Total Synthesis of the Potent HIF-1 Inhibitory Antitumor Natural Product, (8R)-Mycothiazole, via Baldwin–Lee CsF/CuI sp3–sp2-Stille Cross-Coupling. Confirmation of the Crews Reassignment

A convenient asymmetric total synthesis of the potent HIF-1 inhibitory antitumor natural product, (−)- or (+)-(8R)-mycothiazole (1), is described. Not only does our synthesis confirm the 2006 structural reassignment made by Crews (Crews, P., et al. J. Nat. Prod. 2006, 69, 145), it revises the [α]_D data previously reported for this molecule in MeOH from −13.7° to +42.3°. The newly developed route to (8R)-1 sets the C(8)–OH stereocenter via Sharpless AE/2,3-epoxy alcohol reductive ring opening and utilizes two Baldwin–Lee CsF/cat. CuI Stille cross-coupling reactions with vinylstannanes 8 and 3 to efficiently elaborate the C(1)–C(4) and C(14)–C(18) sectors.

Electron dynamics and frequency coupling in a radio-frequency capacitively biased planar coil inductively coupled plasma system

The electron dynamics in a planar coil inductively coupled plasma (ICP) system with a capacitively biased electrode is investigated using space and phase resolved optical emission spectroscopy. The two power source frequencies are exact multiple of each other and phase-locked. In this configuration, the system is investigated when the coil is operated in both E-mode and H-mode. The results show that in a phase synchronized RF biased ICP, the electrode bias power couples with the capacitive contribution of the coil, in both E-mode and H-modes, similar to dual-frequency capacitively coupled plasmas (2f-CCPs). It is also demonstrated that in H-mode, the phase between the electrode bias frequency and the ICP coil frequency influences the electron heating, similar to the electrical asymmetry effect in 2f-CCPs.

Investigation of tanpura string vibrations using a two-dimensional time-domain model incorporating coupling and bridge friction

Tanpura string vibrations have been investigated previously using numerical models based on energy conserving schemes derived from a Hamiltonian description in one-dimensional form. Such time-domain models have the property that, for the lossless case, the numerical Hamiltonian (representing total energy of the system) can be proven to be constant from one time step
to the next, irrespective of any of the system parameters; in practice the Hamiltonian can be shown to be conserved within machine precision. Models of this kind can reproduce a jvari effect, which results from the bridge-string interaction. However the one-dimensional formulation has recently been shown to fail to replicate the jvaris strong dependence on the thread placement. As a first step towards simulations which accurately emulate this sensitivity to the thread placement, a twodimensional model is proposed, incorporating coupling of controllable level between the two string polarisations at the string termination opposite from the barrier. In addition, a friction force acting when the string slides across the bridge in horizontal direction is introduced, thus effecting a further damping mechanism. In this preliminary study, the string is terminated at the position of the thread. As in the one-dimensional model, an implicit scheme has to be used to solve the system, employing Newton's method to calculate the updated positions and momentums of each string segment. The two-dimensional model is proven to be energy conserving when the loss parameters are set to zero, irrespective of the coupling constant. Both frequency-dependent and independent losses are then added to the string, so that the model can be compared to analogous instruments. The influence of coupling and the bridge friction are investigated.

An eDNA assay for Irish Petromyzon marinus and Salmo trutta and field validation in running water.

This pilot study presents an environmental DNA (eDNA) assay for sea lamprey Petromyzon marinus and brown trout Salmo trutta, two species of economic and conservation importance in the Republic of Ireland. The results demonstrate the effectiveness of eDNA for assessing presence of low-abundance taxa (here, P. marinus) for environmental managers, and they highlight the potential for assessing relative abundance of rare or invasive freshwater species.

Intermediate-coupling R -matrix calculations of electron-impact excitation of Fe 5+

For applications to laboratory and astrophysical plasmas, there is a great need for accurate electron-impact excitation data between individual levels in the lower charge-state ions of iron. Recently, we have reported on the first intermediate-coupling R -matrix calculation of electron-impact excitation in Fe 4+ , in which the close-coupling expansion of the target included levels from both ground and excited configurations (Ballance et al 2007 J. Phys. B: At. Mol. Opt. Phys. [/0953-4075/40/23/f01] 40 F327 , 2008 Europhys. News 39 14). In this paper, we present the results of two large intermediate-coupling Dirac R -matrix calculations of electron-impact excitation of Fe 5+ . The results from the two calculations, which differ only in the configuration–interaction expansions of the target, are compared. These comparisons provide some indication of the accuracy of the calculations and the resulting data should be useful in modelling plasmas containing iron.

Electron-impact excitation of Fe2: a comparison of intermediate coupling frame transformation, Breit-Pauli and Dirac R-matrix calculations

Modeling the spectral emission of low-charge iron group ions enables the diagnostic determination of the local physical conditions of many cool plasma environments such as those found in H II regions, planetary nebulae, active galactic nuclei etc. Electron-impact excitation drives the population of the emitting levels and, hence, their emissivities. By carrying-out Breit-Pauli and intermediate coupling frame transformation (ICFT) R-matrix calculations for the electron-impact excitation of Fe$^{2+}$ which both use the exact same atomic structure and the same close-coupling expansion, we demonstrate the validity of the application of the powerful ICFT method to low-charge iron group ions. This is in contradiction to the finding of Bautista et al. [Ap.J.Lett, 718, L189, (2010)] who carried-out ICFT and Dirac R-matrix calculations for the same ion. We discuss possible reasons.

Electron-impact excitation of Fe 4+ : an intermediate-coupling R -matrix calculation

For a number of years, there has been a major effort to calculate electron-impact excitation data for every ion stage of iron embodied by the ongoing efforts of the IRON project by Hummer et al (1993 Astron. Astrophys. 279 298). Due to the complexity of the targets, calculations for the lower stages of ionization have been limited to either intermediate-coupling calculations within the ground configurations or LS -coupling calculations of the ground and excited configurations. However, accurate excitation data between individual levels within both the ground and excited configurations of the low charge-state ions are urgently required for applications to both astrophysical and laboratory plasmas. Here we report on the results of the first intermediate-coupling R -matrix calculation of electron-impact excitation for Fe 4+ for which the close-coupling (CC) expansion includes not only those levels of the 3d 4 ground configuration, but also the levels of the 3d 3 4s, 3d 3 4p, 3d 3 4d and 3d 2 4s 2 excited configurations. With 359 levels in the CC expansion and over 2400 scattering channels for many of the J Π partial waves, this represents the largest electron–ion scattering calculation to date and it was performed on massively parallel computers using a recently developed set of relativistic parallel R -matrix programs.

The time-dependent close-coupling method for atomic and molecular collision processes

We review the development of the time-dependent close-coupling method to study atomic and molecular few body dynamics. Applications include electron and photon collisions with atoms, molecules, and their ions.

Studies on magnetocaloric and magnetic coupling effects

O presente trabalho apresenta novas metodologias desenvolvidas para a análise das propriedades magnéticas e magnetocalóricas de materiais, sustentadas em considerações teóricas a partir de modelos, nomeadamente a teoria de transições de fase de Landau, o modelo de campo médio molecular e a teoria de fenómeno crítico. São propostos novos métodos de escala, permitindo a interpretação de dados de magnetização de materiais numa perspectiva de campo médio molecular ou teoria de fenómeno crítico. É apresentado um método de estimar a magnetização espontânea de um material ferromagnético a partir de relações entropia/magnetização estabelecidas pelo modelo de campo médio molecular. A termodinâmica das transições de fase magnéticas de primeira ordem é estudada usando a teoria de Landau e de campo médio molecular (modelo de Bean-Rodbell), avaliando os efeitos de fenómenos fora de equilíbrio e de condições de mistura de fase em estimativas do efeito magnetocalórico a partir de medidas magnéticas. Efeitos de desordem, interpretados como uma distribuição na interacção magnética entre iões, estabelecem os efeitos de distribuições químicas/estruturais nas propriedades magnéticas e magnetocalóricas de materiais com transições de fase de segunda e de primeira ordem. O uso das metodologias apresentadas na interpretação das propriedades magnéticas de variados materiais ferromagnéticos permitiu obter: 1) uma análise quantitativa da variação de spin por ião Gadolínio devido à transição estrutural do composto Gd5Si2Ge2, 2) a descrição da configuração de cluster magnético de iões Mn na fase ferromagnética em manganites da família La-Sr e La-Ca, 3) a determinação dos expoentes críticos β e δ do Níquel por métodos de escala, 4) a descrição do efeito da pressão nas propriedades magnéticas e magnetocalóricas do composto LaFe11.5Si1.5 através do modelo de Bean-Rodbell, 5) uma estimativa da desordem em manganites ferromagnéticas com transições de segunda e primeira ordem, 6) uma descrição de campo médio das propriedades magnéticas da liga Fe23Cu77, 7) o estudo de efeitos de separação de fase na família de compostos La0.70-xErxSr0.30MnO3 e 8) a determinação realista da variação de entropia magnética na família de compostos de efeito magnetocalórico colossal Mn1-x-yFexCryAs.

Microphytobenthos vs Hydrobia: trophic coupling in estuarine environment

Os estuários são ambientes complexos, biologicamente diversos e muito importantes no que respeita à produtividade primária. As zonas intertidais destes ecossistemas são ocupadas por organismos que possuem uma elevada capacidade de sobrevivência e adaptação face às variadas e rápidas alterações nos factores ambientais (tais como temperatura, salinidade, conteúdo hídrico, etc.). As cadeias tróficas com origem no ecossistema estuarino bentónico são essencialmente herbívoras, regulando o fluxo de energia desde o fundo sedimentar e através do ecossistema. Nas áreas estuarinas intertidais a produção primária é essencialmente suportada pelo microfitobentos (MPB). Estas comunidades de microalgas bênticas constituem uma importante fonte de matéria orgânica e são por si só a principal fonte alimentar para as populações de Hydrobia. Neste contexto, a interacção MPB - Hydrobia é um modelo-chave na investigação da cadeia trófica estuarina de origem bentónica, actuando como um importante canal de transporte de energia para os níveis tróficos superiores, especialmente se considerarmos que Hydrobia é uma importante presa para peixes, aves e caranguejos. O presente estudo tem por objectivos gerais: i) a investigação do controlo ambiental (particularmente da luz e do teor em água do sedimento) e endógeno na migração vertical do MPB e ii) a identificação e potencial utilização de marcadores tróficos (pigmentos e ácidos gordos) úteis à investigação da interacção MPB – Hydrobia em laboratório e em condições naturais, considerando a existência de uma elevada plasticidade trófica por parte da Hydrobia e a elevada densidade populacional que estes organismos podem apresentar. A primeira fase de investigação resultou na comparação do papel dos estímulos ambientais e do controlo endógeno nos padrões de comportamento migratório vertical do microfitobentos, demonstrando a existência de um controlo essencialmente endógeno na formação e desintegração do biofilme superficial. A regulação e manutenção da biomassa à superfície do sedimento são claramente controladas pela variação dos factores ambientais, em especial da luz, cuja presença é essencial à formação total do biofilme microalgal à superfície do sedimento intertidal. Foi proposta uma nova abordagem metodológica com vista à estimativa nãodestrutiva do teor de água de sedimentos intertidais vasosos , possibilitando o estudo da influência da acção do vento no conteúdo hídrico dos sedimentos e o consequente impacto da dessecação na comunidade microfitobêntica. Observou-se que a dessecação provoca efeitos limitantes não só na biomassa superficial mas também na actividade fotossintética dos biofilmes microfitobênticos, conduzindo à diminuição da produtividade primária. No que respeita à dinâmica trófica da interacção MPB - Hydrobia foi estabelecido o uso do pigmento feoforbide a, quantificado nas partículas fecais da fauna, como marcador trófico que permite estimar a quantidade de biomassa de microalgas (clorofila a) incorporada pelos organismos animais.Para tal foi investigada e comprovada a existência de uma relação significativa entre a concentração de feopigmentos excretados e a concentração de clorofila a ingerida. Estes estudos foram desenvolvidos numa primeira fase à escala diária, considerando os efeitos dos ciclos sazonais, dia-noite e maré, e depois com a validação em condições naturais, numa escala mensal. A taxa de ingestão média de indivíduos de H. ulvae varia ao longo do dia, com o máximo em torno dos períodos diurnos de maré baixa, o que pode estar relacionado com a disponibilidade de MPB. As taxas de ingestão (TI) de H. ulvae variam ainda em função da estação do ano (TI verão > TI primavera) e em função da densidade de indivíduos (> densidade, < ingestão). Verificou-se um efeito negativo na concentração de clorofila disponível após herbívoria independentemente da densidade de indivíduos. Finalmente, a comparação dos perfis de ácidos gordos de H. ulvae provenientes de diferentes habitats com os perfis de potenciais fontes alimentares permitiu demonstrar que os ácidos gordos são ferramentas úteis na identificação do habitat ocupado por estes organismos. No entanto, apesar da ocupação de diferentes habitats e da integração de múltiplas fontes de produção primária na sua dieta foram sempre observados significativos níveis de ácidos gordos específicos de microalgas (em particular diatomáceas), reforçando o papel importante das comunidades de microalgas bênticas na dieta das populações de H. ulvae.

‘Running with the Fox and Hunting with the Hounds’: Social Work Tutors' Experiences of Managing Failing Social Work Students in Practice Learning Settings

The paper explores the issues raised by social work students failing in practice learning settings from the perspective of university tutors, by drawing on existing literature in this area from social work and nursing, as well as findings from a small‐scale empirical qualitative study. The qualitative study was influenced by practitioner‐researcher and practice‐near paradigms; and is based on interviews with twelve social work tutors in England. The findings reveal that tutors are able to articulate the important tasks and functions of their roles when issues of failing students in practice learning settings arise, although the process can be challenging. The challenges include: supporting practice educator and student, concerns about other tutors’ practices, the difficulties in promoting appropriate professional standards and values within higher education contexts and frustrations with practice educators and placements. Only a third of the respondents (four) however, articulated their gate keeping roles and responsibilities although this was not without its difficulties. Given the current reforms in social work education in England at this present time, with greater emphasis on threshold standards at entry level, and at key stages throughout the programme of study, the research is timely in terms of the critical consideration of the tutor role and challenges inherent in promoting appropriate standards.

An Empirical Evaluation of the Reversal Theory State Measure: Tracking Changes in the Experience of Video Commercials of Three Leading Running Brands

Abstract of paper delivered at the 17th International Reversal Theory Conference, Day 3, session 4, 01.07.15

An Empirical Evaluation of the Reversal Theory State Measure Using Three Running Brand Video Commercials

This paper reports on the first known empirical use of the Reversal Theory State Measure (RTSM) since its publication by Desselles et al. (2014). The RTSM was employed to track responses to three purposely-selected video commercials in a between-subjects design. Results of the study provide empirical support for the central conceptual premise of reversal theory, the experience of metamotivational reversals and the ability of the RTSM to capture them. The RTSM was also found to be psychometrically sound after adjustments were made to two of its three component subscales. Detailed account and rationale is provided for the analytical process of assessing the psychometric robustness of the RTSM, with a number of techniques and interpretations relating to component structure and reliability discussed. Agreeability and critique of the two available versions of the RTSM – the bundled and the branched – is also examined. Researchers are encouraged to assist development of the RTSM through further use, taking into account the analysis and recommendations presented.

Coupling anchovy eggs and hydrodynamic model as an assessement tool for estuarine ecohydrological management

Nitrate and urban waste water directives have raised the need for a better understanding of coastal systems in European Union. The incorrect application of these directives can lead to important ecological or social penalties. In the paper this problem is addressed to Ria Formosa Coastal Lagoon. Ria Formosa hosts a Natural Park, important ports of the southern Portuguese coast and significant bivalve aquaculture activity. Four major urban waste water treatment plants discharging in the lagoon are considered in this study. Its treatment level must be selected, based on detailed information from a monitoring program and on a good knowledge of the processes determining the fate of the material discharged in the lagoon. In this paper the results of a monitoring program and simulations using a coupled hydrodynamic and water quality / ecological model, MOHID, are used to characterise the system and to understand the processes in Ria Formosa. It is shown that the water residence time in most of the lagoon is quite low, of the order of days, but it can be larger in the upper parts of the channels where land generated water is discharged. The main supply of nutrients to the lagoon comes from the open sea rather than from the urban discharges. For this reason the characteristics and behaviour of the general lagoon contrasts with the behaviour of the upper reaches of the channels where the influence of the waste water treatment plants are high. In this system the bottom mineralization was found to be an important mechanism, and the inclusion of that process in the model was essential to obtain good results.