1,870 research outputs found

    Experimental Verification of a Depth Controller using Model Predictive Control with Constraints onboard a Thruster Actuated AUV

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    In this work a depth and pitch controller for an autonomous underwater vehicle (AUV) is developed. This controller uses the model predictive control method to manoeuvre the vehicle whilst operating within the defined constraints of the AUV actuators. Experimental results are given for the AUV performing a step change in depth whilst maintaining zero pitch

    Tautomeric Equilibria Studies by Mass Spectrometry

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    Tautomerism in organic chemistry has been extensively studied in condensed phase by spectrometric methods, mainly by IR and NMR techniques. Mass spectrometry studies start 40 years ago but just recently it has been recognized the importance of the mass spectral data for the study of tautomerism in the gas phase.
Mass spectrometry can provide valuable information in regard to tautomeric equilibria when studying mass spectra among the members of different families of organic compounds.
The relevance of the mass spectral data resides on several facts but there are two that are of key importance:
1-	Mass spectral fragmentation assignments should be tautomer specific since the corresponding abundances ratios are supposed to be correlated to the keto/enol contents.
2-	Ionization in the ion source is supposed to have no effect on the position of the equilibrium so that the results reflect the tautomers content in the gas phase previous to ionization.
Some of the carbonylic compounds do not exhibit noticeable tautomerism so the fragment abundances assigned to the enol form is very low or not measurable. Since enolization is more noticeable in the case of thio-derivatives (which correlates adequately with the oxygenated analogues), the study of their mass spectra is an interesting choice to reach some degree of generalization. 
In addition, experimental findings are supported by semiempirical theoretical calculations, which probed to be adequate not only for supporting tendency correlations among the members of a compound family but also to calculate heats of tautomerization in gas phase.
Reports using mass spectrometry for tautomerism are becoming less common. One of the reasons is that now it would appear that the interpretation of MS results is not as straightforward as it was once believed, even though in a recent review it was written that: “Mass spectrometry is the most informative and practical method for studying and identifying tautomers in the gas phase” [1]. 
In fact, mass spectrometry seems to be very informative for studying and identifying tautomers, because in this case external factors like solvents, intermolecular interactions, etc., can be excluded by transferring the tautomeric system into gas phase, where the process becomes truly unimolecular [1].
This review covers the study of Tautomerism by Mass Spectrometry in the last four decades. 
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    Evaluating the specialist palliative care clinical nurse specialist role in an acute hospital setting: a mixed methods sequential explanatory study.

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    Special palliative care is provided in a range of settings including a patient's home (their primary place of dwelling), a hospice in-patient unit, or an acute hospital. The aim of the study was to evaluate the role of the specialist in palliative care clinical nurse specialist (SPC CNS) role in an acute hospital setting. This study was conducted using a mixed methods sequential explanatory approach in two phases; phase 1 involved completion of a study questionnaire (n = 121) and phase 2 involved part-taking in a focus group (n = 6) or individual interview (n = 4). Phase 1 results indicated that respondents held positive attitudes towards the Specialist Palliative Care Clinical Nurses Specialist (SPC CNS) in relation to clinical care, education and patient advocacy. Phase 2 qualitative findings identified the importance of the role in terms of symptom management, education and support. This study provides an evaluation of a SPC CNS role since it was established in an acute hospital setting. The evidence indicates that there is a varied understanding of the role of the SPC CNS. The role was seen as an important one particularly in terms of referrals to and support provided by the SPC CNS, as well as recognition of the importance of the role is providing ongoing education to staff

    The degree of enhancer or promoter activity is reflected by the levels and directionality of eRNA transcription

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    Gene expression is regulated by promoters, which initiate transcription, and enhancers, which control their temporal and spatial activity. However, the discovery that mammalian enhancers also initiate transcription questions the inherent differences between enhancers and promoters. Here, we investigate the transcriptional properties of enhancers during Drosophila embryogenesis using characterized developmental enhancers. We show that while the timing of enhancer transcription is generally correlated with enhancer activity, the levels and directionality of transcription are highly varied among active enhancers. To assess how this impacts function, we developed a dual transgenic assay to simultaneously measure enhancer and promoter activities from a single element in the same embryo. Extensive transgenic analysis revealed a relationship between the direction of endogenous transcription and the ability to function as an enhancer or promoter in vivo, although enhancer RNA (eRNA) production and activity are not always strictly coupled. Some enhancers (mainly bidirectional) can act as weak promoters, producing overlapping spatio–temporal expression. Conversely, bidirectional promoters often act as strong enhancers, while unidirectional promoters generally cannot. The balance between enhancer and promoter activity is generally reflected in the levels and directionality of eRNA transcription and is likely an inherent sequence property of the elements themselves.Fil: Mikhaylichenko, Olga. European Molecular Biology Laboratory; AlemaniaFil: Bondarenko, Vladyslav. European Molecular Biology Laboratory; AlemaniaFil: Harnett, Dermot. European Molecular Biology Laboratory; AlemaniaFil: Schor, Ignacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Males, Matilda. European Molecular Biology Laboratory; AlemaniaFil: Viales, Rebecca R.. European Molecular Biology Laboratory; AlemaniaFil: Furlong, Eileen E. M.. European Molecular Biology Laboratory; Alemani

    Changing times in England: the influence on geography teachers’ professional practice

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    School geography in England has been characterised as a pendulum swinging between policies that emphasise curriculum and pedagogy alternately. In this paper, I illustrate the influence of these shifts on geography teacher's professional practice, by drawing on three “moments” from my experience as a student, teacher and teacher educator. Barnett's description of teacher professionalism as a continuous project of “being” illuminates how geography teachers can adapt to competing influences. It reflects teacher professionalism as an unfinished project, which is responsive, but not beholden, to shifting trends, and is informed by how teachers frame and enact policies. I argue that recognising these contextual factors is key to supporting geography teachers in “being” geography education professionals. As education becomes increasingly competitive on a global scale, individual governments are looking internationally for “solutions” to improve educational rankings. In this climate, the future of geography education will rest on how teachers react locally to international trends. Geography teacher educators can support this process by continuing to inform the field through meaningful geography education research, in particular in making the contextual factors of their research explicit. This can be supported through continued successful international collaboration in geography education research

    The auditory evoked-gamma response and its relation with the N1m

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    This study explored the patterns of oscillatory activity that underpin the N1m auditory evoked response. Evoked gamma activity is a small and relatively rarely-reported component of the auditory evoked response, and the objective of this work was to determine how this component relates to the larger and more prolonged changes in lower frequency bands. An event-related beamformer analysis of MEG data from monaural click stimulation was used to reconstruct volumetric images and virtual electrode time series. Group analysis of localisations showed that activity in the gamma band originated from a source that was more medial than those for activity in the theta-to-beta band, and virtual-electrode analysis showed that the source of the gamma activity could be statistically dissociated from the lower-frequency response. These findings are in accordance with separate functional roles for the activity in each frequency band, and provide evidence that the oscillatory activity that underpins the auditory evoked response may contain important information about the physiological basis of the macroscopic signals recorded by MEG in response to auditory stimulation

    Non-coding RNA Expression, Function, and Variation during Drosophila Embryogenesis

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    Long non-coding RNAs (lncRNAs) can often function in the regulation of gene expression during development; however, their generality as essential regulators in developmental processes and organismal phenotypes remains unclear. Here, we performed a tailored investigation of lncRNA expression and function during Drosophila embryogenesis, interrogating multiple stages, tissue specificity, nuclear localization, and genetic backgrounds. Our results almost double the number of annotated lncRNAs expressed at these embryonic stages. lncRNA levels are generally positively correlated with those of their neighboring genes, with little evidence of transcriptional interference. Using fluorescent in situ hybridization, we report the spatiotemporal expression of 15 new lncRNAs, revealing very dynamic tissue-specific patterns. Despite this, deletion of selected lncRNA genes had no obvious developmental defects or effects on viability under standard and stressed conditions. However, two lncRNA deletions resulted in modest expression changes of a small number of genes, suggesting that they fine-tune expression of non-essential genes. Several lncRNAs have strain-specific expression, indicating that they are not fixed within the population. This intra-species variation across genetic backgrounds may thereby be a useful tool to distinguish rapidly evolving lncRNAs with as yet non-essential roles.Fil: Schor, Ignacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. European Molecular Biology Laboratory; AlemaniaFil: Bussotti, Giovanni. European Bioinformatics Institute; Reino UnidoFil: Maleš, Matilda. European Molecular Biology Laboratory; AlemaniaFil: Forneris, Mattia. European Molecular Biology Laboratory; AlemaniaFil: Viales, Rebecca R.. European Molecular Biology Laboratory; AlemaniaFil: Enright, Anton J.. European Bioinformatics Institute; Reino UnidoFil: Furlong, Eileen E. M.. European Molecular Biology Laboratory; Alemani
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