and partially saturated material, wetted using 6 gallons (22.7 L). GPR data were collected hourly for the first 6 hours, then at the multiples of 12 and 24 hour marks for one week. Sand was chosen as an absorbent geologic material for the second stage of testing since no fouled ballast could be acquired at the time of the study. A 27 x18 x 18 in (0.69 x 0.46 x 0.046 m) box was filled with sand and wetted with water in one gallon (7.5 L) increments. GPR scans and samples to determine the water content were collected after the addition of each gallon. The data collected were processed to determine soil properties. Preliminary results from this research indicate that the GPR set up utilized can effectively determine the dielectric constant of geologic materials including ballast, although the dielectric constant is highly dependent on the volumetric moisture content of the material.

Scărişoara Ice Cave has been a catalyst of scientific intrigue and effort for over 150 years. These efforts have revealed and described countless natural phenomena – and in the process have made it one of the most studied caves in the world. Of especial interest is the massive ice block located within its Great Hall and scientific reservations. The ice block, which is the oldest and largest known to exist in a cave, has been the focus of multiple surveying and mapping efforts, typically ones utilizing traditional equipment. In this study, the goals were to reconstruct the ice block/cave floor interface and to estimate the volume of the ice block. Once the models were constructed, we aimed to study the relationships between the cave and ice block morphologies. In order to accomplish this goal, three (3) main datasets were collected, processed, and amalgamated. Ground penetrating radar data was used to discern the floor morphology below the ice block. Over 1,500 photographs were collected in the cave and used with Structure from Motion photogrammetry software to construct a texturized 3D model of the cave and ice surfaces. And a total station survey was performed to scale, georeference, and validate each model. Once georeferenced, the data was imported into an ArcGIS geodatabase for further analysis. The methodology described within this study provides a powerful set of instructions for producing highly valuable scientific data, especially related to caves. Here, we describe in detail the novel tools and software used to validate, inspect, manipulate, and measure morphological information while immersed in a fully 3D experience. With this methodology, it is possible to easily and inexpensively create digital elevation models of underground rooms and galleries, to measure the differences between surfaces, to create 3D models from the combination of surfaces, and to intimately inspect a subject area without actually being there. At the culmination of these efforts, the partial ice block volume was estimated to be 118,000 m3 with an uncertainty of ± 9.5%. The volume computed herein is significantly larger than previously thought and the total volume is likely significantly larger, since certain portions were not modeled during this study. In addition, the morphology of ceiling enlargement was linked to areas of high elevation at the base of the ice block. A counterintuitive depression was recognized at the base of the Entrance Shaft. The thickest areas of the ice were identified for future coring projects. And combining all this a new informational allowed us to propose a new theory on the formation of the ice block and to decipher particular speleogenetic aspects.

The cell membrane is an impermeable barrier for most macromolecules. Recently discovered cell-penetrating peptides (CPPs) have gained lot of attention because they can cross the membrane, and even more, carry cargoes with them. How CPPs enter cells is still not clear, while the delivery of different cargoes has been convincingly shown. This thesis concentrates on evaluating CPPs as vectors for different biologically relevant cargoes. Proposed internalisation mechanisms are reviewed as well as cargo coupling strategies. Biological activities of antisense oligonucleotides delivered by CPPs have been of particular interest and are explained in greater details. A new CPP, pIsl, was derived from Islet-1 transcription factor, and compared to archetypical CPPs like penetratin and transportan. All three peptides resided in the headgroup region of lipid bilayers in model membranes. However, penetratin and pIsl did only interact with negatively charged membranes, while transportan did not distinguish negatively charged and neutral membranes. This suggests different translocation pathways for different CPPs. Biotinylated pIsl and penetratin were complexed with avidin, and uptake of avidin into the human melanoma cell line Bowes was observed in both cases. This means that the protein is not unfolded during the translocation process, which is important in delivery of other, biologically active proteins. Transportan and its analogue TP10 were used for peptide nucleic acid (PNA) antisense oligonucleotide delivery. First, eight human galanin receptor type 1 targeting PNA oligomers were designed, conjugated to transportan and assayed for antisense efficiency. In contrary to avidin-biotinylated peptide conjugate, a covalent bond between PNA oligomers and the transport peptide was necessary for cellular uptake of oligomers. A common problem in antisense technology is inactivity of antisense oligonucleotides due to the secondary structure of the target. Efficiencies of tested galanin receptor type 1 targeting PNA oligomers varied over two orders of magnitude. The most efficient oligomers were targeting coding sequence regions 24-38 and 27-38, and had EC50 values 70 and 80 nM, respectively. TP10-antisense PNA oligomer conjugates were targeted also to L-type voltage dependent Ca2+ channel subunits CaV1.2 and CaV1.3. Specific down-regulation of respective proteins was demonstrated by immunohistochemistry. Physiological response to the down-regulation of either of Ca2+ channels was studied by alteration of flexor reflex sensitisation. Rats treated with either of the antisense PNA, but not with scrambled PNA lost the action potential windup phenomenon. In conjunction with a variety of drugs, modulating the conductivity and excitability of neuronal membranes, a central role of L-type CaV channels in sensitisation was confirmed. Nevertheless, also N-methyl-D-aspartate and glycine receptors were found to be required. Finally, delivery of plasmids by TP10 was evaluated. In contrary to many similar CPPs, TP10 was incapable to translocate plasmids to cells. However, addition of TP10 or a TP10-PNA conjugate to polyethyleneimine-condensed plasmids increased the expression of reporter genes. In summary, different types of cargoes have been delivered by CPPs and different cargo coupling strategies have been used. CPP-mediated antisense oligonucleotide delivery has been used to identify accessible sites in human galanin receptor type 1 mRNA and to determine the role of L-type voltage dependent Ca2+ channels in axon potential windup.

This study presents a comprehensive overview of the current state of the Milne Ice Shelf and how it has changed over the last 59 years. The 205 ±1 km2 ice shelf experienced a 28% (82 ±0.8 km2) reduction in area between 1950 – 2009, and a 20% (2.5 ±0.9km3 water equivalent (w.e.)) reduction in volume between 1981 – 2008/2009, suggesting a long-term state of negative mass balance. Comparison of mean annual specific mass balances (up to -0.34 m w.e. yr-1) with surface mass balance measurements for the nearby Ward Hunt Ice Shelf suggest that basal melt is a key contributor to total ice shelf thinning. The development and expansion of new and existing surface cracks, as well as ice-marginal and epishelf lake development, indicate significant ice shelf weakening. Over the next few decades it is likely that the Milne Ice Shelf will continue to deteriorate.

This study presents the first comprehensive assessment of the Petersen Ice Shelf and the Petersen Bay epishelf lake, and examines their current characteristics and changes to their structure between 1959 and 2012. The surface of the Petersen Ice Shelf is characterized by a rolling topography of ridges and troughs, which is balanced by a rolling basal topography, with thicker ice under the surface ridges and thinner ice under the surface troughs. Based on thickness measurements collected in 2011 and area measurements from August 2012, the Petersen Ice Shelf has a surface area of 19.32 km2 and a mean thickness of 29 m, with the greatest thicknesses (>100 m) occurring at the fronts of tributary glaciers feeding into the ice shelf. The tributary glaciers along the northern coast of Petersen Bay contributed an estimated area-averaged 7.89 to 13.55 cm yr-1 of ice to the ice shelf between 2011 and 2012. This input is counteracted by a mean surface ablation of 1.30 m yr-1 between 2011 and 2012, suggesting strongly negative current mass balance conditions on the ice shelf. The Petersen Ice Shelf remained relatively stable until 2005 when the first break-up in recent history occurred, removing >8 km2 of ice shelf surface area. This break-up led to the drainage of the epishelf lake once the ice shelf separated from the southern coast, providing a conduit through which the freshwater from the lake escaped. More break-ups occurred in summers 2008, 2011 and 2012, which resulted in a >31.2 km2 loss in surface area (~63% of June 2005 area). While ephemeral regions of freshwater have occurred along the southern coast of Petersen Bay since 2005 (with areas ranging from 0.32-0.53 km2), open water events and a channel along the southern coast have prevented the epishelf lake from reforming. Based on these past and present observations it is unlikely that Petersen Ice Shelf will continue to persist long into the future.