Nucleic acid structure and sequence probing using fluorescent base analogue tC^o

The fluorescent cytosine analog tC(o) is on average the brightest probe of its kind and, moreover, it introduces minimal perturbations to the normal secondary structure of DNA. Here several ways of how tC(o), with an advantage, can be used as a local fluorescent probe in nucleic acid systems are presented. Most importantly, we show that tCo is an excellent probe for the detection of individual melting processes of complex nucleic acid structures containing a large number of separate secondary structure motifs. Since conventional UV-melting investigations merely monitor the global melting process of the whole nucleic acid structure, e.g. multi-hairpin systems in RNA/DNA, and thus is incapable of estimating individual melting transitions of such systems, tC(o) represents a new method of characterization. Furthermore, we find that tCo may be used to detect bulges and loops in nucleic acids as well as to distinguish a matched base-pair from several of the mismatched

Highly efficient incorporation of the fluorescent nucleotide analogs tC and tCO by Klenow fragment

Studies of the mechanisms by which DNA polymerases select the correct nucleotide frequently employ fluorescently labeled DNA to monitor conformational rearrangements of the polymerase–DNA complex in response to incoming nucleotides. For this purpose, fluorescent base analogs play an increasingly important role because they interfere less with the DNA–protein interaction than do tethered fluorophores. Here we report the incorporation of the 5′-triphosphates of two exceptionally bright cytosine analogs, 1,3-diaza-2-oxo-phenothiazine (tC) and its oxo-homolog, 1,3-diaza-2-oxo-phenoxazine (tCO), into DNA by the Klenow fragment. Both nucleotide analogs are polymerized with slightly higher efficiency opposite guanine than cytosine triphosphate and are shown to bind with nanomolar affinity to the DNA polymerase active site, according to fluorescence anisotropy measurements. Using this method, we perform competitive binding experiments and show that they can be used to determine the dissociation constant of any given natural or unnatural nucleotide. The results demonstrate that the active site of the Klenow fragment is flexible enough to tolerate base pairs that are size-expanded in the major groove. In addition, the possibility to enzymatically polymerize a fluorescent nucleotide with high efficiency complements the tool box of biophysical probes available to study DNA replication

Structural and magnetic properties of isovalently substituted multiferroic BiFeO3: Insights from Raman spectroscopy

Raman spectra, supplemented by powder x-ray diffraction and magnetization data of isovalently A- and B-site substituted BiFeO3 in the Bi1−xLaxFeO3 (0≤x≤1), Bi1−xTbxFeO3 (0≤x≤0.2), and Bi0.9Sm0.1Fe1−xMnxO3 (0≤x≤0.3) series, are presented. A good agreement between the structural transitions observed by x-ray diffraction and the vibrational modes observed in the Raman spectra is found over the whole substitutional ranges, and in particular we find spectroscopic signatures of a PbZrO3-type structure for Bi0.8La0.2FeO3. Mode assignments in the substituted materials are made based on Raman spectra of the end-members BiFeO3 and LaFeO3. Moreover, by comparing spectra from all samples with R3c structure, the phonon assignment in BiFeO3 is revisited. A close connection between the degree of octahedral tilt and the Raman shift of the A1 oxygen a−a−a− tilt mode is established. An explanation for the strong second-order scattering observed in Bi1−xLaxFeO3 and Bi1−xTbxFeO3 is suggested, including the assignment of the previously mysterious BiFeO3 mode at 620 cm−1. Finally, the magnetization data indicates a transition from a cycloidal modulated state towards a canted antiferromagnet with increasing A-site substitution, while Bi0.9Sm0.1Fe1−xMnxO3 with x=0 and 0.15 exhibit an anomalous closing of the hysteresis loop at low temperatures. For low A-site substitution levels (x≤0.1) the decreasing Raman intensity of the Fe derived modes correlates with the partial destruction of the spin cycloid as the substitution level increases

Transport appraisal revisited

Cost-benefit analysis has become a widely used and well developed tool for evaluation of suggested transport projects. This paper presents our view of the role and position of CBA in a transport planning process, partly based on a survey of a number of countries where CBA plays a formalised role in decision making. The survey shows that methodologies, valuations and areas of application are broadly similar across countries. All countries place the CBA results in a comprehensive assessment framework that also includes various types of non-monetised benefits. An important advantage with using CBA is that it is a way to overcome cognitive, structural and process-related limitations and biases in decision making. Some of the main challenges to CBA and to quantitative assessment in general lie in the institutional and political context. There is often a risk that CBA enters the planning process too late to play any meaningful role. This risk seems to increase when planning processes are centred around a perceived "problem". If the problem is perceived as important enough, even inefficient solutions may be viewed as better than nothing, despite that the definition of what constitutes a "problem" is often arbitrary

Cultura y el clima organizacional en una empresa de servicio público de electricidad

El enfoque de una organización como cultura es una manifestación relativamente novedosa, la percepción hasta hace unos pocos años era bastante distinta, a una organización se le veía sólo como un ente funcional que sólo servía para dirigir, supervisar y controlar a un grupo humano, pero en la actualidad la visión es bastante diferente. Tal como las personas que la integran una organización también tiene personalidad y de acuerdo a dichas personas, esta puede ser rígida o flexible, innovadora o conservadora, tradicional o vanguardista, etc. Dicho concepto ha comenzado a aceptarse recientemente, reconociéndose el rol que desempeñan la cultura y el clima organizacional como factores que vinculan las actitudes y el comportamiento. La cultura y el clima organizacional tienen importancia estratégica y representan una fortaleza propia dentro de cada organización, pudiéndola conducir hacia el éxito y hacia la optimización de sus objetivos. Dicha importancia ha venido siendo tema de insoslayable interés desde hace dos décadas, estando el presente trabajo de investigación orientado a destacar y fundamentar estos aspectos como vías que conducirán a una determinada empresa u organización hacia el éxito, y en la forma en que los elementos de ésta disciplina van a afectar la eficacia y eficiencia del trabajo de las empresas públicas o privadas y la consecución de los objetivos de cualquier institución, como en el caso específico de ELECTROCENTRO HUANCAYO. En dicha empresa se llevará a cabo el estudio conciliando un cuestionario que tendrá como objetivo el de medir la cultura y el clima organizacional, para cotejarlo con un índice de eficiencia que se obtendrá de las evaluaciones periódicas del personal de dicha institución. Los valores obtenidos en ambos procesos serán la materia prima, la cual una vez procesada y analizada bajo las técnicas estadísticas correspondientes, arrojarán los resultados que reflejen la realidad del clima y la cultura organizacional en ELECTROCENTRO HUANCAYO.Fil: Galarza Rosazza, Luis. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

New appraisal values of travel time saving and reliability in Great Britain

© 2017, The Author(s). This paper provides an overview of the study ‘Provision of market research for value of time savings and reliability’ undertaken by the Arup/ITS Leeds/Accent consortium for the UK Department for Transport (DfT). The paper summarises recommendations for revised national average values of in-vehicle travel time savings, reliability and time-related quality (e.g. crowding and congestion), which were developed using willingness-to-pay (WTP) methods, for a range of modes, and covering both business and non-work travel purposes. The paper examines variation in these values by characteristics of the traveller and trip, and offers insights into the uncertainties around the values, especially through the calculation of confidence intervals. With regards to non-work, our recommendations entail an increase of around 50% in values for commute, but a reduction of around 25% for other non-work—relative to previous DfT ‘WebTAG’ guidance. With regards to business, our recommendations are based on WTP, and thus represent a methodological shift away from the cost saving approach (CSA) traditionally used in WebTAG. These WTP-based business values show marked variation by distance; for trips of less than 20miles, values are around 75% lower than previous WebTAG values; for trips of around 100miles, WTP-based values are comparable to previous WebTAG; and for longer trips still, WTP-based values exceed those previously in WebTAG

Agree to Agree: Agreement in the Minimalist Programme

Agreement is a pervasive phenomenon across natural languages. Depending on one’s definition of what constitutes agreement, it is either found in virtually every natural language that we know of, or it is at least found in a great many. Either way, it seems to be a core part of the system that underpins our syntactic  knowledge. Since the introduction of the operation of Agree in Chomsky (2000), agreement phenomena and the mechanism that underlies agreement have garnered a lot of attention in the Minimalist literature and have received different theoretical treatments at different stages. Since then, many different phenomena  involving dependencies between elements in syntax, including movement or not, have been accounted for using Agree. The mechanism of Agree thus provides a powerful tool to model dependencies between syntactic elements far beyond φ-feature agreement. The articles collected in this volume further explore these topics  and contribute to the ongoing debates surrounding agreement. The authors gathered in this book are internationally reknown experts in the field of Agreement

Agree to Agree: Agreement in the Minimalist Programme

Agreement is a pervasive phenomenon across natural languages. Depending on one’s definition of what constitutes agreement, it is either found in virtually every natural language that we know of, or it is at least found in a great many. Either way, it seems to be a core part of the system that underpins our syntactic  knowledge. Since the introduction of the operation of Agree in Chomsky (2000), agreement phenomena and the mechanism that underlies agreement have garnered a lot of attention in the Minimalist literature and have received different theoretical treatments at different stages. Since then, many different phenomena  involving dependencies between elements in syntax, including movement or not, have been accounted for using Agree. The mechanism of Agree thus provides a powerful tool to model dependencies between syntactic elements far beyond φ-feature agreement. The articles collected in this volume further explore these topics  and contribute to the ongoing debates surrounding agreement. The authors gathered in this book are internationally reknown experts in the field of Agreement