Variable coordination of amine functionalised N-heterocyclic carbene ligands to Ru, Rh and Rr: C-H and N-H activation and catalytic transfer hydrogenation

Chelating amine and amido complexes of late transition metals are highly valuable bifunctional catalysts in organic synthesis, but complexes of bidentate amine–NHC and amido–NHC ligands are scarce. Hence, we report the reactions of a secondary-amine functionalised imidazolium salt 2a and a primary-amine functionalised imidazolium salt 2b with [( p -cymene)RuCl 2 ] 2 and [Cp*MCl 2 ] 2 (M = Rh, Ir). Treating 2a with [Cp*MCl 2 ] 2 and NaOAc gave the cyclometallated compounds Cp*M(C,C)I (M = Rh, 3 ;M = Ir, 4 ), resulting from aromatic C–H activation. In contrast, treating 2b with [( p -cymene)RuCl 2 ] 2 ,Ag 2 O and KI gave the amine–NHC complex [( p -cymene)Ru(C,NH 2 )I]I ( 5 ). The reaction of 2b with [Cp*MCl 2 ] 2 (M = Rh, Ir), NaO t Bu and KI gave the amine–NHC complex [Cp*Rh(NH 2 )I]I ( 6 ) or the amido–NHC complex Cp*Ir(C,NH)I ( 7 ); both protonation states of the Ir complex could be accessed: treating 7 with trifluoroacetic acid gave the amine–NHC complex [Cp*Ir(C,NH 2 )I][CF 3 CO 2 ]( 8 ). These are the first primary amine– or amido–NHC complexes of Rh and Ir. Solid-state structures of the complexes 3–8 have been determined by single crystal X-ray diffraction. Complexes 5 , 6 and 7 are pre-catalysts for the catalytic transfer hydrogenation of acetophenone to 1-phenylethanol, with ruthenium complex 5 demonstrating especially high reactivity

Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming implications, especially with regards to Gram-negative bacteria. An international task force from 79 different countries has joined this project by sharing a document on the rational use of antimicrobials for patients with IAIs. The project has been termed AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections). The authors hope that AGORA, involving many of the world's leading experts, can actively raise awareness in health workers and can improve prescribing behavior in treating IAIs

Exact impulsive gravitational waves in spacetimes of constant curvature

Exact solutions exist which describe impulsive gravitational waves propagating in Minkowski, de Sitter, or anti-de Sitter universes. These may be either nonexpanding or expanding. Both cases in each background are reviewed here from a unified point of view. All the main methods for their construction are described systematically: the Penrose "cut and paste" method, explicit construction of continuous coordinates, distributional limits of sandwich waves, embedding from higher dimensions, and boosts of sources or limits of infinite accelerations. Attention is concentrated on the most interesting specific solutions. In particular, the nonexpanding impulsive waves that are generated by null multipole particles are described. These generalize the well-known Aichelburg-Sexl and Hotta-Tanaka monopole solutions. Also described are the expanding spherical impulses that are generated by snapping and colliding strings. Geodesics and some other properties of impulsive wave spacetimes are also summarized.Comment: 33 pages, LaTeX 2e, in Gravitation: Following the Prague Inspiration (To celebrate the 60th birthday of Jiri Bicak), O.Semerak, J.Podolsky, M.Zofka (eds.), World Scientific, Singapore, to appear in 2002, pp 205-24

The role of interfaces in CoFe/IrMn exchange biased systems

A trilayer system consisting of an IrMn layer exchanged coupled to two CoFe layers of equal thickness has been studied. A single stage reversal was observed over a wide range of temperatures. Two bilayers with the same thicknesses of the pinning layer but different ferromagnetic thicknesses were also studied. By comparing the magnetic properties of these three stacks the effect of the interfacial area on the exchange field and the coercivity has been determined. We find that the interfacial area has a very minor effect on the exchange field H-ex and the blocking temperature (T-B) but causes a doubling of the coercivity (H-c). This indicates that H-c is dominated by the interface whereas the exchange bias is controlled by volumetric effects

An invitation to grieve: reconsidering critical incident responses by support teams in the school setting

This paper proposes that consideration could be given to an invitational intervention rather than an expectational intervention when support personnel respond to a critical incident in schools. Intuitively many practitioners know that it is necessary for guidance/counselling personnel to intervene in schools in and following times of trauma. Most educational authorities in Australia have mandated the formulation of a critical incident intervention plan. This paper defines the term critical incident and then outlines current intervention processes, discussing the efficacy of debriefing interventions. Recent literature suggests that even though it is accepted that a planned intervention is necessary, there is scant evidence as to the effectiveness of debriefing interventions in stemming later symptoms of post traumatic stress disorder. The authors of this paper advocate for an expressive therapy intervention that is invitational rather than expectational, arguing that not all people respond to trauma in the same way and to expect that they will need to recall and retell what has happened is most likely a dangerous assumption. A model of invitation using Howard Gardner’s (1983) multiple intelligences is proposed so that students are invited to grieve and understand emotionally what is happening to them following a critical incident

Bones as evidence of meat production and distribution in York

[First Paragraphs] Many books and papers have been written on the general principles and minutiae of using the animal bones recovered from archaeological deposits as a source of information on past diet.A full discussion of methodological issues is beyond the remit of this chapter, but it is worth reminding ourselves that there are many stages between an animal being killed and used for food, and a pile of bones arriving on the bench. There is the initial stage of decision-making on the part of the human population, and of individuals within it, and possibly on the part of the animals as well. Those decisions bring people and animaIs together ar the point of the animals' death, and may well be what we are seeking to infer from the archaeological record. After slaughter, animals of any size will be butchered in various ways, and parts of one carcass may be traded or redistributed to several locations, at each of which different people will take further decisions as to recipe and utilization. Some bones will have been separared from the carcass during initial butchering, and will be disposed of fairly immediately. After consumption (and different individuals will have different ideas as to what is worth eating), the remaining bones and other waste might be used in some orher way (soup, glue, toothpicks), before being destroyed or deposited in some dump or refuse pit. Micro-organisms and geochemical agents then set to work, modifying and destroying some or all bone fragments through the centuries, until a residue reaches a tenuous equilibrium with the sediment around it, and survives until the archaeologists arrive on site

Unstable Identities: The European Court of Human Rights and the Margin of Appreciation

All legal systems work under a master narrative – the self-conception of most actors of the system itself. A master narrative is a short and simple story and it is the underlying premise upon which any legal system is based. It is a simple story because it paints the system in quick broad brushstrokes and at (most) times is oblivious to the paradoxes within it. Furthermore, a master narrative is important for legitimization purposes because the actors’ legitimacy will depend on their (perceived) conformity with the system’s master narrative. Therefore, legitimacy is self-referential; the yardsticks for a legitimate action are contained within the system’s master narrative, not outside of it. When talking about different international courts it is important to remember that they are embedded within a master narrative that is contextual and contingent and, at different points, more or less contested. This paper explores the question of what happens when the master-narrative is in a period of transition (from a state cantered to a post-national world order) and when the actors’ legitimacy, their interpretative endeavours the very fundamentals are in a state of flux. I use the margin of appreciation discussion as a focal point of describing the conflicting narratives under which the European Court of Human Rights works, narratives in which the different actors (judges, attorneys, NGO activists, government agents) and their consequences in terms of the interpretation of the European Convention on Human Rights

Animal bones from Anglo-Scandinavian York

INTRODUCTION: This chapter provides an overview of the current state of knowledge regarding vertebrate animals in and around York in the Anglo-Scandinavian period. The great majority of the available evidence derives from 16-22 Coppergate (AY 15/3), with smaller amounts of data from a number of excavations around the city. The aim is not to describe the data at length, but to review the information inferred from those data under several thematic headings. Examination of the material from Coppergate began as the excavation neared its end, early in the 1980s. At that time, our knowledge of urban zooarchaeology in Britain rested on just a few major studies (e.g. Exeter, Maltby 1979; Southampton, Bourdillon and Coy 1980; Baynards Castle, London, Armitage 1977), and little or nothing was known about Anglo-Scandinavian husbandry. The intervening 30 years has seen the publication of many substantial assemblages from 8th- to 15th century urban contexts across northern Europe (e.g. Birka, Ericson et al. 1988; Ribe, Hatting 1991; Waterford, McCormick 1997; Lubeck, Rheingans and Reichstein 1991; Compiegne, Yvinec 1997). With that increasing information has come some shift in emphasis from data such as the relative abundance of different taxa and changes through time, to more thematic questions of supply and demand, and the value of animal bones in discussions on the emergence of towns and their associated social structures (e.g. Bourdillon 1984; O'Connor 1994; Crabtree 1990). This review therefore revisits previously published material, and incorporates additional data in a synthesis of evidence from York as a whole, and in regional comparisons. Practical methods are not discussed at length here: they are detailed by site in the appropriate fascicules of AY 15/1-5, and reviewed in AY 19/2