Synthesis and characterisation of novel ferrocenyl thienyl and thiazolyl systems

Ferrocenyl derivatives are currently under investigation by our group and several series containing both amidothienyl and amidothiazolyl systems have been synthesised and characterised. The incorporation of thienyl/thiazolyl groups into a ferrocenyl- or ferrocenylphenyl system greatly enhances the number of potential donor atoms for coordination with metal fragments e.g. PtII, PdII with a view to platinum anti-cancer studies and/or interaction with guest molecules through suitable hydrogen bonding interactions. In nature, thiazole has been found to be vital in certain natural products: examples include the antibiotic bacitracin and the siderophore yersiniabactin. In therapeutic studies the antitumour compound epothilone A and myxothiazole (inhibitor) have been extensively studied

Methyl 2-(4-ferrocenylbenzamido)thiophene-3-carboxylate and ethyl 2-(4-ferrocenylbenzamido)-1,3-thiazole-4-acetate, a unique ferrocen

The conformations and hydrogen bonding in the thiophene and thiazole title compounds, [Fe(C₅H₅)(C₂₀H₁₄NO₃S)], (I), and [Fe(C₅H₅)(C₁₉H₁₇N₂O₃S)], (II), are discussed. The sequence (C₅H₄)-(C₆H₄)-(CONH)-(C₄H₂S)-(CO₂Me) of rings and moieties in (I) is close to being planar; all consecutive interplanar angles are less than 10°. An intramolecular N-H...O=Cester hydrogen bond [graph set S(6), N...O = 2.768 (2) Å and N-H...O = 134 (2)°] effects the molecular planarity, and aggregation occurs via hydrogen-bonded chains formed from intermolecular Car-H...O=Cester/amide interactions along [010], with C...O distances ranging from 3.401 (3) to 3.577 (2) Å. The thiazole system in (II) crystallizes with two molecules in the asymmetric unit; these differ in the conformation along their long molecular axes; for example, the interplanar angle between the phenylene (C₆H₄) and thiazole (C₃NS) rings is 8.1 (2)° in one molecule and 27.66 (14)° in the other. Intermolecular N-H...O=Cester hydrogen bonds [N...O = 2.972 (4) and 2.971 (3) Å], each augmented by a Cphenylene-H...O=Cester interaction [3.184 (5) and 3.395 (4) Å], form motifs with graph set R¹₂(7) and generate chains along [100]. The amide C=O groups do not participate in hydrogen bonding. Compound (II) is the first reported ferrocenyl-containing thiazole structure

Optimal tensioning of nonlinear antenna structures

A new technique is described for optimizing the shape of a hoop/column antenna by adjusting the tensioning loads. The antenna structure is modelled using finite element procedures which include the geometric nonlinearities. The finite element equations constitute nonlinear equality constraints in the optimization problem. The new optimization technique solves this optimization problem without the introduction of either Lagrange multipliers or penalty functions. The results for two sample problems are presented in this dissertation

Development of a finite element based delamination analysis for laminates subject to extension, bending, and torsion

Delamination is a common failure mode of laminated composite materials. This type of failure frequently occurs at the free edges of laminates where singular interlaminar stresses are developed due to the difference in Poisson's ratios between adjacent plies. Typically the delaminations develop between 90 degree plies and adjacent angle plies. Edge delamination has been studied by several investigators using a variety of techniques. Recently, Chan and Ochoa applied the quasi-three-dimensional finite element model to the analysis of a laminate subject to bending, extension, and torsion. This problem is of particular significance relative to the structural integrity of composite helicopter rotors. The task undertaken was to incorporate Chan and Ochoa's formulation into a Raju Q3DG program. The resulting program is capable of modeling extension, bending, and torsional mechanical loadings as well as thermal and hygroscopic loadings. The addition of the torsional and bending loading capability will provide the capability to perform a delamination analysis of a general unsymmetric laminate containing four cracks, each of a different length. The solutions obtained using this program are evaluated by comparing them with solutions from a full three-dimensional finite element solution. This comparison facilitates the assessment of three dimensional affects such as the warping constraint imposed by the load frame grips. It wlso facilitates the evaluation of the external load representation employed in the Q3D formulation. Finally, strain energy release rates computed from the three-dimensional results are compared with those predicted using the quasi-three-dimensional formulation

Edge delamination of composite laminates subject to combined tension and torsional loading

Delamination is a common failure mode of laminated composite materials. Edge delamination is important since it results in reduced stiffness and strength of the laminate. The tension/torsion load condition is of particular significance to the structural integrity of composite helicopter rotor systems. Material coupons can easily be tested under this type of loading in servo-hydraulic tension/torsion test stands using techniques very similar to those used for the Edge Delamination Tensile Test (EDT) delamination specimen. Edge delamination of specimens loaded in tension was successfully analyzed by several investigators using both classical laminate theory and quasi-three dimensional (Q3D) finite element techniques. The former analysis technique can be used to predict the total strain energy release rate, while the latter technique enables the calculation of the mixed-mode strain energy release rates. The Q3D analysis is very efficient since it produces a three-dimensional solution to a two-dimensional domain. A computer program was developed which generates PATRAN commands to generate the finite element model. PATRAN is a pre- and post-processor which is commonly used with a variety of finite element programs such as MCS/NASTRAN. The program creates a sufficiently dense mesh at the delamination crack tips to support a mixed-mode fracture mechanics analysis. The program creates a coarse mesh in those regions where the gradients in the stress field are low (away from the delamination regions). A transition mesh is defined between these regions. This program is capable of generating a mesh for an arbitrarily oriented matrix crack. This program significantly reduces the modeling time required to generate these finite element meshes, thus providing a realistic tool with which to investigate the tension torsion problem

Effects of antenatal betamethasone on preterm human and mouse ductus arteriosus: comparison with baboon data.

BackgroundAlthough studies involving preterm infants ≤34 weeks gestation report a decreased incidence of patent ductus arteriosus after antenatal betamethasone, studies involving younger gestation infants report conflicting results.MethodsWe used preterm baboons, mice, and humans (≤276/7 weeks gestation) to examine betamethasone's effects on ductus gene expression and constriction both in vitro and in vivo.ResultsIn mice, betamethasone increased the sensitivity of the premature ductus to the contractile effects of oxygen without altering the effects of other contractile or vasodilatory stimuli. Betamethasone's effects on oxygen sensitivity could be eliminated by inhibiting endogenous prostaglandin/nitric oxide signaling. In mice and baboons, betamethasone increased the expression of several developmentally regulated genes that mediate oxygen-induced constriction (K+ channels) and inhibit vasodilator signaling (phosphodiesterases). In human infants, betamethasone increased the rate of ductus constriction at all gestational ages. However, in infants born ≤256/7 weeks gestation, betamethasone's contractile effects were only apparent when prostaglandin signaling was inhibited, whereas at 26-27 weeks gestation, betamethasone's contractile effects were apparent even in the absence of prostaglandin inhibitors.ConclusionsWe speculate that betamethasone's contractile effects may be mediated through genes that are developmentally regulated. This could explain why betamethasone's effects vary according to the infant's developmental age at birth

La collecte comme iconoclasme

Durant la première moitié du xixe siècle, de nombreux objets importants de Polynésie furent collectés par la London Missionary Society et exposés dans son musée de Londres. Plusieurs sont abordés dans cet article. L’acquisition de ces objets, souvent référencés comme des idoles, était un processus plus complexe qu’on l’a souvent imaginé, qui impliquait des choix stratégiques pour les Polynésiens comme pour les missionnaires. On suggère que la préservation de ces objets a été faite sous l’émulation du chef tahitien Pomaré en 1816, et que différents types de pratiques iconoclastes eurent lieu, depuis l’iconoclasme par destruction jusqu’à l’iconoclasme par neutralisation et préservation. Polynésiens et missionnaires avaient des raisons évidentes de préférer l’iconoclasme par préservation, les premiers dans le but d’obtenir des trophées de leurs victoires sur leurs rivaux et de fournir des preuves matérielles de leur conversion, les seconds afin de fournir des preuves matérielles des succès de leur évangélisation et d’obtenir des fonds à travers les expositions au musée de la London Missionary Society. Ces opérations permirent la survie d’objets aujourd’hui réévalués comme une part importante du patrimoine et comme des œuvres d’art majeures.In the first half of the 19th century many important religious objects from Polynesia were collected by the London Missionary Society and displayed in their museum in London. Several are discussed in this paper. The acquisition of these objects, often referred to as idols, was a more complex process than often imagined, and one which involved strategic choices by Polynesians as well as missionaries. It is proposed that the preservation of these objects was stimulated by the Tahitian chief Pomare in 1816, and that different kinds of iconoclastic practice were enacted, from iconoclasm by annihilation to iconoclasm by disempowerment and preservation. Polynesians and missionaries alike had clear motives to enact iconoclasm by preservation, the former to obtain trophies from rivals and supply material tokens of conversion, the latter to provide evidence of evangelical success and a means of raising funds through exhibition in the London Missionary Society museum. These actions resulted in the survival of objects that are now being re-evaluated as important items of heritage and great works of art

Representation of Theory in Occupational Therapy Education: An International Systematic Mapping Review, 1940-2015

Previous review research has outlined the state of various aspects of occupational therapy education. No reviews, however, have examined how theory, specifically, is represented in educational scholarship. This systematic mapping review explored the way in which theory, as it relates to both occupational therapy practice and pedagogy, has been discussed throughout occupational therapy education scholarship. In the education scholarship, theory pertaining to occupational therapy practice often overlaps with theory pertaining to pedagogy; therefore, both domains were included in the review. A systematic search for occupational therapy education literature published between 1940 and 2015 resulted in 9765 unique citations, 556 of which met inclusion criteria. Papers were coded for curriculum design, teaching methods, research design, and theoretical content. This paper presents findings related to theoretical content. Results demonstrated that theory, when referenced, referred to established social science theories more prominently than occupational therapy specific theory, until recent decades. Further, theory was often treated as a footnote to the main discussion rather than as a focal point. The authors discuss the importance of prioritizing a line of scholarship surrounding how to convey theory in such a way that it better informs pedagogy as well as the processes of evaluation, planning, and intervention. This comprehensive historical review serves to orient occupational therapy scholars to the past and present state of theory while also shedding light on its necessary inclusion in future scholarship

GRIPS - Gamma-Ray Imaging, Polarimetry and Spectroscopy

We propose to perform a continuously scanning all-sky survey from 200 keV to 80 MeV achieving a sensitivity which is better by a factor of 40 or more compared to the previous missions in this energy range. The Gamma-Ray Imaging, Polarimetry and Spectroscopy (GRIPS) mission addresses fundamental questions in ESA's Cosmic Vision plan. Among the major themes of the strategic plan, GRIPS has its focus on the evolving, violent Universe, exploring a unique energy window. We propose to investigate $\gamma$-ray bursts and blazars, the mechanisms behind supernova explosions, nucleosynthesis and spallation, the enigmatic origin of positrons in our Galaxy, and the nature of radiation processes and particle acceleration in extreme cosmic sources including pulsars and magnetars. The natural energy scale for these non-thermal processes is of the order of MeV. Although they can be partially and indirectly studied using other methods, only the proposed GRIPS measurements will provide direct access to their primary photons. GRIPS will be a driver for the study of transient sources in the era of neutrino and gravitational wave observatories such as IceCUBE and LISA, establishing a new type of diagnostics in relativistic and nuclear astrophysics. This will support extrapolations to investigate star formation, galaxy evolution, and black hole formation at high redshifts.Comment: to appear in Exp. Astron., special vol. on M3-Call of ESA's Cosmic Vision 2010; 25 p., 25 figs; see also www.grips-mission.e

Balancing Efficacy and Effectiveness with Philosophy, History, and Theory-Building in Occupational Therapy Education Research

The preferred focus for education research in occupational therapy increasingly rests on studies that investigate efficacy and effectiveness in the teaching-learning context. While important, the almost exclusive promotion of outcomes-focused studies can come at the expense of other forms of inquiry, including philosophy, history, and theory-building. To fully inform education and enhance practice, outcomes-focused research needs the conceptual foundation provided by philosophical, historical, and theory-building studies. In this paper, the authors suggest that the research enterprise in occupational therapy education is in its infancy and, therefore, quite susceptible to shortcuts that head straight to outcomes. To address this issue, the authors promote an approach where theory-building studies and philosophical explorations both precede and enrich all research endeavors, including those aimed at identifying “what works” in professional education