Synthesis of some new pyrimidine and pyridopyrimidine derivatives

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Temas y problemas en Antropología Social

El presente texto tiene que ver con el programa de la materia Antropología Cultural y Social dictada en la Facultad de Psicología de nuestra Universidad de La Plata. Sus diversos capítulos cubren varios temas del curso y fueron antecedidos por otros textos temáticos menos formalizados, editados anteriormente por la Cátedra. Nos ha parecido siempre importante adaptar los conocimientos de la Antropología en el marco de las Ciencias Sociales y de la Antropología Social en particular -que constituyen el eje de la materia- con la intención de conformar un eje didáctico de materiales que sean de fácil comprensión y permitan una lectura ulterior de mayor profundidad y continuidad, según el avance en la construcción de los conocimientos por parte de alumnos. Esto es importante por cuanto la disciplina constituye, de acuerdo al nuevo perfil del Plan de Estudios, uno de los cuatro pilares de conocimiento básico de la Psicología. En este sentido, se la considera un ámbito disciplinar académico destacado que aporta a los estudiantes herramientas conceptual-metodológicas básicas para la lectura y comprensión crítica del contexto sociohistórico, cultural y político en el que desarrollan sus prácticas actuales y su futura práctica profesional. Con una perspectiva más amplia se ha pensado, al redactar los capítulos, en el posible interés que puedan tener su lectura en el ámbito general de la Universidad.Facultad de Psicologí

Taking a walk: the female tourist experience

This feminist, qualitative study explores the experiences of female tourists who like to walk during their holiday. The findings highlight that women’s full access to the benefits of walking whilst on holiday are constrained by their feelings of vulnerability and their perceptions of possible risk if walking alone, particularly at night and in isolated spaces. In order to cope with perceived risk, participants employed a number of safeguarding and self-surveillance strategies. This study therefore supports other research on female tourists that highlight the differences among male and female tourist experiences, and that point to the measures women take to keep themselves safe

Elemental and configural olfactory coding by antennal lobe neurons of the honeybee (Apis mellifera)

When smelling an odorant mixture, olfactory systems can be analytical (i.e. extract information about the mixture elements) or synthetic (i.e. creating a configural percept of the mixture). Here, we studied elemental and configural mixture coding in olfactory neurons of the honeybee antennal lobe, local neurons in particular. We conducted intracellular recordings and stimulated with monomolecular odorants and their coherent or incoherent binary mixtures to reproduce a temporally dynamic environment. We found that about half of the neurons responded as ‘elemental neurons’, i.e. responses evoked by mixtures reflected the underlying feature information from one of the components. The other half responded as ‘configural neurons’, i.e. responses to mixtures were clearly different from responses to their single components. Elemental neurons divided in late responders (above 60 ms) and early responder neurons (below 60 ms), whereas responses of configural coding neurons concentrated in-between these divisions. Latencies of neurons with configural responses express a tendency to be faster for coherent stimuli which implies employment in different processing circuits

Encoding Odorant Identity by Spiking Packets of Rate-Invariant Neurons in Awake Mice

Background: How do neural networks encode sensory information? Following sensory stimulation, neural coding is commonly assumed to be based on neurons changing their firing rate. In contrast, both theoretical works and experiments in several sensory systems showed that neurons could encode information as coordinated cell assemblies by adjusting their spike timing and without changing their firing rate. Nevertheless, in the olfactory system, there is little experimental evidence supporting such model. Methodology/Principal Findings: To study these issues, we implanted tetrodes in the olfactory bulb of awake mice to record the odorant-evoked activity of mitral/tufted (M/T) cells. We showed that following odorant presentation, most M/T neurons do not significantly change their firing rate over a breathing cycle but rather respond to odorant stimulation by redistributing their firing activity within respiratory cycles. In addition, we showed that sensory information can be encoded by cell assemblies composed of such neurons, thus supporting the idea that coordinated populations of globally rateinvariant neurons could be efficiently used to convey information about the odorant identity. We showed that different coding schemes can convey high amount of odorant information for specific read-out time window. Finally we showed that the optimal readout time window corresponds to the duration of gamma oscillations cycles. Conclusion: We propose that odorant can be encoded by population of cells that exhibit fine temporal tuning of spiking activity while displaying weak or no firing rate change. These cell assemblies may transfer sensory information in spikin

Oxidative protein labeling in mass-spectrometry-based proteomics

Oxidation of proteins and peptides is a common phenomenon, and can be employed as a labeling technique for mass-spectrometry-based proteomics. Nonspecific oxidative labeling methods can modify almost any amino acid residue in a protein or only surface-exposed regions. Specific agents may label reactive functional groups in amino acids, primarily cysteine, methionine, tyrosine, and tryptophan. Nonspecific radical intermediates (reactive oxygen, nitrogen, or halogen species) can be produced by chemical, photochemical, electrochemical, or enzymatic methods. More targeted oxidation can be achieved by chemical reagents but also by direct electrochemical oxidation, which opens the way to instrumental labeling methods. Oxidative labeling of amino acids in the context of liquid chromatography(LC)–mass spectrometry (MS) based proteomics allows for differential LC separation, improved MS ionization, and label-specific fragmentation and detection. Oxidation of proteins can create new reactive groups which are useful for secondary, more conventional derivatization reactions with, e.g., fluorescent labels. This review summarizes reactions of oxidizing agents with peptides and proteins, the corresponding methodologies and instrumentation, and the major, innovative applications of oxidative protein labeling described in selected literature from the last decade

ACTRIS non-methane hydrocarbon intercomparison experiment in Europe to support WMO GAW and EMEP observation networks

The performance of 18 European institutions involved in long-term non-methane hydrocarbon (NMHC) measurements in ambient air within the framework of the Global Atmosphere Watch (GAW) and the European Monitoring and Evaluation Programme (EMEP) was assessed with respect to data quality objectives (DQOs) of ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) and GAW. Compared to previous intercomparison studies the DQOs define a novel approach to assess and ensure a high quality of the measurements. Having already been adopted by GAW, the ACTRIS DQOs are demanding with deviations to a reference value of less than 5% and a repeatability of better than 2% for NMHC mole fractions above 0.1 nmol mol(-1). The participants of the intercomparison analysed two dry gas mixtures in pressurised cylinders, a 30-component NMHC mixture in nitrogen (NMHC_N-2 /at approximately 1 nmol mol(-1) and a whole air sample (NMHC_air), following a standardised operation procedure including zero-and calibration gas measurements. Furthermore, participants had to report details on their instruments and assess their measurement uncertainties. The NMHCs were analysed either by gas chromatography-flame ionisation detection (GC-FID) or by gas chromatography-mass spectrometry (GC-MS). For the NMHC_N-2 measurements, 62% of the reported values were within the 5% deviation class corresponding to the ACTRIS DQOs. For NMHC_air, generally more frequent and larger deviations to the assigned values were observed, with 50% of the reported values within the 5% deviation class. Important contributors to the poorer performance in NMHC_air compared to NMHC_N-2 were a more complex matrix and a larger span of NMHC mole fractions (0.03-2.5 nmol mol(-1)). The performance of the participating laboratories were affected by the different measurement procedures such as the usage of a two-step vs. a one-step calibration, breakthroughs of C-2-C-3 hydrocarbons in the focussing trap, blank values in zero-gas measurements (especially for those systems using a Nafion (R) Dryer), adsorptive losses of aromatic compounds, and insufficient chromatographic separation.Peer reviewe