Um estudo sobre os processos de aprendizagem dos trabalhadores que não exercem funções gerencial

Os processos de aprendizagem que ocorrem no local de trabalho constituem o foco deste estudo. O objetivo é identificar e analisar os processos de aprendizagem no local de trabalho de indivíduos que não exercem a função gerencial. No plano teórico, adota-se a abordagem social da aprendizagem organizacional. No plano metodológico, realiza-se um estudo qualitativo básico junto a duas equipes administrativas pertencentes a uma empresa de fertilizantes químicos. Os resultados evidenciam a importância dos processos informais de aprendizagem a partir das contribuições das experiências obtidas no contexto de trabalho dos pesquisados. Identificaram-se os objetivos, aspectos facilitadores, obstáculos e resultados dos processos de aprendizagem. A relevância da interação social, do aprender pela prática e do contexto organizacional foi destaque nos processos de aprendizagem. O estudo adiciona subsídios aos profissionais de recursos humanos na elaboração de uma análise crítica sobre as atuais práticas e políticas de desenvolvimento dos indivíduos nas organizações.The learning processes that occur at work place constitute the focus of the study. The goal is to identify and to analyze the learning processes at work place of individuals that don’t exercise the managerial function. At the theoretical level a social perspective of organizational learning is adopted. At the methodological level a basic qualitative study was carried out in two teams of a company of chemical fertilizers. The results evidence the importance of the informal processes of learning through the contributions of the experiences obtained in the work context. It was identified the objectives, opportunities, obstacles and the results of the processes of learning. The relevance of the social interaction, of the learning by doing and of the organizational context were highlights in the learning processes. The study adds subsidies to the professionals of the area of Human Resources in the elaboration of a critical analysis about the current practices and politics of personnel development in organizations

Proton irradiation of DNA nucleosides in the gas phase

International audienceThe four DNA nucleosides guanosine, adenosine, cytidine and thymidine have been produced in the gas phase by a laser thermal desorption source, and irradiated by a beam of protons with 5 keV kinetic energy. The molecular ions as well as energetic neutrals formed have been analyzed by mass spectrometry in order to shed light on the ionization and fragmentation processes triggered by proton collision. A range of 8-20 eV has been estimated for the binding energy of the electron captured by the proton. Glycosidic bond cleavage between the base and sugar has been observed with a high probability for all nucleosides, resulting in predominantly intact base ions for guanosine, adenosine, and cytidine but not for thymidine where intact sugar ions are dominant. This behavior is influenced by the ionization energies of the nucleobases (G < A < C < T), which seems to determine the localization of the charge following the initial ionization. This charge transfer process can also be inferred from the production of protonated base ions, which have a similar dependence on the base ionization potential. Other dissociation pathways have also been identified, including further fragmentation of the base and sugar moieties for thymidine and guanosine, respectively, and partial breakup of the sugar ring without glycosidic bond cleavage mainly for adenosine and cytidine. These results show that charge localization following ionization by proton irradiation is important in determining dissociation pathways of isolated nucleosides, which could in turn influence direct radiation damage in DNA

Detection limits of organic compounds achievable with intense, short-pulse lasers

Many organic molecules have strong absorption bands which can be accessed by ultraviolet short pulse lasers to produce efficient ionization. This resonant multiphoton ionization scheme has already been exploited as an ionization source in time-of-flight mass spectrometers used for environmental trace analysis. In the present work we quantify the ultimate potential of this technique by measuring absolute ion yields produced from the interaction of 267 nm femtosecond laser pulses with the organic molecules indole and toluene, and gases Xe, N2 and O2. Using multiphoton ionization cross sections extracted from these results, we show that the laser pulse parameters required for real-time detection of aromatic molecules at concentrations of one part per trillion in air and a limit of detection of a few attomoles are achievable with presently available commercial laser systems. The potential applications for the analysis of human breath, blood and tissue samples are discussed

Ultraviolet relaxation dynamics in uracil: Time-resolved photoion yield studies using a laser-based thermal desorption source

Wavelength-dependent measurements of the RNA base uracil, undertaken with nanosecond ultraviolet laser pulses, have previously identified a fragment at m/z = 84 (corresponding to the C3H4N2O+ ion) at excitation wavelengths ≤232 nm. This has been interpreted as a possible signature of a theoretically predicted ultrafast ring-opening occurring on a neutral excited state potential energy surface. To further investigate the dynamics of this mechanism, and also the non-adiabatic dynamics operating more generally in uracil, we have used a newly built ultra-high vacuum spectrometer incorporating a laser-based thermal desorption source to perform time-resolved ion-yield measurements at pump wavelengths of 267 nm, 220 nm, and 200 nm. We also report complementary data obtained for the related species 2-thiouracil following 267 nm excitation. Where direct comparisons can be made (267 nm), our findings are in good agreement with the previously reported measurements conducted on these systems using cold molecular beams, demonstrating that the role of initial internal energy on the excited state dynamics is negligible. Our 220 nm and 200 nm data also represent the first reported ultrafast study of uracil at pump wavelengths 3(1ππ*) state. These measurements do not, however, provide any evidence for the appearance of the m/z = 84 fragment within the first few hundred picoseconds following excitation. This key finding indicates that the detection of this specific species in previous nanosecond work is not directly related to an ultrafast ring-opening process. An alternative excited state process, operating on a more extended time scale, remains an open possibility

A agência a partir da teoria do ator-rede: reflexões e contribuições para as pesquisas em administração

A Teoria Ator-Rede (TAR) provoca os leitores a desenvolverem diferentes olhares, a partir da redefinição da noção de social, que retorna às suas raízes, possibilitando novamente o estabelecimento de conexões. Para Latour (2005), a sociedade, longe de ser o contexto no qual todas as coisas são enquadradas, é interpretada como um dos inúmeros elementos que se conectam e, assim, para Law (1992), é provável que a maior parte de nossas relações seja mediada pela materialidade. O que seria das organizações se não fosse a presença da materialidade? Dentre as várias noções e conceitos abordados pela TAR, optamos por debater a noção de agência dos atores (actantes), que busca a não dicotomização entre os elementos humanos e não humanos. Nosso propósito é identificar e discutir contribuições da TAR para os estudos organizacionais no que se refere à agência relacionada ao não humano, sem menosprezar o humano e com um olhar atento às relações. Assim, a forma que encontramos para “mostrar a agência dos não humanos” foi evidenciar (por meio das descrições e análises de pesquisa) suas relações com os humanos e o quanto essas relações constituem um ao outro, por meio de trechos de dois estudos desenvolvidos no campo da administração. A TAR ajuda, portanto, a atribuir as ações a um número maior de actantes. Discutir questões sobre agência está diretamente relacionado ao estabelecimento de conexões que a TAR preconiza. É nas conexões de elementos heterogêneos que a agência torna-se “capturável” ao pesquisado

Alterações no estado nutricional em adolescentes sobreviventes de leucemias e linfomas

Objective To examine the changes in the nutritional status of adolescents aged 10-19 years after a minimum 12 months interval following oncological treatment for leukemias and lymphomas. Methods Longitudinal design quantitative study conducted at Hospital de Clínicas, Porto Alegre. Adolescents aged 10-19 years after a minimum 12 months interval following oncological treatment for leukemias and lymphomas were included. The measures of weight, height, brachial circumference, triceps skinfold thickness, arm muscle circumference and abdominal circumference were collected. Results The sample comprised 50 adolescents who had survived leukemias and lymphomas. In the follow up 38% of the patients were classified as overweight according to the body mass index for their age. There was a significant increase in body mass index for age between the beginning and the end of treatment and follow up (p=0.013) in female individuals, compared to males. The results indicate a reduction in the Z-score means of height for age, with significant differences between the beginning of treatment and follow up (p=0.016); and end of treatment and follow up (p=0.006) in patients of both genders Conclusion The anthropometric indicators show an important frequency of excess weight and increased tricipital skinfold, as well as a significant increase of the body mass index for age and also a growth deficit among the survivors.Objetivo Verificar as alterações no estado nutricional em adolescentes de 10-19 anos, observadas após 12 meses, no mínimo, da conclusão de tratamento oncológico de leucemias e linfomas. Métodos Trata-se de estudo quantitativo de delineamento longitudinal realizado no Hospital de Clínicas de Porto Alegre. Foram incluídos adolescentes de 10-19 anos, que haviam concluído tratamento oncológico para leucemias e linfomas há no mínimo doze meses. Foram coletadas as medidas de peso, estatura, circunferência braquial, dobra cutânea tricipital, circunferência muscular do braço e circunferência abdominal. Resultados A amostra foi constituída por cinquenta adolescentes sobreviventes de leucemias e linfomas. No follow up, 38% dos pacientes foram classificados como excesso de peso de acordo com o índice de massa corporal para a idade. Houve um aumento significativo no índice de massa corporal para a idade, ocorrida entre o início do tratamento, seu fim e follow up (p=0,013) nos indivíduos do sexo feminino, quando comparados a indivíduos do sexo masculino. Os resultados apontam uma diminuição nas médias de Escore-Z de estatura para a idade, com diferenças significativas entre o início do tratamento e follow up (p=0,016) e entre término do tratamento e follow up (p=0,006), em pacientes de ambos os sexos. Conclusão Os indicadores antropométricos demonstram uma frequência importante de excesso de peso e aumento da dobra cutânea tricipital, um aumento significativo do índice de massa corporal para a idade, bem como um deficit de crescimento entre os sobreviventes

Fluid modeling of pressure anisotropy effects in a magnetized plasma

It is well known that in many cases the dynamics of a magnetized plasma involve a very large number of scale lengths and frequencies which, even if separated by several orders of magnitudes, are intrinsically connected one each other. Such a system cannot be studied by solving numerically the whole dynamics, but it is necessary to make appropriate approximations in order to simplify the analysis and work out a model able to capture the main features that characterize the evolution of the system. Therefore, a suitable fluid modeling, capable of including the main kinetic effects, is of primary importance for the description of space and laboratory plasmas. Moreover, space and laboratory plasma are characterized by the presence of a background magnetic field which introduces conditions for a more complex dynamics, globally modifying the symmetry of the system. From a theoretical point of view, the set of fluid equations cannot be closed by means of the usual adiabatic relation on the pressure term, because of the different behaviour along or perpendicular to the magnetic field. Therefore, the pressure tensor cannot be longer assumed as isotropic. An appropriate alternative is to adopt a model based on the double adiabatic invariants of particle motion. This theory, proposed by Chew, Goldberger and Low (CGL), gives two conservative equations for the parallel and the perpendicular pressures, allowing the system to follow a different evolution for each component. Depending if the level of pressure anisotropy overcomes some given threshold, the magnetized plasma becomes unstable under two important anisotropy instabilities: the firehose instability (FHI) and the mirror instability (MI). These instabilities tend to compensate the pressure unbalance changing the equilibrium configuration of the system. The development of a pressure anisotropy is a relevant process which may be involved in many problems of space and laboratory plasmas. The phenomenon analysed in this work is the non-linear evolution of vortices generated by the Kelvin-Helmholtz instability (KHI), which occurs in the solar wind-magnetosphere interaction. Multi-spacecraft measurements have provided unambiguous evidence for rolled-up vortices as well as observed boundary layer features resulting from the suggested KH instability. This important mechanism is supposed to be the best candidate for the formation of a mixing layer along the low latitude flanks of the magnetosphere during the northwards conditions (when the solar-wind field and geomagnetic field are parallel), providing an efficient way for the solar wind plasma to enter the magnetospheric region. Indeed, the magnetic field line reconnection, which is the dominant process in the southwards conditions, cannot explain experimental data in the opposite northwards configuration, when the mixing process is larger than expected. The vortex motion is in turn the source of secondary magneto-fluid instabilities, e.g. magnetic reconnection, KH, Rayleigh-Taylor. The characteristic time scales of these secondary instabilities have a crucial role in the competition with the vortex pairing hydrodynamic process, driving a disruptive process inside and outside the vortices. During this non-linear dynamics, the firehose instability may have an important role in the evolution of the magnetic field configuration, considerably increasing the small in-plane component and bringing the system in a more complex turbolent state. The present work has the purpose to study the development of the pressure anisotropy during the formation of vortex structures driven by an initial shear velocity configuration and their non-linear evolution. The simplified 2D dynamics is defined by the velocity field and the perpendicular inhomogeneous direction. The shear velocity length and the magnetofast Mach number characterize the vortex motion. Several initial configurations, concerning the subsonic and supersonic regimes and the presence of a density gradient, have been investigated during the linear KHI development and during the evolution of its non-linear stage. More attention has been given to the compressibility property connected to the pressure anisotropy evolution. In particular, it has been observed that in the supersonic regime the pressure anisotropy is large enough to be able to drive the FH instability. Moreover, its linear growth can occur on a much smaller time-scale compared to the vortex dynamics, competiting with the pairing and the secondary instabilities processes. Finally, in this work we have also started to consider the full 3D system. In particular, we have focused our attention on the development of the FH instability. The preliminary work is limited to the analysis of the linear growth rate of the FH instability assuming as initial state several anisotropy conditions

Ultrafast dynamics in gas-phase building blocks of life

Ultrafast electron dynamics are responsible for the physical and chemical properties of molecular systems. They can induce variations in the local reactivity as well as in the nuclear arrangement, both of which ultimately determine the making and breaking of molecular bonds.This thesis presents pump-probe measurements of femtosecond (10−15 s) and attosecond (10−18 s) electron dynamics in biomolecular building blocks of DNA and proteins, namely nucleosides and aromatic amino acids, characterised by a large degree of stability due to their efficiency in converting electronic energy into vibrational energy within picosecond and sub-picosecond timescales. The study of the inherent properties of these molecules requires the removal of any possible influence of the surrounding environment, for instance represented by the introduction of solvents. The production of isolated molecular samples was achieved by laser induced thermal desorption technique, which was found to be capable of evaporating intact and neutral molecules and of generating an usable gas-phase target for spectrometric measurements.Low intensities of UV laser radiation are sufficient to access the electron wave-packet evolution from the first excited state of the analyte along the corresponding potential energy surfaces. In a bottom-up approach to investigate the photo-physical properties of DNA and peptide systems, the individual UV chromophores of these compounds have been studied up to now. The next step consists of studying de-excitation dynamics of larger building blocks, such as nucleosides and aromatic amino acids. The bonding of the sugar ring to the nuclebases, as well as of the glycine moiety to the aromatic chromophores was observed to facilitate and, in some cases, to speed up the relaxation process. These results are discussed in terms of alternative non-radiative deactivation channels opened up by the added units.At higher photon energies or intensities, electron motion and charge transfer can be studied by prompt removal of an electron from the highest occupied molecular orbital. These dynamics are fundamental in understanding the variation of local reactivity and, hence, to predict the possible reaction channels promoted by further photo-absorption. In aromatic amino acids, the ring structures are strongly involved in internal conversion processes occurring within tens of femtoseconds. Furthermore, fragmentation patterns of nucleosides produced by UV and IR irradiation gave clear evidence of the presence of an ultrafast base/sugar charge transfer in deoxy-thymidine, whereas it was less probable or unlikely in the other nucleosides due to less favourable energetics.Much faster dynamics can be initiated by attosecond XUV irradiation, where the superposition of many electronic states produces pure electron motion preceding any nuclear rearrangement. Cutting-edge laser technology has made possible the observation of ultrafast charge migration in tryptophan by looking at the doubly charged immonium ion channel. The signal modulation with period of 4 fs corresponds to theelectron beating between the amino group and the side-chain indole. Oscillation frequency and coherence of this phenomenon are discussed in comparison with the previous experiment in phenylalanine. These results represent the first ever time-resolved measurements of coherent electron motion in complex biomolecules, which pave the way for steering electron dynamics and controlling molecular reactivity

From translation to enactment : contributions of the Actor-Network Theory to the processual approach to organizations

Na área da Administração, em especial nos Estudos Organizacionais (EO), a Teoria Ator-Rede (TAR) tem sido considerada parte de um movimento que almeja sair da ênfase funcional da organização e buscar o estudo de processos e práticas do organizar – a abordagem processual das organizações. Entretanto, as críticas à TAR levaram alguns autores a buscar superá-las por meio de torções analíticas em relação a certos conceitos. Uma dessas “torções” envolveu o conceito de translação e a inclusão do conceito de enactment. Este artigo discute ambas as noções com o auxílio de dois estudos desenvolvidos com base nesses conceitos, para indicar que a escolha do enactment traz consigo uma visão processual distinta da apresentada na translação. O conceito de translação trata do predominante e enfatiza a compreensão de como as redes de relações e os objetos tornam-se “estáveis”; já o enactar trabalha com a multiplicidade e a fluidez, onde o processo tem primazia sobre as coisas. Embora a proposta do termo enactment não busque enfrentar diretamente todas as críticas, ele contribui para que a TAR não assuma uma visão neutra nem mecânica em suas análises e descrições. O enactment apresenta a visão de organização como resultado e produto de processos contínuos e possibilita compreender que não se trata de dar certo ou não (sucesso ou fracasso), mas se trata da “produção” de realidades múltiplas ao realizarmos pesquisas em Administração com base na abordagem processual das organizações.In the area of Administration, especially in the Organizational Studies (OS), the Actor-Network Theory (ANT) has been regarded as part of a movement that aims to leave the functional emphasis of organization and pursue the study of process and practices of organizing – the processual approach to organizations. However, criticism to the ANT has led some authors to seek to overcome them through analytical twists concerning certain concepts. One of these “twists” involved the concept of translation and the inclusion of the concept of enactment. This article discusses both notions with the aid of two studies developed having these concepts as a basis, in order to indicate that the choice of enactment brings along a processual view different from that observed in translation. The concept of translation addresses the predominant and it emphasizes understanding how networks of relationships and objects become “stable”; in turn, enact works with multiplicity and fluidity, where the process takes precedence over things. Although the proposed term enactment does not seek to directly face all criticism, it contributes so that ANT does not take a neutral or mechanical view in its analyses and descriptions. Enactment has the view of organization as a result and product of continuous process and it allows understanding that this is not just working or not (success or failure), but it concerns the “production” of multiple realities when we conduct research in Administration having the processual approach to organizations as a basis

From translation to enactment : contributions of the Actor-Network Theory to the processual approach to organizations

Na área da Administração, em especial nos Estudos Organizacionais (EO), a Teoria Ator-Rede (TAR) tem sido considerada parte de um movimento que almeja sair da ênfase funcional da organização e buscar o estudo de processos e práticas do organizar – a abordagem processual das organizações. Entretanto, as críticas à TAR levaram alguns autores a buscar superá-las por meio de torções analíticas em relação a certos conceitos. Uma dessas “torções” envolveu o conceito de translação e a inclusão do conceito de enactment. Este artigo discute ambas as noções com o auxílio de dois estudos desenvolvidos com base nesses conceitos, para indicar que a escolha do enactment traz consigo uma visão processual distinta da apresentada na translação. O conceito de translação trata do predominante e enfatiza a compreensão de como as redes de relações e os objetos tornam-se “estáveis”; já o enactar trabalha com a multiplicidade e a fluidez, onde o processo tem primazia sobre as coisas. Embora a proposta do termo enactment não busque enfrentar diretamente todas as críticas, ele contribui para que a TAR não assuma uma visão neutra nem mecânica em suas análises e descrições. O enactment apresenta a visão de organização como resultado e produto de processos contínuos e possibilita compreender que não se trata de dar certo ou não (sucesso ou fracasso), mas se trata da “produção” de realidades múltiplas ao realizarmos pesquisas em Administração com base na abordagem processual das organizações.In the area of Administration, especially in the Organizational Studies (OS), the Actor-Network Theory (ANT) has been regarded as part of a movement that aims to leave the functional emphasis of organization and pursue the study of process and practices of organizing – the processual approach to organizations. However, criticism to the ANT has led some authors to seek to overcome them through analytical twists concerning certain concepts. One of these “twists” involved the concept of translation and the inclusion of the concept of enactment. This article discusses both notions with the aid of two studies developed having these concepts as a basis, in order to indicate that the choice of enactment brings along a processual view different from that observed in translation. The concept of translation addresses the predominant and it emphasizes understanding how networks of relationships and objects become “stable”; in turn, enact works with multiplicity and fluidity, where the process takes precedence over things. Although the proposed term enactment does not seek to directly face all criticism, it contributes so that ANT does not take a neutral or mechanical view in its analyses and descriptions. Enactment has the view of organization as a result and product of continuous process and it allows understanding that this is not just working or not (success or failure), but it concerns the “production” of multiple realities when we conduct research in Administration having the processual approach to organizations as a basis