Measurement of single spin asymmetry and fifth structure function for the p( e&ar; ,e'K +)Λ reaction with CEBAF Large Acceptance Spectrometer (CLAS)

The single spin asymmetry, ALT ′, and the polarized structure function, σ LT′, for the p( e&ar; , e′K +)Λ reaction in the resonance region have been measured and extracted using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Data were taken at an electron beam energy of 2.567 GeV. The large acceptance of CLAS allows for full azimuthal angle coverage over a large range of center-of-mass scattering angles. Results were obtained that span a range in Q 2 from 0.5 to 1.3 GeV2 and W from threshold up to 2.1 GeV and were compared to existing theoretical calculations. The polarized structure function is sensitive to the interferences between various resonant amplitudes, as well as to resonant and non-resonant amplitudes. This measurement is essential for understanding the structure of nucleons and searching for previously undetected nucleon excited states (resonances) predicted by quark models. The W dependence of the σ LT′ in the kinematic regions dominated by s and u channel exchange (cos qcmk = −0.50, −0.167, 0.167) indicated possible resonance structures not predicted by theoretical calculations. The σLT ′ behavior around W = 1.875 GeV could be the signature of a resonance predicted by the quark models and possibly seen in photoproduction. In the very forward angles where the reaction is dominated by the t-channel, the average σLT ′ was zero. There was no indication of the interference between resonances or resonant and non-resonant amplitudes. This might be indicating the dominance of a single t-channel exchange. Study of the sensitivity of the fifth structure function data to the resonance around 1900 MeV showed that these data were highly sensitive to the various assumptions of the models for the quantum number of this resonance. This project was part of a larger CLAS program to measure cross sections and polarization observables for kaon electroproduction in the nucleon resonance region. ^

Coherent rho meson electroproduction off deuteron

QCD predicts Color Transparency (CT), which refers to nuclear medium becoming transparent to a small color neutral object produced in high momentum transfer reactions, due to reduced strong interaction. Despite several studies at BNL, SLAC, FNAL, DESY and Jefferson Lab, a definitive signal for CT still remains elusive. In this dissertation, we present the results of a new study at Jefferson Lab motivated by theoretical calculations that suggest fully exclusive measurement of coherent rho meson electroproduction off the deuteron is a favorable channel for studying CT. Vector meson production has a large cross section at high energies, and the deuteron is the best understood and simplest nuclear system. Exclusivity allows the production and propagation to be controlled separately by controlling Q 2, lf (formation length), lc (coherence length) and t. This control is important as the rapid expansion of small objects increases their interaction probability and masks CT. The CT signal is investigated in a ratio of cross sections at high t (where re-scattering is significant) to low t (where single nucleon reactions dominate). The results are presented over a Q2 range of 1 to 3 GeV2 based on the data taken with beam energy of 6 GeV.

Spectroscopy of Electroproduced Light to Medium Mass Lambda Hypernuclei

The E01-011 experiment at Jefferson Laboratory (JLab) studied light-to-medium mass Λ hypernuclei via the AZ + e → [special characters omitted] + e' + K+ electroproduction reaction. Precise measurement of hypernuclear ground state masses and excitation energies provides information about the nature of hyperon-nucleon interactions. Until recently, hypernuclei were studied at accelerator facilities with intense π+ and K- meson beams. The poor quality of these beams limited the resolution of the hypernuclear excitation energy spectra to about 1.5 MeV (FWHM). This resolution is not sufficient for resolving the rich structure observed in the excitation spectra. By using a high quality electron beam and employing a new high resolution spectrometer system, this study aims to improve the resolution to a few hundred keV with an absolute precision of about 100 keV for excitation energies. In this work the high-resolution excitation spectra of [special characters omitted], and [special characters omitted] hypernuclei are presented. In an attempt to emphasize the presence of the core-excited states we introduced a novel likelihood approach to particle identification (PID) to serve as an alternative to the commonly used standard hard-cut PID. The new method resulted in almost identical missing mass spectra as obtained by the standard approach. An energy resolution of approximately 400–500 keV (FWHM) has been achieved, an unprecedented value in hypernuclear reaction spectroscopy. For [special characters omitted] the core-excited configuration has been clearly observed with significant statistics. The embedded Λ hyperon increases the excitation energies of the 11B nuclear core by 0.5–1 MeV. The [special characters omitted] spectrum has been observed with significant statistics for the first time. The ground state is bound deeper by roughly 400 keV than currently predicted by theory. Indication for the core-excited doublet, which is unbound in the core itself, is observed. The measurement of [special characters omitted] provides the first study of a d-shell hypernucleus with sub-MeV resolution. Discrepancies of up to 2 MeV between measured and theoretically predicted binding energies are found. Similar disagreement exists when comparing to the [special characters omitted] mirror hypernucleus. Also the core-excited structure observed between the major s-, p- and d-shell Λ orbits is not consistent with the available theoretical calculations. In conclusion, the discrepancies found in this study will provide valuable input for the further development of theoretical models.

QCD structure of nuclear interactions

The research presented in this dissertation investigated selected processes involving baryons and nuclei in hard scattering reactions. These processes are characterized by the production of particles with large energies and transverse momenta. Through these processes, this work explored both, the constituent (quark) structure of baryons (specifically nucleons and Δ-Isobars), and the mechanisms through which the interactions between these constituents ultimately control the selected reactions. The first of such reactions is the hard nucleon-nucleon elastic scattering, which was studied here considering the quark exchange between the nucleons to be the dominant mechanism of interaction in the constituent picture. In particular, it was found that an angular asymmetry exhibited by proton-neutron elastic scattering data is explained within this framework if a quark-diquark picture dominates the nucleon’s structure instead of a more traditional SU(6) three quarks picture. The latter yields an asymmetry around 90o center of mass scattering with a sign opposite to what is experimentally observed. The second process is the hard breakup by a photon of a nucleon-nucleon system in light nuclei. Proton-proton (pp) and proton-neutron (pn) breakup in 3He, and ΔΔ-isobars production in deuteron breakup were analyzed in the hard rescattering model (HRM), which in conjunction with the quark interchange mechanism provides a Quantum Chromodynamics (QCD) description of the reaction. Through the HRM, cross sections for both channels in 3He photodisintegration were computed without the need of a fitting parameter. The results presented here for pp breakup show excellent agreement with recent experimental data. In ΔΔ-isobars production in deuteron breakup, HRM angular distributions for the two ΔΔ channels were compared to the pn channel and to each other. An important prediction fromthis study is that the Δ++Δ- channel consistently dominates Δ+Δ0, which is in contrast with models that unlike the HRM consider a ΔΔ system in the initial state of the interaction. For such models both channels should have the same strength. These results are important in developing a QCD description of the atomic nucleus.

A precise measurement of the two -photon exchange effect

The two-photon exchange phenomenon is believed to be responsible for the discrepancy observed between the ratio of proton electric and magnetic form factors, measured by the Rosenbluth and polarization transfer methods. This disagreement is about a factor of three at Q 2 of 5.6 GeV2. The precise knowledge of the proton form factors is of critical importance in understanding the structure of this nucleon. The theoretical models that estimate the size of the two-photon exchange (TPE) radiative correction are poorly constrained. This factor was found to be directly measurable by taking the ratio of the electron-proton and positron-proton elastic scattering cross sections, as the TPE effect changes sign with respect to the charge of the incident particle. A test run of a modified beamline has been conducted with the CEBAF Large Acceptance Spectrometer (CLAS) at Thomas Jefferson National Accelerator Facility. This test run demonstrated the feasibility of producing a mixed electron/positron beam of good quality. Extensive simulations performed prior to the run were used to reduce the background rate that limits the production luminosity. A 3.3 GeV primary electron beam was used that resulted in an average secondary lepton beam of 1 GeV. As a result, the elastic scattering data of both lepton types were obtained at scattering angles up to 40 degrees for Q2 up to 1.5 GeV2. The cross section ratio displayed an &epsis; dependence that was Q2 dependent at smaller Q2 limits. The magnitude of the average ratio as a function of &epsis; was consistent with the previous measurements, and the elastic (Blunden) model to within the experimental uncertainties. Ultimately, higher luminosity is needed to extend the data range to lower &epsis; where the TPE effect is predicted to be largest.

Proton Form Factor Puzzle and the CEBAF Large Acceptance Spectrometer (CLAS) two-photon exchange experiment

The electromagnetic form factors are the most fundamental observables that encode information about the internal structure of the nucleon. The electric (GE) and the magnetic ( GM) form factors contain information about the spatial distribution of the charge and magnetization inside the nucleon. A significant discrepancy exists between the Rosenbluth and the polarization transfer measurements of the electromagnetic form factors of the proton. One possible explanation for the discrepancy is the contributions of two-photon exchange (TPE) effects. Theoretical calculations estimating the magnitude of the TPE effect are highly model dependent, and limited experimental evidence for such effects exists. Experimentally, the TPE effect can be measured by comparing the ratio of positron-proton elastic scattering cross section to that of the electron-proton [R = σ(e +p)/σ(e+p)]. The ratio R was measured over a wide range of kinematics, utilizing a 5.6 GeV primary electron beam produced by the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. This dissertation explored dependence of R on kinematic variables such as squared four-momentum transfer (Q2) and the virtual photon polarization parameter (&epsis;). A mixed electron-positron beam was produced from the primary electron beam in experimental Hall B. The mixed beam was scattered from a liquid hydrogen (LH2) target. Both the scattered lepton and the recoil proton were detected by the CEBAF Large Acceptance Spectrometer (CLAS). The elastic events were then identified by using elastic scattering kinematics. This work extracted the Q2 dependence of R at high &epsis;(&epsis; > 0.8) and the $&epsis; dependence of R at ⟨Q 2⟩ approx 0.85 GeV2. In these kinematics, our data confirm the validity of the hadronic calculations of the TPE effect by Blunden, Melnitchouk, and Tjon. This hadronic TPE effect, with additional corrections contributed by higher excitations of the intermediate state nucleon, largely reconciles the Rosenbluth and the polarization transfer measurements of the electromagnetic form factors.

Experimental deuteron momentum distributions with reduced final state interactions

This dissertation presents a study of the D( e, e′p)n reaction carried out at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for a set of fixed values of four-momentum transfer Q 2 = 2.1 and 0.8 (GeV/c)2 and for missing momenta pm ranging from pm = 0.03 to pm = 0.65 GeV/c. The analysis resulted in the determination of absolute D(e,e′ p)n cross sections as a function of the recoiling neutron momentum and it's scattering angle with respect to the momentum transfer [vector] q. The angular distribution was compared to various modern theoretical predictions that also included final state interactions. The data confirmed the theoretical prediction of a strong anisotropy of final state interaction contributions at Q2 of 2.1 (GeV/c)2 while at the lower Q2 value, the anisotropy was much less pronounced. At Q2 of 0.8 (GeV/c)2, theories show a large disagreement with the experimental results. The experimental momentum distribution of the bound proton inside the deuteron has been determined for the first time at a set of fixed neutron recoil angles. The momentum distribution is directly related to the ground state wave function of the deuteron in momentum space. The high momentum part of this wave function plays a crucial role in understanding the short-range part of the nucleon-nucleon force. At Q2 = 2.1 (GeV/c)2, the momentum distribution determined at small neutron recoil angles is much less affected by FSI compared to a recoil angle of 75°. In contrast, at Q2 = 0.8 (GeV/c)2 there seems to be no region with reduced FSI for larger missing momenta. Besides the statistical errors, systematic errors of about 5–6 % were included in the final results in order to account for normalization uncertainties and uncertainties in the determi- nation of kinematic veriables. The measurements were carried out using an electron beam energy of 2.8 and 4.7 GeV with beam currents between 10 to 100 &mgr; A. The scattered electrons and the ejected protons originated from a 15cm long liquid deuterium target, and were detected in conicidence with the two high resolution spectrometers of Hall A at Jefferson Lab.^

Estudo in silico das interações da protease NS3-NS2B de DENV-2 com o inibidor peptídico Bz-nKRR-H com finalidades terapêuticas

Dengue virus is an important patogen that causes Dengue desease in all world, and belongs to Flavivirus gender. The virus consists of enveloped RNA with a single strand positive sense, 11Kb genome. The RNA is translated into a polyprotein precursor, wich is cleaved into 3 structural proteins (C, prM e E) and 7 non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B e NS5). The NS3 is a multifunctional protein, that besides to promote the polyprotein precursor cleavage, also have NTPase, helicase and RTPase activity. The NS3 needs a hydrophilic segment of 40 residues from the transmembrane NS2B protein (who acts like cofator) to realize this functions. Actually, there's no vacines available on the market, and the treatment are just symptomatic. The tetrapeptide inhibitor Bz-Nle-Lys-Arg-Arg-H (Ki de 5,8-7,0 M) was showed as a potent inhibitor μ for NS3prot in Dengue virus. That is a inteligent alternative to treat the dengue desease. The present work aimed analyse the interactions of the ligand bounded to the activity site to provid a clear and depth vision of that interaction. For this purpouse, it was conducted an in silico study, by using quantum mechanical calculations based on Density Functional Theory (DFT), with Generalized Gradient approximation (GGA) to describe the effects of exchange and correlation. The interaction energy of each amino acid belonging to the binding site to the ligand was calculated the using the method of molecular fragmentation with conjugated caps (MFCC). Besides energy, we calculated the distances, types of molecular interactions and atomic groups involved. The theoretical models used were satisfactory and show a more accurate description when the dielectric constant = 20 ε and 80 was used. The results demonstrate that the interaction energy of the system reached convergence at 13.5 A. Within a radius of 13,5A the most important residues were identified. Met49, Met84 and Asp81 perform interactions of hydrogen with the ligant. The Asp79 and Asp75 residues present high energy of attraction. Arg54, Arg85 and Lys 131 perform hydrogen interactions with the ligand, however, appear in BIRD graph having high repulsion energy with the inhibitor. The data also emphasizes the importance of residue Tyr161 and the involvement of the catalytic triad composed by Asp75, His51 and Ser135

Ambiente de inovação no Laboratório de Inovação Tecnológica em Saúde – LAIS/UFRN: mapeamento, interações e gerenciamento

Innovation has become an increasingly central issue of great reputation, not only in literature but also in management practices, becoming a strategic issue for managers of organizations. Allied to this, there is a high degree of competitiveness on the market, which contributes to the complexity of decision making, since managers need to maintain a continuous cycle of renewal processes and products. Thus, market pressures for new alternatives encourage innovation within organizations as a foundation for culture change in pursuit of survival and increased competitiveness, making it essential to know the factors that promote the advancement of organizational environments targeted innovation. Confirming this view, Bouchikhi and Kimberly (2001) symbolically expressed the idea with two statements: (1) companies need to innovate to survive, otherwise they die; and (2) the wide recognition of this need, as well as the difficulty to encourage and support innovation and entrepreneurship in business, has generated a mini-industry research and consulting in management focused on these topics. This study is characterized as descriptive with qualitative and quantitative methods. As for the planning of the research, it was decided to bibliographical research and the case study. The research, developed here, is meant to examine the organizational environment of a laboratory focused on technological innovation in health, which is a reference in research and technology of Rio Grande do Norte, and ensure that it presents opportunities to develop innovations. Therefore, the technologies developed by the Laboratório de Inovação Tecnológica em Saúde - LAIS/UFRN were mapped and then a questionnaire with the stakeholders of LAIS/UFRN was applied. This questionnaire is closed and Likert scale. As a result, it follows that the dimensions 1, 6, 7 and 8 are the most influential to form an innovative environment at LAIS.

Interações da trancinolona com ciclodextrinas em sistemas multicomponentes

Triamcinolone is a relevant anti-inflammatory costicosteroid drug, used mainly by injectable suspensions due its poor water solubility. The association of triamcinolone with cyclodextrins and co-solvents (triethanolamine TEA and N-methylpirrolidone NMP) was held to solubilize the drug and explain the involved interactions. Phase-solubility diagrams showed that triamcinolone was solubilized forming incredible stable complexes with cyclodextrins, in which bests results were observed applying randomyl-methylated-beta-cyclodextrin (RMβCD) (161 fold on increased solubility). The co-solvents TEA and NMP also enhanced drug solubility 1.4 and 6.7 fold, respectively. The association of both co-solvents with CDs seems decreased complexation stability, but enables higher amount of uncomplexed drug. Experimental magnetic resonance 2D-ROESY and theoretical molecular modeling studies demonstrated TRI-CDs interactions and elucidated the structure of formed complex, which occurred due to the inclusion of ring A of TRI on CDs cavity. Physicochemical aspects of solid binary and ternary complexes prepared by spray drying were assessed by using FTIR, X-ray diffraction and SEM photographs. Dissolution studies showed that binary and ternary associations presented higher dissolution efficacy in detrimental to pure drug system. In addition, the ternary complex containing TEA and RMβCD allowed drug dissolution faster than binary complex with RMβCD. Therefore, given the higher solubility and drug dissolution rate, binary and ternary complexes are new raw materials with great potential for pharmaceuticals containing triamcinolone.

"Quem sou eu?": uma (re)construção do sujeito por meio da narrativa autobiográfica - proposta didática com um olhar nas interações em sala de aula

As we are aware, the classroom is emerging as a continuous build learning experiences and environment, however, for students also it functions as a place also to be due to socializing with friends. However, not always these elements complement each other, so as harmoniously as we are aware that there are many difficulties, both in the act of learning as in interpersonal relations between them. From this, we understand that it is for the school to seek ways to contemplate such issues so that they feel inserted both with regard to this learning as well as being able to interact with themselves and with others, in a participatory manner, to live well socially. Thus, we find ourselves facing a similar situation with a 9th grade class where the students had certain limitations to have a good relationship with one another, causing thus problems in learning. On the other hand, this difficulty as affectively interact with each other, also, was increased by the difficulty that some students had to speak for themselves and to show their feelings and emotions, getting even more difficult this interaction at school. Thus, we found ourselves obliged to act immediately and need to bring about change in this picture. So it came out the idea of the application of an intervening action which started taking shapefrom a pedagogical project that we developed in other classes in previous years, this time adapted to the situation experienced by the group. The project, framed in the qualitative research and characterized from the action research approach took shape, and elected as its main objective to seek possible alternatives to develop the communicative competence of students, which is why we invest in exercise oral communication (speaking and listening) in order to promote the use of language, the interpersonal involvement facilitating thus their participation both in the classroom and in social life. To fulfill this goal, we set out to develop a didactic book whose support materialized through the autobiographical narrative (molded in writing production) and worked along a structured instructional sequence in three distinctstages that dialogued with each other. Therefore, we base our study from the socio-historical conception and dialogue proposed by Bakhtin in line with the sociodiscursivo interactionism of Bronckart and resort to other scholars as Dolz and Schneuwly, Marcuschi among others. The development of all stages of the project not only has had an immediate effect on what we proposed ourselves as also yielded us very gratifying moments reinforcing to us that the classroom environment goes far beyond the fact ministering content. And that work with orality, with views on affective interaction of these students resulted in a project, so to speak, exciting.

Mapeamento, interações e gerenciamento do fluxo de pacientes da Maternidade Escola Januário Cicco - MEJC

The process mapping is an important tool in the management of organizations, allowing better levels of productivity, quality and reciprocity concerning the implementation and decision-making. It benefits in a clear way the process organization and assures the manager a macro vision of the system. In this sense, the objective of this study is to describe the mapping process as it occurs in the Januario Cicco Maternity School–MEJC. The bibliographic and descriptive research included interviews, observations and researches in many databases. The study analyzed the limiting points of the detected flow trying to find a better comprehension of the flow of patients in the maternity in order to offer the gestors the information necessary to improve the quality of the assistance as well as a general view of the flow of patients and any change detected there. As a result, we believe that the process mapping may become a relevant factor to the organizational management of MEJC, in view that it is an element that can contribute to ease up the management of information studied, considering that the perfect change of information inside a complex system will produce improvements in all spheres of this institution.

Interações magnéticas e elétricas em GaMnAs

In this paper, we will address together the magnetic and electrical properties of a particular semiconductor, the GaMnAs. The treatment will be done analytically in the first part of the work, according to the computational method for simulation of physical systems through the implementation of the expressions obtained in the first part. All study of magnetic contribution will be made using an interaction Kondo type, using an approach by Green functions. The electrical part, which consists of the Coulomb interactions between carriers and Mn ions, will be treated within the approach of multiple scattering. The implementation of the proposed method will calculate the Green functions converged as multiple scattering solution and use them as a starting point for the calculation of the effective magnetic interactions between Mn ions mediated charge carriers. The concentration parameters were varied for Mn ions and carriers as well. The combination of these two parameters can lead to insulating, metal samples with carriers in Fermi level to low or high mobility. As a result a correlation between the obtained carrier mobility and the strength of magnetic interaction. The greater mobility, the greater the intensity of the interaction.

Manipulação gênica do protozoário Neospora caninum como ferramenta para o estudo das interações parasito-hospedeiro

Neospora caninum is an obligate intracellular parasite classified in the phylum Apicomplexa, characterized by the presence of the apical complex composed by micronemes proteins, rhoptries and dense granules, used by parasite during the adhesion and invasion process of the host cell. This is the mean event in infection pathogenesis generated by N. caninum and other parasites from the phylum Apicomplexa, promoting influence in the parasite biology and the interface between the parasite and its host. Therefore, molecular tools have been developed in order to identify and characterize these possible virulence factors. Thus, the present study sought to establish a specific system of genetic manipulation of N. caninum, searching for the improvement of the genetics manipulation of this parasite. So, we developed genetically depleted N. caninum to Rop9 rhoptry using the pU6-Universal CRISPR-Cas9 plasmid of T. gondii modified by the insertion of Ku80. The Rop9 depleted parasite showed important during initial phase of invasion and replication of the parasite, however it was not characterized as a potential virulence fator for N. caninum. Furthermore, T. gondii proteins were expressed in N. caninum by the use of specific vectors for this parasite, showing an heterologous system for the study of Toxoplasma proteins, due to the fact that Gra15 or Gra24 of type II T. gondii and Rop16 of type I T. gondii were expressed in N. caninum tachyzoites in a stable way and keept its biological phenotype, as already presented the former parasite, that naturaly expresses these proteins. In addition, it was observed that N. caninum induced an inflammasome activation through NLRP3, ASC and Caspase-1. IL-1R/MyD88 demonstrated an indirect pathway in the control of parasite replication. Furthermore, it was observed that this activation is dependent of the potassium efflux and that different strains of N. caninum keep this activation profile. However, T. gondii strains block this activation, making necessary a prior signal in order to active the inflamosome pathway. Type I T. gondii Rop16 was identified as responsible for blocking this activation, in a dependent way to the STAT3 activation. Therefore, the development of molecular tools and their application in N. caninum may prove to be useful to identify and characterize virulent factors involved in the pathogenesis by these two protozoans.

Refletindo sobre a Prática Pedagógica em Educação de Infância: das interações entre pares ao projeto das abelhas

O presente relatório, realizado no âmbito da Prática de Ensino Supervisionada do Mestrado em Educação Pré-Escolar, é composto por duas partes: Dimensão Reflexiva e Dimensão Investigativa. Na Dimensão Reflexiva é apresentada uma reflexão sobre a prática em contexto de creche e de jardim de infância. Nesta dimensão são focados os aspetos que considerei mais significativos, como as minhas aprendizagens e dúvidas ou o que é ser educador de infância. A Dimensão Investigativa refere-se a um ensaio investigativo realizado no contexto de creche, com a finalidade de saber quais as interações que as crianças com idades compreendidas entre os 12 e os 24 meses estabelecem entre si, no momento de brincadeira livre, ao redor e dentro da casinha. Seguindo uma metodologia qualitativa, apresentam-se os participantes, os instrumentos de recolha de dados e os procedimentos, bem como os resultados e a sua análise. Os resultados evidenciam que as crianças estabelecem, predominantemente, interações não-verbais com os seus pares, ideia corroborada por Alexandre e Vieira (2004). Investigando com as crianças, no contexto de jardim de infância, revela-se o projeto desenvolvido sobre as abelhas, seguindo a metodologia de trabalho de projeto. Com as crianças descobrimos que as abelhas têm seis patas, que recolhem o pólen das flores, que vivem numa colmeia e que têm três tamanhos diferentes.